## 4 Discussion
However, all these studies refer to samples from caeca or to fecal samples where the conditions are ideal for the main thermophilic _Campylobacter_ species, and not to skin or to meat samples taken in the field as in our study [43; 44]. A most obvious observation concerning our study is that three criteria out of the four, i.e., the presence of other species of poultry (criterion B), the presence of small ruminants (criterion C), and the feeding practice (criterion D) had no effect on the prevalence and on the distribution of the overall _Campylobacter_ genus among the different epidemiological groups (Table 3). On a species level, however, some species were significantly affected by the presence of small ruminants. Criterion D (feeding practice), besides the possibility of transmission of _Campylobacter_ from the environment through animal feed to poultry farms [13] was theoretically expected to affect indirectly the general condition of the birds since the concentrates provide more nutrients than the household's leftovers of plant origin and consequently the immune system would function more efficiently keeping at bay at least some _Campylobacter_ species. However, in rural areas, the birds graze freely and acquire whatever they need from the natural environment of the estate they live, and this appears to equalize the differences in the feeding practices. As for the presence of other species of poultry, it seems that birds that share the same habitat regardless of their species, carry similar microbiomes and so the same microorganisms circulate among them. Ethology factors perhaps could limit the close contact of birds of different species creating thus a sort of intraspecies barrier. Small ruminants are a source of various _Campylobacter_ species, shedding strains in their environment [45; 46]. Possible routes of transmission are considered the pests (rodents mainly) and the personnel. Other authors however, like [PERSON] et al. (2011) propose a two-way direction of the _Campylobacter_ contamination and they report an interaction between broilers and ruminants [47]. _C. fetus_ colonizes the intestines of cattle and sheep which act as the reservoir of the microorganism [48; 49]. It is a well-known pathogen in these species causing abortion and infertility [50; 51]. Regression analysis confirmed the very strong correlation of _C. fetus_ to the presence of small ruminants among the epidemiological groups (R = 0.814, \(p\) = 0.0059), a rather expected finding. In fact, _C. fetus_ strains were only isolated from epidemiological groups where small ruminants were present in the same household as chicken. Yet in the same regression model, the large and the small number of birds were strongly negatively correlated to the number of strains of _C. fetus_, a finding implying that the size of the flock creates an ecosystem where the dynamics of antagonistic species regulate the prevalence rates of _C. fetus_. According to all four methods, 19 strains were isolated in total. Most of the isolations were from the skin and none from the visceral cavity and the liver. It is possible that this increased skin infection is due to environmental contact with small ruminants' feces. By the qualitative method at 42 \({}^{\circ}\)C distribution (Table 6), the correlation to the presence of the small ruminants was strong (R = 0.629, \(p\) = 0.012). The overall _C. jejuni_ prevalence among the different groups was very strongly positively correlated to the large size of the flock (more than 30 birds) and to the presence of small ruminants (R = 0.832, \(p\) < 0.001). _C. jejuni_ is known to colonize the digestive tract of warm-blooded hosts [48] infecting thus the poultry. Depending on the method, 96 to 98 strains were isolated making _C. jejuni_ the most prevalent of all _Campylobacter_ species (Table 2), a finding agreeing with similar findings of other authors who reported that this species is the most dominant and poultry is considered as its primary reservoir [49; 50]. The distribution of _C.