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.

scholarly journals Transfer of Class 1 Integron-Mediated Antibiotic Resistance Genes from Shiga Toxin-Producing Escherichia coli to a Susceptible E. coli K-12 Strain in Storm Water and Bovine Feces

2008 ◽  
Vol 74 (16) ◽  
pp. 5063-5067 ◽  
Author(s):  
Supakana Nagachinta ◽  
Jinru Chen
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Antibiotic Resistance Genes ◽  
Storm Water ◽  
Class 1 Integron ◽  
E Coli ◽  
Class 1 ◽  
K 12 ◽  
Bovine Feces

ABSTRACT Transfer of class 1 integron-mediated antibiotic resistance genes has been demonstrated under laboratory conditions. However, there is no information concerning the transfer of these genes in an agricultural environment. The present study sought to determine if integron-mediated streptomycin and sulfisoxazole resistance genes could be transferred from Shiga toxin-producing Escherichia coli (STEC) strains 6-20 (O157:H7) and 7-63 (O111:H8) to the susceptible strain E. coli K-12 MG1655 in bovine feces (pH 5.5, 6.0, or 6.5) and storm water (pH 5, 6, 7, or 8) at 4, 15, and 28°C, which are average seasonal temperatures for winter, spring-fall, and summer, respectively, in the Griffin, GA, area. The results indicated that at 28°C, the integron-mediated antibiotic resistance genes were transferred from both of the STEC donors in bovine feces. Higher conjugation efficiencies were, however, observed in the conjugation experiments involving STEC strain 6-20. In storm water, the resistance genes were transferred only from STEC strain 6-20. Greater numbers of transconjugants were recovered in the conjugation experiments performed with pH 6.5 bovine feces and with pH 7 storm water. Antibiotic susceptibility tests confirmed the transfer of integron-mediated streptomycin resistance and sulfisoxazole resistance, as well as the transfer of non-integron-mediated oxytetracycline resistance and tetracycline resistance in the transconjugant cells. These results suggest that the antibiotic resistance genes in STEC could serve as a source of antibiotic resistance genes disseminated via conjugation to susceptible cells of other E. coli strains in an agricultural environment.

scholarly journals Molecular Detection of Antibiotic Resistance Genes in Shiga toxin-producing E. coli Isolated from Different Sources

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 344
Author(s):  
Momna Rubab ◽  
Deog-Hwan Oh
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Foodborne Illnesses ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Conventional Antibiotics

Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen associated with human gastroenteritis outbreaks. Extensive use of antibiotics in agriculture selects resistant bacteria that may enter the food chain and potentially causes foodborne illnesses in humans that are less likely to respond to treatment with conventional antibiotics. Due to the importance of antibiotic resistance, this study aimed to investigate the combination of phenotypic and genotypic antibiotic resistance in STEC isolates belonging to serogroups O26, O45, O103, O104, O111, O121, O145, and O157 using disc diffusion and polymerase chain reaction (PCR), respectively. All strains were phenotypically resistant to at least one antibiotic, with 100% resistance to erythromycin, followed by gentamicin (98%), streptomycin (82%), kanamycin (76%), and ampicillin (72%). The distribution of antibiotic resistance genes (ARGs) in the STEC strains was ampC (47%), aadA1 (70%), ere(A) (88%), blaSHV (19%), blaCMY (27%), aac(3)-I (90%), and tet(A) (35%), respectively. The results suggest that most of the strains were multidrug-resistant (MDR) and the most often observed resistant pattern was of aadA1, ere(A), and aac(3)-I genes. These findings indicate the significance of monitoring the prevalence of MDR in both animals and humans around the globe. Hence, with a better understanding of antibiotic genotypes and phenotypes among the diverse STEC strains obtained, this study could guide the administration of antimicrobial drugs in STEC infections when necessary.

Integron-Mediated Antibiotic Resistance in Shiga Toxin–Producing Escherichia coli

2009 ◽  
Vol 72 (1) ◽  
pp. 21-27 ◽  
Author(s):  
SUPAKANA NAGACHINTA ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Antibiotic Resistance Genes ◽  
Conjugative Plasmid ◽  
E Coli ◽  
Class 1 Integrons ◽  
Class 1 ◽  
K 12

This study was undertaken to characterize the integrons present in a group of Shiga toxin–producing Escherichia coli (STEC) isolates and the ability of these integrons to transfer antibiotic resistance genes from STEC to E. coli K-12 MG1655. A total of 177 STEC isolates were analyzed for antibiotic susceptibility and the presence of integrons. Class 1 integrons were detected in 14 STEC isolates, and a class 2 integron was identified in 1 STEC isolate. The STEC isolates positive for class 1 integrons were resistant to streptomycin (MICs > 128 μg/ml) and sulfisoxazole (MICs > 1,024 μg/ml), and the isolate positive for the class 2 integron was resistant to streptomycin (MIC of 128 μg/ml), trimethoprim (MIC > 256 μg/ml), and streptothricin (MIC > 32 μg/ml). Results of restriction digestion and nucleotide sequencing revealed that the cassette regions of the class 1 integrons had a uniform size of 1.1 kb and contained a nucleotide sequence identical to that of aadA1. The class 2 integron cassette region was 2.0 kb and carried nucleotide sequences homologous to those of aadA1, sat1, and dfrA1. Results of the conjugation experiments revealed that horizontal transfers of conjugative plasmids are responsible for the dissemination of class 1 integron–mediated antibiotic resistance genes from STEC to E. coli K-12 MG1655. Antibiotic resistance traits not mediated by integrons, such as resistance to tetracycline and oxytetracycline, were cotransferred with the integron-mediated antibiotic resistance genes. The study suggested a possible role of integron and conjugative plasmid in dissemination of genes conferring resistance to antibiotics from pathogenic to generic E. coli cells.

scholarly journals Presence of virulence factors and antibiotic resistance among Escherichia coli strains isolated from human pit sludge

2019 ◽  
Vol 13 (03) ◽  
pp. 195-203 ◽  
Author(s):  
Zahid Hayat Mahmud ◽  
Farozaan Fatima Shirazi ◽  
Muhammad Riadul Haque Hossainey ◽  
Mohammad Imtiazul Islam ◽  
Mir Alvee Ahmed ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Antibiotic Resistance Genes ◽  
Culture Method ◽  
Diffusion Method ◽  
Specific Gene ◽  
M Gene ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Pathogenic Genes

Introduction: In Bangladesh, human sludge from dry pit latrines is commonly applied directly to agricultural lands as manure. This study was conducted to investigate the presence of antibiotic resistance, virulence factors and plasmid contents of E. coli strains isolated from sludge samples. Methodology: E. coli were isolated from human feces from closed pit latrines and identified by culture method. Antibiotic susceptibility patterns of the isolates were determined by Standard Kirby-Bauer disk diffusion method. Pathogenic genes and antibiotic resistance genes of ESBL producing isolates were determined by PCR assay. Results: Of the 34 samples tested, 76.5% contained E. coli. Of 72 E. coli isolates, 76.4% were resistant to at least one of the 12 antibiotics tested and 47.2% isolates were resistant to three or four classes of antibiotics. Around 18% isolates were extended spectrum β- lactamase producing and of them 6 were positive for blaTEM specific gene, 4 for blaCTX-M gene, 1 for blaOXA gene and 2 for both blaTEM and blaCTX-M genes. Moreover, among 72 isolates, 4.2% carried virulence genes of enterotoxigenic E. coli; two isolates were positive for st and one was positive for both st and lt genes. In addition, 59.7% of the isolates contained plasmids (range 1.4 to 140 MDa) of which 19.5% isolates contained a single plasmid and 40.2% contained multiple plasmids. Conclusions: The presence of pathogenic, drug resistant E. coli in human sludge necessitates a regular surveillance before using as a biofertilizer.

scholarly journals Distribution of Some Antibiotics Resistance Genes in Multi-drug Resistant E. coli Isolates from the Urogenitals of Women in Port Harcourt, Nigeria

2019 ◽  
pp. 1-7
Author(s):  
Josephine Anem Kpalap ◽  
Easter Godwin Nwokah ◽  
Moses Nnaemeka Alo
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Randomized Study ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Antibiotics Resistance ◽  
Multiple Drug ◽  
Drug Resistant ◽  
E Coli ◽  
Port Harcourt

Aim: The problem of antibiotics resistance has assumed a global emergency status. Whereas Multidrug Resistant (MDR) E. coli infection is common among human population in Port Harcourt metropolis of Nigeria, the genetic background of E. coli isolates in our locality is not well elucidated, hence this study. Study Design: This was a randomized study of women, with indications of Urogenital infections, attending Braithwaite Memorial Specialist Hospital (BMSH) Port Harcourt, Nigeria between July and December, 2017. Methodology: Ninety-Seven (97) samples comprising of urine, high vaginal swabs, end ocervical swabs were collected from patients to assess for the presence of some antibiotic resistance genes in multi-drug resistant E. coli. Samples were processed following standard microbiological protocols. Antimicrobial susceptibility test was performed on all E. coli isolates. Following this, all Multiple Drug Resistant E. coli were subjected to polymerase chain reaction (PCR) method for the detection of some antibiotic resistance-encoding genes- SHV, CTX-M, TEM.  Results: Seventy-three (73) isolates, including 36 E. coli, were recovered from all the clinical specimens. Twenty-four (24) E. coli isolates were found to be multi-drug resistant. Sulphydryl Variable (SHV) was the most frequent resistant gene and was detected in 15 isolates. This was followed by Cefotaximase (CTX-M) in 10 isolates and Temoniera (TEM) in 5 isolates. Some isolates haboured more than one resistance gene. About 20% of the isolates haboured SHV/CTX-M; 2.5% haboured CTX-M/TEM, while no target was detected in one isolate. Conclusion: This present study revealed that most E. coli isolates from the urogenitals of women within our locality, possess the ESBL genes which confers on them the Multidrug resistant status and this is a major challenge to maternal health.

scholarly journals Mechanisms of Resistance in Multiple-Antibiotic-Resistant Escherichia coli Strains of Human, Animal, and Food Origins

2004 ◽  
Vol 48 (10) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yolanda Sáenz ◽  
Laura Briñas ◽  
Elena Domínguez ◽  
Joaquim Ruiz ◽  
Myriam Zarazaga ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Amino Acid ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mechanisms Of Resistance ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Class 1 ◽  
Human Animal

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.

scholarly journals Antibiotic-resistant Escherichia coli and Salmonella spp. associated with dairy cattle and farm environment having public health significance

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 ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
One Health ◽  
Dairy Farm ◽  
Antibiotic Resistance Genes ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
E Coli

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.

Antibiotic susceptibility profiles and frequency of resistance genes in clinical Shiga toxin-producing Escherichia coli isolates from Michigan over a 14-year period

2021 ◽  
Author(s):  
Sanjana Mukherjee ◽  
Heather M. Blankenship ◽  
Jose A. Rodrigues ◽  
Rebekah E. Mosci ◽  
James T. Rudrik ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Antibiotic Susceptibility ◽  
Genetic Relatedness ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Mechanisms Of Resistance ◽  
Susceptibility Profiles

Background: Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that contributes to over 250,000 infections in the US each year. Because antibiotics are not recommended for STEC infections, resistance in STEC has not been widely researched despite an increased likelihood for the transfer of resistance gene from STEC to opportunistic pathogens residing within the same microbial community. Methods: Between 2001 and 2014, 969 STEC isolates were collected from Michigan patients. Serotyping and antibiotic susceptibility profiles to clinically relevant antibiotics were determined using disc diffusion, while epidemiological data was used to identify factors associated with resistance. Whole genome sequencing was used to examine genetic relatedness and identify genetic determinants and mechanisms of resistance in the non-O157 isolates. Results: Increasing frequencies of resistance to at least one antibiotic was observed over the 14 years (p=0.01). While the non-O157 serogroups were more commonly resistant than O157 (Odds Ratio: 2.4; 95% Confidence Interval:1.43-4.05), the frequency of ampicillin resistance among O157 isolates was significantly higher in Michigan compared to the national average (p=0.03). Genomic analysis of 321 non-O157 isolates uncovered 32 distinct antibiotic resistance genes (ARGs). Although mutations in genes encoding resistance to ciprofloxacin and ampicillin were detected in four isolates, most of the horizontally acquired ARGs conferred resistance to aminoglycosides, β-lactams, sulfonamides and/or tetracycline. Conclusions: This study provides insight into the mechanisms of resistance in a large collection of clinical non-O157 STEC isolates and demonstrates that antibiotic resistance among all STEC serogroups has increased over time, prompting the need for enhanced surveillance.

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