Coastal water bacteriophages infect various sets of sequence types.

INTRODUCTION

Gastrointestinal illnesses associated with the consumption of shellfish contaminated with have a negative impact on the shellfish industry due to recalls and loss of consumer confidence in products. This bacterial pathogen is very diverse and specific sequence types (STs), ST631 and ST36, have emerged as prevalent causes of foodborne disease outbreaks in the US, though other STs have been implicated in sporadic cases. We investigated whether bacteriophages could be used as a proxy to monitor for the presence of distinct STs in coastal waters.

METHODS

For this purpose, bacteriophages infecting were isolated from water samples collected on the Northeast Atlantic coast. The isolated phages were tested against a collection of 29 isolates representing 18 STs, including six clonal complexes (CC). Four distinct phages were identified based on their ability to infect different sets of isolates.

RESULTS AND DISCUSSION

Overall, the 29 bacterial isolates segregated into one of eight patterns of susceptibility, ranging from resistance to all four phages to susceptibility to any number of phages. STs represented by more than one bacterial isolate segregated within the same pattern of susceptibility except for one ST. Other patterns of susceptibility included exclusively clinical isolates represented by distinct STs. Overall, this study suggests that phages populating coastal waters could be exploited to monitor for the presence of STs known to cause foodborne outbreaks.