Wednesday, 10 May 2017


Prealence of Entric Bacteria - Distant Library

1.1 Background of the Study

Snail is a common name which is applied to most of the members of the molluscan class gastropoda that have coiled shells in the adult stage (Fredericks, 2010). When the word is used in its most general sense, it includes sea Snails, land snails and freshwater snails. The word snail without any qualifier is however more often applied to land snails than to those from the sea or freshwater. However, some species of snails called aquarium snail are often found in the aquatic habitat with a coiled shell (Fredericks, 2010). 
Human infections caused by pathogens transmitted from aquarium snails or the aquatic environment are quite common depending on the season, patients’ contact with aquarium snails and related environment, dietary habits and the immune system status of the exposed individual. They are often bacterial species facultatively pathogenic for both aquarium snails and man. The infection source may be aquarium snails kept either for food or as a hobby (Acha and Szyfres, 2003). Thorough microbiological examinations are the prerequisites for correct diagnosis.
However, quantification of the occurrence of these diseases is difficult because many cases, typically gastrointestinal illness, go unreported; the symptoms usually do not last long and are self-limiting in apparently healthy people (Acha and Szyfres, 2003). It can be extremely difficult to detect certain in vitro slow growing causative agents of diseases such as those of Mycobacterium infections or infections caused by anaerobic pathogens. Mycobacterial infections are quite misdiagnosed with subsequent inappropriate therapy (Kern et al., 1999; Harth et al., 1994; Ryan and Bryant, 1997). Consequently, the disease can last for years (Ang et al., 2000). 
The bacteria load of enterococci present in snail is reasonably high, the bacteria flora in each of the snail sample range from 5-8 organisms/g. and are capable of causing health risk (Giaccone, 2012). An infective dose of up to 104 cfu-g especially of Salmonella is dangerous for humans when consumed via contaminated snail food; (Giaccone, 2012). It will be unhealthy for consumers to eat snail meat that is not properly cooked first and dried since it is known that E.coli and Klebsiella species and Salmonella species survive in dry products (Urabe, 2008). Recent study shows that E. coli presented the highest volume of enterobacteria organism present in snail. (Sprosten, 2006). These organisms of the family Enterobactericaea are found in the intestinal tracts of humans and animals in the soil and can be pathogenic to man. The results suggest that contamination of snail with fecal material, feeding on decaying matter, fecal contaminations of water, sell in the open market without covering them, poor handing are several factors that contribute to snail being carrier of enterobacteria organism (WHO, 2007). 
The association of E. coli and Klebsiella pneumonia with aquarium snails may also have public health significance and this fact indicate that aquarium could be another source of nosocomial infections (WHO, 2007). These pathogenic organisms isolated from the four markets such as Abakpa main market, Ekeaba market, Ahia ofuru market and Abakaliki main market visited have serious health implication to man. The risk of food borne illness is on the increase and the needs to provide effective way of managing this condition is of immerse significance. In the opinion of FDA (2011) which reported that heat application (90C for 10 minutes) is an effective way of eliminating pathogens from food.  Snail meat which contain high quality food that is rich in protein (low in fats,) and a good source of iron, that is, 3.5 mg/100 g (USDA, 2006). The comparative nutritive value of snail meat to some animal protein sources have been studied by some researchers. In an instance, the protein contents of 88.37, 82.42 and 92.75 % were discovered in snail, pork and beef respectively (Imevbore and Ademosun, 1988). With a fat content of only 1.3 % and iron content of 12.2 mg/100 g in edible carcass, the nutritive value of snails is reported to be comparable to that of domestic livestock. It is estimated that snail is 15% protein, 2.4% fat and about 80% water (Saldanha et al., 2001).  A study on a snail species in Brazil estimated that 75% of the fat in snail is unsaturated fatty acids. That is 57% polyunsaturated fatty acids, 15.5% of monounsaturated fatty acids and 23.25% of saturated fatty acids (Su et al., 2004). However, it can be easily contaminated by pathogens and serve as vehicle of transferring infectious agents to consumers. Kirkan et al. (2006) reported the presence of E.coli  in fresh aquarium snail sample which notably could have been contaminants from soil. So, despite rich nutritional values of snail, the involvement of the mollusks in general in the transmission of infection mostly as secondary host for pathogens makes it necessary to study the microbiology of the resident snail without leaving their nutritive values behind.
Significant numbers of aquarium snails are sold to the public and if carrying E.coli and Klebsiella species, these snails may present a public health risk similar to that presented by the aquarium turtles. It was reported that food safety and public health officials attribute a rise in the incidence of food borne illness to changes in demographics and consumer life style that affect the way food is prepared and stored (Collins, 1997). The objective of this study is to evaluate the prevalence of enteric bacteria (E.coli and Klebsiella species) implicated with fresh water aquarium snails like Achatina achatina when consumed if poorly cooked.  

1.2 Aim 

This project therefore is aimed at finding prevalence of enteric bacteria (E.coli and Klebsiella species) implicated with fresh water aquarium snails like Achatina achatina in Abakaliki metropolis. 
1.3 Specific Objectives 
The specific objectives of this project work includes
Isolation and identification of bacteria associated with aquarium snails
To determine the prevalence E.coli and Klebsiella species of bacteria in Achatina achatina snail species.

1.4 Scope of the Study 

This work is limited to the four markets in Abakaliki metropolis and focuses on the prevalence of enteric bacteria in aquarium snail within Abakaliki Metropolis of Ebonyi State. 

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