scholarly journals Dominance of ST131Escherichia colicarryingblaCTX-Min patients with bloodstream infections caused by cephalosporin-resistant strains in Australia, New Zealand and Singapore: whole genome analysis of isolates from a randomised trial

2017 ◽  
Author(s):  
Patrick N. A. Harris ◽  
Nouri L. Ben Zakour ◽  
Leah W. Roberts ◽  
Alexander M. Wailan ◽  
Hosam M. Zowawi ◽  
...  

Synopsis/AbstractObjectivesTo characterise multi-drug resistantEscherichia coliisolated from patients in Australia, New Zealand and Singapore with bloodstream infection (BSI).MethodsWe prospectively collected third-generation cephalosporin resistant (3GC-R)E. colifrom blood cultures obtained from patients enrolled in a randomised controlled trial. Whole genome sequencing was used to characterise antibiotic resistance genes, sequence types (STs), plasmids and phylogenetic relationships. Antibiotic susceptibility was determined using disk diffusion and Etest.ResultsA total of 70E. coliwere included, of which the majority were ST131 (61.4%). BSI was most frequently from a urinary source (69.6%), community-associated (62.9%) and in older patients (median age 71 years [IQR 64-81]). The median Pitt bacteraemia score at presentation was 1 (IQR 0-2, range 0-3) and ICU admission was infrequent (3.1%). ST131 possessed significantly more acquired resistance genes than non-ST131 (p=0.003). Clade C1/C2 ST131 predominated (30.2% and 53.5% of all ST131 respectively) and these were all resistant to ciprofloxacin. All clade A ST131 were community-associated. The predominant ESBL types wereblaCTX-M(78.6% of isolates) and were strongly associated with ST131, with the majorityblaCTX-M-15. Clade C1 was associated withblaCTX-M-14andblaCTX-M-27, whereasblaCTX-M-15predominated in clade C2. Plasmid-mediated AmpC (p-AmpC) genes (mainlyblaCMY-2) were also frequent (17.1%) but were more common with non-ST131 strains (p< 0.001). The majority of plasmid replicon types were IncF.ConclusionsIn a prospective collection of 3GC-RE. colicausing BSI in the Australasian region, community-associated Clade C1/C2 ST131 predominate in association withblaCTX-MESBLs, although a significant proportion of non-ST131 strains carriedblaCMY-2.

2021 ◽  
Vol 12 ◽  
Author(s):  
Loandi Richter ◽  
Erika M. du Plessis ◽  
Stacey Duvenage ◽  
Mushal Allam ◽  
Arshad Ismail ◽  
...  

The increasing occurrence of multidrug-resistant (MDR) extended-spectrum β-lactamase- (ESBL) and/or AmpC β-lactamase- (AmpC) producing Enterobacterales in irrigation water and associated irrigated fresh produce represents risks related to the environment, food safety, and public health. In South Africa, information about the presence of ESBL/AmpC-producing Enterobacterales from non-clinical sources is limited, particularly in the water–plant-food interface. This study aimed to characterize 19 selected MDR ESBL/AmpC-producing Escherichia coli (n=3), Klebsiella pneumoniae (n=5), Serratia fonticola (n=10), and Salmonella enterica (n=1) isolates from spinach and associated irrigation water samples from two commercial spinach production systems within South Africa, using whole genome sequencing (WGS). Antibiotic resistance genes potentially encoding resistance to eight different classes were present, with blaCTX-M-15 being the dominant ESBL encoding gene and blaACT-types being the dominant AmpC encoding gene detected. A greater number of resistance genes across more antibiotic classes were seen in all the K. pneumoniae strains, compared to the other genera tested. From one farm, blaCTX-M-15-positive K. pneumoniae strains of the same sequence type 985 (ST 985) were present in spinach at harvest and retail samples after processing, suggesting successful persistence of these MDR strains. In addition, ESBL-producing K. pneumoniae ST15, an emerging high-risk clone causing nosocomical outbreaks worldwide, was isolated from irrigation water. Known resistance plasmid replicon types of Enterobacterales including IncFIB, IncFIA, IncFII, IncB/O, and IncHI1B were observed in all strains following analysis with PlasmidFinder. However, blaCTX-M-15 was the only β-lactamase resistance gene associated with plasmids (IncFII and IncFIB) in K. pneumoniae (n=4) strains. In one E. coli and five K. pneumoniae strains, integron In191 was observed. Relevant similarities to human pathogens were predicted with PathogenFinder for all 19 strains, with a confidence of 0.635–0.721 in S. fonticola, 0.852–0.931 in E. coli, 0.796–0.899 in K. pneumoniae, and 0.939 in the S. enterica strain. The presence of MDR ESBL/AmpC-producing E. coli, K. pneumoniae, S. fonticola, and S. enterica with similarities to human pathogens in the agricultural production systems reflects environmental and food contamination mediated by anthropogenic activities, contributing to the spread of antibiotic resistance genes.


2019 ◽  
Vol 74 (8) ◽  
pp. 2176-2180
Author(s):  
Daira Melendez ◽  
Marilyn C Roberts ◽  
Alexander L Greninger ◽  
Scott Weissman ◽  
David No ◽  
...  

Abstract Background Limited studies have investigated the microbial diversity of wild marine mammals. Objectives This study characterized Escherichia coli isolates collected from fresh faecal samples of endangered southern resident killer whales (Orcinus orca) located by detection dogs. Methods WGS of each strain was done to determine ST (using MLST), clonotype (C:H), antimicrobial resistance and virulence profile. Conjugation experiments were done to determine the mobility of the tet(B) tetracycline resistance gene. Results All isolates belonged to extraintestinal pathogenic E. coli (ExPEC) clonal lineages ST73 (8/9) and ST127 (1/9), often associated with human community-acquired urinary tract disease. Clonotyping using fumC and fimH alleles showed divergence in clonal lineages, with ST73 isolates belonging to the C24:H10 clade and the ST127 isolate belonging to C14:H2. The eight ST73 isolates carried multiple acquired antibiotic resistance genes, including aadA1, sul1 and tet(B), encoding aminoglycoside, sulphonamide and tetracycline resistance, respectively. Conjugative transfer of the resistance gene tet(B) was observed for three of the eight isolates. ST127 did not carry any of these acquired resistance genes. Virulence-associated genes identified included those encoding adhesins (iha, papC, sfaS), toxins (sat, vat, pic, hlyA, cnf1), siderophores (iutA, fyuA, iroN, ireA), serum survival/protectins (iss, ompT), capsule (kpsM) and pathogenicity island marker (malX). Conclusions Orca whales can carry antibiotic-resistant potentially pathogenic strains of E. coli. Possible sources include contamination of the whale’s environment and/or food. It is unknown whether these isolates cause disease in southern resident killer whales, which could contribute to the ongoing decline of this critically endangered population.


2021 ◽  
Vol 9 (2) ◽  
pp. 308
Author(s):  
Michaela Kubelová ◽  
Ivana Koláčková ◽  
Tereza Gelbíčová ◽  
Martina Florianová ◽  
Alžběta Kalová ◽  
...  

The great plasticity and diversity of the Escherichia coli genome, together with the ubiquitous occurrence, make E. coli a bacterium of world-wide concern. Of particular interest are pathogenic strains and strains harboring antimicrobial resistance genes. Overlapping virulence-associated traits between avian-source E. coli and human extraintestinal pathogenic E. coli (ExPEC) suggest zoonotic potential and safety threat of poultry food products. We analyzed whole-genome sequencing (WGS) data of 46 mcr-1-positive E. coli strains isolated from retail raw meat purchased in the Czech Republic. The investigated strains were characterized by their phylogroup—B1 (43%), A (30%), D (11%), E (7%), F (4%), B2 (2%), C (2%), MLST type, and serotype. A total of 30 multilocus sequence types (STs), of which ST744 was the most common (11%), were identified, with O8 and O89 as the most prevalent serogroups. Using the VirulenceFinder tool, 3 to 26 virulence genes were detected in the examined strains and a total of 7 (15%) strains met the pathogenic criteria for ExPEC. Four strains were defined as UPEC (9%) and 18 (39%) E. coli strains could be classified as APEC. The WGS methods and available on-line tools for their evaluation enable a comprehensive approach to the diagnosis of virulent properties of E. coli strains and represent a suitable and comfortable platform for their detection. Our results show that poultry meat may serve as an important reservoir of strains carrying both virulence and antibiotic resistance genes for animal and human populations.


2004 ◽  
Vol 48 (10) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yolanda Sáenz ◽  
Laura Briñas ◽  
Elena Domínguez ◽  
Joaquim Ruiz ◽  
Myriam Zarazaga ◽  
...  

ABSTRACT Seventeen multiple-antibiotic-resistant nonpathogenic Escherichia coli strains of human, animal, and food origins showed a wide variety of antibiotic resistance genes, many of them carried by class 1 and class 2 integrons. Amino acid changes in MarR and mutations in marO were identified for 15 and 14 E. coli strains, respectively.


2019 ◽  
Vol 12 (7) ◽  
pp. 984-993 ◽  
Author(s):  
Md. Abdus Sobur ◽  
Abdullah Al Momen Sabuj ◽  
Ripon Sarker ◽  
A. M. M. Taufiqur Rahman ◽  
S. M. Lutful Kabir ◽  
...  

Aim: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. Materials and Methods: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR. The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. Results: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). Conclusion: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mo Jia ◽  
Ifigenia Geornaras ◽  
Jennifer N. Martin ◽  
Keith E. Belk ◽  
Hua Yang

A comparative whole genome analysis was performed on three newly sequenced Escherichia coli O157:H7 strains with different stx profiles, previously isolated from feedlot cattle [C1-010 (stx1−, stx2c+), C1-057 (stx−), and C1-067 (stx1+, stx2a+)], as well as five foodborne outbreak strains and six stx-negative strains from NCBI. Phylogenomic analysis demonstrated that the stx2c-carrying C1-010 and stx-negative C1-057 strains were grouped with the six NCBI stx-negative E. coli O157:H7 strains in Cluster 1, whereas the stx2a-carrying C1-067 and five foodborne outbreak strains were clustered together in Cluster 2. Based on different clusters, we selected the three newly sequenced strains, one stx2a-carrying strain, and the six NCBI stx-negative strains and identify their prophages at the stx insertion sites. All stx-carrying prophages contained both the three Red recombination genes (exo, bet, gam) and their repressor cI. On the other hand, the majority of the stx-negative prophages carried only the three Red recombination genes, but their repressor cI was absent. In the absence of the repressor cI, the consistent expression of the Red recombination genes in prophages might result in more frequent gene exchanges, potentially increasing the probability of the acquisition of stx genes. We further investigated each of the 10 selected E. coli O157:H7 strains for their respective unique metabolic pathway genes. Seven unique metabolic pathway genes in the two stx2a-carrying strains and one in the single stx2c-carrying and seven stx-negative strains were found to be associated with an upstream insertion sequence 629 within a conserved region among these strains. The presence of more unique metabolic pathway genes in stx2a-carrying E. coli O157:H7 strains may potentially increase their competitiveness in complex environments, such as feedlot cattle. For the stx2c-carrying and stx-negative E. coli O157:H7 strains, the fact that they were grouped into the same phylogenomic cluster and had the same unique metabolic pathway genes suggested that they may also share closely related evolutionary pathways. As a consequence, gene exchange between them is more likely to occur. Results from this study could potentially serve as a basis to help develop strategies to reduce the prevalence of pathogenic E. coli O157:H7 in livestock and downstream food production environments.


2011 ◽  
Vol 55 (9) ◽  
pp. 4267-4276 ◽  
Author(s):  
Vinod Kumar ◽  
Peng Sun ◽  
Jessica Vamathevan ◽  
Yong Li ◽  
Karen Ingraham ◽  
...  

ABSTRACTThere is a global emergence of multidrug-resistant (MDR) strains ofKlebsiella pneumoniae, a Gram-negative enteric bacterium that causes nosocomial and urinary tract infections. While the epidemiology ofK. pneumoniaestrains and occurrences of specific antibiotic resistance genes, such as plasmid-borne extended-spectrum β-lactamases (ESBLs), have been extensively studied, only four complete genomes ofK. pneumoniaeare available. To better understand the multidrug resistance factors inK. pneumoniae, we determined by pyrosequencing the nearly complete genome DNA sequences of two strains with disparate antibiotic resistance profiles, broadly drug-susceptible strain JH1 and strain 1162281, which is resistant to multiple clinically used antibiotics, including extended-spectrum β-lactams, fluoroquinolones, aminoglycosides, trimethoprim, and sulfamethoxazoles. Comparative genomic analysis of JH1, 1162281, and other publishedK. pneumoniaegenomes revealed a core set of 3,631 conserved orthologous proteins, which were used for reconstruction of whole-genome phylogenetic trees. The close evolutionary relationship between JH1 and 1162281 relative to otherK. pneumoniaestrains suggests that a large component of the genetic and phenotypic diversity of clinical isolates is due to horizontal gene transfer. Using curated lists of over 400 antibiotic resistance genes, we identified all of the elements that differentiated the antibiotic profile of MDR strain 1162281 from that of susceptible strain JH1, such as the presence of additional efflux pumps, ESBLs, and multiple mechanisms of fluoroquinolone resistance. Our study adds new and significant DNA sequence data onK. pneumoniaestrains and demonstrates the value of whole-genome sequencing in characterizing multidrug resistance in clinical isolates.


2019 ◽  
Vol 14 (16) ◽  
pp. 1357-1367
Author(s):  
Jumamurat R Bayjanov ◽  
Miquel B Ekkelenkamp ◽  
Malbert RC Rogers ◽  
Rafael Cantón ◽  
Barry J Benaissa-Trouw ◽  
...  

Aim: Genetic characterization of Pandoraea strains recovered from cystic fibrosis patients. Materials & methods: The whole-genome sequence of 12 Pandoraea strains was determined using Illumina technology. The position of the strains within the genus Pandoraea was analyzed using selected partial gene sequences, core genome multi-locus sequence typing and average nucleotide identity analysis. Furthermore, the sequences were annotated. Results: The results show that some strains previously identified as Pandoraea pnomenusa, Pandoraea sputorum, Pandoraea oxalativorans and Pandoraea pulmonicola belong to novel species. The strains did not harbor acquired antibiotic resistance genes but encoded an OXA-type ß-lactamase. Conclusion: The taxonomy of the genus Pandoraea needs to be revised.


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