Prevalence of Mastitis Pathogens and Antimicrobial Susceptibility of Isolates From Cattle and Buffaloes in Northwest of Pakistan

Abstract

Mastitis is the most prevalent disease of dairy animals, imparting huge economic losses to the dairy industry. There is always a dire need to monitor the prevalence of mastitis, its bacteriology, and evaluation of antimicrobial susceptibilities for mastitis control and prevention. Therefore, the objectives of this study were to investigate: (i) the prevalence of mastitis in cattle and buffaloes; (ii) identification of bacteria associated with mastitis; (iii) antimicrobial susceptibility of bacterial isolates. Milk samples (n = 1,566) from cattle (n = 1,096) and buffaloes (n = 470) were processed for detection of mastitis using the California mastitis test in the year 2018–19. A total of 633 mastitic milk samples were further processed for bacteriology and antimicrobial susceptibility testing by the disc diffusion method. Overall, the prevalence of clinical and subclinical mastitis was 17 and 57% in both species. Clinical mastitis was higher in cattle (20%) compared to buffaloes (11%), whereas subclinical was higher in buffaloes (66%) than cattle (53%). Besides, month-wise prevalence was higher in hot and humid months in both species. Staphylococci spp. (34%) were the most predominant bacterial isolates from mastitic milk, followed by Escherichia coli (19.4%), Streptococci spp. (9%), and Klebsiella spp. (8%). Most of the bacteria were susceptible to gentamicin (92%) and enrofloxacin (88%), when a panel of 16 different antimicrobials was tested. Nevertheless, most of the isolates were resistant to sulphamethoxazole (99%), lincomycin (98%), oxytetracycline (89%), ampicillin (86%), and doxycycline (85%). This study concludes a high prevalence of mastitis caused by Staphylococcal spp. in cattle and buffaloes belonging to the northwest of Pakistan, and gentamicin and enrofloxacin might be appropriate antimicrobial agents in the treatment of bovine mastitis.

Bacteriology, Antimicrobials Resistance and Susceptibility Profiles of Bacteria from Mastitic Cattle and Buffaloes of Khyber Pakhtunkhwa

“…Thus, CM was highest in cows in comparison to buffaloes however SCM was highest in buffaloes. Mustafa et al (2011) and our recent study (Ali et al, 2021) also reported higher prevalence of CM in cows than in buffaloes. It has been reported that buffaloes are generally more resilient to different diseases such as bovine mastitis due to their strong immune system (Pal and Chakravarty, 2020).…”

“…A total of 541 samples from mastitic animals were further cultured to identify the bacterial pathogens. The identification of bacterial isolates was carried out up to the level of genus as described earlier (Ali et al, 2021). In addition, antimicrobial resistance and susceptibility profiling of the isolated bacteria from mastitic cattle and buffaloes was carried out on Muller-Hinton agar (Oxoid TM , Thermo Scientific Inc. USA).…”

“…The reasons of this variation might be that the prevalence of bacterial pathogens associated with bovine mastitis is varying with topographical conditions and managemental practices. In our most recently published work (Ali et al, 2021), we isolated different bacteria from mastitic cattle and buffaloes, which were highly susceptible to enrofloxacin (86.2%), gentamicin (83.5%), and florfenicol (82.6%). These isolates were resistant to ampicillin (96.5%), sulphamethoxazole (96.4%), streptomycin (95.1%), oxytetracycline (85%), and amoxicillin (78.1%).…”

“…In addition, traumatic and mechanical injuries to the udder are also minor causes of mastitis (Bradley et al, 2002). Approximately 135 different bacterial species have been isolated from mastitic animals; however, about 20 types of bacterial pathogens are reported to be mostly associated with mastitis in dairy cattle (Bradley et al, 2002;Gao et al, 2017;Ali et al, 2021). Amongst the bacterial mastitis causing pathogens, coagulase-positive and -negative staphylococci, streptococci spp.…”

Changes in the lipidome of water buffalo milk during intramammary infection by non-aureus Staphylococci

“…The changes that we identified in the present study on water buffalo are sensibly different from bovine milk, being limited to 72 lipids species that are differentially abundant in the NAS-IMI affected milk. Although water buffaloes are regarded as less subjected to mastitis, this concept is debatable, as mastitis is the most prevalent disease in this species, in both farming conditions where animals are kept in an intensive dairy milk productive system 22 , or where the hygienic environment is suboptimal 51 . Still, at least for what concerns the specific NAS-IMI and the lipidome content, the water buffalo seems much less sensitive to dairy cows, given that our results showed that NAS-IMI induced limited changes in the lipid profile of affected quarter milk.…”