Comparison of three rapid methods for detection of antibodies to streptolysin O and DNase B

Hostetler, C L; Sawyer, Kjell; Nachamkin, Irving

doi:10.1128/jcm.26.7.1406-1408.1988

Cited by 9 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DNases A and D were secreted by about 25 to 30% of the isolates tested (31,44,46). The production of DNase B by virtually all GAS strains and the frequent specific antibody response of GAS-infected humans to this antigen prompted investigators to use measurements of anti-DNase B antibody titers as a standard technique to screen for GAS infections (13,16,20,32).…”

mentioning

confidence: 99%

Molecular characterization of a major serotype M49 group A streptococcal DNase gene (sdaD)

et al. 1996

View full text Add to dashboard Cite

Group A streptococci (GAS) express up to four types of secreted DNases. Although GAS infections are correlated with the production of anti-DNase B antibodies, the roles of DNases in the pathogenesis of GAS infections remain unclear. From a lambda library of serotype M49 strain CS101 GAS genome, a 2,147-bp fragment expressing DNase activity on an indicator agar was identified and sequenced. One 1,155-bp open reading frame (ORF) was identified in this fragment. This ORF was found to be 48% identical on the amino acid level to group C streptococcal DNase (Sdc). The regions of highest homology corresponded to amino acid residues that were also identified as part of the active site in staphylococcal nuclease. Transcription analysis revealed a specific 1.3-kb mRNA, which corresponded to the size predicted by the promoter and transcription termination signature sequences and indicated a monocistronic mode of transcription. Allelic replacement of the ORF rendered a M49 mutant devoid of extracellular DNase activity when cultured on indicator agar. Virulence parameters such as resistance to phagocytosis were not affected by the mutation. The sda gene was cloned and expressed in Escherichia coli as a thioredoxin fusion. By performing Ouchterlony immunodiffusion on the recombinant protein and by using protein preparations from culture supernatants of wild-type bacteria and the DNase mutant, the results of immunoreactivity with DNase type-specific polyclonal rabbit antisera classified the DNase as a type D enzyme. Fifty percent of patients with sera exhibiting high titers of antistreptolysin or anti-DNase B antibodies also had SdaD-reactive antibodies in comparison with <10% of serologically normal controls. While the value of recombinant SdaD for diagnostic purposes needs to be clarified, the isogenic DNase mutant pair of M49 should allow the significance of GAS DNase D as a bacterial virulence factor to be determined.

show abstract

mentioning

confidence: 99%

Molecular characterization of a major serotype M49 group A streptococcal DNase gene (sdaD)

et al. 1996

View full text Add to dashboard Cite

show abstract

“…The Leap Strep (Organon Teknika, Malvern, Pa.) is a liposome-enhanced LA test which measures not only ASO but anti-DNase B antibodies as well. However, when compared with the standard neutralization assay for ASO antibodies, the Leap Strep was judged to have insufficient sensitivity and could not be recommended as a useful test for screening for ASO antibodies (8,9). The Check-Spectra (Diagniostic Technology, Hauppauge, N.Y.) is a LA test for measuring ASO antibodies that was also found to be too insensitive to be useful in screening serum specimens (9).…”

Section: Resultsmentioning

confidence: 99%

“…However, when compared with the standard neutralization assay for ASO antibodies, the Leap Strep was judged to have insufficient sensitivity and could not be recommended as a useful test for screening for ASO antibodies (8,9). The Check-Spectra (Diagniostic Technology, Hauppauge, N.Y.) is a LA test for measuring ASO antibodies that was also found to be too insensitive to be useful in screening serum specimens (9). The Mercia ASL Latex Kit (Mercia Diagnostic Ltd, Great Britain) is another LA test for determining ASO antibody titers (2).…”

Section: Resultsmentioning

confidence: 99%

Evaluation of a new latex agglutination test for detection of streptolysin O antibodies

1990

View full text Add to dashboard Cite

Acuteand convalescent-phase serum specimens were collected from 50 patients with group A streptococcal pharyngitis. The anti-streptolysin O (ASO) titer for each serum specimen was determined by using both the standard neutralization assay and the latex agglutination (LA) test (Rheumagen ASO; Biokit Inc., New Britain, Conn.). When the ASO titers derived by the two methods were compared, the correlation coefficient was 0.93. When the ability of the LA test to demonstrate a significant ASO titer rise (.2 dilutions) was compared with that of the standard neutralization assay, the LA test had a sensitivity of 91%, a specificity of 86%, a positive predictive value of 83%, and a negative predictive value of 92%. Triplicate LA test determinations were performed on a subset of 31 serum specimens, and for 29 (94%), the repeated ASO titers were all within 1 dilution of each other; the width of the 95% confidence interval for the triplicate measurements of each serum specimen was ±32.8 IU. We found the Rheumagen ASO to be a simple, rapid LA procedure for measuring ASO titers that produces results that are highly reproducible, show little lot-to-lot variability, and are comparable to the ASO titers obtained with the standard neutralization assay.

show abstract

“…Group A streptococci produce four antigenically distinct DNases (A, B, C, and D) capable of degrading DNA. Whether any or all of these are important as virulence factors is unknown (202), although they are produced during an infection because anti-DNase antibodies have been used as a diagnostic tool (203,204). A gene (sdaD) identified as a DNase gene from S. pyogenes was reported to be similar to the group C streptococcal DNase, with the highest level of homology to the portion of the protein suggested to be the active site (205).…”

Section: Dnasesmentioning

confidence: 99%

Virulence factors of the group A streptococci and genes that regulate their expression

Hynes¹

2004

Front Biosci

View full text Add to dashboard Cite

Group A streptococci produce a wide variety of extracellular (cell-associated and released) virulence factors. The function of these factors varies and includes roles in adhesion, spreading, tissue destruction, immune system evasion, and cell toxicity. How these factors are regulated with regard to one another is important for this organism s ability to bring about the variety of diseases this microbe is capable of causing. Therefore, along with the multitude of virulence factors, there are a number of regulatory systems that regulate, either directly or indirectly, the production of these factors and therefore influence the pathogenesis of group A streptococcal infections.

show abstract

Comparison of three rapid methods for detection of antibodies to streptolysin O and DNase B

Cited by 9 publications

References 9 publications

Molecular characterization of a major serotype M49 group A streptococcal DNase gene (sdaD)

Molecular characterization of a major serotype M49 group A streptococcal DNase gene (sdaD)

Evaluation of a new latex agglutination test for detection of streptolysin O antibodies

Virulence factors of the group A streptococci and genes that regulate their expression

Contact Info

Product

Resources

About