Sample No. Samples No. Positive Samples Full-fat milk powder 15 0 Skimmed

milk powder 37 5 Dried whey 5 0 Dried ice-cream 5 0 Dried artificial cream 5 0 Sahlab 10 4 Infant milk formulas 35 2 Environmental, Milk Factory 1 1 Stored Domiatti cheese 10 0 Fresh Domiatti cheese 10 4 Ras cheese 10 0 Kariesh cheese JAK activation 10 0 Total 152 16 Presumptive positive isolates producing blue-green colonies were identified using Rapid ID 32E test galleries (bioMérieux Ref: 32700, France) as per the manufacturer’s instructions. Isolates identified as Cronobacter (E. sakazakii) were confirmed using a modified Trichostatin A cost version of the real-time PCR method described by Seo and Brackett [16]. In short, a primer set and probe targeting the dnaG gene located internally to the macromolecular synthesis (MMS) operon was applied [17]. The Cronobacter genus currently consists of six genomospecies

[18]. To this end, isolates confirmed as Cronobacter were speciated using biochemical differentiation tests as described by Iversen et al. [19] and recN gene sequence analysis (Kuhnert P., Korczak B.M., Stephan R., Joosten H., Iversen C: click here Phylogeny and whole genome DNA-DNA similarity of Enterobacter and related taxa by multilocus sequence analysis (MLSA)). Antibiotic Susceptibility Testing Cronobacter isolates were tested for their susceptibility to ampicillin (10 μg), compound sulphonamides (300 μg), furazolidone (15 μg), gentamicin (10 μg), neomycin (30 μg), spectinomycin (100 μg), streptomycin (10 μg), and trimethoprim (5 μg) using the Kirby-Bauer disc diffusion method [20]. Antibiotic disks were obtained from Oxoid, Hampshire, UK. Molecular Subtyping Pulsed-field gel electrophoresis (PFGE) was applied as described previously [21]. Analysis was carried out using BioNumerics software V3.0 (Applied Maths, Sint-Martens-Latem, Belgium). A dendrogram was generated using the DICE coefficient and unweighted pair group method with arithmetic GBA3 mean (UPGMA). A band tolerance and optimization coefficient of 1.5% was applied. Repetitive sequence-based (rep-PCR) amplification was performed using an automated rep-PCR system as previously described [22]. Analysis

was performed using Diversilab® software V3.3 (Diversilab®, bioMérieux, France). Isolate similarity was calculated using the Pearson Correlation (PC) coefficient. recN Gene Sequencing recN gene sequencing was performed by Fasteris SA (Plan-les-Ouates, Switzerland) using a modified version of the method described by Kuhnert et al. (Kuhnert P., Korczak B.M., Stephan R., Joosten H., Iversen C: Phylogeny and whole genome DNA-DNA similarity of Enterobacter and related taxa by multilocus sequence analysis (MLSA)). PCR reactions were carried out in 3 × 15 μl volume, which were then pooled together. The thermo cycling conditions employed were as follows: 95°C for 3 min, followed by 30 cycles comprising 95°C for 30 s, 54°C for 30 s and 72°C for 2 min. A final extension of 72°C for 5 min was applied.