Salmonella Kentucky: prevalence and challenges in Nigeria and the Africa continent

Igomu, E. E.
Bacterial Vaccine Production Division, National Veterinary Research Institute, P. M. B. 01 Vom, Nigeria Correspondence to: elayonigomu@gmail.com; +2348032786224

Abstract:

Salmonella Kentucky is ubiquitous in most African countries and the multidrug resistant (MDR) strains remain underreported across the continent. In Nigeria, poverty, inter country livestock trades, nomadic system of cattle production, indiscriminate use of antibiotics and prevalent immuno-compromising diseases such as human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and tuberculosis are factors that have enabled ease of transmission and complications of S. Kentucky infections. In the present decade, S. Kentucky is reported to be the most prevalent serovar associated with poultry in Nigeria, but very few reports underline the risk associated with consumption of poultry and acquisition of MDR S. Kentucky strains. The Nigerian poultry is one of the most commercialized subsectors of Nigerian agriculture, therefore, the presence of S. Kentucky especially strains carrying broad spectrum antimicrobial resistance pose a great risk to public health. The lack of proper monitoring, surveillance, isolation and control of the multidrug resistant S. Kentucky will remain a challenge to the export potential of the Nigerian poultry subsector and livestock in general. As a nation, modalities and actions against the smuggling of poultry products, indiscriminate use of antibiotics and nomadic system for the production of dairy and beef that promotes spread of virulent strains of Salmonellae must change. The impact of non-typhoidal salmonellosis in humans in Nigeria also remains under studied and under reported, especially those caused by S. Kentucky ST198. Compounding these concerns is the lack of commercial veterinary or human vaccines against S. Kentucky or where vaccines against the broad serogroup C non-typhoidal Salmonella (NTS) are available, they are rarely supplied, with no evidence they could be cross-protective. This review emphasizes the emergence and widespread occurrence of MDR S. Kentucky strains on the African continent, and discussed risk factors contributing to its spread in Nigeria and the potential public health challenge especially to high-risk immunocompromised individuals.
Keywords: Salmonella Kentucky, ST198 strain, multidrug resistant, tuberculosis, HIV/AIDS, Nigeria, Africa
Received April 30, 2020; Revised May 8, 2020; Accepted May 10, 2020
Copyright 2020 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License <a rel=”license” href=”//creativecommons.org/licenses/by/4.0/”, which permits unrestricted use, distribution and reproduction in any medium, provided credit is given to the original author(s) and the source.
Salmonella Kentucky: prévalence et défis au Nigeria et sur le continent africain
Igomu, E. E.
Division de la production de vaccins bactériens, Institut national de recherche vétérinaire, P. M. B. 01 Vom, Nigéria Correspondance à: elayonigomu@gmail.com; +2348032786224 Continue reading “Salmonella Kentucky: prevalence and challenges in Nigeria and the Africa continent”

Production and efficacy testing of live attenuated and inactivated vaccines against experimental Salmonella Kentucky infection in broiler chickens

*1Igomu, E. E., 2Fagbamila, I. O., 3Elayoni, E. E., 1Pwajok, D., 1Agu, G. C., 4Govwang, P. F., 5Msheliza, E. G., 5Oguche, M. O., and 6Mamman, P. H.

*1Bacterial Vaccine Production Division, National Veterinary Research Institute, P.M.B. 01, Vom, Nigeria

2Bacterial Research Division, National Veterinary Research Institute, Vom, Nigeria

3Biological Science Department, Adamawa State University Mubi, Adamawa State, Nigeria

4Livestock Investigation Division, National Veterinary Research Institute, Vom, Nigeria

5Central Diagnostic Division, National Veterinary Research Institute, Vom, Nigeria 6Department of Veterinary Microbiology, Ahmadu Bello University, Zaria, Nigeria *Correspondence to: elayonigomu@gmail.com; +2348032786224

Abstract:
Background: Salmonella Kentucky is of great veterinary and public health concern and exhibits the capacities to emerge as the most prominent Salmonella serotype in human disease. The objective of this study is to evaluate the efficacy of prepared live attenuated and inactivated vaccines against experimentally induced salmonellosis caused by S. Kentucky in broiler chickens.

Methods: Field isolate of S. Kentucky was obtained from the National Veterinary Research Institute Vom, Nigeria and used in the preparation of experimental vaccines. Broiler chickens purchased and ascertained to be free of Salmonellae were randomly distributed into three experimental groups of 20 chicks each. Five-bromouracil at a concentration of 1000μg/ml was used in attenuation of S. Kentucky in preparation of the live vaccine and 0.6% formaldehyde was used in inactivation of S. Kentucky for preparation of the inactivated vaccine. Group 1 chicks were immunized with the live vaccine subcutaneously at 0.5ml per bird, group 2 received 1ml of the inactivated vaccine subcutaneously, and group 3 served as unvaccinated/control.

Results: There was 100% faecal inhibition and 100% vaccinal efficacy in broiler chickens immunized with the live vaccine on day 56 of age, and 49.6% faecal inhibition and 82.8% vaccinal efficacy in broiler chickens immunized with the inactivated vaccine on day 56 of age when compared with the unvaccinated control. The vaccinated birds also showed higher antibody (IgY) titre levels from day 21 to day 56 of age (p<0.001) on all sampling days when values were compared with the unvaccinated birds.

Conclusion: The interplay between vaccination protocol that includes administration of live attenuated or inactivated S. Kentucky vaccines and developed antibody (IgY) can reduce intestinal colonization by S. Kentucky and subsequent shedding of the serovar in faeces.

Keywords: Salmonella Kentucky, 5-bromouracil, IgY, Antibody, Vaccine

Received January 9, 2019; Revised April 11, 2020; Accepted April 12, 2020

Copyright 2020 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License <a rel=”license” href=”//creativecommons.org/licenses/by/4.0/”, which permits unrestricted use, distribution and reproduction in any medium, provided credit is given to the original author(s) and the source.

Production et tests d’efficacité de vaccins vivants atténués et inactivés contre une infection expérimentale à Salmonella Kentucky chez des poulets de chair

*1Igomu, E. E., 2Fagbamila, I. O., 3Elayoni, E. E., 1Pwajok, D., 1Agu, G.C., 4Govwang, P. F., 5Msheliza, E. G., 5Oguche, M. O., et 6Mamman, P. H. Continue reading “Production and efficacy testing of live attenuated and inactivated vaccines against experimental Salmonella Kentucky infection in broiler chickens”