Microorganismos aislados en cultivo bacteriológico de muestras de leche de vacas holstein clínicamente sanas

Abstract

Amicrobiological analysis was performed to determine the frequency of isolationof microorganisms of infectious and environmental type in milk from agroup of clinically healthy cows in two different types of milking (manual andmechanical). To each sample of milk was made bacteriological culture todetermine the presence of microorganisms. Of 289 milk samples evaluated,193 (66.78%) were positive for isolation of any type of pathogen, of which 81(28.02%) samples came from manual milking and 112 (38.75%) belonged tomechanical milking, finding a higher percentage of isolation of bacterial pathogensin milks coming from mechanical milking system (p = 0.0236). Themost isolated pathogen was the Arcanobacterium haemolyticum, A microorganismthat forms part of the saprophytic flora of the animal, with an individualpresence in 20.14% and in coinfection with other pathogens in 0.7%of the samples. The most common microorganism of subclinical mastitis incattle is Streptococcus agalactiae, which in the present study was isolatedfrom 12.50% of milk samples. The odds ratio (OR) between the isolation ofStreptococcus agalactiae and the Somatic Cell Score (SCS) was determined,which was statistically significant, indicating that when this pathogen is presentthe SCS increases and the animals are more susceptible to mastitis.