Journal of Antimicrobial Chemotherapy (1978) 4, 15-1918
Correspondence
influenzae
(1977).
185
Downloaded from http://jac.oxfordjournals.org/ at University of Manitoba on June 8, 2015
type e. Only one of these, belonging to type b and coming from a child with meningitis, was a P-lactamase producer. Our type b strains Sir, included 5 from children with meningitis, 5 In his Leading Article on this subject Howard from children with epiglottitis, 1 from a child (1977) mentions the results of a recent study with an abscess of the arm, 3 from conjunctival of the incidence of ampicillin resistance among swabs, 1 from an ear and 11 from respiratory Haemophilus influenzae strains isolated in 18 tract specimens. Howard suggested that the laboratories in England and Scotland between 9% (3 out of 32) incidence of P-lactamase February and April 1977. Our findings in production among the type b strains in his series was in conformity withfiguresfrom the Oxford may be of interest to your readers. For some years all haemophilus isolates in U.S.A. suggesting frequences of the order of this laboratory have been identified to species 10%. Our own very small series provides no level, and all those considered to be H. support for the suggestion that P-lactamase influenzae have been tested to see whether they production is commoner among type b strains form the iridescent colonies typical of capsu- than among non-capsulated strains. lated strains and have been typed if they do so. D.C.TURK Since the middle of January 1976 all H. Department of Bacteriology and influenzae strains have also been tested for Regional Public Health Laboratory, P-lactamase production. At first we used for The Radcliffe Infirmary, this purpose a modification of the Kjellander Oxford OX2 6HE, England and Myrbfich plate method essentially similar to that described by McGhie, Qarke, Johnson & Hutchison (1977). lAter we used in parallel with this the chromogenic cephaloReferences sporin substrate method (O'Callaghan, Morris Howard, A. J. Ampicillin resistance in HaemoKirby & Shingler, 1972), and more recently philus influenzae. Journal of Antimicrobial we have used our own rapid paper-strip Chemotherapy 3: 535-7 (1977). method (Slack, Wheldon & Turk, 1977). We Kjellander, J. & Myrbach, K. E. A simple test for penicillinase production (Abstract). Ada Pathohave found each of these methods a reliable logica et Microbiobgica Scanduumca 61: 494 means of detecting P-lactamase production. (1964). By the end of November 1977 we had tested a total of 699 strains of H. influenzae isolated McGhie, D., Clarke, P. D., Johnson, T. & Hutchison, J. G. P. Detection of beta lactamase from specimens submitted to this laboratory activity of Haemophilus influenzae. Journal of (excluding strains of H. influenzae sent here Clinical Pathology 30: 585-7 (1977). from other laboratories for confirmation of O'Callaghan, C. H., Morris, A., Kirby, S. M. & their identity and properties). Of the 661 non& Shingler, A. H. Novel method of detection of capsulated strains tested, most of them P-lactamases by using a chromogenic cephalocoming from respiratory tract specimens, 15 sporin substrate. Antimicrobial Agents and Chemotherapy 1: 283-8 (1972). (2-3%) were found to produce P-lactamase. This is an incidence rather higher than the 1-5 % Slack, M. P. E., Wheldon, D. B. & Turk, D. C. A rapid test for beta-lactamase production by quoted by Howard. The capsulated strains Haemophilus influenzae. The Lancet ii: 906 tested were 4 of type a, 26 of type b and 8 of AmpicilUn resistance in Haemophilia
Correspondence
influenzae
(1977).
185
Downloaded from http://jac.oxfordjournals.org/ at University of Manitoba on June 8, 2015
type e. Only one of these, belonging to type b and coming from a child with meningitis, was a P-lactamase producer. Our type b strains Sir, included 5 from children with meningitis, 5 In his Leading Article on this subject Howard from children with epiglottitis, 1 from a child (1977) mentions the results of a recent study with an abscess of the arm, 3 from conjunctival of the incidence of ampicillin resistance among swabs, 1 from an ear and 11 from respiratory Haemophilus influenzae strains isolated in 18 tract specimens. Howard suggested that the laboratories in England and Scotland between 9% (3 out of 32) incidence of P-lactamase February and April 1977. Our findings in production among the type b strains in his series was in conformity withfiguresfrom the Oxford may be of interest to your readers. For some years all haemophilus isolates in U.S.A. suggesting frequences of the order of this laboratory have been identified to species 10%. Our own very small series provides no level, and all those considered to be H. support for the suggestion that P-lactamase influenzae have been tested to see whether they production is commoner among type b strains form the iridescent colonies typical of capsu- than among non-capsulated strains. lated strains and have been typed if they do so. D.C.TURK Since the middle of January 1976 all H. Department of Bacteriology and influenzae strains have also been tested for Regional Public Health Laboratory, P-lactamase production. At first we used for The Radcliffe Infirmary, this purpose a modification of the Kjellander Oxford OX2 6HE, England and Myrbfich plate method essentially similar to that described by McGhie, Qarke, Johnson & Hutchison (1977). lAter we used in parallel with this the chromogenic cephaloReferences sporin substrate method (O'Callaghan, Morris Howard, A. J. Ampicillin resistance in HaemoKirby & Shingler, 1972), and more recently philus influenzae. Journal of Antimicrobial we have used our own rapid paper-strip Chemotherapy 3: 535-7 (1977). method (Slack, Wheldon & Turk, 1977). We Kjellander, J. & Myrbach, K. E. A simple test for penicillinase production (Abstract). Ada Pathohave found each of these methods a reliable logica et Microbiobgica Scanduumca 61: 494 means of detecting P-lactamase production. (1964). By the end of November 1977 we had tested a total of 699 strains of H. influenzae isolated McGhie, D., Clarke, P. D., Johnson, T. & Hutchison, J. G. P. Detection of beta lactamase from specimens submitted to this laboratory activity of Haemophilus influenzae. Journal of (excluding strains of H. influenzae sent here Clinical Pathology 30: 585-7 (1977). from other laboratories for confirmation of O'Callaghan, C. H., Morris, A., Kirby, S. M. & their identity and properties). Of the 661 non& Shingler, A. H. Novel method of detection of capsulated strains tested, most of them P-lactamases by using a chromogenic cephalocoming from respiratory tract specimens, 15 sporin substrate. Antimicrobial Agents and Chemotherapy 1: 283-8 (1972). (2-3%) were found to produce P-lactamase. This is an incidence rather higher than the 1-5 % Slack, M. P. E., Wheldon, D. B. & Turk, D. C. A rapid test for beta-lactamase production by quoted by Howard. The capsulated strains Haemophilus influenzae. The Lancet ii: 906 tested were 4 of type a, 26 of type b and 8 of AmpicilUn resistance in Haemophilia
