Some virulence properties and characterization of motile Aeromonas species from milk and white cheese

Yucel N., Erdem B., Kaya D.

INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, cilt.58, sa.2, ss.106-110, 2005 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 58 Konu: 2
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1111/j.1471-0307.2005.00191.x
  • Sayfa Sayıları: ss.106-110


Three hundred and thirty-eight samples of milk and milk products in Ankara were screened for the presence of motile Aeromonas species. The overall frequency of aeromonads in these samples was 27%. As expected, raw milk samples were more contaminated with aeromonads than were other products. Sixty-five (49.2%) of the 132 bulk raw milk samples were contaminated with aeromonads. In 35 of these samples, populations of aeromonads from 1.5 x 10(2) to 3.0 x 10(3) cfu/mL were counted in ampicillin dextrin agar (ADA). Ten (40%) of the 25 raw milk samples sold in the street were contaminated with aeromonads. In eight of these samples, 1.2 x 10(2)-3.0 x 10(3) cfu/mL were counted. Five (16%) of the 31 pasteurized milk and 12 (8%) of the 150 white cheese samples were contaminated with Aeromonas spp., but no countable aeromonads population was noted in ADA. The incidence of A. hydrophila, A. sobria and A. caviae in all samples was found to be 90.2%, 4.3% and 5.4%, respectively. The majority of the strains identified as A. hydrophila and A. sobria were able to produce haemolysin, protease and DNase, while strains identified as A. caviae were only positive for DNase. All isolated Aeromonas species (A. hydrophila, A. sobria and A. caviae) were positive for uptake of Congo red dye. Nevertheless, only strains identified as A. hydrophila and A. sobria showed a high rate of positive results when tested for the production of the Voges-Proskauer reaction and lysine decarboxylase. The results of this work show that motile Aeromonas spp., especially A. hydrophila, are frequently found in these samples. As these products are usually commonly consumed in Ankara, they can pose a risk especially for children, the elderly and immunocompromised individuals.