## 1 Introduction  
_Salmonella_ spp. are the most prevalent species of pathogens implicated in food-borne infections [1, 2]. Thus, their monitoring and control in animals across the EU is a priority. Pigs are an important source of human infection with _Salmonella_ spp. [3, 4],hence, pig farms are targets for the control of the pathogen. Its effective control depends on the accurate estimation of _Salmonella_ prevalence in a pig population, which depends on the sampling plans, sample points (surfaces of the slaughterhouse or part of the pork tested for presence of _Salmonella_), and number of grams/surface area tested; thus, isolation of the agent [5, 6] uses a combination of culture media. Some of them are, due to their selectivity and sensitivity, the 'gold standard' for _Salmonella_ isolation. However, for ensuring protection of the public, a combination of methods is recommended by accreditation bodies and regulatory authorities, such as the International Standards Organization (ISO). _Salmonella_ spp. are a genus requiring more techniques and methods for isolation and identification of its members than most other agents of public health importance [7]. The complexity of the investigation of animal salmonellosis demanded a universally applied methodology for the isolation of _Salmonella_ spp. from animals and their products across the EU. This methodology is described in EN-ISO 6579-1:2017 [8], which has become the reference method for assessing the prevalence of _Salmonella_ spp. infection in fattening and breeding pigs [9; 10; 11]. The EN-ISO 6579 has been found to perform better than commercial polymerase chain reaction (PCR), the BAX method (a real time PCR assay,) and three other commercially available systems based on enzyme-linked immunosorbent assay [12]. The use of this ISO, although expensive and laborious, is considered a 100% specific method when used in combination with serotyping [13]. As a universally used method, it also helps the comparison of results across the EU and thus the coordination of control programs undertaken in various member states. The newer version, ISO 6579-1:2017, provides guidance for primary sampling methods and the preparation of samples before isolation, but also for strain identification for a detailed epidemiological investigation. _Salmonella_ spp. are isolated after pre-enrichment in buffered peptone water (BPW), resuscitating sub-lethally damaged or slow-growing _Salmonella_ cells, thus minimizing false-negative results. Pre-enrichment also helps the pathogen to survive the toxic effects of selective enrichment media [14; 15] when it is present in very low numbers, as is the case with asymptomatic animals. However, pre-enrichment may not help with isolation from feces of the less vigorous _Salmonella_ strains, such as the host-adapted ones. The problem in this case is the overgrowth of competing bacteria species multiplying faster than slow-growing _Salmonella_ during non-selective pre-enrichment [16]. When such a case is suspected, enrichment on modified semi-solid Rappaport-Vassiliadis (MSRV) medium supplemented with novobiocin is recommended. MSRV medium supplemented with novobiocin inhibits the growth of most Gram-positive and negative bacteria, helping with the growth of less vigorous _Salmonella_ spp. The introduction of this medium improved recovery compared to previously used selective enrichment brotts, such as Rappaport-Vassiliadis (soya base) (RVS) broth [17]. In addition, direct visualization of cultures minimizes time and material for confirming a definite negative result [18; 19; 20; 21]. In all other cases, pre-enrichment is followed by enrichment using selective plating on xylose-lysine-deoxycholate (XLD) agar and is supplemented by an additional agar medium of choice, which enhances the differentiation of salmonellae from other enterobacteria.