Çiğ süt ve peynir örneklerinden Staphylococcus aureus ve koagülaz negatif stafilokokların identifikasyonu ve antibiyotik duyarlılığı

AMAÇ: : Bu çalışmada Ankara ilinde çeşitli firma ve mandralardan temin edilen çiğ süt ve peynir örneklerinde koagulaz pozitif stafilokok (KPS), koagulaz negatif stafilokok’ların (KNS) bulunma sıklığı ve bu suş’ların antimikrobiyal dirençliliklerinin belirlenmesi amaçlanmıştır. YÖNTEMLER: Araştırmada incelenen 190 çiğ süt, 90 peynir örneğinden izole edilen KPS ve KNS’ların standart biokimyasal yöntemler kullanılarak cins ve tür düzeyinde identifikasyonları yapılmıştır. İzolatların antimikrobiyal direnç özellikleride disk difüzyon metodu ile değerlendirilmiştir.BULGULAR: İncelenen çiğ süt ve peynir örneklerinden 236’sı koagulaz pozitif stafilokok (KPS), 94’ü koagulaz negatif stafilokok (KNS) olmak üzere toplam 330 stafilokok izolatı elde edilmiştir. Tanımlanması yapılan KPS türleri içinde çiğ süt ve peynir örneklerinde sırasıyla en fazla S. intermedius (%40.0-%44.3) ve S. aureus (%35.0-%20.2); KNS türleri içinde de en fazla S. saprophyticus (%26.4-%43.0) ve S. caseolyticus (%9.2-%14.3) tesbit edilmiştir. Çiğ sütten izole edilen KPS izolatları en fazla ampisiline %62.4 ve penisiline %47.0, KNS izolatlarıda metisiline ve penisiline %39.0 dirençli bulunmuştur. Bununla beraber; peynirden izole edilen KNS izolatları ampisiline %42.8, metisilin, penisilin ve eritromisine de %28.5 dirençli bulunmuştur.SONUÇ: Değerlendirilen gıda örneklerinden izole edilen stafilokok türleri bu gıdaların hazırlanması sırasındaki zayıf sanitasyonun ve çapraz kontaminasyonun göstergesi olabileceği düşünülmektedir. Ayrıca KNS izolatları KPS göre antibiyotiklere daha yüksek oranda dirençli olduğu saptanmıştır.

Identification and antimicrobial susceptibility of Staphylococcus aureus and coagulase negative staphylococci isolated from raw milk and cheese samples

OBJECTIVE: In this study, it was aimed to evaluated raw milk and cheese samples purchased from various markets and dairy production in Ankara, Turkey for the presence koagulase positive staphylococci (CPS) and coagulase negative staphylococci (CNS) and determine of antimicrobial resistance in these strains. METHODS: One hundred ninety raw milk and ninety cheese samples were analyzed for isolation of CPS and CNS by conventional biochemical tests and antimicrobial susceptibilities were studied by disk diffusion method according to the guidelines of Clinical and Laboratory Standards Institute.RESULTS: A total of 330 isolates of staphylococcus spp. consisting of 236 CPS and 94 CNS were isolated from raw milk and cheese samples from different dairy products in Ankara. Isolation and identification of Staphylococci was made using conventional biochemical identification system. Of the CPS species included in this study, the predominant species were S. intermedius (40.0-44.3%) and S.aureus (35.0-20.2%) while; bacteriological cultures of CPS were identified as S. saprophyticus (26.4-43.0%) and S. caseolyticus (9.2-14.3%) in raw milk and cheese samples. The antiobitic susceptibility test results showed that KPS strains isolated from raw milk resistant to ampicillin (62.4 %) and penicillin (47.0%); while CNS strains were resistant to methicillin (39.0%) and penicillin (39.0%). Besides this, CNS strains isolated from cheese samples were resistant to ampicillin (42.8%), methicillin (28.5%) penicillin (28.5%) and erythromycine (28.5%).CONCLUSION: These results suggests the contamination of raw milk and cheese samples by staphylococci spp. indicates poor personel hygiene and cross contamination. In addition, the strains of CNS were much more resistant than CPS to antibiotics.

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