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. 1976 Jan;9(1):199–200. doi: 10.1128/aac.9.1.199

Spurious Ampicillin Resistance by Testing Haemophilus influenzae with Agar Containing Supplement C

John A Washington II 1, Robert J Snyder 1, Peggy C Kohner 1
PMCID: PMC429499  PMID: 1083201

Abstract

Ampicillin resistance (minimal inhibitory concentration ≥10 μg/ml) in the absence of beta-lactamase activity by Haemophilus influenzae was noted in tests performed with Mueller-Hinton agar containing one lot of supplement C. All strains, except five with known resistance due to beta-lactamase activity, were inhibited by 0.6 μg or less of ampicillin per ml of chocolatized blood agar.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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