Detection of Viable But Non-Culturable State of Escherichia coli O157:H7 Using Reverse Transcription PCR

Autor: Mohammad Khezri, Masoud Rezaei, Ashraf Mohabbati Mobarez, mehdi zolfaghari
Jazyk: English<br />Persian
Rok vydání: 2019
Předmět:
Zdroj: Iranian Journal of Medical Microbiology, Vol 12, Iss 6, Pp 390-398 (2019)
Druh dokumentu: article
ISSN: 1735-8612
2345-4342
Popis: Background and Aims: Many bacteria including Escherichia coli may enter into a viable but non-culturable (VBNC) state under unfavorable stresses, which are unable to be detected by culture-based methods. In this study, the use of Reverse Transcription PCR (RT-PCR) for detection of VBNC state of E. coli O157:H7 was investigated. Materials and Methods: Escherichia. coli O157:H7 was inoculated in distilled water and 30 percent salt water at room temperature. The cultivability of bacteria was determined using routine culture and colony counting on MacConkey agar. The RT-PCR of 16S rRNA gene involved direct extraction and purification of RNA, DNase I treatment for removing DNA contamination, cDNA synthesis and electrophoresis of PCR products of cDNA was used to detect viable E. coli O157:H7 under studied treatments and was compared with the results of RT-PCR of 16S rRNA gene of heat- killed bacteria. Results: The cultivability of bacteria was maintained during the study period in distilled water; however, the use of 30percent NaCl caused the bacteria to be non-cultivable on day 4. The RT-PCR of 16S rRNA showed the positive expression of this gene in cultivable and non-cultivable bacteria during the study period, whereas heat-killed bacteria were negative for this gene, which indicated the efficacy of RT-PCR of 16S rRNA in differentiation of alive from dead bacteria. Conclusions: Escherichia coli O157:H7 entered into the VBNC under 30 percent NaCl which can be associated with serious human health problems. RT-PCR can be used to detect bacteria in the VBNC state.
Databáze: Directory of Open Access Journals
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