Detection of Antibodies and Confirmation ofMycobacterium aviumSubspeciesparatuberculosisUsing Nested PCR in Bulk Milk Samples from Nakasongola and Sembabule Districts, Uganda

Julius Boniface Okuni,David Kalenzi Atuhaire,Lonzy Ojok,Sylvester Ochwo,William Olaho-Mukani,Magid Kisekka,Tony Oyo,Mathias Afayoa

doi:10.1155/2013/369730

Abstract

Mycobacterium avium subspecies paratuberculosis (MAP) is an emerging pathogen in many livestock and wildlife populations around the world. Concerns range from the serious economic impacts on livestock productivity to its suspected role in the human inflammatory bowel disease syndrome. Milk and faeces of infected animals are the main vehicles through which the organism spreads from infected to susceptible hosts. In this study, a survey was done in Nakasongola and Sembabule districts of Uganda involving a total of seven dairy collection centres to determine the prevalence of antibodies to MAP in bulk milk samples. The milk was tested with a commercial ELISA kit for MAP testing in milk. Positive and suspicious milk samples were further tested using nested PCR. Of the 257 milk samples tested, 11 (4.3%) were positive and five (1.9%) were suspicious. All the ELISA positive and suspicious milk samples were positive using nested PCR. The results show that MAP infection occurs in cattle from the two districts and highlight the need for a paratuberculosis control program in these and other districts where MAP infection has been reported.

Highlights

Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne’s disease or paratuberculosis in ruminants and some nonruminants [1]
When the primary PCR was done on the 11 ELISA positive and 5 suspicious samples, only 4 of the ELISA positives were found to be positive giving an amplicon of 217 bp
The finding that 4.3% of the milk contained antibodies to MAP using ELISA is close to figures in the previous seroprevalence studies from other districts in Uganda [20, 21] and the findings of a histopathology study in cattle from two abattoirs in Kampala [23], though those studies involved sera and histopathology and are not really comparable

Summary

Introduction

Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne’s disease or paratuberculosis in ruminants and some nonruminants [1]. During the course of time the animal begins to shed the organism in its faeces and milk which enables transmission to susceptible animals through ingestion of contaminated milk or fodder [2]. Prevalence of MAP in infected cattle has been determined by serological testing of serum and milk; culture of the organism from faeces and tissues; and histopathology and PCR on tissues, faeces, and milk [1]. Initial studies involving milk were primarily for determination of prevalence of infection in cattle, but focus has turned to the public health significance of MAP shedding into the milk [4]

Objectives

Methods

Results