Veterinarska stanica, Vol. 52 No. 2, 2021.
Original scientific paper
https://doi.org/10.46419/vs.52.2.10
Antimicrobial susceptibility of bovine mastitis pathogens from northwestern Croatia in the period 2014 to 2018
Tomislav Sukalić
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Dražen Đuričić
; Mount-trade, Garešnica, Hrvatska
Ivica Pavljak
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Ana Končurat
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Željko Cvetnić
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Jozo Grbavac
; Agronomski i Prehrambeno-biotehnološki fakultet Sveučilišta u Mostaru, Bosna i Hercegovina
Branko Bačanek
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Jadranka Jurmanović
; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Hrvatska
Marko Samardžija
; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska
Abstract
This paper summarises the results of microbiological testing of milk samples from cows suffering from mammary gland inflammation. The examined samples were delivered to the Diagnostic Laboratory of the Križevci Veterinary Institute over a 5-year period, originating from seven counties in northwestern Croatia. Samples were screened by conventional microbiological methods under aerobic conditions. A total of 1264 samples were processed, and a positive result was found in 983 cases (77.76%). In total, 967 strains of bacteria were isolated, while nine samples contained yeast and seven contained algae. Susceptibility to antimicrobial drugs was determined by the disk diffusion method. Among the positive microbiological findings, 14.24% of the isolates belonged to the speciesStaphylococcus aureus (S. aureus), and 60% of these were oxacillin-resistant. S. aureus strains showed the highest susceptibility to AMC (91.4%) and CEQ (90.7%). Coagulase-negative staphylococci (CNS) accounted for 19.23% of positive cases, with the highest sensitivity to CEQ (84.6%). Streptococcus agalactiae was found in 3.36% of positive samples and showed good susceptibility to CPZ and CEQ (87.9%). Other streptococci (according to Lancefield group C, D and others) accounted for 39.47% of positive findings. They showed the highest sensitivity to AMC (95.4%), and CEQ (92.8%). Among the Gram-negative bacteria, Escherichia coli (9.46%) was the most common finding, followed by the genera Pseudomonas, Enterobacter and Klebsiella (3.46%, 2.64% and 0.1%, respectively). Yeasts (Candida spp.) and algae (Prototheca spp.) were isolated in less than 1% of cases. The results show that the percentage of staphylococcal and streptococcal mastitis is similar to previous reports, though an increasing trend in the number of resistant strains of S. aureus was noted. A reliable microbiological finding with an antimicrobial susceptibility test, accompanied with clinical examination is the foundation of mastitis control in our conditions, as different types of microorganisms require different treatment approaches, such as antibiotic selection, vaccination, various drying-off practices, or exclusion of the animal as a last choice.
Keywords
bovine mastitis; pathogens; antimicrobial susceptibility; milk
Hrčak ID:
250312
URI
Publication date:
1.12.2020.
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