Antimicrobial resistance and genetic background of non-typhoidal Salmonella enterica strains isolated from human infections in São Paulo, Brazil (2000-2019).

Salmonella enterica causes Salmonellosis, an important infection in humans and other animals. The number of multidrug-resistant (MDR) phenotypes associated with Salmonella spp. isolates is increasing worldwide, causing public health concern. Here, we aim to characterize the antimicrobial-resistant phenotype of 789 non-typhoidal S. enterica strains isolated from human infections in the state of São Paulo, Brazil, along 20 years (2000-2019). Among the non-susceptible isolates, 31.55, 14.06, and 13.18% were resistant to aminoglycosides, tetracycline, and ß-lactams, respectively. Moreover, 68 and 11 isolates were considered MDR and Extended Spectrum ß-Lactamase (ESBL) producers, respectively, whereas one isolate was colistin-resistant. We selected four strains to obtain a draft of the Genome Sequence; one S. Infantis (ST32), one S. Enteritidis (ST11), one S. I 4,[5],12:i:- (ST19), and one S. Typhimurium (ST313). Among them, three presented at least one of the following antimicrobial resistance genes (AMR) linked to mobile DNA: blaTEM-1B, dfrA1, tetA, sul1, floR, aac(6')-laa, and qnrE1. This is the first description of the plasmid-mediated quinolone resistance (PMQR) gene qnrE1 in a clinical isolate of S. I 4,[5],12:i:-. The S. Typhimurium is a colistin-resistant isolate, but did not harbor mcr genes, but it presented mutations within the mgrB, pmrB, and pmrC regions that might be linked to the colistin-resistant phenotype. The virulence pattern of the four isolates resembled the virulence pattern of the highly pathogenic S. Typhimurium UK-1 reference strain in assays involving the in vivo Galleria mellonella model. In conclusion, most isolates studied here are susceptible, but a small percentage present an MDR or ESBL-producer and pathogenic phenotype. Sequence analyses revealed plasmid-encoded AMR genes, such as ß-lactam and fluoroquinolone resistance genes, indicating that these characteristics can be potentially disseminated among other bacterial strains.

Prevalence, risk factors and molecular characteristics of meningococcal carriage among brazilian adolescents

BACKGROUND: In 2010, introduction of the meningococcal C conjugate vaccine in Brazil for children <2 years provided an immediate reduction in the incidence rates of disease among the age groups targeted for the vaccine, but no early impact was observed in unvaccinated age groups. Knowledge about meningococcal carriage is crucial for improving our understanding of the disease epidemiology and for designing effective vaccination programs. Taking in account the very limited published data currently available describing meningococcal carriage in Brazil, we performed a study to evaluate the prevalence of Neisseria meningitidis carriage among adolescent students. METHODS: A cross-sectional study was conducted in 2012 to assess the prevalence of meningococcal carriage among a representative sample of 1208 students 11­19 years of age in Campinas, Brazil. Genotypic and phenotypic characterization of isolated carriage strains and the effect of potential risk factors for carriage were also analyzed. Results: The overall carriage prevalence was 9.9% (95% confidence interval, 8.3­11.8%), with dominance of serogroup C (1.32%), followed by serogroups B (0.99%), E (0.74%), Y (0.49%) and W (0.25%). A lower level of education of the parents was independently associated with a higher risk of carriage. A high diversity of genotypes was found among carriage strains. CONCLUSIONS: The evidence gathered during this study provides estimates of carriage prevalence in Brazilian adolescents, showing an unusually high dominance of serogroup C. These results have important implications in future strategies to optimize the impact of the current meningococcal C vaccination program in Brazil

Prevalence, Risk Factors and Molecular Characteristics of Meningococcal Carriage Among Brazilian Adolescents.

BACKGROUND: In 2010, introduction of the meningococcal C conjugate vaccine in Brazil for children <2 years provided an immediate reduction in the incidence rates of disease among the age groups targeted for the vaccine, but no early impact was observed in unvaccinated age groups. Knowledge about meningococcal carriage is crucial for improving our understanding of the disease epidemiology and for designing effective vaccination programs. Taking in account the very limited published data currently available describing meningococcal carriage in Brazil, we performed a study to evaluate the prevalence of Neisseria meningitidis carriage among adolescent students. METHODS: A cross-sectional study was conducted in 2012 to assess the prevalence of meningococcal carriage among a representative sample of 1208 students 11-19 years of age in Campinas, Brazil. Genotypic and phenotypic characterization of isolated carriage strains and the effect of potential risk factors for carriage were also analyzed. RESULTS: The overall carriage prevalence was 9.9% (95% confidence interval, 8.3-11.8%), with dominance of serogroup C (1.32%), followed by serogroups B (0.99%), E (0.74%), Y (0.49%) and W (0.25%). A lower level of education of the parents was independently associated with a higher risk of carriage. A high diversity of genotypes was found among carriage strains. CONCLUSIONS: The evidence gathered during this study provides estimates of carriage prevalence in Brazilian adolescents, showing an unusually high dominance of serogroup C. These results have important implications in future strategies to optimize the impact of the current meningococcal C vaccination program in Brazil.