Antimicrobial Resistance of Extended-SpectrumCephalosporins and Fluoroquinolones in Salmonella spp.:Mechanism of Resistance and Epidemiology

Narong Nuanmuang, Aksarakorn Kummasook


Salmonella is a pathogen responsible for salmonellosis, a world-wide public health concern. Most infections from this microbe are the results of ingestion of contaminated food. Treatment with drugs, such as cephalosporins or fluoroquinolones is recommended for infections when severe diarrhea is a symptom. Recently, however, there are several reports of Salmonella antimicrobial resistance to these two popular treatments. Cephalosporin resistance is usually due to the production of β-lactamases such as CTX-M, TEM, OXA and SHV etc. The β-lactam ring can be broken by those β-lactamases leading to the inhibition of antibiotic activity. There are several mechanisms of fluoroquinolones resistance, including 1) mutation of DNA gyrase and topoisomerase IV; 2) production of enzymes for hydrolyzing drugs, such as aminoglycoside acetyltransferase (AAC(6)-Ib-cr); 3) production of efflux pumps, OqxAB and QepA; and 4) production of proteins protecting DNA gyrase, such as Qnr. The purpose of this review was to focus on the current status of cephalosporin and fluoroquinolone resistance, including mechanism of resistance as well as epidemiology of the antimicrobial resistance.

Full Text:



  • There are currently no refbacks.

Comments on this article

View all comments