Prevelance of total coliforms, faecal coliforms and <i>E. coli</i> in Rawalpindi vegetable markets

Abstract

Nutritional value of vegetables and high prices of meat and meat originated food compel common people to consume plant originated food particularly salad vegetables. Microbial population of vegetable surfaces contains a large number of pathogenic bacteria including members of Enterobactereace like Escherichia coli (E. coli). A survey was conducted in three major markets of Rawalpindi, Pakistan. Tomato, lettuce, cabbage and cucumber samples were collected from three shops of each market. Each vegetable was analysed as unwashed and washed for total coliforms, faecal coliforms and E. coli by FAO (Food Quality Manual). About two hundred and fifty E. coli isolates were preserved, serotyped for presence of O157 serotype. Total coliforms, faecal coliforms and E. coli count exceeded the permissible limits in most samples. The highest Total coliforms were associated with cabbage (3.78 log 10 cfu/g). Cucumber was the least contaminated by Total coliforms (2.15 log 10 cfu/g). E. coli was detected in tomato, lettuce, cucumber and cabbage. Washed samples showed reduced bacterial population. Seventy six isolates of E. coli were biochemically characterized and serotyped for O157 antigen. A majority of strains could not be identified by serotyping. These findings conclude with high potentially pathogenic microbial load on salad vegetables and urge for preventive action on priority basis.

The Use of TiO2 as a Disinfectant in Water Sanitation Applications

“…Within the range of bacteria evaluated for disinfection, priority is given to those that may present a public health problem, focusing on two groups: total and fecal coliforms. According to [76], the former group includes coliforms that are found in soil and surface water, particularly those that have been impaired by human or animal waste. Correspondingly, the latter group is made up of coliforms found in the intestine and feces of warm-blooded animals, with fecal coliforms being a subgroup of total coliforms.…”