Mutations in an 81-bp region of the rpoB gene associated with rifampin resistance were studied in 41 rifampin-resistant clinical strains of Mycobacterium tuberculosis isolated in Turkey. Fourteen different rpoB alleles, three of which had not been reported before, were found. A reverse hybridization-based line probe assay (the Inno-LiPA Rif.TB test) for rapid detection of the mutations was evaluated with these isolates. Rifampin resistance was correctly identified in 23 of 41 isolates (56.1%) with the kit's R probes specific for these mutations. Seventeen of 41 isolates (41.5%) yielded hybridization patterns, with at least one negative signal obtained with the S probes for the wild type. One isolate was identified as rifampin sensitive by the line probe assay. The rate of concordance of the results of the line probe assay with the results of the in vitro susceptibility test was high (97.6%). These results demonstrate that the line probe assay kit may be useful for the rapid diagnosis of rifampin-resistant tuberculosis.Mycobacterium tuberculosis remains one of the most significant causes of death from an infectious agent, annually leading to 2 million deaths worldwide (4). As the incidence of tuberculosis has increased, there has been a corresponding rise in the incidence of drug-resistant strains of M. tuberculosis. Early diagnosis of the disease and rapid identification of resistance to primary antituberculosis agents are essential for efficient treatment and control of multidrug-resistant (MDR) strains. Rifampin (RIF) is one of the most potent antituberculosis drugs; therefore, resistance to RIF often results in high clinical relapse rates, particularly if RIF resistance is associated with resistance to other antituberculosis drugs (5, 14). Moreover, more than 90% of RIF-resistant isolates are also resistant to isoniazid; therefore, detection of RIF resistance could also identify MDR strains (3, 5, 17). The incidence of pulmonary tuberculosis in Turkey was 35.5 per 100,000 population in 2000. In the Aegean region, 8.2% of M. tuberculosis strains isolated between 1999 and 2001 were found to be resistant to RIF. During the same period, the incidence of resistance to both RIF and isoniazid was 6.8% (6).Collectively, DNA sequencing studies demonstrate that more than 95% of RIF-resistant M. tuberculosis strains have a mutation within the 81-bp hot-spot region (codons 507 to 533) of the RNA polymerase B subunit (rpoB) gene (9,10,12,13,15,16,18,20,21,23,24). In addition, other studies reveal that mutations associated with RIF resistance can also occur in other regions of the rpoB gene, although these occur less frequently (7,8). Several molecular methods have been developed in recent years to evaluate the rpoB gene for RIF resistance mutations, including DNA sequencing, line probe assay, and analysis with DNA microarrays (19). These molecular tests can also serve as a means of detecting molecular epidemiological markers, since the relative frequencies of the alleles associated with resistance can vary geographically ...
Cetrexidin and 2% chlorhexidine gluconate were more effective, and had more residual antibacterial effects and lower toxicity than 5.25% NaOCl solution.
Onychomycosis in childhood is reported to be unusual. The aim of this study was to determine the prevalence of onychomycosis in primary school children and to make comparison between different socioeconomic status in the rural and urban areas of the city. Hand and foot nails of 23235 children aged 7-14 were examined. Onychomycosis was suspected and nail scrapings for mycological examination were taken in 116 of them. Hyphae or spores were seen in 41 (0.18%) by direct microscopic examination, and mycological cultures were positive in 24 (0.1%) of them. Toenails were affected in all of the fungal culture positive cases. Trichosporon spp, Trichophyton rubrum, Candida albicans and Candida glabrata grew in 11, 6, 5 and 2 of the cultures respectively. Onychomycosis prevalence was significantly higher in the children living in the rural areas (p = 0.016) [Odds ratio = 3.43 (%95 CI 1.11
Infections caused by yeast of the genus Candida are the most common fungal infections, being Candida albicans the most common isolated species among them. The rapid identification of this yeast is mostly based on the production of germ tube in human or animal serum. This study describes the use of 12 different liquid media for germ tube production at 2, 2.5, 3 and 4 h. We examined 193 yeasts, including 157 (81.3%) C. albicans and 36 (18.7%) Candida tropicalis for the production of germ tube. The germ tube production of C. albicans was mostly observed in human serum (98%) followed by rabbit serum (89.8%), brain heart infusion broth (84%) and sheep serum (74.5%) at 2 h. An incubation time exceeding 2 h i.e. 2.5 h or later, C. tropicalis strains were observed to produce germ tubes. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for germ tube production of human serum at 2 h were 98%, 100%, 100% and 92.3% respectively. In all tested sera, an incubation period of more than 2 h improves the sensitivity, but decreases the specificity as well as PPV and NPV of germ tube test (GTT). In conclusion, human serum was observed to be the most appropriate medium to be preferred for GTT, with an incubation period of 2 h.
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