Genetic heterogeneity and predominance of blaCTX-M-15 in cefotaxime-resistant Enterobacteriaceae isolates colonizing hospitalized children in Tunisia

Abstract

Extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae have emerged as important nosocomial pathogens. Community infections by these organisms have been also reported and were associated with previous intestinal colonization. We aimed to characterize cefotaxime‐resistant Enterobacteriaceae (CTX‐R‐En) isolated from hospitalized children in a Tunisian paediatric ward. Seventy CTX‐R‐En isolates were collected from 227 rectal swabs from hospitalized children in a paediatric ward. Antimicrobial susceptibility testing was determined according to the EUCAST guidelines. Isolates were characterized by polymerase chain reaction (PCR, genes encoding: ESBLs, pAmpC, carbapenemases, plasmid‐mediated quinolone resistance, virulence factors in Escherichia coli and Klebsiella pneumoniae isolates, occurrence of classes 1 and 2 integrons, phylogenetic groups of E. coli isolates, ERIC‐PCR and PCR‐based replicon typing) and conjugal transfer experiments. In total, 65 out of 227 (28·6%) hospitalized children were colonized with CTX‐M‐R‐En, and 70 isolates were identified. Isolates were 59 ESBL‐, 7 plasmidic‐AmpC (pAmpC)‐, 3 ESBL+pAmpC‐, and one ESBL+carbapenemase producers. The following bla genes were identified: blaCTX‐M‐15 (n = 54), blaCTX‐M‐1 (n = 5), blaCTX‐M‐9 (n = 2), blaCTX‐M‐13 (n = 1) and blaCTX‐M‐14 (n = 1), blaCMY‐2 (n = 5), blaCMY‐4 (n = 4), blaACC‐1 (n = 1) and blaOXA‐48 (n = 1). Our results showed that hospitalized children were colonized with various CTX‐R‐En‐producing several beta‐lactamase enzymes.

The Importance of Carbapenemase-Producing Enterobacterales in African Countries: Evolution and Current Burden

“…Similar strains were described by other authors in 2022 [151]. Another 2022 study, in which 227 hospitalized children were screened for MDR Enterobacteriaceae rectal colonization, reported only 1 patient (0.44%) with CPE carriage (a strain of bla OXA-48 Klebsiella oxytoca) [152]. In 2023, the first report of IMI-2-producing Enterobacter bugandensis isolated from the stool of a healthy volunteer in Tunisia was published [153].…”

Intestinal colonization with multidrug-resistant Enterobacterales: screening, epidemiology, clinical impact, and strategies to decolonize carriers

“…Gut colonization with MDR-Ent may also frequently involve pediatric patients. In Tanzania (2017-2018), Tunisia (2015), Gabon (2010-2011), and Cambodia (2012), 56%, 28.6%, 45%, and 55% of the hospitalized children were carriers of ESBL-Ent, respectively [64][65][66][67]. In Serbia (2017-2018), gut carriage with ESBL-producing Kp (ESBL-Kp) or ESBL-producing Ec (ESBL-Ec) was recorded in 59% of the hospitalized pre-term neonates; previous hospitalization, delivery by cesarean section, and mechanical ventilation were associated with colonization [68].…”

Efficacy of Amikacin and Cefotaxime Synergy Against CTX-M-15-Resistant Klebsiella pneumoniae in Neonatal Sepsis

“…This resistance has been linked to the presence of the blaCTX-M-15 gene, which encodes for an extended-spectrum betalactamase, on a plasmid found in all Klebsiella species (Ramdani Bouguessa et al, 2006;Chong et al, 2013;Hassan & Abdalhamid, 2014;Awosile et al, 2022). Recent studies have also highlighted the expanding range of detection for extendedspectrum beta-lactamases through real-time PCR (Yang et al, 2021;Harbaoui et al, 2022;Hasan & Swedberg, 2022).…”