Streptococcus Morbillorum Research Articles

Oligopeptidase activity of gram-positive anaerobic cocci used for rapid identification.

The amidase and oligopeptidase activities of peptostreptococci, peptococci and anaerobic strains of streptococci were studied. Most of the asaccharolytic species of the Genus Peptostreptococcus, which include Peptostreptococcus micros, Peptostreptococcus magnus, Peptostreptococcus asaccharolyticus, Peptostreptococcus indolicus, and Peptostreptococcus prevotii, had very strong peptidase activities. Peptostreptococcus productus and Peptostreptococcus anaerobius, which are strongly or weakly saccharolytic species, had very weak peptidase activities.Most of the anaerobic strains of streptococci were strongly saccharolytic but their peptidase activities were divided into two groups: a high activity group and a low activity group. The former group includes Streptococcus intermedius, Streptococcus pleomorphus, Streptococcus constellatus, and Streptococcus morbillorum. The latter group includes Streptococcus hansenii and Streptococcus parvulus.Anaerobic cocci were grouped into 7 phenons according to the analysis of their lower fatty acids as metabolic end products, and the indole and nitrate reduction tests. Several amidase and oligopeptidase tests, which are useful for differentiation at the species level in each phenon, were selected to prepare a new scheme for a rapid identification system of anaerobic cocci.

Prevalence of viridans streptococci exhibiting lactose-inhibitable coaggregation with oral actinomycetes.

Fresh oral isolates from human dental plaque were selected on the basis of their spherical morphology. In a double-blind experiment, their species identity and ability to coaggregate with human oral Actinomyces viscosus and Actinomyces naeslundii were determined. Of the 110 isolates characterized, 30 were identified as either Streptococcus mutans, Streptococcus anginosus-constellatus, or Veillonella parvula; none of these coaggregated with the actinomycetes. The remaining 80 isolates were identified as Streptococcus sanguis, Streptococcus mitis, Streptococcus MG-intermedius, or Streptococcus morbillorum. Of these 49 isolates (61%) coaggregated with actinomycetes, and nearly 90% (43 of 49 isolates) exhibited lactose-inhibitable coaggregations. Compared with previously characterized coaggregation properties determined with stock culture strains of streptococci, 82% of the fresh isolates exhibited identical coaggregations. The other 18% made up a new coaggregation group that possessed a related lactose-inhibitable coaggregation pattern. Thus, most fresh isolates that coaggregated exhibited lactose-inhibitable coaggregations with human oral actinomycetes. It is suggested that these coaggregations are mediated by a network of lectin-carbohydrate interactions similar to those already characterized in previous studies with stock cultures of actinomycetes and streptococci.

Microbial surface interactions: Reduction of the haemagglutination activity of the oral bacterium Fusobacterium nucleatum by absorption with Streptococcus and Bacteroides

Oral strains of Fusobacterium nucleatum showed haemagglutination (HA) of sheep red blood cells and attachment of HA-active F. nucleatum fragments to other microorganisms allowed a means of studying microbial surface interactions. HA-active sonicated fragments (SF) prepared from F. nucleatum were mixed with whole cell suspensions of 48 bacterial strains and, after incubation, the whole cells were separated from the non-absorbed fragments by differential centrifugation. Attachment of F. nucleatum fragments to the cells was indicated by a reduction in the HA activity of the SF in the supernatant fluid remaining after absorption with whole cells. HA activity of the microbial cells used for absorption and the detection of F. nucleatum fragments on these cells by an indirect fluorescent antibody technique provided further evidence of attachment. Of the 48 strains tested, 10 absorbed F. nucleatum HA-active fragments. They included Bacteroides gingivalis, Bacteroides fragilis subsp. distasonis, Bacteroides corrodens, Streptococcus morbillorum, Streptococcus sanguis (Blackburn and JC 74) and Streptococcus mutans AHT, BHT, 10449 and 6715. Chelators revealed that F. nucleatum attached to the microorganisms via a Ca 2 +-dependent interaction. Sugar inhibition demonstrated that F. nucleatum attached to the microorganisms via a D-galactose-containing moiety on their surface. A reduction in the absorption of F. nucleatum HA-active fragments by Strep. mutans grown in a higher concentration of sucrose was observed.

Serologic Studies ofStreptococcus intermedius, Streptococcus constellatus,andStreptococcus morbillorumby Crossed Immunoelectrophoresis

A reference antigen-antibody system for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus morbillorum was established with crossed immunoelectrophoresis. A comparison of S. intermedius, S. constellatus, and S. morbillorum with crossed immunoelectrophoresis and crossed immunoelectrophoresis with intermediate gel indicated that S. intermedius and S. constellatus are closely related antigenically with as many as six common cytoplasmic antigens. S. morbillorum was antigenically more distinct; antiserum of one strain of S. morbillorum was monospecific, indicating that specific serogroups of S. morbillorum exist. Crossed immunoelectrophoresis and tandem crossed immunoelectrophoresis revealed that S. intermedius, S. constellatus, and S. morbillorum also share some common antigens with Streptococcus sanguis and Streptococcus mitis, but S. intermedius, S. constellatus, and S. morbillorum are antigenically distinct from Streptococcus mutans and Streptococcus bovis.

Serological reactions of the genus Peptostreptococcus

White male New Zealand rabbits were immunized with soluble antigen preparations (SP) of the following gram-positive anaerobic cocci: Peptostreptococcus anaerobius ATCC 27337 and VPI 5737; P. micros VPI 2618; Streptococcus morbillorum ATCC 27527; P. parvulus VPI 5229; and P. productus ATCC 27340. SP were reacted with homologous and heterologous rabbit antisera in immunodiffusion, immunoelectrophoresis, indirect fluorescent-antibody, and tanned-cell passive hemagglutination tests. Even though each antiserum reacted strongly with its homologous SP, no interspecies reactivity was observed except between P. productus antisera and P. parvulus SP by the passive hemagglutination test. Antisera prepared to both strains of P. anaerobius reacted with the other strain in all serological tests.