Connectivity dynamics in Irish mudflats between microorganisms including Vibrio spp., common cockles Cerastoderma edule, and shorebirds

Abstract

Shellfish, including the key species the common cockle Cerastoderma edule, living and feeding in waters contaminated by infectious agents can accumulate them within their tissues. It is unknown if microbial pathogens and microparasites can subsequently be transmitted via concomitant predation to their consumers, including shorebirds. The objective of this study was to assess if pathogens associated with C. edule could be detected seasonally in the faeces of shorebirds that feed on C. edule and in the physical environment (sediment) in which C. edule reside, along the Irish and Celtic Seas. Two potentially pathogenic global groups, Vibrio and Haplosporidia, were detected in C. edule. Although Haplosporidia were not detected in the bird faeces nor in the sediment, identical strains of Vibrio splendidus were detected in C. edule and bird faecal samples at sites where the oystercatcher Haematopus ostralegus and other waders were observed to be feeding on cockles. Vibrio spp. prevalence was seasonal and increased in C. edule and bird faecal samples during the warmer months, possibly due to higher seawater temperatures that promote the replication of this bacteria. The sediment samples showed an overall higher prevalence of Vibrio spp. than the bird faecal and C. edule samples, and its detection remained consistently high through the sites and throughout the seasons, which further supports the role of the sediment as a Vibrio reservoir. Our findings shed light on the fact that not all pathogen groups are transmitted from prey to predator via feeding but bacteria such as V. splendidus can be. As most of the wading birds observed in this study are migratory, the results also indicate the potential for this bacterium to be dispersed over greater geographic distances, which will have consequences for areas where it may be introduced.

When Vibrios Take Flight: A Meta-analysis of Pathogenic Vibrios Species in Wild and Domestic Birds

“…One study examined the shared microbiota between wild Hooded Cranes (Grus monacha) and domestic geese ( Anser anser ) using Miseq – Grimontia hollisae was identified as a potential pathogen, but the total number of birds colonized was not reported [123]. A longitudinal microbiome study involving shorebirds off the coast of Cork, Ireland discovered Grimontia hollisae in fecal samples, however, the number of samples positive/examined was not enumerated [124]. Clinical signs or mortality were not reported from either study.…”

“…No study that tested for this pathogen reported clinical signs or a mortality event. Grimontia hollisae was rarely detected in birds, as we found only two studies, resulting in three study records, that searched for the pathogen in avian hosts [123, 124]. One study examined the shared microbiota between wild Hooded Cranes (Grus monacha) and domestic geese ( Anser anser ) using Miseq – Grimontia hollisae was identified as a potential pathogen, but the total number of birds colonized was not reported [123].…”

“…Uncategorized Vibrio spp. were reported from 14 studies [68,69,71,73,74,80,83,95,100,109,124,[127][128][129]. Two studies were associated with clinical signs and/or mortality events, however, these outbreaks were attributed to other causal pathogens [100,127].…”

Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China

“…This may be related to the environment in which these birds and primates and non-primate mammals live. These birds are wading birds whose feeding environment relies heavily on silt, which contains some fecal matter and some infectious Eimeria coccidia, thus making them susceptible to disease transmission [30]. Of course, it may also be due to birds being more susceptible to Eimeria, as Eimeria coccidia causes the most severe damage to poultry (belonging to birds).…”

Migratory Shorebird Gut Microbes are not Associated with Bivalve Prey in Monsoon Tropical Australia

“…Alongside whole bacterial microbiome data, we focused on detecting Vibrio species in the samples. Bacteria in the genus Vibrio include pathogenic and non-pathogenic taxa associated with human and wildlife diseases, and previous studies suggest that birds ingest potentially pathogenic vibrios and may spread them long distances [ 16 , 17 ].…”