Bu çalısmada toplam 211 çig süt örneginde Yersinia enterocolitica ve Listeria monocytogenes varlıgı arastırılmıstır. Örneklerden 8(%3.79) Y. enterocolitica, 6(%2.83) Y. enterocolitica benzeri mikroorganizma olmak üzere toplam 14 sus izole edilmistir. Y. enterocolitica benzeri mikroorganizmaların 3’ü (%1.4) Y. kristensenii, 2’si (%0.94) Y. frederiksenii, 1’ide (%0.47) Y. intermedia olarak teshis edilmistir. Arastırmada aynı çig sütlerden 2(%0.94) L. monocytogenes izolasyonu da gerçeklestirilmistir. Y. enterocolitica ve benzeri mikroorganizmaların mevsimsel dagılımları degerlendirildiginde bu mikroorganizmaların düsük sıcaklıklarda üremeyi sevdigi gözlenmistir. Izolasyonların 6’sı (%42.85) kıs mevsiminde, 5’i (%35.71) ilkbaharda, 3’ü (%21.42) yaz mevsiminde gerçeklestirilmistir. L. monocytogenes izolasyonununun 1’si kıs, digeride ilkbahar mevsiminde tespit edilmistir. L. monocytogenes, Y. enterocolitica ve benzerlerinin izolasyonlarının dagılımları incelendiginde Ankara ve çevresinden saglanan örneklerde daha fazla oldugu belirlenmistir.

The presence of Yersinia entrocolitica and L. monocytogenes in total 211 raw milk samples were investigated. In this study a total number of 14 Y. enterocolitica and Y. enterocolitica like microorganism have been isolated. 3.79% (8 samples) of the total isolation were characterized as Y. enterocolitica whereas 2.83% (6 samples) of these were found to be Y. enterocolitica like microorganism. 1.4% of the total Y. enterocolitica like microorganism (3 samples) were identified as Y. kristensenii, 0.94% (2 samples) of the total Y. enterocolitica like microorganism identified as Y. frederiksenii and 0.47% (1 samples) of the total. Y. enterocolitica like microorganism identified as Y. intermedia. A total of 0.94% (2 samples) L. monocytogenes were isolated in the same raw milk samples. Y. enterocolitica and like these microorganisms were observed to grow very easly in low temperature in according to seasonal distribution. 42.85% (6 samples) of total isolations were made during winter time, 35.71% (5 samples) of total isolations were made during spring time, 21.42% (3 samples) of total isolations were made during summer time. One of the L. monocytogenes was isolated in winter whereas the other one was isolated in spring season. When the isolation of L. monocytogenes, Y. enterocolitica and Y. enterocolitica like microorganism were investigated according to the places where raw milks are taken; it was detected that the isolation had been done in Ankara and its around.