Query: NC_017160:3094768 Yersinia pestis D182038 chromosome, complete genome
Lineage: Yersinia pestis; Yersinia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: Specific virulence factors are encoded within pathogenicity islands (PAIs) that are required for the invasive phenotype associated with Yersinia infections. One key virulence plasmid contained by the three human-specific pathogens is pCD1/pYv, which encodes a type III secretion system for the delivery of virulence proteins that contribute to internalization into the host cell. It is the causative agent of plague (bubonic and pulmonary) a devastating disease which has killed millions worldwide. The organism can be transmitted from rats to humans through the bite of an infected flea or from human-to-human through the air during widespread infection. Yersinia pestis is an extremely pathogenic organism that requires very few numbers in order to cause disease, and is often lethal if left untreated. The organism is enteroinvasive, and can survive and propagate in macrophages prior to spreading systemically throughout the host. Yersinia pestis also contains a PAI on the chromosome that is similar to the SPI-2 PAI from Salmonella that allows intracellular survival in the organism.
Subject: NC_004631:1881214 Salmonella enterica subsp. enterica serovar Typhi Ty2, complete
Lineage: Salmonella enterica; Salmonella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This pathogenic strain of Salmonella typhi was isolated in the early 1970s. It contains no multidrug resistance plasmids and has been used for vaccine development. This serovar is a human-specific organism that causes the life-threatening illness Typhoid fever which is acquired by coming into contact with contaminated food or water. Annually, 17 million people are infected, with 600,000 fatalities, mostly in developing countries. It contains multiple fimbrial operons that may be used to create extracellular appendages for attachment and entry into host intestinal epithelial cells. Causes enteric infections. 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.