RELATIONSHIP BETWEEN THE TYPES OF BACTERIA ISOLATED FROM POSTPARTUM UTERI AND THE CELL-MEDIATED IMMUNITY IN DAIRY COWS

Abstract

The main aim of the present study was to evaluate the relationship between the isolated bacteria from the uterus and the immune status of dairy cows during the postpartum period. Uterine swabs were collected from 41 Holstein-Friesian cows with normal calving and 5 cows with retained fetal membranes (RFM) at 7-11 days, 17-25 days and 27-38 days postpartum. After swabbing, blood samples were collected from tail veins of 34 cows at 7-11 days, 30 cows at 17-25 days and 29 at 27-38 days postpartum for carrying out lymphocyte stimulation test. The collected swabs were cultured and the isolated bacteria were categorized according their expected pathogenic potential within the uterus into: pathogenic, less pathogenic and non-pathogenic bacteria. During the examined postpartum periods, a total of 108 uterine swabs were collected from 46 cows. With the exception of a swab from a cow with normal calving at 17-25 days postpartum, all the uterine swabs were bacteriologically positive. One hundred-sixty five and 23 isolates were recovered from cows with normal calving and cows with RFM, respectively during the examined postpartum periods. The isolated less pathogenic bacteria were Enterococcus spp. and Histophilus somni, pathogenic were Trueperella (T.) (Arcanobacterium) pyogenes and Escherichia (E.) coli and non pathogenic were Bacillus subtilis, Corynebacterium spp., Pseudomonas (P.) aeruginosa, Proteus spp., Bacillus spp., Micrococcus spp.and Streptococcus spp. Regarding the results of lymphocytes stimulation test, 57% of cows were healthy and 37.6% were healthy with lower immunosuppression. On the other hand, low percentage of cows (5.4%) was immunosuppressed. Of 159 bacterial isolates, 90 (57%) were isolated from healthy cows, 62 (39%) from lower immunosuppressed cows and 7 (4 %) from immunosuppressed. Of 46 pathogenic bacterial isolates, 28 (61%) were isolated from healthy cows and 18 (39%) from lower immunosuppressed cows. Of 89 less pathogenic bacterial isolates, 49 (55 %) were isolated from immunohealthy cows, 34 (38 %) from lower immunosuppressed and 6 (7%) from immunosuppressed. Of 24 non pathogenic isolates, 13 (54%) were isolated from healthy cows, 10 (42%) from lower immunosuppressed and 1 (4%) from immunosuppressed. In conclusion, the presence of pathogenic and less pathogenic bacteria might stimulate the cellular immune response in dairy cows during the postpartum period.