Phenotypic detection of clinical isolates of Haemophilus influenzae with altered penicillin-binding protein 3
| Autor: | I. C. Pérez del Molino, M. C. Sanjuán, Luis Martínez-Martínez, C. García de la Fuente, A. Aguirre-Quiñonero, Jesús Agüero |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Microbiology (medical) Haemophilus Infections Penicillin binding proteins Sequence analysis medicine.drug_class 030106 microbiology Antibiotics Microbial Sensitivity Tests Biology medicine.disease_cause Benzylpenicillin Microbiology Haemophilus influenzae 03 medical and health sciences Aminopenicillin Ampicillin Drug Resistance Bacterial medicine Humans Penicillin-Binding Proteins Amoxicillin Genetic Variation General Medicine biochemical phenomena metabolism and nutrition Anti-Bacterial Agents Phenotype Infectious Diseases Amino Acid Substitution Mutation medicine.drug |
| Zdroj: | European Journal of Clinical Microbiology & Infectious Diseases. 37:1475-1480 |
| ISSN: | 1435-4373 0934-9723 |
| DOI: | 10.1007/s10096-018-3273-z |
| Popis: | The aims of this study were to determine the correlation of mutations in the ftsI gene (coding for PBP3) of Haemophilus influenzae with aminopenicillin resistance and to evaluate the 2017 European Committee for Antibiotic Susceptibility Testing (EUCAST) guidelines for clinical categorization of ampicillin, amoxicillin, and amoxicillin-clavulanate for strains with mutated PBP3 conferring resistance (rPBP3). A panel of 91 H. influenzae isolates was genetically characterized by sequencing of the fstI gene. For all the studied isolates, a screening with benzylpenicillin 1U (BP1) was carried out and minimum inhibitory concentrations (MICs) of ampicillin, amoxicillin, and amoxicillin-clavulanate were tested and interpreted according to EUCAST recommendations. ftsI sequence analysis revealed a total of 14 different amino acid substitutions in PBP3. The substitution patterns most commonly observed were [D350N, M377I, A502V, N526K] among the bla-positive rPBP3 strains (37.5%) and [D350N, A502T, N526K] among the bla-negative rPBP3 strains (24.5%). Screening with BP1 was able to correctly categorize 100% of the bla-negative sPBP3 strains, 100% of the bla-positive strains, and 92% of the bla-negative rPBP3 ones. Only 29% of the bla-negative rPBP3 strains evaluated displayed ampicillin MICs above the current EUCAST resistant breakpoint defined at 1 μg/ml. The PBP3 substitution patterns of the strains evaluated are similar to the ones observed in previous Spanish and European studies. Although the screening with BP1 proved to be adequate in the detection of bla-negative rPBP3 strains, these cannot be reliably identified by current 2018 EUCAST breakpoints for ampicillin. |
| Databáze: | OpenAIRE |
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