Objectives Fast and adequate detection of extended-spectrum b-lactamases (ESBLs) is crucial for infection control measures and the choice of antimicrobial therapy. The aim of this study was to ...develop and evaluate a novel ESBL assay using ligation-mediated amplification combined with microarray analysis to detect the most prevalent ESBLs in Enterobacteriaceae: TEM, SHV and CTX-M. Methods Analysis of the Lahey database revealed that the vast majority of TEM and SHV ESBLs differ from non-ESBL variants in three amino acid positions. TEM ESBLs have at least one of the following amino acid substitutions: R164S/H/C, G238D/N/S and E104K. In SHV ESBLs, one or more of the following substitutions is observed: D179A/N/G, G238S/A and E240K. Oligonucleotide probes were designed to detect these substitutions, covering 95% of ESBL TEM variants and 77% of ESBL SHV variants. In addition, probes were designed to distinguish between CTX-M groups 1, 2, 9 and 8/25. For evaluation of the assay, 212 Enterobacteriaceae isolates with various b-lactamases were included (n=106 ESBL positive). Results The sensitivity of the microarray was 101/106 (95%; 95% CI 89%-98%), and the specificity 100% (95% CI 97%-100%) using molecular characterization of ESBLs by PCR and sequencing as reference. Assay performance time was 8 h for 36 isolates. Conclusions This novel commercially available DNA microarray system may offer an attractive option for rapid and accurate detection of CTX-M, TEM and SHV ESBL genes in Enterobacteriaceae in the clinical laboratory.
Foodstuffs are a well-documented source of multidrug-resistant bacteria, and hospitalized patients are usually susceptible to hospital infections owing to their immune status. Therefore, this study ...aimed to investigate the presence of beta-lactamase-producing Enterobacterales in ready-to-eat foods consumed by hospitalized patients. For this purpose, 51 vegetable and meat samples were collected over 2 months and analyzed. Enterobacterales isolates were identified and subjected to antimicrobial susceptibility testing, followed by beta-lactamase gene screening, pH tolerance assays, and whole-genome sequencing (WGS). Isolates harboring genes encoding extended-spectrum beta-lactamases, cephalosporinases, or carbapenemases were detected, and all isolates tolerated pH levels similar to those in the human gastrointestinal tract. The blaKPC-2 carriers were characterized by WGS and lineages closely related to those causing human infections were identified. These results showed that dietary intake is an alternative route for the transmission of antimicrobial-resistant bacteria, which must be considered when designing effective strategies for infection control.
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•Multidrug-resistant Enterobacterales were isolated from food served to patients.•Isolates tolerate the pH conditions of the human gastrointestinal tract.•A Klebsiella michiganensis isolate ST451 presented blaKPC-2 in an IncN2 plasmid.•KPC-2-producing Enterobacter hormaechei isolates ST114 and ST269 were also detected.•Carbapenemase producing isolates were identified as potential pathogens.
Abstract Objective The objective of this study was to determine the proportion of extended spectrum β-lactamase producing gram-negative bacteria (ESBL-GNB) colonizing patients admitted at Mazimbu ...hospital and Morogoro Regional hospital, in Morogoro, Tanzania. Rectal colonization with ESBL-GNB increases the risks of developing bacterial infections by extra-intestinal pathogenic ESBL-GNB. Results Of the 285 patients investigated, 123 (43.2%) carried ESBL-GNB in their intestines. Five of the 123 ESBL positive patients were colonized with two different bacteria, making a total of 128 ESBL producing isolates. Escherichia coli (n = 95, 74.2%) formed the majority of ESBL isolates. The proportion of CTX-M-1 group genes among ESBL isolates tested was 94.9% (93/98). History of antibiotic use (OR: 1.83, 95% CI: 1.1–3.2, P = 0.03), being on antibiotic treatment (OR: 2.61, 95% CI: 1.5–4.53, P = 0.001), duration of hospital stay (OR: 1.2, 95% CI: 1.1–1.3, P < 0.001) and history of previous admission (OR: 2.24, 95% CI: 1.2–4.1, P = 0.009) independently predicted ESBL-GNB carriage.
A prospective cohort study was performed among travelers from the Netherlands to investigate the acquisition of carbapenemase-producing
Enterobacteriaceae
(CP-E) and extended-spectrum ...β-lactamase–producing
Enterobacteriaceae
(ESBL-E) and associated risk factors. Questionnaires were administered and rectal swab samples were collected and tested before and after traveler return. Of 370 travelers, 32 (8.6%) were colonized with ESBL-E before trave,; 113 (30.5%) acquired an ESBL-E during travel, and 26 were still colonized 6 months after return. No CP-E were found. Independent risk factors for ESBL-E acquisition were travel to South and East Asia. Multilocus sequence typing showed extensive genetic diversity among
Escherichia coli
. Predominant ESBLs were CTX-M enzymes. The acquisition rate, 30.5%, of ESBL-E in travelers from the Netherlands to all destinations studied was high. Active surveillance for ESBL-E and CP-E and contact isolation precautions may be recommended at admission to medical facilities for patients who traveled to Asia during the previous 6 months.
The increasing incidence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and Gram negative organisms that has been observed in food animals such as ...poultry, cattle and pigs, are suggestive that animals, food and environment are potential sources of ESBL-producing bacteria. Hence, the aim of this study was to characterized commensal E. coli obtained from healthy broiler and turkey flocks at slaughter for the presence of penicillinases-, ESBL-, extended-spectrum AmpC (ESAC)-, plasmid-mediated quinolone resistance- and MCR-encoding genes. Study of clonal relatedness showed genetic diversity among CTX-M-type, SHV-12 and TEM-52 producing isolates with human isolates of the same type, was also assessed. We detected that eleven (5.4%, 11/202) and forty-five (2.2%, 45/185) E. coli isolates from broilers and turkeys, respectively, carried blaESBL or blaESAC genes and two isolates from turkeys carried mcr-1 gene. A new variant blaCTX-M-166 was reported in a multidrug resistant isolate from a broiler flock. Overall, we detected a diversity of resistance mechanisms among E. coli from food-producing animals, all of them with high importance at a public health level.
•Detection of blaESBL, blaESAC and the recently described mcr-1 gene.•New variant blaCTX-M-166 reported in a MDR isolate from a broiler flock.•WGS approach revealed a CTX-M-166-harboring O6:H16 ST48-fimH34 E. coli.•ESBL-producing E. coli in the poultry population was not due to one specific clone.
Municipal wastewater treatment plants (MWWTPs) are a global source of antibiotic resistance genes (ARGs), collecting wastewater from a variety of sources, including hospital wastewater, domestic ...wastewater, runoff from agricultural and livestock farms, etc. These sources are contaminated with organic and inorganic pollutants, ARGs and antibiotic-resistant bacteria (ARB). Such pollutants aided eutrophication and encouraged bacterial growth. During bacterial growth horizontal gene transfer (HGT) and vertical gene transfer (VGT) of ARGs and extended-spectrum β-lactamase (ESBL) encoding genes may facilitate, resulting in the spread of antibiotic resistance exponentially. The current study investigated the prevalence of multidrug resistance (MDR) and ESBL encoding genes in various treatment units of MWWTP and their spread in the environment. A total of three sampling sites (BUT, BRO, and BFB) were chosen, and 33 morphologically distinct bacterial colonies were isolated. 14 of the 33 isolates tested positive for antibiotic resistance and were further tested for the coexistence of MDR and ESBL production. The selected 14 isolates showed the highest resistance to trimethoprim (85.71%), followed by ciprofloxacin, azithromycin, and ampicillin (71.42%), tetracycline (57.14%), and vancomycin, gentamicin, and colistin sulphate (50%). A total of 9 isolates (64.28%) were phenotypically positive for ESBL production (BUT2, BUT3, BUT5, BRO1, BRO2, BRO3, BRO4, BRO5 and BFB1). The molecular detection of ESBL encoding genes, i.e. blaTEM, blaSHV, and blaCTX-M was carried out. The most prevalent gene was blaTEM (69.23%), followed by blaSHV (46.15%), and blaCTX-M (23.07%). In this study, 9 isolates (64.28%) out of 14 showed the coexistence of MDR and ESBL encoding genes, namely BUT3, BUT4, BUT5, BUT6, BUT7, BRO1, BRO2, BRO4, and BFB1. The coexistence of ESBL encoding genes and resistance to other antibiotic classes exacerbates human health and the environment.
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•Antibiotic pollution in the environment.•Spreading of antibiotic resistance gene from municipal wastewater treatment plant.•Co-occurrence of antibiotic resistance and extended spectrum beta lactamase (ESBL).•Molecular detection of beta lactamase (β-lactamase) genes in municipal wastewater.•BlaTEM, blaSHV, and blaCTX-M dissemination in municipal wastewater treatment plant.
Enterobacter cloacae complex (ECC) members are rapidly emerging as successful nosocomial pathogens, especially, with the emergence of carbapenem-resistant clones. In this study, we performed a ...comprehensive molecular characterization of a carbapenem-resistant E. hormaechei ssp. xiangfangensis LAU_ENC1. hsp60 and average nucleotide identity (ANI) were used for its identification. The repertoire of resistance genes and phage content were analyzed. Plasmid sequences were extracted and compared to closest references. The isolate LAU_ENC1 was identified as an E. hormaechei ssp. xiangfangensis and belonged to ST-114A sub-cluster. blaNDM-1, blaCTX-M-15, blaOXA-1, and blaACT-16 genes were detected as β-lactam resistance determinants. A chromosomal hybrid intact phage, Enterobacter phage LAU1, with blaCTX-M-15 integrated in its direct vicinity within an ISEcp1 - blaCTX-M-15 - wbuC - ∆Tn2 rare cassette was detected. blaNDM-1 was integrated within a novel IncFII conjugative plasmid, pLAU_ENC1, through an IS3000- ΔISAba125-blaNDM-1-bleMBL−//−Tn5403 cassette. To our knowledge, this is the first report of a multi-drug resistant (MDR) E. hormaechei ssp. xiangfangensis carrying a blaCTX-M-15 integrated within the proximity of a provirus chromosomal region. Treatment options for MDR ECC members are becoming scarce, thus warranting an increased monitoring of the dissemination of these pathogens in clinical settings.
•Genome characterization of MDR Enterobacter hormaechei ssp. Xiangfangensis (LAU_ENC1)•LAU_ENC1 belongs to ST-1144 sub-cluster co-harbouring blaNDM-1 and a Chromosomally encoded phage-linked blaCTX-M-15 genes.•blaCTX-M-15 was integrated within an ISEcp1- blaCTX-M-15-wbuC- ∆Tn2 rare cassette.•blaCTX-M-15 was integrated in the vicinity of Enterobacter intact phage LAU1.•blaNDM-1 was integrated within a novel IncFII conjugative plasmid.
Resistance to antimicrobial agents has become a major source of morbidity and mortality worldwide. When antibiotics were first introduced in the 1900's, it was thought that we had won the war against ...microorganisms. It was soon discovered however, that the microorganisms were capable of developing resistance to any of the drugs that were used. Apparently most pathogenic microorganisms have the capability of developing resistance to at least some antimicrobial agents. The main mechanisms of resistance are: limiting uptake of a drug, modification of a drug target, inactivation of a drug, and active efflux of a drug. These mechanisms may be native to the microorganisms, or acquired from other microorganisms. Understanding more about these mechanisms should hopefully lead to better treatment options for infective diseases, and development of antimicrobial drugs that can withstand the microorganisms attempts to become resistant.
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