scholarly journals Distribution and Molecular Analysis of Subtilase Cytotoxin Gene (subAB) Variants in Shiga Toxin-Producing Escherichia Coli (STEC) Isolated From Different Sources in Iran

2021 ◽  
Author(s):  
Mahdi Askari Badouei ◽  
Maziar Jajarmi ◽  
Aria Narimani ◽  
Taghi Zahraei Salehi ◽  
Reza Ghanbarpour ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Small Ruminants ◽  
Source Tracking ◽  
Virulence Markers ◽  
Genes Encoding ◽  
Outbreak Investigations ◽  
Subtilase Cytotoxin ◽  
Different Sources ◽  
Chromosomal Variants ◽  
Cytotoxin Gene

Abstract Background Subtilase is a potent cytotoxin that was first described in O113:H21 strain in Australia as a plasmid- encoded cytotoxin (subAB1). Subsequently, chromosomal variants including subAB2-1, subAB2-2, and subAB2-3 were described. Results In the present study a collection of 101 archived STEC strains isolated from various sources in Iran (2009–2016) were analyzed for the detection of different genes encoding the subtilase variants, plasmidic and chromosomal virulence genes, together with the phylogroup and serogroups. Overall, 57 isolates (56.4%) carried at least one variant of subAB. Most strains from small ruminants including 93% of sheep and 96% of caprine isolates carried at least one chromosomally encoded variant (subAB-2-1 and/or subAb2-2). In contrast, 12 cattle isolates (24%) only harbored the plasmid encoded variant (subAB1). STEC strains from other sources including deer, pony and humans were positive for subAB-2-1 and/or subAb2-2. Concerning the virulence markers, some strains showed an association with hosts the bacteria were isolated from. In particular, tia was associated with sheep, goats and pony isolates and astA gene was present in deer, pony and goats and terD was only found in deer and pony isolates. Only cattle STEC carried espP and epeA, the important markers of pO113 plasmid. Some genes were widespread among strain of various sources like ehly, iha and lpfO113 and some genes were not detected such as efa1, toxB and katP. Most strains belonged to phylogenetic group B1 (89.47%), but five strains from cattle, deer, pony and a goat were assigned to A phylogroup. Most cattle strains belonged to O113, while O5 was just detected in ovine isolates, and O128 and O113 were present in caprine strains. Conclusions the present study reveals the presence of potentially pathogenic genotypes among LEE-negative isolates and some host specificity related to subtilase variants and other virulence markers that may aid in source tracking of STEC during outbreak investigations.

scholarly journals Distribution and molecular analysis of Subtilase cytotoxin gene (subAB) variants in Shiga toxin-producing Escherichia coli (STEC) isolated from different sources in Iran

2020 ◽  
Author(s):  
Mahdi Askari Badouei ◽  
Maziar Jajarmi ◽  
Aria Narimani ◽  
Taghi Zahraei Salehi ◽  
Reza Ghanbarpour ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Small Ruminants ◽  
Source Tracking ◽  
Virulence Markers ◽  
Genes Encoding ◽  
Subtilase Cytotoxin ◽  
Different Sources ◽  
Asta Gene ◽  
Chromosomal Variants ◽  
Cytotoxin Gene

Subtilase is a potent cytotoxin that was first described in O113:H21 strain in Australia as a plasmid- encoded cytotoxin (subAB1). Subsequently, chromosomal variants including subAB2-1, subAB2-2, and subAB2-3 were described. In the present study a collection of 101 STECs isolated from various sources in Iran (2009-2016) were analyzed for the detection of different genes encoding the subtilase variants, plasmidic and chromosomal virulence genes, together with the phylogroup and serogroups. Overall, 57 isolates (56.4%) carried at least one variant of subAB. Most strains from small ruminants including 93% of sheep and 96% of caprine isolates carried at least one chromosomally encoded variant (subAB-2). In contrast, 12 cattle isolates (24%) only harbored the plasmid encoded variant (subAB1). STEC strains from other sources including deer, pony and humans were positive for subAB-2-1 and/or subAb2-2. Concerning the virulence markers, some strains showed an association with hosts the bacteria were isolated from. In particular, tia was associated with sheep, goats and pony isolates and astA gene was present in deer, pony and goats and terD was only found in deer and pony isolates. Only cattle STEC carried espP and epeA, the important markers of pO113 plasmid. Some genes were widespread among strain of various sources like ehly, iha and lpfO113 and some genes were not detected such as efa1, toxB and katP. Most strains belonged to phylogenetic group B1 (89.47%), but five strains from cattle, deer, pony and a goat were assigned to A phylogroup. Most cattle strains belonged to O113, while O5 was just detected in ovine isolates, and O128 and O113 were present in caprine strains. In conclusion, the present study reveals the presence of potentially pathogenic genotypes among LEE-negative isolates and some host specificity related to subtilase variants and other virulence markers that may aid in source tracking of STEC during outbreaks.

scholarly journals Subtilase Cytotoxin-Coding Genes in Verotoxin-Producing Escherichia coli Strains from Sheep and Goats Differ from Those from Cattle

2011 ◽  
Vol 77 (23) ◽  
pp. 8259-8264 ◽  
Author(s):  
José A. Orden ◽  
Pilar Horcajo ◽  
Ricardo de la Fuente ◽  
José A. Ruiz-Santa-Quiteria ◽  
Gustavo Domínguez-Bernal ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Disease ◽  
Virulence Genes ◽  
Small Ruminants ◽  
Human Beings ◽  
Content Type ◽  
Sheep And Goats ◽  
E Coli ◽  
Healthy Cattle ◽  
Subtilase Cytotoxin

ABSTRACTSubtilase cytotoxin (SubAB) from verotoxin (VT)-producingEscherichia coli(VTEC) strains was first described in the 98NK2 strain and has been associated with human disease. However, SubAB has recently been found in two VT-negativeE. colistrains (ED 591 and ED 32). SubAB is encoded by two closely linked, cotranscribed genes (subAandsubB). In this study, we investigated the presence ofsubABgenes in 52 VTEC strains isolated from cattle and 209 strains from small ruminants, using PCR. Most (91.9%) VTEC strains from sheep and goats and 25% of the strains from healthy cattle possessedsubABgenes. The presence ofsubABin a high percentage of the VTEC strains from small ruminants might increase the pathogenicity of these strains for human beings. Some differences in the results of PCRs and in the association with some virulence genes suggested the existence of different variants ofsubAB. We therefore sequenced thesubAgene in 12 strains and showed that thesubAgene in most of thesubAB-positive VTEC strains from cattle was almost identical (about 99%) to that in the 98NK2 strain, while thesubAgene in most of thesubAB-positive VTEC strains from small ruminants was almost identical to that in the ED 591 strain. We propose the termssubAB1to describe the SubAB-coding genes resembling that in the 98NK2 strain andsubAB2to describe those resembling that in the ED 591 strain.

scholarly journals Genetic Characterization of Escherichia coli O104 Isolates from Different Sources in the United States

2011 ◽  
Vol 78 (5) ◽  
pp. 1615-1618 ◽  
Author(s):  
Lydia V. Rump ◽  
Sonya Bodeis-Jones ◽  
Jason Abbott ◽  
Shaohua Zhao ◽  
Julie Kase ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Virulence Genes ◽  
Genetic Characterization ◽  
The United States ◽  
Content Type ◽  
E Coli ◽  
Virulence Markers ◽  
Different Sources

ABSTRACTEscherichia coliO104 isolates collected from different sources in the United States were examined for virulence genes typical of enterohemorrhagicE. coliand those identified in the O104:H4 isolate associated with the 2011 German outbreak. The unexpected presence of virulence markers in these isolates highlights the importance of screening unusual and potentially pathogenic Shiga toxin-producingE. coliserotypes.

Occurrence of virulence-associated genes in clinical Enterococcus faecalis strains isolated in Londrina, Brazil

2004 ◽  
Vol 53 (11) ◽  
pp. 1069-1073 ◽  
Author(s):  
Elisa Bittencourt de Marques ◽  
Sérgio Suzart
Keyword(s):  
Enterococcus Faecalis ◽  
Virulence Genes ◽  
Epidemiological Studies ◽  
Wide Distribution ◽  
Virulence Determinants ◽  
Simultaneous Presence ◽  
Common Pattern ◽  
Clinical Strains ◽  
Virulence Markers ◽  
Serious Infections

Epidemiological studies have reinforced the importance of Enterococcus faecalis in causing serious infections, and to date, our understanding of how certain virulence factors are involved in the pathogenesis of enterococcal infections is still limited. The aim of the present study was to examine the occurrence of known virulence determinants in a group of E. faecalis strains isolated from different clinical sources in Brazil. A total of 95 E. faecalis strains were investigated for the presence of nine virulence genes including aggA, cylA, cylB, cylM, eep, efaA, enlA, esp and gelE by using PCR. The data showed a relatively wide distribution of the virulence genes among the investigated strains. The clinical strains carried at least one and concomitantly up to as many as eight virulence markers, with two or three being the most common pattern. Most of the strains carried efaA (58.9 %), eep (58.9 %) and esp (57.9 %) genes, whereas the remaining virulence markers were detected in variable percentages ranging from 9.5 to 45 %. Simultaneous presence of virulence markers was observed among clinical strains regardless of their sources. In this study, the efaA + esp + gelE + profile was the virulence genotype most frequently detected among E. faecalis strains. Finally, there was no significant association between virulence markers and clinical sources.

scholarly journals Prevalence of genes encoding extracellular virulence factors among meticillin-resistant Staphylococcus aureus isolates from the University Hospital, Olomouc, Czech Republic

2008 ◽  
Vol 57 (4) ◽  
pp. 403-410 ◽  
Author(s):  
P. Sauer ◽  
J. Síla ◽  
T. Štosová ◽  
R. Večeřová ◽  
P. Hejnar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Czech Republic ◽  
Virulence Factors ◽  
Virulence Factor ◽  
Antibiotic Susceptibility ◽  
University Hospital ◽  
Virulence Determinants ◽  
Virulence Markers ◽  
Genes Encoding ◽  
The University

A rather fast and complicated progression of an infection caused by some strains of Staphylococcus aureus could be associated with the expression and co-action of virulence factor complexes in these strains. This study screened the antibiotic susceptibility and prevalence of virulence markers in isolates of meticillin-resistant S. aureus (MRSA) obtained from patients hospitalized at the University Hospital in Olomouc, Czech Republic. A total of 100 isolates was screened for 13 genes encoding extracellular virulence determinants (tst, pvl, eta, etb, sea, seb, sec, sed, see, seg, seh, sei and sej) and for their distribution in sample types. Eighty-nine isolates were positive for at least one of the genes. Genes for etb, pvl, see and seh were not detected in any of the MRSA isolates. No statistically significant differences in the occurrence of the determinants studied among sample types were found.

scholarly journals Virulence Genes and Molecular Typing of Different Groups of Escherichia coli O157 Strains in Cattle

2009 ◽  
Vol 75 (19) ◽  
pp. 6282-6291 ◽  
Author(s):  
István Tóth ◽  
Herbert Schmidt ◽  
Gábor Kardos ◽  
Zsuzsanna Lancz ◽  
Kristina Creuzburg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Housekeeping Genes ◽  
Enzyme Analysis ◽  
Virulence Plasmid ◽  
O157 Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Strain Collection ◽  
Genes Encoding

ABSTRACT Characterization of an Escherichia coli O157 strain collection (n = 42) derived from healthy Hungarian cattle revealed the existence of diverse pathotypes. Enteropathogenic E. coli (EPEC; eae positive) appeared to be the most frequent pathotype (n = 22 strains), 11 O157 strains were typical enterohemorrhagic E. coli (EHEC; stx and eae positive), and 9 O157 strains were atypical, with none of the key stx and eae virulence genes detected. EHEC and EPEC O157 strains all carried eae-gamma, tir-gamma, tccP, and paa. Other virulence genes located on the pO157 virulence plasmid and different O islands (O island 43 [OI-43] and OI-122), as well as espJ and espM, also characterized the EPEC and EHEC O157 strains with similar frequencies. However, none of these virulence genes were detected by PCR in atypical O157 strains. Interestingly, five of nine atypical O157 strains produced cytolethal distending toxin V (CDT-V) and carried genes encoding long polar fimbriae. Macro-restriction fragment enzyme analysis (pulsed-field gel electrophoresis) revealed that these E. coli O157 strains belong to four main clusters. Multilocus sequence typing analysis revealed that five housekeeping genes were identical in EHEC and EPEC O157 strains but were different in the atypical O157 strains. These results suggest that the Hungarian bovine E. coli O157 strains represent at least two main clones: EHEC/EPEC O157:H7/NM (nonmotile) and atypical CDT-V-producing O157 strains with H antigens different from H7. The CDT-V-producing O157 strains represent a novel genogroup. The pathogenic potential of these strains remains to be elucidated.

Listeria monocytogenes From Farm to Fork in a Brazilian Pork Production Chain

2020 ◽  
Vol 83 (3) ◽  
pp. 485-490 ◽  
Author(s):  
DANILO A. L. SILVA ◽  
CLARISSE V. BOTELHO ◽  
BRUNA T. F. MARTINS ◽  
RAFAELA M. TAVARES ◽  
ANDERSON C. CAMARGO ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Control Measures ◽  
Production Chain ◽  
Pork Production ◽  
Pulsed Field ◽  
Genetic Profiles ◽  
Different Sources

ABSTRACT Listeria monocytogenes contamination was assessed in different steps of a pork production chain. Ten lots of pigs were sampled at termination barns, at slaughter (after bleeding, after buckling, after evisceration, and after final washing), at processing (knives, deboning tables, and employees' hands), and of end products (ribs, shoulder, ham, and sausage). All samples (n = 670) were subjected to L. monocytogenes detection, and the obtained isolates (n = 18, identified as Listeria spp.) were characterized by their biochemical characteristics, serogroups, virulence genes, pulsed-field gel electrophoresis profiles, antibiotic resistances (ampicillin, penicillin, gentamicin, and sulfamethoxazole-trimethoprim), and adhesion abilities. The results revealed the low occurrence of Listeria spp. in the evaluated pork production chain. However, four tested sausage samples (40%) were positive for Listeria spp., with L. monocytogenes identified in two (20%) of these samples. Ten isolates were identified as L. monocytogenes (eight from serogroup 1/2a or 3a and two from serogroup 4b, 4d, or 4e): all isolates were also positive for the virulence-related genes hlyA, iap, plcA, actA, inlA, inlB, inlC, and inlJ and susceptible to the tested antibiotics. One sausage sample was contaminated by both serogroups 1/2a or 3a and 4b, 4d, or 4e. Isolates from serogroup 1/2a or 3a obtained during visits 5 and 6 presented distinct genetic profiles by pulsed-field gel electrophoresis, indicating that contamination may come from different sources. The adhesion potential exhibited by Listeria spp. isolates (n = 18) ranged from weak (serogroup 4b, 4d, or 4e) to moderate (L. innocua and L. monocytogenes serogroup 1/2a or 3a). Despite the low occurrence of L. monocytogenes, pathogenic serogroups were detected in sausages, demanding control measures by the industry. HIGHLIGHTS

Virulence factors analysis and antibiotic resistance of uropathogenic Escherichia coli isolated from patients in northeast of Iran

2020 ◽  
Author(s):  
Mahdis Ghavidel ◽  
Tahere Gholamhosseini-Moghadam ◽  
Kimiya Nourian ◽  
Kiarash Ghazvini
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
High Rate ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Disk Diffusion Test ◽  
E Coli ◽  
Genes Encoding ◽  
Tract Infections

Background and Objectives: Escherichia coli is known to be the pathogen commonly isolated from those infected with uri- nary tract infections (UTIs). The aim of this study was to investigate the presence of E. coli virulence genes and antibiotics’ resistance pattern among clinical isolates in the Northeast of Iran. Relationships between virulence genes and antimicrobial resistances were studied as well. Materials and Methods: Three hundred isolates of E. coli were isolated from patients with UTIs that referred to Ghaem and Imam Reza hospitals (Mashhad, Iran) during August 2016 to February 2017. A multiplex PCR was employed to amplify the genes encoding pyelonephritis associated pili (pap), S-family adhesions (sfa), type1fimbriae (fimH) and aerobactin (aer). Disk diffusion test was performed to test the susceptibility of isolates to β-lactams, aminoglycosides, cephalosporins, quino- lone, fluoroquinolones, carbapenems and trimethoprim-sulfamethoxazole. Results: The PCR results identified the fimH in 78.4%, aer in 70.5%, sfa in 13.6% and the pap in 8.2% of isolates. The rates of antibiotic resistance of the isolates were as follows: 64.7% resistant to cephalosporins, 34% to trimethoprim-sul- famethoxazole, 31% to fluoroquinolones, 15.3% to aminoglycosides, 13.3% to β-lactams, 7.8% to quinolones and 4.4% to carbapenems. Significant relationships existed between pap and aer, pap and sfa, aer and fluoroquinolones also pap and cephalosporins. Conclusion: fimH and aer were found in > 50% of isolates suggesting the importance of both genes in UPEC. The majority of isolates had fimH as adhesion factor for colonization. Determining antibiotic resistance patterns in specific geographical areas is necessary for appropriate treatment of urinary tract infection. The high rate of resistance to cephalosporins is most likely due to incorrect drug administration

scholarly journals Isolation and Characterization of Potentially Pathogenic Antimicrobial-Resistant Escherichia coli Strains from Chicken and Pig Farms in Spain

2010 ◽  
Vol 76 (9) ◽  
pp. 2799-2805 ◽  
Author(s):  
Pilar Cortés ◽  
Vanessa Blanc ◽  
Azucena Mora ◽  
Ghizlane Dahbi ◽  
Jesús E. Blanco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Phylogenetic Analyses ◽  
Virulence Gene ◽  
E Coli ◽  
Isolation And Characterization ◽  
Zoonotic Risk ◽  
Poultry Farms ◽  
Pig Farms ◽  
Genes Encoding

ABSTRACT To ascertain whether on animal farms there reside extended-spectrum β-lactamase (ESBL) and plasmidic class C β-lactamase-producing Escherichia coli isolates potentially pathogenic for humans, phylogenetic analyses, pulsed-field gel electrophoresis (PFGE) typing, serotyping, and virulence genotyping were performed for 86 isolates from poultry (57 isolates) and pig (29 isolates) farms. E. coli isolates from poultry farms carried genes encoding enzymes of the CTX-M-9 group as well as CMY-2, whereas those from pig farms mainly carried genes encoding CTX-M-1 enzymes. Poultry and pig isolates differed significantly in their phylogenetic group assignments, with phylogroup A predominating in pig isolates and phylogroup D predominating in avian isolates. Among the 86 farm isolates, 23 (26.7%) carried two or more virulence genes typical of extraintestinal pathogenic E. coli (ExPEC). Of these, 20 were isolated from poultry farms and only 3 from pig farms. Ten of the 23 isolates belonged to the classic human ExPEC serotypes O2:H6, O2:HNM, O2:H7, O15:H1, and O25:H4. Despite the high diversity of serotypes and pulsotypes detected among the 86 farm isolates, 13 PFGE clusters were identified. Four of these clusters contained isolates with two or more virulence genes, and two clusters exhibited the classic human ExPEC serotypes O2:HNM (ST10) and O2:H6 (ST115). Although O2:HNM and O2:H6 isolates of human and animal origins differed with respect to their virulence genes and PFGE pulsotypes, the O2:HNM isolates from pigs showed the same sequence type (ST10) as those from humans. The single avian O15:H1 isolate was compared with human clinical isolates of this serotype. Although all were found to belong to phylogroup D and shared the same virulence gene profile, they differed in their sequence types (ST362-avian and ST393-human) and PFGE pulsotypes. Noteworthy was the detection, for the first time, in poultry farms of the clonal groups O25b:H4-ST131-B2, producing CTX-M-9, and O25a-ST648-D, producing CTX-M-32. The virulence genes and PFGE profiles of these two groups were very similar to those of clinical human isolates. While further studies are required to determine the true zoonotic potential of these clonal groups, our results emphasize the zoonotic risk posed especially by poultry farms, but also by pig farms, as reservoirs of ESBL- and CMY-2-encoding E. coli.

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