Phylogenetic Group Determination of Escherichia coli Isolated from Animals Samples.
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ABSTRACT:
SUBMITTER: Coura FM
PROVIDER: S-EPMC4572460 | biostudies-other | 2015
REPOSITORIES: biostudies-other
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Project description:Strains of urinary tract associated E. coli both recent isolates and from the ECOR collection and non pathogenic E. coli strains were analyzed. Replicates were performed to establish the reproduciblity, then single experiments were performed there on.
2023-07-27 | GSE235964 | GEO
Project description:Background:Fluoroquinolone resistant Escherichia coli isolates have become an important challenge in healthcare settings in Iran. In this study, we have determined Fluoroquinolone resistant E. coli isolates (from both outpatients and inpatients) and evaluated mutations of gyrA and parC within the quinolone resistance-determining regions (QRDR) of these clinical isolates. Materials and methods:Clinical isolates were recovered from the urine sample of patients with urinary tract infections admitted at Alzahra hospital, Iran, between September and February 2013. We assessed antimicrobial susceptibility of all isolates and determined mutations in QRDR of gyrA and parC genes from 13 fluoroquinolone-resistant isolates by DNA sequencing. Results:A total of 135 E. coli strains were obtained from 135 patients (91 outpatients and 44 inpatients). The resistance rate of fluoroquinolones (Ciprofloxacin, Norfloxacin and Ofloxacin) among our strains was 45.2%. Two E. coli isolates were shown just a single mutation, but other isolates possessed 2-5 mutations in gyrA and parC genes. Mutations in the QRDR regions of gyrA were at positions Ser83 and Asp87 and parC at positions Ser80, Glu84, Gly78. Conclusions:Ciprofloxacin is the most common antimicrobial agent used for treating urinary tract infections (UTIs) in healthcare settings in Iran. Accumulation of different substitutions in the QRDR regions of gyrA and parC confers high-level resistance of fluoroquinolones in clinical isolates.
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Project description:Escherichia coli (E. coli) is a zoonotic pathogen that often causes diarrhea, respiratory diseases or septicemia in animals. Fluoroquinolones are antimicrobial agents used to treat pathogenic E. coli infections. In this study, 1,221 E. coli strains were isolated between March, 2011 and February, 2014. The results of the antimicrobial susceptibility testing showed a high prevalence of quinolone resistance. The antimicrobial resistance rates of these E. coli isolates to nalidixic acid (NAL) were 72.0% in swine, 81.9% in chickens, 81.0% in turkeys, 64.0% in ducks and 73.2% in geese. Among these isolates, the positive rate for the plasmid-mediated quinolone resistance (PMQR) determinant was 14.8% (181/1,221); the detection rate for qnrS1 was the highest (10.2%), followed by aac(6')-Ib-cr (4.5%) and qnrB2 (0.3%). The quinolone-resistance determining regions (QRDRs) analysis for the PMQR-positive isolates showed that the strains with mutations at codon 83 or 87 in GyrA were resistant to NAL. To the best of our knowledge, this is the first report of occurrence of qnrB2, qnrS1 and aac(6')-Ib-cr genes and high frequency (56.4%; 102/181) of mutation in gyrA or parC among PMQR-positive E. coli strains derived from diseased animals in Taiwan.
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Project description:BackgroundClassification of pathogenic Escherichia coli (E. coli) has traditionally relied on detecting specific virulence associated genes (VAGs) or combinations thereof. For E. coli isolated from faecal samples, the presence of specific genes associated with different intestinal pathogenic pathovars will determine their classification and further course of action. However, the E. coli genome is not a static entity, and hybrid strains are emerging that cross the pathovar definitions. Hybrid strains may show gene contents previously associated with several distinct pathovars making the correct diagnostic classification difficult. We extended the analysis of routinely submitted faecal isolates to include known virulence associated genes that are usually not examined in faecal isolates to detect the frequency of possible hybrid strains.MethodsFrom September 2012 to February 2013, 168 faecal isolates of E. coli routinely submitted to the Norwegian Institute of Public Health (NIPH) from clinical microbiological laboratories throughout Norway were analysed for 33 VAGs using multiplex-PCR, including factors associated with extraintestinal pathogenic E. coli (ExPEC) strains. The strains were further typed by Multiple Locus Variable-Number Tandem-Repeat Analysis (MLVA), and the phylogenetic grouping was determined. One isolate from the study was selected for whole genome sequencing (WGS) with a combination of Oxford Nanopore's MinION and Illumina's MiSeq.ResultsThe analysis showed a surprisingly high number of strains carrying ExPEC associated VAGs and strains carrying a combination of both intestinal pathogenic E. coli (IPEC) and ExPEC VAGs. In particular, 93.5% (101/108) of isolates classified as belonging to an IPEC pathovar additionally carried ExPEC VAGs. WGS analysis of a selected hybrid strain revealed that it could, with present classification criteria, be classified as belonging to all of the Enteropathogenic Escherichia coli (EPEC), Uropathogenic Escherichia coli (UPEC), Neonatal meningitis Escherichia coli (NMEC) and Avian pathogenic Escherichia coli (APEC) pathovars.ConclusionHybrid ExPEC/IPEC E. coli strains were found at a very high frequency in faecal samples and were in fact the predominant species present. A sequenced hybrid isolate was confirmed to be a cross-pathovar strain possessing recognised hallmarks of several pathovars, and a genome heavily influenced by horizontal gene transfer.
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Project description:Comparison of Escherichia coli proteomics of different DNA sequence binding proteins and identification of heterologous expressed protein
2021-04-14 | PXD025380 |
Project description:Escherichia coli bacterioferritin was serendipitously crystallized in a novel cubic crystal form and its structure could be determined to 2.5 A resolution despite a high degree of merohedral twinning. This is the first report of crystallographic data on 'as-isolated' E. coli bacterioferritin. The ferroxidase active site contains positive difference density consistent with two metal ions that had co-purified with the protein. X-ray fluorescence studies suggest that the metal composition is different from that of previous structures and is a mix of zinc and native iron ions. The ferroxidase-centre configuration displays a similar flexibility as previously noted for other bacterioferritins.
| S-EPMC2225212 | biostudies-literature
Project description:Non-O157 Shiga toxin-producing Escherichia coli (STEC) is an important pathogen that can cause zoonotic diseases. To investigate the antimicrobial resistance of STEC in China, non-O157 STEC isolates, recovered from domestic animals and humans from 12 provinces, were analyzed using antimicrobial susceptibility testing and whole genome characterization. Out of the 298 isolates tested, 115 strains showed resistance to at least one antimicrobial and 85 strains showed multidrug resistance. The highest resistance rate was to tetracycline (32.6%), followed by nalidixic acid (25.2%) and chloramphenicol and azithromycin (both 18.8%). However, imipenem and meropenem were effective against all isolates. Antimicrobial resistance patterns varied among strains from different sources. Strains from pig, sheep, humans, and cattle showed resistance rates of 100.0%, 46.9%, 30.3%, and 6.3% to one or more antimicrobials, respectively. Forty-three genes related to 11 antimicrobial classes were identified among these strains. The colistin-resistance gene mcr was only carried by strains from pigs. A new fosfomycin-resistant gene, fosA7, was detected in strains from humans, cattle, and sheep. Whole genome phylogenetic analysis showed that strains from the four sources were genetically diverse and scattered throughout the phylogenetic tree; however, some strains from the same source had a tendency to cluster closely. These results provide a reference to monitor the emergence and spread of multidrug resistant STEC strains among animals and humans. Furthermore, with a better understanding of antimicrobial genotypes and phenotypes among the diverse STEC strains obtained, this study could guide the administration of antimicrobial drugs in STEC infections when necessary.
| S-EPMC7828786 | biostudies-literature
Project description:BackgroundEscherichia coli is an important pathogen that causes diarrhea in both humans and animals. To determine the relationships between putative virulence factors and pathotypes or host taxa, many molecular studies on diarrhea-associated E. coli have been reported. However, little is known regarding genome-wide variation of E. coli from animal hosts. In this study, we performed whole genome sequencing of 127 E. coli isolates from sheep and swine with diarrhea in China. We compared isolates to explore the phylogenomic relatedness based on host origin. We explored the relationships of putative virulence factors across host taxa and pathotypes. Antimicrobial resistance was also tested.ResultsThe E. coli genomes in this study were diverse with clear differences in the SNP, MLST, and O serotypes. Seven putative virulence factors (VFs) were prevalent (> 95%) across the isolates, including Hcp, csgC, dsdA, feoB, fepA, guaA, and malX. Sixteen putative VFs showed significantly different distributions (P < 0.05) in strains from sheep and swine and were primarily adhesion- and toxin-related genes. Some putative VFs were co-occurrent in some specific pathotypes and O serotypes. The distribution of 4525 accessory genes of the 127 strains significantly differed (P < 0.05) between isolates obtained from the two animal species. The 127 animal isolates sequenced in this study were each classified into one of five pathotypes: EAEC, ETEC, STEC, DAEC, and EPEC, with 66.9% of isolates belonging to EAEC. Analysis of stx subtypes and a minimum spanning tree based on MLST revealed that STEC isolates from sheep and EAEC isolates from sheep and swine have low potential to infect humans. Antibiotic resistance analysis showed that the E. coli isolates were highly resistant to ampicillin and doxycycline. Isolates from southeast China were more resistant to antibiotics than isolates from northwest China. Additionally, the plasmid-mediated colist in resistance gene mcr-1 was detected in 15 isolates, including 4 from sheep in Qinghai and 11 from swine in Jiangsu.ConclusionsOur study provides insight into the genomes of E. coli isolated from animal sources. Distinguishable differences between swine and sheep isolates at the genomic level provides a baseline for future investigations of animal E. coli pathogens.
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Project description:Shiga toxin-producing Escherichia coli (STEC) strains of the O91:H21 serotype have caused severe infections, including hemolytic-uremic syndrome. Strains of the O91 serogroup have been isolated from food, animals, and the environment worldwide but are not well characterized. We used a microarray and other molecular assays to examine 49 serogroup O91 strains (environmental, food, and clinical strains) for their virulence potential and phylogenetic relationships. Most of the isolates were identified to be strains of the O91:H21 and O91:H14 serotypes, with a few O91:H10 strains and one O91:H9 strain being identified. None of the strains had the eae gene, which codes for the intimin adherence protein, and many did not have some of the genetic markers that are common in other STEC strains. The genetic profiles of the strains within each serotype were similar but differed greatly between strains of different serotypes. The genetic profiles of the O91:H21 strains that we tested were identical or nearly identical to those of the clinical O91:H21 strains that have caused severe diseases. Multilocus sequence typing and clustered regularly interspaced short palindromic repeat analyses showed that the O91:H21 strains clustered within the STEC 1 clonal group but the other O91 serotype strains were phylogenetically diverse.IMPORTANCE This study showed that food and environmental O91:H21 strains have similar genotypic profiles and Shiga toxin subtypes and are phylogenetically related to the O91:H21 strains that have caused hemolytic-uremic syndrome, suggesting that these strains may also have the potential to cause severe illness.
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