scholarly journals Heat Inactivation of Mycobacterium avium subsp. paratuberculosis in Aseptically Prepared Ground Beef

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
Linda Saucier ◽  
Éveline Plamondon
Keyword(s):  
Heat Treatment ◽  
Mycobacterium Avium ◽  
Ground Beef ◽  
Etiologic Agent ◽  
Mycobacterium Avium Subsp ◽  
Heat Inactivation ◽  
Cooking Methods ◽  
Decimal Reduction Time ◽  
Mycobacterium Avium Subsp Paratuberculosis ◽  
D Values

Mycobacterium avium subsp. paratuberculosis (Map) is the etiologic agent of Johne’s disease in bovine and other ruminants. Concern for public health was raised when the organism was also suggested to be responsible for Crohn’s disease in humans, although the evidence remains inconclusive. Nonetheless, limiting human exposure to Map is viewed as a proper precautionary measure. Hence, the efficacy of heat treatment to control the organism in milk has been studied but it has not been studied to the same extend in meat. In this study, aseptically prepared ground beef was obtained from beef semimembranosus muscle and inoculated with two stains of Map (ATCC 7080 and gN27) to determine the decimal reduction time (D-value) and temperature sensitivity (z-value) for each strain. A 25 g sample of meat was inoculated with 100 ul of culture to a final concentration of 107 cfu/g. The inoculum was evenly distributed in the meat, which was spread in a thin (2 mm) layer of to maximise heat transfer. Treatments were performed at 55, 60, 65 and 70 °C for times allowing a minimum 5-log reduction. D-values decreased significantly with temperature (P < 0.05) ranging from 80.5 ± 6.1 minutes to 12 ± 1 seconds for both Map strains. When compared to Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 7080, D-values were significantly lower for E. coli (P < 0.05) whereas E. faecalis was not consistently more resistant than the two Map strains and, therefore, cannot be used as a surrogate strain for Map control with heat treatment. The z-values were not significantly different (P > 0.05) amongst the four strains and ranged from 5.6 ± 0.1 °C to 6.2 ± 0.3 °C. The results suggest that a low concentration of Map could be controlled with conventional cooking methods.

scholarly journals Mycobacterium avium subsp. paratuberculosisin Veterinary Medicine

2001 ◽  
Vol 14 (3) ◽  
pp. 489-512 ◽  
Author(s):  
N. Beth Harris ◽  
Raúl G. Barletta
Keyword(s):  
Mycobacterium Avium ◽  
Molecular Genetic ◽  
The United States ◽  
Etiologic Agent ◽  
Control Measures ◽  
Mycobacterium Avium Subsp ◽  
Economic Losses ◽  
Strain Identification ◽  
Virulence Determinants ◽  
Mycobacterium Avium Subsp Paratuberculosis

SUMMARY Mycobacterium avium subsp. paratuberculosis (basonym M. paratuberculosis) is the etiologic agent of a severe gastroenteritis in ruminants known as Johne's disease. Economic losses to the cattle industry in the United States are staggering, reaching $1.5 billion annually. A potential pathogenic role in humans in the etiology of Crohn's disease is under investigation. In this article, we review the epidemiology, pathogenesis, diagnostics, and disease control measures of this important veterinary pathogen. We emphasize molecular genetic aspects including the description of markers used for strain identification, diagnostics, and phylogenetic analysis. Recent important advances in the development of animal models and genetic systems to study M. paratuberculosis virulence determinants are also discussed. We conclude with proposals for the applications of these models and recombinant technology to the development of diagnostic, control, and therapeutic measures.

Inactivation of Mycobacterium avium subsp. paratuberculosis during Cooking of Hamburger Patties

2013 ◽  
Vol 76 (7) ◽  
pp. 1194-1201 ◽  
Author(s):  
PHILIPP HAMMER ◽  
HANS-GEORG C. WALTE ◽  
SÖ NKE MATZEN ◽  
JANN HENSEL ◽  
CHRISTIAN KIESNER
Keyword(s):  
Mycobacterium Avium ◽  
Egg Yolk ◽  
Mycobacterium Avium Subsp ◽  
Most Probable Number ◽  
Heat Inactivation ◽  
Inactivation Kinetics ◽  
Bacterial Reduction ◽  
Probable Number ◽  
Mycobacterium Avium Subsp Paratuberculosis ◽  
Cooking Times

The role of Mycobacterium avium subsp. paratuberculosis (MAP) in Crohn's disease in humans has been debated for many years. Milk and milk products have been suggested as possible vectors for transmission since the beginning of this debate, whereas recent publications show that slaughtered cattle and their carcasses, meat, and organs can also serve as reservoirs for MAP transmission. The objective of this study was to generate heat-inactivation data for MAP during the cooking of hamburger patties. Hamburger patties of lean ground beef weighing 70 and 50 g were cooked for 6, 5, 4, 3, and 2 min, which were sterilized by irradiation and spiked with three different MAP strains at levels between 102 and 106 CFU/ml. Single-sided cooking with one flip was applied, and the temperatures within the patties were recorded by seven thermocouples. Counting of the surviving bacteria was performed by direct plating onto Herrold's egg yolk medium and a three-vial most-probable-number method by using modified Dubos medium. There was considerable variability in temperature throughout the patties during frying. In addition, the log reduction in MAP numbers showed strong variations. In patties weighing 70 g, considerable bacterial reduction of 4 log or larger could only be achieved after 6 min of cooking. For all other cooking times, the bacterial reduction was less than 2 log. Patties weighing 50 g showed a 5-log or larger reduction after cooking times of 5 and 6 min. To determine the inactivation kinetics, a log-linear regression model was used, showing a constant decrease of MAP numbers over cooking time.

scholarly journals Isolation of Mycobacterium avium Subsp. Paratuberculosis in the Feces and Tissue of Small Ruminants Using a Non-Automated Liquid Culture Method

Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20
Author(s):  
Luigi De Grossi ◽  
Davide Santori ◽  
Antonino Barone ◽  
Silvia Abbruzzese ◽  
Matteo Ricchi ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Liquid Culture ◽  
Culture Media ◽  
Small Ruminants ◽  
Culture Method ◽  
Mycobacterium Avium Subsp ◽  
Type I ◽  
Culture Methods ◽  
Specific Pcr ◽  
Mycobacterium Avium Subsp Paratuberculosis

Paratuberculosis is a chronic disease of ruminants caused by Mycobacterium avium subsp. Paratuberculosis (MAP). Since isolation of MAP type I (S) is rarely reported in Italy, our research was aimed at isolating, by an inexpensive liquid culture manual method, this type of MAP isolates. At first, we used an ELISA to point out to serologically positive samples from five flocks. Secondly, we used a fecal direct IS900-qPCR on the ELISA positive samples, in order to detect shedder animals. Feces from IS900-qPCR positive samples were inoculated in solid and liquid culture media. IS900-qPCR was further used to test the growth of MAP isolates in liquid medium, which were further confirmed by f57-qPCR and submitted to typing by specific PCR in order to identify the MAP type. Twenty-eight samples (24 fecal and four tissutal samples) were processed by culture methods, resulting in the isolation of six type I MAP field isolates. Notably, no isolates were recovered by solid media, underlining the utility of this liquid method. Few data about this type of MAP are currently available in Italy, and further analyses should be carried out in order to study the origin and epidemiology of type I strains circulating in Italy.

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