I am not sure what you really want. We often observe resistance in veterinary isolates to erythromycin as it is the parent molecule for the veterinary products: tylosin and tilmicosin. The tetracyclines are in commonly used in animals and resistance does build-up quickly as it is usually found in resistance plasmids. However, tetracylines are not traditional treatments for mastitis caused by S. agalactiae. Therefore you should also test the beta-lactam drugs i.e. penicillin G (to represent it and the stabilized penicillins such as procaine penicillin) and any cephalosporins (note that ceftiofur can only be administered as an intra-mammary preparation as it does not distribute well to the udder when injected. Note that resistance more commonly develops when too low a dose or expired products are administered for prolonged periods of time.

thanks jackie picard

1-i want to know are you think present resistance antibiotic genes in streptococcus agalactiae ?

2- i will make sensitive test for five common antibiotic Iraq are tetracycline , procaine penicillin G , neomycin , erthromycine , that common use in Iraq

3- i will select more resistance antibiotic gene and diagnosis gen by PCR

4- are you have any suggest on that project.

i will be appreciate for you