## 4 Discussion
jejuni_ strains was found significantly increased in skin as compared to the one in the pectoral muscle by the qualitative method at 42 \({}^{\circ}\)C (x\({}^{2}\) = 10.6162, \(p\) = 0.004851) implying environmental contamination. _C. coli_ was the second dominant species in this study (Table 2) with 64 strains (both methods at 42 \({}^{\circ}\)C) or 63 strains (both methods at 37 \({}^{\circ}\)C). None of these strains was isolated from the visceral cavity and the liver. Most of the isolations were from the skin (x\({}^{2}\) = 5.3841, \(p\) = 0.0203) as in the case of all other _Campylobacter_ species. Interestingly, the quantitative methods at both temperatures (42 \({}^{\circ}\)C and 37 \({}^{\circ}\)C) revealed a strong positive correlation (R = 0.789, \(p\) = 0.003) to the the large size of the flock (more than 30 birds) while the qualitative methods (42 and 37 \({}^{\circ}\)C) showed a strong negative correlation (R = 0.725, \(p\) = 0.002) to the small size of the flock (3-10 birds). These differences can be attributed to the different distribution of strains according to the different analytical methods, but that these findings have in common is that the multitude of chickens in the flock plays an important role. Although _C. coli_ and _C. jejuni_ are reported to survive in the guts of various mammals as well as in other poultry species caeca, our results do not show any increased prevalence in the epidemiological groups where small ruminants and/or other poultry species were present, implying that other environmental sources of contamination like rodents or the water. _C. avium_ has been isolated from chicken and turkeys [43; 51; 52; 53; 54] yet our results do not show any increased prevalence in the groups where other poultry species shared the same environment. All four analytical methods we used, concur that the presence of small ruminants was strongly negatively correlated with its prevalence rates (R > 0.721, \(p\) < 0.002), suggesting intense antagonistic dynamics from other _Campylobacter_ strains shed by these animals. _C. lari_ was third after _C. jejuni_ and _C. coli_ prevalent species with twenty-four (24) isolated strains by three of the four methods (Table 2). This species is usually isolated from various sea birds like seagulls, from marine mammals and has been also isolated from domestic animals [55]. In our study, its isolations have been positively strongly correlated (R = 0.702, \(p\) = 0.00284) to the large size of the flock (more than 30 birds). As previously discussed for other species, the large size of the flock creates perhaps more opportunities for certain species to find niches. _C. hepaticus_ is a causative agent of Spotty Liver Syndrome (SLD), a disease of free-range laying hens [56; 57]. All birds in our study were clinically healthy and obviously, the ones from which _C. hepaticus_ was isolated were asymptomatic carriers. Most isolations occurred from liver samples. _C. hepaticus_ shows lower growth rates in iron-depleted environments and this explains its tissue tropism [58]. Regression analysis showed a strong positive correlation to the large size of the flock (more than 30 birds) and a strong negative correlation to the presence of small ruminants (R = 0.742, \(p\) = 0.00831). Six species were singletons since only one strain of them was isolated (Table 2). From these _C.unicularum_ has been isolated from rabbits [59] and probably its source in our study was rabbits kept in the same household. Since _C. rectus_, _C. helveticus_, _C. mucosalis_, and _C. shovae_ originate from humans and other animals such as dogs, cats, and pigs, while _C. hominis_ originates from humans [51], it is quite possible that the contamination of the birds in our study was either anthropogenic or coming from the household's dog or from the omnipresent cats. Anthropogenic transmission seems likely since _C. rectus_ and _C. shovae_ are involved in the pathogenesis of gingivitis and periodontitis [60; 61]. It is interesting that in _C. rectus_, _C. hominis_ and _C.