Serap SAVAŞAN, Osman KAYA

Sığır mastitislerinde gram-pozitif ve gram-negatif bakterilerin filtrasyon-boyama yöntemi ile çabuk tanısı

Bu çalışmada, filtrasyon-boyama yönteminin klinik ve subklinik mastitisli sütlerde Gram pozitif ve Gram negatif bakteri varlığını belirlemedeki etkinliği incelendi. Filtrasyon tekniğinde, ayıraçla karıştırılan sütler filtrasyon işlemlerinden geçirildikten sonra boyandı ve, sonuçlar değerlendirildi. Yöntemin minimal tanı limitlerini belirlemek için deneysel olarak inokule edilen normal süt örneklerinde, filtrasyon yöntemi ile Gram pozitif bakterilerin 8.96 x $10^5$ 3.80 x $10^6$/ml ve Gram negatif bakterilerin 6.56 x $10^5-8.40 x 10^5$ /ml miktarları saptanabildi, incelenen tüm bakteri türleri, filtrasyon yöntemi ile referens Gram reaksiyonuna uygun sonuçlar verdi ve bakteri inokule edilmeyen kontrol süt örneklerinde filtrasyon ile hatalı pozitif sonuç alınmadı. Yöntemin saha performansını belirlemek için klinik mastitisli 66 ve subklinik mastitisli 52 süt örneği filtrasyon yöntemi ile ve bakteriyolojik olarak incelendi, incelenen klinik mastitis vakalarının %95.5'inde ve subklinik mastitis vakalarının %86.5'inde kültür ile uyumlu sonuçlar alındı. Filtrasyon yöntemindeki hatalı bulgular bakteri varlığının saptanamamasından veya boyanmadan kaynaklandı. Mastitis belirtisi bulunmayan hayvanlara ait 30 süt.örneğinden hatalı sonuç alınmadı. Yöntemin klinik mastitislerdeki sensitivite ve spesifitesi, bakteri varlığını saptama yönünden %96 ve %100, Gram pozitif-negatif ayırma yönünden %98-100; aynı değerler için subklinik mastitislerde sırasıyla %85 ve %100, ve %93-100 olarak bulundu. Sonuçta, kolayca uygulanabilen ve kısa sürede sonuç veren filtrasyon yönteminin, saha koşullarında özellikle klinik mastitislerin etiyolojisi hakkında ön bilgiler verebileceği kanısına varıldı.

Rapid detection of gram-positive and gram-negative bacteria in bovine mastitis

In this study, the ability of a filtration-staining method to detect Gram-positive and -negative bacteria in milk from cows with mastitis was evaluated. The technique consisted of filtration of milk and concentration of bacteria on filter, followed by staining and decoloration of filter. In normal milks inoculated with several bacteria, to determine the minimal detection limits of method, 8.96 x $10^5-3.80 x 10^6$ /ml of Gram-positive and 6.56 x $10^5-8.40 x 10^5$ /ml of Gram-negative bacteria could be detected. Nofalse-positive result was observed in uninoculated control milks. To evaluate the performance of filtration method in mastitic milk, technique was applied to 66 samples from clinical mastitis and 52 samples from subclinical mastitis. Filtration method correctly showed the presence of bacteria in 95.5% ofculture-positive milks with clinical mastitis, corresponding to a 96% sensitivity. Bacteria were correctly detected in 86.5% of milk samples from subclinical mastitis with filtration method, which corresponds to a sensitivity of 85%. The test correctly identified all milk samples without the presence of bacteria both in clinical and subclinical mastitis, corresponding to 100% specificity. Gram-positive and -negative bacteria were correctly identified with a sensitivity of 98 and 100% and specificity of 100 and 98%, in milk samples from clinical mastitis. Sensitivity and specificity for predicting Gram reaction were between 93 and 100 percent in samples from subclinical mastitis. False-staining reactions were observed only in Gram-positive bacteria, including two Streptococcus sp. and one Corynebacterium sp.. It was concluded that filtration method may be used to make a quick decision for gross etiology and treatment of clinical mastitis and with a lesser extent subclinical mastitis, in field conditions.

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