caa a22 4500 606156690 CHVBK 20210128100610.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s10096-015-2435-5 doi (NATIONALLICENCE)springer-10.1007/s10096-015-2435-5 Ampicillin-resistant Haemophilus influenzae isolates in Geneva: serotype, antimicrobial susceptibility, and β-lactam resistance mechanisms [Elektronische Daten] [A. Cherkaoui, S. Diene, S. Emonet, G. Renzi, P. Francois, J. Schrenzel] The purpose of this study was to analyze the molecular mechanisms of ampicillin-resistant Haemophilus influenzae isolated in Geneva, Switzerland. We investigated the association between specific patterns of amino acid substitutions in penicillin-binding protein 3 (with or without β-lactamase production) and β-lactam susceptibility. Another main focus for this study was to compare the accuracy of disk diffusion and Etest methods to detect resistance to ampicillin and amoxicillin/clavulanic acid. The antibiotic susceptibility to β-lactam antibiotics of 124 H. influenzae isolates was determined by disk diffusion and Etest methods, and interpreted by European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) breakpoints. Alterations in PBP3 were investigated by sequencing the ftsI gene. Of the 124 clinical isolates analyzed, ampicillin resistance was found in 36% (45 out of 124). The rate of resistance to amoxicillin/clavulanic acid was 9% and 0.8%, using EUCAST and CLSI breakpoints respectively. For the 78 β-lactamase negative ampicillin-susceptible (BLNAS) isolates for which the Etest method indicated a high degree of susceptibility (MIC ≤ 1mg/L), the disk diffusion method revealed resistance to ampicillin and amoxicillin/clavulanic acid in 33 cases (42%). Most common amino acid substitutions were Asn526Lys and Val547Ile, followed by Asp569Ser, Ala502Val, Asp350Asn, Met377Ile, Ile449Val, and Arg517His. The patterns observed were classified into six groups (IIa, IIb, IIc, IId, III-like, and miscellaneous). Continued characterization of both invasive and respiratory H. influenzae isolates is necessary in order to observe changes in the microbiology and epidemiology of this pathogen that could lead to clinical failure when treated by empirical antibiotic therapy. Springer-Verlag Berlin Heidelberg, 2015 Cherkaoui A. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut Diene S. Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut Emonet S. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut Renzi G. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut Francois P. Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut Schrenzel J. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/10(2015-10-01), 1937-1945 0934-9723 34:10<1937 2015 34 10096 https://doi.org/10.1007/s10096-015-2435-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10096-015-2435-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cherkaoui A. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 700 1- Diene S. Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 700 1- Emonet S. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 700 1- Renzi G. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 700 1- Francois P. Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 700 1- Schrenzel J. Bacteriology Laboratory, Division of Laboratory Medicine, Department of Genetics and Laboratory Medicine, Geneva University Hospitals, 4 rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland aut NATIONALLICENCE 773 0- European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/10(2015-10-01), 1937-1945 0934-9723 34:10<1937 2015 34 10096