RESUMO
As the human population grows, an increase in food trade is needed. This elevates the risk of epidemiological outbreaks. One of the prevalent pathogens associated with food production in Mexico has been Salmonella Oranienburg. Effective surveillance systems require microbial genetic knowledge. The objective of this work is to describe the genetic composition of Mexican S. Oranienburg genomes. For that, 53 strains from different environmental sources were isolated and sequenced. Additionally, 109 S. Oranienburg genomes were downloaded. Bioinformatic analyses were used to explore the clonal complex and genomic relatedness. A major clonal group formed by ST23 was identified comprising four STs. 202 SNPs were found the maximum difference among isolates. Virulence genes for host invasion and colonization as rpoS, fimbria type 1, and, T3SS were found common for all isolates. This study suggests that Mexican S. Oranienburg strains are potential pathogens circulating continuously in the region between host and non-host environments.
Assuntos
Genômica , Humanos , MéxicoRESUMO
Salmonella enterica is a pathogenic bacterium responsible for intestinal illness and systemic diseases such as typhoid and paratyphoid fevers. Among clinical manifestation classification, non-typhoidal Salmonella is mainly known as foodborne pathogen associated with the consumption of fecal contaminated food and water. Even though Salmonella hosts include humans and warm-blooded animals, it has been found in non-host environments as river water where the bacteria use different strategies to fitness the environment persisting and establishment. Now with the availability of WGS and bioinformatics tools, we can explore bacterial genomes with higher resolution to increase our understanding of specific genetic signatures among environmental and clinical isolates, being the goal of this work. Pangenome construction allowed the detection of specific environmental and clinical gene clusters related to metabolism and secretion systems as the main signature respectively. Specifically, D-galactonate degradation pathway was observed mainly in environmental genomes while T3SS and flagellum genes were detected for all clinical but not for all environmental isolates. Gene duplication and pseudogenes accumulation were detected as the main adaptation strategy for environmental isolates; thus, isolation source may play an important role in genome plasticity, conferring a selective advantage to survive and persist for environmental Salmonella isolates. Intact prophage sequences with cargo genes were observable for both isolation sources playing an important role in virulence contribution.
Assuntos
Adaptação Biológica/genética , Biologia Computacional , Genes Bacterianos , Genoma Bacteriano , Família Multigênica , Salmonella enterica/genética , Sequenciamento Completo do GenomaRESUMO
The objective of this study was to evaluate the effect of herbage allowance on pasture DM consumption by growing European wild boar. An additional objective was to evaluate the influence of pasture consumption on supplemental diet intake and BW gain. A previously sown grass-clover pasture was managed by cutting to obtain an herbage mass equivalent to 1,500 kg/ha DM. Areas of pasture were limited by fencing to obtain 3 different herbage allowances whereas the pasture was removed in other areas. Forty-eight purebred European wild boars (initial age of 120 d and initial BW of 14.4 kg) were grouped in pairs and each pair was randomly allotted to 1 of 4 treatments (6 pairs per treatment): no pasture (4 m(2); pasture removed), low (5.33 m(2); 400 g/d pasture DM available/wild boar), medium (8 m(2); 600 g/d pasture DM available/wild boar), and high (16 m(2); 1,200 g/d pasture DM available/wild boar). The treatment areas were moved daily with a 7-d rotation. For a 28-d period, wild boars entered their treatment areas from 0830 to 1630 h, after which they had free access to a supplemental diet for 1 h. Pasture consumption was estimated daily by cutting pasture samples pre- and postgrazing. Supplemental diet consumption was determined daily (feed offered minus remaining feed). Animals were weighed weekly. Pasture consumption differed (P < 0.001) among wild boars receiving different treatments, with cumulative consumptions of 3.0 and 3.9 kg DM/wild boar over 28 d for low and medium herbage allowances, respectively (P < 0.09), and 6.4 kg DM/wild boar over 28 d for high herbage allowance, with the latter consumption being greater (P < 0.001) than the consumption recorded with the decreased herbage allowance treatments. The supplemental diet consumption tended (P = 0.16) to be less in wild boars with greater herbage allowance. European wild boars with access to pasture had greater (8.48 vs. 6.27 kg; P = 0.002) BW gain than those without access to pasture. In conclusion, pasture consumption by European wild boars can be enhanced by increasing herbage allowance and greater BW gains can be achieved in wild boars with access to pasture compared with those with no pasture access.