Isolation, identification and drug resistance analysis of a yak-derived Mannheimia haemolytica from Nagqu City

In order to explore the main cause of the disease in a yak farm in Nagqu City, 10 nasal swabs from the sick yak in the farm aseptically were collected in this experiment, and the collected nasal swabs were conducted for bacteria isolation, culture, identification, and separated bacteria were tested for drug sensitivity. The results showed that the isolated and purified bacteria was Gram-negative brevibacterium; biochemical test identified it as Mannheimia haemolytica. The sequencing results were compared with other Mannheimia haemolytica in GenBank, and the homology was 97%-98%. The isolates were highly sensitive to 7 drugs such as ciprofloxacin, ofloxacin, erythromycin, neomycin, amikacin, cefazolin and tetracycline, while were resistant to compound sulfamethoxazole, doxycycline, kanamycin, penicillin, oxacillin, and gentamicin. The results suggested that the yak of the farm had effected Mannheimia haemolytica,and the bacteria had certain drug resistance.