Clinical disease and stage of lactation influence shedding of Mycobacterium avium subspecies paratuberculosis into milk and colostrum of naturally infected dairy cows

Abstract

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of Johne's disease (JD). One mode of transmission of MAP is through ingestion of contaminated milk and colostrum by susceptible calves. The objective of this study was to determine if the amount of MAP shed into the milk and colostrum of infected cows was affected by severity of infection as well as the number of days in milk (DIM). Milk was collected over the 305-d lactation period from naturally infected cows in the asymptomatic subclinical (n=39) and symptomatic clinical (n=29) stages of disease, as well as 8 noninfected control cows. All milk samples were assayed for MAP by culture on Herrold's egg yolk medium and either BACTEC 12B (Becton Dickinson, Franklin Lakes, NJ) or para-JEM (Thermo Fisher Scientific, Trek Diagnostic Systems Inc., Cleveland, OH) liquid medium, and by direct PCR for the IS900 target gene. Mycobacterium avium ssp. paratuberculosis was detected in 3.8, 4.1, and 12.6% of milk samples collected from cows with subclinical JD after culture in Herrold's egg yolk medium, liquid medium, and direct PCR, respectively. The frequency of MAP positivity increased to 12.9, 18.4, and 49.2% of milk samples collected from cows with clinical JD by these same methods, respectively. None of the milk samples collected from control cows was positive for MAP by any detection method. Viable MAP was primarily isolated from milk and colostrum of subclinically and clinically infected cows collected in early lactation (DIM 0-60), with negligible positive samples observed in mid (DIM 60-240) and late (DIM 240-305) lactation. This study demonstrates that shedding of MAP into milk is affected by infection status of the cow as well as stage of lactation, providing useful information to producers to help break the cycle of infection within a herd.

Factors associated with Mycobacterium avium subsp. paratuberculosis in dairy cows from Northern Antioquia, Colombia

“…Mycobacterium avium subspecies paratuberculosis (MAP) has been isolated from colostrum of subclinically infected cows (Streeter et al ., 1995;Pithua et al ., 2011;Stabel et al ., 2014;Laurin et al ., 2015;Jenvey et al ., 2016). Additionally, the practice of feeding calves with colostrum collected from known MAP infected cows (Dieguez et al ., 2008), as well as the practice of feeding calves pooled colostrum from multiple cows (Nielsen et al ., 2008) have been identified as risk factors for MAP in dairy herds.…”

Conceptos sobre inocuidad en la producción primaria de la leche.

“…Atribución-No-Comercial SinDerivadas 3.0 Costa Rica abortus (IMCSF 2002;Stabel et al 2014) y Arcobacter spp. (Serraino & Giacometti 2014).…”

“…(Serraino & Giacometti 2014). Al respecto, Stabel et al (2014) demostraron que la excreción de MAP a la leche se ve afectada por el estado de infección de la vaca (subclínica o clínica), así como la fase de la lactancia. Adicionalmente, Cronobacter sakazakii (antes llamado Enterobacter sakazakii) es causante de ETA, principalmente en niños menores de 6 meses, cuya principal vía de transmisión son las fórmulas lácteas infantiles (Petrola et al 2013).…”

Mycobacterium avium Subspecies paratuberculosis Recombinant Proteins Modulate Antimycobacterial Functions of Bovine Macrophages

“…The dairy industry incurs substantial economic losses due to reduced milk production, premature culling and reduced slaughter value [3]. The bacterium is shed in the feces and milk of infected animals, primarily in the clinical phase of disease [4]. Transmission of disease can occur by ingestion of the bacterium through manure-contaminated feedstuffs and pastures or by colostrum and milk, passed from the infected dam to the calf [4, 5].…”