In this study, three hundred presumptive Salmonella strains isolated from cattle faeces and raw beef samples were subjected to both preliminary and confirmatory tests specific for Salmonella. PCR assays revealed that 100%, 20% and 26.7% of the isolates were positive for 16S rRNA, fliC and fljB gene fragments, respectively. Large proportions (62.4 to 94.3%) of these isolates were multiple antibiotic resistant (MAR) strains that were resistant to three or more antibiotics belonging to different classes. MAR phenotypes Ab1, Ab2, Ab3, Ab7, Ab8, Ab9, Ab26 and Ab27 were dominant among the isolates. Cluster analysis of antibiotic inhibition zone diameter data revealed two major clusters (clusters 1 and 2), and each cluster contained two sub-clusters (1A, 1B, 2A and 2B). PCR data revealed that 27.1% and 30.7% of the isolates possessed the spvC and invA virulent genes, respectively. There was a significant correlation between the possession of MAR phenotypes and virulent gene determinants. Analysis of restriction fragment length polymorphism (RFLP) of 16S rRNA gene fragments using EcoRI and HaeIII showed that large proportions of isolates from beef and cattle faeces produced similar genetic fingerprints. From these results, it is suggested that Salmonella species in cattle are transmitted to beef and, therefore, the consumption of undercooked beef could pose severe health complications on consumers. These findings provide baseline data that could be of great epidemiological importance and, thus, the need to utilise more sensitive typing tools in determining the genetic relatedness of isolates from different sources.

Distribution of virulence factors, determinants of antibiotic resistance and molecular fingerprinting of Salmonella species isolated from cattle and beef samples: suggestive evidence of animal-to-meat contamination

Currently, Salmonella enterica is the most common bacterial foodborne pathogen, causing serious extraintestinal disease. Typing methods play an important role on pathogens’ source tracking, knowing...

https://www.tandfonline.com/doi/pdf/10.1080/13102818.2018.1451779

Genetic diversity of food originated Salmonella isolates

The genus of Salmonella is very polymorphic and comprised of a number of genetically closely related serotypes. It is one of the emerging pathogen in food-borne disease which is often found in contaminated chicken eggs. Salmonella enterica is considered one of the major pathogens in public health worldwide. A total of 31 Salmonella isolates identified by specific antisera, which included Salmonella enteritidis (51.6%), Salmonella typhimurium (25.8%), Salmonella infantis (19.4%) and Salmonella colindale (3.2%). DNA was extracted using phenol- chloroform- isoamylalchol method. All the isolates showed fliC gene (1500bp) by using specific primers. PCR products were subjected to digestion using HhaI restriction endonuclease. PCR- RFLP results showed 3 patterns between all isolates. Our research gained in this study demonstrated that using HhaI restriction endonuclease could differentiate Salmonella enteritidis and Salmonella colindale but there is similarity between pattern of Salmonella typhimurium and Salmonella infantis .

http://archrazi.areeo.ac.ir/article_103956_7c50e676da64ee29cdfbae30d14d6dad.pdf

Identification of Avian Salmonella Isolates by PCR-RFLP Analysis of a fliC Gene Fragment

The World Problem of Salmonellosis. Volume XIII

http://www.ijmcm.ir/article_513276_3c3854422eb25419124de1c72fdfdcb3.pdf

Pcr–rflp of isolated salmonella from poultry with sau3ai and hhai restriction endonucleases in arak

Restricted fragment length polymorphism (RFLP) was used in analyses on the typing and heterogeneity, typeability and polymorphism of the 16S rRNA, fliC and fimH genes in Salmonella Typhimurium isolates of varied origin. The digestion of PCR products with restriction enzymes EcoRV, ClaI, HaeIII and ScaI (fliC genes), HincII, ClaI, EcoRV and MluI (fimH genes) and EcoRI, SmaI and HaeIII (16S rRNA genes) generated two to four bands of ranging in size from 100 to 1,104 bp. Of all the restriction profiles obtained, only the ClaI profile for fimH could be used to classify Salmonella Typhimurium isolates into different groups. According to this profile, pattern A with uncut fimH was observed in eight isolates (36.36 %) and pattern B with 755- and 253-bp bands was observed in 14 isolates (63.63 %). No pattern was allotted for a special region or source. These results demonstrate that PCR-RFLP based on these genes showed good typeability but low discriminatory power. Moreover, the highly conserved nature of fliC, fimH and 16S rRNA illustrated in our study suggests the importance of these genes as immunization and diagnostic factors in Salmonella Typhimurium. Simultaneously, our results also illustrate the potential of ClaI-based fimH analysis as a marker for the sub-serotype level differentiation of Salmonella Typhimurium isolates.

PCR-RFLP analysis of fliC, fimH and 16S rRNA genes in Salmonella Typhimurium isolates of varied origin

Background: Enterotoxaemia represents one of the major limiting factors in small ruminant farming. Rapid lethal progression of the disease makes treatment impractical in most cases. Thus, suitable immunoprophylactic measures are necessary against this disease. The current study was aimed to test out the ability of novel alum precipitated oil adjuvant vaccine (AOV) for overcoming the difficulties associated with short-term immunity of current enterotoxaemia vaccines.
Methods: A new formulation named, AOV was prepared using a highly toxigenic strain of Clostridium perfringens type D. Immunogenicity and protective efficacy of this vaccine in comparison to presently available epsilon toxoid vaccine (TV) and alum precipitated vaccine (APV) was evaluated in the target species, sheep using indirect ELISA, mouse neutralization test (MNT).
Result: Among the three vaccines tested, AOV produced higher and persistent protective antibody titer up to 150 days post-immunization without any booster dose while APV and TV protected only up to 60th and 45th day respectively. All vaccinated animals remained healthy for the whole duration of the study with no systemic or local reactions. The present study delineates the superiority of AOV over presently available TV and APV for the prevention of an extremely lethal disease of sheep and goats.


A New Alum Precipitated Oil Formulation Vis-a-Vis Alum Precipitated and Toxoid Enterotoxaemia Vaccines for the Enhanced and Sustained Immune Response against Epsilon Toxin in Sheep

Sunita Chougule

Papers

PCR-RFLP analysis of fliC, fimH and 16S rRNA genes in Salmonella Typhimurium isolates of varied origin

A New Alum Precipitated Oil Formulation Vis-a-Vis Alum Precipitated and Toxoid Enterotoxaemia Vaccines for the Enhanced and Sustained Immune Response against Epsilon Toxin in Sheep