Possible misinterpretation of penicillin susceptibility in Staphylococcus aureus blood isolate due to in vitro loss of the blaZ gene.

Autor: Eriksen HB; Department of Clinical Microbiology, Copenhagen University Hospital, Herlev and Gentofte, Borgmester Ib Juuls Vej 52, 5., 2730, Copenhagen, Herlev, Denmark. helle.brander.eriksen.01@regionh.dk., Petersen A; National Reference Laboratory for Antimicrobial Resistance, Statens Serum Institut, Copenhagen, Denmark., Pedersen M; Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark., Overballe-Petersen S; National Reference Laboratory for Antimicrobial Resistance, Statens Serum Institut, Copenhagen, Denmark., Larsen AR; National Reference Laboratory for Antimicrobial Resistance, Statens Serum Institut, Copenhagen, Denmark., Holzknecht BJ; Department of Clinical Microbiology, Copenhagen University Hospital, Herlev and Gentofte, Borgmester Ib Juuls Vej 52, 5., 2730, Copenhagen, Herlev, Denmark.
Jazyk: angličtina
Zdroj: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology [Eur J Clin Microbiol Infect Dis] 2022 Jan; Vol. 41 (1), pp. 163-167. Date of Electronic Publication: 2021 Sep 16.
DOI: 10.1007/s10096-021-04344-w
Abstrakt: We describe a case of recurrent catheter-related blood stream infections (BSI) with Staphylococcus aureus, in which the first isolate tested susceptible to penicillin, while subsequent isolates were resistant. Phenotypic susceptibility correlated with the absence/presence of the blaZ gene. The in vitro stability of penicillin resistance was investigated by subculturing single colonies. In two out of five colonies, phenotypical resistance was lost after a single subculture, which correlated with loss of the blaZ gene. This in vitro phenomenon probably resulted in a very major error in the microbiology report of the first BSI, where penicillin had been recommended as treatment.
(© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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