RESUMO
In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013-2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa.
Assuntos
Genoma Bacteriano , Meningite Meningocócica/microbiologia , Neisseria meningitidis Sorogrupo C/genética , Neisseria meningitidis/genética , Antígenos de Bactérias/genética , Doenças Transmissíveis Emergentes , DNA Bacteriano , Farmacorresistência Bacteriana/genética , Epidemias , Variação Genética , Humanos , Meningite Meningocócica/epidemiologia , Tipagem Molecular , Neisseria meningitidis/isolamento & purificação , Neisseria meningitidis Sorogrupo C/isolamento & purificação , Níger/epidemiologia , Filogenia , Análise de Sequência de DNA , SorotipagemRESUMO
Staphylococcus simulans biovar staphylolyticus contains five plasmids designated pACK1-pACK5. The complete nucleotide sequences of pACK1 (55171bp) and pACK3 (28613bp) were determined and sequence comparison revealed that the entire pACK3 sequence is present on pACK1 (99.98% identical on the nucleotide level) with the sequence unique to pACK1 located between sin and blaZ, which are adjacent in pACK3. The common region contains the staphylococcal beta-lactamase transposon Tn552 and ORFs with similarity to genes encoding a serine-recombinase, enzymes involved in pantothenate biosynthesis, and components of the secA2 region involved in bacterial adherence to host tissues. The common region also contains a cluster of six ORFs that share no significant similarity to sequences previously described in GenBank. The region unique to pACK1, in addition to the genes for lysostaphin and lysostaphin resistance, contains ORFswith similarity to genes encoding a toxin-antitoxin addiction system and proteins involved in plasmid partitioning. The unique region also contains several ORFs that are similar to genes typically found on the chromosome such as those encoding catalase, ferrochelatase, and an enzyme involved in pantothenate biosynthesis. In pACK1, the ends of the unique region contain IS431 elements with direct repeats marking the points where the two plasmid sequences diverge. Several observations suggest that pACK1 was derived by insertion of the unique region into pACK3.
Assuntos
Genes Bacterianos/genética , Plasmídeos/química , Plasmídeos/genética , Staphylococcus/genética , beta-Lactamases/genética , Proteínas de Bactérias/genética , Sequência de Bases , Elementos de DNA Transponíveis/genética , Lisostafina , Fases de Leitura Aberta/genética , Homologia de Sequência do Ácido NucleicoRESUMO
Chagas disease, an important cause of heart disease in Latin America, is caused by the parasite Trypanosoma cruzi, which typically is transmitted to humans by triatomine insects. Although autochthonous transmission of the Chagas parasite to humans is rare in the United States, triatomines are common, and more than 20 species of mammals are infected with the Chagas parasite in the southern United States. Chagas disease has also been detected in colonies of nonhuman primates (NHP) in Georgia and Texas, and heart abnormalities consistent with Chagas disease have occurred at our NHP center in Louisiana. To determine the level of T. cruzi infection, we serologically tested 2157 of the approximately 4200 NHP at the center; 34 of 2157 primates (1.6%) tested positive. Presence of the T. cruzi parasite was confirmed by hemoculture in 4 NHP and PCR of the cultured parasites. These results strongly suggest local transmission of T. cruzi, because most of the infected NHP were born and raised at this site. All 3 species of NHP tested yielded infected animals, with significantly higher infection prevalence in pig-tailed macaques, suggesting possible exploration of this species as a model organism. The local T. cruzi strain isolated during this study would enhance such investigations. The NHP at this center are bred for use in scientific research, and the effects of the Chagas parasite on infected primates could confuse the interpretation of other studies.