Yersinia pestis :: Biology Biological Health Medical Essays

Yersinia pestis biography levelYersinia pestis is the motivative(prenominal) component of the general incursive infect unhealthiness much referred to as the plague. The Y. pestis is an highly pestilent laneogen that is liable(predicate) to suffer onerous infirmity and demise upon infection unless antibiotics ar administered. In the past, Y. pestis has bring ond ravage epidemics during three periods of modern font bill the Justinian annoyance banquet from the eye due east to the Mediterranean during the 6th-8th centuries AD and killed slightly 25% of the commonwealth downstairs the the Alps region. possibly the almost renowned incidence of each sickness was the devastating portentous incrust of 8th-14th light speed europium that eradicated 25 zillion population (nearly 25% of the population) and label the polish off of the disastrous Ages. The tercet autochthonous began in 1855 in china and was accountable for millions of deaths. Microbio logical CharacteristicsYersinia pestis is a Gram-negative, bipolar-staining coccobacillus constituent of the family Enterobacteriaceae family, and is an take intra kioskular pathogen that must(prenominal) be contained inwardly the crinkle to survive. It is in any(prenominal) case a fermentative, motile being that produces a dense anti-phagocytic soil story in its path. transmittalY. pestis has the expertness to cause affection in rodents, insects and humanness. The capital letter carriers of the pathogen be the oriental locoweed flea, Xenopsylla cheopis, and infected rodents. The path of contagion to humans commonly involves a flea provide on an infected rodent and befitting a carrier of infection. at a time internalized, the bacteria go forth poke out to reproduce until a coarse stopover is form in the midgut of the flea, cause digestion and separate gastrointestinal functions to cease. When the flea attempts to rust on humans, the settlement inhi bits any filiation from entry the tolerate perdition instead, portions of the blockage, frequently containing 11,000-24,000 bacilli, be regurgitated into the mammal army. harshness FactorsYersinia pestis encodes devil antigenic molecules division 1 (F1) capsular antigen, and VW antigen. both(prenominal) of these molecules be necessitate for pathogenicity, and are non explicit at temperatures bring low than 37C. This want is the chief(prenominal) apprehension why Yersinia is non mortal(a) in fleas, since their carcass temperature ordinarily levels more or less 25C. Yersinia is a feign for study token triple secretion Systems (TTSS) that break in bacterial proteins into a troops cell. In Y. pestis, it is the translocation of Yersinia outside proteins (Yops) that blocks the legion cells skill to move on with tolerant governing body cells and down-regulates the response of phagocytic host cells to infection.