Characterisation of Neisseria meningitidis cc11/ET-15 variant by whole genome sequencing

BACKGROUND Neisseria meningitidis strains belonging to clonal complex 11 is the cause of numerous outbreaks and epidemics in the United States, Canada and Europe, accounting for 49.5% of cases of meningococcal disease caused by serogroup C worldwide. In Brazil, it is the second most frequent clonal complex within this serogroup. The genetic characterisation of cc11/ET-15 variants is important for the epidemiological monitoring of meningococcal disease, through the identification of circulating epidemic clones, to support specific actions of Health Surveillance aiming outbreaks control. OBJECTIVES The objective of this study was to identify features in the genome of cc11/ET-15 clones through whole-genome sequencing (WGS), that differ from cc11/non-ET-15 strains that could explain their virulence. METHODS The whole genome of three cc11/ET-15 representative strains were sequenced with a minimum coverage of 100X with the MiSeq System and compared to the genome of cc11/non-ET-15 strains. RESULTS Genome analysis of cc11/ET-15 variants showed the presence of resistance factors, mobile genetic elements and virulence factors not found in cc11/non-ET-15 strains. MAIN CONCLUSIONS Our results show that these strains carry virulence factors not identified in cc11/non-ET-15 strains, which could explain the high lethality rates attributed to this clone worldwide.

Utilização de caldo Bolton no enriquecimento seletivo em comparação ao plaqueamento direto na pesquisa de Campylobacter spp. em carcaças resfriadas de frango / Use of Bolton broth for selective enrichment and comparative analysis of its performance with direct plating methodology for isolating

O objetivo deste estudo foi comparar o enriquecimento seletivo e o plaqueamento direto no isolamento das espécies termofílicas de Campylobacter spp. em 30 amostras de carcaças de frango resfriadas adquiridas em supermercados, feiras livres e abatedouros no município do Rio de Janeiro, no período de julho de 2009 a julho de 2010. Foi realizada a enxaguadura da carcaça com água peptonada tamponada a 1% para recuperação das bactérias. Para o plaqueamento direto, foram utilizados ágar carvão cefoperazone de soxicolato modificado e ágar campy-cefex. Para o enriquecimento seletivo, foi empregado o caldo Bolton em concentrações simples e dupla. Foi detectada a presença de Campylobacter spp. em 21 amostras(70%), sendo 6 (28,6%) de abatedouros (3 com Serviço de Inspeção Estadual e 3 sem inspeção), 8 (38,1%) de supermercados e 7 (33,3%) de feiras livres. Não houve diferença estatisticamente significativa entre os resultados obtidos nesses estabelecimentos. As 21 amostras positivas foram isoladas do plaqueamento direto, 2 (9,5%) foram isoladas também no caldo Bolton simples e nenhuma no caldo Bolton duplo. O plaqueamento direto foi considerado o método mais rápido e eficiente, e apresenta menor custo que o enriquecimento seletivo na recuperação de Campylobacter spp. em carcaças resfriadas de frango.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.