shigellosis remains a common gastrointestinal disease mostly in children <5 years of age in developing countries. Azithromycin (AZM), a macrolide, is currently the first-line treatment for shigellosis in Bangladesh; ciprofloxacin (CIP) and ceftriaxone (CRO) are also used frequently. We aimed to evaluate the current epidemiology of antimicrobial resistance (AMR) and mechanism(s) of increasing macrolide resistance in in Bangladesh. A total of 2407 clinical isolates of from 2009 to 2016 were studied. Over the study period, was gradually increasing and become predominant (55%) over (36%) by 2016. We used CLSI-guided epidemiological cut-off value (ECV) for AZM in to set resistance breakpoints (zone-diameter ��� 15 mm for and ��� 11 mm for ). Between 2009 and 2016, AZM resistance increased from 22% to approximately 60%, CIP resistance increased by 40%, and CRO resistance increased from zero to 15%. The A gene was the key macrolide resistance factor in ; a 63MDa conjugative middle-range plasmid was harboring AZM and CRO resistance factors. Our findings show that, especially after 2014, there has been a rapid increase in resistance to the three most effective antibiotics. The rapid spread of macrolide (AZM) resistance genes among are driven by horizontal gene transfer rather than direct lineage.
References
Pediatr Clin North Am. 2017 Aug;64(4):799-814
[PMID: 28734511]
