Molecular genotyping and epidemiology of Mycobacterium tuberculosis isolates obtained from inmates of correctional institutions of Campinas, Southeast Brazil

The objective of this study was to investigate the possible transmission of tuberculosis among 39 inmates with positive Mycobacterium tuberculosis smears in four correctional institutions located in Campinas City, SP, Brazil over a 19-month period. Fifty-one M. tuberculosis isolates from these inmates were characterized according to the number of IS6110 insertion elements present in their genomic DNA. The number of insertion elements in M. tuberculosis isolates varied from two to twelve. The dendrogram of similarity resulted in the grouping the isolates in six main clusters. These results, associated to epidemiological data, suggested the transmission of tuberculosis among inmates of the same and different institutions inmates. Univariate analysis of epidemiological data (total delay for beginning of treatment, previous treatment, and HIV status) and clustering occurrence showed that only "previous treatment" (OR = 7.65, p = 0.032) was associated with the possible transmission of tuberculosis in the studied prisons.

Epidemiological characterization of resistance and PCR typing of Shigella flexneri and Shigella sonnei strains isolated from bacillary dysentery cases in Southeast Brazil

Shigella spp are Gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the Enterobacteriaceae family responsible for "Shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. However, despite this, there are very few epidemiological studies about this bacterium in Brazil. We studied the antibiotic resistance profiles and the clonal structure of 60 Shigella strains (30 S. flexneri and 30 S. sonnei) isolated from shigellosis cases in different cities within the metropolitan area of Campinas, State of São Paulo, Brazil. We used the following well-characterized molecular techniques: enterobacterial repetitive intergenic consensus, repetitive extragenic palindromic, and double-repetitive element-polymerase chain reaction to characterize the bacteria. Also, the antibiotic resistance of the strains was determined by the diffusion disk method. Many strains of S. flexneri and S. sonnei were found to be multi-resistant. S. flexneri strains were resistant to ampicillin in 83.3 percent of cases, chloramphenicol in 70.0 percent, streptomycin in 86.7 percent, sulfamethoxazole in 80.0 percent, and tetracycline in 80.0 percent, while a smaller number of strains were resistant to cephalothin (3.3 percent) and sulfazotrim (10.0 percent). S. sonnei strains were mainly resistant to sulfamethoxazole (100.0 percent) and tetracycline (96.7 percent) and, to a lesser extent, to ampicillin (6.7 percent) and streptomycin (26.7 percent). Polymerase chain reaction-based typing supported the existence of specific clones responsible for the shigellosis cases in the different cities and there was evidence of transmission between cities. This clonal structure would probably be the result of selection for virulence and resistance phenotypes. These data indicate that the human sanitary conditions of the cities investigated should be improved.