Mix-infection of S. Typhi and ParaTyphi A in Typhoid Fever and Chronic Typhoid Carriers: A Nested PCR Based Study in North India
Published: November 1, 2014 | DOI: https://doi.org/10.7860/JCDR/2014/.5107
Chandra Bhan Pratap, Gopal Kumar, Saurabh Kumar Patel, Vijay K Shukla, Kailash Kumar, Tej Bali Singh, Gopal Nath
1. PhD Student, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
2. Senior Resident, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
3. PhD Student, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
4. Professor, Department of General Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
5. Professor, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
6. Professor, Department of Community Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
7. Professor, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Correspondence
Dr. Gopal Nath,
Professor, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005, India.
Phone : +91-9335058394, E-mail : gopalnath@gmail.com
Introduction: Enteric fever is a systemic disease caused by Salmonella organism such as serotypes Typhi and ParaTyphi A, B, C. Salmonella ParaTyphi A contributes more than 50% of all the enteric fever cases and it has recently been projected as an emerging pathogen.
Materials and Methods: The present study was aimed to detect Salmonella Typhi and ParaTyphi A in urine, blood and stool specimens collected from cases of enteric fever (110), chronic typhoid carriers (46) and healthy controls (75) to explore the possibility of mixed infection by nested PCR. A new nested PCR primer was designed targeting putative fimbrial protein (stkG) gene which is one of the fimbrial gene families to Salmonella ParaTyphi A and for S. Typhi already reported primers targeting flagellin (fliC) gene.
Results: Large volume of urine specimens (15 ml) was found to be the best for detection of Salmonella serotypes. The urine sample was found to have mixed-infection by both the serotypes in 40.9% of the cases but lower in blood (27.3%) and stool (13.6%).
Conclusion: The present study concludes that occurrence of mixed infection may be quite frequent in typhoid and chronic typhoid carriers’ individuals, although the reported recent rise in ParaTyphi A incidence may not be real.
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