Aim: To identify potential reservoirs and transmission routes of human pathogenic Campylobacter spp. Methods and Results: An enrichment PCR method for the detection and identification of Campylobacter jejuni and/or Campylobacter coli in faecal, food and river water samples was applied to 1450 samples of 12 matrix types obtained from a defined geographical area. PCR-positive samples were cultured to yield isolates for typing, and the data for 616 C. jejuni isolates obtained. Serotyping and SmaI macrorestriction profiling using pulsed field gel electrophoresis revealed a high level of diversity within the isolates from each matrix. Campylobacter jejuni and C. coli subtypes indistinguishable from those obtained from human cases were detected in most of the matrices examined. No Campylobacter isolates were isolated from possum faeces. Conclusions: Ten of the 12 matrices examined may be involved in the transmission of human campylobacteriosis as they contained Campylobacter subtypes also isolated from clinical cases. Significance and Impact of the Study: Results indicate that, for this rural population, a range of potential transmission routes that could lead to campylobacteriosis exist. Their relative importance needs to be assessed from an exposure assessment standpoint.

This study describes a multiplex polymerase chain reaction (PCR) detection system combined with enrichment growth conditions for simultaneous detection and identification of C. jejuni, C. coli and thermotolerant Campylobacter in poultry pack rinses. The PCR primers were tested against a range of Campylobacter and non-Campylobacter species, and PCR products were only amplified from target organisms. The sensitivity of the method was similar to that obtained by conventional plating procedures, but when used in combination with the MPN method of enumeration could detect levels down to 6 MPN/100 ml of rinse. The validation of 50 samples of chicken pack rinses demonstrated the versatility of this approach in microbiological surveys to yield data for risk assessments.

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Aim:  To analyse Campylobacter jejuni typing data to define statistically which potential reservoirs and transmission sources contain isolates that are most similar to one another and to isolates from human infections. Methods and Results:  Serotyping and SmaI macrorestriction profiling data for C. jejuni isolates from human campylobacteriosis cases, chicken carcass rinses, duck, sheep, dairy and beef cattle faeces, river water, and sheep, beef and pork offal obtained from a defined rural area of New Zealand were compared using the Czekanowski proportional similarity index. Subtypes of isolates from ruminant animals, whether derived from their faeces or offals, were generally similar to one another. The spectrum of isolate subtypes from human cases was more similar to that from ruminant faeces than the other matrices considered. Isolate subtypes from chicken rinses, pork offal, water and duck faeces were not highly similar to those from other matrices. Conclusions:  Results from a combination of phenotypic and genotypic approaches suggest that, for this rural population, exposures associated with a rural lifestyle may be significant sources of human campylobacteriosis. Significance and Impact of the Study:  The Czekanowski index was applied to subtyping data and supported the greater importance of contact with livestock in campylobacteriosis cases associated with a rural setting, in comparison with urban studies that have identified poultry‐related factors.

Aims: To characterize the bacterial composition of mallard duck faeces and determine if novel bacterial species are present that could be utilized as potential indicators of avian faecal contamination. Methods and Results: Combined samples of fresh faeces from four ducks were serially diluted and plated onto six different media selected to allow the growth of a range of organisms at 42°C under three atmospheric conditions: aerobic, microaerophilic and anaerobic. Forty-seven morphologically dissimilar isolates were purified and partial sequencing of the16S rRNA indicated at least 31 bacterial species. Twenty of these could be identified to the species level including pathogenic species of Bacillus, Campylobacter, Clostridium and Streptococcus. Other species identified included: Enterococcus, Escherichia, Megamonas, Cellulosimicrobium, Neisseria, Staphylococcus and Veillonella. Potentially novel species, which could represent bacteria specific to avian fauna included Bacillus, Corynebacterium, Macrococcus and Peptostreptococcus, while four isolates had <97% similarity to known bacterial species in the available databases. Conclusion: A survey of the natural microflora of the mallard duck and its hybrid with the grey duck identified both bacteria that are potentially human pathogenic and putative novel bacteria species as determined by 16S rRNA sequencing. Significance and Impact of the Study: This study provides further evidence that duck faeces is a potential human health hazard, and has identified bacteria potentially useful for distinguishing duck faeces from other faecal sources.