Ampicillin-Resistant Non-β-Lactamase-Producing Haemophilus influenzae in Spain: Recent Emergence of Clonal Isolates with Increased Resistance to Cefotaxime and Cefixime

Autor: Francisco J. de Abajo, Emilia Cercenado, María Pérez-Vázquez, Edurne Lázaro, José Campos, Jesús Oteo, César García-Rey, Federico Román, Silvia García-Cobos
Rok vydání: 2007
Předmět:
Cefotaxime
Cephalosporin
medicine.disease_cause
Polymerase Chain Reaction
Haemophilus influenzae
Ampicillin
Pharmacology (medical)
Bacterial/analysis
Antibacterial agent
Gel
Molecular Epidemiology
Molecular Epidemiology/methods
Cephalosporin Resistance
Bacterial
Cefixime/pharmacology
Anti-Bacterial Agents
Electrophoresis
Gel
Pulsed-Field
Infectious Diseases
Spain/epidemiology
beta-Lactamases/metabolism
Efflux
Sequence Analysis
Lysine/metabolism
medicine.drug
Electrophoresis
DNA
Bacterial
medicine.drug_class
Microbial Sensitivity Tests
Biology
beta-Lactamases
Anti-Bacterial Agents/pharmacology
Microbiology
Pulsed-Field
Amp resistance
Mechanisms of Resistance
Cefixime
medicine
Humans
Histidine
DNA
Bacterial/analysis
Pharmacology
Haemophilus influenzae/drug effects
Lysine
Histidine/metabolism
Genetic Variation
DNA
Sequence Analysis
DNA
Genes
Amino Acid Substitution
Spain
Genes
Bacterial
Cefotaxime/pharmacology
Ampicillin Resistance
Zdroj: Antimicrobial Agents and Chemotherapy, 51(7), 2564-2573. AMER SOC MICROBIOLOGY
ISSN: 1098-6596
0066-4804
Popis: The sequence of the ftsI gene encoding the transpeptidase domain of penicillin-binding protein 3 (PBP 3) was determined for 354 nonconsecutive Haemophilus influenzae isolates from Spain; 17.8% of them were ampicillin susceptible, 56% were β-lactamase nonproducing ampicillin resistant (BLNAR), 15.8% were β-lactamase producers and ampicillin resistant, and 10.4% displayed both resistance mechanisms. The ftsI gene sequences had 28 different mutation patterns and amino acid substitutions at 23 positions. Some 93.2% of the BLNAR strains had amino acid substitutions at the Lys-Thr-Gly (KTG) motif, the two most common being Asn526 to Lys (83.9%) and Arg517 to His (9.3%). Amino acid substitutions at positions 377, 385, and 389, which conferred cefotaxime and cefixime MICs 10 to 60 times higher than those of susceptible strains, were found for the first time in Europe. In 72 isolates for which the repressor acrR gene of the AcrAB efflux pump was sequenced, numerous amino acid substitutions were found. Eight isolates with ampicillin MICs of 0.25 to 2 μg/ml showed changes that predicted the early termination of the acrR reading frame. Pulsed-field gel electrophoresis analysis demonstrated that most BLNAR strains were genetically diverse, although clonal dissemination was detected in a group of isolates presenting with increased resistance to cefotaxime and cefixime. Background antibiotic use at the community level revealed a marked trend toward increased amoxicillin-clavulanic acid consumption. BLNAR H. influenzae strains have arisen by vertical and horizontal spread and have evolved to adapt rapidly to the increased selective pressures posed by the use of oral penicillins and cephalosporins.
Databáze: OpenAIRE
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