Deepak KUMAR, Anita TEWARİ, Rashmi SİNGH, Suresh Prasad SİNGH

Comparison of a new chromogenic medium with standard media for isolation and identification of Bacillus cereus

Amaç: Bu çalışmanın amacı yeni bir kromojenik besi yeri olan ve izolasyon, identifikasyon ve bakteri sayımı için önerilen HiCrome Bacillus cereus agar (HIMEDIA®)'ın standart selektif besi yerleri (PEMBA ve MYP) ile karşılaştırılmasıdır. Gereç ve Yöntem: Etten izole edilen ve PZR ile doğrulanan 29 B. cereus izolatı 3 çeşit besi yerinin test edilmesinde kullanıldı. Bu çalışmada kullanılan tüm izolatlar araştırmada önceden tiplendirildi. Bulgular: Tipik koloniye sahip izolat oranlarına bakıldığında, MYP'de 29 koloninin 27'sinin, HiCrome BCA ve PEMBA'da ise 25'şer adet koloninin olduğu belirlendi. Her 3 çeşit besi yerinde de zayıf reaksiyon görülmekle birlikte bu üremeler PEMBA, MYP ve HiCromeBCA'da sırası ile 4, 2 ve 4 izolat idi. Zayıf reaksiyon veren koloni sayısı MYP'e nispeten PEMBA ve HiCromeBCA'da daha fazla sayıda idi. Öneri: Bu çalışma ile MYP besi yerinin B. cereus'un izolasyon ve identifikasyonu için PEMBA ve HiCromeBCA'ya göre daha iyi olduğunu gösterildi. B. cereus'un teşhisinde kullanılan kromojenik besi yeri, konvansiyonel besi yerine göre iyi bir seçenek olarak görünmemektedir. Ancak bakteri sayımının yapılmasında, standart besi yerine göre daha üstün olduğu belirlenmiştir.

Bacillus cereus'un izolasyon ve identifikasyonunda standart besi yerleri ile yeni kromojenik besi yerinin karşılaştırılması

Aim: The aim of this study was to compare a new chromogenic plating media HiCrome Bacillus cereus agar (HIMEDIA®) against two standard selective plating media (PEMBA and MYP), recommended for isolation, identification and enumeration of Bacillus cereus. Material and Method: Twenty nine B. cereus PCR confirmed isolates of meat origin were used for evaluation of the three media. All the isolates used in this study were already characterized during research work. Results: The proportion of isolates with typical colonies was highest in MYP with 27 colonies out of 29, while HiCrome BCA and PEMBA both showed only 25 typical colonies. Isolates with weak reaction were found on all three plating media but the weak reactions were shown by 4, 2 and 4 isolates on PEMBA, MYP and HiCrome BCA, respectively, thus they were more for PEMBA and HiCrome BCA as compared to MYP media. Conclusions: Our survey showed that the MYP media was better than PEMBA and HiCrome Bacillus cereus agar for isolation and identification of B. cereus. Chromogenic media did not represent a very good alternative to the conventional standard media for diagnostic of B. cereus but it was found superior than standard plating media for enumeration of the bacteria.

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