ZenToks Publication

Chapter 1

Extended-Spectrum β -lactamase-producing Escherichia coli in seafood and the environment: An emerging microbial challenge

Abstract/Preface

The ability of bacteria to resist antimicrobial agents has become a significant challenge in the contemporary world. Infections caused by antibiotic-resistant bacteria can compromise the efficacy of antimicrobial chemotherapy, leading to treatment failure and increased morbidity and mortality. Although some bacteria have the intrinsic ability to tolerate one or more drugs, resistance to multiple, clinically important antibiotics is due to the acquisition of multiple resistance genes through horizontal gene transfer (HGT). Among various classes of antibiotics, beta-lactam antibiotics have been effectively used to combat Gramnegative bacterial infections for decades. Escherichia coli, a significant human pathogen, has developed various mechanisms to resist β-lactam antibiotics, the most notable of which is the production of extended-spectrum β-lactamase (ESBL) enzymes that hydrolyze third-generation cephalosporins, such as cefotaxime and ceftazidime, as well as the monobactams. Although carbapenems are the drugs of choice for treating ESBL producers, the emergence of carbapenem-resistant Enterobacterales (CRE) has become a serious concern. The ESBL enzymes are very diverse, grouped into various families. SHV, TEM, CTX-M, and OXA are some of the common examples of ESBL types widely present in Enterobacterales, and the genes encoding these reside on mobile genetic elements, which allow their rapid dissemination. The isolation of ESBL-producing E. coli has been reported from diverse food including seafood and food production environments, emphasizing the significance of the ”One Health” approach in controlling the spread of multidrug-resistant bacteria in the food chain.