Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water

Asellus aquaticus as a Potential Carrier of Escherichia coli and Other Coliform Bacteria into Drinking Water Distribution Systems

“…This was 700 times higher than the number of associated Klebsiella pneumoniae (MPN A. aquaticus −1 ), which was the coliform bacterium investigated in the study [21]. The only investigated A. aquaticus associated pathogen, Campylobacter jejuni , showed an even lower degree of association with A. aquaticus [21].…”

“…This was 700 times higher than the number of associated Klebsiella pneumoniae (MPN A. aquaticus −1 ), which was the coliform bacterium investigated in the study [21]. The only investigated A. aquaticus associated pathogen, Campylobacter jejuni , showed an even lower degree of association with A. aquaticus [21]. When expressed per mL A. aquaticus , HPC was also low (5.9 × 10 5 CFU·mL −1 A. aquaticus ) compared to microscopic crustaceans, on which bacterial numbers ranged between 9.7 × 10 7 and 5.6 × 10 8 CFU·mL −1 crustacean [27].…”

“…reached 7 × 10 4 ·copepod −1 [26] in spite of copepods being more than ten times smaller than asellids. More than 10 4 naturally occurring drinking water bacteria (HPC R2A agar 20 °C ) per A. aquaticus have been measured in drinking water samples [21] and A. aquaticus host symbiotic bacteria in the hepatopancreases which is not the case for all crustaceans [13]. Hence A. aquaticus are able to host bacteria but were not important carriers of E. coli or other coliform bacteria though A. aquaticus were present in surface water environments with high concentrations of faecal contaminants.…”

“…No distinction was made between adhering and internal bacteria, nor has this been studied in the available literature. Since detection by Colilert ® relies on an enzymatic reaction, pre-experiments were carried out as described by Christensen et al [21], establishing that grinded A. aquaticus did not influence the reaction. The pre-experiments also established that the absorbent tissue prevented bacteria from the water phase from being quantified together with the A. aquaticus associated bacteria.…”

On the way to identify microorganisms in drinking water distribution networks via DNA analysis of the gut content of freshwater isopods

“…Some recent reports have been published on the situation in the Netherlands (Van Lieverloo et al, 2004), Denmark (Christensen et al, 2011b(Christensen et al, , 2012 and Germany (Gunkel and Scheideler, 2011).…”