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Journal articles on the topic 'Beta lactam antibiotics – Synthesis'

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Published: 4 June 2021

Last updated: 13 February 2022

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1

Vondracek, Thomas G. "Beta-Lactam Antibiotics: Is Continuous Infusion The Preferred Method of Administration?" Annals of Pharmacotherapy 29, no. 4 (April 1995): 415–24. http://dx.doi.org/10.1177/106002809502900413.

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Objective: To examine the pharmacodynamic properties of the beta-lactam class of antibiotics and the rationale for their continuous infusion (CI), and to explore reasons that this mode of administration has not replaced intermittent infusion as the standard of practice. Data Sources: A MEDLINE search of the English-language literature evaluating CI administration of beta-lactam antibiotics was conducted. Bibliographic searches of these articles also were performed. Study Selection: Because there were few human trials, all available trials were considered for review. A cross section of clinical trials, animal studies, and in vitro studies examining the impact of the route of antibiotic administration was selected for each pharmacodynamic variable addressed. Data Synthesis: The support for CI as the preferred method of beta-lactam administration comes primarily from in vitro and animal data. Most beta-lactam antibiotics do not demonstrate concentration-dependent killing and have an appreciable postantibiotic effect only against gram-positive cocci. Their efficacy appears to be optimized by maintaining suprainhibitory concentrations throughout the dosing interval. Therefore, CI of beta-lactams could potentially enhance the efficacy of treatment or allow less drug to be used on a daily basis. This has yet to be demonstrated convincingly in human clinical trials. Comparative trials need to continue to explore die impact of the method of administration on patient outcomes such as duration and cost of therapy, as well as morbidity and mortality. Conclusions: Results of many animal and in vitro studies suggest that CI may be the optimal method of beta-lactam administration. Clinical trials need to further document the impact of the method of beta-lactam administration on the incidence of adverse effects, emergence of bacterial resistance, and patient outcome. Pharmacodynamic studies defining target beta-lactam concentrations, the practicality of CI in patients requiring multiple intravenous fluids and medications, and the pertinence of this issue when beta-lactam antibiotics are used as sole agents or in combination with other antimicrobials require further exploration.

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2

Filippova, A. A., M. Yu Rubtsova, M. M. Ulyashova, and N. K. Fursova. "Expression of beta-lactamase genes in multidrug-resistant bacteria." Bacteriology 5, no. 3 (2020): 34–46. http://dx.doi.org/10.20953/2500-1027-2020-3-34-46.

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Antimicrobial resistance is a global public health problem. In recent years, increasing of multi-drug resistant bacteria has been noted, which are resistant to different antimicrobial groups simultaneously, including beta-lactams. The main mechanism of anti-beta-lactam resistance in gram-negative bacteria is synthesis of various beta-lactamases that hydrolyze the antibiotics. The review is devoted to the analysis of data on the expression of beta-lactamase genes by multi-drug resistant bacteria and molecular genetic methods for their determination in RNA transcripts. Key words: antibiotic resistance, transcriptome, molecular genetic methods, beta-lactamases

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3

Mandel, Martin, Ludvík Novák, Miroslav Rajšner, Jiří Holubek, and Vladislava Holá. "New synthesis of oxime-type beta-lactam antibiotics." Collection of Czechoslovak Chemical Communications 54, no. 6 (1989): 1734–45. http://dx.doi.org/10.1135/cccc19891734.

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Reaction of anhydrous acids II with phosphorus pentachloride afforded hydrochlorides of chlorides III which were used in acylations of N,O-bis(trimethylsilyl) derivatives of 6-aminopenicillanic and 7-aminodeacetoxycephalosporanic acid. Change of the (Z)-configuration of the alkoxyimino group during the synthesis was observed only in the methoxyimino series. The prepared penicillins IV are effective against gram-positive as well as gram-negative bacteria.

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4

Salamone, Francine R. "Sulbactam/Ampicillin." Infection Control & Hospital Epidemiology 9, no. 7 (July 1988): 323–27. http://dx.doi.org/10.1086/645863.

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Sulbactam/ampicillin was recently marketed for use in several infections caused by beta-lactamase-producing organisms. Sulbactam is the second beta-lactamase inhibitor to become available in the United States. Interest in inhibition of beta-lactamases arose in the late 1960s when a combination consisting of an antibacterial agent and an enzyme inhibitor was found effective in the treatment of certain resistant gram-negative infections. It is now well accepted that the addition of a beta-lactamase inhibitor to a beta-lactam antibiotic may expand its usefulness in a variety of infections.The penicillin derivatives, known as beta-lactam antibiotics, possess a four-membered ring (beta-lactam ring) fused to a second ring (Figure). It is the beta-lactam ring that is essential for the inhibition of bacterial cell wall synthesis and subsequent bactericidal activity of these agents. The development of resistance to beta-lactam antibiotics may occur by a number of mechanisms, although the most important is bacterial production of enzymes (beta-lactamases) that are capable of beta-lactam ring hydrolysis and inactivation.Sulbactam resembles the penicillin derivatives in structure (Figure) and is able to preserve their activity by its ability to inhibit the action of beta-lactamases, particularly those of the Richmond classes II-V (gram-negative) and the group A beta-lactamases (gram-positive). Sulbactam is referred to as a “suicide inhibitor” because while forming an irreversible complex with the enzyme, it is destroyed in the process. By virtue of its ability to render the beta-lactamases inactive, sulbactam has been combined with ampicillin in an effort to restore its activity against a number of pathogens that have developed resistance by this mechanism.

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5

SKOTNICKI, JERAULD S., and BRUCE A. STEINBAUGH. "Synthesis and antibacterial activity of novel aminothiazolyl .BETA.-lactam derivatives." Journal of Antibiotics 39, no. 3 (1986): 372–79. http://dx.doi.org/10.7164/antibiotics.39.372.

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6

Miller, Marvin J. "Hydroxamate approach to the synthesis of .beta.-lactam antibiotics." Accounts of Chemical Research 19, no. 2 (February 1986): 49–56. http://dx.doi.org/10.1021/ar00122a004.

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7

ASZODI, J. "Design and synthesis of bridged $gamma;-lactams as analogues of $beta;-lactam antibiotics." Bioorganic & Medicinal Chemistry Letters 14, no. 10 (May 2004): 2489–92. http://dx.doi.org/10.1016/s0960-894x(04)00332-4.

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8

Burroughs, SF, and GJ Johnson. "Beta-lactam antibiotic-induced platelet dysfunction: evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin." Blood 75, no. 7 (April 1, 1990): 1473–80. http://dx.doi.org/10.1182/blood.v75.7.1473.1473.

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Abstract beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of [14C]-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with [3H]-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist [3H]-U46619 and antagonist [3H]-SQ29548, occurred. However, low- affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ([Ca2+]i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in [Ca2+]i. The loss of low- affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane.

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9

Burroughs, SF, and GJ Johnson. "Beta-lactam antibiotic-induced platelet dysfunction: evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin." Blood 75, no. 7 (April 1, 1990): 1473–80. http://dx.doi.org/10.1182/blood.v75.7.1473.bloodjournal7571473.

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beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of [14C]-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with [3H]-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist [3H]-U46619 and antagonist [3H]-SQ29548, occurred. However, low- affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ([Ca2+]i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in [Ca2+]i. The loss of low- affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane.

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10

KAWABATA, KOHJI, TAKASHI MASUGI, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. XII. Synthesis and activity of new 3-ethynylcephalosporin." Journal of Antibiotics 39, no. 3 (1986): 394–403. http://dx.doi.org/10.7164/antibiotics.39.394.

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11

AGÓCS, ATTILA, PÁL HERCZEGH, FERENC SZTARICSKAI, ZSUZSA GÁL, and FERENC HERNÁDI. "A Trimer of Phenoxymethyl Penicillin Sulphone: Synthesis of a New .BETA.-Lactam Podand." Journal of Antibiotics 55, no. 5 (2002): 524–27. http://dx.doi.org/10.7164/antibiotics.55.524.

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12

Bismara, Claudio, Romano Di Fabio, Daniele Donati, Tino Rossi, and Russell J. Thomas. "The synthesis of a key intermediate of tricyclic beta-lactam antibiotics." Tetrahedron Letters 36, no. 24 (June 1995): 4283–86. http://dx.doi.org/10.1016/0040-4039(95)00740-4.

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13

FURUKAWA, MINORU, MASAHIRO ARIMOTO, SHIGETAKE NAKAMURA, AKIO EJIMA, YOHKO HIGASHI, and HIROAKI TAGAWA. "Semisynthetic .BETA.-lactam antibiotics. I Synthesis and antibacterial activity of 7.BETA.-(2-aryl-2-(aminoacetamido)acetamido)cephalosporins." Journal of Antibiotics 39, no. 9 (1986): 1225–35. http://dx.doi.org/10.7164/antibiotics.39.1225.

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14

King, Dustin, and Natalie Strynadka. "Analysis of bacterial cell-wall synthesis to combat antibiotic resistance." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C701. http://dx.doi.org/10.1107/s2053273314092985.

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The peptidoglycan biosynthetic pathway is one of the most important processes in the bacterial cell to be exploited as a target for the design of antimicrobial drugs to combat infection and pathogenesis. This pathway, unique to bacteria, utilizes over twenty enzymes, likely in concert, with reactions that proceed from the cytoplasm, across the membrane and into the periplasmic space culminating in the production of the mesh-like structure composed of polymerized glycan and cross-linked peptide components that form the major structural component of the essential bacterial protective barrier known as the cell wall. Work in our group has aimed at understanding the structural and kinetic properties of several of these enzymes including the glycosyltransferase/transpeptidase activity of a family of enzymes known historically as the penicillin binding proteins (PBPs). As the name implies, these enzymes are also the target of beta-lactam antibiotics, and molecular modifications to transpeptidase variants have been shown to be linked to increased antibiotic resistance in superbugs such as Methicillin Resistant Staphlococcal aureus (MRSA). In parallel, highly disseminated plasmid-encoded beta-lactamase enzymes, with structural and mechanistic ties to the transpeptidases, have also arisen in many of the clinically important bacterial pathogens, leading to further widespread beta-lactam antibiotic resistance. The molecular details of these critical enzymatic reactions in bacterial viability and drug resistance will be presented.

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15

Kristich, Christopher J., Dušanka Djorić, and Jaime L. Little. "Genetic Basis for Vancomycin-Enhanced Cephalosporin Susceptibility in Vancomycin-Resistant Enterococci Revealed Using Counterselection with Dominant-Negative Thymidylate Synthase." Antimicrobial Agents and Chemotherapy 58, no. 3 (December 23, 2013): 1556–64. http://dx.doi.org/10.1128/aac.02001-13.

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ABSTRACTAntibiotic-resistant enterococci are major causes of hospital-acquired infections. All enterococci are intrinsically resistant to most cephalosporins, antibiotics in the beta-lactam family that impair peptidoglycan synthesis by inactivating the transpeptidases responsible for cross-linking. In addition, clinical isolates of enterococci often possess acquired resistance to vancomycin, a glycopeptide antibiotic that impairs peptidoglycan biosynthesis by a mechanism distinct from that of the beta-lactams, namely, by binding to thed-Ala-d-Ala termini found in peptidoglycan precursors to prevent their utilization by biosynthetic transglycosylases. Antimicrobial synergism between vancomycin and beta-lactams against vancomycin-resistant enterococci was originally described decades ago, but the genetic basis for synergy has remained unknown. Because a complete understanding of the mechanism underlying synergy between vancomycin and beta-lactams might suggest new targets or strategies for therapeutic intervention against antibiotic-resistant enterococci, we explored the genetic basis for synergy between vancomycin and cephalosporins inEnterococcus faecalis. To do so, we developed a counterselection strategy based on a dominant-negative mutant of thymidylate synthase and implemented this approach to create a panel of mutants in vancomycin-resistantE. faecalis. Our results confirm that vancomycin promotes synergy by inducing expression of thevanresistance genes, as a mutant in which thevangenes are expressed in the absence of vancomycin exhibits susceptibility to cephalosporins. Further, we show that peptidoglycan precursors substituted withd-Ala-d-Lac are not required for vancomycin-enhanced cephalosporin sensitivity. Instead, production of thed,d-carboxypeptidase VanYBis both necessary and sufficient to dramatically sensitizeE. faecalisto cephalosporins.

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16

Dörr, Tobias, Laura Alvarez, Fernanda Delgado, Brigid M. Davis, Felipe Cava, and Matthew K. Waldor. "A cell wall damage response mediated by a sensor kinase/response regulator pair enables beta-lactam tolerance." Proceedings of the National Academy of Sciences 113, no. 2 (December 28, 2015): 404–9. http://dx.doi.org/10.1073/pnas.1520333113.

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The bacterial cell wall is critical for maintenance of cell shape and survival. Following exposure to antibiotics that target enzymes required for cell wall synthesis, bacteria typically lyse. Although several cell envelope stress response systems have been well described, there is little knowledge of systems that modulate cell wall synthesis in response to cell wall damage, particularly in Gram-negative bacteria. Here we describe WigK/WigR, a histidine kinase/response regulator pair that enablesVibrio cholerae, the cholera pathogen, to survive exposure to antibiotics targeting cell wall synthesis in vitro and during infection. Unlike wild-typeV. cholerae, mutants lackingwigRfail to recover following exposure to cell-wall–acting antibiotics, and they exhibit a drastically increased cell diameter in the absence of such antibiotics. Conversely, overexpression ofwigRleads to cell slimming. Overexpression of activated WigR also results in increased expression of the full set of cell wall synthesis genes and to elevated cell wall content. WigKR-dependent expression of cell wall synthesis genes is induced by various cell-wall–acting antibiotics as well as by overexpression of an endogenous cell wall hydrolase. Thus, WigKR appears to monitor cell wall integrity and to enhance the capacity for increased cell wall production in response to damage. Taken together, these findings implicate WigKR as a regulator of cell wall synthesis that controls cell wall homeostasis in response to antibiotics and likely during normal growth as well.

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17

ARIMOTO, MASAHIRO, AKIO EJIMA, TOSHIFUMI WATANABE, HIROAKI TAGAWA, and MINORU FURUKAWA. "Semisynthetic .BETA.-lactam antibiotics. II Synthesis and antibacterial activity of 7.BETA.-(2-(acylamino)-2-(2-aminothiazol-4-yl)acetamido)cephalosporins." Journal of Antibiotics 39, no. 9 (1986): 1236–42. http://dx.doi.org/10.7164/antibiotics.39.1236.

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18

KAWABATA, KOHJI, HIDEAKI YAMANAKA, HISASHI TAKASUGI, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. XIII. Synthesis and structure-activity relationships of 7.BETA.-((Z)-2-aryl-2-carboxymethoxyiminoacetamido)-3-vinylcephalosporins." Journal of Antibiotics 39, no. 3 (1986): 404–14. http://dx.doi.org/10.7164/antibiotics.39.404.

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19

OHI, NOBUHIRO, BUNYA AOKI, TEIZO SHINOZAKI, KANZI MORO, TAKAO NOTO, TOSHIYUKI NEHASHI, HIROSHI OKAZAKI, and ISAO MATSUNAGA. "Semisynthetic .BETA.-lactam antibiotics. I. Synthesis and antibacterial activity of new ureidopenicillin derivatives having catechol moieties." Journal of Antibiotics 39, no. 2 (1986): 230–41. http://dx.doi.org/10.7164/antibiotics.39.230.

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20

BARRETT, DAVID, TAKESHI TERASAWA, SHINYA OKUDA, KOHJI KAWABATA, NOBUYOSHI YASUDA, TOSHIAKI KAMIMURA, KAZUO SAKANE, and TAKAO TAKAYA. "Studies on .BETA.-Lactam Antibiotics. Synthesis and Antibacterial Activity of Novel C-3 Alkyne-substituted Cephalosporins." Journal of Antibiotics 50, no. 1 (1997): 100–102. http://dx.doi.org/10.7164/antibiotics.50.100.

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21

ARIMOTO, MASAHIRO, TAKESHI HAYANO, TSUNEHIKO SOGA, TOSHIYUKI YOSHIOKA, HIROAKI TAGAWA, and MINORU FURUKAWA. "Semisynthetic .BETA.-lactam antibiotics. III Synthesis and antibacterial activity of 7.BETA.-(2-(2-aminothiazol-4-yl)-2-(substituted carbamoylmethoxyimino)acetamido)cephalosporins." Journal of Antibiotics 39, no. 9 (1986): 1243–56. http://dx.doi.org/10.7164/antibiotics.39.1243.

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22

YOSHIDA, Chosaku, Takako HORI, Kaishu MOMONOI, Kiyoshi TANAKA, Sumiko KISHIMOTO, and Isamu SAIKAWA. "Studies on monocyclic .BETA.-lactam antibiotics. Part I. Synthesis of 4-substituted monocyclic .BETA.-lactams by a lewis acid-mediated reaction." Agricultural and Biological Chemistry 50, no. 4 (1986): 839–46. http://dx.doi.org/10.1271/bbb1961.50.839.

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23

Lobkovsky, E., P. C. Moews, H. Liu, H. Zhao, J. M. Frere, and J. R. Knox. "Evolution of an enzyme activity: crystallographic structure at 2-A resolution of cephalosporinase from the ampC gene of Enterobacter cloacae P99 and comparison with a class A penicillinase." Proceedings of the National Academy of Sciences 90, no. 23 (December 1, 1993): 11257–61. http://dx.doi.org/10.1073/pnas.90.23.11257.

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The structure of the class C ampC beta-lactamase (cephalosporinase) from Enterobacter cloacae strain P99 has been established by x-ray crystallography to 2-A resolution and compared to a class A beta-lactamase (penicillinase) structure. The binding site for beta-lactam (penicillinase) structure. The binding site for beta-lactam antibiotics is generally more open than that in penicillinases, in agreement with the ability of the class C beta-lactamases to better bind third-generation cephalosporins. Four corresponding catalytic residues (Ser-64/70, Lys-67/73, Lys-315/234, and Tyr-150/Ser-130 in class C/A) lie in equivalent positions within 0.4 A. Significant differences in positions and accessibilities of Arg-349/244 may explain the inability of clavulanate-type inhibitors to effectively inactivate the class C beta-lactamases. Glu-166, required for deacylation of the beta-lactamoyl intermediate in class A penicillinases, has no counterpart in this cephalosporinase; the nearest candidate, Asp-217, is 10 A from the reactive Ser-64. A comparison of overall tertiary folding shows that the cephalosporinase, more than the penicillinase, is broadly similar to the ancestral beta-lactam-inhibited enzymes of bacterial cell wall synthesis. On this basis, it is proposed that the cephalosporinase is the older of the two beta-lactamases, and, therefore, that a local refolding in the active site, rather than a simple point mutation, was required for the primordial class C beta-lactamase to evolve to the class A beta-lactamase having an improved ability to catalyze the deacylation step of beta-lactam hydrolysis.

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24

KAWABATA, KOHJI, TAKASHI MASUGI, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. XI. Synthesis and structure-activity relationships of new 3-(2,2-dihalovinyl)cephalosporins." Journal of Antibiotics 39, no. 3 (1986): 384–93. http://dx.doi.org/10.7164/antibiotics.39.384.

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25

ARIMOTO, MASAHIRO, SHUICHI YOKOHAMA, MUTUMI SUDOU, YOSHIFUMI ICHIKAWA, TAKESHI HAYANO, HIROAKI TAGAWA, and MINORU FURUKAWA. "Semisynthetic .BETA.-lactam antibiotics. IV. Synthesis and antibacterial activity of 7.BETA.-(2-(hetero aromatic methoxyimino)-2-(2-aminothiazol-4-yl)acetamido)cephalosporins." Journal of Antibiotics 41, no. 12 (1988): 1795–811. http://dx.doi.org/10.7164/antibiotics.41.1795.

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26

Gardete, S., S. W. Wu, S. Gill, and A. Tomasz. "Role of VraSR in Antibiotic Resistance and Antibiotic-Induced Stress Response in Staphylococcus aureus." Antimicrobial Agents and Chemotherapy 50, no. 10 (October 2006): 3424–34. http://dx.doi.org/10.1128/aac.00356-06.

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ABSTRACT Exposure of Staphylococcus aureus to cell wall inhibitors induces massive overexpression of a number of genes, provided that the VraSR two-component sensory regulatory system is intact. Inactivation of vraS blocks this transcriptional response and also causes a drastic reduction in the levels of resistance to beta-lactam antibiotics and vancomycin. We used an experimental system in which the essential cell wall synthesis gene of S. aureus, pbpB, was put under the control of an isopropyl-β-d-thiogalactopyranoside-inducible promoter in order to induce reversible perturbations in cell wall synthesis without the use of any cell wall-active inhibitor. Changes in the level of transcription of pbpB were rapidly followed by parallel changes in the vraSR signal, and the abundance of the pbpB transcript was precisely mirrored by the abundance of the transcripts of vraSR and some additional genes that belong to the VraSR regulon. Beta-lactam resistance in S. aureus appears to involve a complex stress response in which VraSR performs the critical role of a sentinel system capable of sensing the perturbation of cell wall synthesis and allowing mobilization of genes that are essential for the generation of a highly resistant phenotype. One of the sites in cell wall synthesis “sensed” by the VraSR system appears to be a step catalyzed by PBP 2.

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27

YAMANAKA, HIDEAKI, TOSHIYUKI CHIBA, KOHJI KAWABATA, HISASHI TAKASUGI, TAKASHI MASUGI, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. IX. Synthesis and biological activity of a new orally active cephalosporin, cefixime (FK027)." Journal of Antibiotics 38, no. 12 (1985): 1738–51. http://dx.doi.org/10.7164/antibiotics.38.1738.

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28

LANG, M., P. SCHNEIDER, W. TOSCH, R. SCARTAZZINI, and O. ZAK. "The penems, a new class of .BETA.-lactam antibiotics. 7. Synthesis and antimicrobial activity of 2-heterocyclylmercaptoalkyl derivatives." Journal of Antibiotics 39, no. 4 (1986): 525–34. http://dx.doi.org/10.7164/antibiotics.39.525.

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29

YAMASHITA, HARUO, NOBUYOSHI MINAMI, KYOICHI SAKAKIBARA, SUSUMU KOBAYASHI, MASAJI OHNO, MASA HAMADA, and HAMAO UMEZAWA. "Monocyclic .BETA.-lactam antibiotics: Synthesis and antibacterial activity of 4-(substituted ethyl)-2-azetidinone-1-sulfonic acid derivatives." Journal of Antibiotics 40, no. 12 (1987): 1716–32. http://dx.doi.org/10.7164/antibiotics.40.1716.

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30

NAGANO, NORIAKI, Komi NAKANO, TADAO SHIBANUMA, YUKIYASU MURAKAMI, and RYUICHIRO HARA. "Studies on .BETA.-lactam antibiotics. I Synthesis and in vitro anti-pseudomonal activity of 3-isothiazole-cephalosporin derivatives." Journal of Antibiotics 40, no. 2 (1987): 173–81. http://dx.doi.org/10.7164/antibiotics.40.173.

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31

Ren, Xiao-Feng, and Edward Turos. "Synthesis of Novel .beta.-Lactam Core Structures Related to the Penam and Penem Antibiotics." Journal of Organic Chemistry 59, no. 20 (October 1994): 5858–61. http://dx.doi.org/10.1021/jo00099a007.

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32

Cho, Hongbaek, Tsuyoshi Uehara, and Thomas G. Bernhardt. "Beta-Lactam Antibiotics Induce a Lethal Malfunctioning of the Bacterial Cell Wall Synthesis Machinery." Cell 159, no. 6 (December 2014): 1300–1311. http://dx.doi.org/10.1016/j.cell.2014.11.017.

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33

Rodionov, D. G., and E. E. Ishiguro. "Effects of inhibitors of protein synthesis on lysis of Escherichia coli induced by beta-lactam antibiotics." Antimicrobial Agents and Chemotherapy 40, no. 4 (April 1996): 899–903. http://dx.doi.org/10.1128/aac.40.4.899.

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The role of protein synthesis in ampicillin-induced lysis of Escherichia coli was investigated. The inhibition of protein synthesis through amino acid deprivation resulted in the rapid development of ampicillin tolerance as a consequence of the stringent response, as previously reported. In contrast, inhibition of protein synthesis by use of ribosome inhibitors such as chloramphenicol did not readily confer ampicillin tolerance and, in fact, promoted the development of both stages of the ampicillin-induced lysis process, i.e., (i) an ampicillin-dependent stage which apparently involves the interaction of penicillin-binding proteins with ampicillin and (ii) an ampicillin-independent stage which may represent the events leading to the deregulation of peptidoglycan hydrolase activity. We propose that lysis was facilitated when protein synthesis was inhibited because the production of new penicillin-binding proteins to replace those which were ampicillin inhibited was prevented under these conditions.

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34

YAMANAKA, HIDEAKI, KOHJI KAWABATA, KENJI MIYAI, HISASHI TAKASUGI, TOSHIAKI KAMIMURA, YASUHIRO MINE, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. X. Synthesis and structure-activity relationships of 7.BETA.-((Z)-2-(2-amino-4-thiazolyl)-2-(carboymethoxyimino)acetamido)cephalosporin derivatives." Journal of Antibiotics 39, no. 1 (1986): 101–10. http://dx.doi.org/10.7164/antibiotics.39.101.

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YOSHIDA, CHOSAKU, TAKAKO HORI, KAISHU MOMONOI, KATSUYUKI NAGUMO, JOJI NAKANO, TETSUMI KITANI, YOSHIKAZU FUKUOKA, and ISAMU SAIKAWA. "Studies on monocyclic .BETA.-lactam antibiotics. II. Synthesis and antibacterial activity of 3-acylamino-2-azetidinone-1-oxysulfonic acids." Journal of Antibiotics 38, no. 11 (1985): 1536–49. http://dx.doi.org/10.7164/antibiotics.38.1536.

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YOSHIDA, CHOSAKU, KIYOSHI TANAKA, JOJI NAKANO, YOZO TODD, TETSUO YAMAFUJI, RIKIZO HATTORI, YOSHIKAZU FUKUOKA, and ISAMU SAIKAWA. "Studies on monocyclic .BETA.-lactam antibiotics. III. Synthesis and antibacterial activity of N-(aromatic heterocyclic substituted)azetidin-2-ones." Journal of Antibiotics 39, no. 1 (1986): 76–89. http://dx.doi.org/10.7164/antibiotics.39.76.

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HARA, RYUICHIRO, EI-ICHI NAKAI, HIROYUKI HISAMICHI, and NORIAKI NAGANO. "Studies on .BETA.-lactam antibiotics. IV. An improved synthesis of 3-(isothiazolylythiomethyl)cephalosporins and its application to new derivatives." Journal of Antibiotics 47, no. 4 (1994): 477–86. http://dx.doi.org/10.7164/antibiotics.47.477.

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Torii, Sigeru, and Hideo Tanaka. "A New Strategic Intermediate for .BETA.-Lactam Antibiotic Synthesis: Allenecarboxylates." Journal of Synthetic Organic Chemistry, Japan 54, no. 11 (1996): 941–52. http://dx.doi.org/10.5059/yukigoseikyokaishi.54.941.

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39

Stetsko, T. I. "ANTIBIOTIC RESISTANCE OF BACTERIA OF THE FAMILY PASTEURELLACEAE, PATHOGENS OF RESPIRATORY INFECTIONS OF CATTLE AND PIGS." Scientific and Technical Bulletin оf State Scientific Research Control Institute of Veterinary Medical Products and Fodder Additives аnd Institute of Animal Biology 22, no. 1 (March 29, 2021): 197–208. http://dx.doi.org/10.36359/scivp.2021-22-1.24.

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In the article a literature review of scientific papers on the topic of antimicrobial resistance of bacteria of the family Pasteurellaceae, pathogens of respiratory diseases in pigs and cattle, is presented. The main mechanisms of the development of Pasteurellaceae resistance to β-lactam antibiotics are the synthesis of β-lactamases by bacteria, what are able to break the beta-lactam ring, thereby inactivating β-lactams, or alteration of the penicillin-binding proteins structure. Other mechanisms, such as reduced permeability of the outer membrane or the process of active removal of antibiotics from the bacterial cell (efflux), are very rare. Resistance among Pasteurellaceae to β-lactams is often associated with plasmids. Eflux and ribosomal protection are the main mechanisms for the development of resistance of Pasteurellaceae to tetracyclines. At least nine tetracycline resistance genes (tet genes) have been identified in bacteria of the genus Pasteurella, Mannheimia, Actinobacillus and Haemophilus, what encode these processes. Resistance to aminoglycosides and aminocyclitols is mainly caused by enzymatic inactivation of antibiotics, as well as through mutations in chromosomal genes. Many plasmids carry genes of resistance to aminoglycosides, causing resistance to antibiotics of other groups. Chemical modification of a ribosomal target by rRNA methylases and mutations in ribosomal proteins are the main resistance mechanisms of bacteria of the family Pasteurellaceae to macrolides. Many gram-negative bacteria have a natural resistance to macrolide antibiotics. The development of lincosamide resistance is influenced by methyltransferase 23S rRNA, active efflux proteins, enzymatic inactivation and chromosomal mutations. Resistance of bacteria of the family Pasteurellaceae to chloramphenicol is caused mainly by enzymatic inactivation, while the emergence of resistance to fluorophenicol is associated with the efflux of an antibiotic from a bacterial cell. Plasmids carrying phenicol resistance genes were detected in isolates of P. multocida, M. haemolytica, A. pleuropneumoniae and H. parasuis. Usually the level of bacteria sensitivity of the genus Pasteurella, Mannheimia, Actinobacillus and Haemophilus to quinolones is quite high. Resistance to quinolones mainly occurs due to mutational alterations in chromosomal genes, and may also be in consequence of the export antibiotics from the cell by membrane proteins or thanks to qnr genes of plasmids. The main mechanism of resistance to sulfonamides and trimethoprim is both plasmid-mediated and mutation-induced production of altered dihydropteroate synthetase and dihydrofolate reductase with reduced affinity with these antimicrobials. Monitoring of antibiotic resistance with the determination of its mechanism phenomenon will facilitate the choice of an effective agent of etiotropic therapy of respiratory diseases of cattle and pigs caused by bacteria of the family Pasteurellaceae.

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Talbot, M. K., F. Schaefer, V. Brocks, and J. G. Christenson. "Reactivation of peptidoglycan synthesis in ether-permeabilized Escherichia coli after inhibition by beta-lactam antibiotics." Antimicrobial Agents and Chemotherapy 33, no. 12 (December 1, 1989): 2101–8. http://dx.doi.org/10.1128/aac.33.12.2101.

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SOUTHGATE, R., C. BRANCH, S. COULTON, and E. HUNT. "ChemInform Abstract: Chemistry and Synthesis of Some Novel β-Lactam Antibiotics and . beta.-Lactamase Inhibitors." ChemInform 25, no. 31 (August 19, 2010): no. http://dx.doi.org/10.1002/chin.199431306.

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KITA, Yasuyuki, Norio SHIBATA, Osamu TAMURA, and Takashi MIKI. "Chemistry of O-Silylated Ketene Acetals: A Mild and Convenient Synthesis of .BETA.-Lactam Antibiotics." CHEMICAL & PHARMACEUTICAL BULLETIN 39, no. 9 (1991): 2225–32. http://dx.doi.org/10.1248/cpb.39.2225.

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Niu, Hongxia, Rebecca Yee, Peng Cui, Shuo Zhang, Lili Tian, Wanliang Shi, David Sullivan, Bingdong Zhu, Wenhong Zhang, and Ying Zhang. "Identification and Ranking of Clinical Compounds with Activity Against Log-phase Growing Uropathogenic Escherichia coli." Current Drug Discovery Technologies 17, no. 2 (June 19, 2020): 191–96. http://dx.doi.org/10.2174/1570163815666180808115501.

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Background: Uropathogenic Escherichia coli (UPEC) is a major cause of Urinary Tract Infections (UTIs). Due to increasing antibiotic-resistance among UPEC bacteria, new treatment options for UTIs are urgently needed. Objective: To identify new agents targeting growing bacteria that may be used for the treatment of antibiotic-resistant UTIs. Methods: We screened a clinical compound library consisting of 1,524 compounds using a high throughput 96-well plate assay and ranked the activities of the selected agents according to their MICs against the UPEC strain UTI89. Results: We identified 33 antibiotics which were active against log-phase clinical UPEC strain UTI89. Among the selected antibiotics, there were 12 fluoroquinolone antibiotics (tosufloxacin, levofloxacin, sparfloxacin, clinafloxacin, pazufloxacin, gatifloxacin, enrofloxacin, lomefloxacin, norfloxacin, fleroxacin, flumequine, ciprofloxacin), 15 beta-lactam or cephalosporin antibiotics (cefmenoxime, cefotaxime, ceftizoxime, cefotiam, cefdinir, cefoperazone, cefpiramide, cefamandole, cefixime, ceftibuten, cefmetazole, cephalosporin C, aztreonam, piperacillintazobactam, mezlocillin), 3 tetracycline antibiotics (meclocycline, doxycycline, tetracycline), 2 membrane-acting agents (colistin and clofoctol), and 1 protein synthesis inhibitor (amikacin). Among them, the top 7 hits were colistin, tosufloxacin, levofloxacin, sparfloxacin, clinafloxacin, cefmenoxime and pazufloxacin, where clinafloxacin and pazufloxacin were the newly identified agents active against UPEC strain UTI89. We validated the key results obtained with UTI89 on two other UTI strains CFT073 and KTE181 and found that they all had comparable MICs for fluoroquinolones while CFT073 and KTE181 were more susceptible to cephalosporin antibiotics and tetracycline antibiotics but were less susceptible to colistin than UTI89. Conclusion: Our findings provide possible effective drug candidates for the more effective treatment of antibiotic-resistant UTIs.

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Alkema, Wynand B. L., Erik de Vries, Rene Floris, and Dick B. Janssen. "Kinetics of enzyme acylation and deacylation in the penicillin acylase-catalyzed synthesis of beta-lactam antibiotics." European Journal of Biochemistry 270, no. 18 (September 2003): 3675–83. http://dx.doi.org/10.1046/j.1432-1033.2003.03728.x.

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45

KAWABATA, KOHJI, KENJI MIYAI, HISASHI TAKASUGI, and TAKAO TAKAYA. "Studies on .BETA.-lactam antibiotics. XIV Synthesis and biological activity of the (E)-isomer of FK027." CHEMICAL & PHARMACEUTICAL BULLETIN 34, no. 8 (1986): 3458–64. http://dx.doi.org/10.1248/cpb.34.3458.

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46

Lim, H. M., R. K. Iyer, and J. J. Pène. "Site-directed mutagenesis of dicarboxylic acids near the active site of Bacillus cereus 5/B/6 β-lactamase II." Biochemical Journal 276, no. 2 (June 1, 1991): 401–4. http://dx.doi.org/10.1042/bj2760401.

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An amino acid residue functioning as a general base has been proposed to assist in the hydrolysis of beta-lactam antibiotics by the zinc-containing Bacillus cereus beta-lactamase II [Bicknell & Waley (1985) Biochemistry 24, 6876-6887]. Oligonucleotide-directed mutagenesis of cloned Bacillus cereus 5/B/6 beta-lactamase II was used in an ‘in vivo’ study to investigate the role of carboxy-group-containing amino acids near the active site of the enzyme. Substitution of asparagine for the wild-type aspartic acid residue at position 81 resulted in fully functional enzyme. An aspartic acid residue at position 90 is essential for beta-lactamase II to confer any detectable ampicillin and cephalosporin C resistance to Escherichia coli. Conversion of Asp90 into Asn90 or Glu90 lead to the synthesis of inactive enzyme, suggesting that the spatial position of the beta-carboxy group of Asp90 is critical for enzyme function.

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NAGANO, NORIAKI, KOHJI NAKANO, TADAO SHIBANUMA, and RYUICHIRO HARA. "Studies on .BETA.-lactam antibiotics. II. Synthesis and antibacterial activity of cephalosporins with substituted 1,3-dithietane directly attached to the C-3 position." Journal of Antibiotics 44, no. 4 (1991): 415–21. http://dx.doi.org/10.7164/antibiotics.44.415.

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48

Aiswarya P. Nath, Arul Balasubramanian, and Kothai Ramalingam. "Cephalosporins : An imperative antibiotic over the generations." International Journal of Research in Pharmaceutical Sciences 11, no. 1 (January 20, 2020): 623–29. http://dx.doi.org/10.26452/ijrps.v11i1.1866.

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Cephalosporins are the most commonly prescribed class of antibiotics, and its structure and pharmacology are similar to that of penicillin. It's a bactericidal, and its structure contains beta-lactam ring, as like of penicillin, which intervenes in bacterial cell wall synthesis. Cephalosporins are derived from the mold Acremonium (previously called as Cephalosporium). It was first discovered in 1945; scientists have been improving the structure of cephalosporins to make it more effective against a wider range of bacteria. Whenever the structure of cephalosporins modified, a new "generation" of cephalosporins are made. So far, there are five generations of cephalosporins available. They are prescribed against various organisms and infections. The cephalosporin antibiotics interfere with cell-wall synthesis of bacteria, leading to the breakdown of the infectious organism. To achieve this effect, the antibiotic must cross the bacterial cell wall and bind to the penicillin-binding proteins. Various generations of cephalosporins, mechanisms of resistance, pharmacokinetics, adverse reactions, and their clinical use were reviewed in this article. Most of the cephalosporins are available as parenteral, but the oral formulations are also available for certain drugs. Rather than learn all cephalosporins, it is reasonable for the clinician to be familiar with selected cephalosporins among the parenteral and oral formulations.

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Shcherbinin, D. S., M. Yu Rubtsova, V. G. Grigorenko, I. V. Uporov, A. V. Veselovsky, and A. M. Egorov. "Investigation the role of mutations M182T and Q39K in structure of beta-lactamase TEM-72 by molecular dynamics method." Biomeditsinskaya Khimiya 62, no. 5 (2016): 527–34. http://dx.doi.org/10.18097/pbmc20166205527.

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Synthesis of b-lactamases is one of the common mechanisms of bacterial resistance to b-lactam antibiotics including penicillins and cephalosporins. The widespread use of antibiotics results in appearance of numerous extended-spectrum b-lactamase variants or resistance to inhibitors. Mutations of 92 residues of TEM type were found. Several mutations are the key mutations that determine the extension of spectrum of substrates. However, roles of the most associated mutations, located far from active site, remain unknown. We have investigated the role of associated mutations in structure of b-lactamase TEM-72, which contain two key mutation (G238S, E240K) and two associated mutations (Q39K, M182T) by means of simulation of molecular dynamics. The key mutation lead to destabilization of the protein globule, characterized by increased mobility of amino acid residues at high temperature of modelling. Mutation M182T lead to stabilization protein, whereas mutation Q39K is destabilizing mutation. It seems that the last mutation serves for optimization of conformational mobility of b-lactamase and may influence on enzyme activity.

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Lee, E. H., E. Collatz, I. Podglajen, and L. Gutmann. "A rob-like gene of Enterobacter cloacae affecting porin synthesis and susceptibility to multiple antibiotics." Antimicrobial Agents and Chemotherapy 40, no. 9 (September 1996): 2029–33. http://dx.doi.org/10.1128/aac.40.9.2029.

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A chromosomal gene of Enterobacter cloacae affecting the synthesis of major outer membrane proteins in E. cloacae and Escherichia coli was cloned by using selection for resistance to cefoxitin in E. coli. The presence of the gene, when plasmid-borne, led to a decrease in the amount of porin F in E. cloacae and the amount of OmpF in E. coli and caused 2- to 32-fold increases in the MICs of chloramphenicol, tetracycline, quinolones, and beta-lactam antibiotics. The gene encoded a 33-kDa protein, similar (83% identity) to the protein Rob involved in the initiation of DNA replication in E. coli, which was called RobA(EC1) by analogy. RobA from E. cloacae was found to inhibit ompF expression at the posttranscriptional level via activation of micF, a gene also apparently present in E. cloacae, as detected by PCR. As with its homolog from E. coli, RobA(EC1) is related to the XylS-AraC class of positive transcriptional regulators, along with MarA and SoxS, which also cause a micF-mediated decrease in the level of ampF expression.

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