Publikationsdatenbank

Differences in susceptibility testing for sulfamethoxazole-trimethoprim among clinical Staphylococcus aureus isolates (2019)

Art

Poster

Autoren

Scholtzek, A. D. (WE 7)

Klein, S.-K. (WE 17)

Stöckle, S. D. (WE 17)

Eichhorn, I. (WE 7)

Walther, B.

Feßler, A. T. (WE 7)

Hanke, D. (WE 7)

Gehlen, H. (WE 17)

Lübke-Becker, A. (WE 7)

Schwarz, S. (WE 7)

Kongress

Zoonoses 2019 - International Symposium on Zoonoses Research

Berlin, 16. – 18.10.2019

Quelle

Zoonoses 2019 - International Symposium on Zoonoses Research : Book of Abstracts — International Symposium on Zoonoses Research (Hrsg.)

Berlin, 2019 — S. 164

Sprache

Englisch

Verweise

URL (Volltext): https://evis.events/event/79/attachments/23/154/Book_of_Abstracts_Zoonoses2019.pdf

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Background and objectives:
Antimicrobial susceptibility testing (AST) with an automated testing system (AS1) and broth microdilution (BMD1) showed differing results regarding sulfamethoxazole-trimethoprim (SXT) for Staphylococcus aureus. These findings were further investigated.

Material and methods:
S. aureus isolates (n=19) from horses revealed differing SXT susceptibility results. Therefore, a second AS (AS2) and further CLSI approved methods were tested: two BMD tests, including a commercial plate (BMD2), an inhouse set-up (BMD3) for sulfisoxazole (SUL) and trimethoprim (TMP) separately, and disk diffusion (DD) for SXT, SUL and TMP. Respective resistance geneswere deduced fromwhole genome sequences.

Results:
AS1 identified all isolates as SXT-resistant, whereas the BMD1 classified only threeisolates as resistant and 16 as susceptible. AS2 classified 17 as resistant and two as susceptible and BMD2 classified all but one as resistant. DD identified three as SXT-resistant, eleven asSXT-intermediate andfive as SXT-susceptible. For SUL, BMD3 classified 16 as susceptible and three as resistant, whereas in DD all were susceptible. In BMD3 and DD,all isolates were TMP-resistant. All isolates harbored a TMP resistance gene (dfrG [n=3] or dfrS1 [n=16]).

Conclusion:
SXT is used in human and veterinary medicine.Therefore, a correct classification of the AST results of bacterial pathogens is important, keeping in mind that different methods can reveal different results.