Prevalence and Characterization of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Enterobacterales from Tunisian Seafood

Abstract

Aquaculture is a rapidly expanding sector in which it is important to monitor the occurrence of multi-drug resistant (MDR) bacteria. The presence of extended-spectrum β-lactamase (ESBL-) or carbapenemase-producing Enterobacterales is a commonly used indicator of the resistance burden in a given sector. In this study, 641 pieces of farmed fish (sea bream and sea bass), as well as 1075 Mediterranean clams, were analyzed. All ESBL- and carbapenemase-producing Enterobacterales collected were whole-genome sequenced. The proportion of ESBL-producing Enterobacterales was 1.4% in fish and 1.6% in clams, carried by Escherichia coli (n = 23) and Klebsiella pneumoniae (n = 4). The ESBL phenotype was exclusively due to the presence of blaCTX-M genes, the most frequent one being blaCTX-M-15. The blaCTX-M-1 gene was also identified in six E. coli, among which four were carried by IncI1/pST3 plasmids, possibly betraying an animal origin. Carbapenemases were absent in fish but identified in two K. pneumoniae isolates from clams (blaNDM-1 and blaOXA-48). Several sequence types (STs) identified were associated with human MDR clones such as E. coli ST131 and ST617, or K. pneumoniae ST307 and ST147. Our results might indicate that bacteria from hospital or farm effluents can reach the open sea and contaminate seafood and fish that are living or raised nearby. Therefore, monitoring the quality of water discharged to the sea and the presence of MDR bacteria in seafood is mandatory to ensure the quality of fishery products.

Prevalence of Extended-Spectrum β-Lactamases (ESBLs) Producing Aeromonas spp. Isolated from Lamellidens marginalis (Lamark, 1819) of Sewage-Fed Wetland: A Phenotypic and Genotypic Approach

“…A study from Taiwan [44] showed that 28% of the clinical isolates were resistant to an extended-spectrum cephalosporin. Our analysis suggests that bivalve mussels have the potential to act as reservoirs for multidrug-resistant bacteria, which is consistent with the findings of Sola et al [45]. This suggests that increased organic and inorganic contamination in sewage effluents may result in a high load of Aeromonas spp.…”

Occurrence of carbapenem-resistant hypervirulent Klebsiella pneumoniae in oysters in Egypt: a significant public health issue

“…Aquatic environments have been identified as reservoirs for antibiotic resistance due to the improper use and excessive administration of antibiotics for disease management [ 47 ]. Recent reports have underscored the emergence of carbapenem-resistant K. pneumoniae (CRKP), even in marine bivalves, posing a disturbing trend in antibiotic resistance [ 29 , 48 ]. Among the confirmed K. pneumoniae isolates tested against the carbapenem antibiotics group, two showed sensitivity, one exhibited intermediate resistance, and thirteen displayed carbapenem resistance.…”