Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness

نویسندگان

  • Maziar Jajarmi
  • Mahdi Askari Badouei
  • Abbas Ali Imani Fooladi
  • Reza Ghanbarpour
  • Ali Ahmadi
چکیده

BACKGROUND All over the world, Shiga toxin-producing Escherichia coli (STEC) are considered as important zoonotic pathogens. Eight serogroups have the greatest role in the outbreaks and diseases caused by STEC which include O26, O45, O103, O111, O113, O121, O145 and O157. Ruminants, especially cattle are the main reservoirs but the role of small ruminants in the epidemiology of human infections has not been thoroughly assessed in many countries. The objective of this research was to investigate the pathogenic potential of the STEC strains isolated from slaughtered goats. In this study, a total of 57 STEC strains were recovered from 450 goats and characterized by subtyping of stx genes, O-serogrouping, phylo-typing and DNA fingerprinting. RESULTS Amongst 57 STEC strains isolated from goats, the prevalence of stx1 was significantly more than stx2 (98.2% vs. 24.5%; P ≤ 0.05), and 22.8% of strains harbored both stx1 and stx2 genes. Three (5.2%) isolates were characterized as EHEC, which carried both eae and stx genes. A total of five stx-subtypes were recognized namely: stx1c (94.7%), stx1a (53.7%), stx2d (21%), stx2c (17.5%), and stx2a (15.7%). In some parts of the world, these subtypes have been reported in relation with severe human infections. The stx subtypes predominantly occurred in four combinations, including stx1a/stx1c (35%), stx1c (31.5%), stx1c/stx2a/stx2c/stx2d (5.2%) and stx1c/stx2c/stx2d (%5.2%). In serogrouping, the majority of STECs from goats did not belong to the top 8 serogroups but two strains belonged to O113, which has been recognized as an important pathogenic STEC in Australia. Interestingly, none of stx + eae + isolates belonged to the tested serogroups. In phylo-typing the isolates mostly belonged to phylo-group B1 (82.4%), followed by phylo-group A (12.3%). STEC strains showed a substantial diversity in DNA fingerprinting; there were 24 unique ERIC-types (with a ≥95% similarity) among the isolates. CONCLUSIONS Despite the fact that the top 8 STEC serogroups were uncommon in caprine strains, the presence of highly pathogenic stx subtypes indicates that small ruminants and their products can be considered as an overlooked public health risk for humans, especially in developing countries which consume traditional products.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Detection of eaeA, hlyA, stx1 and stx2 genes in pathogenic Escherichia coli isolated from broilers affected with colibacillosis

Background: Foodborne outbreaks associated with shiga toxin-producing Escherichia coli (STEC) have been well documented worldwide. STECs are major causative agents of gastroenteritis in humans that may be complicated by hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS), and thrombotic thrombocytopenia purpura (TTP). OBJECTIVES: The aim of this study was to investigate the presence of vi...

متن کامل

Detection of Shiga toxin-producing Escherichia coli (STEC) in faeces of healthy calves in Mashhad, Iran

The aim of this study was to identify virulent Shiga toxin-producing Escherichia coli (STEC) strains isolated from faecal samples of 100 clinically healthy calves. In the present study, a total of 100 Escherichia coli (E. coli) isolates from clinically healthy calves belonging to 6 different farms located in Khorasan Razavi province, Iran, were examined for presence of virulence genes character...

متن کامل

Isolation, Characterization and Antibiotic Resistance of Shiga Toxin-Producing Escherichia coli in Hamburger and Evolution of Virulence Genes stx1, stx2, eaeA and hly by Multiplex PCR

Background & Objectives: Shiga toxin-producing Escherichia coli (STEC) O157:H7 have emerged as pathogens that can cause food-borne infections and severe and potentially fatal illnesses in humans. E.coli O157:H7 colonizes the digestive tract of cattle and is transmitted to humans by food and water. The objectives of this study were to characterize the prevalence of E.coli O157:H7 isolates in ham...

متن کامل

Detection of verotoxin (Shiga-like toxin)-producing and eae harboring Escherichia coli in some wild captive and domestic Equidae and Canidae

The aim of this study was to investigate the prevalence of STEC and EPEC strains and E. coli O157 serogroup in some Equidae and Canidae. The fecal samples of 79 animals from 6 different species were evaluated for presence of these strains. All the Isolates were tested for virulence genes using multiplex-PCR. Non-sorbitol fermenting (NSF) Escherichia coli isolates and positive strains for virule...

متن کامل

Distribution of Shiga toxin genes subtypes in B1 phylotypes of Escherichia coli isolated from calves suffering from diarrhea in Tehran suburb using DNA oligonucleotide arrays

BACKGROUND AND OBJECTIVES Shiga toxin-producing Escherichia coli (STEC) have emerged as human pathogens and contamination via animal origin has been a major public health concern. We compared the distribution of phylogenetic groups and prevalence of stx gene variants among the pathogenic strains of Escherichia coli isolated from feces of diarrheatic calves in Tehran suburb farms. MATERIALS AN...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره 14  شماره 

صفحات  -

تاریخ انتشار 2018