1.A comparison of PCR and LAMP methods for detecting shiga toxin producing Escherichia coli
Nyamtuya N ; Sarantuya J ; Munkhdelger Ya ; Amgalanzaya D
Mongolian Medical Sciences 2022;200(2):3-7
Introduction:
PCR to detect and amplificate the virulence genes of STEC is specific and more sensitive, however, it takes five to six hours for whole test procedure and requires special lab instruments such as thermocycler. Loop-mediated isothermal amplification is a simple, rapid, specific and cost-effective nucleic acid amplification method by using four to six primers when compared to PCR, nucleic acid sequence-based amplification, self-sustained sequence replication and strand displacement amplification.
Materials and Methods:
In our study, we analyzed comparison of PCR and LAMP results on standard strain used quality control strain solution which diluted 1pg/µL DNA, 10 pg/µL DNA, 100 pg/µL DNA, 1 ng/μL DNA, 10 ng/μL DNA, and 100 ng/μL DNA concentration from LB agar cultures.
Research ethics:
Permission to submit the survey was granted by the Ethics Review Committee of the MNUMS and the survey was conducted in accordance with the rules and regulations.
Goal:
Detection and comparison of STEC by PCR and LAMP
Result:
Sensitivity of Stx1 and stx2 genes in PCR results are positive in 10 pg/µL DNA solution and
negative in 1pg/µL DNA. In LAMP test results showed that positive for all concentration. It
shows that LAMP method sensitivity is 10 times more than PCR.
Conclusion
It shows that LAMP method sensitivity is 10 times more than PCR. All in allLAMP test is cost
effective test with sensitive for detection STEC.
2.Presence and antibiotic resistance of diarrheagenic Escherichia coli in ready-to-eat salads
Unurmaa E ; Nyamtuya N ; Sarantuya J ; Tsolmon Ch ; Munkhdelger Ya
Mongolian Medical Sciences 2020;191(1):44-49
Introduction:
Foodborne diseases are a major public health concern worldwide. The report, which estimates the
burden of foodborne diseases – states that each year as many as 600 million, or almost 1 in 10
people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including
125 000 children under the age of 5 years. The 20.3% of diarrhea and 27.5% of die caused by
contaminated foods are diarrheagenic Escherichia coli (DEC).
Aim:
To identify of DEC and determine their antibiotic resistance from ready-to-eat salads
Material and Methods:
A total of 40 bagged salad mix samples were collected from food markets in Ulaanbaatar, Mongolia.
Escherichia coli (E.coli) strains were determined on the basis of MNS 6308:2012 standard and
confirmed by polymerase chain reaction (PCR) in samples. DEC was identified using multiplex PCR.
Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method.
Results:
Our results showed the presence of E. coli in 19 samples (47.5%). DEC isolates identified by multiplex
PCR were defined as follows: the presence of eae and bfp for EPEC, the presence of lt for ETEC,
the presence of ipaH for EIEC, the presence of stx1 and stx2 for EHEC, the presence of aap and
aggR for EAEC, and the presence of daaE for DAEC. The multiplex PCR assays detected EHEC 6
(31.6%), EPEC 5 (26.3%), EIEC 1 (5.3%). EAEC and ETEC were not detected in samples. The E.coli
isolates were 73.7% resistant to chloramphenicol as the first choice of treatment of diarrhea and high
resistance (68.4-94.7%) to the cephalosporins. In our country, cephalosporins are widely used in
medical practice for the treatment of infectious diseases.
Conclusion
In this study, about half of ready-to-eat salads are contaminated with E. coli. The three
types (EHEC, EPEC, EIEC) of DEC pathotypes were identified in the ready-to-eat salads and high
prevalent of antimicrobial resistance. Future research is required to track the contamination sources
and develop appropriate steps that should be taken by industry and retailers to reduce microbial
contamination in ready-to-eat salads.
3.A comparison of PCR and LAMP methods for detecting shiga toxin producing escherichia coli
Nyamtuya N ; Sarantuya J ; Amgalanzaya D ; Munkhdelger Ya
Mongolian Medical Sciences 2022;201(3):3-6
Introduction:
PCR to detect and amplificate the virulence genes of STEC is specific and more sensitive, however, it takes five to six hours for whole test procedure and requires special lab instruments such as thermocycler. Loop-mediated isothermal amplification is a simple, rapid, specific and cost-effective nucleic acid amplification method by using four to six primers when compared to PCR, nucleic acid sequence-based amplification, self-sustained sequence replication and strand displacement amplification.
Goal:
Detection and comparison of STEC by PCR and LAMP
Materials and Methods:
In our study, we analyzed comparison of PCR and LAMP results on standard strain used quality control strain solution which diluted 1pg/µL DNA, 10 pg/µL DNA, 100 pg/µL DNA, 1 ng/μL DNA, 10 ng/μL DNA, and 100 ng/μL DNA concentration from LB agar cultures.
Research ethics:
Permission to submit the survey was granted by the Ethics Review Committee of the MNUMS and the survey was conducted in accordance with the rules and regulations.
Result:
Sensitivity of Stx1 and stx2 genes in PCR results are positive in 10 pg/µL DNA solution and negative in 1pg/µL DNA. In LAMP test results showed that positive for all concentration. It shows that LAMP method sensitivity is 10 times more than PCR.
Conclusion
It shows that LAMP method sensitivity is 10 times more than PCR. All in allLAMP test is cost effective test with sensitive for detection STEC.