Pandemic extra-intestinal pathogenic Escherichia coli (ExPEC) clonal group O6-B2-ST73 as a cause of avian colibacillosis in Brazil

Extra-intestinal pathogenic Escherichia coli (ExPEC) represent an emerging pathogen, with pandemic strains increasingly involved in cases of urinary tract infections (UTIs), bacteremia, and meningitis. In addition to affecting humans, the avian pathotype of ExPEC, avian pathogenic E. coli (APEC), causes severe economic losses to the poultry industry. Several studies have revealed overlapping characteristics between APEC and human ExPEC, leading to the hypothesis of a zoonotic potential of poultry strains. However, the description of certain important pandemic clones, such as Sequence Type 73 (ST73), has not been reported in food sources. We characterized 27 temporally matched APEC strains from diverse poultry farms in Brazil belonging to the O6 serogroup because this serogroup is frequently described as a causal factor in UTI and septicemia in humans in Brazil and worldwide. The isolates were genotypically characterized by identifying ExPEC virulence factors, phylogenetically tested by phylogrouping and multilocus sequence type (MLST) analysis, and compared to determine their similarity employing the pulsed field gel electrophoresis (PFGE) technique. The strains harbored a large number of virulence determinants that are commonly described in uropathogenic E. coli (UPEC) and sepsis associated E. coli (SEPEC) strains and, to a lesser extent in neonatal meningitis associated E. coli (NMEC), such as pap (85%), sfa (100%), usp (100%), cnf1 (22%), kpsMTII (66%), hlyA (52%), and ibeA (4%). These isolates also yielded a low prevalence of some genes that are frequently described in APEC, such as iss (37%), tsh, ompT, and hlyF (8% each), and cvi/cva (0%). All strains were classified as part of the B2 phylogroup and sequence type 73 (ST73), with a cluster of 25 strains showing a clonal profile by PFGE. These results further suggest the zoonotic potential of some APEC clonal lineages and their possible role in the epidemiology of human ExPEC, in addition to providing the first description of the O6-B2-ST73 clonal group in poultry.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESPUniv Sao Paulo, Dept Pathol, Fac Med Vet & Zootecnia, Sao Paulo, BrazilUniv Sao Paulo, Dept Vet Prevent Med, Fac Med Vet & Zootecnia, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Microbiol Immunol & Parasitol, Escola Paulista Med, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Microbiol Immunol & Parasitol, Escola Paulista Med, Sao Paulo, BrazilFAPESP: 05/57500-9-TFAPESP: 11/182046-TFAPESP: 14/11523-7]Web of Scienc

Analysis of the Virulence of an Atypical Enteropathogenic Escherichia coli Strain In Vitro and In Vivo and the Influence of Type Three Secretion System

Atypical enteropathogenic Escherichia coli (aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytes in vitro (Caco-2 cells) and in vivo (rabbit ileal loops) and to translocate the rat intestinal mucosa in vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potential in vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasion in vitro and in vivo and to bacterial translocation to extraintestinal sites

Os livros brancos da defesa da República Popular da China 1998-2010

Este estudo é uma análise da evolução das perceções de (in)segurança da República Popular da China (RPC), através da aferição quantitativa e qualitativa de expressões idiomáticas caracterizadoras da evolução do sistema internacional, as quais foram selecionadas e associadas a tais perceções, e que constam das sete edições do Livro Branco da Defesa publicadas pelo Conselho de Estado entre 1998 e 2010. Procura-se através de um enquadramento conceptual e metodológico derivado da análise crítica do discurso baseado nas teorias de Michel Foucault e de Norman Fairclough, bem como do da perceção de ameaças por parte dos Estados no sistema internacional formulado por Robert Jervis, identificar e justificar variações nas perceções de (in)segurança da RPC entre 1998 e 2010, concluindo-se que estas refletem uma visão de natureza essencialmente realista estrutural e Lockeana quanto à evolução do sistema internacional

Escherichia coli Strains of Serotype O51:H40 Comprise Typical and Atypical Enteropathogenic E. coli Strains and Are Potentially Diarrheagenic▿

Escherichia coli strains of serotype O51:H40 were studied with regard to the presence of several virulence properties and their genetic diversity and enteropathogenicity in rabbit ileal loops. This serotype encompasses potential enteropathogenic strains mostly classified as being atypical enteropathogenic E. coli (EPEC) strains, which are genetically closer to enterohemorrhagic E. coli than to typical EPEC strains

IDENTIFICAÇÃO DE KLEBSIELLA SPP. NAS FEZES DE PSITACÍDEOS CATIVOS

More than 80 species of birds belonged to the family Psittacidae in Brazil, including parrots, macaws and parakeets. The maintenance of these birds in Zoos may help the conservation of the species, but the captivity can favor intestinal colonization by enterobacteria. The aim of this study was to identify the presence of Klebsiella spp. in the fecal samples of captive parrots. Thirty - four fecal samples were analyzed. The results showed that 11 (32.35%) were positive for Klebsiella spp., with identification of the species: K. pneumoniae and K. oxytoca. This study showed a high frequency of birds colonized by Klebsiella spp. Further studies are required to determine the pathogenicity, the antimicrobial resistance profile and zoonotic risks