Thermal inactivation of several Mycobacterium spp. in milk by pasteurization

Abstract

The thermal inactivation of Mycobacterium avium, Myco. bovis, Myco. fortuitum, Myco. intracellulare and Myco. kansaii in milk at 63.5 degrees C was investigated. Survivors were enumerated after heating for 0, 5, 10, 15, 20 and 30 min and thermal death curves were constructed for each species. Mycobacterium bovis and Myco. fortuitum were found to exhibit linear thermal death curves and neither species demonstrated any survival after heating at 63.5 degrees C for 30 min (equivalent to holder pasteurization). In contrast, Myco. avium, Myco. intracellulare and Myco. kansasii yielded thermal death curves which exhibited significant 'tailing' and all three strains survived holder pasteurization.

Methods for thermal inactivation of pathogens in mozzarella: a comparison between stretching and pasteurization

“…Regardless of our results, M. bovis and M. fortuitum were completely inactivated by holder pasteurization in the studies published by Kells and Lear (1960), Harrington and Karlson (1965), and Grant et al (1996). Data on the reduction of Mycobacterium avium subsp.…”

“…The decision to use Mycobacterium fortuitum instead of Mycobacterium bovis in this study was due to observations that both species show similar thermal inactivation kinetics (Grant et al, 1996), and to the fact that M. fortuitum grows faster and is less pathogenic to human beings than M. bovis, posing less risk to the handler (WHO, 1984).…”

Isolation and identification of mycobacteria from livestock specimens and milk obtained in Brazil

“…Particularly in immunocompromised patients, the mycobacterial infection caused by M. avium is second only to tuberculosis in prevalence in Brazil (Saad et al 1997). Although it has been established that pasteurization kills M. tuberculosis in milk (Hosty & McDurmont 1975), survival of some nontuberculous Mycobacterium species after simulated laboratory pasteurization has been reported (Harrington & Karison 1965, Grant et al 1996, Stabel et al 1997. The organisms found among our pasteurized samples are among the species known to survive pasteurization.…”

New Emerging and Re-Emerging Bacterial Foodborne Pathogens

“…60 , Amerika Birleşik Devletleri'nde süt sığırcılığındaki hayvanların %25, etçi olanların ise %8 oranında infekte olabileceğini bildirmiş-lerdir. Bunun yanı sıra etkenin infekte hayvanların sütlerinde mevcut olduğu [60][61][62] ve pastörizasyon sıcaklık-zaman düzen-lerinde canlı kaldığı belirtilmektedir 52,[60][61][62][63][64] .…”