Abstract
Background:
Bovine mastitis is a costly disease in the dairy industry. It is associated with reduced milk production and changes in milk composition and quality. E. coli is the most important pathogen causing bovine mastitis.

Aim:
This study aimed to assess the efficacy of lactoferrin as an enhanced agent when combined with marbofloxacin for the treatment of E. coli bovine mastitis.

Methods:
Eighty lactating cattle and buffaloes, 40 each, aged 4-6 years suffering from bovine mastitis underwent clinical examination. Milk samples were collected for bacteriological examination. The recovered E. coli isolates were subjected to serological, and polymerase chain reaction (PCR) analysis. Bovine mastitis cases were allocated into 2 groups: group (A) was treated with marbofloxacin combined with lactoferrin, and group (B) was treated with marbofloxacin alone.

Results:
Fifty E. coli isolates were recovered. Six serogroup were identified: O55, O103, O26, O11, O44, and O124. All isolates were sensitive to marbofloxacin, while there was resistance to gentamycin and ampicillin (26% each), cefquinome (14%), cefixime (10%), and SuLFamethoxazole and trimethoprim (4%). The molecular identification of E. coli strains revealed that the 16S rRNA gene was present in all identified E. coli strains (100%). All isolates resistant to antibiotics encoded BlaTEM, aadB, and Sul1, whereas the qnrS gene was not detected in any E. coli isolate. The broth dilution method did not detect growth when the marbofloxacin (6 µg/ml) was combined with lactoferrin (2 mg/ml). Group (A) showed significant improvements compared with group (B), with no recurrence rate.

Conclusion:
Lactoferrin can serve as a significant cotreatment agent for treating bovine mastitis. As antibiotic resistance increases, lactoferrin-based drugs could play an important role in providing sustainable, effective alternatives for dairy animals.

Key words: Bovine mastitis, Lactoferrin, E. coli, Marbofloxacin