Volume 21, Issue 4 (Iranian South Medical Journal 2018)
Iran South Med J 2018, 21(4): 276-286 |
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Ghazal Noorabadi1 
, Mozhgan Siyavashi1 , Katayon Vahdat2 , Omid Gharibi3 , Mehdi Mahmudpour2 , Mohammad Ali Haghighi * 4
, Mozhgan Siyavashi1 , Katayon Vahdat2 , Omid Gharibi3 , Mehdi Mahmudpour2 , Mohammad Ali Haghighi * 4
1- Student Research Committee, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
2- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
3- Reference laboratory, Provincial Health Center, Vice Chancellery Health, Bushehr University of Medical Sciences, Bushehr, Iran
4- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
Department of Microbiology & Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran , mahaghighy@gmail.com
2- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
3- Reference laboratory, Provincial Health Center, Vice Chancellery Health, Bushehr University of Medical Sciences, Bushehr, Iran
4- The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
Department of Microbiology & Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran , mahaghighy@gmail.com
Abstract: (3948 Views)
Background: The Shiga cytotoxin (Stx) is involved in serious human intestinal diseases. Recently stx has been found in non-S dysenteriae1 Shigella species. This study aimed to identify stx gene in clinical strains of Shigella isolated from two shigellosis outbreaks in previous years in Bushehr, southwest of Iran.
Materials and Methods: Purified DNA of 143 Shigella isolates was used for PCR to detect stx and ipaH genes. The number of PCR products in various Shigella species isolates was sequenced with the same primers (evt) used to amplify this region.
Results: Fourteen (22.3%) out of 63 shigella isolates related to previous shigellosis outbreaks during 2002-2004 contained the PCR positive result with evt primers. The sequencing results indicated that the evt PCR product had the most identity (97%) with Shigella dysentery shiga toxin subunit A. All clinical shigella strains isolated during 2013-2015 yielded PCR negative results with primers stx and evt. PCR results revealed that ipaH was present in all isolates. According to biochemical and species-specific antiserum tests, the stx gene harboring isolates included 9 (14.3%) S. flexneri, 4 (6.4%) S. sonnei, and 1(1.6%) S. boydii.
Conclusion: The stx gene has already been distributed in different Shigella species of Bushehr region. However, the absence of this gene in the clinical isolates of recent shigellosis outbreaks may be temporary. Because stx gene increases the pathogenic potential of Shigella, it is necessary to monitor the prevalence of the stx harboring Shigella species by molecular methods in the future.
Materials and Methods: Purified DNA of 143 Shigella isolates was used for PCR to detect stx and ipaH genes. The number of PCR products in various Shigella species isolates was sequenced with the same primers (evt) used to amplify this region.
Results: Fourteen (22.3%) out of 63 shigella isolates related to previous shigellosis outbreaks during 2002-2004 contained the PCR positive result with evt primers. The sequencing results indicated that the evt PCR product had the most identity (97%) with Shigella dysentery shiga toxin subunit A. All clinical shigella strains isolated during 2013-2015 yielded PCR negative results with primers stx and evt. PCR results revealed that ipaH was present in all isolates. According to biochemical and species-specific antiserum tests, the stx gene harboring isolates included 9 (14.3%) S. flexneri, 4 (6.4%) S. sonnei, and 1(1.6%) S. boydii.
Conclusion: The stx gene has already been distributed in different Shigella species of Bushehr region. However, the absence of this gene in the clinical isolates of recent shigellosis outbreaks may be temporary. Because stx gene increases the pathogenic potential of Shigella, it is necessary to monitor the prevalence of the stx harboring Shigella species by molecular methods in the future.
Type of Study: Original |
Subject:
Microbiology and Immunology
Received: 2018/01/11 | Accepted: 2018/03/11 | Published: 2018/09/4
Received: 2018/01/11 | Accepted: 2018/03/11 | Published: 2018/09/4
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