First Data on Campylobacter spp. Presence in Shellfish in Croatia

Abstract

This study aimed to assess the presence of thermotolerant Campylobacter spp., as one of the most important foodborne zoonotic pathogens, in three shellfish species: mussels (Mytilus galloprovincialis), oysters (Ostrea edulis) and queen scallops (Aequipecten opercularis). The samples were collected from nine locations in the Istrian aquatory, Croatia. Isolation of Campylobacter was done according to standard ISO method, and species were identified using multiplex PCR. Isolates identified as C. jejuni and C. lari were genotyped using multilocus sequence typing (MLST) to determine the potential source of contamination. Among 108 examined samples of bivalve molluscs, mussels dominated and were the only ones found positive for the presence of Campylobacter (25.6%). In total, 19 C. lari and 1 C. jejuni strains were isolated. C. lari isolates found in this study belong to 13 sequence types (STs), and 9 of them are newly described in this paper. Two out of the four previously described C. lari STs that were found in this study were previously found in human stool. The only C. jejuni isolate was found to be sequence type 1268, which belongs to ST-1275 clonal complex that is almost exclusively found in seabirds and can sporadically cause infection in humans. Regarding the obtained results, introducing surveillance of thermotolerant Campylobacter in shellfish in the Republic of Croatia is advised as an improvement for public health safety.

A Comprehensive Review for the Surveillance of Human Pathogenic Microorganisms in Shellfish

“…Similarly, Campylobacter bacteria share the spotlight with Salmonella as major causes of foodborne illness and can also be found in shellfish, suggesting contamination from environmental sources like water and bird excreta. They encompass species such as C. jejuni , which is associated with poultry and bovines, playing a prominent role in human infections; C. coli , linked to poultry and pork; and C. lari , which is a more recent group [ 19 , 35 , 36 , 37 , 38 ]. Recent studies showed that C. lari is particularly associated with shellfish contamination [ 36 , 39 ].…”

“…They encompass species such as C. jejuni , which is associated with poultry and bovines, playing a prominent role in human infections; C. coli , linked to poultry and pork; and C. lari , which is a more recent group [ 19 , 35 , 36 , 37 , 38 ]. Recent studies showed that C. lari is particularly associated with shellfish contamination [ 36 , 39 ]. The risk of infection from the consumption of raw shellfish was estimated to be 5–20% for mussels and 2–10% for oysters [ 35 ].…”

Genetic Diversity and Resistome Analysis of Campylobacter lari Isolated from Gulls in Croatia

“…Additionally, in this study, we aim to compare the phenotypic and genotypic resistances of C. lari strains. In Croatia, C. lari has only been studied in shellfish [ 24 ], and in general, it is still under-researched especially in wildlife; therefore, this is the first study conducted on gulls.…”