E. coli infections and diseases can be prevented and controlled through the following ways: E. coli infections and diseases can be controlled by Washing of hands before and after cooking of foods, Avoiding cross contamination of food substances or stuffs; Constant keeping food in the refrigerator or to frozen; Ensuring that foods is kept at appropriate temperature;
Avoiding raw meat and poultry in the home; Ensuring that food substances are defrost on the counter; Ensuring that left over food materials and substance (Asia, 1999).2.7.4 Involvement of Escherichia coli with Snails
Snails appear to be passive carriers of gastroenteris and salmonella, demonstrate no clinical disease and can excrete Salmonella spp. without apparent trouble. The contamination of this organism derives from terrestrial sources and snail may serve as a vector for Salmonella species. (Metz, 1980; Minefe, 1986; Chattopadhyay, 2000). An outbreak of Salmonella Blockley infections following smoked eel consumption was described in Germany. The consumed eel came from four different local smoke houses, but could be traced back to snail farms in Italy (Fell, 2000). This outbreak indicates that eel may be a vector of Salmonella species infection and that the smoking process may not eliminate bacterial contamination from snail. Salmonella enterica serotype Paratyphi B var. Java phage type Dundee was isolated from the stool of a 14-month old boy who suffered from diarrhoea, vomiting, and fever for two days. The same isolate was identified from the water of home snail (Senanayake, 2004). Snail and fish was the vector of E.coli. in this case. Unusual E.coli species serotypes were found in eight of 100 tropical aquariums sampled in Wales (Sanyal, 1987). In a Canadian outbreak of Salm. enterica serotype Paratyphi B linked to aquariums, five of seven cases were in children aged less than 10 years (Gaulin, 2002). Another outbreak caused by multidrug-resistant Salm. enterica subsp. enterica serotype Typhimurium DT104L was described in Singapore (Ling, 2002). Consumption of imported anchovy was found to be the cause of infection.
2.7.5 Mode of transmission of Escherichia coli
E. coli infections and diseases can be transmitted through the following ways; By not washing of hands before and after cooking prevent the transmission of E. coli infections and diseases; By cross contamination of food substances prevent the transmission of E. coli infections and diseases; By not keeping foods in refrigerator prevent the transmission of E. coli infections and diseases; Not ensuring that foods are kept at appropriate temperature prevents the transmission of E. coli infections and diseases; Constant using of raw snail meat and poultry in food preparation(Gaulin, 2002).
2.7.6 Pathogenesis of Escherichia coli
Optimum growth of E. coli occurs at 37 °C (98.6 °F), but some laboratory strains can multiply at temperatures of up to 49 °C (Senanayake, 2004). Growth can be driven by aerobic or anaerobic respiration, using a large variety of redox pairs, including the oxidation of pyruvic acid, formic acid, hydrogen, and amino acids, and the reduction of substrates such as oxygen, nitrate, fumarate, dimethyl sulfoxide, and trimethylamine N-oxide (Senanayake, 2004). E. coli can live on a wide variety of substrates and uses mixed-acid fermentation in anaerobic conditions, producing lactate, succinate, ethanol, acetate, and carbon dioxide. Since many pathways in mixed-acid fermentation produce hydrogen gas, these pathways require the levels of hydrogen to be low, as is the case when E. coli lives together with hydrogen-consuming organisms, such as methanogens or sulphate-reducing bacteria (Groopman, 2008).
2.7.7 Klebsiella pneumonia
Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. Although found in the normal flora of the mouth, skin, and intestines (Senanayake, 2004). It can cause destructive changes to human and animal lungs if aspirated (inhaled), specifically to the alveoli (in the lungs) resulting in bloody sputum. In the clinical setting, it is the most significant member of the Klebsiella genus of Enterobacteriaceae. K oxytoca and K rhinoscleromatis have also been demonstrated in human clinical specimens. In recent years, klebsiellae have become important pathogens in nosocomial infections. It naturally occurs in the soil, and about 30% of strains can fix nitrogen in anaerobic conditions (Chanishvili, 2012). As a free-living diazotroph, its nitrogen fixation system has been much-studied, and is of agricultural interest, as K. pneumoniae has been demonstrated to increase crop yields in agricultural conditions. Members of the Klebsiella genus typically express two types of antigens on their cell surfaces. The first, O antigen, is a component of the lipopolysaccharide (LPS), of which 9 varieties exist. The second is K antigen, a capsular polysaccharide with more than 80 varieties. Both contribute to pathogenicity and form the basis for serogrouping. Klebsiella pneumonia is one of the most important food-borne pathogens which are indication of sewage contamination and it is found to be associated with number of non-human hosts of diseases (Winfield and Groisman, 2003). It has been reported to survive and persist in the aquatic environment. Klebsiella pneumonia has been detected in periwinkles from different creats (Adebayo-Tayo. 2006), in the gut of tilapia and crab (Iyer and Shrivastava 1989; Ogbondeminu 1993) and causes new born meningitis and infantile diarrhea. The presence of Klebsiella pneumonia is an indication of serious contamination. Klebsiella pneumonia has been implicated in human infections like pharyngities, scarlet fever and pneumonia. Klebsiella pneumonia is causative agents of illnesses like pneumonia in human who are the only reservoir of these organisms (Nester et al., 1995).
2.7.8 Klebsiella pneumonia Morphology
Klebsiella pneumoniae is a Gram-negative, nonmotile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. Although found in the normal flora of the mouth, skin, and intestines (Chanishvili, 2012). It can cause destructive changes to human and animal lungs if aspirated (inhaled), specifically to the alveoli (in the lungs) resulting in bloody sputum. In the clinical setting, it is the most significant member of the Klebsiella genus of Enterobacteriaceae. K oxytoca and K rhinoscleromatis have also been demonstrated in human clinical specimens (Chanishvili, 2012). In recent years, klebsiellae have become important pathogens in nosocomial infections. It naturally occurs in the soil, and about 30 % of strains can fix nitrogen in anaerobic conditions (Chanishvili, 2012). As a free-living diazotroph, its nitrogen fixation system has been much-studied, and is of agricultural interest, as K. pneumoniae has been demonstrated to increase crop yields in agricultural conditions.[3] Members of the Klebsiella genus typically express two types of antigens on their cell surfaces. The first, O antigen, is a component of the lipopolysaccharide (LPS), of which 9 varieties exist. The second is K antigen, a capsular polysaccharide with more than 80 varieties.[4] Both contribute to pathogenicity and form the basis for serogrouping. It is closely related to K. oxytoca from which it is distinguished by being indole-negative and by its ability to grow on both melezitose and 3-hydroxybutyrate.
2.8 Epidemiology
When dealing with hospital-acquired bacterial infections caused by K. pneumoniae can arise in different parts of the body and in different forms of illness depending on transmission. K. pneumoniae is responsible for 6-17 % of UTI’s, 7-14 % of pneumonia, 4-15 % of septicemia, 2-4 % of wound infections, 4-17 nosocomial infections in intensive care units, and 3-20 % of all neonatal septicemia cases. All of these cases rank within at least the top 11 in comparison to all other bacterial pathogens. In the United States, people who suffer from alcoholism make up 66 % of people affected by community-acquired pneumonia. K. pneumoniae is now among the top 8 pathogens in hospitals and is a rising issue among hospitals all around the world due to antibiotc resistance. In humans, K. pneumoniae resides in the nasopharynx and in the intestinal tract. Since gram-negative bacteria do not have good growth on human skin, they are rarely found there in comparison to internal parts of the body. Reported carrier rates are quire the opposite of this fact, when in a hospital environment. Carriers rated in hospitalized patients were 19 % in the pharynx, 77 % in the stool, and 42 % on the hands. Even hospital employees had elevated rates of carriage to K. pneumoniae. These findings were linked to the over usage of broad-spectrum antibiotics rather than delivery of care (Lin, 2013). In 2011, an investivation of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae was conducted in hospitals among patient with short and long-term stays. Over a 1-year period, KPC-producing Enterobacteriaceae was found throughout 4 counties in Indiana and Illinois. The source of the problem was found to be within long-term facilities and patients (Castinel et al., 2007). KPC has been found in a total of 44 states thus far (Tang et al., 2015). 14 % of bacteremia cases are because by K. pneumoniae, which places it in second place next to Escherichia coli for origins of gram-negative sepsis. Outbreaks of neonatal septicemia and K. pneumoniae can be found worldwide. In Israel, a number of hospital facilities reported increases in KPC-producing Enterobacteriaceae beginning in 2006, while the first case in the United States was reported in 2001 (Castinel et al., 2007).
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