Collagen binding by vaginal aggregative lactobacilli

Abstract

Ten autoaggregating vaginal Lactobacillus strains (five of these strains were selected among isolates from sows‘ vaginal swabs and the other five among isolates from cows‘ vaginal swabs) were investigated for their ability to bind type Icollagen (Cn-I). All 10 autoaggregating strains in the range of A_570nm readings 0.118–1.806 bound to immobilised Cn-I (at concentration of 100 μg/ml) in wells of microtitre plates, however, Lactobacillus acidophilus SV31 was much more adherent than the rest of the tested strains. The influence of culture medium on Cn-I binding was confirmed only in 50% of the tested strains when agar-grown cells bound significantly more Cn-I than broth-grown cells. The specificity of the binding was confirmed since the Cn-I binding by lactobacilli was abolished after their preincubation with this protein. The effect of heparan sulphate and hyaluronic acid was tested on 5 vaginal strains displaying the best Cn-I binding in microtitre plates after their cultivationon MRS agar plates. Both selected inhibitors significantly (P < 0.001 or P < 0.01) reduced Cn-I binding by the majority of strains. The presence of the gene coding APF (aggregation-promoting factor) was detected in seven strains (all five sows‘ and two cows‘ Lactobacillus strains) by PCR.