Vibrios cholerae

A failure to turn off GTP-activated Ga has dire consequences. For example, in the disease cholera, cholera toxin produced by the bacterium Vibrio cholerae binds to Ga and prevents GTP hydrolysis, resulting in the continued excretion of sodium and water into the gut. 

Palmer, L. M., and Colwell, R. R. (1991). Detection of luciferase gene sequence in nonluminescent Vibrio cholerae by colony hybridization and polymerase chain reaction. Appl. Environ. Microbiol. 57 1286-1293. 

Some of the pathogens in Table 2, infect only humans (e.g., Vibrio cholerae. Salmonella typhi. Shigella dysenteriae, poliovirus, hepatitis A virus), whereas others, known as zoonotic, infect both humans and animals Salmonella no thypi. Shigella no dysenteriae, Campylobacter, enteropathogenic Escherichia coli such as for example the biotype 0157 H7, Cryptosporidium, etc.). The control of those that only infect humans is easier than the control of the zoonotic ones. Thus, some of them (S, typhi, S. dysenteriae, poliovirus, etc.) have practically been eradicated in many developed countries, whereas the eradication, and even the control below certain levels, of the zoonotic ones is a very difficult task. 

Viral replication, packaging and release. Drug Disc Today 1 388-397 Meindl P, Tuppy H (1969) 2-Deoxy-2,3-dehydrosialic acids. II. Competitive inhibition of Vibrio cholerae neuraminidase by 2-deoxy-2,3-dehydro-V-acyIneuraminic acids. Hoppe-Seyler s Z Physiol Chem 350 1088-1092... 

Interestingly, they report that E. coli, a normal inhabitant of the mammalian gastrointestinal tract, produces anhydro-TTX. Unidentified sodium channel blockers have also been detected in cultures of Vibrio cholerae an estuarine bacterium and human enteropathogen (54). 

Bordetellapertussis, Corynehacterium diphtheriae, Vibrio cholerae). This is, to a large extent, a reflection of their inability to combat that host s deeper defences. Survival at these sites is largely due to firm attachment to the epithelial cells. Such organisms manifest disease through the production and release of toxins (see below). 

In the gut, many pathogens adhere to the gut wall and produce their toxic effect via toxins which pervade the surrounding gut wall or enter the systemic circulation. Vibrio cholerae and some enteropathic E. coli strains localize on the gut wall and produce toxins which increase vascular permeability. The end result is a hypersecretion of isotonic fluids into the gut lumen, acute diarrhoea and consequent dehydration which may be fatal in juveniles and the elderly. In all these instances, binding to epithelial cells is not essential but increases permeation ofthe toxin and prolongs the presence of the pathogen. 

Killing. The proeess by which the live bacteria in the culture are killed and thus rendered harmless. Heat and disinfectants are employed. Heat and/or formalin are required to kill the cells of Bordetella pertussis used to make whooping-cough vaccines, and phenol is used to kill the Vibrio cholerae in cholera vaccine and the Salmonella typhi in typhoid vaeeine. 

Neuraminidase Vibrio cholerae Possible increase immuno-genicity of tumour cells 2.4.3... 

J. B. Guckert, M. A. Hood, and D. C. White, Phospholipid ester-linked fatty acid profile changes during nutrient deprivation of Vibrio cholerae increases in the irans/cis ratio and the proportions of cyclopropyl fatty acids, Appl. Environ. Microbiol. 52 794 (1986). 

Bacteria are likely precipitants in many other cases including Escherichia coli, Salmonella species, Shigella species, Vibrio cholerae, and Clostridium difficile. The term dysentery has often been used to describe some of these bacterial infections when associated with serious occurrences of bloody diarrhea. Additionally, acute diarrheal conditions can be prompted by parasites-protozoa such as Entamoeba histolytica, Microsporidium, Giardia lamblia, and Cryptosporidium parvum. Most of these infectious agents can be causes of traveler s diarrhea, a common malady alflicting travelers worldwide. It usually occurs during or just after travel subsequent to the ingestion of fecally-contaminated food or water. It has an abrupt onset but usually subsides within 2 to 3 days. 

Cholera, the first reportable disease, is endemic in South Asia, particularly in the Ganges delta region.2 The biotypes of Vibrio cholerae responsible for pandemics are serogroup 01 (El Tor) and serogroup 0139.16,17 Cholera can be transmitted by water or by food contaminated with contaminated water, particularly undercooked seafood. V. cholerae grows well in warm temperatures, causing marked seasonality in the incidence of cholera.2... 

The first of the haem uptake systems to be characterized at molecular level was that of Yersinia enterolitica, which closely resembles a typical siderophore uptake system (Stojiljkovic and Hantke, 1992, 1994), including a TonB-dependent outer membrane receptor for haem, a periplasmic binding protein, and a cytoplasmic membrane transport system. There also seems to be a protein that degrades haem and liberates haem iron within the cell. TonB-dependent outer membrane receptor proteins for haem have been cloned and sequenced from Shigella dysenteriae and E. coli (Mills and Payne, 1995 Torres and Payne, 1997), while in Vibrio cholera two genes are required for haem utilization, one an outer membrane receptor a second which may have a TonB-like function (Henderson and Payne, 1994). 

Vibrio cholerae 4.0/3828 (71) Epidemic and endemic fatal diarrheal disease... 

Clostridium perfringens E.coli 0157. H7 E.coli (enterotoxigenic) Listeria monocytogenes Salmonella spp. Shighella sonnei Vibrio cholerae Yersinia enterocoltica (Norovirus) ... 

Fig. 40. Simple lactoside analogues as surrogates for the more complex GML oligosaccharide ligand against the pentameric bacterial toxin from Vibrio cholerae 09...

Diarrhea Enteric infections Escherichia coli Cryptosporidium Shigella Vibrio cholerae Clostridium difficile Salmonella... 

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