Characterization of Coliphages Recovered from Foods According to Temperature of Infectivity

Area of Science:

• Food microbiology
• Bacteriophage research
• Environmental virology

Background:

• Coliphages are bacteriophages that infect Escherichia coli.
• Their presence in food products can serve as an indicator of fecal contamination.
• Understanding phage characteristics, such as temperature infectivity, is crucial for food safety assessments.

Purpose of the Study:

• To characterize coliphages isolated from various food products based on their temperature-dependent infectivity.
• To compare the isolation efficiency of different temperature-sensitive coliphage groups (High Temperature, Mid Temperature, Low Temperature) using distinct Escherichia coli host strains.

Main Methods:

• Isolation of coliphages from 38 food product samples across ten different types.
• Characterization of isolated coliphages based on their optimal reproductive temperature ranges (HT: ≥30°C, MT: 20-42°C, LT: ≤20°C).
• Comparative analysis of coliphage isolation using two different Escherichia coli host strains (E. coli C-3000 and E. coli C).

Main Results:

• Coliphages were recovered from the analyzed food samples.
• The majority of isolated coliphages were classified as High Temperature (HT) or Mid Temperature (MT) types.
• A higher percentage of HT coliphages were isolated using the E. coli C-3000 host compared to the E. coli C host.

Conclusions:

• Food products commonly harbor HT and MT coliphages.
• The choice of Escherichia coli host strain can influence the detection rates of specific coliphage types.
• These findings contribute to the understanding of coliphage ecology in food matrices and have implications for their use as microbial indicators.