The present study describes a flow cytometry-based method, which can detect and distinguish Gram-negative and Gram-positive bacteria in mastitis milk samples. The differentiation was based on bacterial fluorescence intensities upon labeling with biotin-conjugated wheat germ agglutinin and acridine orange. Gram-negative bacteria in milk samples were detected with a sensitivity of 1 and a specificity of 0.74, when classification was based on previously established cut-off values. However, reducing the cut-off values could result in a sensitivity and specificity of 1. This flow cytometry-based technique could potentially provide dairy farmers and attending veterinarians with on-site information on bacterial Gram-type and could prevent ineffective antimicrobial treatment in mastitis cases caused by Gram-negative bacteria.
Source: Langerhuus et al. – Journal of Dairy Science, 96, 267-277, 2013
Complete abstract: www.m²-magazine/org > 027-25.02.201