Seroprevalence, and molecular detection of Brucella abortus in cattle tissues from an abattoir in Namibia

Oscar Madzingira; Gottlieb Aikukutu; Fidelis Kandongo; Francis B Kolo; Siegfried Khaiseb; Georgina Tjipura-Zaire; Juliet N Kabajani; Albertina Musilika-Shilongo; Henriette van Heerden

doi:10.1080/20008686.2023.2229589

Seroprevalence, and molecular detection of Brucella abortus in cattle tissues from an abattoir in Namibia

Infect Ecol Epidemiol. 2023 Jun 28;13(1):2229589. doi: 10.1080/20008686.2023.2229589. eCollection 2023.

Authors

Oscar Madzingira^{1

2}, Gottlieb Aikukutu³, Fidelis Kandongo⁴, Francis B Kolo², Siegfried Khaiseb³, Georgina Tjipura-Zaire³, Juliet N Kabajani³, Albertina Musilika-Shilongo⁴, Henriette van Heerden²

Affiliations

¹ Department of Paraclinical Sciences, School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia.
² Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
³ Central Veterinary Laboratory, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia.
⁴ Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia.

Abstract

Brucellosis is a worldwide zoonosis that is endemic in Namibia. This study estimated seroprevalence of brucellosis, and determined the presence of Brucella infection in slaughtered cattle using the genus-specific 16-23S rRNA interspacer PCR (ITS-PCR), and the species-specific AMOS-PCR. Between December 2018 and May 2019, sera (n = 304), pooled lymph nodes (n = 304), and individual spleen (n = 304) were collected from slaughtered cattle from 52 farms. Sera were tested for anti-Brucella antibodies using the Rose Bengal test (RBT), and the complement fixation test (CFT). Seroprevalence was 2.3% (7/304) (RBT) and 1.6% (5/304) (CFT). Prevalence of positive herds was 9.6% (5/52). Lymph node (n = 200) and spleen (n = 200) samples from seronegative cattle tested negative for Brucella spp. DNA on ITS-PCR, but Brucella spp. DNA was detected in lymph nodes (85.7%, 6/7) and spleen (85.7%, 6/7) from RBT positive cattle. ITS-PCR confirmed isolates from lymph node (51.4%, 4/7) and spleen (85.7%, 6/7) as Brucella spp.; while AMOS-PCR and Brucella abortus species specific (BaSS) PCR confirmed the isolates as Brucella abortus, and field strains, respectively. Provision of adequate protective gear, and the promotion of brucellosis awareness among abattoir workers is recommended to prevent zoonotic infection.

Keywords: AMOS-PCR; Brucella abortus; ITS-PCR; Seroprevalence; abattoir; cattle.

Grants and funding

The Institute of Tropical Medicine (ITM), Antwerp (Belgium) partly funded the laboratory reagents used in this study. The funding body was not involved in either the design of the study or collection, analysis, and interpretation of data, nor the writing of the manuscript.