Introduction to microbiologyPaper on pathogensVibrio choleraeNazarbayev UniversityTaxonomy and morphologyVibrio cholerae is a gram-negative bacterium that is the etiological agent of the diarrheal disease cholera. Vibrio cholerae is a member of the Vibrionaceae family, which is a facultative anaerobe and is capable of respiratory and fermentative metabolism. It does not form spores and its motility is due to the single polar flagellum. Vibrios are highly halophilic and are very sensitive to low pH. (Nair, n.d.)These bacteria belong to the O antigenic group and O group 1 (O1) strains cause cholera. O1 strains are divided into two biotypes, classic and El Tor, and two main serotypes, Inaba and Ogawa. The other strains, other than O1, are called non-O1 strains which do not have the potential to cause epidemics. However, the new V.cholerae 0139 variant evolved from serogroup O1 to a non-O1 serogroup by horizontal gene transfer. V. cholerae O1 and O139 are currently believed to be the only serogroups causing epidemic cholera, characterized by severe watery diarrhea. (Formadi, 2007)History and EpidemiologyThe history of cholera begins in 1817 when the first epidemic was reported in India and then cholera spread outside the Indian subcontinent along trade routes to the west leading to the first pandemic. Since then, seven pandemics have occurred around the world. In 1961 the last one occurred in Indonesia and then spread to the Indian subcontinent and the Middle East, then moved to Africa in the 1970s and reached South America in the early 1990s. John Snow's epidemiological study in 1854 demonstrated the correlation between cholera and drinking contaminated water. (Sack, etc., 2004) Later...... half of the article......Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 24. Available from: http://www.ncbi.nlm.nih.gov/books/NBK8407/Formadi H. 2007. Vibrio cholera. Retrieved from: http://ci.vbi.vt.edu/pathinfo/pathogens/V_cholerae_2.htmlNair G. and Vibrio cholerae. World Health Organization. Guidelines for drinking water quality. Retrieved from: http://www.who.int/water_sanitation_health/dwq/admicrob6.pdfReidl J. and Klose K. 2002. Vibrio cholerae and cholera: out of the water and in the host. FEMS Microbiology Reviews 26, 125-139. Retrieved from: http://ezproxy.library.nu.edu.kz:2126/doi/10.1111/j.1574-6976.2002.tb00605.x/pdfSack D., Sack R., Nair G., and Siddique A. Cholera. 2004. Lancet, 363(9404), 223-233. Retrieved from: http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=4a213450-0d66-48ab-aee8-ba80898fa889%40sessionmgr12&vid=2&hid=121