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Prototheca spp. i prototekozy u zwierzat

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The aim of the study was to characterise the free coagulase-negative Staphylococcus sp. strains isolated from normal (9.4%) and inflamed quarter milk samples of dairy cows in one herd localised in southern Poland. The isolates were examined phenotypically by cultural features, tube coagulase test, clumping factor (CF), and commercial agglutination test. Total number of 427 strains were cultivated on different media: Congo red agar, DNase medium, mannitol salt agar, and crystal violet agar. About 25% of the strains were examined by the disc diffusion method for their sensitivity to chosen antibiotics. All of the analysed strains showed α, ß, α+ß, or lh type of haemolysis on plate with 5% sheep blood agar, and had positive reaction in CF and agglutination tests, but were negative in tube coagulase test. These strains showed DNase activity and ability to mannitol fermentation; however, none of the strains produced slime. There were variations in growth on crystal violet agar: examined strains belonged to three types of growth (A, E, and C). The strains were highly susceptible in vitro to oxacillin (99.2%), cefoperazone (95.2%), and amoxicillin with clavulanic acid (93.6%), and highly resistant to neomycin (27.2%), tetracycline (21.6%), and streptomycin (20.8%). In conclusion, it can be stated that intramammary infections in cows can be caused by atypical free coagulase-negative strains of Staphylococcus aureus.
The activity of N-acetyl-β-D-glucosaminidase (NA-Gase) was determined in 40 samples of quarter milk from 40 healthy cows, and in 188 samples of secretion from subclinically and clinically inflamed udders, and in 181 sample of raw bulk milk collected from small private farms. The study was performed by ADC apparatuses and diagnostics delivered by ELKABE Ltd. The average activity of NAGase was the following: 125 AFU for health quarters, 220 AFU for the recovered quarters on the 21st day after treatment (s.c.c. 300 000), 260 AFU for the cases of latent udder infections caused by S. aureus or S. agalactiae (s.c.c. below 350 000/ml), 680 AFU for cases of subclinical bacterial or aseptic mastitis (average s.c.c. 3.5 milion/ml), and 1360 AFU for quarters affected with clinical forms of mastitis. The activity of NAGase in raw bulk milk was as follows: 117 AFU for s.c.c. below 200 000/ml, 123 AFU for s.c.c. 201 000-300 000/ml, 139 AFU s.c.c. 301 000-400 000/ml, 143 AFU for s.c.c. 401 000-500 000/ml, and 246 AFU for s.c.c. 0.75-1 mln/ml determined by Fossomatic. It has been noted that the state of healthy of udders and the changes in a quarter milk are determined more precisely by NAGase than by somatic cell count. The „cut off’ indicator and Applied Diagnostics Corporation computer programme are fully appropriate for the estimation of the hygienic acceptability of raw bulk milk.
The aim of the study was to characterize the health status and occurrence of pathological changes in mammary glands as well as to isolate etiological agents of mastitis in different herds. A single clinical examination of the udders of 3673 cows and bacteriological examination of 13,778 aseptically collected quarter milk samples were performed in 32 farms. Clinical forms of mastitis were found in 1.9% to 6.5% of quarters. Subclinical forms of mastitis ranged from 27.7 to 43.4%. Different degrees of damage to the teat end and teat canal were observed in 1.2 to 4.4% of quarters examined. Staphylococcus aureus was isolated from milk in 13.0% of samples, coagulase-negative staphylococci in 18.9%, environmental streptococci in 3.2%, Str. agalactiae in 0.3% and Str. dysgalactiae in 0.5%. In conclusion it can be stated that clinical and subclinical forms of udder inflammations are still a serious problem in some farms in Poland. In bigger farms the most important problem are infections caused by Staphylococcus spp. Environmental streptococci (mostly Str. uberis) and CNS dominate in smaller farms. Interesting is the low percentage of Str.agalactiae regardless of the size of the farm.
The isolates of Staphylococcus aureus strains were examined phenotypically by cultural features, tube coagulase test and clumping factor (CF), and genotypically by conventional PCR. The strains had positive reaction in CF test, but were negative in tube coagulase test. The analysed strains from the same cows in each year expressed also nuc and coa genes. About 25% of the strains were examined by the disc diffusion method for their sensitivity to antibiotics. During three years, the strains were highly susceptible in vitro to amoxicillin with clavulanic acid, oxacillin, bacitracin, and cefoperazone (more than 90%), and highly resistant to tetracycline, neomycin, and streptomycin. Forty randomly chosen strains, and eight strains from the same cows in each year were analy sed for minimal inhibitory concentration of penicillin G using microdilution method. An increasing resistance to the penicillin was noted. Moreover, eight strains, the same in each year, were also examined for ß-lactamase production and methicillin resistance. No ß-lactamase producers and no methicillin resistant strains were found using phenotypic and genotypie methods. In conclusion, it can be stated that antimicrobial susceptibility can change from one year to another.
The aim of the study was to establish the in vitro sensitivity of S. agalactiae (126 strains), S. dysgalactiae (82 strains), S. uberis (419 strains), and Enterococcus sp. (136 strains) isolated from mastitis in cows to 13 antibiotics. Bacteriological examinations of quarter milk samples were conducted with the recommendations of the IDF. Sensitivity to antibiotics was tested by disk diffusion method in Mueller-Hinton agar and performed according to CLSI guidelines. It was found that S. agalactiae strains were the most sensitive to bacitracin (97.6%), cefapirin (96.3%), and amoxicillin (93.7%), and resistant to neomycin (89.7%), tetracycline (49.2%), and cloxacillin (38.9%). S. dysgalactiae showed the highest sensitivity to bacitracin (100%), cefapirin (100%), amoxicillin (97.6%), cephalexin (97.6%), cefoperazone (93.9%), and resistance to neomycin (61.0%) and tetracycline (53.7%). S. uberis strains were mainlv sensitive to cefapirin (98.9%), bacitracin (98.8%), cefquinome (97.6%), amoxicillin (97.4%) and resistant to neomycin (93.3%), tetracycline (35.3%) and lincomycin (22.4%). Enterococcus sp. showed the high sensitivity to amoxicillin (83.8%) and bacitracin (82.4%), and resistance to cloxacillin (76.5%), cephalexin (58.1%), lincomycin (55.9%), neomycin (53.7%), penicillin (48.5%), and tetracycline (36.0%). In conclusion, strains of S. dysgalactiae were more sensitive to tested antibiotics than S. agalactiae, S. uberis, and especially Enterococcus sp. Only 8.8% of S. agalactiae, 4.3% of S. dysgalactiae, 4.3% of S. uberis, and 4.4% of Enterococcus sp. strains were sensitive to all tested antibiotics. The largest diversity in the resistance was found in Enterococcus sp.
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