Comparison of the isolation and inhibition abilities of selective media used for Brucella spp. Isolation

Abstract

The aim of this study was to compare and contrast the isolation ability of selective media developed for Brucella spp. isolation and their inhibition ability against contaminant microorganisms. Fifty-one field strains biotyped from abortion case samples and 25 Brucella spp. negative organ samples were used. Strain suspensions and organ suspensions were prepared separately. The turbidity of the strain suspensions was measured via spectrophotometer. The bacterial density of the strain suspensions was prepared in such a way that the suspensions would have different turbidity values. Inoculation into Farrell, Agrifood Research and Technology Center of Aragon, Jones & Morgan, and Modified Thayer Martin media was performed simultaneously from a dilution of each strain suspension and organ suspension. It was incubated in a 37 degrees C, 5%-10% CO2 condition for 5-8 days. Brucella isolates were identified via a conventional biotyping method. The results of this study illustrate that selective media have isolation and cultivation ability for B. abortus biovar (bv) 3, B. abortus bv1, B. melitensis bv3, B. melitensis bv1, Rev1, and S-19 strains isolated from the field. There is more variation in the contaminant inhibition ability of the media compared to their isolation sensitivity. Farrell medium has 47 Brucella spp. isolations in 51 samples. It showed the highest performance with an isolation sensitivity of 92.1% and an inhibition ability of 80%. In this context, it might be suggested that researchers should initially use Farrell medium and, afterwards, use it simultaneously with another medium to be able to increase the isolation ability.