Shiga Toxin–Producing Escherichia coli in Wheat Grains: Detection and Isolation by Polymerase Chain Reaction and Culture Methods

Author(s):  
Sarah E. Remfry ◽  
Raghavendra G. Amachawadi ◽  
Mori Atobatele ◽  
Xiaorong Shi ◽  
Qing Kang ◽  
...  
Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 881
Author(s):  
Anna Szczerba-Turek ◽  
Bernard Kordas

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.


2003 ◽  
Vol 66 (7) ◽  
pp. 1277-1282 ◽  
Author(s):  
W. LI ◽  
M. A. DRAKE

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.


2019 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
D A Indah Gitaswari ◽  
Sri Budayanti

Penjamah makanan atau food handler memiliki risiko paling tinggi untuk terpapar penyakit yang disebabkan oleh bakteri. Penjamah makanan dapat bertindak sebagai carrier penyakit infeksi seperti demam tifoid, hepatitis A, dan diare. Hal ini disebabkan karena kurangnya kemampuan dari penjamah makanan dalam menjaga kebersihan. Bakteri patogen tersering sebagai penyebab diare adalah Escherichia coli yang diperkirakan sebagai penyebab 1.5 juta kematian per tahun. Bakteri Escherichia coli memiliki beberapa subtipe penyebab diare yang disebut Diarrheagenic Escherichia Coli (DEC) diantaranya adalah Enterotoxigenic Escherichia coli (ETEC), Enteropathogenic Escherichia coli (EPEC), Enteroinvasive Escherichia coli (EIEC), Enteroaggregative Escherichia coli (EAEC), Vero toxin-producing/Shiga toxin-producing Escherichia coli (VTEC/STEC), Enterohemorrhagic Escherichia coli (EHEC). Enterotoxigenic Escherichia coli (ETEC) dan Enteroaggregative Escherichia coli (EAEC) paling sering sebagai penyebab diare. Saat ini prevalensi subtipe Escherichia coli sebagai penyebab diare di Bali masih belum diketahui secara pasti. Untuk melihat prevalensi tersebut, pada penelitian ini akan diteliti tipe ETEC dan EAEC dengan menggunakan metode Polymerase Chain Reaction (PCR) unipleks. Sampel merupakan isolat Escherichia coli dari spesimen usap dubur penjamah makanan di Denpasar tahun 2015. Gen target untuk identifikasi ETEC dan EAEC adalah CVD432 (630 bp), LT (273 bp), dan STh (120 bp). Program PCR yang digunakan pada tahap pre denaturasi 95?C, denaturasi 95?C, suhu annealing 55?C, ekstensi 72?C, dan final ekstensi 72?C. Hasil penelitian didapatkan bahwa prevalensi bakteri Escherichia coli menunjukkan 40% memiliki hasil yang positif terhadap gen ETEC atau EAEC. Dari 40% sampel positif, 31,4% merupakan subtipe EAEC; 5,7% subtipe ETEC; dan 3% memiliki kedua gen yaitu ETEC dan EAEC. Kata kunci: Polymerase Chain Reaction, Enteroaggregative Escherichia coli, Enterotoxigenic Escherichia coli


2020 ◽  
Vol 17 (12) ◽  
pp. 782-791
Author(s):  
Sarah E. Remfry ◽  
Raghavendra G. Amachawadi ◽  
Xiaorong Shi ◽  
Jianfa Bai ◽  
Jason C. Woodworth ◽  
...  

2014 ◽  
Vol 143 (1) ◽  
pp. 94-103 ◽  
Author(s):  
M. Z. ISLAM ◽  
J. P. CHRISTENSEN ◽  
P. K. BISWAS

SUMMARYWe investigated faecal samples collected from the rectum of 518 cattle on 371 randomly selected smallholdings in Bangladesh for the presence of sorbitol non-fermenting (SN-F) shiga toxin-producingEscherichia coli(STEC). The SN-F isolates were tested for the presence ofrfbO157,stx1, stx2, eaeandhlyAgenes by polymerase chain reaction (PCR). Seven SN-F isolates lacking these genes were profiled by pulsed-field gel electrophoresis (PFGE) to verify their clonality. SN-FE. coliwas identified in 44 [8·5%, 95% confidence interval (CI) 6·4–11·2] samples; of these, 28 (5·4%, 95% CI 3·8–7·7) had shiga toxin-producing strains, although only two carried therfbO157 gene. Thirteen isolates carried thehlyAgene while 18 harboured theeaegene. Based on PFGE, six pulsotypes were observed among the seven isolates that had no virulence genes. To the best of our knowledge this is the first report on shiga toxin-producingE. colifrom direct rectal faecal samples of cattle on smallholdings.


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