Survival of Campylobacter jejuni in potable water biofilms: a comparative study with different detection methods

Campylobacteria are important foodborne pathogens. C. jejuni bacteria have caused several drinking water-related epidemics in Finland. Normally, C. jejuni is not able to multiply in drinking water or in biofilms although it may survive in biofilms. The survival of C. jejuni in biofilms was studied using the Propella biofilm reactor. The number of bacteria was analysed with traditional culture methods and with fluorescence in situ hybridisation (FISH). By culture methods C. jejuni was detectable for only 1 d after spiking whereas bacteria were found from biofilms for at least 1 week after spiking and from outlet water of the reactor for 3 weeks when using FISH. These results suggested that C. jejuni may survive in biofilms and culture methods probably seriously underestimate the real number in water and in biofilms.