scholarly journals Wastewater as a Probable Environmental Reservoir of Extended-Spectrum-β-Lactamase Genes: Detection of Chimeric β-Lactamases CTX-M-64 and CTX-M-123

2019 ◽  
Vol 85 (22) ◽  
Author(s):  
Hayato Tanaka ◽  
Wataru Hayashi ◽  
Masaki Iimura ◽  
Yui Taniguchi ◽  
Eiji Soga ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Content Type ◽  
E Coli ◽  
Chimeric Genes ◽  
Untreated Wastewater ◽  
Extended Spectrum ◽  
Antimicrobial Resistance Genes

ABSTRACT The presence of antimicrobial-resistant bacteria and resistance genes in aquatic environments is a serious public health concern. This study focused on Escherichia coli possessing blaCTX-M genes in wastewater inflows. Twelve crude inflow water samples from wastewater treatment plant (WWTP) A and two samples each from three other WWTPs were collected in 2017 and 2018. A total of 73 E. coli isolates with 31 different sequence types (STs) harboring distinctive blaCTX-M gene repertoires were detected. In WWTP A influents, blaCTX-M-14 (14 isolates) was dominant, followed by blaCTX-M-15 (12 isolates) and blaCTX-M-27 (10 isolates). The chimeric blaCTX-M-64 and blaCTX-M-123 genes were each identified in one of the E. coli isolates from the same WWTP A inflow port. The blaCTX-M-27 gene was associated with five of seven B2-ST131 isolates, including three isolates of the B2-O25b-ST131-H30R/non-Rx lineage. One of the remaining two isolates belonged to the B2-O25b-ST131-H30R/Rx lineage harboring the blaCTX-M-15 gene. As for the B2-O25b-ST131-H30R/non-Rx lineage, two isolates with blaCTX-M-27 were recovered from each of the WWTP B and D influents, and one isolate with blaCTX-M-174 was also recovered from WWTP B influent. Whole-genome sequencing of chimeric blaCTX-M-harboring E. coli isolates revealed that the blaCTX-M-64 gene was integrated into the chromosome of ST10 E. coli B22 via ISEcp1-mediated transposition of a 9,467-bp sequence. The blaCTX-M-123-carrying IncI1 plasmid pB64 was 109,169 bp in length with pST108. The overall findings suggest that wastewater may act as a probable reservoir of clinically significant clonal lineages mediating antimicrobial resistance genes and chimeric genes that have not yet been identified from human isolates of domestic origin in Japan. IMPORTANCE Global spread of CTX-M-type extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a critical concern in both clinical and community settings. This dominance of CTX-M-type ESBL producers may be largely due to the successful international spread of epidemic clones, as represented by the extraintestinal pathogenic Escherichia coli (ExPEC) ST131. Our findings highlight the worrisome presence of diverse E. coli clones associated with humans, including ExPEC lineages harboring the most common blaCTX-M variants in untreated wastewater samples. Moreover, the chimeric genes blaCTX-M-64 and blaCTX-M-123, which have not yet been identified from human isolates of domestic origin in Japan, were identified. Exposure to untreated wastewater through combined sewer overflow caused by heavy rains derived from abnormal weather change could pose a risk for human health due to ingesting those antimicrobial-resistant bacteria.

scholarly journals ESKAPE Bacteria and Extended-Spectrum-β-Lactamase-Producing Escherichia coli Isolated from Wastewater and Process Water from German Poultry Slaughterhouses

2020 ◽  
Vol 86 (8) ◽  
Author(s):  
Mykhailo Savin ◽  
Gabriele Bierbaum ◽  
Jens Andre Hammerl ◽  
Céline Heinemann ◽  
Marijo Parcina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wastewater Treatment ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Process Water ◽  
Resistant Bacteria ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Clinically Relevant Bacteria

ABSTRACT The wastewater of livestock slaughterhouses is considered a source of antimicrobial-resistant bacteria with clinical relevance and may thus be important for their dissemination into the environment. To get an overview of their occurrence and characteristics, we investigated process water (n = 50) from delivery and unclean areas as well as wastewater (n = 32) from the in-house wastewater treatment plants (WWTPs) of two German poultry slaughterhouses (slaughterhouses S1 and S2). The samples were screened for ESKAPE bacteria (Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) and Escherichia coli. Their antimicrobial resistance phenotypes and the presence of extended-spectrum-β-lactamase (ESBL), carbapenemase, and mobilizable colistin resistance genes were determined. Selected ESKAPE bacteria were epidemiologically classified using different molecular typing techniques. At least one of the target species was detected in 87.5% (n = 28/32) of the wastewater samples and 86.0% (n = 43/50) of the process water samples. The vast majority of the recovered isolates (94.9%, n = 448/472) was represented by E. coli (39.4%), the A. calcoaceticus-A. baumannii (ACB) complex (32.4%), S. aureus (12.3%), and K. pneumoniae (10.8%), which were widely distributed in the delivery and unclean areas of the individual slaughterhouses, including their wastewater effluents. Enterobacter spp., Enterococcus spp., and P. aeruginosa were less abundant and made up 5.1% of the isolates. Phenotypic and genotypic analyses revealed that the recovered isolates exhibited diverse resistance phenotypes and β-lactamase genes. In conclusion, wastewater effluents from the investigated poultry slaughterhouses exhibited clinically relevant bacteria (E. coli, methicillin-resistant S. aureus, K. pneumoniae, and species of the ACB and Enterobacter cloacae complexes) that contribute to the dissemination of clinically relevant resistances (i.e., blaCTX-M or blaSHV and mcr-1) in the environment. IMPORTANCE Bacteria from livestock may be opportunistic pathogens and carriers of clinically relevant resistance genes, as many antimicrobials are used in both veterinary and human medicine. They may be released into the environment from wastewater treatment plants (WWTPs), which are influenced by wastewater from slaughterhouses, thereby endangering public health. Moreover, process water that accumulates during the slaughtering of poultry is an important reservoir for livestock-associated multidrug-resistant bacteria and may serve as a vector of transmission to occupationally exposed slaughterhouse employees. Mitigation solutions aimed at the reduction of the bacterial discharge into the production water circuit as well as interventions against their further transmission and dissemination need to be elaborated. Furthermore, the efficacy of in-house WWTPs needs to be questioned. Reliable data on the occurrence and diversity of clinically relevant bacteria within the slaughtering production chain and in the WWTP effluents in Germany will help to assess their impact on public and environmental health.

scholarly journals Isolation and Characterization of NDM-Positive Escherichia coli from Municipal Wastewater in Jeddah, Saudi Arabia

2016 ◽  
Vol 60 (9) ◽  
pp. 5223-5231 ◽  
Author(s):  
David Mantilla-Calderon ◽  
Muhammad Raihan Jumat ◽  
Tiannyu Wang ◽  
Pugalenthi Ganesan ◽  
Nada Al-Jassim ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Saudi Arabia ◽  
Antibiotic Resistance ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Potential Hazard ◽  
Content Type ◽  
E Coli ◽  
Untreated Wastewater

ABSTRACTThe emergence of resistance to last-resort antibiotics is a public health concern of global scale. Besides direct person-to-person propagation, environmental pathways might contribute to the dissemination of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Here, we describe the incidence ofblaNDM-1, a gene conferring resistance to carbapenems, in the wastewater of the city of Jeddah, Saudi Arabia, over a 1-year period.blaNDM-1was detected at concentrations ranging from 104to 105copies/m3of untreated wastewater during the entire monitoring period. These results indicate the ubiquity and high incidence ofblaNDM-1in the local wastewater. To track the bacteria carryingblaNDM-1, we isolatedEscherichia coliPI7, a strain of sequence type 101 (ST101), from wastewater around the Hajj event in October 2013. Genome sequencing of this strain revealed an extensive repertoire of ARGs as well as virulence and invasive traits. These traits were further confirmed by antibiotic resistance profiling andin vitrocell internalization in HeLa cell cultures. Given that this strain remains viable even after a certain duration in the sewerage, and that Jeddah lacks a robust sanitary infrastructure to fully capture all generated sewage, the presence of this bacterium in the untreated wastewater represents a potential hazard to the local public health. To the best of our knowledge, this is the first report of ablaNDM-1-positiveE. colistrain isolated from a nonnosocomial environment in Saudi Arabia and may set a priority concern for the need to establish improved surveillance for carbapenem-resistantE. coliin the country and nearby regions.

scholarly journals Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

2014 ◽  
Vol 80 (12) ◽  
pp. 3656-3666 ◽  
Author(s):  
Basanta Kumar Biswal ◽  
Ramzi Khairallah ◽  
Kareem Bibi ◽  
Alberto Mazza ◽  
Ronald Gehr ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Peracetic Acid ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Antimicrobial Resistance Gene ◽  
Municipal Wastewaters ◽  
The Impact

ABSTRACTWastewater discharges may increase the populations of pathogens, includingEscherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenicEscherichia coli(UPEC), the most abundantE. colipathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766E. coliisolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.

Antimicrobial-Resistant and Extended-Spectrum β-Lactamase–Producing Escherichia coli in Raw Cow's Milk

2015 ◽  
Vol 78 (1) ◽  
pp. 72-77 ◽  
Author(s):  
ALENA SKOČKOVÁ ◽  
KATEŘINA BOGDANOVIČOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
RENÁTA KARPÍŠKOVÁ
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Diffusion Method ◽  
Cow’S Milk ◽  
Public Health Issue ◽  
Resistant Bacteria ◽  
Cow's Milk ◽  
E Coli ◽  
Extended Spectrum ◽  
Raw Cow’S Milk

The occurrence of antimicrobial-resistant bacteria is an important public health issue. The aim of this study was the monitoring of resistant Escherichia coli in raw cow's milk with a focus on the detection of extended-spectrum β-lactamase (ESBL)–producing strains. In total, 263 samples of raw milk from 40 farms were collected and investigated in 2010 to 2013 in the Czech Republic. Detection of E. coli was performed and evaluated according to ISO 16649-2, and antibiotic resistance was screened by the disk diffusion method. The presence of E. coli was detected in 243 (92.4%) samples. In total, 270 isolates were obtained. Resistance to β-lactam (31.8%) and tetracycline (13.0%) antibiotics was detected most often and also multiresistant strains (5.5%) were observed. E. coli isolates found to be resistant to β-lactam, tetracycline, and quinolone antibiotics were assayed by PCR to detect selected genes encoding those resistance mechanisms. In isolates in which any bla genes were detected, a double-disk synergy test was performed. ESBL production was confirmed in 2 (0.7%) isolates. The genetic analysis identified the presence of the blaCTX-M gene and other resistance genes (tet(B) and qnrB). Both ESBL-positive isolates originated from the same farm and had an identical pulsed-field gel electrophoresis profile. The findings of our study indicate that milk can be a reservoir of bacteria carrying resistance genes with a potential for spreading through the food chain.

scholarly journals Extended-spectrum beta-lactamase and ampicillin Class C beta lactamase-producing Escherichia coli from food animals: A review

2019 ◽  
pp. 65-75 ◽  
Author(s):  
Asinamai Athliamai Bitrus ◽  
Peter Anjili Mshelia ◽  
Iliya Dauda Kwoji ◽  
Mohammed Dauda Goni ◽  
Saleh Mohammed Jajere
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Beta Lactamase ◽  
Care Providers ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Extended Spectrum ◽  
Class C

Antimicrobial resistance has gained global notoriety due to its public health concern, the emergence of multiple drug-resistant bacteria, and lack of new antimicrobials. Extended-spectrum beta-lactamase (ESBL)/ampicillin Class C (AmpC)- producing Escherichia coli and other zoonotic pathogens can be transmitted to humans from animals either through the food chain, direct contact or contamination of shared environments. There is a surge in the rate of resistance to medically important antibiotics such as carbapenem, ESBL, aminoglycosides, and fluoroquinolones among bacteria of zoonotic importance. Factors that may facilitate the occurrence, persistence and dissemination of ESBL/AmpC-Producing E. coli in humans and animal includes; 1). o ral administration of antimicrobials to humans primarily (by physician and health care providers) and secondarily to animals, 2). importation of parent stock and day-old chickens, 3). farm management practice and lack of water acidification in poultry, 4). contamination of feed, water and environment, 5). contamination of plants with feces of animals. Understanding these key factors will help reduce the level of resistance, thereby boosting the therapeutic effectiveness of antimicrobial agents in the treatment of animal and human infections. This review highlights the occurrence, risk factors, and public health importance of ESBL/AmpC-beta-lactamase producing E. coli isolated from livestock.

scholarly journals Multiresistant Uropathogenic Escherichia coli from a Region in India Where Urinary Tract Infections Are Endemic: Genotypic and Phenotypic Characteristics of Sequence Type 131 Isolates of the CTX-M-15 Extended-Spectrum-β-Lactamase-Producing Lineage

2012 ◽  
Vol 56 (12) ◽  
pp. 6358-6365 ◽  
Author(s):  
Arif Hussain ◽  
Christa Ewers ◽  
Nishant Nandanwar ◽  
Sebastian Guenther ◽  
Savita Jadhav ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Sequence Type ◽  
Health Concern ◽  
Beta Lactam ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Tract Infections

ABSTRACTEscherichia colisequence type 131 (O25b:H4), associated with the CTX-M-15 extended-spectrum beta-lactamases (ESBLs) and linked predominantly to the community-onset antimicrobial-resistant infections, has globally emerged as a public health concern. However, scant attention is given to the understanding of the molecular epidemiology of these strains in high-burden countries such as India. Of the 100 clinicalE. coliisolates obtained by us from a setting where urinary tract infections are endemic, 16 ST131E. coliisolates were identified by multilocus sequence typing (MLST). Further, genotyping and phenotyping methods were employed to characterize their virulence and drug resistance patterns. All the 16 ST131 isolates harbored the CTX-M-15 gene, and half of them also carried TEM-1; 11 of these were positive forblaOXAgroups 1 and 12 foraac(6′)-Ib-cr. At least 12 isolates were refractory to four non-beta-lactam antibiotics: ciprofloxacin, gentamicin, sulfamethoxazole-trimethoprim, and tetracycline. Nine isolates carried the class 1 integron. Plasmid analysis indicated a large pool of up to six plasmids per strain with a mean of approximately three plasmids. Conjugation and PCR-based replicon typing (PBRT) revealed that the spread of resistance was associated with the FIA incompatibility group of plasmids. Pulsed-field gel electrophoresis (PFGE) and genotyping of the virulence genes showed a low level of diversity among these strains. The association of ESBL-encoding plasmid with virulence was demonstrated in transconjugants by serum assay. None of the 16 ST131 ESBL-producingE. colistrains were known to synthesize carbapenemase enzymes. In conclusion, our study reports a snapshot of the highly virulent/multiresistant clone ST131 of uropathogenicE. colifrom India. This study suggests that the ST131 genotypes from this region are clonally evolved and are strongly associated with the CTX-M-15 enzyme, carry a high antibiotic resistance background, and have emerged as an important cause of community-acquired urinary tract infections.

scholarly journals Molecular characterisation of extended-spectrum ß-lactamase producing Escherichia coli in wild birds and cattle, Ibadan, Nigeria

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Kayode Fashae ◽  
Ines Engelmann ◽  
Stefan Monecke ◽  
Sascha D. Braun ◽  
Ralf Ehricht
Keyword(s):  
Escherichia Coli ◽  
Wild Birds ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Molecular Characteristics ◽  
E Coli ◽  
Extended Spectrum ◽  
Faecal Samples ◽  
Geographical Regions ◽  
Ibadan Nigeria

Abstract Background Antimicrobial resistance (AMR) is an increasing global health concern reducing options for therapy of infections and also for perioperative prophylaxis. Many Enterobacteriaceae cannot be treated anymore with third generation cephalosporins (3GC) due to the production of certain 3GC hydrolysing enzymes (extended spectrum beta-lactamases, ESBLs). The role of animals as carriers and vectors of multi-resistant bacteria in different geographical regions is poorly understood. Therefore, we investigated the occurrence and molecular characteristics of ESBL-producing Escherichia coli (E. coli) in wild birds and slaughtered cattle in Ibadan, Nigeria. Cattle faecal samples (n = 250) and wild bird pooled faecal samples (cattle egrets, Bubulcus ibis, n = 28; white-faced whistling duck, Dendrocygna viduata, n = 24) were collected and cultured on cefotaxime-eosin methylene blue agar. Antimicrobial susceptibility was determined by agar diffusion assays and all 3GC resistant isolates were genotypically characterised for AMR genes, virulence associated genes (VAGs) and serotypes using DNA microarray-based assays. Results All 3GC resistant isolates were E. coli: cattle (n = 53), egrets (n = 87) and whistling duck (n = 4); cultured from 32/250 (12.8%), 26/28 (92.9%), 2/24(8.3%), cattle, egrets and whistling duck faecal samples, respectively. blaCTX-M gene family was prevalent; blaCTX-M15 (83.3%) predominated over blaCTX-M9 (11.8%). All were susceptible to carbapenems. The majority of isolates were resistant to at least one of the other tested antimicrobials; multidrug resistance was highest in the isolates recovered from egrets. The isolates harboured diverse repositories of other AMR genes (including strB and sul2), integrons (predominantly class 1) and VAGs. The isolates recovered from egrets harboured more AMR genes; eight were unique to these isolates including tetG, gepA, and floR. The prevalent VAGs included hemL and iss; while 14 (including sepA) were unique to certain animal isolates. E. coli serotypes O9:H9, O9:H30 and O9:H4 predominated. An identical phenotypic microarray profile was detected in three isolates from egrets and cattle, indicative of a clonal relationship amongst these isolates. Conclusion Wild birds and cattle harbour diverse ESBL-producing E. coli populations with potential of inter-species dissemination and virulence. Recommended guidelines to balance public health and habitat conservation should be implemented with continuous surveillance.

scholarly journals Abundance of colistin-resistant Escherichia coli harbouring mcr-1 and extended-spectrum β-lactamase-producing E. coli co-harbouring blaCTX-M-55 or -65 with blaTEM isolates from chicken meat in Vietnam

2021 ◽  
Author(s):  
Tatsuya Nakayama ◽  
Le Thi Hien ◽  
Ngo Thanh Phong ◽  
Doan Nguyen Minh Tran ◽  
Oanh Thi Hoang Nguyen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Contamination ◽  
Antibiotic Resistance Genes ◽  
Chicken Meat ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Extended Spectrum

Abstract Although the spread of plasmid-mediated antibiotic-resistant bacteria is a public health concern, food contamination with plasmid-mediated antibiotic-resistant Escherichia coli has not been well investigated in Vietnam. The aim of this study was to describe the prevalence of colistin-resistant, carbapenem-resistant and endemic blaCTX−M in extended-spectrum β-lactamase (ESBL)-producing E. coli isolates. Colistin- and carbapenem-resistant ESBL-producing E. coli were isolated from chickens in Vietnam and Japan. The results showed that 52% and 93% of Vietnamese chicken was isolated with colistin-resistant and AmpC/ESBL-producing E. coli, respectively, while 52.7% of Japanese chickens were isolated with AmpC/ESBL-producing E. coli. Carbapenem-resistant E. coli has not been isolated in Vietnam or Japan. Genotyping revealed that colistin-resistant E. coli harboured mcr-1, and most of the AmpC/ESBL-related genes were blaCTX−M−55 and blaCTX−M−65 together with blaTEM in Vietnamese chickens, and blaCMY−2 in Japanese chickens. Multidrug resistance analysis showed that ESBL-producing E. coli isolates were more resistant to quinolones, streptomycin, and chloramphenicol compared with colistin-resistant E. coli isolates from Vietnam, suggesting selection in ESBL-producing E. coli for multiple antibiotic resistance genes. In conclusion, colistin-resistant E. coli was detected in about half of the chicken meat samples, the majority of which were found to harbour mcr-1. The high prevalence of ESBL-producing E. coli has remained constant across the last five years, and the predominant blaCTX−M for ESBL-producing E. coli was found to be blaCTX−M−55 or blaCTX−M−65, with the coexistence of blaTEM in Vietnam. Our results can be implemented in monitoring systems to combat the development of antimicrobial resistance.

scholarly journals Genomic comparisons of Escherichia coli ST131 from Australia

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Dmitriy Li ◽  
Ethan R. Wyrsch ◽  
Paarthiphan Elankumaran ◽  
Monika Dolejska ◽  
Marc S. Marenda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Type Species ◽  
Companion Animals ◽  
Snp Analysis ◽  
Complete Class ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Antimicrobial Resistance Genes

Escherichia coli ST131 is a globally dispersed extraintestinal pathogenic E. coli lineage contributing significantly to hospital and community acquired urinary tract and bloodstream infections. Here we describe a detailed phylogenetic analysis of the whole genome sequences of 284 Australian ST131 E. coli isolates from diverse sources, including clinical, food and companion animals, wildlife and the environment. Our phylogeny and the results of single nucleotide polymorphism (SNP) analysis show the typical ST131 clade distribution with clades A, B and C clearly displayed, but no niche associations were observed. Indeed, interspecies relatedness was a feature of this study. Thirty-five isolates (29 of human and six of wild bird origin) from clade A (32 fimH41, 2 fimH89, 1 fimH141) were observed to differ by an average of 76 SNPs. Forty-five isolates from clade C1 from four sources formed a cluster with an average of 46 SNPs. Within this cluster, human sourced isolates differed by approximately 37 SNPs from isolates sourced from canines, approximately 50 SNPs from isolates from wild birds, and approximately 52 SNPs from isolates from wastewater. Many ST131 carried resistance genes to multiple antibiotic classes and while 41 (14 %) contained the complete class one integron–integrase intI1, 128 (45 %) isolates harboured a truncated intI1 (462–1014 bp), highlighting the ongoing evolution of this element. The module intI1–dfrA17–aadA5–qacEΔ1–sul1–ORF–chrA–padR–IS1600–mphR–mrx–mphA, conferring resistance to trimethoprim, aminoglycosides, quaternary ammonium compounds, sulphonamides, chromate and macrolides, was the most common structure. Most (73 %) Australian ST131 isolates carry at least one extended spectrum β-lactamase gene, typically bla CTX-M-15 and bla CTX-M-27. Notably, dual parC-1aAB and gyrA-1AB fluoroquinolone resistant mutations, a unique feature of clade C ST131 isolates, were identified in some clade A isolates. The results of this study indicate that the the ST131 population in Australia carries diverse antimicrobial resistance genes and plasmid replicons and indicate cross-species movement of ST131 strains across diverse reservoirs.

Occurrence of extended-spectrum β-lactamase, AmpC and virulence genes in Escherichia coli isolates from vegetable salads in Morocco

2017 ◽  
Vol 119 (7) ◽  
pp. 1633-1647
Author(s):  
Kaotar Nayme ◽  
Abouddihaj Barguigua ◽  
Brahim Bouchrif ◽  
Idrissa Diawara ◽  
Fatima El Otmani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Phylogenetic Group ◽  
Pulsed Field Gel Electrophoresis ◽  
Resistant Bacteria ◽  
Content Type ◽  
Pulsed Field ◽  
E Coli ◽  
Extended Spectrum

Purpose The purpose of this paper is to assess the occurrence of the extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamase genes in 144 Escherichia coli isolates recovered from 160 vegetable salad samples. Design/methodology/approach Among the 144 E. coli isolates recovered from 160 vegetable salads, 17 (12 percent) ceftazidime-resistant isolates were screened for ESBL production with the double disk-diffusion test. The ESBL-producing isolates were characterized for antimicrobial resistance, the presence of virulence genes and plasmid-mediated quinolone resistance (PMQR) determinants. The isolates were also subjected to phylogenetic group typing. The existence of plasmid AmpC genes and mutations in the regulatory region of the chromosomal AmpC gene was assessed using polymerase chain reaction (PCR) and sequencing. All β-lactamase isolates were further characterized by pulsed-field gel electrophoresis to determine the genetic relatedness. Findings Overall, 17 (12 percent) of the 144 E. coli isolates studied were ceftazidime resistant. Among the 17 isolates, 13 (77 percent) were multidrug resistant and four (23.5 percent) were ESBL producers. The bla CTX-M14 was the only gene detected. Of the 12 AmpC-producing isolates, three (18 percent) harbored plasmid-encoded AmpC and sequencing analysis of the chromosomal AmpC genes revealed mutations in the promoter/attenuator region. PMQR determinants were detected in 9 (52 percent) isolates. A was the most prevalent phylogenetic group (56 percent), followed by groups B1 (31 percent), D (6 percent), and B2 (6 percent). PCR showed that six (50 percent) ESBL/AmpC-producing E. coli isolates carried one and/or two virulence genes. Pulsed-field gel electrophoresis showed no epidemiological relationship between these isolates. Originality/value This study places vegetable salads within the spectrum of ecological niches that may be vehicles for antibiotic-resistant bacteria/genes with clinical interest and these findings are worthy of attention as their spread to humans by ingestion cannot be dismissed.

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