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Isolation of acid-fast organisms from milk and oysters
Abstract:
Raw and pasteurized milk, as well as oysters collected from approved growing areas, were cultured for the presence of acid-fast organisms. Mycobacteria and nocardia were isolated from 68.8% of the raw milks, but none from the 43 pasteurized specimens. The 66 isolations were identified as follows: one M. marinum, two M. scrofulaceum, nine M. gordonae, seven M. flavescens, nine M. avium---M. intracellulare complex, 18 M. terrae complex, 12 M. fortuitum, six M. "parafortuitum" complex, and two Nocardia asteroides. From nine pooled samples of oysters 15 mycobacterial strains were cultured. These strains were identified as follows: three M. scrofulaceum, five M. gordonae, two M. avium--M. intracellulare complex, two M. terrae complex and three M. "parafortuitum" complex.
Insights
Acid-fast organisms, including Mycobacteria and Nocardia, were prevalent in raw milk but absent in pasteurized milk. Oysters also yielded various Mycobacteria strains, highlighting potential foodborne risks.
Area of Science:
- Microbiology
- Food Safety
- Environmental Health
Background:
- Acid-fast organisms, such as Mycobacteria and Nocardia, are known environmental bacteria.
- Contamination of food products like milk and oysters can pose public health risks.
Purpose of the Study:
- To investigate the presence and types of acid-fast organisms in raw milk, pasteurized milk, and oysters.
- To identify specific Mycobacteria and Nocardia species isolated from these food sources.
Main Methods:
- Samples of raw milk, pasteurized milk, and oysters from approved growing areas were collected.
- Cultures were performed to detect acid-fast organisms.
- Isolates were identified using standard microbiological techniques.
Main Results:
- Acid-fast organisms were detected in 68.8% of raw milk samples.
- No acid-fast organisms were found in 43 pasteurized milk samples.
- Fifteen Mycobacteria strains were isolated from nine pooled oyster samples, with species including M. scrofulaceum, M. gordonae, M. avium-intracellulare complex, M. terrae complex, and M. "parafortuitum" complex.
- A variety of Mycobacteria and Nocardia species were identified in raw milk, including M. marinum, M. scrofulaceum, M. gordonae, M. flavescens, M. avium-intracellulare complex, M. terrae complex, M. fortuitum, M. "parafortuitum" complex, and Nocardia asteroides.
Conclusions:
- Pasteurization effectively eliminates acid-fast organisms from milk.
- Raw milk and oysters can serve as reservoirs for various Mycobacteria species.
- Further research is needed to assess the public health implications of Mycobacteria in oysters.