Role of lactoferrin in the treatment of E. coli-induced bovine mastitis

Abstract

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

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

Methods: Eighty lactating cattle and buffaloes, 40 each, aged 4-6 years suffering from BM 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. BM cases were allocated into two groups: group (A) was treated with marbofloxacin combined with LF, 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 LF (2 mg/ml). Group (A) showed significant improvements compared with group (B), with no recurrence rate.

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

Keywords: Bovine mastitis; E. coli; Lactoferrin; Marbofloxacin.

Fig. 1.. Gel electrophoresis and PCR amplification for E. coli. Lane (L): DNA marker; lane (P): positive control; lane (N): negative control, (bp) base pair. (A): 1, 2, 3,4,5,6 lanes are positive for the 16S rRNA gene (253 bp). (B): 1, 2, 3,4,5,6 lanes are positive for the BlaTEM gene (445 bp). (C): 1, 2, 3,4,5,6 lanes are positive for aadB gene (219 bp). (D): 1, 2, 3,4,5,6 lanes are negative for qnrS gene (417bp). (E): 1 and 2 lanes are positive for Sul1 gene (432 bp).