## 4 Discussion
However, a further correlation between the phenotypical and the genotypical resistance as well as hierarchical cluster analysis it is doubtful if they could shed light on the origins of these genes, given the remoteness of most of these farms and the scarcity of the isolates. The genus _Staphylococcus_ consists of 47 species and 23 subspecies. Of these, 38 species belong to the Coagulase Negative Staphylococcus (CNS) group. Additionally, newer reports state 53 species and 28 subspecies (www.bacterio.net (accessed on 2 December 2021) [61; 62]) with the same number of CNS species. Although CNS species form a group, this group is not based on phylogenetic relationships but is rather defined by delimitation from the coagulase positive _Staphylococci_ such as _S. aureus_[63]. There is a consensus among most authors that CNS are the major causative agent of subclinical mastitis (SCM), and they report various prevalence rates which variate from 4.0% to 50% [13; 64; 65; 66; 67; 68; 69; 70; 71]. Their high prevalence is due to the subclinical character of the mastitis because they often go undetected [72; 73]. CNS are present in the milking environment, on tools or on equipment, on the surface of the teat and on the hands of the personnel of the farm and cause infectious inflammation through the teat canal. The result of such an infection is mastitis characterized by increased SCC, reduction of milk yield, compromised lamb development, spontaneous abortions, and high mortality [74]. They form biofilms which act as barriers to the penetration of antibiotics and behave as a hazard to the action of phagocytes [63; 69; 75; 76; 77]. Not all CNS infections lead to inflammation and the outcome depends on the condition of the skin and of the mucous membranes as barriers to the infiltration of the bacteria. The immune system of the host is also an important parameter since the presence of the leucocytes is imperative for phagocytosis [78]. CNS often carry multiple pathogenic factors such as enterotoxins and toxic shock syndrome toxin -1 (TSST-1) which are located on mobile genetic elements and can be horizontally transferred to other strains and populations [79]. [PERSON] et al. (2006) [80] isolated _S. epidermidis_ and _S. chromogenes_ from raw milk and from the skin of the farmers who milked the animals. The fact that the isolation of these microorganisms is more frequent from the hands than from the milk lead the authors to the conclusion that humans are a major source of infection of animals during milking. _5. epidermidis_ is the dominant CNS species in subclinical mastitis [71; 81]. [PERSON] et al. (2010) regard _S. caprae_ along with _S. epidermidis_ to be the most common CNS species in sheep milk [82]. CNS infection of the udder results also to technological problems in cheese making due to increased protein loss through whey [83; 84; 85]. The casein is lost in increased quantities in the whey because it has been already degraded in the mammary gland. If the proportion of milk from infected animals is high in the bulk tank, then the increased losses of protein and fat lead to formation of cheese with softer and more elastic texture due to the higher water content [70]. Subclinical mastitis reduces the lactose level of the milk causing impaired coagulation [86; 87; 88; 89; 90]. Despite these conclusions, it seems that not all CNS are technologically detrimental. [PERSON] et al. (2020) [91] recognize the CNS as beneficial bacteria contributing to the ripening or to the fermentation of meat products and while they exert protection against spoilage bacteria through the production of bacteriocin-like metabolites. In the present study group B had significantly higher CNS counts in the bulk tank milk than group A (Mann-Whitney U = 5, \(p\) = 0.0455) while the SCC counts were at the same level between the groups (\(p\) = 0.93624). These findings suggest that the increased counts of CNS in group B are not associated with severe inflammation.