Migration and tuberculosis transmission in a middle-income country: a cross-sectional study in a central area of São Paulo, Brazil.

BACKGROUND: Little is known about the impact of growing migration on the pattern of tuberculosis (TB) transmission in middle-income countries. We estimated TB recent transmission and its associated factors and investigated the presence of cross-transmission between South American migrants and Brazilians. METHODS: We studied a convenient sample of cases of people with pulmonary TB in a central area of São Paulo, Brazil, diagnosed between 2013 and 2014. Cases with similar restriction fragment length polymorphism (IS6110-RFLP) patterns of their Mycobacterium tuberculosis complex isolates were grouped in clusters (recent transmission). Clusters with both Brazilian and South American migrants were considered mixed (cross-transmission). Risk factors for recent transmission were studied using logistic regression. RESULTS: Isolates from 347 cases were included, 76.7% from Brazilians and 23.3% from South American migrants. Fifty clusters were identified, which included 43% South American migrants and 60.2% Brazilians (odds ratio = 0.50, 95% confidence interval = 0.30-0.83). Twelve cross-transmission clusters were identified, involving 24.6% of all clustered cases and 13.8% of all genotyped cases, with migrants accounting for either an equal part or fewer cases in 11/12 mixed clusters. CONCLUSIONS: Our results suggest that TB disease following recent transmission is more common among Brazilians, especially among those belonging to high-risk groups, such as drug users. Cross-transmission between migrants and Brazilians was present, but we found limited contributions from migrants to Brazilians in central areas of São Paulo and vice versa

Viability of stressed Mycobacterium tuberculosis and association with multidrug resistance

This study investigated biological characteristics of recovered stressed M. tuberculosis isolates that failed to grow in differential culture media for phenotypic identification and in culture media containing anti-tuberculosis drugs for drug-susceptibility testing, despite of having grown in primary culture. It represents an improvement in the diagnosis of MDR tuberculosis and tuberculosis control

Reliable identification of mycobacterial species by PCR-restriction enzyme analysis (PRA)-hsp65 in a reference laboratory and elaboration of a sequence-based extended algorithm of PRA-hsp65 patterns

<p>Abstract</p> <p>Background</p> <p>Identification of nontuberculous mycobacteria (NTM) based on phenotypic tests is time-consuming, labor-intensive, expensive and often provides erroneous or inconclusive results. In the molecular method referred to as PRA-<it>hsp65</it>, a fragment of the <it>hsp65 </it>gene is amplified by PCR and then analyzed by restriction digest; this rapid approach offers the promise of accurate, cost-effective species identification. The aim of this study was to determine whether species identification of NTM using PRA-<it>hsp65 </it>is sufficiently reliable to serve as the routine methodology in a reference laboratory.</p> <p>Results</p> <p>A total of 434 NTM isolates were obtained from 5019 cultures submitted to the Institute Adolpho Lutz, Sao Paulo Brazil, between January 2000 and January 2001. Species identification was performed for all isolates using conventional phenotypic methods and PRA-<it>hsp65</it>. For isolates for which these methods gave discordant results, definitive species identification was obtained by sequencing a 441 bp fragment of <it>hsp65</it>. Phenotypic evaluation and PRA-<it>hsp65 </it>were concordant for 321 (74%) isolates. These assignments were presumed to be correct. For the remaining 113 discordant isolates, definitive identification was based on sequencing a 441 bp fragment of <it>hsp65</it>. PRA-<it>hsp65 </it>identified 30 isolates with <it>hsp65 </it>alleles representing 13 previously unreported PRA-<it>hsp65 </it>patterns. Overall, species identification by PRA-<it>hsp65 </it>was significantly more accurate than by phenotype methods (392 (90.3%) vs. 338 (77.9%), respectively; p < .0001, Fisher's test). Among the 333 isolates representing the most common pathogenic species, PRA-<it>hsp65 </it>provided an incorrect result for only 1.2%.</p> <p>Conclusion</p> <p>PRA-<it>hsp65 </it>is a rapid and highly reliable method and deserves consideration by any clinical microbiology laboratory charged with performing species identification of NTM.</p

Application of four molecular typing methods for analysis of Mycobacterium fortuitum group strains causing post-mammaplasty infections

A cluster of cases of post-augmentation mammaplasty surgical site infections occurred between 2002 and 2004 in Campinas, in the southern region of Brazil. Rapidly growing mycobacteria were isolated from samples from 12 patients. Eleven isolates were identified as Mycobacterium fortuitum and one as Mycobacterium porcinum by PCR-restriction digestion of the hsp65 gene. These 12 isolates, plus six additional M. fortuitum isolates from non-related patients, were typed by pulsed-field gel electrophoresis (PFGE) and three PCR-based techniques: 16S-23S rRNA internal transcribed spacer (ITS) genotyping; randomly amplified polymorphic DNA (RAPD) PCR; and enterobacterial repetitive intergenic consensus (ERIC) PCR. Four novel M. fortuitum allelic variants were identified by restriction analysis of the ITS fragment. One major cluster, comprising six M. fortuitum isolates, and a second cluster of two isolates, were identified by the four methods. RAPD-PCR and ITS genotyping were less discriminative than ERIC-PCR. ERIC-PCR was comparable to PFGE as a valuable complementary tool for investigation of this type of outbreak.Universidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilFleury Ctr Med Diagnost, São Paulo, BrazilInst Adolfo Lutz Registro, São Paulo, BrazilInst Vozza Med & Diagnose LTDA, Campinas, BrazilCtr Vigilancia Epidemiol Prof Alexandre Vranjac, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, SP, BrazilWeb of Scienc

IS1245 genotypic analysis of Mycobacterium avium isolates from patients in Brazil

AbstractObjective: Disseminated Mycobacterium avium infection is an emerging opportunistic disease among patients with acquired immunodeficiency syndrome (AIDS) in Brazil. The mode of transmission of M. avium in a developing country setting needs to be better characterized.Methods: Mycobacterium avium strain collections in São Paulo and Rio de Janeiro were analyzed according to the strains' IS1245 DNA gel electrophoretic migration patterns. Medical records of the patients from whom M. avium isolates were available were reviewed, and their demographic characteristics were stratified according to the isolates' IS1245 DNA fingerprint patterns.Results: Of 105 patients, 33 (31 %) with M. avium isolated between 1990 and 1994 had strains having IS1245 patterns identical in patterns seen in isolates from two or more patients (designated as cluster pattern strains). Cluster pattern strains were isolated from 21 (39%) of 54 patients with disseminated infection (defined as infection due to M. avium isolated from a sterile site in an adult patient). Six of the cluster pattern strains were isolated only from sterile sites. In São Paulo, cluster pattern strains were significantly more likely to be isolated from patients with disseminated disease.Conclusions: These preliminary observations suggest that in large cities of Brazil, a high proportion (at least 39%) of disseminated M. avium infections in patients with AIDS results from a recent transmission. Some strains of M. avium may be more likely to cause disseminated disease than others after an infection