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Biomedical subjects

L W Wannamaker

Publications and source records attributed to L W Wannamaker.

At least 73 records · Page 4Linked to original sources
PubMed1975

Newly recognized distinctive M protein associated with certain M type 1 group A streptococci.

Immunological and epidemiological characteristics of M1T1 and M1T8 (T8, 25, Imp.19) group A streptococci isolated in Egypt have been described. Both strains possess a common M1 antigen. The M1T8 strains possess a second antigen which has the immunological and biological characteristics of M protein. The M1T1 strains do not possess this second M antigen. Absorbed rabbit antisera which are specific for this second antigen do not react with extracts of any of the known M protein serotypes. This second antigen is therefore a newly recognized M protein. The M1T1 and M1T8 strains had mutually exclusive geographical and temporal distributions. This finding may have been a consequence of the immunity which occurred after the initial occurrence of the M1T8 strain.

Absorption↗
PubMed1975

Dynamics of the immune response in rabbits immunized with spreptococcal extracellular antigens: comparison of the Streptozyme agglutination test with three specific neutralization tests.

The dynamics of the immune response to streptococcal extracellular antigens as measured by the streptozyme agglutination test have been defined in experimental animals andcompared with the dynamics of the immune response as determined by three established neutralization tests for streptococcal antibodies (ASO, anti-DNase B,and anti-NADase). In rabbits immunized with streptococcal extracellular Streptozyme-measured antibodies rose more quickly and peaked earlier than did antibodies to streptolysin O, streptococcal DNase-B, and streptococcal NADase. Additional studiesrevealed that the early peak was primarily due to 2-mercaptoethanol-sensitive (19S) antibody and that the later rise in Streptozyme-measured antibodies was due to 2-mercaptoethanol-resistant (7S) antibody. Preliminary observations using sucrose gradient ultracentrifugation tended to confirm this interpretation. These data provide a possible explanation for the early detection of a streptococcal antibody response by the Streptozyme test which has also been described in humans. The data suggest a theoretical advantage for the Streptozyme agglutination test in patients with streptococcal infections and their sequealae. However, the complexity of the Streptozyme reagent suggests that more extensive studies are needed to assure the consistent reproductivity of results with different lots of the test reagent.

Agglutination Tests↗
PubMed1975

Streptococcal infections--updated.

Streptococci are amont the most common bacterial pathogens physicians encounter in practice. Infections with streptococci continue to occur with significant frequency despite the general sensitivity of these organisms to a variety of widely used antibiotics. In newborn infants and other special patient groups, streptococci may produce fulminant and fatal sepsis (Table 1). In normal children and adults, infections usually are short term and often mild or unrecognized but with the possibility of resulting, unpredictably, in nonsuppurative complications some weeks or months later. Although scarlet fever has become an unusual and clinically attenuated disease, its rashless analog, streptococcal pharyngitis, presents thorny problems in the differential diagnosis of symptomatic patients and in the detection of subclinical infections. Erysipelas now is a rare disease, but recent studies have confirmed that streptococci often are the primary etiologic agent in impetigo, another type of skin infection--with peculiar bacteriologic and epidemiologic features. Infections with group D streptococci have always been a special case because of their frequent resistance to penicillin, and group B streptococci (also somewhat resistant) present special problems in the perinatal period. Streptococci may appear in unexpected places or guises (see Table 1). Thus, the modern physician has little reason to relax in his vigilance for and knowledge of streptococcal infections.

Acute Disease↗
PubMed1974

Comparison of the antibody response to streptococcal cellular and extracellular antigens in acute pharyngitis.

The antibody response to the group A carbohydrate moiety of the streptococcal cell wall is of special interest because of its postulated role in the pathogenesis of rheumatic valvulitis. The immune response to this somatic antigen was measured in 159 children with culture-proved group A streptococcal pharyngitis and was compared with that to two extracellular antigens of the Group A streptococcus: streptolysin O and streptococcal DNase B. The data suggest that the maximum anti-A-carbohydrate rise occurs soon after the onset of streptococcal pharyngitis in a fashion similar to the response to some streptococcal extracellular antigens. However, the anti-A-carbohydrate antibody response appeared to be a less sensitive indicator of streptococcal upper respiratory tract infection.

Adolescent↗
PubMed1974

Simplified extraction procedure for serological grouping of beta-hemolytic streptococci.

An adaptation of the nitrous acid extraction of streptococci proved to be a reliable and practical method for the preparation of extracts for routine serological group identification. The extracts of all groups tested gave strong capillary precipitin reactions as well as reactions of double diffusion in gel. For routine grouping, extracts were prepared from the first one-half-plate subculture of the initial throat culture. The technique is simple and reliable, and it requires a minimum of technical skill, reagents, and equipment. Its use would facilitate epidemiological surveillance of group A streptococci and rapid diagnosis of streptococcal infections at a low cost.

Antigens, Bacterial↗
PubMed1974

CAMP factor of group B streptococci: production, assay, and neutralization by sera from immunized rabbits and experimentally infected cows.

Quantitative assay methods for CAMP factor activity of group B streptococci and for neutralization of this activity by animal sera are described. The course of the CAMP reaction is influenced by preincubation of red cells with staphylococcal beta-hemolysin and the rate of the reaction by the concentration of CAMP factor. The production of CAMP factor is enhanced by substitution of maltose for glucose in culture broth. Rising inhibitory titers to CAMP activity in sera of rabbits injected with sterile culture supernates of group B streptococci suggest that CAMP factor is an antigen in the rabbit. Cows with experimentally induced group B streptococcal mastitis also demonstrated significant rises in neutralizing titers for CAMP activity.

Animals↗
PubMed1973

Group A streptococcal bacteriocin. Production, purification, and mode of action.

A bacteriocin, streptocin A, was isolated from the supernatant fluid of tryptic soy broth cultures of Group A streptococcus strain FF-22. Evidence was obtained which supports the view that the failure to recover active streptocin A after growth of the producer strain in certain fluid media is due to the inactivation of the bacteriocin by concomitantly synthesized streptococcal proteinase. The bacteriocin was purified 139-fold and the active product appeared to be of uniform size, having a molecular weight of approximately 8,000. Streptocin A was bactericidal, but not lytic, for a susceptible Group A streptococcus and the lethal effect was markedly temperature dependent. The bacteriocin inhibited the synthesis of DNA, RNA, and protein, and also prevented the uptake and incorporation of glucose by the sensitive cells. Degradation of RNA occurred, but appeared to be less than that produced by a staphylococcal bacteriocin. This effect may be due to differences in the killing potency of the two bacteriocins in preparations having similar inhibitory activity when measured by lawn culture assays.

Alanine↗
PubMed1973

Intergroup phage reactions and transduction between group C and group A streptococci.

In a study of intergroup reactions, four virulent Group A streptococcal phages were found to form plaques in high titer on lawns prepared from a number of Group C streptococcal strains. Whether the phages were propagated on the homologous (Group A) strain or a heterologous (Group C) strain did not appear to influence consistently the plaque-forming efficiency on lawns prepared from a homologous (Group A) or a heterologous (Group C) strain or to alter significantly the percent of Group C strains which showed plaque formation. Considerable variability was found in the ability of temperate phages to lyse strains of a heterologous group. A single Group C indicator strain was lysed by a high percentage of freshly induced temperate Group A phages. A single temperate Group C phage lysed a significant proportion of Group A strains when freshly induced or when propagated on a Group A strain. Intragroup transduction of streptomycin resistance was demonstrated between Group C strains. Intergroup transduction of streptomycin resistance and also bacitracin resistance was achieved between Group C and Group A streptococci. These observations provide evidence that Group A streptococci can serve as recipients in intergroup transmission of genetic information. Ultraviolet irradiation of the transducing lysate and lowering the propagation temperature of the transducing lysate increased the frequency of transduction in both the intragroup and intergroup transduction systems.

Bacitracin↗
PubMed1973

Localization and characterization of the hippuricase activity of group B streptococci.

Studies are presented on the isolation, localization, and characterization of hippuricase activity of group B streptococci. Washed, intact cells, live or heat killed at 56 C, exhibited hydrolysis of hippuric acid, but cell-free filtrates of the organism did not. Excellent hippuricase activity was recoverable from supernatant fluids of mechanically disrupted cells, and evidence suggests that it exists largely intracellularly. Characteristics of the hippuricase preparation are consistent with the view that the biologically active principle is an enzyme. A quantitative microtiter technique has been developed which is useful in titrating enzymatic activity and antibody neutralization. Sera from rabbits immunized with filtered preparations neutralized hippuricase activity.

Amidohydrolases↗
PubMed1973

Kinetic studies on the interaction of bacteriophage type 71 staphylococcal bacteriocin with susceptible bacteria.

Kinetic studies on the interaction of the bacteriocin produced by phage type 71 Staphylococcus aureus with susceptible bacterial cells were undertaken. Survivors among susceptible bacteria to which the bacteriocin has been added can be rescued after trypsin treatment. The bacteriocin adsorbs very rapidly to susceptible streptococcal cells at a time when killing of the cells is only minimal. Heat-killed or mechanically disrupted cells are also effective in adsorbing the bacteriocin. Adsorption is comparable at 37 C and 25 C, but is less pronounced at 4 C. Elution of adsorbed bacteriocin could not be achieved by heating, by varying pH, or by using different concentrations of sodium chloride solutions. Surface M protein of streptococcal cells plays no role in the adsorptive process. Adsorption is specific in that only susceptible bacteria, but not resistant ones, are capable of adsorbing the bacteriocin.

Adsorption↗