scholarly journals Virulence Characteristics and Antimicrobial Resistance Profiles of Shiga Toxin-Producing Escherichia coli Isolates from Humans in South Africa: 2006–2013

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 424 ◽  
Author(s):  
Karama ◽  
Cenci-Goga ◽  
Malahlela ◽  
Smith ◽  
Keddy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South Africa ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Human Disease ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Marker Genes ◽  
Surveillance Programs ◽  
Monitoring And Surveillance

Shiga toxin-producing Escherichia coli (STEC) isolates (N = 38) that were incriminated in human disease from 2006 to 2013 in South Africa were characterized by serotype, virulence-associated genes, antimicrobial resistance and pulsed-field gel electrophoresis (PFGE). The isolates belonged to 11 O:H serotypes. STEC O26:H11 (24%) was the most frequent serotype associated with human disease, followed by O111:H8 (16%), O157:H7 (13%) and O117:H7 (13%). The majority of isolates were positive for key virulence-associated genes including stx1 (84%), eaeA (61%), ehxA (68.4%) and espP (55%), but lacked stx2 (29%), katP (42%), etpD (16%), saa (16%) and subA (3%). stx2 positive isolates carried stx2c (26%) and/or stx2d (26%) subtypes. All pathogenicity island encoded virulence marker genes were detected in all (100%) isolates except nleA (47%), nleC (84%) and nleD (76%). Multidrug resistance was observed in 89% of isolates. PFGE revealed 34 profiles with eight distinct clusters that shared ≥80% intra-serotype similarity, regardless of the year of isolation. In conclusion, STEC isolates that were implicated in human disease between 2006 and 2013 in South Africa were mainly non-O157 strains which possessed virulence genes and markers commonly associated with STEC strains that have been incriminated in mild to severe human disease worldwide. Improved STEC monitoring and surveillance programs are needed in South Africa to control and prevent STEC disease in humans.

Sorbitol non-fermenting shiga toxin-producingEscherichia coliin cattle on smallholdings

2014 ◽  
Vol 143 (1) ◽  
pp. 94-103 ◽  
Author(s):  
M. Z. ISLAM ◽  
J. P. CHRISTENSEN ◽  
P. K. BISWAS
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Shiga Toxin ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Chain Reaction ◽  
E Coli ◽  
Faecal Samples ◽  
Polymerase Chain

SUMMARYWe investigated faecal samples collected from the rectum of 518 cattle on 371 randomly selected smallholdings in Bangladesh for the presence of sorbitol non-fermenting (SN-F) shiga toxin-producingEscherichia coli(STEC). The SN-F isolates were tested for the presence ofrfbO157,stx1, stx2, eaeandhlyAgenes by polymerase chain reaction (PCR). Seven SN-F isolates lacking these genes were profiled by pulsed-field gel electrophoresis (PFGE) to verify their clonality. SN-FE. coliwas identified in 44 [8·5%, 95% confidence interval (CI) 6·4–11·2] samples; of these, 28 (5·4%, 95% CI 3·8–7·7) had shiga toxin-producing strains, although only two carried therfbO157 gene. Thirteen isolates carried thehlyAgene while 18 harboured theeaegene. Based on PFGE, six pulsotypes were observed among the seven isolates that had no virulence genes. To the best of our knowledge this is the first report on shiga toxin-producingE. colifrom direct rectal faecal samples of cattle on smallholdings.

scholarly journals Prevalence and Genetic Characterization of Shiga Toxin-Producing Escherichia coli Isolates from Slaughtered Animals in Bangladesh

2008 ◽  
Vol 74 (17) ◽  
pp. 5414-5421 ◽  
Author(s):  
Mohammad A. Islam ◽  
Abdus S. Mondol ◽  
Enne de Boer ◽  
Rijkelt R. Beumer ◽  
Marcel H. Zwietering ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Genetic Characterization ◽  
Clonal Diversity ◽  
Pulsed Field Gel Electrophoresis ◽  
E Coli ◽  
Phage Types ◽  
Distinct Restriction

ABSTRACT To determine the prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) in slaughter animals in Dhaka, Bangladesh, we collected rectal contents immediately after animals were slaughtered. Of the samples collected from buffalo (n = 174), cows (n = 139), and goats (n = 110), 82.2%, 72.7%, and 11.8% tested positive for stx 1 and/or stx 2, respectively. STEC could be isolated from 37.9%, 20.1%, and 10.0% of the buffalo, cows, and goats, respectively. STEC O157 samples were isolated from 14.4% of the buffalo, 7.2% of the cows, and 9.1% of the goats. More than 93% (n = 42) of the STEC O157 isolates were positive for the stx 2, eae, katP, etpD, and enterohemorrhagic E. coli hly (hly EHEC) virulence genes. STEC O157 isolates were characterized by seven recognized phage types, of which types 14 (24.4%) and 31 (24.4%) were predominant. Subtyping of the 45 STEC O157 isolates by pulsed-field gel electrophoresis showed 37 distinct restriction patterns, suggesting a heterogeneous clonal diversity. In addition to STEC O157, 71 STEC non-O157 strains were isolated from 60 stx-positive samples from 23.6% of the buffalo, 12.9% of the cows, and 0.9% of the goats. The STEC non-O157 isolates belonged to 36 different O groups and 52 O:H serotypes. Unlike STEC O157, most of the STEC non-O157 isolates (78.9%) were positive for stx 1. Only 7.0% (n = 5) of the isolates were positive for hly EHEC, and none was positive for eae, katP, and etpD. None of the isolates was positive for the iha, toxB, and efa1 putative adhesion genes. However, 35.2% (n = 25), 11.3% (n = 8), 12.7% (n = 9), and 12.7% (n = 9) of the isolates were positive for the lpf O113, saa, lpfA O157/01-141, and lpfA O157/OI-154 genes, respectively. The results of this study provide the first evidence that slaughtered animals like buffalo, cows, and goats in Bangladesh are reservoirs for STEC, including the potentially virulent STEC strain O157.

scholarly journals Virulence Genes in Expanded-Spectrum-Cephalosporin-Resistant and -Susceptible Escherichia coli Isolates from Treated and Untreated Chickens

2015 ◽  
Vol 60 (3) ◽  
pp. 1874-1877 ◽  
Author(s):  
S. Baron ◽  
S. Delannoy ◽  
S. Bougeard ◽  
E. Larvor ◽  
E. Jouy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Phylogenetic Groups ◽  
Content Type ◽  
E Coli ◽  
Heat Stable ◽  
Intestinal Infections

This study investigated antimicrobial resistance, screened for the presence of virulence genes involved in intestinal infections, and determined phylogenetic groups ofEscherichia coliisolates from untreated poultry and poultry treated with ceftiofur, an expanded-spectrum cephalosporin. Results show that none of the 76 isolates appeared to be Shiga toxin-producingE. colior enteropathogenicE. coli. All isolates were negative for the major virulence factors/toxins tested (ehxA,cdt, heat-stable enterotoxin [ST], and heat-labile enterotoxin [LT]). The few virulence genes harbored in isolates generally did not correlate with isolate antimicrobial resistance or treatment status. However, some of the virulence genes were significantly associated with certain phylogenetic groups.

scholarly journals Molecular characterization and antimicrobial resistance of STEC strains isolated from healthy cattle in 2011 and 2013 in Spain

2016 ◽  
Vol 144 (14) ◽  
pp. 2956-2966 ◽  
Author(s):  
A. CABAL ◽  
M. C. PORRERO ◽  
M. L. DE LA CRUZ ◽  
J. L. SAEZ ◽  
C. BARCENA ◽  
...  
Keyword(s):  
Public Health ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Gel Electrophoresis ◽  
Haemolytic Uraemic Syndrome ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Low Frequencies ◽  
Healthy Cattle ◽  
Foodborne Outbreaks

SUMMARYPrevention of Shiga toxin-producingEscherichia coli(STEC) foodborne outbreaks is hampered by its complex epidemiology. We assessed the distribution of virulence genes (VGs), main serogroups/serotypes for public health [haemolytic uraemic syndrome (HUS)-related], antimicrobial resistance (AMR) profiles and pulsed-field gel electrophoresis (PFGE) patterns in a collection of STEC isolates obtained from cattle hide (n= 149) and faecal (n= 406) samples collected during a national survey conducted in Spain in 2011 and 2013. Isolates were cultured using McConkey and CT-SMAC agar after enrichment, and confirmed as STEC by PCR. STEC prevalence in hides (15·4%) was higher than in faeces (10·7%) and O157:H7 was more frequent in the former (2·7%vs. 0·99%). Non-O157 HUS-related serogroups were present albeit at low frequencies. The non-O157 isolates were more heterogeneous than O157:H7 in their VG patterns, with 25/64 presenting VGs from both STEC and enterotoxigenic pathotypes (hybrid isolates). Of the STEC isolates, 62·5% were resistant at least to one antimicrobial, and no differences in AMR between O157:H7 and non-O157 were detected. All isolates had different profiles by PFGE and did not form a cluster. Overall, our results demonstrated that STEC in the cattle reservoir is still a matter of concern for human health due to the presence of HUS-related serogroups, the occurrence of certain VGs, AMR and the additional risks that hybrid isolates may pose, and thus warrants further investigation.

scholarly journals Molecular characterization of antimicrobial resistance and virulence genes of Escherichia coli isolates from bovine mastitis

2020 ◽  
Vol 13 (8) ◽  
pp. 1588-1593
Author(s):  
Zuhair Bani Ismail ◽  
Sameeh M. Abutarbush
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Procaine Penicillin

Background and Aim: Mastitis is a common and economically important disease in dairy cattle. It remains one of the most common reasons for the extensive use of antimicrobials in dairy farms leading to the emergence of antimicrobial-resistant pathogens. The aim of this study was to determine the patterns of antimicrobial resistance of Escherichia coli isolates from bovine mastitis and to identify prominent antimicrobial resistance and virulence genes among isolated strains. Materials and Methods: Antimicrobial susceptibility testing against six antibiotic groups, including tetracyclines, aminoglycosides, beta-lactams, macrolides, sulfonamides, and fluoroquinolones was performed using the disk diffusion method. PCR was performed on resistant isolates to detect resistance and virulence genes using commercially available primers. Results: Out of 216 milk samples cultured, 14 samples yielded E. coli isolates. All isolates (100%) were resistant to ampicillin, amoxicillin, procaine penicillin, streptomycin, oxytetracycline, and sulfamethoxazole-trimethoprim. Only one isolate (7%) was sensitive to gentamicin, and all isolates (100%) were sensitive to enrofloxacin and ciprofloxacin. All isolates carried at least one resistance gene against one or more of the major antibiotic groups. All isolates carried the ereA, tetG, tetE, and tetB genes, followed by tetA (93%), ampC (86%), strA (86%), sul1 (78%), tetD (71%), tetC (57%), aadA (57%), and strB (36%). The lowest percentage of isolates carried bla1 (17%) and bla2 (12%) genes, and none of the isolates carried the qnrA gene. Most of the isolates (93%) carried the Shiga toxin 1 virulence gene, followed by complement resistance protein (79%), intimin (64%), Shiga toxin 2 (36%), cytotoxic necrotizing factor (35%), aerotaxis receptor (21%), and type 1 fimbriae (15%). Conclusion: Results of this study indicate that the high percentages of E. coli isolate from bovine mastitis are resistant to two or more of the major antibiotic groups, irrespective of the presence or absence of relevant resistance or virulence genes.

scholarly journals Genetic and antimicrobial resistance profiles of non-O157 Shiga toxin-producing Escherichia coli from different sources in Egypt

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mohamed Sabry Abd Elraheam Elsayed ◽  
Samah Mahmoud Eldsouky ◽  
Tamer Roshdy ◽  
Abeer Mohamed Ahmed Bayoume ◽  
Ghada M. Nasr ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Variable Number Tandem Repeat ◽  
Low Frequency ◽  
Variable Number ◽  
Different Sources ◽  
High Range

Abstract Background The Shiga toxin-producing Escherichia coli (STEC) represented a great risk to public health. In this study, 60 STEC strains recovered from broiler and duck fecal samples, cow’s milk, cattle beef, human urine, and ear discharge were screened for 12 virulence genes, phenotypic and genotypic antimicrobial resistance, and multiple-locus variable-number tandem-repeat analysis (MLVA). Results The majority of strains harbored Shiga toxin 1 (stx1) and stx1d, stx2 and stx2e, and ehxA genes, while a minority harbored stx2c subtype and eaeA. We identified 10 stx gene combinations; most of strains 31/60 (51.7%) exhibited four copies of stx genes, namely the stx1, stx1d, stx2, and stx2e, and the strains exhibited a high range of multiple antimicrobial resistance indices. The resistance genes blaCTX-M-1 and blaTEM were detected. For the oxytetracycline resistance genes, most of strains contained tetA, tetB, tetE, and tetG while the tetC was present at low frequency. MLVA genotyping resolved 26 unique genotypes; genotype 21 was highly prevalent. The six highly discriminatory loci DI = 0.9138 are suitable for the preliminary genotyping of STEC from animals and humans. Conclusions The STEC isolated from animals are virulent, resistant to antimicrobials, and genetically diverse, thus demands greater attention for the potential risk to human.

scholarly journals Comparison of Common Enrichment Broths Used in Diagnostic Laboratories for Shiga Toxin—Producing Escherichia coli

2021 ◽  
Vol 9 (3) ◽  
pp. 503
Author(s):  
Michael Bording-Jorgensen ◽  
Hannah Tyrrell ◽  
Colin Lloyd ◽  
Linda Chui
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Acute Gastroenteritis ◽  
Diagnostic Testing ◽  
First Line ◽  
Gram Negative ◽  
Culture Independent ◽  
Surveillance Programs ◽  
Selection Of

Acute gastroenteritis caused by Shiga toxin-producing Escherichia coli (STEC) affects more than 4 million individuals in Canada. Diagnostic laboratories are shifting towards culture-independent diagnostic testing; however, recovery of STEC remains an important aspect of surveillance programs. The objective of this study was to compare common broth media used for the enrichment of STEC. Clinical isolates including O157:H7 as well as non-O157 serotypes were cultured in tryptic soy (TSB), MacConkey (Mac), and Gram-negative (GN) broths and growth was compared using culture on sheep’s blood agar and real-time PCR (qPCR). In addition, a selection of the same isolates was spiked into negative stool and enriched in the same three broths, which were then evaluated using culture on CHROMagarTM STEC agar and qPCR. TSB was found to provide the optimal enrichment for growth of isolates with and without stool. The results from this study suggest that diagnostic laboratories may benefit from enriching STEC samples in TSB as a first line enrichment instead of GN or Mac.

scholarly journals Genomic evolution of antimicrobial resistance in Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pimlapas Leekitcharoenphon ◽  
Markus Hans Kristofer Johansson ◽  
Patrick Munk ◽  
Burkhard Malorny ◽  
Magdalena Skarżyńska ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
Mobile Genetic Elements ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Metagenomic Sequencing ◽  
Fecal Samples ◽  
E Coli ◽  
Genetic Elements

AbstractThe emergence of antimicrobial resistance (AMR) is one of the biggest health threats globally. In addition, the use of antimicrobial drugs in humans and livestock is considered an important driver of antimicrobial resistance. The commensal microbiota, and especially the intestinal microbiota, has been shown to have an important role in the emergence of AMR. Mobile genetic elements (MGEs) also play a central role in facilitating the acquisition and spread of AMR genes. We isolated Escherichia coli (n = 627) from fecal samples in respectively 25 poultry, 28 swine, and 15 veal calf herds from 6 European countries to investigate the phylogeny of E. coli at country, animal host and farm levels. Furthermore, we examine the evolution of AMR in E. coli genomes including an association with virulence genes, plasmids and MGEs. We compared the abundance metrics retrieved from metagenomic sequencing and whole genome sequenced of E. coli isolates from the same fecal samples and farms. The E. coli isolates in this study indicated no clonality or clustering based on country of origin and genetic markers; AMR, and MGEs. Nonetheless, mobile genetic elements play a role in the acquisition of AMR and virulence genes. Additionally, an abundance of AMR was agreeable between metagenomic and whole genome sequencing analysis for several AMR classes in poultry fecal samples suggesting that metagenomics could be used as an indicator for surveillance of AMR in E. coli isolates and vice versa.

Sign in / Sign up

Export Citation Format

Share Document