Abstract
In vitro studies evaluated methods for testing the susceptibility of Haemophilus influenzae to piperacillin-tazobactam combinations. Ampicillin-resistant beta-lactamase-nonproducing strains of H. influenzae may be presumed to be relatively resistant to combinations of piperacillin-tazobactam, even though they frequently appear to be susceptible by disk diffusion methods. Other ampicillin-resistant or -susceptible strains were predictably susceptible; i.e., 130 such strains gave zones of inhibition > or = 26 mm in diameter, and MICs for these strains were < or = 0.125/4.0 micrograms/ml (< or = 1.0/0.12 micrograms/ml when an 8:1 ratio was tested). A resistant category has yet to be defined. For quality control purposes, H. influenzae ATCC 49247 should give zones of inhibition 32 to 38 mm in diameter, and broth microdilution MICs should be 0.12/4.0 to 0.5/4.0 micrograms/ml.
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Selected References
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- Barry A. L., Fuchs P. C., Pfaller M. A. Susceptibilities of beta-lactamase-producing and -nonproducing ampicillin-resistant strains of Haemophilus influenzae to ceftibuten, cefaclor, cefuroxime, cefixime, cefotaxime, and amoxicillin-clavulanic acid. Antimicrob Agents Chemother. 1993 Jan;37(1):14–18. doi: 10.1128/aac.37.1.14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eliopoulos G. M., Klimm K., Ferraro M. J., Jacoby G. A., Moellering R. C., Jr Comparative in vitro activity of piperacillin combined with the beta-lactamase inhibitor tazobactam (YTR 830). Diagn Microbiol Infect Dis. 1989 Nov-Dec;12(6):481–488. doi: 10.1016/0732-8893(89)90082-5. [DOI] [PubMed] [Google Scholar]
- Gavan T. L., Jones R. N., Barry A. L., Fuchs P. C., Gerlach E. H., Matsen J. M., Reller L. B., Thornsberry C., Thrupp L. D. Quality control limits for ampicillin, carbenicillin, mezlocillin, and piperacillin disk diffusion susceptibility tests: a collaborative study. J Clin Microbiol. 1981 Jul;14(1):67–72. doi: 10.1128/jcm.14.1.67-72.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones R. N., Barry A. L. Studies to optimize the in vitro testing of piperacillin combined with tazobactam (YTR 830). Diagn Microbiol Infect Dis. 1989 Nov-Dec;12(6):495–510. doi: 10.1016/0732-8893(89)90084-9. [DOI] [PubMed] [Google Scholar]
- Jorgensen J. H., Doern G. V., Maher L. A., Howell A. W., Redding J. S. Antimicrobial resistance among respiratory isolates of Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae in the United States. Antimicrob Agents Chemother. 1990 Nov;34(11):2075–2080. doi: 10.1128/aac.34.11.2075. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jorgensen J. H., Redding J. S., Maher L. A., Howell A. W. Improved medium for antimicrobial susceptibility testing of Haemophilus influenzae. J Clin Microbiol. 1987 Nov;25(11):2105–2113. doi: 10.1128/jcm.25.11.2105-2113.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mendelman P. M., Chaffin D. O., Stull T. L., Rubens C. E., Mack K. D., Smith A. L. Characterization of non-beta-lactamase-mediated ampicillin resistance in Haemophilus influenzae. Antimicrob Agents Chemother. 1984 Aug;26(2):235–244. doi: 10.1128/aac.26.2.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Needham C. A. Haemophilus influenzae: antibiotic susceptibility. Clin Microbiol Rev. 1988 Apr;1(2):218–227. doi: 10.1128/cmr.1.2.218. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pfaller M. A., Barry A. L., Fuchs P. C., Gerlach E. H., Hardy D. J., McLaughlin J. C. Comparison of fixed concentration and fixed ratio options for testing susceptibility of gram-negative bacilli to piperacillin and piperacillin/tazobactam. Eur J Clin Microbiol Infect Dis. 1992 Aug;11(8):728–732. doi: 10.1007/BF01989979. [DOI] [PubMed] [Google Scholar]
- Powell M., McVey D., Kassim M. H., Chen H. Y., Williams J. D. Antimicrobial susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis isolated in the UK from sputa. J Antimicrob Chemother. 1991 Aug;28(2):249–259. doi: 10.1093/jac/28.2.249. [DOI] [PubMed] [Google Scholar]