scholarly journals Characterization of Shiga Toxin Gene (stx)-Positive and Intimin Gene (eae)-Positive Escherichia coli Isolates from Wastewater of Slaughterhouses in France

2006 ◽  
Vol 72 (5) ◽  
pp. 3245-3251 ◽  
Author(s):  
Estelle Loukiadis ◽  
Monique K�rour�dan ◽  
Lothar Beutin ◽  
Eric Oswald ◽  
Hubert Brug�re
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Wastewater Treatment Plants ◽  
Immunomagnetic Separation ◽  
Toxin Gene ◽  
E Coli ◽  
Treated Effluent ◽  
Colony Counting ◽  
Wastewater Samples

ABSTRACT Wastewater samples from 12 slaughterhouses located in different regions in France were tested for the presence of stx-positive and eae-positive Escherichia coli isolates, and characteristics of the isolates obtained were determined. A total of 224 wastewater samples were collected in wastewater treatment plants at different stages of wastewater processing. Altogether, 5,001 E. coli isolates were obtained by colony counting and screened for the presence of stx and eae genes by multiplex PCR. stx-positive and eae-positive E. coli isolates were detected in 25% of the samples collected; they were found in 13% and 3% of the samples obtained from treated effluent and sludge, respectively, suggesting that they could be spread into the environment. Screening of the samples collected by immunomagnetic separation allowed us to isolate 31 additional E. coli serogroup O157 isolates. Four of these isolates harbored stx and eae genes. All stx-positive and eae-positive E. coli isolates were analyzed for eae and stx genetic variants, as well as for additional virulence factors and serotypes. Our results suggest that the majority of the stx- and eae-positive E. coli isolates from wastewater have low virulence for humans. However, the diversity of the enterohemorrhagic E. coli-associated virulence factors in the strains indicates that the environment may play an important role in the emergence of new pathogenic enterohemorrhagic E. coli strains.

scholarly journals Development and Characterization of a Fluorescent-Bacteriophage Assay for Detection of Escherichia coli O157:H7

1999 ◽  
Vol 65 (4) ◽  
pp. 1397-1404 ◽  
Author(s):  
Lawrence Goodridge ◽  
Jinru Chen ◽  
Mansel Griffiths
Keyword(s):  
Escherichia Coli ◽  
Flow Cytometry ◽  
Immunomagnetic Separation ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Lower Detection ◽  
Unreliable Method ◽  
Direct Epifluorescent Filter Technique ◽  
Bacterial Concentrations

ABSTRACT In this paper we describe evaluation and characterization of a novel assay that combines immunomagnetic separation and a fluorescently stained bacteriophage for detection of Escherichia coliO157:H7 in broth. When it was combined with flow cytometry, the fluorescent-bacteriophage assay (FBA) was capable of detecting 104 cells/ml. A modified direct epifluorescent-filter technique (DEFT) was employed in an attempt to estimate bacterial concentrations. Using regression analysis, we calculated that the lower detection limit was between 102 and 103cells/ml; however, the modified DEFT was found to be an unreliable method for determining bacterial concentrations. The results of this study show that the FBA, when combined with flow cytometry, is a sensitive technique for presumptive detection of E. coliO157:H7 in broth cultures.

scholarly journals Characterization of virulence factors in Escherichia coli isolated from diarrheic and healthy calves in Austria shedding various enteropathogenic agents

2009 ◽  
Vol 54 (No. 1) ◽  
pp. 1-11 ◽  
Author(s):  
C. Herrera-Luna ◽  
D. Klein ◽  
G. Lapan ◽  
S. Revilla-Fernandez ◽  
B. Haschek ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Clostridium Perfringens ◽  
Shiga Toxin ◽  
Systemic Disease ◽  
Toxin Gene ◽  
Detection Rates ◽  
E Coli ◽  
Faecal Samples ◽  
Control And Prevention

Faecal samples from 230 diarrhoeic and healthy calves aged 0–6 weeks, from 100 farms in Austria, were examined between October 2004 and February 2005 for the presence of bacteria, especially Shiga toxin-producing <I>Escherichia coli </I> (STEC), viruses and parasites. <I>Escherichia coli</I> was detected in 17% of all the faecal samples and was more prevalent in healthy calves. However, <I>E. coli</I> F5 was identified only in one calf without diarrhoea. Overall, 35 out of the 230 (15.2%) samples analyzed carried the Shiga toxin gene: <I>stx1, stx2</I> or both <I>stx1</I> and<I> stx2</I> in their faeces, STEC. Nevertheless, out of 39 pathogenic <I>E. coli</I> positive samples observed, only two carried the Shiga toxin genes: <I>stx1</I>, in a diarrhoeic calf and both <I>stx1</I> and <I>stx2</I> in a healthy calf. <I>eaeA</I> and <I>Ehly</I> genes were detected more frequently in the strains from diarrhoeic calves 57.1% and 50.0%, respectively. <I>Clostridium perfringens</I> was detected in twenty-one samples, the most prevalent toxin type of <I>Clostridium perfringens</I> was found to be type A (76.2%). Other bacteria such as <I>Klebsiella</I> spp. and <I>Proteus</I> spp. were present in 1.3% and 0.4% of all samples. <I>Salmonella</I> spp. was not detected. The detection rates of other enteropathogens were 25.7% bovine coronavirus, 11.7% <I>Cryptosporidium</I> spp., 10.4% <I>Eimeria</I> spp., 9.1% group A rotavirus and <I>Giardia</I> spp. 6.1%. We demonstrated the presence of the STEC virulence genes in healthy and diarrhoeic Austrian calves but the importance of the virulence factors of STEC (<I>stx1, stx2, eae</I> and <I>Ehly</I>) in calf diarrhoea and systemic disease is not well defined. Therefore, further studies are necessary to identify reservoirs or potential sources of virulent STEC strains in order to establish control and prevention strategies for STEC associated diseases in animals and humans.

scholarly journals New Insight on Antibiotic Resistance and Virulence of Escherichia coli from Municipal and Animal Wastewater

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1111
Author(s):  
Gabriela Gregova ◽  
Vladimir Kmet ◽  
Tatiana Szaboova
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Multidrug Resistant ◽  
Wastewater Sample ◽  
E Coli ◽  
Animal Wastewater ◽  
Wastewater Samples ◽  
One Year

Antibiotic resistance of the indicator microorganism Escherichia coli was investigated in isolates from samples collected during the course of one year from two wastewater treatment plants treating municipal and animal wastes in Slovakia, respectively. The genes of antibiotic resistance and virulence factors in selected resistant E. coli isolates were described. A high percentage of the isolates from municipal and animal wastewater were resistant to ampicillin, streptomycin, tetracycline, ceftiofur, ceftriaxone, and enrofloxacin. In the selected E. coli isolates, we detected the following phenotypes: ESBL (20.4% in animal wastewater; 7.7% in municipal wastewater), multidrug-resistant (17% of animal and 32% of municipal isolates), high resistance to quinolones (25% of animal and 48% of municipal samples), and CTX-M (7.9% of animal and 17.3% of municipal isolates). We confirmed an integro-mediated antibiotic resistance in 13 E. coli strains from municipal and animal wastewater samples, of which the Tn3 gene and virulence genes cvaC, iutA, iss, ibeA, kps, and papC were detected in six isolates. One of the strains of pathogenic E. coli from the animal wastewater contained genes ibeA with papC, iss, kpsII, Int1, Tn3, and Cit. In addition, one blaIMP gene was found in the municipal wastewater sample. This emphasises the importance of using the appropriate treatment methods to reduce the counts of antibiotic-resistant microorganisms in wastewater effluent.

scholarly journals Detection and antibiotic susceptibility of pathogenic Escherichia coli isolated from the final effluent of two wastewater treatment Plants in the Eastern Cape Province, South Africa

2017 ◽  
Author(s):  
Osuolale Olayinka ◽  
Okoh Anthony
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Susceptibility ◽  
Wastewater Treatment Plants ◽  
Acquired Resistance ◽  
High Sensitivity ◽  
Water Sources ◽  
Eastern Cape ◽  
E Coli ◽  
Treated Effluent ◽  
Receiving Water

AbstractWastewater is an important reservoir for Escherichia coli and can present significant acute toxicity if released into receiving water sources without being adequately treated. To analyze whether pathogenic E. coli strains that cause infections are in treated effluent and to recognize antibiotic profile. 476 confirmed isolates from two treatment Plants were characterized for the presence of various E. coli pathotypes. A total of 8 pathotypes were screened and only four were confirmed. UPEC was about 5.7% followed by EAEC at 2.3%, NMEC at 1.1% and EPEC at 0.6%. Antibiotic susceptibility patterns of E. coli pathotypes such as UPEC showed low resistance to antibiotics like meropenem (100%), cefotaxime (100%) and gentamicin (88.9%). The pathotype also showed high degrees of resistance to tetracycline (74.1%), ampicillin (74.1%) and cephalothin (66.7%). Other E. coli pathotypes, EAEC, NMEC and EPEC, showed high sensitivity (100%) to meropenem, gentamicin and cefotaxime, and varying degree of resistances to ampicillin, tetracycline and cephalothin. The results of this study reveal that the two Plants discharge effluents with pathogenic E. coli and are reservoir for the bacteria into receiving water sources. In summary, this finding raises the possibility that at least some pathogenic E. coli pathotypes are getting into the environment through WWTPs and represent potential route for enteropathogenic infection. In addition, certain pathotypes may have acquired resistance properties, becoming a potential cause of drug resistance infection. This study reveals inadequacy of the plants studied to produce effluents of acceptable quality.

scholarly journals Presence of Putative Repeat-in-Toxin Gene tosA in Escherichia coli Predicts Successful Colonization of the Urinary Tract

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Patrick D. Vigil ◽  
Ann E. Stapleton ◽  
James R. Johnson ◽  
Thomas M. Hooton ◽  
Andrew P. Hodges ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Virulence Factors ◽  
Urinary Tract Infections ◽  
Murine Model ◽  
Toxin Gene ◽  
Content Type ◽  
E Coli ◽  
Tract Infections ◽  
Successful Colonization

ABSTRACTUropathogenicEscherichia coli(UPEC) strains, which cause the majority of uncomplicated urinary tract infections (UTIs), carry a unique assortment of virulence or fitness genes. However, no single defining set of virulence or fitness genes has been found in all strains of UPEC, making the differentiation between UPEC and fecal commensal strains ofE. colidifficult without the use of animal models of infection or phylogenetic grouping. In the present study, we consider three broad categories of virulence factors simultaneously to better define a combination of virulence factors that predicts success in the urinary tract. A total of 314 strains ofE. coli, representing isolates from fecal samples, asymptomatic bacteriuria, complicated UTIs, and uncomplicated bladder and kidney infections, were assessed by multiplex PCR for the presence of 15 virulence or fitness genes encoding adhesins, toxins, and iron acquisition systems. The results confirm previous reports of gene prevalence among isolates from different clinical settings and identify several new patterns of gene associations. One gene,tosA, a putative repeat-in-toxin (RTX) homolog, is present in 11% of fecal strains but 25% of urinary isolates. WhereastosA-positive strains carry an unusually high number (11.2) of the 15 virulence or fitness genes,tosA-negative strains have an average of only 5.4 virulence or fitness genes. The presence oftosAwas predictive of successful colonization of a murine model of infection, even among fecal isolates, and can be used as a marker of pathogenic strains of UPEC within a distinct subset of the B2 lineage.IMPORTANCEEscherichia coliis the primary cause of urinary tract infections, the most common bacterial infection of humans. Virulence of a uropathogenic strain is typically defined by the clinical source of the isolate, the ability to colonize the bladder and kidneys in a murine model, the phylogenetic group of the bacterium, and virulence gene content. Here we describe a novel single gene, the repeat-in-toxin genetosA, the presence of which predicts virulence ofE. coliisolates regardless of source. Rapid identification of uropathogenic strains ofE. colimay aid in the development of therapeutic and preventive therapies.

scholarly journals Molecular characterization of virulence factors in diarrhoeagenic Escherichia coli isolates from children in Nairobi, Kenya.

2012 ◽  
Vol 6 (08) ◽  
pp. 598-604 ◽  
Author(s):  
Celestine Khalechi Makobe ◽  
Willie K Sang ◽  
Gideon Kikuvi ◽  
Samuel Kariuki
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Public Health Problem ◽  
Etiologic Agent ◽  
Major Public Health Problem ◽  
Conventional Pcr ◽  
E Coli ◽  
Enterocyte Effacement ◽  
New Evidence

Introduction: Among the bacterial causes, diarrheagenic Escherichia coli (DEC) is the most important etiologic agent of childhood diarrhoea and represents a major public health problem in developing countries. New evidence suggests that major differences in virulence among groups of DEC pathotypes may be related to the presence of specific pathogenicity islands (PAIs). Methodology: Multiplex and conventional PCR assays were used to identify the DEC pathotypes and PAIs respectively from 207 E. coli isolates. Results: The predominant DEC pathotype isolated was EPEC 19.3% (40/207), followed by ETEC 7.25% (15/207), EAEC 3.86% (8/207), STEC 0.97% (2/207) and EIEC 0.48% (1/207). The PAIs detected were enteropathogenic secreted protein C (EspC) 12.2% (8/66), locus of enterocyte effacement (LEE) 62.1% (41/66), and high pathogenicity island (HPI) 57.6% (38/66). Six percent (4/66) expressed only fyuA gene, 12.2% (8/66) irp2 only, and 39.4% (26/66) expressed both fyuA and irp2 genes. SHI-2 39.4% (26/66), she 6% (4/66) and O island 33.3% (22/66), 19.8% (13/66) expressed only efa/lifA gene, 7.6% (5/66) pagC gene only and 6.1% (4/66) expressed both efa/lifA and pagC genes. Toxigenic invasion A (TIA) PAI was not detected. Conclusion: This study revealed that in addition to eaeA, stx, aat, einv, st and lt virulence genes exhibited in the different DEC pathotypes there are numerous PAIs in the DEC pathotypes. The PAIs can increase gene mobility within various motile elements, which has implications for the spread of virulence factors from DEC to commensal E. coli.

scholarly journals Phenotypic and genotypic characterization of Escherichia coli O157 strains isolated from humans, cattle and pigs

2012 ◽  
Vol 49 (No. 9) ◽  
pp. 317-326 ◽  
Author(s):  
J. Osek
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Biochemical Properties ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Phenotypic Data ◽  
Shiga Toxins ◽  
E Coli ◽  
Biochemical Profiles

A total of 90 Escherichia coli O157 isolates recovered from humans, cattle, and pigs, were examined for the presence of the H7 antigen, ability to produce Shiga toxins and enterohemolysin as well as for antimicrobial resistance and biochemical properties. Fourteen of the human strains (n = 23) and 21 of the bovine isolates (n&nbsp;=&nbsp;29) were of the O157:H7 serotype as determined by agglutination and PCR methods. All E. coli O157 of porcine origin (n&nbsp;=&nbsp;38) were H-negative. Based on the ability to produce Shiga toxins (Stxs), all human and cattle isolates and 11&nbsp;strains recovered from swine were identified as Shiga toxin-producing E. coli (STEC). Among STEC, most human strains (18 isolates) were Stx1- and Stx2-positive whereas cattle strains were mostly Stx2-positive. Eleven porcine STEC produced either Stx1 (7 isolates) or Stx2 (4 strains) toxins; an additional 20 isolates recovered from these animals had the Stx2e toxin gene as previously determined by PCR. All human and cattle E. coli O157 produced enterohemolysin whereas only 4 strains recovered from pigs were ehly-positive. Moreover, the PCR identification of the lpf<sub>O113</sub> gene performed earlier revealed that this putative virulence marker was present in all porcine isolates, only in 5 strains of bovine origin but in none of E. coli O157 recovered from humans. All 90 E. coli O157 strains tested displayed 10&nbsp;biochemical profiles that were different at least in one of the reaction tested. The most common atypical reaction observed among porcine O157 isolates was ability to ferment sorbitol (all strains) and production of &beta;-glucuronidase (25 isolates). Moreover, none of the sorbitol-positive strains was able to produce indol. Four antimicrobial resistance profiles among 90 E. coli O157 strains tested were observed. Most of the isolates recovered from humans and all strains from cattle were resistant only to rifampicin whereas the porcine strains showed resistance to either 3 antimicrobials (4 isolates) or to 4 drugs tested (34 isolates). The phenotypic data shown in the present study, together with the previously published genotypic analyses of these strains, confirm earlier suggestions that the porcine E. coli O157 strains are mostly different from those of bovine and human O157 isolates and could therefore play less important role in human STEC O157 infections.

Isolation and Characterization of the Shiga Toxin Gene (stx)–Bearing Escherichia coli O157 and Non-O157 from Retail Meats in Shandong Province, China, and Characterization of the O157-Derived stx2 Phages

2008 ◽  
Vol 71 (4) ◽  
pp. 706-713 ◽  
Author(s):  
TSUTOMU KOITABASHI ◽  
SHAN CUI ◽  
MUHAMMAD KAMRUZZAMAN ◽  
MITSUAKI NISHIBUCHI
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Shandong Province ◽  
Toxin Gene ◽  
Immunomagnetic Bead ◽  
E Coli ◽  
Isolation And Characterization ◽  
Retail Meats ◽  
Q Gene

Infection by Shiga toxin (Stx)–producing Escherichia coli of non-O157 and O157 serotypes are rare in China, but infection by O157 serotype was found in Shandong Province and three other provinces in China. To understand the reason for these rare infections and to determine the safety of retail meats in Shandong Province, we examined the distribution of Shiga toxin gene (stx)–bearing E. coli in retail meats and characterized the isolated stx-bearing strains. We used hybridization with DNA probes and isolated stx1- and/or stx2-positive E. coli from 31 (58%) of 53 retail meat samples, with beef showing the highest frequency (68%). Of 42 stx-positive isolates, none belonged to O157. Using the O157-specific immunomagnetic bead technique, we isolated E. coli O157 carrying the eae and stx2 genes from eight beef samples (26%). These strains produced little or no Stx2 and carried a unique q gene. Replication of the stx2 phages was detected in these strains, whereas stx2 phage replication was not detected in our previous study in which we examined similar stx2-bearing E. coli O157 strains from other Asian countries. Analysis of E. coli C600 lysogenized with the stx2 phages found in this study suggests that the lack of Stx2 production is due to changes in non-q gene region(s) of the phage genome or chromosomal mutation(s) in the host. Our data and reports by other workers suggest it is necessary to determine if various stx2-bearing E. coli O157 strains producing Stx2 to varying degrees are distributed in meats in various locations in China.

Molecular Characterization of Escherichia coli O157 Contamination Routes in a Cattle Slaughterhouse

2003 ◽  
Vol 66 (9) ◽  
pp. 1564-1569 ◽  
Author(s):  
ANN V. TUTENEL ◽  
DENIS PIERARD ◽  
JAN VAN HOOF ◽  
LIEVEN DE ZUTTER
Keyword(s):  
Escherichia Coli ◽  
Immunomagnetic Separation ◽  
Escherichia Coli O157 ◽  
Anal Region ◽  
E Coli ◽  
The Third ◽  
Selective Plating ◽  
Contamination Routes ◽  
Pfge Profiles

In a cattle slaughterhouse, sampling was performed over a 1-week period to examine the prevalence and possible contamination routes of Escherichia coli O157. Each sampling day, swab samples were collected from the slaughterhouse environment before onset of slaughter, from the slaughterline, and from 20 successively slaughtered animals. Isolation of E. coli O157 consisted of a 6-hour enrichment followed by immunomagnetic separation and selective plating. From the 394 samples taken, 84 (21%) were positive for E. coli O157. Pulsed-field gel electrophoresis (PFGE) of collected isolates produced 26 different profiles, from which 5 PFGE profiles carried two or more Stx genes. The combination of PFGE profiles and Stx types resulted in 32 different E. coli O157 types. E. coli O157 was found in the slaughterhouse environment before the onset of slaughter. The first two sampling days, feces and carcasses were found negative. On the third sampling day, five fecal samples and four carcasses from animals negative in the feces were positive. Hide of the anal region and the shoulder were found positive every sampling day. The shoulder hide was more than twice as contaminated as the anal region hide. Typing of different isolates from a sample showed that frequently different E. coli O157 types were presented. On sampling days 1 and 2, types present in the environment and on the hides of the slaughtered animals differed. On the third sampling day, two dominant types were found in the environment (even before the onset of slaughter), as well as on the hides, feces, and carcasses. Although examined animals originated from different farms, one (two on day 3) dominant E. coli O157 type was present on their hides each sampling day. These data indicated that (i) the progress of contamination can differ from day to day within a slaughterhouse and (ii) contact between animals after the departure from the farm can have a large effect on the spread of E. coli O157 hide contamination.

Characterization of Colicinogenic Escherichia coli Strains Inhibitory to Enterohemorrhagic Escherichia coli

2004 ◽  
Vol 67 (3) ◽  
pp. 486-492 ◽  
Author(s):  
GERRY P. SCHAMBERGER ◽  
FRANCISCO DIEZ-GONZALEZ
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Food Safety ◽  
Virulence Factors ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Strain Collection ◽  
Safety Intervention

A previously identified set of anti– Escherichia coli O157:H7 colicinogenic E. coli were characterized to assess the suitability of these isolates as a preharvest food safety intervention in cattle. This collection of 23 E. coli strains were screened for virulence factors, antibiotic resistance, type of colicin(s) present, and their ability to inhibit other pathogenic E. coli. With the use of PCR, pathogen genes were detected in six of the 23 colicinogenic E. coli. When the nonpathogenic strains were assessed for antibiotic resistance, four strains showed resistance to at least one antibiotic. The remaining set of 14 strains were evaluated for the presence of previously identified colicins. Seven colicins (B, E1, E2/E7, E7, Ia/Ib, K, and M) were detected. One half of the strains possessed multiple types of colicins. The most commonly detected colicins were B, E2/E7, and M, which were found in six strains each. DNA sequencing was also performed in order to classify the E2/E7 colicins separately from E7 colicins. The 14 colicinogenic E. coli also were evaluated for their ability to inhibit 10 different non-O157 pathogenic E. coli. Six of the colicinogenic E. coli were capable of inhibiting all 10 pathogens, and the remaining eight strains could each inhibit between six to eight of the pathogenic E. coli. This strain collection has great potential for inhibiting E. coli O157:H7 in cattle.

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