LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (1), 2010 TIMI OARA
ISOLATION AND CHARACTERIZATION OF STAPHYLOCOCCUS XYLOSUS STRAIN FROM SHEEP ABORTION
ANCA SOFIANA SURPAT 1, V. HERMAN 1, CORINA PASCU 1, LUMINIłA COSTINAR 1, SORINA IRIMIE 1, IOANA VĂDUVA 1, B. FAUR 1, MARIA ERBESCU 2
1Faculty of Veterinary Medicine Timisoara, 300645, Calea Aradului No. 119, Timisoara, Romania 2DSVSA Timis E mail: [email protected]
Summary
Staphylococcus xylosus ( S. xylosus ) a commensally skin bacteria was isolated from the liver of one sheep abortion, first on usual media (broth), then by subculturing on blood agar 10%. Identification based on cultural, morphology and biochemistry characters allows framing in the genus and species. In this study, sensitivity of isolated strain was also tested to antibiotics that are used often in medical practice. Keywords: sheep abortion, coagulase negative staphylococci, abortion.
Staphylococcus xylosus is a commensally bacteria commonly found on skin of mammals but also used for its organoleptic properties in manufacturing of fermented meat products (5). It is part of coagulase negative staphylococci, novobiocin resistant, along with S. sciuri , another commensal skin. S. xylosus , is a gram positive coccus, non hemolytic, that forms white colonies on blood agar whose diameter are smaller than 5 mm (2). Because bacteria were quoted by some authors as causative agents of urinary tract infections and endocarditis in humans (3), cows mastitis and sheep dermatitis (1), isolation of S. xylosus presents importance for pathology.
Materials and methods
It was examined a sheep abortion that provided from a flock with no history this season and the abortion wasn’t accompanied by prodromic signs. Following the necropsy examination of abortion, lesions observed were common to several diseases and were represented by oedema of foetus, exsudate inflammation of the subcutaneous connective tissue and serous cavities, hepatic and spleen hyperplasia. For etiological diagnosis was made bacteriological exams using liver abortion. Primary culture was performed on broth and nutrient agar. Culture media were incubated 24 hours at 37°C in aerobic conditions.
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After primary culture, were carried out subculture using agar supplemented with defibrinated blood 10%. Following incubation period, which was 24 hours at 37°C, smears were performed from colonies grown using gram stain. To characterize the biochemical profile of isolated strain was used API Staph kit (bioMerieux, France). The API Staph strip consists of 20 microtubes containing dehydrated substrates. These microtubes were inoculated with bacterial suspension, prepared in API Staph Medium. During incubation, bacterial metabolism produced color changes that were either spontaneous or revealed by the addition of reagent. Antibiogram was carried out by the Kirby Bauer method (disk diffusion), using blood agar 10% and the following discs: novobiocin (10mcg), doxycicline (30 g), penicillin G (10 g), norfloxacyn (30 g), amykacin (30 g), gentamicin (10 g), amoxyclav (30 g ), cephalothin (30 g), neomycin (30 g), fluoron (30 g), erythromycin (15UI). Results reading and interpretation consisted in inhibition zone size induced by antibiotics (4).
Results and discussions
Primary cultures had the following characteristics: uniform, moderate turbidity of broth and no colonies grown on agar. Small white colonies, non hemolytic, S type with irregular edges grows on blood agar 10%. Smears made from these colonies have shown specific morphological characters to staphylococci: gram positive coccus, willing to form piles of cluster. Based on biochemical characters obtained from Api Staph testing and interpreted by ApiWeb software, isolated strain was classified in the species S. xylosus. Table 1 Biochemical behavior of S. xylosus NO . SUBSTRAT RESULTS 1. Blood agar 10% hemolysis Negative 2. Catalase Positive 3. Oxidase Negative 4. Acidification: • D glucose Positive • D fructose Positive • D mannose Positive • D maltose Positive • D lactose Positive • D trehalose Positive • D mannitol Positive • Xylitol Negative • D melibiose Negative • D raffinose Negative • D xylose Positive 116 LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (1), 2010 TIMI OARA
• D saccharose Positive • Methyl α D glucopyranoside Negative • N acetyl glucosamine Positive 5. Reduction: Potassium nitrate Positive 6. Dihydrolase: L arginine Positive 7. Alkaline Phosphatase: β naphthyl phosphatase Positive 8. Acetyl methyl carbinol production: Sodium pyruvate Positive 9. Urease production : Urea Positive
Antibiogram results revealed that isolated strain was resistance to: novobiocin, erythromycin and penicillin, and sensitive to: gentamicin, amoxyclav, cephalothin, neomycin, fluoron, doxycicline, norfloxacyn, amykacin.
Conclusions
From a sheep abortion, it was isolated S. xylosus strain framed in the genus and species based on cultural, morphological and biochemical characters. Isolated strain had the following reaction to antibiotics: • Sensitive to: gentamicin, amoxyclav, cephalothin, neomycin, fluoron, doxycicline, norfloxacyn, amykacin. • Resistance to: novobiocin, erythromycin, penicillin
References
1. Cătană, N., InfecŃii produse de germeni din genul Staphilococcus’’, In: Boli InfecŃioase ale animalelor – bacterioze, eds. Moga, Mânzat, R ., Ed. Brumar, Timisoara, 2001, pp. 325 341. 2. Hans, C., Beck, Anne, M., Hansen, Frants, R., Lauritsen, Metabolite production and kinetics of branched chain aldehyde oxidation in Staphylococcus xylosus, Enzyme and Microbial Technology, 2002, 31, 94 101. 3. Tselenis Kotsowilis, Angelina D., Koliomichalis, Maria P., Papavassiliou, J.T., Acute Pyelonephritis Caused by Staphylococcus xylosus , Journal of Clinical Microbiology, 1982, 16, 3. 593 594. 4. *** BD BBL TM Sensi Disc TM Antimicrobial Susceptibility Test Discs, Becton, Dickinson and Company 5. *** http://www.medscape.com/viewarticle/470277_4, accesat în 26.02.2010
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