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

Author(s):  
Farzad Esavand Heydari ◽  
Mojtaba Bonyadian ◽  
Hamdallah Moshtaghi ◽  
Masoud Sami

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.

2015 ◽  
Vol 9 (05) ◽  
pp. 496-504 ◽  
Author(s):  
Divya Sukumaran ◽  
Abdulla A Mohamed Hatha

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.


2019 ◽  
Vol 12 (11) ◽  
pp. 1840-1848 ◽  
Author(s):  
Nacima Meguenni ◽  
Nathalie Chanteloup ◽  
Angelina Tourtereau ◽  
Chafika Ali Ahmed ◽  
Saliha Bounar-Kechih ◽  
...  

Background and Aim: Avian pathogenic Escherichia coli cause extensive mortality in poultry flocks, leading to extensive economic losses. To date, in Algeria, little information has been available on virulence potential and antibiotics resistance of avian E. coli isolates. Therefore, the aim of this study was the characterization of virulence genes and antibiotic resistance profile of Algerian E. coli strains isolated from diseased broilers. Materials and Methods: In this study, 43 avian E. coli strains isolated from chicken colibacillosis lesions at different years were analyzed to determine their contents in 10 virulence factors by polymerase chain reaction, antimicrobial susceptibility to 22 antibiotics belonging to six different chemical classes and genomic diversity by pulsed-field gel electrophoresis (PFGE). Results: Mainly E. coli isolates (58.1%) carried two at six virulence genes and the most frequent virulence gene association detected were ompT (protectin), hlyF (hemolysin) with 55.8% (p<0.001), and iroN, sitA (iron acquisition/uptake systems), and iss (protectin) with 41.8% (p<0.001). Some strains were diagnosed as virulent according to their virulence gene profile. Indeed, 23.25% of the isolates harbored iroN, ompT, hlyF, iss, and sitA combination, 14% ompT, hlyF, and frzorf4 (sugar metabolism), and 11,6% iroN, hlyF, ompT, iss, iutA (iron acquisition/uptake systems), and frzorf4. The chicken embryo lethality assay performed on five isolates confirmed the potential virulence of these strains. All isolates submitted to PFGE analysis yielded different genetic profiles, which revealed their diversity. Overall, 97.2% of the isolates were resistant to at least one antibiotic and 53.5% demonstrated multi-antimicrobial resistance to three different antimicrobial classes. The highest resistance levels were against nalidixic acid (83.4%), amoxicillin and ampicillin (83.3%), ticarcillin (80.5%), pipemidic acid (75%), and triméthoprim-sulfamethoxazole (66.6%). For beta-lactam class, the main phenotype observed belonged to broad-spectrum beta-lactamases. However, extended-spectrum beta-lactamase associated with three at six virulence factors was also detected in 13 isolates. Two of them were attested virulent as demonstrated in the embryo lethality test which constitutes a real public threat. Conclusion: It would be imperative in avian production to discourage misuse while maintaining constant vigilance guidelines and regulations, to limit and rationalize antimicrobial use.


2021 ◽  
Vol 11 (3) ◽  
pp. 402-415
Author(s):  
Loubna Ghallache ◽  
Abdellah Mohamed-Cherif ◽  
Bernard China ◽  
Faiza Mebkhout ◽  
Nesrine Boilattabi ◽  
...  

Mastitis in cows is a major problem in dairy farms leading to a decrease in the quantity and quality of milk. The aim of the present study was to examine the association between the presence of Escherichia coli (E. coli) in milk and the subclinical mastitis, and to characterize the antibiotic resistance profiles of the isolated E. coli. In the current study, a total of 360 cow raw milk samples from three dairy farms of the region of Algiers were analyzed. The analysis period lasted from Spring 2017 to Winter 2019. The California Mastitis Test (CMT) was applied to detect subclinical mastitis. The E. coli strains were isolated from milk using conventional bacteriological methods. The antibiotic resistance profile of the isolated E. coli strains to 12 different antibiotics was tested using the disk diffusion method. On β-lactamase-producing strains, a double diffusion test was applied to identify the Extended-spectrum β-lactamase (ESBL) phenotype. Finally, the ctXx-M genes were amplified by PCR. Two-thirds (66.4%) of the milk samples were positive for the CMT test. A total of 97 E. coli strains were isolated from the milk samples, their resistance to antibiotics was tested, and 3.1% of the strains were resistant to trimethoprim-sulfamethoxazole, 6.2% to chloramphenicol, 12.3% to gentamicin, 13.4% to colistin, 23.3% to amoxicillin/clavulanate, 31.9% to kanamycin, 39.2% to enrofloxacin, 51.5% to cefotaxime, 52% to tetracycline, 57.7% to ampicillin, 74.3% to nalidixic acid, and 75.3% to amoxicillin. Furthermore, most of the E. coli strains (92.8%) were resistant to more than one antibiotic with a Multiple Antibiotic Resistance index ranging from 0 to 0.8. The 50 strains resistant to cefotaxime were analyzed for an ESBL phenotype. 39 of them (78%) were positive to the double-disk synergy test. Among the 39 ESBL positive strains, 27 (69.2%) were confirmed for the presence of a CTX-M gene by PCR. The present study showed that multiple drug-resistant E. coli, including ESBL-carriers, were frequently isolated from the milk of dairy cows in Algeria. The results underlined that the use of antibiotics on farms must be reasoned to avoid the spread of resistant strains in animals and human populations.


2017 ◽  
Vol 80 (11) ◽  
pp. 1877-1881 ◽  
Author(s):  
Leila Ben Said ◽  
Mouna Hamdaoui ◽  
Ahlem Jouini ◽  
Abdellatif Boudabous ◽  
Karim Ben Slama ◽  
...  

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hassan Momtaz ◽  
Farhad Safarpoor Dehkordi ◽  
Taghi Taktaz ◽  
Amir Rezvani ◽  
Sajad Yarali

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.


2020 ◽  
Vol 13 (8) ◽  
pp. 1588-1593
Author(s):  
Zuhair Bani Ismail ◽  
Sameeh M. Abutarbush

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.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 396 ◽  
Author(s):  
Michaela Sannettha van den Honert ◽  
Pieter Andries Gouws ◽  
Louwrens Christiaan Hoffman

Studies have shown that antibiotic resistance among wild animals is becoming a public health concern, owing to increased contact and co-habitation with domestic animals that, in turn, results in increased human contact, indirectly and directly. This type of farming practice intensifies the likelihood of antibiotic resistant traits in microorganisms transferring between ecosystems which are linked via various transfer vectors, such as rivers and birds. This study aimed to determine whether the practice of wildlife supplementary feeding could have an influence on the antibiotic resistance of the bacteria harboured by the supplementary fed wildlife, and thus play a potential role in the dissemination of antibiotic resistance throughout nature. Escherichia coli and Enterococcus were isolated from the faeces of various wildlife species from seven different farms across South Africa. The Kirby-Bauer disk diffusion method was used according to the Clinical and Laboratory Standards Institute 2018 guidelines. The E. coli (F: 57%; N = 75% susceptible) and Enterococcus (F: 67%; N = 78% susceptible) isolates from the supplementary fed (F) wildlife were in general, found to be more frequently resistant to the selection of antibiotics than from those which were not supplementary fed (N), particularly towards tetracycline (E. coli F: 56%; N: 71%/Enterococcus F: 53%; N: 89% susceptible), ampicillin (F: 82%; N = 95% susceptible) and sulphafurazole (F: 68%; N = 98% susceptible). Interestingly, high resistance towards streptomycin was observed in the bacteria from both the supplementary fed (7% susceptible) and non-supplementary fed (6% susceptible) wildlife isolates. No resistance was found towards chloramphenicol and ceftazidime.


Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 587
Author(s):  
Momna Rubab ◽  
Deog-Hwan Oh

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.


2021 ◽  
Vol 10 (1) ◽  
pp. 51-54

Sorbitol non-fermenting Shiga toxin producing Escherichia coli (SNF-STEC) is considered as a significant emerging pathogen. Though, cattle and buffaloes are the chief reservoir, species like goat, sheep, deer and other ruminants can also harbor this pathogen. Therefore, this pathogen can easily be transmitted to human and other animals through food chain and their environment. The present study, aimed to ascertain the antibiotic resistance profile of SNF-STEC isolates from buffaloes as well as to detect the resistance genes. A total of 33 sorbitol non-fermenting (SNF) E. coli isolates were tested against ten commonly used antibiotics both in human and veterinary medicine. Results revealed that 78.8% isolates were resistant to sulfamethoxazole-trimethoprim and nalidixic acid whereas 60.6% to tetracycline and 48.5% to doxycycline. The majority of the isolates were found sensitive to both gentamycin and ciprofloxacin (90%) followed by erythromycin (66.7%) and ceftriaxone (51.5%). Of 33 SNF E. coli, 12 were STEC harboring both stx1 and stx2 gene that dictated 66.7% isolates were found resistant to sulfamethoxazole-trimethoprim and nalidixic acid followed by ampicillin (58.3%) and tetracycline (58.3%). blaTEM was detected in 66.7% ampicillin resistant isolates and sul2 was exposed in 34.6% sulfamethoxazole-trimethoprim resistant isolates. sul1 gene was negative for the sulfamethoxazole-trimethoprim resistant isolates.


2017 ◽  
Vol 11 (01) ◽  
pp. 51-57 ◽  
Author(s):  
Yandag Munkhdelger ◽  
Nyamaa Gunregjav ◽  
Altantsetseg Dorjpurev ◽  
Nishi Juniichiro ◽  
Jav Sarantuya

Introduction: The severity of urinary tract infection (UTI) produced by uropathogenic Escherichia coli (UPEC) is due to the expression of a wide spectrum of virulence genes. E. coli strains were divided into four phylogenetic groups (A, B1, B2 and D) based on their virulence genes. The present study aimed to assess the relationship between virulence genes, phylogenetic groups, and antibiotic resistance of UPEC. Methodology: A total of 148 E. coli were tested for antimicrobial resistance against 10 drugs using the disk diffusion method. The isolates were screened by polymerase chain reaction (PCR) for detection of virulence genes and categorized into the four major phylogenetic groups. Results: Phylogenetic group B2 was predominant (33.8%), followed by D (28.4%), A (19.6), and B1 (18.2%). A higher prevalence of fimH (89.9%), fyuA (70.3%), traT (66.2%), iutA (62.2%), kpsMTII (58.8%), and aer (56.1%) genes were found in UPEC, indicating a putative role of adhesins, iron acquisition systems, and protectins that are main cause of UTIs. The most common antibiotic resistance was to cephalotin (85.1%), ampicillin (78.4%) and the least to nitrofurantoin (5.4%) and imipenem (2%). In total, 93.9% of isolates were multidrug resistant (MDR). Conclusions: This study showed that group B2 and D were the predominant phylogenetic groups and virulence-associated genes were mostly distributed in these groups. The virulence genes encoding components of adhesins, iron acquisition systems, and protectins were highly prevalent among antibiotic-resistant UPEC. Although the majority of strains are MDR, nitrofurantoin is the drug of choice for treatment of UTI patients in Ulaanbaatar.


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