scholarly journals STX2 Gene

2020 ◽  
Author(s):  
Keyword(s):  
2003 ◽  
Vol 47 (3) ◽  
pp. 109-116 ◽  
Author(s):  
A.R. Blanch ◽  
C. García-Aljaro ◽  
M. Muniesa ◽  
J. Jofre

Verotoxigenic Escherichia coli strains have been related with waterborne outbreaks. Besides 0157:H7, several serotypes of E. coli and other enterobacteria have been implicated in outbreaks and reported to carry the shiga toxin genes. Shiga toxins, stx1 and stx2, are important virulence factors of these strains. These genes have been linked to bacteriophages and consequently are susceptible to lateral transmission. To better understand the ecology of these genes a study of the presence of the shiga toxin 2 gene (stx2) among coliform bacteria present in sewage samples was carried out. A procedure based on colony hybridisation was developed for the isolation of enterobacteria carrying this gene. Colony growth on Chromocult® agar was transferred to a membrane and hybridised with a gene specific probe. The procedure allowed detection of about one colony carrying the gene among around 1,000 faecal coliform colonies. The numbers of bacteria carrying the gene in sewage were also estimated by PCR indicating that the numbers of bacteria carrying the stx2 gene were about 1/1,000 faecal coliforms. The detected numbers by both methods were similar. Positive colony hybridisation was detected in four sewage origins. Fifty-two colonies showing positive signal were isolated from the Chromocult® agar plates, confirmed to be stx2 positive by PCR and phenotypically characterised. Results of the characterisation showed certain diversity among the isolates even in isolates from the same sample. Most of these isolates would not have been isolated with the methods regularly used for the isolation of E. coli 0157:H7 strains. The method will allow study of the numbers and characteristics of bacteria carrying the stx2 gene in different water environments and isolate them in order to determine their role in the spread of the gene.


2021 ◽  
Vol 10 (1) ◽  
pp. 51-54

Sorbitol non-fermenting Shiga toxin producing Escherichia coli (SNF-STEC) is considered as a significant emerging pathogen. Though, cattle and buffaloes are the chief reservoir, species like goat, sheep, deer and other ruminants can also harbor this pathogen. Therefore, this pathogen can easily be transmitted to human and other animals through food chain and their environment. The present study, aimed to ascertain the antibiotic resistance profile of SNF-STEC isolates from buffaloes as well as to detect the resistance genes. A total of 33 sorbitol non-fermenting (SNF) E. coli isolates were tested against ten commonly used antibiotics both in human and veterinary medicine. Results revealed that 78.8% isolates were resistant to sulfamethoxazole-trimethoprim and nalidixic acid whereas 60.6% to tetracycline and 48.5% to doxycycline. The majority of the isolates were found sensitive to both gentamycin and ciprofloxacin (90%) followed by erythromycin (66.7%) and ceftriaxone (51.5%). Of 33 SNF E. coli, 12 were STEC harboring both stx1 and stx2 gene that dictated 66.7% isolates were found resistant to sulfamethoxazole-trimethoprim and nalidixic acid followed by ampicillin (58.3%) and tetracycline (58.3%). blaTEM was detected in 66.7% ampicillin resistant isolates and sul2 was exposed in 34.6% sulfamethoxazole-trimethoprim resistant isolates. sul1 gene was negative for the sulfamethoxazole-trimethoprim resistant isolates.


2007 ◽  
Vol 59 (4) ◽  
pp. 825-831 ◽  
Author(s):  
V.P. Gonçalves ◽  
J.M. Marin

To determine the fate of Shiga toxigenic Escherichia coli (STEC) non-O 157 in composted manure from naturally colonized cattle, fresh manure was obtained from three cows carrying non-O157 STEC strains possessing the stx2 gene. Two composting systems were used: a 0.6m deep cave opened in the soil and an one meter high solid manure heap in a pyramidal architecture. Every day, for the 10 first days, and every five days for a month, one manure sample from three different points in both systems was collected and cultured to determine the presence of E. coli and the presence of the stx 2 gene in the cells. The temperature was verified at each sampling. STEC non-O157 E. coli cells survived for 8, 25 and 30 days at 42, 40 and 38ºC, respectively, in the deep cave and 4, 4 and 7 days at 65, 58 and 52ºC, respectively, in the heap, during the composting manure. Temperature and indigenous microorganisms appear to contribute to pathogen disappearance in the composting system. It is concluded that both composting systems were efficient to eliminate STEC cells. Land application of composted manure should minimize environmental risk associated with the dissemination of the pathogen.


2010 ◽  
Vol 32 (5) ◽  
pp. 681-688 ◽  
Author(s):  
Il-Wook Kim ◽  
Min-Hee Kang ◽  
Soon-Hwan Kwon ◽  
Seung-Hak Cho ◽  
Byung-Sun Yoo ◽  
...  

2020 ◽  
Vol 11 (4) ◽  
pp. 1030-1044
Author(s):  
Nydia Edith Reyes-Rodriguez ◽  
Jeannette Barba-León ◽  
Armando Navarro-Ocaña ◽  
Vicente Vega-Sanchez ◽  
Fabian Ricardo Gómez De Anda ◽  
...  

Shiga toxin E. coli (STEC) is an important pathogen responsible for foodborne illness, this have been related with epidemic outbreaks in the past, mainly because of consumption of bovine meat. The objective of this study was identify the serotypes and Stx2 subtypes and associate them with their possible epidemiology. There were analyzed a total of 65 isolates from the collection of the Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia of the Universidad Autónoma del Estado de México, from carcasses and feces of bovines at three different Municipal slaughterhouses. The identification of Stx2 gene by PCR at final point, sequencing and analyzed with the help of BLAST software. There were found O157:H7, O70:H16, O91:H10, O112ac:H2, O128ac:H26 serotypes, which have been reported to be present at infectious outbreaks previously by foodborne worldwide; 63.07% (41/65) of the Escherichia coli strains got amplified for Stx2 and after BLAS analysis it was confirmed its presence and a hypothetic protein. The presence of this serotypes in combination with different subtype’s, Stx2a, Stx2c, Stx2d, in carcasses and feces of bovine in must be considered as a potential risk for diseases an important problem of the public health.


2020 ◽  
Author(s):  
Brayan Stiven Arango-Gil ◽  
Sebastián Peña-Buitrago ◽  
Jhon Carlos Castaño-Osorio ◽  
Claudia Viviana Granobles-Velandia

ABSTRACTShiga toxin-producing Escherichia coli (STEC) is a bacterial pathogen that cause diarrhea and severe human diseases. Its principal virulence factor are the Shiga toxins Stx1 and Stx2 which have been identified diverse subtypes considered to be responsible for severe complications of STEC infection. These toxins are encoded in temperate bacteriophages and their expression is linked to phage lithic cycle, which is regulated by late genes and the Q anti-terminator protein. The aim of this study was to characterize biologically and molecularly STEC strains encoding stx2 gene isolated from cattle feces in Colombia. We selected six STEC strains, which were evaluated its Stx production, the Stx2 subtypes, induction of the lithic cycle of bacteriophages and its late region. The results evidenced two highlighted strains with high levels of Stx production and induction of the lithic cycle, compared with the others. Likewise, the strains evaluated showed three Stx2 subtypes: Stx2a, Stx2c, and Stx2d. Regarding the late region, most of the strains carried the qO111 allele and only one strain showed differences in the ninG gene. Although the sample was limited, variability was observed in the Stx production assay, induction of the lithic cycle, Stx2 subtypes and late region of the phages, which could indicate the diversity of the phages carrying STEC strains in Colombia.


2009 ◽  
Vol 160 (8) ◽  
pp. 585-591 ◽  
Author(s):  
Cristina Garcia-Aljaro ◽  
Eva Moreno ◽  
Antònia Andreu ◽  
Guillem Prats ◽  
Anicet R. Blanch

2016 ◽  
Vol 14 (1) ◽  
pp. 5-8
Author(s):  
M. M. Mamun ◽  
M. S. Parvej ◽  
S. Ahamed ◽  
J. Hassan ◽  
K. H. M. N. H. Nazir ◽  
...  

     Shigatoxigenic Escherichia coli (STEC) are major food-borne pathogens. They transmit to human through contaminated meat and meat products of animals and poultry, and frequently associated with various types of human illness including haemolytic uremic syndrome. This preliminary study showed the prevalence of STEC in 60 cloacal swab samples of live healthy broiler chickens collected randomly when sold at a wholesale market in Mymensingh district of Bangladesh. Isolation and identification of E. coli was carried out using Eosin Methylene Blue (EMB) agar media and 16S rRNA gene specific polymerase chain reaction (PCR). Among the 60 samples, 49 (81.67%) were found positive to E. coli. These E. coli isolates were screened for the detection of STEC by PCR using stx1 and stx2 gene specific primers. Among the 49 positive samples, 5 (10.20%) were found positive for stx1 gene, and 26 (53.06%) were positive for stx2 gene. In addition, 6 (12.24%) isolates were found positive to both stx1 and stx2 genes, and the remaining 12 (22.46%) were negative. The high prevalence ofSTEC in the broiler chicken alarms the public health impact as the people are always in close contact with these live broiler chickens in the open market as well as processing of meat at home before cooking. However, further studies are required to uncover the major source(s) for the transmission of STEC to human in ruralBangladesh.


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