Prevalence of Shiga Toxin-Producing and Enteropathogenic Escherichia coli in Wild and Pet Birds in Iran

ABStRACt The aim of this study was to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains and to identify the stx gene types in wild captive and companion birds. In total,657 E. coli isolates from 219 birds belonging to 38 different species were investigated for the presence of STEC and EPEC strains. It was shown that five birds (2.28%) carried strains positive for one or more of the virulence factors investigated. The results indicated that 1.8% (n=4) and 0.45% (n=1) of the birds carried STEC and EPEC strains, respectively. All STEC strains harbored the stx2f and eae genes and this finding reveals the role of other birds, in addition to pigeons, as reservoirs of STEC. The only EPEC strain in this study was isolated from a Myna. Based on our knowledge, this is the first report of Stx2f-producing STEC in Geese, Duck and Lesser kestrel. In conclusion, the results indicate a low frequency of STEC carriage in wild and companion birds, and point out the need of additionally screening for the presence of stx2f in all the eae-harboring strains from birds

Whole-Genome Characterization and Strain Comparison of VT2f-Producing Escherichia coli Causing Hemolytic Uremic Syndrome.

Verotoxigenic Escherichia coli infections in humans cause disease ranging from uncomplicated intestinal illnesses to bloody diarrhea and systemic sequelae, such as hemolytic uremic syndrome (HUS). Previous research indicated that pigeons may be a reservoir for a population of verotoxigenic E. coli producing the VT2f variant. We used whole-genome sequencing to characterize a set of VT2f-producing E. coli strains from human patients with diarrhea or HUS and from healthy pigeons. We describe a phage conveying the vtx2f genes and provide evidence that the strains causing milder diarrheal disease may be transmitted to humans from pigeons. The strains causing HUS could derive from VT2f phage acquisition by E. coli strains with a virulence genes asset resembling that of typical HUS-associated verotoxigenic E. coli

Fenotipsko i genotipsko istraživanje otpornosti na antimikrobne lijekove i proizvodnja beta-laktamaze proširenog spektra kod bakterije Escherichia coli izolirane iz krava s mastitisom

Escherichia coli has been one of the most highlighted pathogens isolated from clinical cases of mastitis. Unfortunately, the deficiency of appropriate antimicrobial stewardship and overuse of antimicrobial agents have increased antimicrobial resistance in animal isolates. The current study aimed to demonstrate the prevalence of extended-spectrum beta-lactamase (ESBL) production, resistance genes, and multi drug resistant (MDR) among E. coli isolates from cases of clinical mastitis. For this purpose, 40 E. coli isolates were collected from clinical mastitis milk samples from five farms in Mashhad, Iran. The antimicrobial susceptibility testing (AST) was applied to 15 antimicrobial agents of veterinary and human medicine interest. Also, ESBL production was evaluated using a doubledisc synergy test (DDST). The distribution of 20 resistance genes was sought among E. coli isolates by six multiplexPCR and three uniplex-PCR assays. The highest sensitivity was identified against imipenem and amikacin (100%). On the other hand, the highest resistance was observed for tetracycline and trimethoprim-sulfamethoxazole (70% - 72.5%), respectively. According to the AST and DDST tests, one isolate was confirmed as ESBL-producing and MDR. In addition, the most frequent resistance genes were blaTEM and AmpC (100% each). The qnrA encoding resistance to quinolones was similarly prevalent and detected in 50% of the isolates. In conclusion, at least three resistant genes were detected in 28 isolates (70%), but the majority of isolates were sensitive against most of the tested antibiotics. This fact might relate to the low expression of these genes within the isolates. The horizontal gene transfer of the present genes may confer resistance to other related bacterial species in humans or domestic animals.Escherichia coli jedan je od najistaknutijih patogena izoliranih kod kliničkih slučajeva mastitisa. Nažalost, izostanak odgovarajućeg upravljanja antimikrobnim lijekovima i njihova prekomjerna upotreba povećali su otpornost varijanti izoliranih iz životinja prema tim lijekovima. Cilj je ovog istraživanja bio prikazati prevalenciju proizvodnje beta-laktamaze proširenog spektra (ESBL), gensku rezistenciju i višestruku rezistentnciju na lijekove (MDR) među izolatima E. coli dobivenim od krava s kliničkim mastitisom. U tu je svrhu prikupljeno 40 izolata E. coli iz uzoraka mlijeka krava s pet farmi u Mashhadu u Iranu. Istraživanje osjetljivosti na antimikrobne lijekove (AST) otkrilo je 15 antimikrobnih tvari važnih za veterinarsku i humanu medicinu. Proizvodnja ESBL-a pritom je procijenjena upotrebom testa sinergije s dvostrukim diskom (engl. double-disc synergy test, DDST). Raspodjela 20 gena rezistancije među izolatima E. coli pretražena je putem šest multiplex-PCR testa i tri uniplex-PCR testa. Najveća je osjetljivost pronađena na imipenem i amikacin (100%), dok je najveća rezistencija uočena kod tetraciklina (70%) i trimetoprim-sulfametoksazola (72,5%). Prema testovima AST i DDST, jedan je izolat potvrđen kao proizvod ESBL-a i MDR. Najveća (100 %) je stopa gena rezistencije uočena za gene blaTEM i AmpC. Gen qnrA koji kodira rezistenciju na kinolone imao je također visoku prevalenciju i otkriven je u 50% izolata. Zaključeno je da su najmanje tri gena rezistencije otkrivena u 28 izolata (70%). Većina se izolata pokazala osjetljivima na antibiotike testirane ovim istraživanjem. Ta spoznaja može biti povezana s niskom ekspresijom gena rezistencije u izolatima. Horizontalni prijenos ovih gena može uzrokovati rezistenciju prema drugim srodnim bakterijskim vrstama u ljudi i kod domaćih životinja

Antimicrobial resistance patterns and phylogenetic analysis of shiga toxin-producing escherichia coli strains from goats using both clermont phylogenetic schemes

Foodborne transmission of Shiga toxin-producing Escherichia coli (STEC) poses a threat to public health. The Clermont typing schemes (previous and revised) have been used widely to phylotype E. coli. The present study was conducted to compare the relationship of the Clermont phylogenetic schemes in STEC strains isolated from goats and antibiotic resistance patterns in the southeast of Iran. Overall 52 strains carrying the stx gene were used for subsequent analysis. All strains were deter-mined by analysing the genomic DNA with a PCR-based method using the two Clermont et al. (2000, 2013) schemes. Extended spectrum beta-lactamase (ESBL) producing strains were confirmed by the double disk-diffusion method. STEC strains were also tested for susceptibility to 20 antimicrobials agents. In the original Clermont method, the prevalent phylogroups were B1 (69.2) and A (28.8). The significant phylogenetic groups of strains according to the revised Clermont method were B1 (82.7), A (13.5) and unknown (3.8). However, STEC strains underwent changes as noted from A to B1 (17.3), B1 to unknown (3.8), B1 to A (1.9) and D to B1 (1.9) groupings. Of the 52 stx-positive strains, two ESBL producing strains were detected. Susceptibility data showed that the most frequent resistance phenotype was related to cefazolin (90.4), streptomycin (88.5), ampicillin (86.5) and oxytetracycline (82.7) respectively. Although the overall frequency of the reassigned phylotypes was not significant, most changes occurred within the A phylotype. Therefore, implementation of the new method on isolates belonging to the A phylotype in the old method seems to be necessary to obtain accurate results. © 2021, Trakia University. All rights reserved

Molecular detection and occurrence of vancomycin resistance genes (van A, B, C1, C2/C3) among Enterococcus species isolated from farm ostriches

Abstract Background Evaluating the prevalence of vancomycin resistance genes (van genes) in enterococcal isolates from food‐producing animals is an important public health issue because of the possibility of resistance genes spread to human. Objectives The present study aimed to determine the occurrence of vancomycin resistance genes among Enterococcus species obtained from ostrich faecal samples. Methods One hundred and twenty‐five faecal samples of apparently healthy ostriches from five different farms were investigated. Genes encoding vancomycin resistance were studied by multiplex‐PCR, and susceptibility to six antibiotics was evaluated by disk‐diffusion method. Results In total, 107 Enterococcus spp. isolates were obtained and confirmed by biochemical and molecular tests. Enterococcus faecium was the prevailing species (56 isolates of 107; 52.3%), followed by E. hirae (24 isolates; 22.4%) and E. gallinarum (12 isolates; 11.2%). Of the 107 recovered isolates, 44% harboured at least a type of van genes. vanA, vanC2/3 and vanC1 were identified in 34 (31.7%), 13 isolates (12.1%) and 4 (3.7%) isolates respectively. Additionally, four isolates (E. gallinarum, E. rafinosus) co‐harboured the the vanA and vanC1 or vanA and vanC2/3. Enterococcus faecium and Enterococcus hirae strains with the vanA genotype were the most frequent van‐carrying enterococci from ostrich faecal samples. Among van‐carrying enterococcal isolates, 23.4% were phenotypically resistant to vancomycin. This study revealed a relatively high prevalence (44%) of van‐carrying enterococci in ostrich faecal samples. Conclusions Results of the present study suggest that ostrich faeces could be considered as a reservoir of vancomycin resistance genes, especially vanA containing enterococci that could be potentially transferred to human through the food chain

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, 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