scholarly journals Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

2014 ◽  
Vol 8 (07) ◽  
pp. 818-822 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mohammad Zibaei ◽  
Younes Soleimani-Asl

Introduction: Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. Methodology: A total of 140 Escherichia coli isolates were collected between March and October 2012 from urinary tract infections in Khorram Abad, Iran. All isolates were tested for quinoloe resistance using the disk diffusion method. Also, all quinolone-resistant isolates were screened for the presence of the qnrA and qnrB genes by polymerase chain reaction. Minimum inhibitory concentrations (MICs) of ciprofloxacin for the qnr-positive isolates were determined. Results: One hundred sixteen (82.8%) of 140 Escherichia coli isolates were nalidixic acid-resistant; among them, 14 (12.1%) and 9 (7.8%) were qnrA and qnrB-positive, respectively. Two quinolone-resistant isolates harbored both qnrA and qnrB. Among 63 ciprofloxacin-resistant isolates, 14 (22.2%) and 9 (14.3%) were found to carry qnrA and qnrB genes, respectively. The ciprofloxacin MIC range was 0.25–512 μg/mL for 23 qnr-positive Escherichia coli isolates, 18 of which had MICs values of 4–512 μg/mL. Conclusion: Our study shows that the frequency of plasmid-mediated quinolone resistance genes among E. coli isolates in Iran is high.


2020 ◽  
Author(s):  
Kingsley Ehi Ebomah ◽  
Anthony Ifeanyi Okoh

Abstract Background Carbapenems belong to beta-lactam class of antibiotics usually considered as the last line of defense because they can be effective against severe infections caused by prevalent multidrug-resistant (MDR) pathogens. However, carbapenems can be deactivated by bacteria that produce carbapenemase (beta-lactamase). This study was conducted to screen for carbapenem-resistance genes (CRGs) harbored by pathogenic strains of Escherichia coli recovered from different environmental samples. We also assessed the genetic relatedness among selected E. coli pathotypes using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR).Method: Molecular identification and characterization of the presumptive isolates were performed using PCR and isolates that exhibited antimicrobial resistance (AMR) phenotypically were further screened for some relevant CRGs (blaNDM−1, blaKPC and blaOXA−48−like). Furthermore, ERIC-PCR was used to determine the similarity and diversity of 31 E. coli strains which were randomly selected from the different sources analyzed in this study.Result Our findings revealed a total of 238 presumptive E. coli isolates, out of which 192 were confirmed positive for uidA gene. Further screening revealed 77 (40%) isolates belong to six key E. coli pathotypes and 70 of them exhibited phenotypic AMR. Additionally, twenty-nine (41%) of the 70 MDR pathogenic E. coli strains harbored CRGs; with 24 strains harboring blaNDM−1, 8 harboring blaKPC and 2 harboring blaOXA−48−like genes.Conclusion Findings also suggest that the selected E. coli pathotypes belonged to different genomic clusters, while the cluster analysis showed a possible genetic diversity among aquatic and farm isolates. Proper treatment of final effluents before discharge as well as the development of more effective strategies to control and manage the use of antimicrobial agents were strongly recommended.


2020 ◽  
Vol 22 (1) ◽  
pp. 46-52
Author(s):  
Farshad Kakian ◽  
Kourosh Naderi ◽  
Mohamad Hosaein Rezaei ◽  
Majid Validi ◽  
Behnam Zamanzad ◽  
...  

Background and aims:: Among urine pathogens, Escherichia coli (E. coli) causes 80% of urinary tract infections (UTIs). Due to the destructive nature of penicillins, cephalosporins and carbapenems (except for monobactam such as aztreonam) and carbapenemase enzymes have created many problems for treating infectious diseases. Therefore, this study aimed to investigate the phenotypic and molecular characterization of metallo-beta-lactamase (MBL) genes produced by E. coli isolates in an educational hospital during 2016- 2017. Methods: This cross-sectional study investigated 80 UTI samples affected by E. coli. In addition, antibiotic susceptibility was evaluated by disk diffusion and E-test methods for two antibiotics of meropenem and imipenem. Phenotypic tests containing modified Hodge test, ethylenediaminetetraacetic acid (EDTA) disk synergy test, and AmpC Disk were performed to identify MBL enzyme-producing strains. Finally, the frequency of Verona integron-encoded metallo-β-lactamase (VIM) and imipenemase (IMP) genes was determined by polymerase chain reaction (PCR). Results: Among 80 E. coli samples, 21 (26.25%) isolates were resistant to meropenem and imipenem as detected by the disk-diffusion method and E-test. Further, phenotypic tests including modified Hodge test, EDS test, and AmpC disk test showed the positivity of 15 (18.75%), 15 (18.75%), and 8 (10%) isolates, respectively (P < 0.001). Eventually, polymerase chain reaction (PCR) test results for the VIM gene showed 19 (23.75%) positive isolates of E. coli, but the IMP gene was observed in none of the isolates (P<0.001). Conclusion: In general, the emergence of E. coli producing MBL enzymes is a serious threat among clinical infections. The findings of this study indicated the presence of E. coli producing MBL. These enzymes can degrade carbapenems antibiotics, the last class current treatment of multiple drug-resistance infections.


2001 ◽  
Vol 13 (4) ◽  
pp. 308-311 ◽  
Author(s):  
Jacek Osek

A multiplex polymerase chain reaction (PCR) system was developed for identification of enterotoxigenic Escherichia coli (ETEC) strains and to differentiate them from other gram negative enteric bacteria. This test simultaneously amplifies heat-labile (LTI) and heat-stable (STI and STII) toxin sequences and the E. coli-specific universal stress protein ( uspA). The specificity of the method was validated by single PCR tests performed with the reference E. coli and non- E. coli strains and with bacteria isolated from pig feces. The multiplex PCR allowed the rapid and specific identification of enterotoxin-positive E. coli and may be used as a method for direct determination of ETEC and to differentiate them from other E. coli and gram-negative enteric isolates.


2019 ◽  
Vol 40 (1) ◽  
pp. 163 ◽  
Author(s):  
Leandro Parussolo ◽  
Ricardo Antônio Pilegi Sfaciotte ◽  
Karine Andrezza Dalmina ◽  
Fernanda Danielle Melo ◽  
Ubirajara Maciel Costa ◽  
...  

The serrano artisanal cheese is a typical product from South region of Brazil, which is produced by skilled cheesemakers using raw milk. The contamination of this food by Escherichia coli has a great impact on public health, since it could threat the consumers’ health. The study evaluated the presence of virulence genes, antimicrobial susceptibility profiles and bofilm-production ability of Escherichia coli isolates obtained from raw milk and artisanal cheese produced in Southern Brazil. A total of 117 isolates of E. coli were characterized by multiplex PCR to detect the following virulence genes: eae for enteropatogenic E. coli (EPEC), lt and st for enterotoxigenic E. coli (ETEC), stx for shiga toxin-producing E. coli (STEC), stx and eae for enterohemorrhagic E. coli (EHEC), ipaH for enteroinvasive E. coli (EIEC) and aggR for enteroaggregative E. coli (EAEC). In addition, antimicrobial susceptibility profile to 22 antimicrobial agents was also performed by disk diffusion method, and we searched for extended-spectrum beta-lactamases (ESBL) and/or carbapenemase- producing isolates. Isolates that were positive for ESBL and carbapenemase were further investigated for the presence of the genes: blaTEM, blaSHV, blaOXA, blaCTX-M, for ESBL and blaOXA-48 for carbapenemase. Further, isolates had their ability to form biofilms investigated by the red Congo agar method. Virulence genes of E. coli were identified in 21.37% of the tested isolates, which were classified as EPEC (the most prevalent pathotype) and ETEC or EAEC. Ten (8.55%) of the total studied E. coli isolates revealed a multidrug-resistant profile, since they were resistant to three or more antimicrobial classes; whereas four isolates (3.42%) were classified as ESBL-producers and showed the presence of blaTEM gene. None of the isolates exhibited carbapenemase activity nor did they carry carbapenemase genes. From the total of E. coli isolates, 79 (67.52%) were considered potential biofilm producers. These results address a serious public health issue, since artisanal cheeses pose a risk to consumers’ health, since may be sources of dissemination of diarrheogenic E. coli, that can cause from subclinical to severe and fatal infections in children and adults, and also emphasize the need to improve adaptations/adjustments in the manufacturing processes of these products.


2002 ◽  
Vol 65 (1) ◽  
pp. 5-11 ◽  
Author(s):  
TAKAHISA MIYAMOTO ◽  
NATSUKO ICHIOKA ◽  
CHIE SASAKI ◽  
HIROSHI KOBAYASHI ◽  
KEN-ICHI HONJOH ◽  
...  

The DNA band patterns generated by polymerase chain reaction (PCR) using the du2 primer and template DNAs from various strains of Escherichia coli and non–E. coli bacteria were compared. Among three to five prominent bands produced, the three bands at about 1.8, 2.7, and 5.0 kb were detected in all of the E. coli O157 strains tested. Some nonpathogenic E. coli and all pathogenic E. coli except E. coli O157 showed bands at 1.8 and 5.0 kb. It seems that the band at 2.7 kb is specific to E. coli O157. Sequence analysis of the 2.7-kb PCR product revealed the presence of a DNA sequence specific to E. coli O157:H− and E. coli O157:H7. Since the DNA sequence from base 15 to base 1008 of the PCR product seems to be specific to E. coli O157, a PCR assay was carried out with various bacterial genomic DNAs and O157-FHC1 and O157-FHC2 primers that amplified the region between base 23 and base 994 of the 2.7-kb PCR product. A single band at 970 bp was clearly detected in all of the strains of E. coli O157:H− and E. coli O157:H7 tested. However, no band was amplified from template DNAs from other bacteria, including both nonpathogenic and pathogenic E. coli except E. coli O157. All raw meats inoculated with E. coli O157:H7 at 3 × 100 to 3.5 × 102 CFU/25 g were positive both for our PCR assay after cultivation in mEC-N broth at 42°C for 18 h and for the conventional cultural method.


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.


Author(s):  
Hesam Alizade ◽  
Hamid Sharifi ◽  
Zahedeh Naderi ◽  
Reza Ghanbarpour ◽  
Mehdi Bamorovat ◽  
...  

This study was conducted on patients with thalassemia and HIV-infected patients to determine the frequency of diarrheagenic Escherichia coli in Kerman, Iran. We analyzed 68 and 49 E coli isolates isolated from healthy fecal samples of patients with thalassemia and HIV-infected patients, respectively. The E coli isolates were studied using a multiplex polymerase chain reaction to identify the enterotoxigenic E coli (ETEC), enterohemorrhagic E coli (EHEC), and enteropathogenic E coli (EPEC) groups. Statistical analysis was carried out to determine the correlation of diarrheagenic E coli between HIV-infected patients and patients with thalassemia using Stata 11.2 software. The frequency of having at least 1 diarrheagenic E coli was more common in patients with thalassemia (67.64%) than in HIV-infected patients (57.14%; P = .25), including ETEC (67.64% versus 57.14%), EHEC (33.82% versus 26.53%), and EPEC (19.11% versus 16.32%). The results of this study indicate that ETEC, EHEC, and EPEC pathotypes are widespread among diarrheagenic E coli isolates in patients with thalassemia and HIV-infected patients.


2016 ◽  
Vol 19 (3) ◽  
pp. 619-625 ◽  
Author(s):  
C.H. Dai ◽  
L.N. Gan ◽  
W.U. Qin ◽  
C. Zi ◽  
G.Q. Zhu ◽  
...  

AbstractAn efficient and accurate method to testEscherichia coli(E. coli) adhesion to intestinal epithelial cells will contribute to the study of bacterial pathogenesis and the function of genes that encode receptors related to adhesion. This study used the quantitative real-time polymerase chain reaction (qPCR) method. qPCR primers were designed from thePILINgene ofE. coliF18ab, F18ac, and K88ac, and the pig β-ACTINgene. Total deoxyribonucleic acid (DNA) fromE. coliand intestinal epithelial cells (IPEC-J2 cells) were used as templates for qPCR. The 2−ΔΔCtformula was used to calculate the relative number of bacteria in cultures of different areas. We found that the relative numbers of F18ab, F18ac, and K88ac that adhered to IPEC-J2 cells did not differ significantly in 6-, 12-, and 24-well culture plates. This finding indicated that there was no relationship between the relative adhesion number ofE. coliand the area of cells, so the method of qPCR could accurately test the relative number ofE. coli. This study provided a convenient and reliable testing method for experiments involvingE. coliadhesion, and also provided innovative ideas for similar detection methods.


Author(s):  
Moses Oghenaigah Eghieye ◽  
Istifanus Haruna Nkene ◽  
Rejoice Helma Abimiku ◽  
Yakubu Boyi Ngwai ◽  
Ibrahim Yahaya ◽  
...  

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) is common worldwide; and its successful treatment using antibiotics is limited by acquisition of resistance by the bacteria. This study investigated the occurrence of plasmid-mediated quinolone resistance (PMQR) genes in ciprofloxacin-resistant E. coli from urine of patients with suspected cases of UTIs attending Garki Hospital Abuja (GHA), Nigeria. A total of 8 confirmed ciprofloxacin-resistant E. coli was screened for carriage of PMQR genes using polymerase chain reaction (PCR) method. The occurrences of the PMQR genes detected were in the order: aac-(6′)-Ib-cr (87.5%) > qnrB (50.0%) > qnrS (37.5%) > oqxAB (12.5%) > qnrA(0.0%). qnrB and qnrS did not exist alone, but in combination with other genes; aac-(6′)-Ib-crexisted both alone and in combination with others; the most prevalent patterns of existence were aac-(6′)-Ib-cr alone and aac-(6′)-Ib-cr + qnrB + qnrS at 25.0% each. This study has shown that the ciprofloxacin-resistant E. coli harbored aac-(6′)-Ib-cr, qnrB, qnrS and oqxAB PMQR genes, with aac-(6′)-Ib-cr being the most prevalent. The genes were present either alone or in combination with one another. This has implication for the clinical application of fluoroquinolones to treat UTI in the study location and environs. 


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