Penicillins and cephalosporins

Krimpen, P. C. van; Bennekom, W.P. van; Bult, A.

doi:10.1007/bf01956487

Cited by 26 publications

(8 citation statements)

References 173 publications

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“…Interestingly, despite the dramatic increase in ceftriaxone resistance in the epa mutants, there was little or no difference in MICs for the other ␤-lactam antibiotics tested. Cephalosporins and penicillins have a similar mechanism of action and a core ␤-lactam ring, but the feature differences are in the type and number of R-group side chains which lead to differences in physical, chemical, and biochemical properties (32). Since the mechanism behind the increased ceftriaxone resistance in the epa mutants is currently unknown, it is difficult to say why there is a difference across the ␤-lactam antibiotics tested; however, our observation of increased cephalosporin resistance in epa mutants warrants further investigation.…”

Section: Discussionmentioning

confidence: 99%

Role of epaQ , a Previously Uncharacterized Enterococcus faecalis Gene, in Biofilm Development and Antimicrobial Resistance

2019

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Enterococcus faecalis is a commensal of the human gastrointestinal tract; it is also an opportunistic pathogen and one of the leading causes of hospital-acquired infections. E. faecalis produces biofilms that are highly resistant to antibiotics, and it has been previously reported that certain genes of the epa operon contribute to biofilm-associated antibiotic resistance. Despite several studies examining the epa operon, many gene products of this operon remain annotated as hypothetical proteins. Here, we further explore the epa operon; we identified epaQ, currently annotated as encoding a hypothetical membrane protein, as being important for biofilm formation in the presence of the antibiotic daptomycin. Mutants with disruptions of epaQ were more susceptible to daptomycin relative to the wild type, suggesting its importance in biofilm-associated antibiotic resistance. Furthermore, the ΔepaQ mutant exhibited an altered biofilm architectural arrangement and formed small aggregates in liquid cultures. Our cumulative data show that epa mutations result in altered polysaccharide content, increased cell surface hydrophobicity, and decreased membrane potential. Surprisingly, several epa mutations significantly increased resistance to the antibiotic ceftriaxone, indicating that the way in which the epa operon impacts antibiotic resistance is antibiotic dependent. These results further define the key role of epa in antibiotic resistance in biofilms and in biofilm architecture. IMPORTANCE E. faecalis is a common cause of nosocomial infection, has a high level of antibiotic resistance, and forms robust biofilms. Biofilm formation is associated with increased antibiotic resistance. Therefore, a thorough understanding of biofilm-associated antibiotic resistance is important for combating resistance. Several genes from the epa operon have previously been implicated in biofilm-associated antibiotic resistance, pathogenesis, and competitive fitness in the GI tract, but most genes in this locus remain uncharacterized. Here, we examine epaQ, which has not been characterized functionally. We show that the ΔepaQ mutant exhibits reduced biofilm formation in the presence of daptomycin, altered biofilm architecture, and increased resistance to ceftriaxone, further expanding our understanding of the contribution of this operon to intrinsic enterococcal antibiotic resistance and biofilm growth.

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Section: Discussionmentioning

confidence: 99%

Role of epaQ , a Previously Uncharacterized Enterococcus faecalis Gene, in Biofilm Development and Antimicrobial Resistance

2019

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“…Although consumption of penicillins was relatively high in both hospital and nursing home (not shown), these antimicrobials could not be measured in any of the wastewater samples, because of their chemical instability [33]. Tetracycline was not used in the hospital, but still it was found at low concentrations in hospital wastewater (six samples) (Table S2).…”

Section: Resultsmentioning

confidence: 99%

Abundance and Antimicrobial Resistance of Three Bacterial Species along a Complete Wastewater Pathway

Verburg

García-Cobos

Leal³

et al. 2019

Microorganisms

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After consumption, antibiotic residues and exposed bacteria end up via the feces in wastewater, and therefore wastewater is believed to play an important role in the spread of antimicrobial resistance (AMR). We investigated the abundance and AMR profiles of three different species over a complete wastewater pathway during a one-year sampling campaign, as well as including antimicrobial consumption and antimicrobial concentrations analysis. A total of 2886 isolates (997 Escherichia coli, 863 Klebsiella spp., and 1026 Aeromonas spp.) were cultured from the 211 samples collected. The bacterial AMR profiles mirrored the antimicrobial consumption in the respective locations, which were highest in the hospital. However, the contribution of hospital wastewater to AMR found in the wastewater treatment plant (WWTP) was below 10% for all antimicrobials tested. We found high concentrations (7–8 logs CFU/L) of the three bacterial species in all wastewaters, and they survived the wastewater treatment (effluent concentrations were around 5 log CFU/L), showing an increase of E. coli in the receiving river after the WWTP discharge. Although the WWTP had no effect on the proportion of AMR, bacterial species and antimicrobial residues were still measured in the effluent, showing the role of wastewater contamination in the environmental surface water.

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“…Penicillin is a β-lactam antibiotic commonly used clinically for the treatment of Gram-positive bacterial infection, such as Staphylococcus and Streptococcus. Its pharmacological effect involves destroying the bacterial cell wall, thereby killing bacteria (11)(12)(13). Streptomycin is an aminoglycoside antibiotic, and its mechanism of action is to act on ribosomes in bacteria, inhibit bacterial protein synthesis, and destroy the integrity of bacterial cell membranes.…”

Section: Introductionmentioning

confidence: 99%

Construction of a model of endometritis in domestic rabbits using equine-derived pathogens and evaluation of therapeutic effect of sensitive drugs

Ding

Xiao²,

Shi³

et al. 2023

Front. Vet. Sci.

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Pathogenic bacteria were isolated from the uterine lavage fluid of a mare with endometritis. After identification and purification, the pathogenic bacteria were injected into the uterus of rabbits to induce endometritis. Then, anatomical, blood routine, chemical examination, and histopathological examinations were performed on the rabbits. Rabbit uterus was collected, and quantitative polymerase chain reaction (qPCR) was used to detect the mRNA expression of inflammatory factors including IL-1β, IL-6, and TNF-α in the rabbit uterus. In addition, enzyme-linked immunosorbent assay (ELISA) was used to detect the uterine concentrations of the inflammatory factors IL-1β, IL-6, and TNF-α. Western Blot was used to detect the protein expressions of NF-kB, IkBα, and TNF-α in the NF-kB pathway. An antibiotic treatment group was also set up to verify the accuracy of the results. The clinical examination results showed that there was a significant increase of leukocytes in the blood of the rabbits in the model group (P < 0.01). The uterus was congested, enlarged, and purulent. The integrity of the uterine lining was destroyed, and there was a significant increase of lymphocytes in the uterus (P < 0.01). The qPCR and ELISA results showed that the expressions of the inflammatory factors IL-1β, IL-6, and TNF-α in the uterus of rabbits were significantly increased (P < 0.01). Western blot results showed that the inflammatory factors IL-1β, IL-6, and TNF-α play a role in promoting inflammation through the NF-kB pathway. The results of the test provide a simple, economical, and reliable means of studying the occurrence, development, prevention, and treatment of equine endometritis.

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Penicillins and cephalosporins

Cited by 26 publications

References 173 publications

Role of epaQ , a Previously Uncharacterized Enterococcus faecalis Gene, in Biofilm Development and Antimicrobial Resistance

Role of epaQ , a Previously Uncharacterized Enterococcus faecalis Gene, in Biofilm Development and Antimicrobial Resistance

Abundance and Antimicrobial Resistance of Three Bacterial Species along a Complete Wastewater Pathway

Construction of a model of endometritis in domestic rabbits using equine-derived pathogens and evaluation of therapeutic effect of sensitive drugs

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