ABSTRACT
Aims: To investigate plasmid‑mediated quinolone resistance in clinical isolates of Pseudomonas aeruginosa with the polymerase chain reaction (PCR). The plasmid‑mediated quinolone resistance genes have been identified in many bacteria within the Enterobactericeae family, they have not been detected in P. aeruginosa isolates. Subjects and Methods: Identification of the isolates and testing of antibiotic susceptibility was performed in Vitek2 Compact (Biomeriux, France) and Phoinex (BD, USA) automated systems. Screening for the qnrA, qnrB, qnrS, qnrC, aac (6′)‑Ib‑cr and qepA genes was carried out by PCR amplification and aac (6′)‑Ib‑cr DNA sequencing. Results: The qnr and the qepA genes were not detected in any of P. aeruginosa isolates. The aac (6’)‑Ib gene was detected in six of the isolates and positive isolates for aac (6’)‑Ib were sequenced for detection of the aac (6’)‑Ib‑cr variant but aac (6’)‑Ib‑cr was not detected in any isolates. Conclusions: Plasmid‑mediated quinolone resistance genes have so far not been identified in P. aeruginosa isolates. However, qnrB have detected in P. florescens and P. putida isolates. This is the first study conducted on the qnrA, qnrB, qnrS and qnrC genes as well as the qepA and aac (6’)‑Ib‑cr genes in P. aeruginosa clinical isolates.
ABSTRACT
Purpose: Several genes encoding different cytokines and human leucocyte antigens (HLA) may play crucial roles in host susceptibility to tuberculosis (TB). Our objective was to investigate whether these genes might be associated with protection from or susceptibility to TB. Materials and Methods: Genomic DNA from patients with TB (n = 30) and ethnically matched controls (n = 30) was genotyped by using sequence-specific primers-polymerase chain reaction and sequence-specific oligonucletid methods. Results: Our results demonstrated that HLA-Cw*01 [P = 0.05, odds ration (OR) (95% confidence interval) = 2.269 (1.702-3.027)] allele frequency was significantly more common in TB patients than in healthy controls, and HLA-Cw*01 may be associated with susceptibility to TB. Analysis of cytokine allele frequencies showed that interleukin (IL)-10, -819 C and -592 C alleles was significantly more common in TB patients than in controls (pc: 0.038 and 0.017, respectively). From the IL-10 cluster, a positive significant difference was found at positions -1082 and -592 C/C (pc: 0.027 and 0.054, respectively) genotypes. Although these differences could be explained by the highest frequency of C/C and G/G homozygous patients with TB, in contrast to the control group, statistically significant differences for the C/C genotype however were lost after Bonferroni correction of the P-values. Conclusion: Altogether, our results suggest that the polymorphisms in HLA (class I) and cytokine (IL-10) genes may affect the susceptibility to TB and increase the risk of developing the disease.
Subject(s)
Cytokines/genetics , DNA Primers/genetics , Disease Susceptibility , Female , Gene Frequency , Genotype , HLA Antigens/genetics , Humans , Male , Polymerase Chain Reaction/methods , Polymorphism, Genetic , Tuberculosis/genetics , Tuberculosis/immunologyABSTRACT
In this study, in vitro activity of tigecycline (TIG) and ertapenem (ERT) against clinical isolates of Brucella melitensis and the effect of different media on in vitro test results were investigated. The in vitro effects of TIG and ERT to 38 B. melitensis isolates were comparatively investigated in brucella agar and 5% sheep blood agar. MIC value of ERT was 0.032 μg/mL in 23 of 38 and 20 of 38 isolates on blood and brucella agar, respectively. Minimum inhibitory concentration values of TIG were substantially different ranging between 0.064-0.25 μg/mL on blood agar. However, MIC values of TIG were similar on brucella agar with 0.25 μg/mL in 15 of 38 isolates and 0.5 μg/mL in 10 of 38 isolates. In conclusion, although ERT and TIG were effective against B. melitensis isolates in vitro, further studies are needed in order to determine the use of these novel drugs in treatment of brucellosis.
ABSTRACT
Two regulons, soxRS and marRAB, are associated with resistance to quinolones or multiple antibiotic in Salmonella enterica serovar Typhimurium. These regulons are activated by nitric oxide and redox-cycling drugs, such as paraquat and cause on activation of the acrAB-encoded efflux pump. In this study, we investigated the effect of nitric oxide (NO) alone and in combination with ofloxacin, ciprofloxacin, and pefloxacin against S. typhimurium clinical isolates and mutant strains in vitro. We did not observe synergistic effect against clinical isolates and SH5014 (parent strain of acr mutant), while we found synergistic effect against PP120 (soxRS mutant) and SH7616 (an acr mutant) S. typhimurium for all quinolones. Our results suggest that the efficiencies of some antibiotics, including ofloxacin, ciprofloxacin, and pefloxacin are decreased via activation of soxRS and marRAB regulons by NO in S. enterica serovar Typhimurium. Further studies are warranted to establish the interaction of NO with the genes of Salmonella and, with multiple antibiotic resistance