Occurrence of abortive infection systems and phage resistance in lactic acid bacteria isolated from bryndza ewes' cheese

摘要

Sixty-eight bacterial isolates of lactococci, lactobacili and enterococci obtained from bryndza ewes' cheese were identified using Matrix-assisted laser desorption ionization-time of flight (MALDI TOF) analysis of protein spectra. All lactococcal isolates from bryndza were identified as Lactococcus lactis. Lactobacillus plantanim was found to be a dominant species among lactobacilli, followed by Lb. paracasei. Enterococcal population of bryndza cheese consisted mainly of Enterobacter faecium, followed by E. durans and E. faecalis. The presence of genes encoding for 23 abortive infection systems (Abi) in the isolates was tested by polymerase chain reaction analysis. Eleven out of 24 Lc. lactis isolates possessed AbiB system. No Abi system was detected in Lactobacillus spp. AbiC, AbiD, AbiEi and Abil were found in enterococcal isolates. In parallel experiments, all isolates were tested for sensitivity to bacteriophage infection. No clear correlation was found between the presence of abortive infection systems and resistance against bacteriophages.