Extended Survival and Persistence of Campylobacter spp. in Water and Aquatic Biofilms and Their Detection by Immunofluorescent-Antibody and -rRNA Staining

Abstract

In water microcosm experiments, the survival times ofCampylobacter isolates differed by up to twofold, as determined by culturing; this difference increased to fourfold when particular combinations of temperature and oxygenation were used. The mean survival times were much longer at 4 and 10°C (202 and 176 h, respectively) than at 22 and 37°C (43 and 22 h, respectively). The influence of anaerobiosis on survival time was less dramatic and differed considerably between isolates. In a two-stage water distribution model preparation containing a biofilm consisting of standardized autochthonous water microflora, Campylobacterisolates continued to differ in survival time. However, the survival times of cultures were considerably longer in the presence of the autochthonous water microflora (strains CH1 and 9752 survived 700 and 360 h, respectively, at 4°C) than in the sterile microcosms (strains CH1 and 9752 survived 230 and 157 h, respectively). Although increased temperature and oxygenation were generally detrimental to culturability, the interaction of these two factors influenced the two strains examined differently. When the organisms were grown aerobically at 30°C, the survival of the two strains was reversed; aerobiosis decreased the survival time of strain CH1 by 30%, but unexpectedly improved the persistence time of strain 9752 by more than threefold. Persistence times within biofilms were much longer when they were determined by detection methods not involving culturing. Immunofluorescent-antibody staining demonstrated that the pathogen persisted up to the termination of the experiments after 28 and 42 days of incubation at 30 and 4°C, respectively. The specificity of detection within intact biofilms was reduced because of high background fluorescence. However, preliminary studies with aCampylobacter-specific rRNA probe revealed the same extended persistence of the pathogen within the biofilms.

Role of environmental survival in transmission ofCampylobacter jejuni

“…There have been a number of studies aimed at determining the survival of Campylobacter in laboratory model systems representing environmental niches. For example, it has been shown that different Campylobacter isolates vary in their ability to survive in water microcosms (Buswell et al, 1998). Survival in water was temperaturedependent, with Campylobacter generally surviving much better at low temperatures (10-16°C) compared with room temperature.…”

Environmental survival mechanisms of the foodborne pathogen Campylobacter jejuni

“…However, Campylobacter spp. have been reported to survive in water, at low temperatures, for up to 4 months (Rollins and Colwell 1986;Buswell et al 1998;Hazeleger et al 1998), during processing (Cools et al 2005) and in the environment generally (Park 2002). Therefore, survival mechanisms other than those commonly found in other organisms (like two-component regulators) may be important.…”

“…can form biofilms in aquatic environments, on stainless steel and on glass (Somers et al 1994;Buswell et al 1998). The microenvironment created within the biofilm may protect the C. jejuni cells from oxygen inactivation, considering the survival of C. jejuni for 1 week at 10°C in low-nutrient media and in normal atmospheric conditions, despite its susceptibility to this stress (Rollins and Colwell 1986;Buswell et al 1998). Trachoo et al (2002) reported enhanced survival of C. jejuni during incubation at 12 and 23°C over a 7-day period.…”

Survival of Campylobacter jejuni and Escherichia coli in groundwater during prolonged starvation at low temperatures

“…Survival was significantly lower in the LR microcosm which had a DOC similar to that of HR. This kind of variability in the survival of C. jejuni is not uncommon, and has been associated with differences between C. jejuni strains, initial culture conditions, growth temperature, pH and oxygenation (Buswell et al 1998;Federighi et al 1998;Lazaro et al 1999;Cools et al 2003). In this study, a single strain of C. jejuni was used, and inoculum preparation (wash and resuspension in PBS) and incubation (in the dark at 4°C) conditions were all held constant.…”

“…Cools et al (2003) found that starved C. jejuni lost culturability more quickly on selective media, and that resuscitation was also influenced by the media type. In fact, when incubated at low temperatures (4-6°C), C. jejuni is shown to become nonculturable weeks or even months before other measures of viability decrease or disappear (Terzieva and McFeters 1991;Buswell et al 1998;Lazaro et al 1999;Thomas et al 1999). This maintenance strategy ensures the survival of some minimal portion of the population for passage to a new host when opportunity presents.…”