LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (1), 2010 TIMIOARA

ISOLATION AND CHARACTERIZATION OF 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 Email: [email protected]

Summary

Staphylococcus xylosus ( S. xylosus ) a commensally skin 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, coagulasenegative 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 coagulasenegative staphylococci, novobiocinresistant, along with S. sciuri , another commensal skin. S. xylosus , is a grampositive , nonhemolytic, 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 KirbyBauer method (diskdiffusion), using blood agar 10% and the following discs: novobiocin (10mcg), doxycicline (30g), G (10g), norfloxacyn (30g), amykacin (30g), gentamicin (10g), amoxyclav (30g ), cephalothin (30g), neomycin (30g), fluoron (30g), 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: • Dglucose Positive • Dfructose Positive • Dmannose Positive • Dmaltose Positive • D Positive • Dtrehalose Positive • Dmannitol Positive • Xylitol Negative • Dmelibiose Negative • D raffinose Negative • Dxylose Positive 116 LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (1), 2010 TIMIOARA

• D saccharose Positive • Methylα Dglucopyranoside Negative • Nacetyl glucosamine Positive 5. Reduction: Potassium nitrate Positive 6. Dihydrolase: Larginine Positive 7. Alkaline Phosphatase: βnaphthyl phosphatase Positive 8. Acetylmethylcarbinol 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. 325341. 2. Hans, C., Beck, Anne, M., Hansen, Frants, R., Lauritsen, Metabolite production and kinetics of branchedchain aldehyde oxidation in Staphylococcus xylosus, Enzyme and Microbial Technology, 2002, 31, 94101. 3. TselenisKotsowilis, Angelina D., Koliomichalis, Maria P., Papavassiliou, J.T., Acute Pyelonephritis Caused by Staphylococcus xylosus , Journal of Clinical Microbiology, 1982, 16, 3. 593594. 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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