Pathogenicity of Peptostreptococcus micros morphotypes and Prevotella species in pure and mixed culture

Pathogenicity of Peptostreptococcus micros morphotypes and Prevotella species in pure and mixed culture

van Dalen, P.J.
van Deutekom-Mulder, E.C.
de Graaff, J.
van Steenbergen, T.J.M.
TNO Preventie en Gezondheid

1998

Recently, an atypical rough colony morphotype of Peptostreptococcus micros, a species which is found in ulcerating infections, including periodontitis, was isolated. The virulence of morphotypes alone and in combination with Prevotella intermedia and P. nigrescens was investigated both in vivo and in vitro. All strains tested induced abscesses containing fluid pus in a mouse skin model, and lesions caused by monocultures of the rough morphotype strains of P. micros were statistically significantly larger than those induced by the smooth morphotype strains. Inocula containing both morphotypes produced similar sized abscesses compared to mono-inocula containing the same bacterial load. Both Prevotella species induced small abscesses when inoculated alone, and when Pr. nigrescens was inoculated with one of the other strains, the abscesses were not significantly different from the abscesses induced by the mono-infections of this strain. Synergy, in terms of higher numbers of colony forming units (cfu) in the mixed inocula, was found for all combinations of the rough morphotypes of P. micros and both Prevotella spp. Pus from abscesses caused by combinations of Peptostreptococcus and Prevotella spp. transmitted the infection to other mice, but no abscesses were formed in mice inoculated with pus induced by mono-inocula. These results demonstrated synergic activity between both rough and smooth P. micros strains and oral Prevotella strains. The in-vitro co-culture experiments produced no evidence of growth stimulation. The effect of P. micros strains on the immune system was investigated by testing their ability to initiate luminol-dependent chemiluminescence of polymorphonuclear leucocytes in the presence and absence of human serum. In the latter, the rough morphotype strains initiated higher counts than the smooth morphotype strains. Further work is needed to elucidate the difference in virulence between the smooth and the rough morphotype cells of P. micros and the nature of the interaction with the Prevotella spp.

Health
Abscess
Animals
Bacteroidaceae Infections
Chemiluminescent Measurements
Disease Models, Animal
Gram-Positive Bacterial Infections
Mice
Neutrophils
Peptostreptococcus
Prevotella
Prevotella intermedia
Skin Diseases, Bacterial

http://resolver.tudelft.nl/uuid:8ac4a540-a7d3-44cc-b82a-61c68c8f3b38

234340

0022-2615

Journal of Medical Microbiology, 47 (2), 135-140

article