Indicator bacteria in freshwater and marine molluscs

Abstract

The freshwater mussel Anodonta cygnea and four marine shellfish (mussels, Mytilus edulis; cockles, Cerastoderma edule ; clams, Mya arenaria ; Scrobicularia plana) from a total of six sites were surveyed for Escherichia coli, Clostridium perfringens, faecal streptococci, 25 and 37 ° C coliforms, 25 ° C and 37 ° C total viable numbers and fluorescent pseudomonads . The A . cygnea from an urban lake contained greater numbers of the faecal indicator bacteria than animals from a rural lake . There were also differences in the other bacterial counts and these were discussed with respect to bacterial parameter and animal characteristics . When freshwater mussels were transferred from the city site to the rural site for 24 h the load of faecal indicator bacteria was eliminated or significantly reduced . Other bacterial types took longer to become stabilised . Loss of indicator bacteria from Anodonta was also demonstrated using cleansing in the laboratory . Very high bacterial numbers were found in some marine molluscs notably Scrobicularia plana and most shellfish contained significant numbers of the three faecal indicator bacteria at every sampling occasion . The relationship between bacterial types was discussed and it was concluded that in both freshwater and marine animals the bacterial numbers were determined more by sampling site than by species of shellfish .

Uptake and persistence of human associatedEnterococcusin the musselMytilus edulis:relevance for faecal pollution source tracking

“…Several studies have shown that faecal bacteria can accumulate and persist in M. edulis (Al‐Jebouri and Trollope 1984; Trollope and Al‐salihi 1984; Doré and Lees 1995; Silverman et al. 1999; Hernroth et al.…”

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

“…Other workers concluded almost the same fluctuation of total viable counts in Iraqi rivers [12,21]. 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].…”

“…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].…”

“…ground waters [6]. Raw water quality can be assessed using various parameters particularly the bacterial indicators of biological pollution [7]. Chemical and physical factors affecting water quality have been utilized for evaluation of degree of pollution and these included oxygen biological demand, turbidity, electrical conductivity, temperature, and pH of waters under investi-gations [8][9][10].…”

Heterogeneity of bacterial communities within the zebra mussel (Dreissena polymorpha) in the Laurentian Great Lakes Basin

“…Bacterial communities associated with the zebra mussel have rarely been investigated and when studied, analysis involved whole mussel homogenate (Al-Jebouri and Trollope, 1984;Frischer et al, 2000;Selegean et al, 2001;Gu and Mitchell, 2002). Therefore, little is known about the differences in bacterial communities within the mussel's body.…”