scholarly journals Detection of Several Virulence Properties, Antibiotic Resistance and Phylogenetic Relationship in E. Coli Isolates Originated from Cow Mastitis

2014 ◽  
Vol 64 (4) ◽  
pp. 413-425 ◽  
Author(s):  
Cengiz Seyda ◽  
Dinç Gökçen ◽  
Söğüt Mehtap Ünlü
Keyword(s):  
Antibiotic Resistance ◽  
Shiga Toxin ◽  
Clinical Signs ◽  
Clinical Mastitis ◽  
Pcr Analysis ◽  
Toxin Gene ◽  
Intramammary Infections ◽  
E Coli ◽  
Shiga Toxin Genes ◽  
Virulence Properties

Abstract Cow mastitis caused by Escherichia coli (E. coli) exhibits various local and systemic clinical signs at varying degrees of severity. The aim this study was to elucidate the virulence properties, antibiotic resistance and phylogenetics of 56 E. coli strains. Of all the studied strains, 12 were positive for hemolytic properties and 38 were positive for biofilm production. Additionally, 55 of the strains were positive for multiple resistances in bacteriological tests. PCR analysis revealed that 42 strains carried the traT gene, 20 strains had the shiga toxin gene (stx1-stx2), and 8 strains carried the intimin gene (eae), but all strains were negative for aerobactin gene (aer). All strains encoding shiga toxin genes were also positive for stx1, but only 4 strains were positive for stx2. There were no significant differences in virulence genes between antibiotic-resistant and antibiotic-susceptible strains. The random amplifi ed polymorphic DNA-polymerase chain reaction patterns revealed the existence of 13 main groups with 4 subgroups of E. coli. In this study, E. coli strains causing intramammary infections and originating from various sources might show resistance against common antibiotics. Pathogenity of E. coli that cause clinical mastitis, and prognosis of the infection might be predicted by obtaining the traT gene. Additionally, antibiotic resistance should be investigated at the genomic level to detect the relationship between virulence factors and antibiotic resistance. In field conditions, development of antibiotic resistance is the main cause of mastitis treatment failure. Thus, antibiotic resistance profiles in herds should be monitored and effective antibiotics should be administered

scholarly journals Molecular analysis of Escherichia coli O157 strains isolated from cattle and pigs by the use of PCR and pulsed-field gel electrophoresis methods

2012 ◽  
Vol 47 (No. 6) ◽  
pp. 149-158 ◽  
Author(s):  
J. Osek ◽  
P. Gallien
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Genetic Relatedness ◽  
Rflp Analysis ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Chromosomal Dna ◽  
E Coli ◽  
Shiga Toxin Genes ◽  
Porcine Origin

Fourteen Escherichia coli O157 strains isolated from cattle and pigs in Poland and in Germany were investigated, using PCR, for the genetic markers associated with Shiga toxin-producing E. coli (STEC). Only two strains, both of cattle origin, were positive for the fliC (H7) gene and could be classified as O157 : H7. Nine isolates had stx shiga toxin genes, either stx1 (1 strain), stx2 (4 isolates) or both (4 strains). The stx2-carrying samples were further subtyped by PCR for the stx2c, stx2d, and stx2e toxin variants. It was shown that all but one stx2-positive bacteria possessed the stx2c Shiga toxin gene type and one stx2 STEC isolate had the stx2d virulence factor sub-type. The eaeA (intimin) gene was found in 9 strains (8 isolates from cattle and one strain from pigs); all of them harboured the genetic marker characteristic of the gamma intimin variant. The translocated intimin receptor (tir) gene was detected in 7 isolates tested and among them only one tir-positive strain was recovered from pigs. The ehly E. coli enterohemolysin gene was amplified in all but one strains obtained from cattle and only in one isolate of porcine origin. The genetic relatedness of the analysed E. coli O157 strains was examined by restriction fragment length polymorphism (RFLP) of chromosomal DNA digested with XbaI. Two distinct but related RFLP pattern clusters were observed: one with 9 strains (8 isolates of bovine origin and one strain obtained from pigs) and the other one comprises the remaining 5 E. coli isolates (4 of porcine origin and one strain recovered from cattle). The results suggest that pigs, besides cattle, may be a reservoir of E. coli O157 strains potentially pathogenic to humans. Moreover, epidemiologically unrelated isolates of the O157 serogroup, recovered from different animal species, showed a clonal relationship as demonstrated by the RFLP analysis.

scholarly journals The prevalence and genomic context of Shiga toxin 2a genes in E. coli found in cattle

2020 ◽  
Author(s):  
Tomas Jinnerot ◽  
Angeles Tatiana Ponton Tomaselli ◽  
Gro S Johannessen ◽  
Robert Söderlund ◽  
Anne Margrete Urdahl ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Severe Disease ◽  
Amplicon Sequencing ◽  
Toxin Gene ◽  
Genomic Context ◽  
E Coli ◽  
Faecal Samples ◽  
Cattle Herds ◽  
Shiga Toxin Genes

AbstractShiga toxin-producing Escherichia coli (STEC) that cause severe disease predominantly carry the toxin gene variant stx2a. However, the role of Shiga toxin in the ruminant reservoirs of this zoonotic pathogen is poorly understood and strains that cause severe disease in humans (HUSEC) likely constitute a small and atypical subset of the overall STEC flora. The aim of this study was to investigate the presence of stx2a in samples from cattle and to isolate and characterize stx2a-positive E. coli. In nationwide surveys in Sweden and Norway samples were collected from individual cattle or from cattle herds, respectively. Samples were tested for Shiga toxin genes by real-time PCR and amplicon sequencing and stx2a-positive isolates were whole genome sequenced. Among faecal samples from Sweden, stx1 was detected in 37%, stx2 in 53% and stx2a in 5% and in skin samples in 64%, 79% and 2% respectively. In Norway, 79% of the herds were positive for stx1, 93% for stx2 and 17% for stx2a. Based on amplicon sequencing the most common stx2 types in samples from Swedish cattle were stx2a and stx2d. Multilocus sequence typing (MLST) of 39 stx2a-positive isolates collected from both countries revealed substantial diversity with 19 different sequence types. Only a few classical LEE-positive HUSEC were found among the stx2a-positive isolates, notably a single O121:H19 and an O26:H11. Known LEE-negative HUSEC lineages were also recovered including O113:H21 (ST-223), O130:H11 (ST-297), and O101:H33 (ST-330). We conclude that E. coli encoding stx2a in cattle are ranging from well-known HUSEC to unknown STEC variants. Comparison of isolates from human HUS cases to related STEC from the ruminant reservoirs can help identify combinations of virulence attributes necessary to cause HUS, as well as provide a better understanding of the routes of infection for rare and emerging pathogenic STEC.

scholarly journals PREVALENCE OF ENTEROHAEMORRHAGIC ESCHERICHIA COLI O157:H7, SHIGA TOXIN GENES AND ANTIBIOTIC RESISTANCE IN CHILDREN AGED 0-5 YEARS WITH DIARRHOEA IN IBADAN, OYO STATE

2020 ◽  
Vol 10 ◽  
pp. 171
Author(s):  
Anotu Mopelola Deji-Agboola ◽  
Florence Adenike Bamigbola ◽  
Olubunmi Adetokunbo Osinupebi
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Shiga Toxin ◽  
E Coli ◽  
Enterohaemorrhagic Escherichia Coli ◽  
Hand Wash ◽  
Stool Samples ◽  
Antibiotics Susceptibility ◽  
Shiga Toxin Genes ◽  
Cultured Bacteria

Diarrhoea is a predominant cause of childhood illness and death, Enterohaemorrhagic Escherichia  coli (EHEC) have increasingly been recognised as an important cause of diarrhea all over the world. This study investigates the prevalence, presence of shiga toxin (Stx) and antibiotic resistance of Enterohaemorrhagic  Escherichia  coli (EHEC) O157:H7 in children with diarrhoea. Stool samples collected from children less than five year with diarrhoea were cultured, bacteria isolated were identified and antibiotics susceptibility testing was performed using standard methods. Entrohaemorrhagic E. coli O157:H7 and Stx were screened using serology and Polymerase Chain Reaction respectively. Structured questionnaires were administered to determine factors that predispose the children to diarrhoea. A total of 301/370 (81.4%) stool samples yielded bacterial growth, 261/301 (86.7%) were gram negative bacilli, 188/261 (72.0%) Escherichia coli, 163/188 (86.7%) were EHEC O157: H7. Out of the 5 EHEC O157:H7 only 2 possessed Stx genes, 1 have Stx 2 while the other have both Stx 1 and Stx 2 gene. Escherichia coli were resistant to Tetracycline 98.4%, Ampicillin 83.0%, Cefuroxime 76.5%, Augmentin 62.9% and Gentamycin 51.4%, all the EHEC O157:H7 were resistant to Tetracycline and Ampicillin. Diarrhoea in the children were significantly associated with hand wash after toilet, eating pastries, sources of drinking water and the educational level of parent/caretaker (p-values = 0.04, 0.00, 0.00 and 0.03 respectively). The presence of EHEC O157:H7 carrying Stx 1 and Stx 2 gene as well as resistant to all antibiotics tested is a pointer for more stringent and better screening for diarrhoea infections in children.

scholarly journals Virulence Factors and Antibiotic Resistance of Escherichia coli O157:H7 Isolated from Ogun River, Abeokuta Metropolis, Nigeria

2019 ◽  
pp. 22-30
Author(s):  
Lateefat M. Ewuoso ◽  
Saka A. Balogun ◽  
Sarafadeen O. Kareem ◽  
Temilade F. Akinhanmi
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Latex Agglutination ◽  
Diffusion Method ◽  
Pcr Analysis ◽  
E Coli ◽  
Multiple Drugs ◽  
Ogun River

Although Escherichia coli (E. coli)is a harmless gut microbe in man, some strains of this bacterium are pathogenic due to the acquisition of virulence factors. The aim of this study isto investigate E. coli O157:H7 strains isolated from Ogun River, Abeokuta metropolis, for virulence factors and antibiotic resistance. Water samples were collected bimonthly from six different locations over a period of six months. The samples were cultured on Sorbitol MacConkey Agar and E. coli O157:H7 isolates were confirmed through serological characterization using the latex agglutination test. The presence of virulence genes (stx1, stx2, eae, and hylA) in the isolates was analyzed through polymerase chain reaction (PCR). Further, antibiotic susceptibility of the isolates was tested using the disc diffusion method. The PCR analysis revealed that the five E. coli O157:H7 strains isolated possessed Shiga toxin 1 (stx1), Shiga toxin 2 (stx2), and Haemolysin (hlyA) genes. Additionally, the isolates were resistant to Augmentin, Ceftriaxone, Nitrofurantoin, Gentamycin, Amoxicillin, and Pefloxacin. This study shows that E. coli O157:H7 strains are present in Ogun River and that these strains possess multiple virulence factors and are resistant to multiple drugs.

scholarly journals Comparison between human and animal isolates of Shiga toxin-producing Escherichia coli O157 from Australia

2002 ◽  
Vol 128 (3) ◽  
pp. 357-362 ◽  
Author(s):  
N. FEGAN ◽  
P. DESMARCHELIER
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Human Infection ◽  
Pulsed Field Gel Electrophoresis ◽  
Toxin Gene ◽  
Escherichia Coli O157 ◽  
Animal Population ◽  
E Coli ◽  
Virulence Markers ◽  
Animal Isolates

There is very little human disease associated with enterohaemorrhagic Escherichia coli O157 in Australia even though these organisms are present in the animal population. A group of Australian isolates of E. coli O157:H7 and O157:H- from human and animal sources were tested for the presence of virulence markers and compared by XbaI DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). Each of 102 isolates tested contained the gene eae which encodes the E. coli attaching and effacing factor and all but one carried the enterohaemolysin gene, ehxA, found on the EHEC plasmid. The most common Shiga toxin gene carried was stx2c, either alone (16%) or in combination with stx1 (74%) or stx2 (3%). PFGE grouped the isolates based on H serotype and some clusters were source specific. Australian E. coli O157:H7 and H- isolates from human, animal and meat sources carry all the virulence markers associated with EHEC disease in humans therefore other factors must be responsible for the low rates of human infection in Australia.

Detection, enumeration and isolation of strains carrying the stx2 gene from urban sewage

2003 ◽  
Vol 47 (3) ◽  
pp. 109-116 ◽  
Author(s):  
A.R. Blanch ◽  
C. García-Aljaro ◽  
M. Muniesa ◽  
J. Jofre
Keyword(s):  
Shiga Toxin ◽  
Colony Growth ◽  
Coliform Bacteria ◽  
Shiga Toxins ◽  
E Coli ◽  
Urban Sewage ◽  
Shiga Toxin 2 ◽  
Shiga Toxin Genes ◽  
Lateral Transmission ◽  
Stx2 Gene

Verotoxigenic Escherichia coli strains have been related with waterborne outbreaks. Besides 0157:H7, several serotypes of E. coli and other enterobacteria have been implicated in outbreaks and reported to carry the shiga toxin genes. Shiga toxins, stx1 and stx2, are important virulence factors of these strains. These genes have been linked to bacteriophages and consequently are susceptible to lateral transmission. To better understand the ecology of these genes a study of the presence of the shiga toxin 2 gene (stx2) among coliform bacteria present in sewage samples was carried out. A procedure based on colony hybridisation was developed for the isolation of enterobacteria carrying this gene. Colony growth on Chromocult® agar was transferred to a membrane and hybridised with a gene specific probe. The procedure allowed detection of about one colony carrying the gene among around 1,000 faecal coliform colonies. The numbers of bacteria carrying the gene in sewage were also estimated by PCR indicating that the numbers of bacteria carrying the stx2 gene were about 1/1,000 faecal coliforms. The detected numbers by both methods were similar. Positive colony hybridisation was detected in four sewage origins. Fifty-two colonies showing positive signal were isolated from the Chromocult® agar plates, confirmed to be stx2 positive by PCR and phenotypically characterised. Results of the characterisation showed certain diversity among the isolates even in isolates from the same sample. Most of these isolates would not have been isolated with the methods regularly used for the isolation of E. coli 0157:H7 strains. The method will allow study of the numbers and characteristics of bacteria carrying the stx2 gene in different water environments and isolate them in order to determine their role in the spread of the gene.

Presence and Antimicrobial Resistance of Escherichia coli in Ready-to-Eat Foods in Shaanxi, China

2017 ◽  
Vol 80 (3) ◽  
pp. 420-424 ◽  
Author(s):  
Allah Bux Baloch ◽  
Hua Yang ◽  
Yuqing Feng ◽  
Meili Xi ◽  
Qian Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Shaanxi Province ◽  
Future Research ◽  
E Coli ◽  
Class 1 Integrons ◽  
Toxin Genes ◽  
Class 1 ◽  
Shiga Toxin Genes ◽  
Cooked Meat

ABSTRACT The aim of this study was to determine the presence and characteristics of Escherichia coli in ready-to-eat (RTE) foods. A total of 300 RTE foods samples were collected in Shaanxi Province, People's Republic of China: 50 samples of cooked meat, 165 samples of vegetable salad, 50 samples of cold noodles, and 35 samples of salted boiled peanuts. All samples were collected during summer (in July to October) 2011 and 2012 and surveyed for the presence of E. coli. E. coli isolates recovered were classified by phylogenetic typing using a PCR assay. The presence of Shiga toxin genes 1 (stx1) and 2 (stx2) was determined for these E. coli isolates by PCR, and all isolates were analyzed for antimicrobial susceptibility and the presence of class 1 integrons. Overall, 267 (89.0%) RTE food samples were positive for E. coli: 49 cold noodle, 46 cooked meat, 150 salad vegetable, and 22 salted boiled peanut samples. Of the 267 E. coli isolates, 73.0% belong to phylogenetic group A, 12.4% to group B1, 6.4% to group B2, and 8.2% to group D. All isolates were negative for both Shiga toxin genes. Among the isolates, 74.2% were resistant to at least one antimicrobial agent, and 17.6% were resistant to three or more antimicrobial agents. Resistance to ampicillin (75.6% of isolates) and tetracycline (73.1% of isolates) was most frequently detected; 26.2% of E. coli isolates and 68.8% of multidrug-resistant E. coli isolates were positive for class 1 integrons. All isolates were sensitive to amikacin. Our findings indicate that RTE foods in Shaanxi were commonly contaminated with antibiotic-resistant E. coli, which may pose a risk for consumer health and for transmission of antibiotic resistance. Future research is warranted to track the contamination sources and develop appropriate steps that should be taken by government, industry, and retailers to reduce microbial contamination in RTE foods.

scholarly journals Virulence Characteristics and Antibiotic Resistance Profiles of Shiga Toxin-Producing Escherichia coli Isolates from Diverse Sources

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 587
Author(s):  
Momna Rubab ◽  
Deog-Hwan Oh
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Shiga Toxin ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Diffusion Method ◽  
Shiga Toxins ◽  
E Coli ◽  
And Control ◽  
High Degree

Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen that causes several gastrointestinal ailments in humans across the world. STEC’s ability to cause ailment is attributed to the presence of a broad range of known and putative virulence factors (VFs) including those that encode Shiga toxins. A total of 51 E. coli strains belonging to serogroups O26, O45, O103, O104, O113, O121, O145, and O157 were tested for the presence of nine VFs via PCR and for their susceptibility to 17 frequently used antibiotics using the disc diffusion method. The isolates belonged to eight different serotypes, including eight O serogroups and 12 H types. The frequency of the presence of key VFs were stx1 (76.47%), stx2 (86.27%), eae (100%), ehxA (98.03%), nleA (100%), ureC (94.11%), iha (96.07%), subA (9.80%), and saa (94.11%) in the E. coli strains. All E. coli strains carried seven or more distinct VFs and, among these, four isolates harbored all tested VFs. In addition, all E. coli strains had a high degree of antibiotic resistance and were multidrug resistant (MDR). These results show a high incidence frequency of VFs and heterogeneity of VFs and MDR profiles of E. coli strains. Moreover, half of the E. coli isolates (74.5%) were resistant to > 9 classes of antibiotics (more than 50% of the tested antibiotics). Thus, our findings highlight the importance of appropriate epidemiological and microbiological surveillance and control measures to prevent STEC disease in humans worldwide.

scholarly journals Molecular Characterization of Shiga Toxin-ProducingEscherichia coliIsolated from Ruminant and Donkey Raw Milk Samples and Traditional Dairy Products in Iran

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Hassan Momtaz ◽  
Rahil Farzan ◽  
Ebrahim Rahimi ◽  
Farhad Safarpoor Dehkordi ◽  
Negar Souod
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Dairy Products ◽  
Antibiotic Resistance Genes ◽  
Culture Method ◽  
Raw Milk ◽  
Antibiotics Resistance ◽  
E Coli ◽  
Pathogenic Genes

The aims of the current study were to detect the virulence factors and antibiotic resistance of Shiga toxin-producingE. coli, in animal milk and dairy products in Iran. AfterE. colidentification with culture method, PCR assay were developed for detection of pathogenic genes, serotypes and antibiotic resistance genes ofE. coli. Results showed that out of 719 samples, 102 (14.18%) were confirmed to be positive forE. coliand out of 102 positive samples, 17.64% were O26 and 13.72% were O157 and 1.96% were O91 and 1.96% were O145 serotypes. Totally, the prevalence ofstx1 andpapAgenes were the highest while the prevalence ofsfaSandfyuAwere the lowest in the positive samples. PCR results showed thattetA, tetBwere the highest (64.70%) andaac(3)-IVwere the lowest (27.45%) antibiotic resistant genes inE. colipositive samples. Our study indicated that the isolatedE. colitrains in these regions had a highest antibiotic resistance to tetracycline (58.82%) and the lowest to nitrofurantoin (3.92%).tetAgene andE. coliO157 serotype had highest andaac(3)-IVgene, andE. coliO145 serotype had a lowest frequency rates of antibiotics resistance genes, in the region.

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