Lack of evidence for Mycoplasma spp. in bulk tank milk of herds located in mid-western Colombia

Abstract

Mycoplasma spp. is reported as a highly contagious mastitis-causing bacteria in dairy cattle, without successful or low response to most common antibiotic treatments due to the lack of cell wall. In Colombia it has been reported in the Central Andean region during 2014. The aim was to estimate the prevalence of Mycoplasma spp. in bulk tank milk using microbiological and molecular diagnosis. A random longitudinal study en­rolling 220 commercial dairy farms located in four provinces of the mid-western region of Colombia from four pasteurizer companies was performed. Bulk tank milk samples were collected once monthly for three months period for determining somatic cell count (SCC) and microbiological and molecular diagnosis of Mycoplasma spp. cultures were done without pre-enrichment procedures directly in mycoplasma agar with cefoperazone to inhibit growth of opportunistic microorganisms, plates were incubated under 37° C and atmosphere of 10% CO2 and inspected during a 10d period. Molecular analysis was done by a multiplex PCR using specific primers targeting the 16S-23S rARN gene of Mycoplasma spp. and from non-pathogenic bacteria occasionally found in milk. LnSCC average of included dairy farms was 6.19 x103 cells/mL, Mycoplasma spp. was not isolated during microbiological cultures, and no DNA belonging to the species was detected by PCR in the 220 bulk tanks milk, with an estimated prevalence lower than 2.3%. This finding shows that there is not microbiological or molecular evidence that demonstrates the presence of the pathogen in the milk from the mid-western region of Colombia at herd level.