Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among Klebsiella pneumoniae and Escherichia Coli

Abstract

Introduction:Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates.Objective:The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya.Methods:All clinical isolates (76 K. pneumoniae and 75 E. coli) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR).Results:Of the K. pneumoniae and E. coli tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the E. coli isolates were multidrug resistant compared with K. pneumoniae (65.8%). K. pneumoniae ESBL producers were significantly higher (85.5%) compared with (17.3%) E. coli isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of K. pneumoniae, and 4% E. coli isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, blaCMY (n=3), bla MOX (n=1), blaDHA (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: bla CMY and blaEBC (n=1), and blaCMY and blaMOX (n=2). Neither blaFOX nor blaACC was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units.Conclusion:Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.

Prevalence of plasmid-mediated AmpC beta-lactamases in Enterobacteria isolated from urban and rural folks in Uganda

“…Such extensive use of ceftriaxone could be a driving force behind the high pAmpC gene carriage rates. Coexistence between bla EBC and bla CIT genes in isolates has been reported before in Africa and Asia [35,38]. bla CIT reported in this study comprised of the bla CMY−2 and bla CMY−4 genes.…”

“…Furthermore, in this study, co-carriage rates of ESBL-and pAmpC genes was high, which is a cause for concern as individuals carrying strains producing these enzymes could be reservoirs of spread for MDR bacteria [33,34]. A signi cant number of isolates that were susceptible to third-generation cepharosporins but cefoxitin resistant carried pAmpC genes, a discordance that has been reported before [3,35]. The overall carriage rate (10%) for pAmpC genes in enterobacteriaceae in this study re ects extensive use of antibiotics, as found in Libya where a fecal carriage rate of 6.7% for pAmpC β-lactamase producing bacteria in the community was reported [36].…”

Emergence of AmpC β-Lactamase– and Metallo-β-Lactamase–producing Klebsiella pneumoniae in Sebha, Libya

“…A similar finding was reported by another study performed in Egypt [45]. Gentamicin resistance has also been reported as high in other Libyan hospitals [46]. The resistance of K. pneumoniae to gentamicin was 75%.…”

“…Such coproduction of ESBL and AmpC enzymes was also reported by Zorgani in 2017. All AmpC enzyme producers were isolated from patients admitted to teaching hospitals in Tripoli, Libya [46]. Further, AmpC enzyme-producing K. pneumoniae isolates were also recovered from the pediatric department in Tripoli, Libya [23].…”

Retrospective Analysis on Antimicrobial Resistance Trends and Prevalence of β-lactamases in Escherichia coli and ESKAPE Pathogens Isolated from Arabian Patients during 2000–2020

“…The results shown in Table 1 indicate that in Egypt from 2000 through 2020, resistance to various cephalosporins, such as cefuroxime, cefotaxime, ceftazidime, and cefepime, was higher than that to b-lactam/b-lactamase inhibitor combinations, e.g., amoxicillin-clavulanic acid and piperacillin-tazobactam. A rise in resistance was reported against aminoglycosides; gentamcin/amikacin, ciprofloxacin (a quinolone drug) and carbapenems, i.e., imipenem and meropenem [ 84 , 85 , 86 , 87 , 88 , 89 ]. The increase in antibiotic resistance in these isolates has also been demonstrated by β-lactamase detection.…”