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Vipparthi, Santosh Kumar, and S. K. Nagar. "Expert image retrieval system using directional local motif XoR patterns." Expert Systems with Applications 41, no. 17 (2014): 8016–26. http://dx.doi.org/10.1016/j.eswa.2014.07.001.
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V., Lakshmi Surekha* &. M. Pradeep. "A NEW ADVANCED APPROACH FOR CONTENT BASED IMAGE RETRIEVAL USING TEXTON PATTERN." INTERNATIONAL JOURNAL OF RESEARCH SCIENCE & MANAGEMENT 4, no. 6 (2017): 129–35. https://doi.org/10.5281/zenodo.820831.
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In this paper, a new advanced approach for content based image retrieval using texon pattern is proposed. The proposed method collects the texton pattern which gives the structure of the query image or database image. First, the color image is converted into HSV (hue, saturation and value) color space. Second, the V color space is divided into overlapping sub blocks of size 2 × 2 and textons are collected based on the shape of the textons. Then, local binary pattern operation is performed on the texton image between the center pixel and its surrounding neighbors. Finally, the feature vector is constructed based on the contourlet transform and local binary pattern. The performance of the proposed method is evaluated by testing on benchmark database, Corel-1K, Corel-5K and Corel-10K in terms of precision, recall, average retrieval precision and average retrieval rate.The results after investigation show a significant improvement as compared to the state-of-the-art features for image retrieval.
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Bala, Anu, and Tajinder Kaur. "Local texton XOR patterns: A new feature descriptor for content-based image retrieval." Engineering Science and Technology, an International Journal 19, no. 1 (2016): 101–12. http://dx.doi.org/10.1016/j.jestch.2015.06.008.
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HARIPRASAD, REDDY A., and SUBHASH CHANDRA N. "LOCAL ORIENTATION GRADIENT XOR PATTERNS: A NEW FEATURE DESCRIPTOR FOR IMAGE INDEXING AND RETRIEVAL." i-manager’s Journal on Pattern Recognition 2, no. 4 (2016): 1. http://dx.doi.org/10.26634/jpr.2.4.5943.
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Janakiraman, Bhavithra, Sathiyapriya Shanmugam, Rocío Pérez de Prado, and Marcin Wozniak. "3D Road Lane Classification with Improved Texture Patterns and Optimized Deep Classifier." Sensors 23, no. 11 (2023): 5358. http://dx.doi.org/10.3390/s23115358.
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The understanding of roads and lanes incorporates identifying the level of the road, the position and count of lanes, and ending, splitting, and merging roads and lanes in highway, rural, and urban scenarios. Even though a large amount of progress has been made recently, this kind of understanding is ahead of the accomplishments of the present perceptual methods. Nowadays, 3D lane detection has become the trending research in autonomous vehicles, which shows an exact estimation of the 3D position of the drivable lanes. This work mainly aims at proposing a new technique with Phase I (road or non-road classification) and Phase II (lane or non-lane classification) with 3D images. Phase I: Initially, the features, such as the proposed local texton XOR pattern (LTXOR), local Gabor binary pattern histogram sequence (LGBPHS), and median ternary pattern (MTP), are derived. These features are subjected to the bidirectional gated recurrent unit (BI-GRU) that detects whether the object is road or non-road. Phase II: Similar features in Phase I are further classified using the optimized BI-GRU, where the weights are chosen optimally via self-improved honey badger optimization (SI-HBO). As a result, the system can be identified, and whether it is lane-related or not. Particularly, the proposed BI-GRU + SI-HBO obtained a higher precision of 0.946 for db 1. Furthermore, the best-case accuracy for the BI-GRU + SI-HBO was 0.928, which was better compared with honey badger optimization. Finally, the development of SI-HBO was proven to be better than the others.
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Muratore, Paolo, Cristiano Capone, and Pier Stanislao Paolucci. "Target spike patterns enable efficient and biologically plausible learning for complex temporal tasks." PLOS ONE 16, no. 2 (2021): e0247014. http://dx.doi.org/10.1371/journal.pone.0247014.
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Recurrent spiking neural networks (RSNN) in the brain learn to perform a wide range of perceptual, cognitive and motor tasks very efficiently in terms of energy consumption and their training requires very few examples. This motivates the search for biologically inspired learning rules for RSNNs, aiming to improve our understanding of brain computation and the efficiency of artificial intelligence. Several spiking models and learning rules have been proposed, but it remains a challenge to design RSNNs whose learning relies on biologically plausible mechanisms and are capable of solving complex temporal tasks. In this paper, we derive a learning rule, local to the synapse, from a simple mathematical principle, the maximization of the likelihood for the network to solve a specific task. We propose a novel target-based learning scheme in which the learning rule derived from likelihood maximization is used to mimic a specific spatio-temporal spike pattern that encodes the solution to complex temporal tasks. This method makes the learning extremely rapid and precise, outperforming state of the art algorithms for RSNNs. While error-based approaches, (e.g. e-prop) trial after trial optimize the internal sequence of spikes in order to progressively minimize the MSE we assume that a signal randomly projected from an external origin (e.g. from other brain areas) directly defines the target sequence. This facilitates the learning procedure since the network is trained from the beginning to reproduce the desired internal sequence. We propose two versions of our learning rule: spike-dependent and voltage-dependent. We find that the latter provides remarkable benefits in terms of learning speed and robustness to noise. We demonstrate the capacity of our model to tackle several problems like learning multidimensional trajectories and solving the classical temporal XOR benchmark. Finally, we show that an online approximation of the gradient ascent, in addition to guaranteeing complete locality in time and space, allows learning after very few presentations of the target output. Our model can be applied to different types of biological neurons. The analytically derived plasticity learning rule is specific to each neuron model and can produce a theoretical prediction for experimental validation.
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Ekelmans, Pierre, Nataliya Kraynyukovas, and Tatjana Tchumatchenko. "Targeting operational regimes of interest in recurrent neural networks." PLOS Computational Biology 19, no. 5 (2023): e1011097. http://dx.doi.org/10.1371/journal.pcbi.1011097.
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Neural computations emerge from local recurrent neural circuits or computational units such as cortical columns that comprise hundreds to a few thousand neurons. Continuous progress in connectomics, electrophysiology, and calcium imaging require tractable spiking network models that can consistently incorporate new information about the network structure and reproduce the recorded neural activity features. However, for spiking networks, it is challenging to predict which connectivity configurations and neural properties can generate fundamental operational states and specific experimentally reported nonlinear cortical computations. Theoretical descriptions for the computational state of cortical spiking circuits are diverse, including the balanced state where excitatory and inhibitory inputs balance almost perfectly or the inhibition stabilized state (ISN) where the excitatory part of the circuit is unstable. It remains an open question whether these states can co-exist with experimentally reported nonlinear computations and whether they can be recovered in biologically realistic implementations of spiking networks. Here, we show how to identify spiking network connectivity patterns underlying diverse nonlinear computations such as XOR, bistability, inhibitory stabilization, supersaturation, and persistent activity. We establish a mapping between the stabilized supralinear network (SSN) and spiking activity which allows us to pinpoint the location in parameter space where these activity regimes occur. Notably, we find that biologically-sized spiking networks can have irregular asynchronous activity that does not require strong excitation-inhibition balance or large feedforward input and we show that the dynamic firing rate trajectories in spiking networks can be precisely targeted without error-driven training algorithms.
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Meng, Zhaohui, and Xiaodong Gu. "Palm-Dorsal Vein Recognition Method Based on Histogram of Local Gabor Phase XOR Pattern with Second Identification." Journal of Signal Processing Systems 73, no. 1 (2013): 101–7. http://dx.doi.org/10.1007/s11265-013-0734-6.
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Bedina, S., A. Trofimenko, E. Mozgovaya, S. Spitsina, and M. Mamus. "AB0027 XANTHINE OXIDOREDUCTASE: ENZYME PROFILE OF PLASMA AND LYMPHOCYTES IN RHEUMATOID ARTHRITIS." Annals of the Rheumatic Diseases 81, Suppl 1 (2022): 1148.1–1148. http://dx.doi.org/10.1136/annrheumdis-2022-eular.2667.
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BackgroundDisorders of acquired and adaptive immunity play an important role in the rheumatoid arthritis (RA) pathogenesis. Important changes can nevertheless be detected at the metabolic level in the immune cells along with immune disorders. The imbalance between generation and neutralization of the free radicals during oxidative stress may cause damage of both cellular structures and components of extracellular matrix. One of principal free radical generators is xanthine oxidoreductase (XOR), the prooxidant enzyme complex which could be active either in its oxidase or dehydrogenase form. The study of plasma and lymphocytic xanthine oxidase (XO) and xanthine dehydrogenase (XDG) activities is of emerging interest because of their putative role in initiation and chronization of RA.ObjectivesEvaluation the relationship between RA activity and XO and XDG activities using both plasma and lysed lymphocyte samples.MethodsThe research was carried out in agreement with the WMA Declaration of Helsinki principles after the local ethical board approval. RA diagnosis was verified using ACR/EULAR criteria (2010). RA activity was measured using the Disease Activity Score of 28 joints (DAS28). Blood lymphocytes were isolated by means of density gradient centrifugation in lymphosep (JCN Biomedicals), 1.077-1.079 g/ml. XO (ЕС 1.17.3.2) and XDG (ЕС 1.17.1.4) activities in plasma and lysed lymphocytes were measured using spectrophotometric techniques and expressed as nmol/ml/min [1]. Data are presented as median and quartiles (Me (Q25; Q75). Differences were considered significant when p<0.05.Results77 RA patients (57 women and 20 men) were enrolled in the study. Mean age of patients was 45 (37; 49) years, mean RA duration was 8 (6; 10) years. 16 (21%) RA patients had low disease activity, 49 (63%) patients moderate, and 12 (16%) patients had high one. 30 (19 women and 16 men) healthy persons comprised the control group. Reference ranges for plasma XO and XDG activities were 2.60–3.96 nmol/min/ml and 4.49–5.93 nmol/min/ml, respectively. Reference ranges for XO and XDG activities in lysed lymphocytes were 14.11-31.33 nmol/min/ml and 18.62-39.64 nmol/min/ml, respectively. Plasma enzymatic pattern in RA patients was characterized by increase in XO activity (p<0.001) and a somewhat decrease in XDG activity (p=0.059). Lymphocytic enzymatic pattern in RA patients was characterized by decreased activity of both enzymes (p<0.001 for both cases). Plasma XO activity was increased and lymphocytic XO activity was decreased in all the grades of RA activity. XO activity reached its highest changes at maximum disease activity. Plasma XDG activity was increased in low disease activity (р<0.001), while patients with moderate or high disease activities were characterized by decreased activity of this enzyme (р=0.008). Lymphocytic XDG activity was decreased in all the grades of disease activity (р<0.001). XDG activity reached its highest changes at maximum disease activity. Activities of XO and XDG in lymphocytes negatively correlated with RA activity. Activities of XO in plasma positively correlated with RA activity, while XDG activity negatively correlated with RA activity.ConclusionPlasmatic and lymphocytic enzymatic patterns in RA patients were characterized by multidirectional changes of XO and XDG activities. Multiple correlations were found between RA activity and enzyme activities in both studied compartments. These changes in oxidant enzyme activities may point at involvement of free radical oxidation in the RA pathogenesis. Free radical generation triggers metabolic cascades that lead to cell damage, premature death, promote endothelial dysfunction, extracellular neutrophil trap formation, support chronic inflammation and joint destruction, and other organs and systems under oxidative stress.References[1]Mozgovaya E.E., et al. Siberian Journal of Life Sciences and Agriculture 2021; 13(3):288-304.Disclosure of InterestsNone declared
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Aqel, Amin A., Tala M. Al-Matarneh, Tayf K. Al-Tarawneh, Tahrir Alnawayseh, Mohammed Alsbou, and Yasser Gaber. "Monitoring of Antibiotic Resistance Patterns Within Al-Karak Governmental Hospital, Jordan, in 2022." Antibiotics 13, no. 12 (2024): 1172. https://doi.org/10.3390/antibiotics13121172.
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Background/Objectives: Antimicrobial resistance is considered one of the foremost global public health challenges, and its prevalence is increasing. In Jordan, particularly in Al-Karak Governorate, there is a lack of sufficient data on antimicrobial resistance to make accurate assessments. The main aim of the current study was to evaluate antibiotic resistance trends in clinical specimens from 2022 and assess antibiotic resistance patterns. The emphasis on the WHO antibiotic classification as Access, Watch, and Reserved (AWaRe) was adopted in the current study. Results: Among Gram-positive bacteria, Enterococcus faecalis exhibited 100% susceptibility to nitrofurantoin and 96% to vancomycin, Streptococcus viridans exhibited 100% susceptibility to teicoplanin, while CoNS (coagulase-negative Staphylococci) showed moderate resistance to Trimethoprim + Sulfamethoxazole (63%) and clindamycin (47%). Among Gram-negative bacteria, Escherichia coli and Klebsiella pneumoniae displayed high susceptibility to fosfomycin (E. coli: 95%, K. pneumoniae: 80%) and amikacin (E. coli: 93%, K. pneumoniae: 81%). Resistance was notable for trimethoprim + sulfamethoxazole (E. coli: 47%, K. pneumoniae: 53%) and nitrofurantoin (K. pneumoniae: 30%). Pseudomonas aeruginosa exhibited the highest proportion of XDR strains (15%), followed by K. pneumoniae (11%) and E. coli (4%), while PDR strains were found in P. aeruginosa (6%), K. pneumoniae (3%), and E. coli (0.6%). XDR was observed in 4% of CoNS and 3% of S. viridans (α), with Staphylococcus aureus exhibiting both XDR and PDR at 1%. Methods: A cross-sectional retrospective study of bacterial species and their antimicrobial susceptibility was carried out at a hospital in Al Karak, Jordan, from January to December of 2022, the study included 1187 isolates from all locations in Al-Karak Governmental Hospital. Conclusions: The significant prevalence of XDR and PDR strains in key pathogens, particularly P. aeruginosa and K. pneumoniae, underscores the need for a robust Antimicrobial Stewardship Program (ASP) and infection control measures at Al-Karak Governmental Hospital. High susceptibility in several Access group antibiotics (e.g., amikacin and nitrofurantoin) supports their prioritization in empirical therapy, while the emergence of resistance in Watch and Reserved antibiotics highlights the necessity for rational use. These findings are very important for adjusting the local strategies to lower the spread of resistant strains and improve clinical outcomes.
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Ahmed, Imran, Kauser Jabeen, Raunaq Inayat, and Rumina Hasan. "Susceptibility Testing of Extensively Drug-Resistant and Pre-Extensively Drug-Resistant Mycobacterium tuberculosis against Levofloxacin, Linezolid, and Amoxicillin-Clavulanate." Antimicrobial Agents and Chemotherapy 57, no. 6 (2013): 2522–25. http://dx.doi.org/10.1128/aac.02020-12.
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ABSTRACTPakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR)Mycobacterium tuberculosisagainst LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC.M. tuberculosisH37Rv was used as a control strain. A total of 102M. tuberculosisisolates (XDR,n= 59; pre-XDR,n= 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases.
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Pitchaiyan, Shanthi, and Nickolas Savarimuthu. "Deep Stacked Autoencoder-Based Automatic Emotion Recognition Using an Efficient Hybrid Local Texture Descriptor." Journal of Information Technology Research 15, no. 1 (2022): 1–26. http://dx.doi.org/10.4018/jitr.2022010103.
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Extracting an effective facial feature representation is the critical task for an automatic expression recognition system. Local Binary Pattern (LBP) is known to be a popular texture feature for facial expression recognition. However, only a few approaches utilize the relationship between local neighborhood pixels itself. This paper presents a Hybrid Local Texture Descriptor (HLTD) which is derived from the logical fusion of Local Neighborhood XNOR Patterns (LNXP) and LBP to investigate the potential of positional pixel relationship in automatic emotion recognition. The LNXP encodes texture information based on two nearest vertical and/or horizontal neighboring pixel of the current pixel whereas LBP encodes the center pixel relationship of the neighboring pixel. After logical feature fusion, the Deep Stacked Autoencoder (DSA) is established on the CK+, MMI and KDEF-dyn dataset and the results show that the proposed HLTD based approach outperforms many of the state of art methods with an average recognition rate of 97.5% for CK+, 94.1% for MMI and 88.5% for KDEF.
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Aboud, Said, Simon N. Buhalata, Onduru G. Onduru, et al. "Antimicrobial Susceptibility Testing Patterns of Neisseria gonorrhoeae from Patients Attending Sexually Transmitted Infections Clinics in Six Regions in Tanzania." Tropical Medicine and Infectious Disease 7, no. 6 (2022): 89. http://dx.doi.org/10.3390/tropicalmed7060089.
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Antimicrobial resistance (AMR) is global health threat that is on the increase, and it has been adversely affecting the proper management of sexually transmitted infections (STI). Data on antimicrobial susceptibility testing patterns of N. gonorrhoeae are limited in local settings. We determined in vitro antimicrobial susceptibility and phenotypic profiles of N. gonorrhoeae isolated from STI/Outpatient Department (OPD) clinics. Minimum Inhibitory Concentrations (MIC) (µg/mL) were determined using E-Test and agar dilution methods for previously and currently recommended antimicrobial agents. A total of 164 N. gonorrhoeae isolates from urethral discharge and endocervical swabs were tested. The prevalence of resistant N. gonorrhoeae to tetracycline, norfloxacin, penicillin and ciprofloxacin were 98.6%, 82.2%, 84.3% and 75.6%, respectively. None of the isolates was resistant to kanamycin. Penicillinase producing N. gonorrhoeae (PPNG) was found to be 73.7%, with 56.7% and 43.3% observed among isolates from women and men, respectively. Tetracycline resistant-N. gonorrhoeae (TRNG) was found to be 34.0%, and QRNG with HLR to ciprofloxacin was 79.9%. The overall MDR-NG was 79.9%, and XDR-NG was 3.6%. MIC50 and MIC90 were 4.0 and 8.0 and 2.0 and 4.0 µg/mL for ciprofloxacin and norfloxacin, respectively. Dendrograms showed that 44 phenotypic groups are associated with a high rate of AMR among high MDR-NG and moderate XDR-NG isolates. The predominant groups of quinolone-resistant N. gonorrhoeae (QRNG)+PPNG (34.7%) and QRNG+PPNG+TRNG (32.9%) were observed among the isolates having HLR to ciprofloxacin. We reported a high prevalence of AMR (>90%) to previously recommended antimicrobials used for the treatment of gonorrhoea. Multidrug resistant N. gonorrhoeae (MDR-NG) was highly reported, and extensively drug resistant (XDR-NG) has gradually increased to the currently recommended cephalosporins including ceftriaxone and cefixime. Heterogeneous groups of QRNG+PPNG+ and QRNG+PPNG+TRNG were highly resistant to penicillin, tetracycline, ciprofloxacin and norfloxacin. A surveillance program is imperative in the country to curb the spread of AMR.
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Daniyarov, Asset, Ainur Akhmetova, Saule Rakhimova, et al. "Whole-Genome Sequence-Based Characterization of Pre-XDR M. tuberculosis Clinical Isolates Collected in Kazakhstan." Diagnostics 13, no. 12 (2023): 2005. http://dx.doi.org/10.3390/diagnostics13122005.
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Background: Kazakhstan has a high burden of multidrug-resistant tuberculosis in the Central Asian region. This study aimed to perform genomic characterization of Mycobacterium tuberculosis strains obtained from Kazakhstani patients with pre-extensively drug-resistant tuberculosis diagnosed in Kazakhstan. Methods: Whole-genome sequencing was performed on 10 pre-extensively drug-resistant M. tuberculosis strains from different regions of Kazakhstan. All strains had high-confidence resistance mutations according to the resistance grading system previously established by the World Health Organization. The genome analysis was performed using TB-Profiler, Mykrobe, CASTB, and ResFinder. Results: Valuable information for understanding the genetic diversity of tuberculosis in Kazakhstan can also be obtained from whole-genome sequencing. The results from the Phenotypic Drug Susceptibility Testing (DST) of bacterial strains were found to be consistent with the drug resistance information obtained from genomic data that characterized all isolates as pre-XDR. This information can help in developing targeted prevention and control strategies based on the local epidemiology of tuberculosis. Furthermore, the data obtained from whole-genome sequencing can help in tracing the transmission pathways of tuberculosis and facilitating early detection of outbreaks. Conclusions: The results from whole-genome sequencing of tuberculosis clinical samples in Kazakhstan provide important insights into the drug resistance patterns and genetic diversity of tuberculosis in the country. These results can contribute to the improvement of tuberculosis control and management programs in Kazakhstan.
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Mehr, Muhammad Tariq, Ahmad Zuhayr, Qamar Un Nisa, Shehrbano Raza, and Areeb Iqbal. "Is Salmonella Typhi Becoming a Superbug? A Cross-Sectional Study of the Antibiotic Sensitivity." BMC Journal of Medical Sciences 4, no. 2 (2023): 100–104. https://doi.org/10.70905/bmcj.04.02.0139.
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Objective: To determine the antibiotic sensitivity patterns of Salmonella typhi in blood cultures of the patients attending a tertiary care hospital. Material & Methods: This cross-sectional study was conducted in the Department of Internal Medicine, Hayatabad Medical Complex, Peshawar, Pakistan for a period of one year from 1st August, 2021 till 30 August, 2022. All adult patients of either sex, belonging to the province of Khyber Pakhtunkhwa, Pakistan between 18 to 70 years of age, whether admitted through casualty or the outpatients, having a history of fever for the past 07 days and no prior history of admission or use of antibiotics in past one month were included. Results: The mean age of the patients was 47 ± 5.6 years with females 59.2 % (320) and the males 40.7 % (220). A total of 540 blood cultures showed a growth of Salmonella Typhi out of requested 857 cultures representing a positive culture yield of 63%. The total numbers of MDR cases were 83.6% whereas the XDR cases were 3%. The antibiotics sensitivity was 100% to Carbepenems, Tigacycline, Colistin and Polymixin, whereas between 27.7% to 16.4% in the cephalosporin class and only 16.4% to the flouroquinolones. Conclusion: The antibiotics resistance against Salmonella Typhi is on the upswing and calls for effective programs of antibiotics stewardship, development of indigenous updated antibiotics guidelines in line with the local sensitivity patterns and actions to avert the spread of infection.
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Auganova, Dana, Sabina Atavliyeva, Asylulan Amirgazin, Akmaral Akisheva, Anna Tsepke, and Pavel Tarlykov. "Genomic Characterization of Drug-Resistant Mycobacterium tuberculosis L2/Beijing Isolates from Astana, Kazakhstan." Antibiotics 12, no. 10 (2023): 1523. http://dx.doi.org/10.3390/antibiotics12101523.
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Kazakhstan ranks among the countries with the highest number of MDR-TB patients per 100,000 population worldwide. The successful transmission of local MDR strains of Mycobacterium tuberculosis (Mtb) poses a significant threat to disease control. In this study, we employed whole-genome sequencing to examine drug resistance, compensatory mutations, population structure, and transmission patterns in a sample of 24 clinical isolates of L2/Beijing Mtb collected in Astana, Kazakhstan between 2021 and 2022. The genotypic prediction of Mtb susceptibility to anti-TB agents was consistent with the phenotypic susceptibility, except for bedaquiline. An analysis of resistance-associated genes characterized most of the isolates as pre-extensively drug-resistant tuberculosis (pre-XDR-TB) (n = 15; 62.5%). The phylogenetic analysis grouped the isolates into four transmission clusters; the dominant cluster was assigned to the “aggressive” Central Asia outbreak (CAO) clade of L2/Beijing (n = 15; 62.5%). Thirteen mutations with putative compensatory effects were observed exclusively in Mtb isolates containing the rpoB S450L mutation. The putative compensatory mutations had a stabilizing effect on RpoABC protein stability and dynamics. The high prevalence of the CAO clade in the population structure of Mtb may explain the rapid spread of MDR-TB in Kazakhstan.
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Jalali, Yashar, Andrea Kološová, Adriána Liptáková, et al. "Is It Time to Start Worrying? A Comprehensive Report on the Three-Year Prevalence of ESBL-Producing Bacteria and Their Trends in Antibiotic Resistance from the Largest University Hospital in Slovakia." Pharmaceuticals 17, no. 11 (2024): 1517. http://dx.doi.org/10.3390/ph17111517.
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Background/Objectives: Over the past few decades, extended-spectrum β-lactamase (ESBL)-producing bacteria have become a great concern in healthcare systems worldwide, imposing large burdens by increasing antimicrobial resistance and patient morbidity. Given the high mortality rates and emergence of multidrug-resistant (MDR) strains, monitoring ESBL prevalence and resistance patterns is crucial. This study aimed to evaluate ESBL-producing Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae over three years, focusing on phenotypic distribution and resistance profiles. Methods: A total of 1599 ESBL-producing bacterial samples were collected and analysed. A panel of 20 antibiotics was tested to determine resistance traits. Data were recorded on phenotypical distribution, isolation types, changes in antibiotic resistance, and the relation of such changes to antibiotic consumption (defined daily dose) from clinical isolates. Results: Phenotypical analysis revealed the minimal presence of the Cefotaximase from Munich (CTX-M) phenotype in E. coli and K. pneumoniae, creating a distinct epidemiological profile compared to global patterns. Shifts in isolation trends, particularly in P. mirabilis, suggest an expected increase in associated-mortality-rate in the coming years. While resistance trends were not statistically significant, MDR and extensively drug-resistant (XDR) strains were identified across all three bacteria. Only meropenem showed consistent 100% efficacy against E. coli, with other antibiotics displaying only partial effectiveness. Conclusions: These findings highlight the need for ongoing surveillance of ESBL-producing bacteria and underscore challenges in managing antibiotic resistance due to limited efficacy of last-resort treatments. The unique phenotypical distribution observed could impact local resistance management strategies in hospital settings in the coming years.
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Anderson, Ian M., Arnulf Muan, and C. Barry Carter. "Microstructural observations of the “Wustite-Spinel” coexistence following quenching of cation-excess spinels, Ni2(1+x)Ti1-xO4." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (1990): 1058–59. http://dx.doi.org/10.1017/s0424820100178422.
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Oxide mixtures which feature a coexistence of phases with the wüstite and spinel structures are considered model systems for the study of solid-state reaction kinetics, phase boundaries, and thin-film growth, and such systems are especially suited to TEM studies. (In this paper, the terms “wüstite” and “spinel” will refer to phases of those structure types.) The study of wüstite-spinel coexistence has been limited mostly to systems near their equilibrium condition, where the assumptions of local thermodynamic equilibrium are valid. The cation-excess spinels of the type Ni2(1+x)Ti1-xO4, which reportedly exist only above 1375°C4, provide an excellent system for the study of wüstite-spinel coexistence under highly nonequilibrium conditions. The nature of these compounds has been debated in the literature. X-ray and neutron powder diffraction patterns have been used to advocate the existence of a single-phase, non- stoichiometric spinel. TEM studies of the microstructure have been used to suggest equilibrium coexistence of a stoichiometric spinel, Ni2TiO4, and a wüstite phase; this latter study has shown a coexistence of wüstite and spinel phases in specimens thought to have been composed of a single, non- stoichiometric spinel phase. The microstructure and nature of this phase coexistence is the focus of this study. Specimens were prepared by ball-milling a mixture of NiO and TiO2 powders with 10 wt.% TiO2. The mixture was fired in air at 1483°C for 5 days, and then quenched to room temperature. The aggregate thus produced was highly porous, and needed to be infiltrated prior to TEM sample preparation, which was performed using the standard techniques of lapping, dimpling, and ion milling.
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Sánchez-Muñoz, Luis, Jesús Sanz, Pierre Florian, Virginia Diez-Gómez, Marta Furio, and Isabel Sobrados. "Order-Disorder in the Structures of Lithium Aluminosilicate Minerals by XRD and Multinuclear NMR." Minerals 12, no. 4 (2022): 427. http://dx.doi.org/10.3390/min12040427.
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The crystal structures of the lithium aluminosilicate minerals of the Li2O–Al2O3–SiO2 (LAS) system (Li1−xAl1−xSi1+xO4 system for 0.0 ≤ x ≤ 1.0), and bikitaite were determined by X-ray diffraction (XRD) in literature, suggesting several possible lattice models for each of the crystallized phases, because of the intrinsic experimental difficulties of this technique. Here, we correlate powder XRD patterns with Rietveld refinement of cell parameters and magic angle sample spinning multinuclear magnetic resonance (NMR) spectra, including 29Si, 27Al, 7Li, and 6Li spectroscopy at 7.05 T, 9.4 T, and 20 T. The aim is to select appropriate lattice models from short-range order schemes in the lithium aluminosilicate phases, from natural minerals and synthetic crystals from the crystallization of amorphous gel precursors by a ceramic route and also by hydrothermal high-pressure experiments. Solid solutions were found in α-quartz and α-cristobalite up to x ≥ 0.75, and in β-eucryptite and β-spodumene for 0.0 ≤ x ≤ 1.0, when the ceramic synthesis is at work. The local structures of these intermediate members of the β-eucryptite and β-spodumene solid-solution series have 29Si NMR spectra consistent with the Loewenstein’s rule, i.e., they have short-range order but are strictly non-periodic structures. However, β-eucryptite LiAlSiO4 end-member has a short-range structure compatible with the long-range order of the P6422 symmetry, when the crystallization is produced at hydrothermal conditions. The local structure of α-spodumene LiAlSi2O6 is consistent with the C2/c model. α-eucryptite LiAlSiO4 shows a short-range structure as that suggested by the R-3 lattice model. Petalite LiAlSi4O10 has a local structure compatible with the P2/a space group. Finally, the 29Si NMR spectra of bikitaite LiAlSi2O6·H2O indicate a short-range structure well-suited with the P1 symmetry. These results are consistent with the Ostwald‘s rule of stages, forming a order-disorder sequence of increasing long-range order from the starting fully disordered solid gels, through crystalline pseudoperiodic structures in non-stoichiometric solid solution crystals that respect the Lowenstein’s rule, up to fully ordered crystals with short-range structures from NMR close to the long-range structures by XRD, as in the stoichiometric compounds found in some natural minerals.
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Prasad, Varpe Aditya Gangule Nitin Thombre Tejas Shahane Shreyas Lokhande. "Tuberculosis: A Survey of Latest Things." International Journal of Pharmaceutical Sciences 2, no. 8 (2024): 3208–19. https://doi.org/10.5281/zenodo.13332535.
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Tuberculosis (TB), an old sickness brought about by the microbes Mycobacterium tuberculosis is as yet liable for more passings overall every year than some other irresistible sickness, including human immunodeficiency infection (HIV) in dislike of accessibility of compelling treatment that has existed for more than a long time since the 1940s. The advancement of protection from anti-toxins is only one of the many provokes confronting the battle to stem this lethal pandemic. Useful factors including an absence of local area mindfulness, admittance to indicative devices, medical services offices, and patient oversight and follow-up are intensified by the infection's wide geographic reach. A disappointment of correspondence and coordination among neighborhood and global control units is similarly risky. As we keep on making perfectly steps in clinical innovation and exploration, there is the requirement for a more prominent work to prepare assets and make enduring, centered ventures of subsidizing and proficient preparation in areas of endemic TB to see an end at last to this microbes' enduring rule of destruction. This survey article takes a gander at the ebb and flow worldwide patterns of the infection from a more extensive point of view.
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Jesús, Antonio Bello Pulido, Cornejo Escobar Pablo, and Rojas-Runjaic Fernando. "Herpetofauna de los parques litorales Laguna de los Patos y Punta Delgada, Cumaná, estado Sucre, Venezuela." Memoria de la Fundacion La Salle de Ciencias Naturales 79, no. 187 (2021): 31–50. https://doi.org/10.5281/zenodo.4687010.
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<strong>Resumen</strong>. La herpetofauna del litoral de Venezuela ha sido poco inventariada y en consecuencia persisten grandes vacíos de información sobre su composición y patrones de distribución de especies. Este estudio tuvo por objeto listar las especies de anfibios y reptiles presentes en los parques litorales Laguna de Los Patos y Punta Delgada, ambos ubicados en la ciudad de Cumaná, estado Sucre, Venezuela. Los muestreos se realizaron irregularmente desde enero 2017 hasta marzo 2019, incluyendo todas las fitocenosis del área y enfatizando en la época de lluvias. Los muestreos se ejecutaron mediante búsqueda libre con captura manual y revisión de animales muertos capturados por habitantes locales. En total se listaron 29 especies (24 reptiles y cinco anfibios). <em>Epictia fallax</em> fue la única endémica, <em>Podocnemis vogli </em>es transferida de otras regiones del país, y otras dos especies son exóticas invasoras (<em>Hemidactylus mabouia </em>y <em>H. frenatus</em>). Además, destaca el uso cinegético de <em>Iguana iguan</em>a y <em>Boa constricto</em>r, ambas en el apéndice II de la CITES. La mayor riqueza de especies se encontró en la Laguna de Los Patos. En cuanto a hábitats, los arbustales xerófilos y manglares albergaron la mayor riqueza, seguidos de los bosques ribereños y herbazales acuáticos; el herbazal psamófilo arrojó el menor número de especies. <strong>Herpetofauna of Laguna de los Patos and Punta Delgada littoral parks, Cumaná, Sucre state, Venezuela</strong> <strong>Abstract</strong>. The herpetofauna of the Venezuelan littoral has been poorly inventoried and consequently, large knowledge gaps on the species composition and distribution patterns still persist. In this study we listed the amphibian and reptile species present in the Laguna de Los Patos and Punta Delgada littoral parks, both located in the city of Cumaná, Sucre state, Venezuela. The samplings were carried out irregularly from January 2017 to March 2019, including all the phytocoenoses of the study area, and with emphasis during the rainy season. We carried out free searches with manual captures and examination of dead animals captured by local people, to sample the species. In total, 29 species were listed (24 reptiles and five amphibians). <em>Epictia fallax</em> was the only endemic, <em>Podocnemis vogli</em> is transferred from other regions of the country, and two other species are exotic invasive (<em>Hemidactylus mabouia</em> and <em>H. frenatus</em>). In addition, the cynegetic use of <em>Iguana iguana</em> and <em>Boa constrictor</em>, both in the appendix II of CITES, stands out. The highest species richness was found in Laguna de Los Patos. Regarding habitats, xerophilous shrubs and mangroves harbored the highest species richness, followed by riparian forests and aquatic grasslands; the psamofilous grassland yielded the least number of species.
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Hasan, Rusul Hussein. "A New Strategy to Modify Hopfield by Using XOR Operation." Baghdad Science Journal, February 20, 2024. http://dx.doi.org/10.21123/bsj.2024.9238.
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The Hopfield network is one of the easiest types, and its architecture is such that each neuron in the network connects to the other, thus called a fully connected neural network. In addition, this type is considered auto-associative memory, because the network returns the pattern immediately upon recognition, this network has many limitations, including memory capacity, discrepancy, orthogonally between patterns, weight symmetry, and local minimum. This paper proposes a new strategy for designing Hopfield based on XOR operation; A new strategy is proposed to solve these limitations by suggesting a new algorithm in the Hopfield network design, this strategy will increase the performance of Hopfield by modifying the architecture of the network, the training and the convergence phases, the proposed strategy based on size of pattern but will avoid learning similar pattern many time, whereas the new strategy XOR shows tolerance in the presence of noise-distorted patterns, infinite storage capacity and pattern inverse value. Experiments showed that the suggested method produced promising results by avoiding the majority of the Hopfield network's limitations. In additional it learns to recognize an infinite number of patterns with varying sizes while preserving a suitable noise ratio.
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Chaitra, B., and P. V. Bhaskar Reddy. "Copy-Move Image Multiple Forgery Detection Based on Transit Flow Regime Algorithm-Enabled ShuffleNet." International Journal of Image and Graphics, January 25, 2025. https://doi.org/10.1142/s0219467827500173.
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The copy-move forgery is considered one among difficult kinds of image forgeries that must be detected. This occurs by duplicating image parts or portions and thereafter adding up again in an image by itself but in other locations. The forgery detection techniques are utilized in image protection while an actual image is not obtainable. The current forgery detection methods detect tampered areas with lesser effectiveness owing to larger size as well as low contrast of images. Here, transit flow regime algorithm-based ShuffleNet (TFRA-ShuffleNet) is presented for multiple forgery detection. In this work, the input image considered is given to multiple object detection. The multiple object detection is carried out in an input image utilizing YOLO V3. After that, features are extracted from object detected image that include local vector pattern (LVP), local optimal-oriented pattern (LOOP), pyramid histogram of oriented gradients (PHoG), local Gabor XOR patterns (LGXP), local directional pattern (LDP), local directional ternary pattern (LDTP) and local binary pattern (LBP). Lastly, multiple forgery detection is conducted employing ShuffleNet. The ShuffleNet is trained to employ TFRA, which is an integration of transit search (TS) and flow regime algorithm (FRA). Furthermore, TFRA-ShuffleNet achieved maximal accuracy, TPR and TNR values of about 96.5%, 96.5% and 97.5%.
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Kumari, Priyanka Sinha, and Kumar Prabhat. "Human Activity Recognition via Optimized Deep learning with Improved Hierarchy of Skeleton." April 14, 2023. https://doi.org/10.5281/zenodo.7827443.
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One of the vast topics is the recognition of human activity that focuses on recognizing a person's particular movement or action based on the sensor data. Due to issues like partial occlusion, background clutter, variations in look, viewpoint, scale, lighting, detecting the human activities from video sequences is a difficult process. A multimodal activity recognition system is required for several applications like human-computer interface, video surveillance systems, and robots for the recognition of human activity. This paper intends to introduce a new human activity recognition model and it involves three process like “(1) Pre-processing, (2) Feature Extraction and (3) Classification”. The pre-processing of input data is done via background subtraction. The pre-processed data are subjected to extract the features, in which an improved hierarchy of skeleton, weighted bag of Visual words, and Local Texton XOR patterns are extracted. Based on the extracted features, the classification process takes place, in which the Optimized Deep Belief Network (DBN) is exploited. For more precise detection, the weight of DBN is optimally tuned via proposed Poor and Rich with Deer Optimization (PRDO) model. Finally, performance of the presented model is computed over the conventional techniques with respect to various performance metrics.
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Muratore, Paolo, Capone Cristiano, and Pier Stanislao Paolucci. "Target spike patterns enable efficient and biologically plausible learning for complex temporal tasks." February 16, 2021. https://doi.org/10.1371/journal.pone.0247014.
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Recurrent spiking neural networks (RSNN) in the brain learn to perform a wide range of perceptual, cognitive and motor tasks very efficiently in terms of energy consumption and their training requires very few examples. This motivates the search for biologically inspired learning rules for RSNNs, aiming to improve our understanding of brain computation and the efficiency of artificial intelligence. Several spiking models and learning rules have been proposed, but it remains a challenge to design RSNNs whose learning relies on biologically plausible mechanisms and are capable of solving complex temporal tasks. In this paper, we derive a learning rule, local to the synapse, from a simple mathematical principle, the maximization of the likelihood for the network to solve a specific task. We propose a novel target-based learning scheme in which the learning rule derived from likelihood maximization is used to mimic a specific spatio-temporal spike pattern that encodes the solution to complex temporal tasks. This method makes the learning extremely rapid and precise, outperforming state of the art algorithms for RSNNs. While error-based approaches, (e.g. e-prop) trial after trial optimize the internal sequence of spikes in order to progressively minimize the MSE we assume that a signal randomly projected from an external origin (e.g. from other brain areas) directly defines the target sequence. This facilitates the learning procedure since the network is trained from the beginning to reproduce the desired internal sequence. We propose two versions of our learning rule: spike-dependent and voltage-dependent. We find that the latter provides remarkable benefits in terms of learning speed and robustness to noise. We demonstrate the capacity of our model to tackle several problems like learning multidimensional trajectories and solving the classical temporal XOR benchmark. Finally, we show that an online approximation of the gradient ascent, in addition to guaranteeing complete locality in time and space, allows learning after very few presentations of the target output. Our model can be applied to different types of biological neurons. The analytically derived plasticity learning rule is specific to each neuron model and can produce a theoretical prediction for experimental validation.
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Muratore, Paolo, Capone Cristiano, and Pier Stanislao Paolucci. "Target spike patterns enable efficient and biologically plausible learning for complex temporal tasks." February 16, 2021. https://doi.org/10.5281/zenodo.4663922.
Full textAbstract:
Recurrent spiking neural networks (RSNN) in the brain learn to perform a wide range of perceptual, cognitive and motor tasks very efficiently in terms of energy consumption and their training requires very few examples. This motivates the search for biologically inspired learning rules for RSNNs, aiming to improve our understanding of brain computation and the efficiency of artificial intelligence. Several spiking models and learning rules have been proposed, but it remains a challenge to design RSNNs whose learning relies on biologically plausible mechanisms and are capable of solving complex temporal tasks. In this paper, we derive a learning rule, local to the synapse, from a simple mathematical principle, the maximization of the likelihood for the network to solve a specific task. We propose a novel target-based learning scheme in which the learning rule derived from likelihood maximization is used to mimic a specific spatio-temporal spike pattern that encodes the solution to complex temporal tasks. This method makes the learning extremely rapid and precise, outperforming state of the art algorithms for RSNNs. While error-based approaches, (e.g. e-prop) trial after trial optimize the internal sequence of spikes in order to progressively minimize the MSE we assume that a signal randomly projected from an external origin (e.g. from other brain areas) directly defines the target sequence. This facilitates the learning procedure since the network is trained from the beginning to reproduce the desired internal sequence. We propose two versions of our learning rule: spike-dependent and voltage-dependent. We find that the latter provides remarkable benefits in terms of learning speed and robustness to noise. We demonstrate the capacity of our model to tackle several problems like learning multidimensional trajectories and solving the classical temporal XOR benchmark. Finally, we show that an online approximation of the gradient ascent, in addition to guaranteeing complete locality in time and space, allows learning after very few presentations of the target output. Our model can be applied to different types of biological neurons. The analytically derived plasticity learning rule is specific to each neuron model and can produce a theoretical prediction for experimental validation.
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Ahmad, Saeed, and Fahmeeda Idrees. "O02 Beyond borders: a global risk analysis of XDR Salmonella Typhi and typhoid outbreaks in Pakistan." JAC-Antimicrobial Resistance 6, Supplement_2 (2024). http://dx.doi.org/10.1093/jacamr/dlae136.002.
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Abstract Background Pakistan has experienced a surge in typhoid outbreaks caused by an emergent strain of XDR Salmonella Typhi since 2016. This strain, resistant to multiple antibiotics including third generation cephalosporins, poses a significant public health threat not only within Pakistan but also globally due to international travel. Understanding the mechanisms of transmission and identifying high-risk regions for importation and onward transmission of XDR S. Typhi are crucial for effective outbreak management and containment efforts. Objectives This study investigates the global risk posed by XDR S. Typhi outbreaks, with a focus on understanding the dynamics of transmission and identifying regions at heightened vulnerability. The research aims to assess the association between air travel patterns from Pakistan and the spread of XDR S. Typhi globally, providing insights for targeted public health interventions. Methods Using data from the District Health Information System (DHIS-2) for reporting priority infectious diseases in Pakistan, this study employs a combination of epidemiological analysis and phylogeographic modelling. Air travel volume data from Pakistan are analysed to discern patterns of XDR S. Typhi transmission to other countries. Phylogeographic models are fitted to identify associations between air travel volume and the movement of the H58 haplotype of S. Typhi. Flight itinerary data are cross-referenced with model-based estimates of typhoid fever incidence to identify countries at highest risk of importation and sustained transmission of XDR S. Typhi. Results The analysis reveals a significant association between air travel volume from Pakistan and the rate of between-country movement of XDR S. Typhi, particularly the H58 haplotype. Countries with strong travel links to Pakistan and efficient local S. Typhi transmission are identified as being at highest risk of importation and sustained onward transmission of XDR S. Typhi. These findings underscore the importance of targeted public health interventions in high-risk countries to mitigate the spread of XDR S. Typhi. Conclusions This study highlights the global threat posed by XDR S. Typhi outbreaks originating in Pakistan. The identification of high-risk countries based on air travel patterns and transmission dynamics provides valuable insights for prioritizing public health activities to track and mitigate the spread of XDR S. Typhi. Efforts to strengthen surveillance, enhance antimicrobial stewardship and improve sanitation infrastructure are critical for preventing and controlling future outbreaks of XDR typhoid on a global scale.
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Bajracharya, Sohani, Ajaya Basnet, Nayanum Pokhrel, Aashish Gupta, and Laxmi Kant Khanal. "Uropathogens and Their Antimicrobial Resistance Profile at a Pediatric Tertiary Care Hospital in Kathmandu, Nepal." American Journal of Tropical Medicine and Hygiene, April 1, 2025. https://doi.org/10.4269/ajtmh.24-0624.
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Urinary tract infections (UTIs) are treated based on local antimicrobial susceptibility patterns; however, growing antimicrobial resistance necessitates continuous monitoring. This retrospective study examined the prevalence of pediatric UTIs, identified causative pathogens, and evaluated their antibiograms and resistance patterns. We examined the demographic data, microbiological profiles, and antimicrobial susceptibility results (September 2019–August 2021) of pediatric patients (neonates to 14 years) with positive urine culture results at Kanti Children’s Hospital, Kathmandu, Nepal, using SPSS version 17.0 (IBM Corp., Armonk, NY). Among 8,072 urine specimens, 575 (7.1%) (95% CI: 6.6–7.7) tested positive for significant infections, primarily from outpatients (88.2%) and males (54.1%), with a median age of 2 years. Most UTIs (93.0%; 535/575) were caused by bacteria, primarily Escherichia coli (78.5%; 420/535). Cumulative resistance rates were 92.4% for penicillin, 69.3% for cephalosporins, 39.7% for quinolones, 30.2% for carbapenems, and 14.3% for aminoglycosides. One hundred sixty-eight (40.0%) E. coli strains and four (33.3%) Pseudomonas aeruginosa strains were multidrug-resistant. Seven (9.0%) Klebsiella pneumoniae strains were extensively drug-resistant (XDR), and 15 (21.1%) were extended-spectrum β-lactamase (ESBL) producers. Multidrug-resistant strains (36.5%; 210/575), XDR strains (22.6%; 15/575), and ESBL producers (14.4%; 83/575) showed >70.0% resistance to ampicillin, cefotaxime-clavulanate, and cefixime. Over the years, resistance to β-lactams has risen, whereas resistance to aminoglycosides, carbapenems, and cotrimoxazole has decreased. Resistance to quinolones has remained consistent. Pediatric UTIs were least common in this hospital, with the majority caused by E. coli. Multidrug-resistant bacteria were more prevalent than XDR and ESBL-producing bacteria. Although resistance to β-lactam antibiotics increased over the years, resistance to aminoglycosides, carbapenems, and cotrimoxazole declined.
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Abdul, Jabar Babatunde Pacome Achimi Agbo, Bayode Romeo Adegbite, Micheska Epola Dibamba Ndanga, et al. "Resistance patterns among drug-resistant tuberculosis patients and trends-over-time analysis of national surveillance data in Gabon, Central Africa." Infection, October 28, 2022. http://dx.doi.org/10.1007/s15010-022-01941-5.
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Abstract Objective Routinely generated surveillance data are important for monitoring the effectiveness of MDR-TB control strategies. Incidence of rifampicin-resistant tuberculosis (RR-TB) is a key indicator for monitoring MDR-TB. Methods In a longitudinal nationwide retrospective study, 8 years (2014–2021) of sputum samples from presumptively drug-resistant tuberculosis patients from all regions of Gabon were referred to the national tuberculosis reference laboratory. Samples were analysed using GeneXpert MTB/RIF and Genotype MTBDRsl version 2/Line Probe Assay. Results Of 3057 sputum samples from presumptive tuberculosis patients, both from local hospital and from referral patients, 334 were RR-TB. The median patient age was 33 years (interquartile range 26–43); one third was newly diagnosed drug-resistant tuberculosis patients; one-third was HIV-positive. The proportion of men with RR-TB was significantly higher than that of women (55% vs 45%; p < 0.0001). Patients aged 25–35 years were most affected (32%; 108/334). The cumulative incidence of RR-TB was 17 (95% CI 15–19)/100,000 population over 8 years. The highest incidences were observed in 2020 and 2021. A total of 281 samples were analysed for second-line drug resistance. The proportions of study participants with MDR-TB, pre-XDR-TB and XDR-TB were 90.7% (255/281), 9% (25/281) and 0.3% (1/281), respectively. The most-common mutations in fluoroquinolones resistance isolates was gyrA double mutation gyrA MUT3B and MUT3C (23%; 4/17). Most (64%; 6/8) second-line injectable drugs resistance isolates were characterised by missing both rrs WT2 and MUT2 banding. Conclusion The increasing incidence of MDR-TB infection in Gabon is alarming. It is highest in the 25–35 years age category. The incidence of MDR-TB infection in treatment-naïve patients calls for case finding and contact tracing strategy improvement.
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Luo, Ting L., Brendan W. Corey, Erik Snesrud, et al. "IS26-mediated plasmid reshuffling results in convergence of toxin–antitoxin systems but loss of resistance genes in XDR Klebsiella pneumoniae from a chronic infection." Microbial Genomics 8, no. 9 (2022). http://dx.doi.org/10.1099/mgen.0.000892.
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Carbapenem-resistant Enterobacterales pose an urgent threat to human health worldwide. Klebsiella pneumoniae sequence type (ST) 14, initially identified in the Middle East and South-Asia and co-harbouring the carbapenemase genes bla OXA-232 and bla NDM-1, is now emerging globally. One such strain was detected in the USA in 2013 from a patient initially treated in India that also carried armA, a 16S rRNA methyltransferase that confers resistance to all clinically relevant aminoglycosides. Genetic and phenotypic changes were observed in 14 serial isolates collected from this chronically infected patient. The index isolate carried five plasmids, including an IncFIB–IncHI1B (harbouring armA and bla NDM-1), an IncFIA (bla CTX-M-15) and a ColE-like (bla OXA-232), and was extensively resistant to antibiotics. Four years later, a subsequent isolate had accumulated 34 variants, including a loss-of-function mutation in romA, resulting in tigecycline non-susceptibility. Importantly, this isolate now only carried two plasmids, including a large mosaic molecule made of fragments, all harbouring distinct toxin–antitoxin systems, from three of the canonical plasmids. Of the original acquired antibiotic resistance genes, this isolate only retained bla CTX-M-15, and as a result susceptibility to the carbapenems and amikacin was restored. Long-read sequencing of a subset of five representative isolates, collected between 2013 and 2017, allowed for the elucidation of the complex plasmid patterns and revealed the role of IS26-mediated plasmid reshuffling in the evolution of this clone. Such investigations of the mechanisms underlying plasmid stability, together with global and local surveillance programmes, are key to a better understanding of plasmid host range and dissemination.
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Maraki, Sofia, Viktoria Eirini Mavromanolaki, Dimitra Stafylaki, Evangelia Iliaki-Giannakoudaki, and Anna Kasimati. "Antimicrobial resistance trends among Klebsiella pneumoniae associated with urinary tract infections in Crete, Greece, 2017–2022." Acta Microbiologica et Immunologica Hungarica, May 22, 2024. http://dx.doi.org/10.1556/030.2024.02297.
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AbstractKlebsiella pneumoniae is one of the most prevalent bacteria causing urinary tract infections (UTIs). Its increasing resistance to a wide array of antibiotics limits available treatment options. This study investigated the characteristics and trends of antimicrobial resistance in K. pneumoniae isolated from UTIs in Crete, Greece, during 2017 and 2022. Among the 11,946 Enterobacteriaceae isolated from urine specimens, a total of 1,771 K. pneumoniae isolates were identified (14.8%), with an isolation frequency secondary to Escherichia coli (66.3%). K. pneumoniae isolates increased over the years, with a peak in the year 2022. Higher resistance rates were detected in ciprofloxacin (41%), trimethoprim/sulfamethoxazole (TMP/SMX) (38.1%) and nitrofurantoin (33.9%). Resistance to ciprofloxacin, amoxicillin/clavulanic acid, tigecycline, and TMP/SMX significantly increased from 33.7%, 24%, 6%, and 33.1%, respectively, over the years 2017–2019, to 47.8%, 34.2%, 14.3% and 42.8%, respectively, over the period 2020–2022. ESBL production and carbapenem resistance were decreased by 2.2% and 3.7%, respectively, over the two three-year periods (2017–2019 and 2020–2022). Among the 278 carbapenem-resistant K. pneumoniae (CRKP) isolates, 164 (59%), 66 (23.7%), 18 (6.5%) and 16 (5.8%) were positive for KPC, NDM, VIM and OXA-48 enzymes, respectively. Only 14 (5%) isolates harboured two carbapenemase genes, namely 10 (3.6%) both blaNDM and blaVIM, and 4 (1.4%) both blaKPC and blaNDM. Females, inpatients and the elderly were more frequently affected by CRKP. The frequency of multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were 32.6% and 7.7%, respectively. Continuous surveillance of local microbial prevalence and monitoring of antimicrobial resistance patterns provide critical information to guide the empiric therapy for UTIs and control the spread of MDR bacteria.