Sastav mikroflore sirovog kravljeg mlijeka i identifikacija enterokoka primjenom MAL DI-TOF MS - kratko priopćenje.

Raw milk consumption could present a potential risk for public health due to the presence of foodborne pathogens and spoilage bacteria. In this research, microbiota or raw cow’s milk was studied with particular reference to the presence of enterococcal opportunistic pathogens. Total viable count, psychrophilic bacteria, lactic acid bacteria, staphylococci, Escherichia coli, enterococci, enterobacteria, Listeria spp. and sulfitereducing clostridia were evaluated using standard culture methods. Milk samples originated from healthy (n = 17) and antibiotic-treated cow’s udders (n = 19). Presumptive enterococci (n = 43) were randomly selected from chromogenic media and subjected to phenotypic identification by API 20 Strep, followed by Matrix- Assisted Laser Desorption Ionization - Time of Flight Mass Spectometry (MALDI-TOF MS). Statistically significant differences (P<0.05) regarding the udder status were found in the total viable count and lactic acid bacteria. MALDI-TOF MS determination showed 100% concordance with API 20 Strep in the identification of Enterococcus faecalis. Strains determined to the genus level only, or non-determined strains by API 20 Strep were successfully identified using MALDI-TOF MS to the strain level as E. faecalis, E. faecium and E. durans. Results showed that MALDI-TOF MS could be applied as a reliable method in the routine identification of enterococcal species from raw milk.Konzumiranje sirovog mlijeka može predstavljati potencijalni rizik za potrošače uslijed prisutnosti patogenih bakterija i bakterija kvarenja. U ovom radu istražen je sastav mikroflore sirovog kravljeg mlijeka s posebnim naglaskom na prisutnost enterokoka. Određivan je ukupni broj bakterija, psihrofilnih bakterija, bakterija mliječne kiseline, stafilokoka, Escherichia coli, enterokoka, enterobakterija, Listeria spp. i sulfitreducirajućih klostridija primjenom standardnih mikrobioloških metoda. Mlijeko je potjecalo od zdravih krava (n = 17) i krava s liječenim mastitisom (n = 19). Kolonije enterokoka (n = 43) su nasumično odabrane sa selektivne podloge te podvrgnute fenotipskoj identifikaciji pomoću API 20 Strep, a potom MALDI-TOF masenom spektrometrijom. Statistički značajne razlike (P