Virulence and antimicrobial-resistance of shiga toxin-producing E. coli (STEC) Isolated from edible shellfish and its public health significance

Abstract

Shiga toxin-producing E. coli (STEC) are an important cause of foodborne illness in humans with infections ranging from mild non-bloody diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). This study aimed to investigate the distribution of STEC in shellfish from coastal shores of Lake Timsah in Ismailia Governorate, Egypt and its probable hazard to seafood consumers. Samples from the external surface and tissues of shrimp (n = 45), crabs (n = 45), and oysters (n = 45) batches were examined bacteriologically for the presence of STEC and tested for their antibiotic sensitivity. Moreover, occurrence of virulence genes was determined via detection of stx1, stx2 and eaeA genes using PCR. Overall, E. coli and presumptive STEC isolates (from CHROMagar) were identified from the surface (55.6 and 5.9%) and tissues (42.2 and 8.9%) of the examined shellfish batches, respectively. Five STEC isolates had been confirmed and found belonging to O26:H11, O125:H6, O146:H21, and O159 serogroups, those were 4 isolates from tissues of the three shellfish species and one isolate from the crab surface. The STEC isolates were multi-drug resistant, showing complete resistance to; penicillins, amoxycillin/clavulanic acid, colistin, fosfomycin, ceftriaxone, ciprofloxacin, and tetracycline, however, they were sensitive to gentamycin except O159 serogroup. The current study revealed low level of contamination of shellfish from coastal shores of Lake Timsah with STEC, however, it also highlights the extreme level of antimicrobial resistance exhibited by the presumptive and confirmed STEC isolates which is very hazardous for seafood consumers in the study area.

Clinical and public health implications of increasing notifications of LEE-negative Shiga toxin-producing Escherichia coli in England, 2014–2022

“…CC25 exhibits less pronounced seasonality and, again, this may reflect bespoke source and/or transmission routes specific to this type. Other studies have reported an association between isolates belonging to CC25 and prevalence in the ovine reservoir, whereas CC442 has a wider host range [29, 43–46, 48–51, 55]. However, even if this association was confirmed, it is unclear how this might impact on seasonality patterns.…”

“…Travel abroad was during the pandemic but based on available data the proportion of cases reporting travel were similar for CC33 and CC442. Previous studies have shown that CC442 may be associated with colonisation of a broad range of animal hosts and may be ubiquitous in the environment [29,[43][44][45][46]55]. Survival in the environment and persistence in the animal reservoir and the food chain have been linked to the presence of genes conferring resistance to tellurite [56,57].…”

Structural basis to identify a target site in Shiga toxin for the inhibitor discovery against growth of Shiga toxin-producing E. coli

“…STEC poses health risks to animal reservoirs and food products with respect to easy transmission, causing outbreaks, and transferring resistance genes to Qabili et al 2022;Carter et al 2023;El-Bastawisy et al 2023). Therefore, prevention of STEC infection must be strengthened to avoid the spread of STEC.…”

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

“…Furthermore, Enterobacteriaceae regroups important seafood-borne pathogens, and include genera like Escherichia [ 23 , 24 ], Shigella which was reported in Japan [ 25 ], Salmonella [ 26 , 27 , 28 , 29 , 30 , 31 ] and Klebsiella in Portugal [ 32 ], Tunisia [ 33 ] and Italy [ 34 ], which have drawn attention to their health threats and their contribution to the spread of antibiotic resistance in the environment ( Figure 1 and Supplementary Table S1 ).…”