Molecular Epidemiology of Nontypeable Haemophilus influenzae in Community-Acquired Pneumonia

What is it about?

This study aimed to determine the antimicrobial susceptibility, b-lactam resistance, and genetic characterization of Nontypeable Haemophilus influenzae (NTHi) isolates causing community-acquired pneumonia (CAP) in adults. Ninety-five NTHi isolates were analyzed, and 33.7% showed reduced susceptibility to ampicillin. The ftsI gene was PCR amplified and sequenced, revealing amino acid substitutions in PBP3. Most patients with non-susceptible NTHi isolates were successfully treated with amoxicillin/clavulanic acid, ceftriaxone, or levofloxacin. The study demonstrated a high genetic diversity among NTHi strains and emphasized the importance of understanding the underlying mechanisms of antimicrobial resistance to optimize treatment strategies.

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Why is it important?

This study is important for several reasons: It provides valuable insights into the genetic characterization and antimicrobial resistance of Nontypeable Haemophilus influenzae (NTHi), a common cause of respiratory infections in adults. It highlights the high genetic diversity among NTHi isolates, which contributes to our understanding of the potential for the emergence of resistant strains. The study demonstrates the impact of antibiotic use and comorbidities on patient outcomes, emphasizing the need for appropriate treatment and infection control measures. Key Takeaways: 1. NTHi causing community-acquired pneumonia (CAP) in adults shows high genetic diversity and is associated with a high rate of reduced susceptibility to ampicillin due to alterations in PBP3. 2. Antimicrobial resistance to ampicillin varies among European countries, with the rate found in this study being higher than some recent reports. 3. Treatment with amoxicillin/clavulanic acid, ceftriaxone, or levofloxacin is effective for patients infected with NTHi strains with mutations in the ftsI gene, which are resistant to ampicillin. 4. The consumption of aminopenicillins in Catalonia increased from 1992 to 2007, which may contribute to the frequency of gBLNAR observed in this study.