ShigellaAntimicrobial Drug Resistance Mechanisms, 2004–2014

Abstract

To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004–2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis.

Increasing Antibiotic Resistance inShigellaspp. from Infected New York City Residents, New York, USA

“…When antibiotics are prescribed, therapy should be modified on the basis of sensitivity testing; however, without CLSI-defined clinical breakpoints for azithromycin, this process will be challenging ( 4 , 14 , 15 ). …”

Molecular characterization of antimicrobial resistance in clinical Shigella isolates during 2014 and 2015: trends in South India

“…The presence of PMQR genes is a great concern because they can promote mutations within the quinolone resistance determining region (QRDR), which results in fluoroquinolone resistance, but may also disseminate to other species of Enterobacteriaceae. 3 In this study, qnr genes were frequently seen in S. flexneri isolates than in S. sonnei, which could be due to the fact that qnrS gene was first detected in a S. flexneri serotype 1a in 2002, and later reported from Japan in 2005. 24 At the same time, qnrS was the commonly found allele of the qnr genes, followed by qnrB in Shigella spp.…”

“…In contrast S. flexneri is predominant in developing countries, while S. dysenteriae and S. boydii are rarely isolated. 3 Although shigellosis is primarily self-limiting, antibiotics are recommended for reducing illness duration and for preventing transmission; the current drugs of choice are fluoroquinolones and third generation cephalosporins. 4 However, antimicrobial resistance (AMR) is an emerging problem among Shigella spp., particularly in Asia and Africa.…”

Ciprofloxacin facilitates the transfer of XDR plasmids from commensalE. coliinto epidemic fluoroquinolone-resistantShigella sonnei

“…Subsequently, minimal inhibitory concentrations (MICs) against ciprofloxacin, azithromycin, gentamicin, and ceftriaxone were measured using the E-test (AB Biodisk), according to the manufacturer’s instructions. All antimicrobial testing was performed on Mueller-Hinton agar and susceptibility criteria were interpreted following the CLSI 2016 guidelines 15 . MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories; XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e.…”

“…These organisms carried the classical chromosomal point mutations in the quinolone resistance determining regions (QRDRs) at codon 83 (serine to leucine) and codon 87 (aspartic acid to glycine/asparagine) in gyrA , and at codon 80 (serine to isoleucine) in parC 11,12 . From 2010 onwards, cipR S. sonnei emerged as a major global health concern, becoming widely distributed through international travel and ensuing domestic transmission 13–15 . To date, cipR S. sonnei has been reported in children across Asia 16,17 , as well as homeless individuals and men-who-have-sex-with-men (MSM) in Canada, the US, Taiwan, and the UK 14,18–20 .…”