COMPARISON OF BACTERIAL PATHOGENS ASSOCIATED WITH DIFFERENT TYPES OF BOVINE MASTITIS AND THEIR ANTIBIOTIC RESISTANCE STATUS IN BANGLADESH

Abstract

Background: Mastitis is one of the most prevalent complex diseases of mammals with high economic impact in dairy industry worldwide. Most of the published inland reports on bovine mastitis are mainly based on sub-clinical mastitis and some extent to clinical types. Objectives: The main objectives of this study are (a) to compare the bacterial pathogens associated with sub-clinical, clinical and chronic mastitis, and (b) to detect the antibiotic sensitivity and resistance status of the isolated bacteria from different types of mastitis. Materials and Methods: A total of 539 quarter milk samples, collected from lactating cows of Rajshahi and Mymensingh districts were subjected to standard bacterial culture and biochemical tests during the period of 2010-2011. Antibiogram test was done on bacteria isolated from sub-clinical (n = 444), acute (n = 35) and chronic (n = 60) mastitis cases include Staphylococcus spp., Streptococcus spp., Bacillus spp. and E. coli in 78.54%, 80% and 71.67% milk samples as a single and 21.46%, 20% and 28.33% as mixed infection, respectively. Results: The Staphylococcus spp. was recorded as major pathogen for all the sub-clinical (42.15%), acute (45.71%) and chronic (41.67%) mastitis cases. The right hind quarters were found significantly (p < 0.05) more affected with sub-clinical, acute and chronic types of mastitis than other three quarters in cows. The highest sensitivity (up to 100%) was recorded with gentamicin, ciprofloxacin, oxytetracycline and enrofloxacin against all the tested four organisms isolated from sub-clinical, clinical and chronic mastitis cases. Antibiotic resistance was highly prevalent, especially streptomycin (70-100%), amoxicillin (30-100%) and ampicillin (0-100%) against the four isolated bacteria of three different types of mastitis. Conclusions: It may be concluded that there is a need to establish a nationwide plan for monitoring the resistance of antibiotics and ensure the cautious use of antibiotics in the veterinary medical practices. Keywords: Bovine mastitis, Clinical mastitis, Subclinical mastitis, Chronic mastitis, Mastitic bacterial pathogens and Antibiogram