Evaluation of an improved rapid coagglutination method for the serological grouping of beta-hemolytic streptococci D A N I E LV. L I M ,ROSELLAD. S M I T HA, N D SUSAN DAY Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by University of Auckland on 12/05/14 For personal use only.
I)ci)o'.rj~lc,~r(c?l'Hiolog.v, Utiil~rrrir.vc!f'Sor~/lr Floricltr, Ttr/,ipo, F L , U.S.A. 33620 Accepted September 27. 1978
L I M . D. V . , R. D. S M I T H and , S . DAY. 1979. Evaluation of an imp~.ovedrapid coagglutin;~tion method for the serological grouping of beta-hemolytic st~.eptococci.Can. J . Microbiol. 25: 40-43. Grouping of hc.t;~-hemolytichtrcptococci was pc~'fo~.mctl with the Phatlcb;lctNSII-cptococcus Test. a co;lgglurination method, and the results compared with serological grouping by the standal-d Lancetield precipitin rncthotl. O f 171 clinic21l hpecimens examined. 169 (98.8%) were grouped col.~.ectlyby the Phaclebact" Tcst after24 h ofcontinuous growth in Tocltl-Hcwitt broth, I n :I p;li.ullel st~icly.96.9% of specimens that grew after only 3 h of incubation in broth were grouped correctly by the coagglutination method. In both studies, the accuracy of the coagglutination test was increased significantly by elimination of m ~ ~ l t i p l e - a g g l ~ ~ t i n nreactions tion through centrifugation ofcultu~.csand utiliz;~tionof the supernatant fluicl in the P h a t l c b ~ ~ cTcst. t" L I M , D. V.. R. D. Sh.117'~el S. DAY. 1979. Ev;rluation of an improved ~ x p i dcongglutin:~tion method for the serological grouping of beta-hemolytic streptococci. Can. J . Microbiol. 25: 40-43. Le regroupernent des streptocoques beta-hemolytiques a ete rialisi par line methode de co;~gglutinz~tion: "Ph;tdebactK Streptococcus Test," ces resultats o n t i t 2 compares ;I ceux obtenus par le groupement se~.ologique utilisnnt la classiquc methode de la precipitine de Lancefield. Sur Ies 171 specimens clinique examines. I69 (98.8%) ont e t e regroupescorrectement par Ie test "Ph;~Jeh;~ct","et c e , ap1'6s23 h tle c u l t l ~ ~continue .e dans le bouillon tle Totlcl-Hewitt. Pzirallelernent 96.9%des specimens qui se sont developpis apses4 h d'incub;~tiondans le bouillon ont ete correctement 1.egroupes pal. la mithode d e coagglutination. Dans ces deux etudes. 1 ; ~ precision du test de coagglutinz~tionest ;tugmentee de firson significative par I'elimination des ~renctionsd'agglutinution multiple gl.Gce i~ une centrifugation des c u l t ~ ~ r eet, s , B I'utilisa~iondu surn;lge:int pour le test "Ph;~tleh;~ct "." [Traduit par le journal]
Introduction The classical method for sel.ological grouping of beta-henlolytic streptococci involves precipitation of group antigens with group-specific antisera (Lancefield 1933). Although the Lancefield precipitin method is accul-ate and I-eliuble, the technique is time-consuming and the I-esults often are difficult to interpret. Recently. a coagglutination method was developed to group st~'eptococci(Christensen r t 01. 1973). The procedure involves reaction of streptococcal group antigens with group-specific antibodies bound to the protein A component of the cell wall of dead staphylococci. The method is rapid, accurate, and easy to interpret and has been evaluated by several investigators. Hahn and Nyberg (1976) observed in their study that 98.7% of streptococci could be grouped torrectly by this method after overnight growth of the bacteria in an enriched broth. Finch and Phillips (1977) also found a high degree of correlation
(92.7%) in a comparison of streptococcal grouping by standard accepted methods and by the coagglutination technique. In a more recent investigation, Rosner (1977) was able to grow clinical strains of beta-hemolytic streptococci in ToddHewitt broth after only 4 h of incubation and cor- ~ the S Phadebact!!! rectly ~ I - O L I P119 of 132 C L I ~ ~ L I Iby Test. Many of Rosner's strains showed multiple coagglutination I-eactionsand, therefore. could not be grouped col'rectly until after an additional period of incubation. Although such multiple reactions sometimes can be distinguished on the basis of intensities observed in the different coagglutination reactions, interpretations of the results can vary from laboratol-y to laboratory. The elimination of such multiple reactions would increase the accu' ~ by I-educingthe need racy of the P h a d e b a ~ tTest for such interpretations. In this report, we evaluate the coagglutination method with streptococci and other bacteria grown for 4 h and for 24 h in an enriched broth. We also
0008-4 166I791010040-04%01.0010
01979 N;itional Kesearch Council of Cnn;~dz~/Conseil national d e recherche5 d ~ Canada r
TAULI:I . Comparison of streptococcal g~.oupingby thc Lancefield precipitin mctliocl and by thc 24-11 coagglutination methoti
No, o f stly,ins grouped by the Lanccficld method
Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by University of Auckland on 12/05/14 For personal use only.
Group
No. of strains corl.cctly grouped by the coagglutination niethod with: 23-h culture"
73-h c ~ l l t ~ + ~re supernatant fluid
88 (94.6";) 3 s (1 OO.O"';,) I (l2.5!!
I)ci)o'.rj~lc,~r(c?l'Hiolog.v, Utiil~rrrir.vc!f'Sor~/lr Floricltr, Ttr/,ipo, F L , U.S.A. 33620 Accepted September 27. 1978
L I M . D. V . , R. D. S M I T H and , S . DAY. 1979. Evaluation of an imp~.ovedrapid coagglutin;~tion method for the serological grouping of beta-hemolytic st~.eptococci.Can. J . Microbiol. 25: 40-43. Grouping of hc.t;~-hemolytichtrcptococci was pc~'fo~.mctl with the Phatlcb;lctNSII-cptococcus Test. a co;lgglurination method, and the results compared with serological grouping by the standal-d Lancetield precipitin rncthotl. O f 171 clinic21l hpecimens examined. 169 (98.8%) were grouped col.~.ectlyby the Phaclebact" Tcst after24 h ofcontinuous growth in Tocltl-Hcwitt broth, I n :I p;li.ullel st~icly.96.9% of specimens that grew after only 3 h of incubation in broth were grouped correctly by the coagglutination method. In both studies, the accuracy of the coagglutination test was increased significantly by elimination of m ~ ~ l t i p l e - a g g l ~ ~ t i n nreactions tion through centrifugation ofcultu~.csand utiliz;~tionof the supernatant fluicl in the P h a t l c b ~ ~ cTcst. t" L I M , D. V.. R. D. Sh.117'~el S. DAY. 1979. Ev;rluation of an improved ~ x p i dcongglutin:~tion method for the serological grouping of beta-hemolytic streptococci. Can. J . Microbiol. 25: 40-43. Le regroupernent des streptocoques beta-hemolytiques a ete rialisi par line methode de co;~gglutinz~tion: "Ph;tdebactK Streptococcus Test," ces resultats o n t i t 2 compares ;I ceux obtenus par le groupement se~.ologique utilisnnt la classiquc methode de la precipitine de Lancefield. Sur Ies 171 specimens clinique examines. I69 (98.8%) ont e t e regroupescorrectement par Ie test "Ph;~Jeh;~ct","et c e , ap1'6s23 h tle c u l t l ~ ~continue .e dans le bouillon tle Totlcl-Hewitt. Pzirallelernent 96.9%des specimens qui se sont developpis apses4 h d'incub;~tiondans le bouillon ont ete correctement 1.egroupes pal. la mithode d e coagglutination. Dans ces deux etudes. 1 ; ~ precision du test de coagglutinz~tionest ;tugmentee de firson significative par I'elimination des ~renctionsd'agglutinution multiple gl.Gce i~ une centrifugation des c u l t ~ ~ r eet, s , B I'utilisa~iondu surn;lge:int pour le test "Ph;~tleh;~ct "." [Traduit par le journal]
Introduction The classical method for sel.ological grouping of beta-henlolytic streptococci involves precipitation of group antigens with group-specific antisera (Lancefield 1933). Although the Lancefield precipitin method is accul-ate and I-eliuble, the technique is time-consuming and the I-esults often are difficult to interpret. Recently. a coagglutination method was developed to group st~'eptococci(Christensen r t 01. 1973). The procedure involves reaction of streptococcal group antigens with group-specific antibodies bound to the protein A component of the cell wall of dead staphylococci. The method is rapid, accurate, and easy to interpret and has been evaluated by several investigators. Hahn and Nyberg (1976) observed in their study that 98.7% of streptococci could be grouped torrectly by this method after overnight growth of the bacteria in an enriched broth. Finch and Phillips (1977) also found a high degree of correlation
(92.7%) in a comparison of streptococcal grouping by standard accepted methods and by the coagglutination technique. In a more recent investigation, Rosner (1977) was able to grow clinical strains of beta-hemolytic streptococci in ToddHewitt broth after only 4 h of incubation and cor- ~ the S Phadebact!!! rectly ~ I - O L I P119 of 132 C L I ~ ~ L I Iby Test. Many of Rosner's strains showed multiple coagglutination I-eactionsand, therefore. could not be grouped col'rectly until after an additional period of incubation. Although such multiple reactions sometimes can be distinguished on the basis of intensities observed in the different coagglutination reactions, interpretations of the results can vary from laboratol-y to laboratory. The elimination of such multiple reactions would increase the accu' ~ by I-educingthe need racy of the P h a d e b a ~ tTest for such interpretations. In this report, we evaluate the coagglutination method with streptococci and other bacteria grown for 4 h and for 24 h in an enriched broth. We also
0008-4 166I791010040-04%01.0010
01979 N;itional Kesearch Council of Cnn;~dz~/Conseil national d e recherche5 d ~ Canada r
TAULI:I . Comparison of streptococcal g~.oupingby thc Lancefield precipitin mctliocl and by thc 24-11 coagglutination methoti
No, o f stly,ins grouped by the Lanccficld method
Can. J. Microbiol. Downloaded from www.nrcresearchpress.com by University of Auckland on 12/05/14 For personal use only.
Group
No. of strains corl.cctly grouped by the coagglutination niethod with: 23-h culture"
73-h c ~ l l t ~ + ~re supernatant fluid
88 (94.6";) 3 s (1 OO.O"';,) I (l2.5!!
