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D L Kasper

Publications and source records attributed to D L Kasper.

At least 163 records · Page 9Linked to original sources
PubMed1981

Antibody to group B Streptococcus type III in human sera measured by a mouse protection test.

Antibody to group B Streptococcus type III (GBS-III) was measured in human plasma and sera by using a test which measures the ability to protect outbred albino mice from an intraperitoneal challenge of GBS-III calculated to be lethal to 90% of the mice (LD90 dose). Of three samples from three different lots of commercial human immune serum globulin, none were protective despite the presence of antibody to the native type III polysaccharide. Nine specimens were tested from recipients of multivalent pneumococcal vaccine, and none were protective. Five specimens were tested from recipients of GBS-III polysaccharide vaccines who had responded with greater than 50 micrograms of specific antibody per ml in the blood. All of these were protective and could be diluted to titers of 1:10 to 1:40. Of two prevaccination sera with low levels of specific antibody, neither was protective. An unexpected finding which may limit the sensitivity of the mouse protection assay was that the human immune serum globulin and human serum with a very low level of antibody appeared to increase the lethality of the GBS-III test strain, resulting in LD50 values reduced to 0.01 of the usual LD50.

Animals↗
PubMed1981

Role of antibody to native type III polysaccharide of group B Streptococcus in infant infection.

The role of maternally acquired antibody to native type III polysaccharide of group B Streptococcus as a determinant of susceptibility for infant systemic infection was investigated. Sera from 111 acutely ill infants with type III group B streptococcal bacteremia and/or meningitis and their mothers, and cord sera from 45 healthy neonates and their mothers who had type III group B streptococcal vaginal colonization at delivery were studied. Sera from each of 111 acutely ill infants contained very low levels of antibody (less than 1.7 microgram/ml, median 0.4 microgram/ml), and a significant correlation with maternal levels was tested for early onset infection (median 0.6 microgram/ml; 4 = .76; P less than .01). Women whose infants remained well had antibody levels greater than 2 microgram/ml in their sera (73%) more often than those whose infants developed symptomatic infection (17%) (P less than .001), and the median level in their sera (12.6 microgram/ml) was considerably higher. Study of sera obtained during convalescence from 86 surviving infants indicated a poor antibody response to infection. In contrast, high levels of antibody were detected in sera from each of five convalescent women with postpartum bacteremia. These data extend earlier observations suggesting the correlation between low levels of type-specific antibody in serum and risk for systemic infection with type III strains of group B streptococci.

Antibodies, Bacterial↗
PubMed1980

Influence of preimmunization antibody levels on the specificity of the immune response to related polysaccharide antigens.

We studied the influence of preimmunization antibody level on the immune response of adults to one of two structurally related yet immunologically distinct type-specific polysaccharides from Type III Group B streptococcus and Type 14 pneumonococcus. Four weeks after immunization with multivalent pneumococcal vaccine, 20 subjects with low levels of antibody to Type III Group B streptococcus antigen had no significant increase in antibody to this antigen (P greater than 0.05), but all volunteers with moderate to high preimmunization antibody levels who were immunized with Pneumovax had significant increases (P less than 0.01). However, the streptococcal antibody response to pneumococcal Type 14 antigen was weaker and briefer than that in 10 adults given Type III Group B streptococcus vaccine(P less than 0.05). Preimmunization antibody levels influenced the immune response to a structurally similar polysaccharide antigen, but specific Type III polysaccharide antigen appeared necessary to induce a primary antibody response in "nonimmune" adults. We conclude that immunization of mothers with pneumococcal vaccine is not likely to prevent neonatal Type III Group B streptococcal infection, despite immunologic similarities between the two organisms.

Adult↗
PubMed1980

The natural history of group B streptococcal colonization in the pregnant woman and her offspring. II. Determination of serum antibody to capsular polysaccharide from type III, group B Streptococcus.

An investigation of the prevalence and persistence of the concentration of antibody to capsular polysaccharide from type III, group B Streptococcus in sera from 93 pregnant women and their newborn infants is reported. In the majority of women, the concentrations of antibody detected in the sera were low (less than 1 microgram/ml). However, sera from women who were colonized with type III strains of group B streptococci contained significantly higher concentrations of antibody than those from noncolonized women (p = 0.027). No appreciable change in antibody concentration was found in sera collected early in gestation when compared to delivery sera. When maternal-cord serum pairs were analyzed, a significant correlation between concentrations of antibody was found, which indicates that this antibody is transplacentally transferred.

Antibodies, Bacterial↗
PubMed1980

The role of specific antibody in alternative complement pathway-mediated opsonophagocytosis of type III, group B Streptococcus.

The native capsular polysaccharide antigen of type III, group B Streptococcus contains a terminal sialic acid residue on each repeating unit that masks all end-group galactopyranose residues and prevents alternative pathway complement activation by adult human sera in the absence of type-specific antibody. The critical role of the sialic acid residues in allowing the organism to evade activating the alternative complement pathway was shown when neuraminidase treatment of the organism converted the bacteria to activators of the alternative pathway as assessed in agammaglobulinemic serum. The requirement for specific antibody in permitting alternative pathway activation by the fully sialated bacteria was shown when sera that contained low levels of specific antibody failed to activate this pathway, and when prior absorption of serum that contained higher type-specific antibody levels with the capsular antigen failed to activate this pathway. The use of C2-deficient sera showed that the calssical pathway was not required for antibody-dependent alternative pathway activation. The use of isotonic, pH 7.5, veronal-NaCl buffer that contained 1% gelatin and that was supplemented to 4 mM Mg++ and 16 mM EGTA and adjusted to pH 7.5 (MgEGTA) ruled out the participation of the C1-bypass pathway. The presence of sialic acid on the bacterial surface is one means of evading an important mechanism of natural immunity, namely activation of complement by the alternative pathway. Only specific antibody, i.e., acquired immunity, can overcome this virulence factor.

Antibodies, Bacterial↗
PubMed1980

Bactericidal antibody and susceptibility to otitis media caused by nontypable strains of Haemophilus influenzae.

We have developed a bactericidal antibody assay to determine the role of circulating antibody to nontypable strains of Haemophilus influenzae in children with otitis media. Antibody infecting strain was present in the acute sera of 2/20 children with otitis media caused by H. influenzae NT; 15/18 of these patients had covalescent specimens with titers greater than or equal to 1:2 (X2 = 13.0, P < 0.001). The acute sera of 95 children with otitis media caused by various organisms were screened for bactericidal activity against a randomly selected H. influenzae NT stain. Antibody was present in 0/28 acute sera of patients whose infection was caused by H. influenzae NT and in 18/67 (26.9% of those whose middleear exudates were sterile or contained other bacterial species (X2 = 9.95, P < 0.01). A bactericidal antibody response generally follows infection of the middlw ear with H. influenzae NT. The absence of antibody to a single strain in the sera of some children appears to be associated with susceptibility to this infection.

Antibodies, Bacterial↗
PubMed1980

Structure and serology of the native polysaccharide antigen of type Ia group B streptococcus.

The native polysaccharide antigen isolated from type Ia group B Streptococcus by using pH-controlled growth conditions and extraction procedures contains D-galactose, D-glucose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in the molar ratio of 2:1:1:1. The structure of the native type Ia antigen has been elucidated; it can be represented by the following repeating unit in which all the side-chain beta-D-galactopyranose units are masked by sialic acid residues: [Formula: see text] Removal of all the sialic acid groups yields the incomplete type Ia polysacharide antigen with exposed terminal beta-D-galactopyranose residues. Antisera to type Ia organisms produced in rabbits according to the Lancefield procedures contain antibodies specific for both the native and incomplete antigens. Although sialic acid is not itself a determinant in the formation of antibodies to the native polysaccharide, it is an essential part of a larger determinant. In order to maintain the high degree of immunologic specificity of the native antigen, this determinant must be at least a trisaccharide unit, because the native polysaccharide as isolated has terminal disaccharide units [alpha-D-NeuAcp-(2-->3)-beta-D-Galp] identical to those found in the human M and N blood group substances and fetuin. Formation of antibodies to the incomplete antigen is due to determinants terminating in beta-D-galactopyranose residues. These determinants are probably generated by the removal of the masking sialic acid residues from the cell-associated native polysaccharide by degradative processes that occur in organisms grown without pH control.

Antigens, Bacterial↗
PubMed1980

Legionella pneumophila: growth inhibition by human pharyngeal flora.

Several bacterial isolated from human pharyngeal cultures specifically inhibited the growth of Legionella pneumophila. The inhibitory substance from two strains (Streptococcus species 1-3 and Staphylococcus saprophyticus KC) was isolated from a broth supernatant. The inhibitor was active against all strains of L. pneumophilia tested, including five strains of L. pneumophila serogroup 1 and one strain each of serogroups 2, 3, and 4. The substance did not inhibit growth of 18 fresh clinical and laboratory pathogens (12 general). The substance was dialyzable, was resistant to head and proteolysis, and did not precipitate with ammonium sulfate. Nicotinamide adenine dinucleotide, produced by several upper respiratory tract organisms, did not inhibit L. pneumophila, and L. pneumophila could not be isolated when Streptococcus species 1-3, S. saprophyticus KC, and L. pneumophila were cocultivated. These properties may in part explain the difficulty of isolation and may aid in the identification of L. pneumophila.

Culture Media↗
PubMed1980

Variations of Bacteroides fragilis with in vitro passage: presence of an outer membrane-associated glycan and loss of capsular antigen.

The amount of capsular antigen produced by Bacteroides fragilis appears to decrease significantly with in vitro passage on blood agar plates of strain 23745. This decrease in the quantity of isolable capsule is associated with the emergence of a small transparent colony type variant. The small colony type strain also has a glycogenlike material associated with its outer membrane. This glycogen is found intracellularly but is not associated with the outer membrane on the mucoid colony variant that predominates after passage in animals--the large colony type. No concomitant alteration in outer membrane proteins or lipopolysaccharides is associated with this colonial transformation. Electron micrographs, with either ruthenium red staining or indirect ferritin antibody staining of the capsular antigen, confirm the relative loss of capsule with in vitro passage. Thus, care must be taken during in vitro studies of the antigenic structure of B. fragilis to define the degree of passage of the strain.

Animals↗
PubMed1980

Serum antibody response to Bacteroides fragilis in women with abscesses following hysterectomy.

To determine the role of Bacteroides fragilis in the development of infectious complications following hysterectomy, serum antibody to the capsular polysaccharide was measured with a radioactive antigen-binding assay in 53 women before and several days after surgery. Patients with postoperative abscess formation had a significantly greater mean increase in antibody concentration (4.91 micrograms/ml) than those without complications (0.62 micrograms/ml), those with wound infection (1.90 micrograms/ml), those with pelvic cellulitis (0.63 micrograms/ml), and those with febrile morbidity (0.95 micrograms/ml). There were no significant differences among the latter 4 groups. The authors conclude that B fragilis may play an important role in abscess formation following hysterectomy, but is infrequently involved in other infectious complications of this procedure.

Abscess↗
PubMed1979

Rapid diagnosis of Bacteroides infections by indirect immunofluorescence assay of clinical specimens.

43 specimens from a variety of sites were directly examined by indirect immunofluorescence assay (I.F.A.) with specific antisera against the capsular polysaccharide of Bacteroides fragilis and pooled antisera against a number of serotypes of Bacteroides sp. (all of the former B. fragilis subspecies). The findings were compared with those of routine anaerobic bacteriology and gas liquid chromatography for short chain fatty acids. Examination by I.F.A. was a sensitive (100%) and specific (90.3%) means of identifying B. fragilis. Use of the pooled serum was sensitive (100%) but less specific (64.3%) than the capsular antiserum (90.3%) although it had the advantage of detecting Bacteroides species other than B. fragilis. The capsular serum I.F.A. gave 9.7% false positives and no false negatives. The predictive value of a positive identification of B. fragilis in a clinical specimen using this anticapsular serum I.F.A. test was 80%; with the pooled Bacteroides group-serum it was 60%. The predictive value of a negative test was 100% for both sera, indicating that a negative I.F.A. test is a reliable index of the absence of Bacteroides from the culture I.F.A. of clinical material provides a rapid (less than 2 h) specific and sensitive means for the diagnosis of B. fragilis infections and would be of use in a clinical laboratory.

Abdomen↗
PubMed1979

Immunodeterminant specificity of human immunity to type III group B streptococcus.

The type III polysaccharides of group B Streptococcus in its native state chemically consists of glucose, galactose, glucosamine, and sialic acid. The core of this polysaccharide lacks sialic acid and precipitates with type III antiserum to give a partial identity with the precipitate between the native antigen and this serum. The core determinant is immunochemically similar to the capsular polysaccharide of type XIV Streptococcus pneumoniae, while the native type III group B streptococcal polysaccharide does not cross-react with type XIV pneumococcal antiserum. In human sera, it is antibody directed to the native antigen which correlates very highly with opsonic immunity (r = 0.94) while a poorer correlation exists between antibody to the core antigen and opsonins (r = 0.51 P less than 0.001). In natural infections, as association exists between low levels of maternal antibody to the native antigen and risk of disease in the infant. This association is not true for antibody to the core structure, where both infected infants and their mothers have much higher levels of antibody to the core than the native antigens. Infected infants are also more likely to respond to infection by developing antibody to the native antigen. Immunization of 12 adults with multivalent pneumococcal polysaccharide induced significantly better antibody response to the core antigen than to the native, and this vaccine induced opsonic activity in only one recipient. Immunization of adults with type III group B streptococcal antigens induced antibody to the native determinant which correlated with opsonic activity. Therefore, it would appear that native group B streptococcal polysaccharides will provide the best candidate antigens for immunization.

Antibodies, Bacterial↗
PubMed1979

Group B streptococcal colonization and antibody status in lower socioeconomic parturient women.

This investigation was undertaken to determine the prevalence of group B streptococcal vaginal and throat colonization among lower socioeconomic pregnant women and the antibody concentration to the capsular polysaccharide antigen of type III group B streptococcus in their sera. Group B streptococci were recovered from 28.6 per cent of the 112 women studied; vaginal colonization was detected in 23.4 per cent, throat colonization in 4.7 per cent, and colonization at both sites in 0.9 per cent of the patients, respectively. Among these isolates of group B streptococci, serotypes III (39.5 per cent) and II (30.3 per cent) predominated. No differences were found between colonized and noncolonized women with respect to age, race, marital status, or parity. The majority of all women studied had low concentration of antibody in serum (less than 1.0 microgram per milliliter). However, women with isolation of type III group B streptococci from cultures at the time sera were collected had significantly higher concentrations than did women without group B streptococci from cultures at the time sera were collected had significantly higher concentrations than did women without group B streptococcal colonization.

Adolescent↗
PubMed1979

Rapid diagnosis of type III group B streptococcal meningitis by latex particle agglutination.

A latex particle agglutination assay was developed to detect type III group B streptococcal antigen in cerebrospinal fluid. Agglutination was observed in each of 12 initial and 54% of 26 subsequent CSF specimens obtained a mean of 53 hours after the institution of antimicrobial therapy. Latex agglutination was more sensitive than countercurrent immunoelectrophoresis for the detection of type III group B streptococcal antigen in CSF from neonates and young infants with meningitis.

Antigens, Bacterial↗
PubMed1979

Electron microscopic definition of surface antigens of group B Streptococcus.

Strains representing each of the five serologically distinct types of group B Streptococcus and variant strain 090R, which is devoid of type-specific polysaccharide, were studied by electron microscopy after incubation with various ferritin-conjugated antibodies. Ferritin-conjugated types Ia, II and III antibodies localized on homologous cells in a pattern that defines the capsular location of the type Ia, II, and III polysaccharide antigen. Type Ib and Ic cells have surface antigens to which ferritin-labeled antibodies to both capsular polysaccharide and a common surface protein attach.

Animals↗