Reconstruction of the spatial and temporal dynamics of hepatitis B virus genotype D in the Americas.

Hepatitis B virus (HBV) genotype D (HBV/D) is globally widespread, and ten subgenotypes (D1 to D10) showing distinct geographic distributions have been described to date. The evolutionary history of HBV/D and its subgenotypes, for which few complete genome sequences are available, in the Americas is not well understood. The main objective of the current study was to determine the full-length genomic sequences of HBV/D isolates from Brazil and frequency, origin and spread of HBV/D subgenotypes in the Americas. Complete HBV/D genomes isolated from 39 Brazilian patients infected with subgenotypes D1 (n = 1), D2 (n = 10), D3 (n = 27), and D4 (n = 1) were sequenced and analyzed together with reference sequences using the Bayesian coalescent and phylogeographic framework. A search for HBV/D sequences available in GenBank revealed 209 complete and 926 partial genomes from American countries (Argentina, Brazil, Canada, Chile, Colombia, Cuba, Haiti, Martinique, Mexico, USA and Venezuela), with the major circulating subgenotypes identified as D1 (26%), D2 (17%), D3 (36%), D4 (21%), and D7 (1%) within the continent. The detailed evolutionary history of HBV/D in the Americas was investigated by using different evolutionary time scales. Spatiotemporal reconstruction analyses using short-term substitution rates suggested times of the most recent common ancestor for the American HBV/D subgenotypes coincident with mass migratory movements to Americas during the 19th and 20th centuries. In particular, significant linkages between Argentina and Syria (D1), Brazil and Central/Eastern Europe (D2), USA and India (D2), and Brazil and Southern Europe (D3) were estimated, consistent with historical and epidemiological data.

Presence of OXA-23-producing isolates of Acinetobacter baumannii in wastewater from hospitals in southern Brazil.

The aim of the study was to evaluate the dissemination of multiresistant isolates of Acinetobacter baumannii carrying resistance genes, by samples of wastewater from hospitals in Porto Alegre, Rio Grande do Sul, Brazil. We obtained 303 bacterial isolates from the wastewater of three hospitals in Porto Alegre, Rio Grande do Sul. For each isolate, we determined the profile of susceptibility to antimicrobials and the presence of the genes bla(OXA-23), bla(OXA-24), bla(OXA-51), bla(OXA-58), bla(SPM-1), bla(IMP), and bla(VIM.) The bla(OXA-51) gene was found in 56% of the isolates, indicating the presence of A. baumannii in this environment. Of these, three multiresistant isolates were positive for the bla(OXA-23) gene, in wastewater from two of the hospitals. The results obtained in this study indicate that isolates of A. baumannii which are multiresistant and carry resistance genes such as bla(OXA-51) and bla(OXA-23) are being released into the environment in the wastewater from the hospitals analyzed. Multiresistant Acinetobacter junii, the newly emerging pathogen, were also found among the multiresistant isolates. Hospital wastewater may be crucial to the development and dispersal of multiresistant bacteria, making waterbodies reservoirs of bacterial resistance.