Diversity of extended-spectrum and plasmid-mediated AmpC β-lactamases in Enterobacteriaceae isolates from portuguese health care facilities

Abstract

A group of 124 Enterobacteriaceae isolates resistant to third generation cephalosporins, and collected in distinct health care facilities of different Portuguese regions was analysed. The great majority of the isolates were also resistant to fourth generation cephalosporins (83.9%), monobactam (96%), amoxicillin plus clavulanic acid (85.5%), and piperacillin plus tazobactam (66.9%). Overall, 84.7% (105/124) were multidrug resistant. Molecular methods enabled us to identify 86.3% (107/124) extended-spectrum β-lactamases (ESBL) producers, revealing a diversity of class A β-lactamases from different families, like TEM (TEM-1, TEM-10, TEM-24, and TEM-52), SHV (SHV-1, SHV-12, and SHV-28), CTX-M (CTX-M-1, CTX-M-9, CTX-M-14, CTX-M-15, and CTXM-32), and GES (GES-1). We have also detected class C enzymes like plasmid-mediated AmpC β-lactamases (PMAβs, DHA-1, and CMY-2) and chromosomal AmpCs in Enterobacter and Citrobacter spp. The PMAβ genetic context mapping suggests association with mobile elements, plasmid importation and the potential emergence of these β-lactamases. The most prevalent β-lactamase detected was CTX-M-15 (66.1%) and in 41.1% of the isolates it was associated with TEM-, OXA-type β-lactamases and Aac(6)᾿Ib-cr, which might indicate that the respective genotype has settled in our country. Indeed, CTX-M-15 was distributed amongst distinct clinical settings of several health care facilities (93.5%) from various regions. We provide evidence of a concerning clinical situation that includes vast occurrence of ESBLs, the settling of CTX-M β-lactamases, and the report of plasmidic and chromosomal AmpC in Portugal.

Prevalence and molecular typing of extended-spectrum -lactamases in Escherichia coli, Enterobacter cloacae and Citrobacter freundii isolates from Laghouat Hospital, Algeria

“…Moreover, it is worth noting that, the principal source of isolation the ESBL-producing isolates in our study was urine with the proportion 52.38%; our results are in accordance with other recent studies realized on a group of 124 Enterobacteriaceae isolates resistant to third generation cephalosporin, and collected in distinct health care facilities of different Portuguese regions, which have even described a 58.9% clinical strains were isolated from urine (Jones-Dias et al, 2014). However, studies have shown that ESBL producing uropathogens have their reservoir in the digestive tract (Anil Kumar and Babu, 2013).…”

High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Enterobacteriaceae Isolated from Gull Feces in Lisbon, Portugal

“…The principal ESBL identified in this study was CTX-M-15, which corresponds to the predominant ESBL found among clinical Enterobacteriaceae in Portugal [ 24 , 39 , 40 ] and worldwide [ 41 ]. This ESBL was actually massively detected among healthy pigs in Portugal [ 42 ], either in E. coli or K. pneumoniae .…”

Architecture of Class 1, 2, and 3 Integrons from Gram Negative Bacteria Recovered among Fruits and Vegetables

“…Double disk synergy test was used to phenotypically detect the presence of specific groups of β-lactamases in the 333 isolates: amoxicillin (25 μg) and amoxicillin plus clavulanic acid (20 + 10 μg) for the phenotypic detection of penicillinases, cefotaxime (5 μg) and amoxicillin clavulanic acid (20 + 10 μg) for ESBL, cefoxitin (30 μg) and cloxacillin (750 μg) for AmpC β-lactamases, and imipenem (5 μg) and imipenem plus dipicolinic acid (750 μg) for metallo-β-lactamases. Escherichia coli ATCC® 25922™ was also tested as a control of this technique (Jones-Dias et al, 2014 ).…”