Influence of the copepod Mesocyclops longisetus (Crustacea: Cyclopidae) on the survival of Vibrio cholerae O1 in fresh water

Abstract

In an experimental microcosm, an analysis was performed of the influence exerted by freshwater Mesocyclops longisetus copepods on the survival of Vibrio cholerae O1 serovar Inaba. In the State of Ceará, copepods are used in the control of Aedes aegypti larvae. The system consisted of water with a salinity of 0.27 per 10,000 habitants and pH 7.5, which after sterilizing filtration was distributed into seven flasks with a volume of 400 ml; in each of six flasks, 10 live copepods were inoculated along with 1 ml of an 8-hour culture of Vibrio cholerae O1 at 37oC in Alkaline Peptone Water, resulting in a concentration of 3.80x10(4) colony-forming units. The control flask contained only the water with the same bacterial suspension. The system was maintained for six days at room temperature (25-28oC), and daily duplicate counts were performed in TCBS Agar. Results confirmed a clear association between Vibrio cholerae O1 and the live copepods, based on survival of the bacteria at compatible levels with the initial inoculation until the sixth day of the analysis.

Vibrio cholerae O1 em amostras de ambientes aquáticos e de alimentos analisados no Estado de Pernambuco, Brasil

“…2) Elevada umidade absoluta. Sem dúvida que outros parâmetros também estão associados ao processo, como o número excessivo de excretores fecais de V. cholerae O 1 na fase epidêmica, contaminando ecossistemas aquáticos, onde o fito e zooplanctons, como certas algas, possibilitariam a sobrevivência e multiplicação da bactéria no período silente (Islam et al, 1993(Islam et al, , 1994Araújo et al, 1996).…”

Marine Copepods as a Microbiome Hotspot: Revealing Their Interactions and Biotechnological Applications

“…Araújo et al [79] examined the influence of the copepod Mesocyclops longisetus on the survival of V. cholerae O1 serovar Inaba in freshwater. The study confirmed a clear association between V. cholerae O1 and live copepods, as the bacteria survived at compatible levels with the initial inoculation for six days in the presence of copepods.…”

Parasites, pathogens, and other symbionts of copepods

“…in estuarine and coastal environments [60], including the human pathogens V. parahaemolyticus, V. alginolyticus, V. vulnificus, and V. cholerae [61,62]. The adhesion of V. cholerae to live copepods has been demonstrated to extend its survival and culturability in both marine and fresh water when compared to adhesion to dead copepods, or free-living cells [63], suggesting that copepods may function as environmental reservoirs for the pathogen [64]. The pathogenic impact of associations with Vibrio spp.…”