UNLABELLED Biocides, such as herbicides, are routinely tested for toxicity but not for sublethal effects on microbes. Many biocides are known to induce an adaptive multiple-antibiotic resistance phenotype. This can be due to either an increase in the expression of efflux pumps, a reduced synthesis of outer membrane porins, or both. Exposures of Escherichia coli and Salmonella enterica serovar T...

OBJECTIVES RamA regulates the AcrAB-TolC multidrug efflux system. Using Salmonella Typhimurium, we investigated the stability of RamA and its impact on antibiotic resistance. METHODS To detect RamA, we introduced ramA::3XFLAG::aph into plasmid pACYC184 and transformed this into Salmonella Typhimurium SL1344ramA::cat and lon::aph mutants. An N-terminus-deleted mutant [pACYC184ramA(Δ2-21)::3XFL...

OBJECTIVES To study the role of TolC and of parC mutation in high-level fluoroquinolone resistance in clonal clinical strains of Salmonella enterica serotype Typhimurium phage type DT204 (S. Typhimurium DT204). METHODS Deletion of the tolC gene (DeltatolC) was first performed in a susceptible S. Typhimurium DT104 strain lacking target gene mutations involved in fluoroquinolone resistance. P22...

Fluoroquinolone resistance is mainly caused by mutations in quinolone resistance-determining regions of DNA gyrase and topoisomerase IV in Escherichia coli. The AcrAB-TolC efflux pump contributes to resistance against fluoroquinolone and other antimicrobials. In this study, we investigated a high-level mechanism of fluoroquinolone resistance in E. coli that was isolated from human clinical samp...

background blood infections are an extensive range of disorders that can vary from limited bacteremia to fatal septicemia. bacteremia refers to the transient presence of a bacterium in the bloodstream. a delay in the diagnosis and treatment of sepsis can cause mortality, with a 20% - 50% prevalence rate. objectives due to the changing patterns of antibiotic resistance, as well as differences in...

background and objective: reports on mrsa strains are increasing worldwide. the aim of this study was to find the prevalence of mrsa strains isolated from clinical specimens and to evaluate their resistance profile. additionally we compared the phenotypic and genotypic methods for detection of methicillin resistance. materials and methods: in this cross-sectional study, a total of 41 isolates o...

Abstract: Antibiotic-resistant bacteria are spreading worldwide in medical settings but also in the environment. These resistant bacteria illustrate a major health problem in our times, and last-line antibiotics such as tigecycline represent an ultimate therapy option. Reports on tigecycline non-susceptible Enterobacteriaceae are presented with regard to medical settings but are rare with that ...

Fluoroquinolone resistance was characterized in Escherichia coli O78:K80 isolated from diseased turkeys. The level of resistance to fluoroquinolones of the isolates appeared closely correlated with substitutions in GyrA and ParC, but not with the production of the AcrAB efflux pump. Among isolates highly resistant to ciprofloxacin (MIC 8 mg/L) and harbouring identical substitutions (two in GyrA...