<b>Caracterização fenotípica e genotípica de <i>Escherichia coli</i> diarreiogênicas isoladas de psitacídeos de pequeno porte criados como \"pets\":</b> análise dos riscos zoonóticos

Abstract

Among the parrots (psittacidae family) kept as pets, the cockatiels (Nymphicus hollandicus), budgerigars (Melopsittacus undulatus) and lovebirds (Lovebirds spp.) stand out. Although the benefits from the presence of these birds in a household environment are acknowledged, little is known about the risks of transmission of zoonoses. E. coli can be isolated in various sites of the human and animal body. Some serotypes are considered as pathogenic, and in such cases, the infection may be associated with the occurrence of several clinical manifestations. The aim of the present study is to characterize, phenotypically and genotypically, diarrheagenic Escherichia coli, isolated from the small parrots kept as pets. One hundred and seventy-one fecal samples of birds living in households in the city of São Paulo were collected with the aid of sterile swabs, with 67 being from cockatiels, 59 from budgerigars, and 45 from lovebirds. From the 171 samples, 42 (22 from cockatiels, 10 from budgerigars and 10 from lovebirds) Escherichia coli colonies were identified, which had their DNA extracted, and the eae, bfpA, stx1, stx2, LT, ST and aggR; aaiA; aatA; aaiG genes were investigated, through Polymerase Chain Reaction (PCR). The results indicated positivity in ten isolates: eae + , bfpA + , Stx2f + from three cockatiels and five budgerigars (8/10), ST from one cockatiel (1/10), and eae + from one budgerigar (1/10). The eight STEC/tEPEC lineages were classified as O137:HNM, and none of the lineages showed a multiresistance antibiotic profile. Only one isolate was positive for biofilm formation (DO, 0.064), which was classified as weakly adherent. The phylogenetic analysis of the 4 groups by Clermont et al. (2013) classified three lineages as B2, two as F, and one as Clade II. Two lineages were classified as "non-typeable." The results for AFLP were: 7/8 lineages (three of cockatiels and four of budgerigars) were clustered together, with 90-100% of similarity being observed. The results of the internal fragment sequencing of housekeeping genes -Multi-locus Sequence Typing (MLST) revealed that the eight lineages belonged in to ST 3072. In this study, although none of the lineages showed hemolytic activity, they produced toxins in vitro. They adhered, in vitro, to HeLa cells and caused A/E lesions in an intestinal loop model of rabbits. The lineages induced an inflammatory process and an increase of intestinal mucus. This study data revealed the zoonotic potential of STEC/tEPEC hybrids, O137:HNM; ST 3072 serogroup, isolated from small-sized parrots kept as pets.

Theoretical exploration of competing phases of lattice Bose gases in a cavity

“…Finally we construct a self-consistent mean-field theory, by which we find there exists structural phase transition between different CDW phases driven by the hopping parameter. Currently, new research interests [32][33][34][35] including supersolidity breaking translational invariance and relaxation dynamics are being cultivated along the lines of global collective light-matter interaction.…”