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Rapid detection of temperate bacteriophage using a simple motility assay
Yunxue Guo1,2,3, Jianzhong Lin1,3, Xiaoxue Wang1,2,3
1Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No.1119, Haibin Road, Nansha District, Guangzhou, 511458, China.
Abstract:
Phage contamination is a common complication for the fermentation and pharmaceutical industries. The risk of bacteriophage contamination in laboratory processes increases with multiple rounds of genetic manipulation such as deletion and complementation. The contamination of temperate phages does not lead to immediate host cell lysis but could become a serious issue when the lytic cycle is activated under specific conditions. Our objective was to develop a quick and reliable detection method for checking possible temperate phage contamination. Here, using motility plates, we found that when the strain carries a newly acquired temperate phage, its presence can be easily detected by the formation of a clear 'lysis zone' when swimming against the original strain on the same swimming plates. Compared to the traditional double agar layer method and genomic sequencing-based methods, the duration of the motility-based assay is shorter and the procedure is simplified. More importantly, for the bacterial strains that already contain active prophages, this method can still easily detect the newly acquired phages without tedious phage identification procedure. These features make this method highly applicable to laboratory and industrial processes.
Insights
A new motility plate assay quickly detects temperate phage contamination in industrial and lab settings. This method simplifies phage detection, even in strains with existing prophages, preventing costly contamination issues.
Area of Science:
- Microbiology
- Industrial Biotechnology
- Pharmaceutical Science
Background:
- Bacteriophage contamination poses a significant risk in fermentation and pharmaceutical production.
- Temperate phage contamination, while not causing immediate lysis, can activate lytic cycles under specific conditions.
- Genetic manipulation processes can increase the likelihood of phage contamination in laboratory strains.
Purpose of the Study:
- To develop a rapid and dependable method for detecting temperate phage contamination.
- To provide a simplified assay applicable to both laboratory and industrial settings.
Main Methods:
- Utilized motility plates to detect temperate phage presence.
- Assayed for the formation of a clear 'lysis zone' when a phage-carrying strain swims against the original strain.
- Compared the motility-based assay with traditional double agar layer and genomic sequencing methods.
Main Results:
- The motility-based assay successfully detected newly acquired temperate phages by observing lysis zones.
- This method proved significantly faster and simpler than conventional techniques.
- The assay effectively identified new phages even in bacterial strains already harboring active prophages.
Conclusions:
- The motility plate assay offers a quick, reliable, and simplified approach for temperate phage detection.
- This method is highly suitable for routine monitoring in laboratory and industrial fermentation processes.
- The assay's ability to detect new phages without complex identification procedures enhances its practical applicability.
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