Prevalence and Types of Extended-Spectrum β-Lactamase-Producing Bacteria in Retail Seafood.

To assess prevalence and types of extended-spectrum β-lactamase (ESBL)-producing bacteria in retail seafood. A literature review was completed according to international guidelines for systematic reviews, except for being performed by a single reviewer. Kruskal-Wallis and Dunn tests were used to determine statistical differences between continents or seafood types. Among 12,277 hits, 42 publications from 2011 to 2023 were deemed relevant to the review's objectives. The median prevalence of ESBL-contaminated products was 19.4%. A significantly lower prevalence was observed in Europe ( = 0.006) and Africa ( = 0.004) compared to Asia. Amongst the 2053 isolates analyzed in the selected studies, 44.8% were ESBL-positive. The predominant type was CTX-M (93.6%), followed by TEM (6.7%) and SHV (5.0%). Only 32.6% and 18.5% of the CTX-M-positive isolates were typed to group and gene level, respectively. While group 1 (60.2%) was prevalent over group 9 (39.8%) among Enterobacterales, the opposite trend was observed in spp. (60.0% vs. 40.0%). Information at gene level was limited to Enterobacterales, where CTX-M-15 was the most prevalent (79.2%). On average, one in five seafood products sold at retail globally is contaminated with ESBL-producing Enterobacterales of clinical relevance. Our findings highlight a potential risk for consumers of raw seafood, especially in Asia.