scholarly journals Shiga Toxin-ProducingEscherichia coliIsolated from Bovine Mastitic Milk: Serogroups, Virulence Factors, and Antibiotic Resistance Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hassan Momtaz ◽  
Farhad Safarpoor Dehkordi ◽  
Taghi Taktaz ◽  
Amir Rezvani ◽  
Sajad Yarali
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Antibiotic Resistance Genes ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Mastitic Milk ◽  
Antibiotic Resistance Properties

The aim of this study was to detect the virulence factors, serogroups, and antibiotic resistance properties of Shiga toxin-producingEscherichia coli, by using 268 bovine mastitic milk samples which were diagnosed using California Mastitis Test. AfterE. coliidentification, PCR assays were developed for detection of different virulence genes, serogroups, and antibiotic resistance genes ofEscherichia coli. The antibiotic resistance pattern was studied using disk diffusion method. Out of 268 samples, 73 (27.23%) were positive forEscherichia coli, and, out of 73 positive samples, 15 (20.54%) were O26 and 11 (15.06%) were O157 so they were the highest while O111 was not detected in any sample so it was the lowest serogroup. Out of 73 STEC strains, 11 (15.06%) and 36 (49.31%) were EHEC and AEEC, respectively. All of the EHEC strains hadstx1,eaeA, andehly, virulence genes, while in AEEC strainsstx1had the highest prevalence (77.77%), followed byeaeA(55.55%). Totally,aadA1(65.95%) had the highest whileblaSHV(6.38%) had the lowest prevalence of antibiotic resistance genes. The disk diffusion method showed that the STEC strains had the highest resistance to penicillin (100%), followed by tetracycline (57.44%), while resistance to cephalothin (6.38%) was the lowest.

scholarly journals Prevalence and antibiotic resistance profile of Shiga toxin-producing Escherichia coli isolated from diarrheal samples

2020 ◽  
Author(s):  
Farzad Esavand Heydari ◽  
Mojtaba Bonyadian ◽  
Hamdallah Moshtaghi ◽  
Masoud Sami
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Enterohemorrhagic Escherichia Coli ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Resistance Profile ◽  
E Coli ◽  
Antibiotic Resistance Profile

Background and Objectives: Enterohemorrhagic Escherichia coli (EHEC) causes bloody and non-bloody diarrhea, intestinal infection and extraintestinal complications in humans. This study aimed to isolate and evaluate the prevalence of E. coli O157: H7 and other Shiga toxin-producing E. coli (STEC) and identify the virulence genes (stx1, stx2, hly and eaeA) from patients with diarrhea. Also, the antibiotic resistance profile of the isolated strains was evaluated. Materials and Methods: A total of 100 stool samples were collected from patients with acute diarrhea referring to the hospital and clinics in Isfahan County, Iran. Phenotypic tests and PCR assay were used for detection of E. coli O157: H7 and other Shiga toxin-producing E. coli. The presence of virulence genes (stx1, stx2, hly and eaeA) were identified by PCR. The antibiotic resistance profile of the isolates was determined using the agar disk diffusion method. The results were analyzed descriptively by Sigma stat version 4 software. Results: Seventy - eight out of 100 samples (78%) were contaminated with E. coli. E. coli O157 was isolated from five samples (6.4%), of which only two strains (2.56%) were identified as E. coli O157: H7. According to the results, out of two E. coli O157: H7 isolates, one (50%) isolate contained eaeA and two isolates (100%) contained Stx1, Stx2, hlyA genes. Out of three (3.84%) E. coli O157: HN, one of the isolate (33.3%) contained stx1 and, two isolates (66.7%) were positive for hlyA genes. Also, the results revealed that six strains (7.69%) were non-O157: H7 STEC, of which two isolates (33.3%) contained stx1 and four isolates (66.7%) were positive for stx2 and hlyA genes. The results of antibiogram tests revealed that all of the STEC isolates (100%) were sensitive to imipenem followed by kanamycin, gentamicin and nitrofurantoin (91%). High resistance (54.5%) to ampicillin and ciprofloxacin was observed among the STEC isolates. Conclusion: The results of the current study showed that although the prevalence of E. coli O157: H7 was low among patients with diarrhea, the other STEC strains with relative resistance to antibiotics are more prevalent.

scholarly journals Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, south India

2015 ◽  
Vol 9 (05) ◽  
pp. 496-504 ◽  
Author(s):  
Divya Sukumaran ◽  
Abdulla A Mohamed Hatha
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Virulence Factor Genes

Introduction: Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections. Methodology: Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC. Results: Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05). Conclusions: Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.

scholarly journals Prevalence of class 1 and 2 integrons among the multidrug resistant uropathogenic strains of Escherichia coli

2017 ◽  
Vol 9 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Haddadi Azam ◽  
Somayeh Mikaili Ghezeljeh ◽  
Shavandi Mahmoud
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Integrase Gene ◽  
Class 1 ◽  
Tract Infections

Abstract Background Multidrug resistance is a serious problem in the treatment of urinary tract infections. Horizontal gene transfer, directed by strong selective pressure of antibiotics, has resulted in the widespread distribution of multiple antibiotic resistance genes. The dissemination of resistance genes is enhanced when they are trapped in integrons. Objectives To determine the prevalence of integrons among multidrug resistant Escherichia coli strains collected from regional hospitals and private clinical laboratories in Alborz province. Methods The susceptibility of 111 clinical Escherichia coli isolates was tested using a Kirby–Bauer disk diffusion method for common antibiotics. Isolates were screened for the production of extended spectrum β-lactamases (ESBLs) using a double disk synergy test. The existence of integrons was confirmed by amplification of the integrase gene and their class determined via analysis of PCR products by PCR-RFLP. Results Isolates showed the highest resistance to amoxicillin. Nitrofurantoin, amikacin, and ceftizoxime were the most effective antibiotics in vitro. Eighty-eight isolates of 111 (79%) were resistant to more than three unrelated drugs. We found 30% of the multidrug resistant isolates harbor integrons. Class 1 and 2 integrons were detected in 25 and 1 isolates, respectively. ESBL screening of strains showed 45 isolates (40%) were positive; 22% of the ESBL-positive isolates carried class 1 integrons and the frequency of MDR in ESBLpositive isolates was 93%. Conclusion The existence of integrons in only 29.5% of multidrug resistant isolates showed that besides integrons, antibiotic resistance genes were probably carried on other transferable elements lacking integrons, such as transposons or plasmids.

scholarly journals Antibiotic Resistance, Phylogenetic Typing and Virulence Genes Profile Analysis of Uropathogenic Escherichia Coli Isolated From Patients in Southern Iraq

2021 ◽  
Author(s):  
Mohammed Allami ◽  
Masoumeh Bahreini ◽  
Mohammad Reza Sharifmoghadam
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Gene Diversity ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Phylogenetic Groups ◽  
Disk Diffusion Method ◽  
Tract Infections ◽  
Southern Iraq

Abstract Of the most common infectious diseases that occur mainly by uropathogenic Escherichia coli (UPEC) is urinary tract infections (UTIs). The purpose of this study was to investigate virulence factors, antibiotic resistance, and phylogenetic groups among UPEC strains isolated from patients with UTI in southern Iraq. A total of 100 UPEC isolates were collected from urine samples of UTI patients from various hospitals in southern Iraq, and confirmed by morphological and biochemical tests. Antimicrobial susceptibility testing on isolates was performed by disk diffusion method. Multiplex PCR technique was used to evaluate the phylogenetic groups and the presence of six virulence factor genes; type 1 fimbria (fimH), A-fimbrial adhesion (afa), hemolysin (hly), fimbrial adhesins P (papC), cytotoxic necrosis factor 1 (cnf1), and aerobactin (aer). The majority of isolates belonged to the phylogenetic groups of B2 (55%) and D (32%). The most prevalent virulence factors were fimH (96%), followed by aer (47%), papC (36%), cnf1 (17%), hly (15%), and afa (8%). Phenotypic testing showed that the isolates were most resistant to piperacillin, ticarcillin, amoxicillin/clavulanic acid (92%, 91%, and 88%, respectively) and most sensitive to amikacin and imipenem, respectively. The maximum antibiotic resistance and virulence factors were observed in the phylogenetic group B2. The results showed that the UPEC isolates had all six virulence factors with high frequency and the highest drug resistance. Besides, the results showed a direct relationship between virulence factors, gene diversity, phylogenetic background, and antimicrobial resistance in the UPEC isolates.

First Detection of CTX-M-1 in Extended-Spectrum β-Lactamase–Producing Escherichia coli in Seafood from Tunisia

2017 ◽  
Vol 80 (11) ◽  
pp. 1877-1881 ◽  
Author(s):  
Leila Ben Said ◽  
Mouna Hamdaoui ◽  
Ahlem Jouini ◽  
Abdellatif Boudabous ◽  
Karim Ben Slama ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Diffusion Method ◽  
Carriage Rate ◽  
Disk Diffusion Method ◽  
Class 1 Integron ◽  
E Coli ◽  
Extended Spectrum ◽  
Class 1

ABSTRACT The purpose of this study was to determine the carriage rate of Escherichia coli isolates in seafood, to analyze the phenotype and genotype of antimicrobial resistance in the recovered isolates, and to characterize extended-spectrum β-lactamase (ESBL) E. coli producers. E. coli isolates were recovered from 24 (34.3%) of the 70 seafood samples analyzed, and one isolate per sample was further characterized. Antibiotic resistance was determined by the disk diffusion method in the 24 isolates, with the following results (number of resistant isolates): tetracycline (8), streptomycin (7), ampicillin (6), trimethoprim-sulfamethoxazole (4), chloramphenicol (4), ciprofloxacin (3), cefotaxime (2), and ceftazidime (2). Six isolates showed a multiresistant phenotype (including at least three families of antibiotics). Among tetracycline-resistant E. coli isolates, tet(A) was detected in five isolates and tet(B) in two isolates. The qnr(A) or aac(6′)-1b-cr genes were detected in two ciprofloxacin-resistant E. coli isolates, and the sul2 gene in two trimethoprim-sulfamethoxazole–resistant isolates. ESBL-containing E. coli isolates, carrying the blaCTX-M-1 gene, were detected in 2 of the 70 seafood samples, obtained from gilt-head bream aquaculture. The ESBL isolates were typed phylogenetically and by multilocus sequence typing, and they were ascribed to lineage ST48/A and to the new ST3497/B1; these isolates carried the fimA, aer, and papGIII virulence genes. One of the ESBL-producing E. coli isolates carried an unusual class 1 integron (with the array dfr32-ereA-aadA1). Seafood could be a source of multiresistant E. coli isolates for the aquatic environment, and these could enter the food chain.

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 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 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 Preliminary Results on the Prevalence of Salmonella Spp. in Marine Animals Stranded in Sicilian Coasts: Antibiotic Susceptibility Profile and ARGs Detection in the Isolated Strains

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 930
Author(s):  
Delia Gambino ◽  
Sonia Sciortino ◽  
Sergio Migliore ◽  
Lucia Galuppo ◽  
Roberto Puleio ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Susceptibility ◽  
Antibiotic Resistance Genes ◽  
Diffusion Method ◽  
Salmonella Spp ◽  
Marine Animals ◽  
Disk Diffusion Method ◽  
Phenotypic Resistance ◽  
Low Prevalence

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.

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