## 3 Isolation of _Campylobacter_ spp. ### Detection and/or Enumeration Procedure  
The choice of microbiological method that can be used to isolate campylobacters from a food commodity can significantly affect the prevalence or even the estimated concentration of the pathogen in food [60; 73; 96; 97; 98; 99; 100; 101; 102], and therefore, the distribution of different _Campylobacter_ species recovered from food during the microorganism's detection or enumeration procedure followed. _C. jejuni_ was mainly isolated during pathogen enumeration procedure, while _C. coli_ was the predominant species recovered from all plating culture media following enrichment in Bolton broth during the detection of _Campylobacter_ in chicken meat [60; 63]. The possibility of combining different enrichment broth (e.g., Bolton broth or Preston broth) with different selective and/or differential (i.e., chromogenic) solid culture media (i.e., agars) (e.g., modified charcoal-ceforezzone-deoxycholate agar; mCCDA, Preston agar) could be utilized as an alternative to the standard ISO 10272-1 protocol [103] used for the detection of _Campylobacter_ in food [104; 105; 106]. For pathogen enumeration, different agars than mCCDA proposed by ISO 10272-2 enumeration method [107], either selective (e.g., Preston agar or Karmali agar) or chromogenic (e.g., Campylobacter selective agar; CASA(r), Brilliance(tm)Campy count agar, BCCA) which have been found to perform equally well to the recommended mCCDA in enumerating colonies of _Camylobacter_ spp. [63; 98; 108; 109; 110; 111; 112], could be used after the initial dilution of the food sample. After all, the colored colonies of _Camylobacter_ on chromogenic agars are easier to record and count than those on charcoal-based agars, such as mCCDA. Enrichment of chicken meat samples in Preston broth for 24 h followed by plating on mCCDA performed better than 48 h enrichment in Bolton broth and plating on mCCDA [98], while this alternative enrichment and plating combination was taken into account in the revised ISO method for _Camylobacter_ spp. detection (i.e., procedure B in the ISO 10272-1 protocol) [103]. Furthermore, the parallel use of the detection and enumeration procedures improves the recovery of _Camylobacter_ spp., whereas chromogenic agars, like CASA and BCCA, should be considered as secondary plating media for simultaneous or optional use together with the ISO-recommended mCCDA and/or even as suitable alternatives to the latter selective agar [63]. In any case, it has been proved that the previously mentioned enrichment and/or plating alternatives can significantly affect the recovery of _Camylobacter_ strains from food [60; 73; 96; 97; 98; 99; 100; 101; 102]. Composition of Culture Media for Detection/Enumeration  
In food samples with an expected low number of _Camylobacter_ spp. and low concentration levels of accompanying (background) microbiota and/or stressed campylobacters (e.g., cooked or frozen samples), the enrichment in Bolton broth is highly recommended for pathogen detection, whereas for samples with high concentration levels of background microbiota other than _Camylobacter_ spp. (e.g., raw meats including poultry or raw milk), the use of Preston broth as a sample enrichment medium is suggested [98; 103]. The reduced recovery of campylobacters from raw chicken meat after sample enrichment in Bolton broth compared to direct plating from the initial dilution of the food sample is likely attributable to the presence of cefoperazone in the liquid medium. The latter is a third generation \(\beta\)-lactam antibiotic which is supplemented into Bolton enrichment broth, as well as in mCCDA plates utilized for pathogen isolation. Foods containing microbiota resistant to third generation \(\beta\)-lactams, including cefoperazone, such as raw chicken containing \(\beta\)-lactam-degrading _E. coli_, namely extended-spectrum \(\beta\)-lactamase-producing; ESBL-producing _E.