Genetically distinct lineages of Salmonella Typhimurium ST313 and ST19 are present in Brazil.

In sub-Saharan Africa, two genetically distinct lineages of multi-drug resistant non-typhoidal Salmonella (NTS) serovar Typhimurium sequence type 313 (ST313) are known to cause invasive disease among people. S. Typhimurium ST313 has evolved to become more human-adapted and is commonly isolated from systemic sites (eg., blood) from febrile patients in sub-Saharan Africa. Epidemiological studies indicate that S. Typhimurium is frequently isolated from systemic sites from human patients in Brazil, however, it is currently unknown if this pathogen has also evolved to become more invasive and human-adapted in this country. Here we determined genotypic and phenotypic divergence among clinical S. Typhimurium strains isolated from systemic and non-systemic sites from human patients in Brazil. We report that a subset (8/38, 20%) of epidemiologically diverse human clinical strains of S. Typhimurium recovered from systemic sites in Brazil show significantly higher intra-macrophage survival, indicating that this subset is likely more invasive. Using the whole genome sequencing and phylogenetic approaches, we identified S. Typhimurium ST313-lineage in Brazil that is genetically and phenotypically distinct from the known African ST313-lineages. We also report the identification of S. Typhimurium ST19-lineage in Brazil that is evolving similar to ST313 lineages from Africa but is genetically and phenotypically distinct from ST19-lineage commonly associated with the gastrointestinal disease worldwide. The identification of new S. Typhimurium ST313 and ST19 lineages responsible for human illnesses in Brazil warrants further epidemiological investigations to determine the incidence and spread of a genetically divergent population of this important human pathogen.

Draft Genome Sequences of 11 Salmonella enterica Serovar Typhimurium Strains Isolated from Human Systemic and Nonsystemic Sites in Brazil.

Salmonella enterica serovar Typhimurium strains isolated from systemic sites outside sub-Saharan Africa have been rarely sequenced. Here, we report the draft genome sequences of S Typhimurium sequence type 19 (ST19) (n = 9), ST1649 (n = 1), and ST313 (n = 1) strains isolated from human systemic (e.g., blood) and nonsystemic (e.g., stool and wounds) sites in Brazil.

Draft Genome Sequences of Salmonella enterica subsp. enterica Serovar Typhimurium Strains Isolated from Chicken and Swine Carcasses in Two Distinct Geographical Regions from Rio de Janeiro State, Brazil.

Salmonella enterica subsp. enterica serovar Typhimurium is a surveyed worldwide serotype with well-characterized genomes for several different strains. In Brazil, very few studies have submitted whole-genome sequences to GenBank. This genome may be useful to analyze the genetic mechanisms comparable to those of other related studies conducted in Brazil and globally.

Investigation of enrofloxacin residues in broiler tissues using ELISA and LC-MS/MS.

This study investigated the efficiency of an enrofloxacin ELISA test kit to detect the presence of enrofloxacin residues in broiler tissues compared with LC-MS/MS. Broiler tissues from 72 samples consisting of 60 breast muscle, six pools of livers (500 g each) and six pools of kidneys (500 g each) were obtained from six different slaughterhouses. Breast muscle from 10 carcasses and pools of livers and kidneys from approximately 200 carcasses of the same flock were collected from each slaughterhouse. ELISA and HPLC were used to identify and quantify the contamination of the samples with enrofloxacin. A total of 72% of the analysed samples contained enrofloxacin residues detected by the ELISA and 22.2% were detected by LC-MS/MS. The mean values of enrofloxacin contamination found in chicken breast by ELISA and HPLC were 8.63 and 12.25 µg kg(-1), respectively. None of the samples exceeded the maximum limit of 100 µg kg(-1) by both methods set by the European Union as well as the Brazilian Agriculture Ministry. All positive samples for enrofloxacin residues detected by LC-MS/MS were also positive by ELISA. These data confirm the efficiency of the ELISA test, and suggest its use as a screening method for enrofloxacin residues in poultry tissues due to its quick results, low price and ease of applicability.