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M D Moody

Publications and source records attributed to M D Moody.

36 records · Page 2Linked to original sources
PubMed1970

Acid-precipitated M protein compared with a column-eluted M protein preparation from type 12, group A Streptococci.

An M protein preparation of group A streptococci, precipitated with 0.03 m sodium acetate buffer (pH 4.0) was compared with a column-eluted M protein preparation. Absorption spectra and methyl pentose content were similar in both preparations. Acrylamide gel electrophoresis patterns were different. Gel diffusion demonstrated two lines of fusion in the preparations. More antigens could be demonstrated in both preparations by using immunoelectrophoresis. Neither the pH 4 precipitate nor the column-eluted preparation appeared to be a pure M protein preparation.

Antigens↗
PubMed1970

Comparison of antistreptolysin O latex screening test with the antistreptolysin O hemolytic test.

This report describes a comparison of the Behringwerke antistreptolysin O (ASO) latex screening test with the ASO hemolytic test. Agreement between the two tests was poor when Difco streptolysin O (SLO) reagent was employed in the hemolytic test; approximately 34% of the sera with ASO titers in the normal range of the hemolytic test gave false-positive latex test reactions. However, the percentage of false-positive latex test reactions was only 5% when Behringwerke SLO reagent was used in the hemolytic test. An assay of the Difco and Behringwerke SLO reagents against an ASO standard indicated that the Difco SLO reagent was more potent than the Behringwerke SLO reagent. The lack of agreement between the Behringwerke latex test and the hemolytic test using Difco SLO reagent is attributed to the potency of the SLO reagents.

Antistreptolysin↗
PubMed1970

Antigenic variation in group A streptococci: types 11 and 9.

A strain of group A Streptococcus which was virulent but M-nontypable was isolated from patients in a hospital nursery during an epidemic. This strain, Boston 11, reacted in T-agglutination tests with antisera for types 9 and 11, an unusual combination. A comparison of this strain with Lancefield's M-11 strain (NCDC SS-721) and Alabama 11 (Provisional 61) revealed three serologically related but distinct strains. Antiserum produced with the Boston 11 strain exhibited similar reactivity with all three "11" strains as well as with M-9 (SS-501) as demonstrated in precipitin tests. Immunodiffusion studies indicated that the Boston 11 antigen was partially identical with the M-11 and M-9 strains and shared at least one antigen with the Alabama 11 strain. The Boston 11 antiserum could be made specific for precipitin tests, but bactericidal activity for the Alabama 11, M-11, and Boston 11 strains was essentially negative.

Agglutination Tests↗
PubMed1970

Presumptive identification of group D streptococci: the bile-esculin test.

Six tests commonly used for the presumptive identification of group D streptococci were evaluated. Strains tested included 282 group D streptococci and 366 non-group D. Ratios of percentages of group D to non-group D strains which gave positive reactions for each test are as follows: bile-esculin, 100:2; salt tolerance, 88:24; heat tolerance, 100:80; SF broth, 86:1; KF broth, 99:40; and methylene blue milk reduction, 90:17. These data indicate that the bile-esculin test provided a reliable means of identifying group D streptococci and differentiating them from non-group D streptococci. Methodology for reading and interpreting positive reactions and time of incubation of the bile-esculin medium was defined. Evidence of the need for standardization of salt and heat-tolerance tests was obtained.

Agar↗
PubMed1969

Acrylamide gel electrophoresis of group A streptococcal cell walls.

Patterns obtained by acrylamide gel electrophoresis of group A streptococcal cell walls were characteristic for M types 1, 2, 3, 4, and 5, respectively. Best results were obtained with cell walls which had been solubilized with a phenol-acetic acid-water mixture. The method will make it possible to compare group A streptococci of epidemiological and clinical significance and to separate components for more critical analysis.

Bacterial Proteins↗
PubMed1969

Identification of group A streptococci by direct fluorometry.

A simple direct fluorometric method for rapid identification of group A streptococci is described. The method permits the detection of the organism in mixed cultures without the aid of a microscope and is amenable to automated processing of specimens. Experience with the indirect fluorometric method revealed that nontrypsinized cells from a 10-fold dilution of overnight broth cultures could be stained with uniform brilliance with fluorescent antibody (1:15 dilution) and that fluorescent antibody dissociated from such cells at 55 C for 20 min gave serologically specific fluorometric values. With this information, it was possible to develop a simpler fluorometric test which gave results comparable to those obtained by conventional cultural-precipitin grouping techniques. In the direct test described, cultures from throat swabs were incubated overnight, and cells from a 10-fold dilution were stained with specific fluorescent antibody (1:50 dilution) and then rinsed. The stained specimens were transferred to a continuous-filter paper strip (Whatman 3 MM) and read serially in a Turner 110 fluorometer with Corning 5840 and Wratten 2A filters in place. The reagents used required careful standardization and testing to assure that fluorometric readings above a specified value would be indicative of the presence of group A streptococci.

Automation↗
PubMed1969

Detection of group A streptococci in throat swabs by direct fluorometry.

A direct fluorometric test for the rapid detection of group A streptococci from throat swabs was compared with the microscopic fluorescent-antibody test. Formalinized throat swab cultures (490) were examined by the two methods, and the results agreed on 84% of the specimens. In another comparison, 15-hr broth cultures of 103 freshly taken throat swabs were tested by both methods. Of the specimens tested, 101 (98%) were either positive or negative by both methods. In all cases, the latter results correlated with the demonstration of presence or absence of group A streptococci in the specimens by cultural isolation and precipitin grouping tests. It may be feasible to use the direct fluorometric test in a diagnostic laboratory as described or possibly to adapt it for automatic processing of throat swab cultures.

Bacteriological Techniques↗
PubMed1969

Effect of incubation temperature on T-agglutination typing of Streptococcus pyogenes.

The temperature of incubation affected the typability of beta-hemolytic group A streptococci by T-agglutination tests. When strains could not be typed after routine incubation at 30 C, they were incubated at 22 to 25 C, and nearly a 10% increase in typability was achieved. The clinical source of the strains was related to their typability. Incubation at the lower temperature was required for successful typing of higher percentages of strains from the skin and other clinical sources than from the throat. Sixty per cent of the skin strains were represented by six serotypes. Of these, 53% of the strains required incubation at 22 to 25 C before they could be typed.

Agglutination Tests↗
PubMed1969

Micro test for streptococcal anti-deoxyribonuclease B.

A methyl green decolorization micro test for the determination of streptococcal anti-deoxyribonuclease B titers in serum is described. The micro test was compared with an alcohol precipitation macro test on 112 human sera. The anti-deoxyribonuclease B titers agreed within one dilution step for 85.7% of the 112 sera examined by both techniques. Both tests were about equal in the detection of titers above the upper limits of normal. The micro test requires smaller amounts of reagents and fewer man-hours to perform than the macro test. This translates into lower cost per test and more tests per man-hour.

Antibodies↗
PubMed1969

Serological relationships of type I antigens of group B streptococci.

Some of the complex antigenic relationships of type I group B streptococci from various clinical sources were defined by means of immunodiffusion, absorption, and precipitin tests. Three predominant types are described: Ia, Ib, and Ii. Methods for preparing antisera for differentiating type I strains are presented.

Absorption↗
PubMed1968

Effect of type of red blood cells on antistreptolysin O titer.

Antistreptolysin O (ASO) titers were determined on 117 human sera with rabbit, human, and sheep red blood cells (RBC) as the indicator system in the ASO tube test. The titers of 65% of the sera were one dilution step higher when a 5% suspension of sheep RBC was used instead of a 5% suspension of rabbit RBC. Titers were one dilution step higher in 42.7% of the sera when a 5% suspension of human RBC was used instead of a 5% suspension of rabbit RBC. The best comparability of titers was between a 5% suspension of human RBC and a 2.5% suspension of sheep RBC.

ABO Blood-Group System↗
PubMed1968

Production of streptococcal M-typing antisera. I. Antigenic response in different breeds of rabbits.

M-antigens of seven M-types of group A streptococci were used to compare antigenic response in six breeds of rabbits: New Zealand White, New Zealand Red, Dutch, Googy, California, and Palomino. No appreciable differences among breeds were demonstrated. M-types used for immunization varied considerably in their ability to evoke a response of an antibody which met rigid criteria for streptococcal M-typing antisera. The importance of the injection and bleeding schedule and absorption conditions for preparing type-specific absorbed antisera were demonstrated. Evaluating and processing sera from individual animals at an optimal time rather than using pooled sera enhanced the possibilities for preparing satisfactory type-specific antisera.

Animals↗