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E C Gotschlich

Publications and source records attributed to E C Gotschlich.

At least 109 records · Page 6Linked to original sources
PubMed1976

Strain-specific variation in the protein and lipopolysaccharide composition of the group B meningococcal outer membrane.

Variation in the protein and lipopolysaccharide composition of the meningococcal outer membrane may be due to either serotype differences or to changes in cultural conditions. There are 12 antigenically distinct serotypes of group B meningococci, and these are associated with distinct major outer membrane protein patterns on sodium dodecyl sulfate-polyacrylamide gels. In most strains the predominant outer membrane protein carries the serotype-specific determinant. Certain strains, when grown under similar conditions in different media showed an altered membrane composition. The type 2 strain, M986, grown in modified Frantz medium-A, had a reduced amount of the major 41,000-dalton protein while a 28,000-dalton protein predominated. The altered protein composition may be related to changes in cell metabolism as reflected by the pH of the medium after growth. Growth of the organism in Frantz medium-B caused a negligible drop in pH and the 41,000-dalton protein remained predominant. There was also variation associated with changes in the growth rate. Increasing the aeration caused a concomitant increase in growth rate and cell yield. We observed two quantitative changes in outer membrane proteins in four of seven strains examined: (i) where only a single major protein changed (three strains), and (ii) where an increase in one protein component was associated with a decrease in another protein (one strain). When the strains were grown in tryptic soy broth (Difco Laboratories, Detroit, Mich.) with either high or low aeration, the total protein in the outer membrane remained constant. In contrast, with high aeration there was a significant increase in lipopolysaccharide. These studies suggest that the cell surface proteins may be altered by the organism to meet a variety of environmental conditions.

Air↗
PubMed1975

Clinical evaluation of group A and group C meningococcal polysaccharide vaccines in infants.

Group A and group C meningoccal polysaccharide vaccines were evaluated in infants. No significant local or systemic reactions were observed with 908 doses of vaccine given to 396 infants between 3 and 12 mo of age. The antibody response varied with the age of the infant, vaccine dose, molecular weight of vaccine, prior immunization with vaccine, and prior exposure to naturally occurring cross-reactive antigens. Only 7% of 3-mo-old infants had detectable antibody responses to primary immunization with 5-200 mug of A vaccine, presumably because of suppressive effects of high concentrations of maternal anti-A. More than 90% of 7- and 12-mo-old infants responded to A vaccine, achieving geometric mean anti-A concentrations of 0.38 and 0.98 mug/ml, respectively. The dose-response curve was flat between 10 and 200 mug of A vaccine. Geometric mean anti-A concentrations of 2.51 and 4.00 mug/ml were induced in 7- and 12-mo-old infants by booster injections of A vaccine. Approximately 90% of 3-mo-old infants had detectable antibody responses to primary immunization with C vaccine. The 100-mug dose appeared to be optimal, resulting in geometric mean anti-C concentrations of 0.49, 1.55, and 2.64 mug/ml in 3-, 7-, and 12-mo-old infants, respectively. Significant booster responses were not observed with C vaccine. Indeed, except for the 10-mug dose, booster injections of C vaccine in 7- and 12-mo-old infants resulted in lower anti-C concentrations than did primary immunizations.

Age Factors↗
PubMed1974

An outer membrane protein of Neisseria meningitidis group B responsible for serotype specificity.

Meningococcal groups B and C have been subdivided into a series of serotypes based upon the antigenic specificity of protein serotype antigens (STA). The purpose of these studies was to obtain the STA by gentle methods and determine its anatomic location in the meningococcal cell. The STA was extracted from group B meningococcal strains by either 0.2 M LiCl or 0.2 M CaCl(2) and isolated from the extracts by gel filtration on Sepharose 6B or by pelleting the STA by centrifugation at 100,000 g. The isolated STA was a lipoprotein-lipopolysaccharide complex with a mol wt of approximately 4 x 10(6) daltons. Antisera prepared against the type 2 STA were bactericidal only for homologous serotype strains. The STA proved to be a constituent of the outer membrane of the cell envelope. This was shown by SDS-polyacrylamide gel electrophoresis (PAGE) of the isolated outer membrane and of the purified STA. The type 2 STA complex contains three principal proteins, one of which is predominant with a mol wt of 41,000 daltons. The type 2 STA was dissociated by Triton X-100 and separated by sucrose gradient isodensity centrifugation into two peaks. The denser peak (rho = 1.26 g/cm(3)) contained the majority of the 41,000 dalton major outer membrane protein as shown by SDS-PAGE. This peak also contained the type 2 antigenic determinant. Thus the major outer membrane protein, extracted as part of a lipoprotein-lipopolysaccharide complex, contains the type 2 STA determinant.

Antigens, Bacterial↗
PubMed1974

Gonococcal disease.

Explore the source record for details and available documents.

Antibodies, Bacterial↗
PubMed1974

Inhibition of bacterial growth by beta-chloro-D-alanine.

The D- and L-isomers of beta-chloroalanine inhibit the growth of Diplococcus pneumoniae, Streptococcus pyogenes, Bacillus subtilis, and Escherichia coli. With pneumococcus the inhibition by beta-chloro-D-alanine is completely prevented by either D-alanine or D-alanyl-D-alanine, while L-alanine is not effective in preventing the inhibition. The inhibition of growth by beta-chloro-L-alanine is not affected by D-alanine and is only partially prevented by high concentrations of L-alanine. The intracellular free alanine in untreated E. coli and B. subtilis is about 95% in the D-configuration while the free intracellular alanine in both organisms after treatment with beta-chloro-D-alanine is predominantly the L-isomer. These results suggested that the beta-chloroamino acid inactivates alanine racemase (EC 5.1.1.1). Indeed, when extracts of E. coli or B. subtilis were treated with beta-chloro-D-alanine, the activities of alanine racemase and of D-glutamate-D-alanine transaminase were found to be 90-95% inhibited. Studies with mice have shown that beta-chloro-D-alanine is an effective antibacterial agent in vivo againt D. pneumoniae, S. pyogenes, and E. coli.

Alanine↗
PubMed1974

Isolation and characterization of the outer membrane of Neisseria gonorrhoeae.

The cell envelope of Neisseria gonorrhoeae strain 2686, colonial type 4, was isolated from spheroplasts formed by the action of ethylenediaminetetraacetic acid and lysozyme. Isopycnic centrifugation of osmotically ruptured spheroplasts resolved the cell envelope into two main membrane fractions. Chemical and enzymatic analyses were used to characterize these isolated membranes. Succinic dehydrogenase, reduced nicotinamide adenine dinucleotide oxidase, and d-lactate dehydrogenase were localized in the membrane fraction of buoyant density, rho degrees = 1.141 g/cm(3). Lipopolysaccharide and over half of the cell envelope protein were associated with the membrane that banded in sucrose at rho degrees = 1.219 g/cm(3). These fractions were consequently designated cytoplasmic and outer or L-membrane, respectively. Sodium dodecyl sulfate-polyacrylamide electrophoresis of isolated membranes demonstrated the relative simplicity of the protein spectrum of the outer membrane. The majority of the protein in this membrane could be accounted for by proteins of molecular weights 34,500, 22,000, and 11,500. The protein of molecular weight 34,500 accounted for 66% of the total protein of the L-membrane. Isoelectric precipitation at pH 4.6 with 10% acetic acid selectively removed this protein from a 150 mM NaCl in 10 mM tris(hydroxymethyl)aminomethane-hydrochloride, pH 7.4, extract of purified outer membrane. At pH 4.0, the other proteins of the L-membrane were precipitated. It was concluded that the membrane components of the cell envelope of N. gonorrhoeae were similar to those of other gram-negative bacteria. The cell envelope fractions described here, in particular the outer membrane, are sufficiently well defined to provide a valuable tool for future biochemical and immunological studies on N. gonorrhoeae.

Bacterial Proteins↗
PubMed1973

Electron microscopic studies on streptococci. II. Group A carbohydrate.

The location of Group A carbohydrate in the streptococcal cell wall has been studied by several ultrastructural techniques. The findings, based largely on use of ferritin- and horseradish peroxidase-conjugated antibodies, are interpreted as demonstrating a discrete laminar distribution of the group-specific polysaccharide. This carbohydrate layer is located on the outermost surface of the cell wall in organisms lacking protein cell wall antigens.

Animals↗
PubMed1973

Studies on gonococcus infection. 3. Correlation of gonococcal colony morphology with infectivity for the chick embryo.

Comparable numbers of types 1, 2, 3, and 4 gonococci were placed on the intact chorioallantoic membrane of 236, 10-day old chick embryos. Types 1 and 2 organisms produced infection and could be cultured from chorioallantoic fluid 2 days later significantly more often (69%) than types 3 and 4 organisms (12%, P < 0.001). This confirms in an animal model the same correlation between colony types and infectivity observed in human volunteers and suggests that types 1 and 2 gonococci possess a fundamental virulence characteristic which is absent from types 3 and 4 organisms. Gonococcal infection of the chick embryo chorioallantoic cavity remains a useful model somewhat analogous to localized gonococcal infection in man.

Animals↗
PubMed1973

Quantitative determination of antibody to gonococcal pili. Changes in antibody levels with gonococcal infection.

Gonococcal pili, pure by the criteria of electron microscopic examination and polyacrylamide gel electrophoresis in sodium dodecyl sulfate, have been prepared by repeated cycles of precipitation with 0.1 M MgCl(2), followed by dissolution in 0.01 M Tris pH 8, 0.01 M NaN(3). Using a fluorescein-conjugated antibody prepared to pili from a single strain, pilar antigen(s) was found to be present in each of 18 strains of gonococci tested, and absent from strains of pilated meningococci, nonpathogenic Neisseria sp., and Escherichia coli. Purified pili, labeled with (125)I were used in an antigen binding assay to quantitatively measure antibody to pili in rabbit sera and in 561 human sera. The range of antibody activity for 133 persons unlikely to have experienced gonorrhea was 0.1-1.6 mug/ml with a geometric mean of 0.5 mug/ml. This geometric mean antibody activity was significantly lower than the geometric mean for asymptomatically infected males (1.0 mug/ml, P < 0.002), males with symptomatic gonococcal anterior urethritis (1.6 mug/ml, P < 0.001), or asymptomatically infected females (4.2 mug/ml, P < 0.001). Antibody appeared in elevated levels (> 1.6 mug/ml) 2-3 wk after infection and returned toward control levels 1 or more months after treatment. Antibody levels higher than 1.6 mug/ml were found in 26 (50%) of 52 males with gonococcal anterior urethritis, in 10 (33%) of 30 males with asymptomatic urethral infection and in 50 (89%) of 56 asymptomatically infected females. In a high-risk group of 103 females for whom culture results and antibody to pili were compared, 58 (57%) had elevated antibody levels to pili and 86% of the infected females were within this seropositive group. The antigen binding assay may provide a means to detect asymptomatic gonococcal infection in women.

Adolescent↗
PubMed1973

A controlled field trial of a serogroup A meningococcal polysaccharide vaccine.

A controlled field trial of a serogroup A meningococcal polysaccharide vaccine was conducted at three locations in Egypt during the winter cerebrospinal meningitis (CSM) season of 1971-72. The study population consisted of schoolchildren 6-15 years of age. No cases of serogroup A meningococcal CSM occurred in the group of students vaccinated with the test vaccine whereas 8 cases occurred in the control group vaccinated with tetanus toxoid, and 151 cases occurred in an unvaccinated contrast group. The case rate was significantly different between the test and control groups as well as between the test and contrast groups but was similar between the control and contrast groups. The previously demonstrated safety of the vaccine was confirmed. A significant serological response was elicited in the majority of the vaccinated students.

Adolescent↗
PubMed1972

Enteric bacteria cross-reactive with Neisseria meningitidis groups A and C and Diplococcus pneumoniae types I and 3.

Enteric bacteria of 1,335 individual strains were studied for serological cross-reactions with Neisseria meningitidis groups A and C and Diplococcus pneumoniae types I and III. Enterobacterial antigens cross-reactive with the capsular polysaccharides of these four bacteria were found. Bacteria cross-reactive with noncapsular antigens of meningococci and pneumococci were also observed. Since some enteric bacteria possess antigens with serological specificities similar to those of meningococci, the possibility that enteric bacteria cross-reactive with meningococcal antigens provide an antigenic stimulus for the observed age-related "natural" immunity to this pathogen is discussed.

Animals↗