A major challenge in the treatment of Tuberculosis (TB) is emergence of Multi-Drug Resistant <em>Mycobacterium tuberculosis</em> (MDRTB) strains. Efflux genes have been established to be among factors for ...A major challenge in the treatment of Tuberculosis (TB) is emergence of Multi-Drug Resistant <em>Mycobacterium tuberculosis</em> (MDRTB) strains. Efflux genes have been established to be among factors for drug resistance in <em>Mycobacterium tuberculosis</em> (<em>M. tuberculosis</em>) pulmonary infections by conferring bacterial ability to pump-out drugs from intracellular compartment, making it impossible for drugs to attain intracellular concentration lethal to the organism. There is paucity of data on the role of efflux pump in MDRTB in Nigerian strains of<em> M. tuberculosis</em>. Hence, the aim of this study was to detect the carriage, distribution and frequency of efflux pump genes among MDRTB and non-MDRTB isolates from participants with pulmonary tuberculosis in Lagos, Nigeria. This study was carried out on <em>M. tuberculosis</em> isolated from 1020 participants suspected of pulmonary tuberculosis in Lagos State, Nigeria. A total of 78 <em>M. tuberculosis</em> isolates were obtained from the participants suspected of pulmonary tuberculosis. Forty Eight isolates were confirmed as MDRTB and 30 non-MDRTB. Efflux pump genes were investigated in the isolates using the conventional polymerase chain reaction. Statistical analysis was carried out using the Statistical Package for Social Science (SPSS version 20) to compare the efflux pump gene results between MDRTB and non- MDRTB isolates. Different efflux genes types and frequency were detected in MDRTB and non-MDRTB isolates. Carriage of 2 or more alleles of efflux gene types Rv2486c (efpA), Rv2459c (jefA), Rv1877, Rv1002c, Rv0342, Rv2686c and drrC associated with MDR were detected. Additionally, the frequency of efflux genes alleles in MDRTB was significantly different from those in non- MDRTB isolates.展开更多
The present study focused on MexCD-OprJ efflux pump and its regulatory gene nfxB in multidrug resistant (MDR) clinical isolates of Pseudomonas aeruginosa collected from Kerala, South India. Semi-quantitative reverse t...The present study focused on MexCD-OprJ efflux pump and its regulatory gene nfxB in multidrug resistant (MDR) clinical isolates of Pseudomonas aeruginosa collected from Kerala, South India. Semi-quantitative reverse transcription-PCR technique was employed to detect hyperexpression of the efflux pump gene, mexD. Amplicons from nfxB gene of isolates hyperexpressing the efflux pump were sequenced for mutational and phylogenetic analysis. Among 29 isolates of MDR P. aeruginosa, increased mexD transcription was detected in 10.3% of the isolates when compared with P. aeruginosa reference strain, PAO (MTCC-3541). Various synonymous and non-synonymous mutations in nfxB regulatory gene sequences were detected. Notably, mutations detected in the strains designate Pa6 and Pa7 have been found to be novel and are hitherto unreported in GenBank data base. The genetic divergence and homogeneity of the nfxB regulatory gene sequences of mexCD-oprJ operon were clearly apparent in the phylogram generated employing similar sequences retrieved from the public database.展开更多
To evaluate the role of biofilm formation on the resistance of Helicobacter pylori (H. pylori) to commonly prescribed antibiotics, the expression rates of resistance genes in biofilm-forming and planktonic cells were ...To evaluate the role of biofilm formation on the resistance of Helicobacter pylori (H. pylori) to commonly prescribed antibiotics, the expression rates of resistance genes in biofilm-forming and planktonic cells were compared.METHODSA collection of 33 H. pylori isolates from children and adult patients with chronic infection were taken for the present study. The isolates were screened for biofilm formation ability, as well as for polymerase chain reaction (PCR) reaction with HP1165 and hp1165 efflux pump genes. Susceptibilities of the selected strains to antibiotic and differences between susceptibilities of planktonic and biofilm-forming cell populations were determined. Quantitative real-time PCR (qPCR) analysis was performed using 16S rRNA gene as a H. pylori-specific primer, and two efflux pumps-specific primers, hp1165 and hefA.RESULTSThe strains were resistant to amoxicillin, metronidazole, and erythromycin, except for one strain, but they were all susceptible to tetracycline. Minimum bactericidal concentrations of antibiotics in the biofilm-forming cells were significantly higher than those of planktonic cells. qPCR demonstrated that the expression of efflux pump genes was significantly higher in the biofilm-forming cells as compared to the planktonic ones.CONCLUSIONThe present work demonstrated an association between H. pylori biofilm formation and decreased susceptibility to all the antibiotics tested. This decreased susceptibility to antibiotics was associated with enhanced functional activity of two efflux pumps: hp1165 and hefA.展开更多
文摘A major challenge in the treatment of Tuberculosis (TB) is emergence of Multi-Drug Resistant <em>Mycobacterium tuberculosis</em> (MDRTB) strains. Efflux genes have been established to be among factors for drug resistance in <em>Mycobacterium tuberculosis</em> (<em>M. tuberculosis</em>) pulmonary infections by conferring bacterial ability to pump-out drugs from intracellular compartment, making it impossible for drugs to attain intracellular concentration lethal to the organism. There is paucity of data on the role of efflux pump in MDRTB in Nigerian strains of<em> M. tuberculosis</em>. Hence, the aim of this study was to detect the carriage, distribution and frequency of efflux pump genes among MDRTB and non-MDRTB isolates from participants with pulmonary tuberculosis in Lagos, Nigeria. This study was carried out on <em>M. tuberculosis</em> isolated from 1020 participants suspected of pulmonary tuberculosis in Lagos State, Nigeria. A total of 78 <em>M. tuberculosis</em> isolates were obtained from the participants suspected of pulmonary tuberculosis. Forty Eight isolates were confirmed as MDRTB and 30 non-MDRTB. Efflux pump genes were investigated in the isolates using the conventional polymerase chain reaction. Statistical analysis was carried out using the Statistical Package for Social Science (SPSS version 20) to compare the efflux pump gene results between MDRTB and non- MDRTB isolates. Different efflux genes types and frequency were detected in MDRTB and non-MDRTB isolates. Carriage of 2 or more alleles of efflux gene types Rv2486c (efpA), Rv2459c (jefA), Rv1877, Rv1002c, Rv0342, Rv2686c and drrC associated with MDR were detected. Additionally, the frequency of efflux genes alleles in MDRTB was significantly different from those in non- MDRTB isolates.
文摘The present study focused on MexCD-OprJ efflux pump and its regulatory gene nfxB in multidrug resistant (MDR) clinical isolates of Pseudomonas aeruginosa collected from Kerala, South India. Semi-quantitative reverse transcription-PCR technique was employed to detect hyperexpression of the efflux pump gene, mexD. Amplicons from nfxB gene of isolates hyperexpressing the efflux pump were sequenced for mutational and phylogenetic analysis. Among 29 isolates of MDR P. aeruginosa, increased mexD transcription was detected in 10.3% of the isolates when compared with P. aeruginosa reference strain, PAO (MTCC-3541). Various synonymous and non-synonymous mutations in nfxB regulatory gene sequences were detected. Notably, mutations detected in the strains designate Pa6 and Pa7 have been found to be novel and are hitherto unreported in GenBank data base. The genetic divergence and homogeneity of the nfxB regulatory gene sequences of mexCD-oprJ operon were clearly apparent in the phylogram generated employing similar sequences retrieved from the public database.
文摘To evaluate the role of biofilm formation on the resistance of Helicobacter pylori (H. pylori) to commonly prescribed antibiotics, the expression rates of resistance genes in biofilm-forming and planktonic cells were compared.METHODSA collection of 33 H. pylori isolates from children and adult patients with chronic infection were taken for the present study. The isolates were screened for biofilm formation ability, as well as for polymerase chain reaction (PCR) reaction with HP1165 and hp1165 efflux pump genes. Susceptibilities of the selected strains to antibiotic and differences between susceptibilities of planktonic and biofilm-forming cell populations were determined. Quantitative real-time PCR (qPCR) analysis was performed using 16S rRNA gene as a H. pylori-specific primer, and two efflux pumps-specific primers, hp1165 and hefA.RESULTSThe strains were resistant to amoxicillin, metronidazole, and erythromycin, except for one strain, but they were all susceptible to tetracycline. Minimum bactericidal concentrations of antibiotics in the biofilm-forming cells were significantly higher than those of planktonic cells. qPCR demonstrated that the expression of efflux pump genes was significantly higher in the biofilm-forming cells as compared to the planktonic ones.CONCLUSIONThe present work demonstrated an association between H. pylori biofilm formation and decreased susceptibility to all the antibiotics tested. This decreased susceptibility to antibiotics was associated with enhanced functional activity of two efflux pumps: hp1165 and hefA.
