The Escherichia coli Content of Mytilus edulis from Analysis of Whole Tissue or Digestive Tract

Abstract

The dissected digestive tract of edible mussels from two sites was examined for Escherichia coli and the counts compared with those from the total tissue of parallel mussel samples. The method using 4 x 1 ml pour plates was preferred to the 1 x 4 ml pour plate or to the 2 x 0.2 ml spread plates. Counts from the digestive tract were up to sixfold higher than parallel counts using total tissue. Digestive tract inoculum also produced amplified Esch. coli detection when lightly polluted mussels were examined by the semi‐quantitative percentage‐clean technique. It was concluded that dissection of the bacteriologically rich digestive tract significantly increases the sensitivity of Esch. coli detection and has application in environmental assay procedures using mussels or other filter‐feeding molluscs. Significant differences in the frequency of Esch. coli biotypes from the two mussel locations could be related to small differences in the pollution regimes at these two sites.

An Assessment of Biological Pollution in Certain Sector of Lower AL-Zab and River Tigris Waters Using Bacterial Indicators and Related Factors in Iraq

“…Cold weather as well as availability of organic matter are playing major roles in survival and presence of heterotrophic bacteria [7]. Furthermore, total coliforms is considered as an indicator for long-term water pollution [1]. The present study showed that the total coliforms were different according to sites of collection and the highest number was recorded in July which was almost 1023/100 ml ( Table 6).…”

“…This situation will increase the risk of water pollution as the rainfalls will clean out all pollutants towards the rivers. This is one of the major causes of increased numbers and types of bacterial indicators in water bodies [1,7].…”

“…All water samples were bacteriologically investigated for total viable counts (TVC, s), total coliforms (TC) and fecal coliforms (FC) using the conventional methods [1] and the most probable number techniques [14].…”

“…Fresh water bodies particularly rivers always considered as a main source of drinking and relevant human uses for maintenance of life. These natural water bodies usually under stress of environmental pollution including chemical, physical and biological aspects that might turn the nature of these waters to be risky for human beings uses [1][2][3][4][5]. Environmental stress as well as human population growth associated with an increased industrial and civilian activities can all cause a damage for the natural water quality that might be necessary for human needs which lead to continuous environmental survey and assessment to reveal the degree of pollution impact particularly on raw water sources like rivers, lakes, springs and deep wells waters i.e.…”

Indicator bacteria in freshwater and marine molluscs

“…Previous work with mussels from the West Pier and Mumbles sites (Al-Jebouri & Trollope, 1978 ;Al-Jebouri, 1980) showed the presence in these samples of Shigella dysenteriae, Yersiniaenterocolitica, Klebsiellapneumoniae, Enterobacter cloacae and Serratia sp . There are outfalls discharging sewage effluents near these shore sites and mussel samples from Mumbles which were the subject of a recent report by us on E. coli content (Al-Jebouri & Trollope, 1981), concurrently yielded the food poisoning organism Salmonella hadar (unpubl . results) .…”