prevalence and molecular characteristics of vibrio species in pre ...

More documents

Recommendations

Info

20 D-Mannitol + + + + - + + + V + - ONPG - + + + - + + - + + - Voges- Proskauer + V - - - + - - - + - Y= yellow, G= green, NG= no or poor growth, nd= not done, V=variable among strains, R=resistant, S=susceptible V. alg=V. alginolyticus, V. cho=V. cholerae, V. flu=V. fluvialis, V. fur=V. furnissii, V. hol=V. hollisae, V. me=V. metschnikovii, V. mi=V. mimicus, V. parh=V. parahaemolyticus, V. vul=V. vulnificus, A. hy=A. hydrophilia, P. sh=P. shigelloides Currently, 72 species are included in the Vibrio genus and 12 species are commonly isolated in human patients. From these 12 species, V. cholera, V. parahaemolyticus and V. vulnificus are the most harmful to humans. Other Vibrio spp. isolated from humans are V. alginolyticus, V. fluvialis, V. mimicus, V. (Grimontia) holisae, V. (Photobacterium) damsel, V. furnssii, V. cincinnatiensis, V. harveyi, and V. metschnikovii. 2.7.3 Growth parameters of Vibrio spp. Table 7 shows the growth limiting factors of major human pathogenic Vibrio spp. Table 7: Growth limiting factors of Vibrio (FAO, 2003) Species Temperature o C pH aW NaCl (%) Min Max Min Min Max V. cholerae 10 37 5.0 0.97 8 V. parh 5 37 4.8 0.93 8-10 V. vulnificus 8 37 5.0 0.96 5 V. parh = V. parahaemolyticus
21 2.7.4 Genotypic characteristics of Vibrio Researchers have investigated the phenotypic and genotypic characterization of the Vibrio organism using new molecular technology based on the ribotyping and polymerase chain reaction technique such as amplified fragmented length polymorphism (AFLP), fluorescence in situ hybridization (FISH) or multi locus sequence typing (MLST) (Thompson et al., 2004). Identification of toxigenic genes and serogroups (Dalsgaard et al., 2001, Janssen et al., 1996, Raghunath et al., 2008), genetic diversity (Jiang et al., 2000, Sawabe et al., 2002, Zo et al., 2002), ecological interaction and relatedness of clinical and environmental isolates (Zo et al., 2002) of Vibrio has been carried out with the help of new techniques. Toxigenic Vibrio cholerae O1 samples from the aquatic environment and human intestines isolated from Bangladesh were analyzed by enterobacterial repetitive intergenic consensus sequence-PCR, optimized for profiling by using the fully sequenced V. cholerae E1 Tor N16961 genome. A study found a similar composition of environmental toxigenic V. cholerae and the V. cholerae that causes the endemic cholera. Authors conclude that the spatial and temporal fluctuation (seasonal fluctuations in the environment, introduction of new strain) in the composition of the toxigenic V. cholerae population in the aquatic environment can cause shifts in the dynamics of this disease (Zo et al., 2002). An investigation carried out by Jiang et al. (2000) detected V. cholerae isolates in Chesapeake Bay coastal waters. The genetic diversity analyzed by applying AFLP fingerprinting revealed the link between the shift of the genotype and environmental changes such as water temperature. MLST was developed recently and considered as most reliable molecular tool for the epidemiology. This method is based on the sequence analysis of housekeeping (HK) genes of the organism. Higher discriminatory power, accuracy and portability of the data, ease of performance, and reproducibility are major advantages of this method (Thompson et al., 2004). Nucleic acid sequences are stored in a public data base that can be easily accessed via internet (http://www.mlst.net or http://pubmlst.org) (González-Escalona et al., 2008). Scientist applied this method to determine the global epidemiology of bacterial pathogens. González-Escalona et al.
Page 1 and 2: 2.1 Shellfish culture CHAPTER II LI
Page 3 and 4: 7 constant over the years while cul
Page 5 and 6: 9 Pathogenic bacteria associated wi
Page 7 and 8: 11 Listeriosis, and other pathogens
Page 9 and 10: Coastal water Shrimp Bangladesh (Co
Page 11 and 12: Table 4: Cholera pandemics Pandemic
Page 13 and 14: 17 parahaemolyticus should be Kanag
Page 15: 19 2.7.2 Biochemical characteristic
Page 19 and 20: 23 Clinical strains of V. parahaemo
Page 21 and 22: 2.8 Human pathogenic Vibrio 2.8.1 V
Page 23 and 24: 27 Vibrio spp. display similar bioc
Page 25 and 26: 29 host and effluent from the conta
Page 27 and 28: 31 elimination of Edwardsiella tard
Page 29 and 30: A. Cooling and freezing 33 Rapid an
Page 31: 2.10.3 Consumer education 35 Consum

prevalence and molecular characteristics of vibrio species in pre ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?