Search

Background/aim: Nonsteroidal antiinflammatory drugs (NSAIDs) including diclofenac, naproxen, ibuprofen, acetylsalicylic acid, and acetaminophen have been shown to have antimicrobial effects on various microorganisms. The aim of this study was to investigate the antibacterial effects of NSAIDs on Staphylococcus aureus., Materials and Methods: Susceptibilities of S. aureus strains to NSAIDs with or without antimicrobials (moxifloxacin, vancomycin, ciprofloxacin, clindamycin, and gentamicin) were determined using the microdilution method and disk diffusion test. Expression levels of genes in the presence of drugs were investigated by real-time quantitative RT-PCR (qRT-PCR), and immunoblotting analysis was performed for staphylococcal protein A (SpA)., Results: Our results showed that all NSAIDs were active against S. aureus strains with MIC values ranging from 195 μg/mL to 6250 μg/ mL. NSAIDs increased the antibiotic susceptibility of the strains, and diclofenac was found to be more effective than the other drugs. Drugs showed different effects on expression levels of virulence factor and/or regulatory genes. Immunoblotting analysis of SpA protein was mostly in accordance with qRT-PCR results., Conclusion: The regulatory/virulence factor genes and proteins of S. aureus investigated in this study may be reasonable targets for these drugs, and we suggest that the data may contribute to the field of infection control and antimicrobial resistance., Competing Interests: none declared., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

Background: Via its virulence factors such as swarm differentiation, biofilm and hemolysin production, urease enzyme, Proteus mirabilis causes urinary tract infections (UTIs), especially in complicated cases. Anti-pathogenic compounds attenuate the virulence of bacteria without showing 'cidal' activity and carry the potential to be used in the prevention and treatment of infectious diseases., Purpose: Search for anti-pathogenic effects of quercetin, which is a widely known and biologically active phytochemical, on Proteus mirabilis was the purpose of this study. In this context, the potential inhibitory activity of quercetin on swarming motility and biofilm production of a wild-type strain, P. mirabilis HI4320, was investigated in both phenotypically and genotypically., Methods: Quercetin's effect on swarming motility was examined on LB agar plates, containing quercetin at various concentrations, by measuring the swarming diameter. The effect on biofilm formation, on the other hand, was analyzed by staining the formed biofilm of the bacterium, exposed to quercetin at various concentrations, with crystal violet and reading spectrophotometrically. Differences in expression levels of selected genes involved in swarming regulation were determined by real-time reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) to evaluate the mechanism of inhibitory action on swarming. Further investigations were carried out repeating swarming assays with the clones that derived from the wild-type strain by a TA system kit for direct one-step cloning and overexpressing the relevant genes., Results: Our study revealed that quercetin inhibited swarming motility while activating biofilm production of P. mirabilis in direct proportion to the dose. Although all selected genes are inhibited in the same manner in liquid medium, and no significant differences could be detected in solid medium as demonstrated by RT-qPCR, experiments repeated with the clones overexpressing flhC (a component of flagellar transcriptional activator), speB (an agmatinase enzyme) and ompF (an outer membrane porin) genes showed that the respective clones could restore swarming, compensating for the inhibitory effect of quercetin., Conclusion: Quercetin's inhibitory effect on P. mirabilis swarming was possibly due to interactions with components of swarming regulators, the genes expressing polyamine coding enzymes that trigger swarm differentiation, or active pump proteins., (Copyright © 2018. Published by Elsevier GmbH.)

Introduction: Increased tuberculosis prevalence, and isolation of multidrug resistant (MDR) Mycobacterium tuberculosis strains frequently as causative organisms from tuberculosis infections are resulted in increasing need of new anti-tuberculosis drugs. Nowadays, fluoroquinolones known to have fewer side effects than the other drugs used in treatment of tuberculosis are sometimes assessed even as first-line anti-tuberculosis drugs due to their in vitro and in vivo strong activity. It was aimed in this study to investigate phenotypically the fluoroquinolone susceptibility in MDR and non-MDR M. tuberculosis isolates., Materials and Methods: A total of 126 MDR and non-MDR M. tuberculosis isolates from mycobacteriology laboratory of two hospitals in the Aegean Region of Turkey were included in the study. Ciprofloxacin (CIP), levofloxacin (LEV) and moxifloxacin (MXF) susceptibilities were assessed by agar proportion method according to the Clinical and Laboratory Standards Institute (CLSI) recommendations., Result: Twelve (15.2%), 5 (6.3%) and 4 (5.1%) of the MDR M. tuberculosis strains were resistant to CIP, LEV, MXF, respectively [resistance breakpoints (µg/mL); CIP (> 2), LEV (> 1), MXF (> 0.5)] while non-MDR strains were susceptible to CIP, LEV, MXF., Conclusions: Consequently, although high fluoroquinolone susceptibilities were evaluated as a pleasing data in this study, to preserve their efficiency for many years steadily, quinolone usage and resistance increment in MDR M. tuberculosis isolates should be monitored elaborately.

In this study, we examined the prevalence of the PER-1 enzyme and the presence of clinically important integron classes in ceftazidime-resistant Gram-negative bacteria isolated at a university hospital. The blaPER-1 gene was detected by PCR in 33 (19.5%) of the total 169 Gram-negative bacteria, including 17 (23.3%) of the 73 Pseudomonas aeruginosa isolates and 16 (25%) of the 64 Acinetobacter baumannii complex isolates. Molecular fingerprinting revealed that blaPER-1 prevalence was mostly due to the dissemination of clonally related P. aeruginosa and A. baumannii complex strains. Class 1 integron (intI1) was detected in 52.7% of the 169 bacteria examined in this study. Its detection rates were estimated at 49.3% and 57.8% of the P. aeruginosa and A. baumannii complex strains isolated, respectively. It was also detected in 11 of the 16 Escherichia coli isolates and 5 of the 10 Klebsiella pneumoniae isolates. A single E. coli isolate and another K. pneumoniae isolate contained both class 1 and class 2 integrase genes. The results of this study revealed that clonally related blaPER-1-positive P. aeruginosa and A. baumannii complex strains, mostly harboring intI1, had disseminated at our hospital.