Serum inhibition of streptococcal diphosphopyridine nucleotidase in uncomplicated streptococcal pharyngitis and in rheumatic fever

Identification and immunogenicity of group A Streptococcus culture supernatant proteins

Extracellular proteins made by group A Streptococcus (GAS) play critical roles in the pathogenesis of human infections caused by this bacterium. Although many extracellular GAS proteins have been identified and characterized, there has been no systematic analysis of culture supernatant proteins. Proteins present in the culture supernatant of strains of serotype M1 (MGAS 5005) and M3 (MGAS 315) mutants lacking production of the major extracellular cysteine protease were separated by two-dimensional gel electrophoresis and identified by amino-terminal amino acid sequencing and interrogation of available databases, including a serotype M1 genome sequence. In the aggregate, amino-terminal amino acid sequence data for 66 protein spots were generated, 53 unique sequences were obtained, and 44 distinct proteins were identified. Sixteen of the 44 proteins had apparent secretion signal sequences and 27 proteins did not. Eight of the 16 proteins with apparent secretion signal sequences have not been previously described for GAS. Antibodies against most of the apparently secreted proteins were present in sera from mice infected subcutaneously with MGAS 5005 or MGAS 315. Humans with documented GAS infections (pharyngitis, acute rheumatic fever, and severe invasive disease) also had serum antibodies reacting with many of the apparently secreted proteins, indicating that they were synthesized in the course of GAS-human interaction. The genes encoding four of the eight previously undescribed and apparently secreted culture supernatant proteins were cloned, and the proteins were overexpressed in Escherichia coli. Western blot analysis with these recombinant proteins and sera from GAS-infected mice and humans confirmed the immunogenicity of these proteins. Taken together, the data provide new information about the molecular aspects of GAS-host interactions.

NAD(+)-glycohydrolase productivity of haemolytic streptococci assayed by a simple fluorescent method and its relation to T serotype

The ability of haemolytic streptococci to produce NAD(+)-glycohydrolase was investigated by a fluorescent assay. Enzyme production was found in 31 (91%) of 34 group A, 17 (61%) of 28 group C and eight (27%) of 30 group G isolates. The high producers were found in 22 (65%) of group A, one (4%) of group C and none of group G isolates. The high producers of the group A isolates belonged to T-1, T-3, T-4 or T-12 serotype. These results suggest that NAD(+)-glycohydrolase productivity of streptococci is closely related to specific Lancefield's groups or T serotypes.

Enzyme-linked immunosorbent assay for anti-streptococcal protoplast membrane antibodies

An enzyme-linked immunosorbent assay is described for the quantitative determination of circulating antibodies to streptococcal protoplast membranes (SPM) in human sera. The assay was used to study the prevalence of antibodies to SPM of M types 6 and 12 Streptococcus pyogenes in sera from 55 patients with recent streptococcal infection, and 30 normal individuals without clinical evidence of streptococcal infection. No correlation was found between levels of anti-SPM antibodies and ASO titres. However, in serial serum samples from one patient with uncomplicated streptococcal sore throat, it was possible to demonstrate that the increase in the level of anti-SPM antibody paralleled the rise in ASO titre. The anti-SPM antibody level and the ASO titre in this patient persisted throughout a six-month period of follow-up.

The antistreptococcal immune responses in children with acute rheumatic fever in Kuwait

The antistreptococcal immune responses in 130 children with Acute Rheumatic Fever (ARF), seen in Kuwait, over a period of three years, are presented. The ages of children ranged between three to 13 years. One hundred and three presented in initial attacks while 27 presented in recurrences. The geometric mean of antistreptolysin 'O' (ASO) and antihyalurodinase (AH) titres for all patients were 488 Todd Units and 595 units, respectively. In children under the age of eight years, but not above this age, the geometric mean of ASO titres was significantly higher in children with carditis than in those without carditis (P less than 0.01); there was no significant difference in AH titres between the two groups. Analysis of the Geometric Mean Titres (GMT) of both antibodies in relation to other variables is also presented.

Application of a new method for detecting streptococcal nicotinamide adenine dinucleotide glycohydrolase to various M types of Streptoccus pyogenes

The production of extracellular nicotinamide adenine dinucleotide glycohydrolase (NADase) by Streptococcus pyogenes can easily be demonstrated using the fluorescence of nicotinamide adenine dinucleotide in ultraviolet light occurring on addition of strong alkali. The new method described here uses microtiter plates and can be read with the naked eye. It permits the screening of large numbers of strains in a short time and with minimal amounts of reagents. The sensitivity of the new method proved to be good in comparison with the bisulfite spectrophotometric method. Culture supernatants of 177 group A streptococci were tested for NADase production by the microtiter fluorescence method. We could confirm former findings that strains within a certain M type of S. pyogenes are usually either producers or nonproducers of the enzyme. The usefulness of the test for screening of streptococcal NADase production is discussed.

Use of bisulfite in the streptococcal anti-nicotinamide adenine dinucleotidase test

A major drawback in the performance of the streptococcal anti-nicotinamide adenine dinucleotidase test on a large scale has been the hazard involved in the use of cyanide in assaying nicotinamide adenine dinucleotide. The use of bisulfite instead of cyanide in the performance of this test was investigated. The assays obtained with bisulfite parallel closely those obtained with cyanide, and justify the replacement of cyanide by the safer bisulfite reagent.

SOME CHARACTERISTICS OF STREPTOCOCCAL NICOTINAMIDE ADENINE DINUCLEOTIDASE AND STREPTOLYSIN O

Pentz, E. Irene (Northwestern University School of Medicine, Chicago, Ill.), Eva Kot, and J. J. Ferretti. Some characteristics of streptococcal nicotinamide adenine dinucleotidase and streptolysin O. J. Bacteriol. 88:497-508. 1964.-Nicotinamide adenine dinucleotidase produced by Streptococcus pyogenes strain C203U, grown in Todd-Hewitt broth (Difco), was recovered from diethylaminoethyl-cellulose columns free from streptolysin O. It contained a trace of deoxyribonuclease. The elution peak of nicotinamide adenine dinucleotidase was fairly symmetrical; when it was treated with dinitrofluorobenzene (DNFB) and chromatogrammed on paper in three different solvent systems, only one yellow spot was obtained. Examination of the enzyme in an ultracentrifuge presented no moving boundary. The pore size of two different widths of Visking casing was estimated by dialyzing proteins or peptides of known molecular weight and testing the dialysate for their appearance. The casing which allowed a molecule of 2,500 molecular weight to pass, but not one of 3,000 molecular weight, retained the nicotinamide adenine dinucleotidase. A fragment having no nicotinamide adenine dinucleotidase activity did pass through this casing, however, but was retained by the second casing which retained molecules weighing 2,500. Amino acid analyses of three different nicotinamide adenine dinucleotidase preparations were remarkably similar, and were characterized by a high content of proline and glycine and a very low content of sulfur-containing amino acids. Examination by treatment with DNFB followed by hydrolysis for the presence of N-terminal amino acids ruled out all amino acids, with the possible exception of arginine. The combined evidence suggests that its molecular weight is between 2,500 and 20,000. Some data are presented to illustrate the irreversible instability of streptolysin O; amino acid analyses for three separate preparations of high activity indicate a very low content of sulfur-containing amino acids.