Abstract
IntroductionSalmonella enterica are important food-borne pathogens that cause human gastroenteritis, bacteremia and subsequent focal infections. The incidences of food-borne salmonellosis due to non-typhoidal Salmonella serotypes are increasing periodically in Malaysia. Other than the two predominant non-typhoidal Salmonella serotypes, S. Typhimurium and S. Enteritidis, an emerging serotype, S. Weltevreden, is increasingly being isolated from hospitalized-gastroenteritis patients in Malaysia. Serotyping is the conventional method for differentiation of this pathogen from the 2500 other serotypes known to exist. However, this method has a number of disadvantages including low specificity and high cost. Therefore, a molecular method for identification of S. Weltevreden in clinical isolates based on amplification of a specific DNA sequence present in its genome is proposed. MethodsA total of 234 clinical isolates were collected from the Department of Clinical Microbiology and Parasitology, HUSM from year 2010-2012. There were 49 S. Weltevreden isolates which have been confirmed by the Institute of Medical Research (IMR) using conventional serotyping method. Two sets of primers targeting a unique gene in S. Weltevreden (SWE349) and a pan-Salmonella gene (invA284) were designed using Primer3 online software, and a multiplex-PCR (mPCR) assay was developed to detect S. Weltevreden in clinical isolates. The optimized S. Weltevreden mPCR assay was evaluated on a panel of known Salmonella and non-Salmonella spp. to determine the specificity and sensitivity of the mPCR assay. Results & DiscussionThe S. Weltevreden serovar specific primer, SWE349, and the internal control primer, invA284, resulted in 2 PCR products of 349bp and 284bp, respectively. The mPCR assay for S. Weltevreden targeting gene SWE349 showed 100% sensitivity (49/49) and specificity (36/36) in concordance with the conventional serotyping method in detecting only S. Weltevreden clinical strains, but not from the panel of 26 non-typhoidal Salmonella and 10 non- Salmonella isolates. ConclusionA cost effective, sensitive and specific mPCR assay has been developed for the detection and confirmation of Salmonella Weltevreden from clinical isolates of gastroenteritis patients, using genes SWE349 and invA284.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
