Genetic Characterization of Shiga Toxin-producing &lt;i&gt;Escherichia coli&lt;/i&gt; Strains Isolated from Imported Beef Meat in Malaysia Using Polymerase Chain Reaction Analysis

SummaryFrom February to July of 1994, 328 faecal samples from 32 herds were collected and verotoxin-producingEscherichia coli(VTEC) found on 84% of the farms. The proportion of animals infected varied from 0–63%. VTEC were recovered from 52 (20%) of 257 cows and from 16 (23%) of 71 calves. Although the VTEC belonged to 25 different serogroups, 7 (O8. O20, O22, O77, O113, O126 and O162) accounted for 46% of strains. Nearly 45% of the 83 bovine VTEC strains belonged to serogroups associated with haemorrhagic colitis and haemolytic uraernic syndrome in humans. However, only 2 (2%) of 83 VTEC strains isolated from cattle belonged to enterohaemorrhagicE. coli(EHEC) serotypes (O26:H11 and O157:H7), and only 8 (10%) were positive for the attaching and effacingE. coli (eae)gene sequence. Polymerase chain reaction (PCR) showed that 17 (20%) of VTEC strains carried VT1 genes. 43 (52%) possessed VT2 genes, and 23 (28%) carried both VT1 and VT2 genes. Characterization of VTEC isolates revelated a heterogeneous population in terms of serogroup and toxin type in the positive herds. This study confirms that healthy cattle are a reservoir of VTEC, but, the absence ofeaegenes in most bovine VTEC strains suggests that they may be less virulent for humans thaneae-positive EHEC.

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Fallow Deer (Dama dama) as a Reservoir of Shiga Toxin-Producing Escherichia coli (STEC)

Animals ◽

10.3390/ani10050881 ◽

2020 ◽

Vol 10 (5) ◽

pp. 881

Author(s):

Anna Szczerba-Turek ◽

Bernard Kordas

Keyword(s):

Escherichia Coli ◽

Polymerase Chain Reaction ◽

Foodborne Pathogens ◽

Shiga Toxin ◽

Fallow Deer ◽

Dama Dama ◽

Chain Reaction ◽

E Coli ◽

Deer Population ◽

Polymerase Chain

Shiga toxin-producing Escherichia (E.) coli (STEC) are responsible for the outbreaks of serious diseases in humans. Only a few reports on fallow deer as a reservoir of foodborne pathogens have been published to date. The purpose of this study was to determine the occurrence of STEC strains in the fallow deer population in Poland. In all, 94 fallow deer swabs were tested. Polymerase chain reaction (PCR) was performed to detect the virulence profile of stx1, stx2 and eae or aggR genes, to identify the subtypes of stx1 and stx2 genes and to perform O and H serotyping. STEC and attaching and effacing (AE)-STEC were identified in 13 isolates (13.83%). The most hazardous virulence profile was detected in three strains, namely stx2d serotype O103:HNM, eae/stx1a serotype O26:HNM and eae/stx1a serotype O157:H7. The predominant stx gene was stx2, which was identified in 76.92% of isolates. E. coli O157 was detected in 4/94 (4.26%). Other E. coli serogroups, O26, O103, O111 and O145, were identified in 14/94 fallow deer (14.89%). The present findings suggest that fallow deer are carriers of STEC/AE-STEC that are potentially pathogenic to humans.

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The Polymerase Chain Reaction (PCR) in the routine genetic characterization of retinoblastoma: A tool for the clinical laboratory

Survey of Ophthalmology ◽

10.1016/s0039-6257(96)00004-5 ◽

1997 ◽

Vol 41 (4) ◽

pp. 331-340 ◽

Cited By ~ 4

Author(s):

Domenico Mastrangelo ◽

Nicola Squitieri ◽

Stefano Bruni ◽

Theodora Hadjistilianou ◽

Renato Frezzotti

Keyword(s):

Polymerase Chain Reaction ◽

Genetic Characterization ◽

Clinical Laboratory ◽

Chain Reaction ◽

Polymerase Chain

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Detection of Viable Shiga Toxin–Producing Escherichia coli by Quantitative Competitive Polymerase Chain Reaction

Journal of Food Protection ◽

10.4315/0362-028x-66.7.1277 ◽

2003 ◽

Vol 66 (7) ◽

pp. 1277-1282 ◽

Cited By ~ 2

Author(s):

W. LI ◽

M. A. DRAKE

Keyword(s):

Escherichia Coli ◽

Polymerase Chain Reaction ◽

Cell Viability ◽

Shiga Toxin ◽

Ground Beef ◽

Multiple Time ◽

Chain Reaction ◽

Competitive Polymerase Chain Reaction ◽

E Coli ◽

Polymerase Chain

With the use of Escherichia coli O157:H7 as a model, a procedure for the quantitative detection of viable Shiga toxin–producing E. coli (STEC) in broth and cooked ground beef enrichments with multiple–time point quantitative competitive polymerase chain reaction (QC-PCR) was developed. The A subunit (a 401-bp fragment) of the stx2 gene was chosen as a target sequence. Immunomagnetic separation (IMS) was used to isolate and concentrate cells from ground beef enrichments. Cell viability was confirmed on the basis of the quantitative increase in the signal of target bands from QC-PCR across multiple time points. The application of IMS increased detection limits relative to those for QC-PCR without IMS. E. coli O157:H7 inoculated at 0.20 CFU/g of cooked ground beef (25 g of ground beef plus 225 ml of Bacto modified EC medium plus novobiocin) was detected and confirmed to be viable in <15 h. A DNA-based molecular approach can be used to determine cell viability.

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Detection and characterization of verotoxin-producing strains among sorbitol non-fermenting Escherichia coli

Eastern Mediterranean Health Journal ◽

10.26719/2001.7.4-5.756 ◽

2001 ◽

Vol 7 (4-5) ◽

pp. 756-762

Author(s):

A. Jafari ◽

M. Katouli ◽

F. Shokouhi ◽

S. Bouzari

Keyword(s):

Escherichia Coli ◽

Polymerase Chain Reaction ◽

Antibiotic Resistance ◽

Multidrug Resistance ◽

High Rate ◽

Cell Adherence ◽

Chain Reaction ◽

Resistance Transfer ◽

Polymerase Chain

The presence of genes for verotoxin 1 and 2 [VT1 and 2] among sorbitol non-fermenting Escherichia coli isolates from diarrhoeal cases was assessed using polymerase chain reaction assay. Of 60 [88%] positive isolates, 37 [62%] harboured VT1 and 23 [38%] both VT1 and VT2. In HeLa cell adherence assay, 48 [71%] isolates exhibited mannose-resistant adherence to HeLa cells. Multidrug resistance was observed in 56 [82%] isolates, with ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-trimethoprim and tetracycline pattern being the most common. There were 13 common and 22 single biochemical phenotypes identified. Isolates belonging to common biochemical phenotypes normally had a similar pattern of adherence and VT production, but differed greatly in their pattern of antibiotic resistance, pointing to a high rate of antibiotic-resistance transfer among these isolates.

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