Bacterial flora of the schistosome vector snail Biomphalaria glabrata

Abstract

The aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail Biomphalaria glabrata was examined. Internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. The numerically predominant bacterial genera in individual snails included Pseudomonas, Acinetobacter, Aeromonas, Vibrio, and several members of the Enterobacteriaceae. Enterobacteriaceae seldom predominated in laboratory colonies. Our data suggest that Vibrio extorquens and a Pasteurella sp. tend to predominate in high-bacterial-density snails. These snails may be compromised and may harbor opportunistic snail pathogens. Pak plastic bags (Nasco, Inc., Fort Atkinson, Wis.). Sampling from aquarium snail colonies. Laboratory snail colonies were derived from the NIH-AID albino strain of Puerto Rican B. glabrata or from wild B. glabrata collected in St. Lucia and Guadeloupe. These snails were reared in 10or 15-gallon (37.

Characterization of the bacterial microbiota of Biomphalaria glabrata (Say, 1818) (Mollusca: Gastropoda) from Brazil

“…Our results showed similarities to those of Ducklow et al (1979). These authors analysed specimens of B. glabrata from Puerto Rico, Saint Lucia and Guadalupe (Caribbean islands) and observed that Aeromonas sp.…”

“…This may be related to the presence of the genus Aeromonas in aquatic environments (Koneman and Winn 2006). Although Ducklow et al (1979) reported that Enterobacter sp. was found only in the wild groups of B. glabrata, this study detected E. cloacae in both groups, while predominating in the wild group.…”

“…Enterobacter cloacae is one of the species most commonly found in clinical samples, and it is part of the enteric commensal microbiota of humans (Koneman and Winn 2006), thus explaining the fact that it is predominantly found among snails of the wild group when their environment is contaminated by human faeces. In this work, the technique currently used for microbiological analysis, incubation at 37°C for 24 h, was applied, while Ducklow et al (1979) incubated bacteria for a period of 1 week at room temperature. Despite being a different methodology, the results showed similarity, probably because bacteria found in both studies are mesophilic, that is grow at temperatures between 25 and 40°C.…”

“…In the literature, there are only a few studies on the microbiota of molluscs, such as Helix pomatia ( Svec et al 2002;Charrier et al 2006;Villena et al 2010), Cornu aspersum (Charrier et al 2006), Hirudo medicinalis (Graf 1999) and Biomphalaria glabrata (Ducklow et al 1979).…”

Save your host, save yourself? Caste‐ratio adjustment in a parasite with division of labor and snail host survival following shell damage

“…It is thus possible that these nonreproductive morphs fulfill additional roles in the colony. For example, parasite colonies as well as their molluscan hosts are likely to face repeated bacterial or fungal infections (Bayne, 1983;Ducklow, Boyle, Maugel, Strong, & Mitchell, 1979;van der Knaap & Loker, 1990;Morley, 2010); soldier rediae might play a "cleaning" role in the defense against such microorganisms, as documented in social insects (Lloyd & Poulin, 2012, 2014aMouritsen & Andersen, 2017;Turnbull et al, 2012). Since trematode infection can suppress host immune defenses, the risk of secondary infection by pathogens should be increased (Bayne, 1983;Iakovleva, Shaposhnikova, & Gorbushin, 2006;Loker & Adema, 1995;Walker, 1979Walker, , 2006.…”