Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness
Abstract 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, especia...
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BMC
2018-03-01
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| Series: | BMC Veterinary Research |
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| Online Access: | http://link.springer.com/article/10.1186/s12917-018-1407-2 |
| _version_ | 1819026873740427264 |
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| author | Maziar Jajarmi Mahdi Askari Badouei Abbas Ali Imani Fooladi Reza Ghanbarpour Ali Ahmadi |
| author_facet | Maziar Jajarmi Mahdi Askari Badouei Abbas Ali Imani Fooladi Reza Ghanbarpour Ali Ahmadi |
| author_sort | Maziar Jajarmi |
| collection | DOAJ |
| description | Abstract 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. |
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| language | English |
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| spelling | doaj.art-214e5f486ee04240ad93ec9d129cf1672022-12-21T19:14:29ZengBMCBMC Veterinary Research1746-61482018-03-011411810.1186/s12917-018-1407-2Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatednessMaziar Jajarmi0Mahdi Askari Badouei1Abbas Ali Imani Fooladi2Reza Ghanbarpour3Ali Ahmadi4Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical SciencesDepartment of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of MashhadApplied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical SciencesMolecular Microbiology Research Group, Shahid Bahonar University of KermanMolecular Biology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical SciencesAbstract 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.http://link.springer.com/article/10.1186/s12917-018-1407-2GoatsphylogenyserogroupShiga-toxin producing Escherichia colisubtype |
| spellingShingle | Maziar Jajarmi Mahdi Askari Badouei Abbas Ali Imani Fooladi Reza Ghanbarpour Ali Ahmadi Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness BMC Veterinary Research Goats phylogeny serogroup Shiga-toxin producing Escherichia coli subtype |
| title | Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness |
| title_full | Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness |
| title_fullStr | Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness |
| title_full_unstemmed | Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness |
| title_short | Pathogenic potential of Shiga toxin-producing Escherichia coli strains of caprine origin: virulence genes, Shiga toxin subtypes, phylogenetic background and clonal relatedness |
| title_sort | pathogenic potential of shiga toxin producing escherichia coli strains of caprine origin virulence genes shiga toxin subtypes phylogenetic background and clonal relatedness |
| topic | Goats phylogeny serogroup Shiga-toxin producing Escherichia coli subtype |
| url | http://link.springer.com/article/10.1186/s12917-018-1407-2 |
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