Cell Envelope of Neisseria gonorrhoeae : Outer Membrane and Peptidoglycan Composition of Penicillin-Sensitive and -Resistant Strains

Abstract

The cell envelope of Neisseria gonorrhoeae , colony type 4, was studied. Outer membrane was isolated by lysozyme and ethylenediaminetetraacetic acid treatment of plasmolyzed cells according to Wolf-Watz et al. (1973). The degree of purity of the membrane preparations was checked by electron microscopy. The membrane fraction obtained had a density of 1.25 g/cm 3 , was rich in phospholipase A and lysophospholipase, and contained only 10% of the total membrane activity of succinate dehydrogenase and d -lactate dehydrogenase. The outer membrane protein profile after sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed at least six major proteins. The predominating protein showed a molecular weight of 35,000. The lipopolysaccharide component was characterized by gas chromatography. The carbohydrates found were galactose, glucose, and glucosamine. d -Glycero- l -manno-heptose was present in very low amounts. Lipid A contained lauric acid, stearic acid, and β-hydroxy-myristic acid. About 20% of the fatty acids in the outer membrane was derived from lipid A. The phospholipids were characterized as phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. There was no evidence for a lipoprotein anchored to the peptidoglycan. The peptidoglycan of N. gonorrhoeae was of the chemotype I. The cell envelope of N. gonorrhoeae was found to be highly permeable to gentian violet. Cell envelopes of one penicillin-resistant and two penicillin-sensitive strains were compared. Only moderate differences in fatty acid composition were found.

The effect of iron starvation on the outer membrane protein composition of Neisseria gonorrhoeae

“…We have found that the use of 2% Sarkosyl to selectively remove cytoplasmic membrane proteins from total membrane preparations ofNeisseria genorrhoeae provides a rapid and reproducible method for extracting outer membrane proteins. The protein profile seen after SDS-polyacrylamide gel electrophoresis, as has been noted before [11 ], is directly comparable with that obtained by other methods [11][12][13].…”

THERMOSTABLE NEISSERIA GONORRHOEAE ANTIGENS EXAMINED BY A BACTERIAL AGGLUTINATION TEST

“…However, the results indicate that other thermostable antigens, probably of varying chemical nature, were also involved, as in agglutination by antibody of heat-treated cells of Pseudomonas aeruginosa observed by others (4). The data in the present study are in accordance with recent observations by others to the effect that the outer membrane of the cell envelope of gonococci contains several components with potential immunogenicity (7, 17). With the exception of the thermostable antigenic determinants of the endotoxin (9), the susceptibility to heat treatment of other envelope antigens of gonococci or their role in antibody-mediated agglutination of the bacteria is not known.…”

Membrane glycerophospholipid biosynthesis in Neisseria meningitidis and Neisseria gonorrhoeae: identification, characterization, and mutagenesis of a lysophosphatidic acid acyltransferase

“…The presence of alternative enzymatic pathways for glycerophospholipid synthesis in Neisseria is supported by our analysis of the glycerophospholipid profile and acyltransferase activity of the nlaA mutants. Previous studies (Sud and Feingold, 1975;Senff et aL, 1976;Beebe and Wlodkowski, 1976;Cacciapuoti et aL 1979;Wolf-Watz et aL, 1975) have shown that PE comprises 70-80% and PG 15-20% of the total membrane phospholipids in N. gonorrhoeae. Insertional inactivation of the nlaA genes in both meningococci and gonococci decreased the PE and PG content with a concomitant increase in the precursor LPA and in other, unidentified phospholipids.…”

“…Although the lipid composition of the Neisseriae spp. has been studied (Sud and Feingold, 1975;Senff etaL, 1976;Beebe and Wlodkowski, 1976;Cacciapuoti et al, 1979;Wolf-Watz et al, 1975), little is known regarding the genes involved in phospholipid biosynthesis. Our data document the presence of an LPA acyltransferase in the pathogenic Neisseria spp., which we have designated nlaA (neisserial LPA acyltransferase), and, more impor-tantly, they suggest that both gonococci and meningococci, unlike E. coil, can utilize alternative enzymes for the production of PA.…”