NC_011080:333121 Salmonella enterica subsp. enterica serovar Newport str. SL254,
Host Lineage: Salmonella enterica; Salmonella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: The SL254 strain is an MDR strain from one of two distinct lineages of the Newport serovar. Salmonella enterica subsp. enterica serovar Newport is common worldwide. Outbreak investigations and targeted studies have identified dairy cattle as the main reservoir this serotype. Antimicrobial resistance (Newport MDR-AmpC) is particularly problematic in this serotype, and the prevalence of Newport MDR-AmpC isolates from humans in the United States has increased from 0% during 1996-1997 to 26% in 2001. MDR strains have been recorded as resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides and tetracycline (ACSSuT) and many of these strains show intermediate or full resistance to third-generation cephalosporins, kanamycin, potentiated sulphonamides, and gentamicin. This group of Enterobactericiae have pathogenic characteristics and are one of the most common causes of enteric infections (food poisoning) worldwide. They were named after the scientist Dr. Daniel Salmon who isolated the first organism, Salmonella choleraesuis, from the intestine of a pig. The presence of several pathogenicity islands (PAIs) that encode various virulence factors allows Salmonella spp. to colonize and infect host organisms. There are two important PAIs, Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2) that encode two different type III secretion systems for the delivery of effector molecules into the host cell that result in internalization of the bacteria which then leads to systemic spread.