Contribution of InvA Gene PCR to Recovery of Salmonella spp. Strains

Aims: Salmonella infection remains a major public health concern worldwide, contributing the economic burden of both industrialized and developing countries through the costs associated with surveillance, prevention, and treatment of disease. This zoonosis has a harmful health and economic impact in terms of death, hospitalization, and destruction of livestock on farms. To adapts the means of control and prevention against this threat, the phenotypical characterization of Salmonella strains, both those recently identified and those which have been conserved for a long time, is necessary. So, the aim of this study was to check quality of the salmonella strains first stored in storage tubes in NRC of salmonella of Institute Pasteur of Côte d'Ivoire.

Place and Duration of Study: This study was done in Institute Pasteur of Côte d’Ivoire between July 2019 and October 2019.

Methodology: A total of 56 tubes used to store salmonella strains with few or no agar were analyzed to assess presence of Salmonella. The strains were first cultured in broth and then on selective agar (Hecktoen) medium and nutrient agar. Then, the Salmonella-specific InvA gene was directly detected in the tubes.

Results: The results obtained showed that the quality of the Salmonella strains initially conserved for at least 10 years had clearly deteriorated because none of them had been cultured after enrichment and culture on agar media. However, 73.21% of tubes not containing storage agar have traces of Salmonella DNA followed by molecular identification.

The preponderant contaminating bacterial flora was represented by Gram positive.

Conclusion: These results should encourage all laboratories to proceed immediately with the quality control of their strain collections for excellent biobanking.