Ampicillin Resistance in Haemophilus influenzae Isolated from Acute Respiratory Infections in Pediatrics

Haemophilus influenzae is a bacterium that can cause severe infections, occurring mostly in infants and children younger than five years of age. Antibiotic treatment may cause the emergence of resistant H. influenzae strains, particularly ampicillin-resistant strains. Antimicrobial resistance is a public health threat worldwide, particularly in the developing world. H. influenzae strains have been isolated from broncho-alveolar lavages (BALs), nasopharyngeal swabs, and otitis media from children in two paediatric centers at Dakar, Senegal. Antibiotic susceptibility testing was carried out using strips E Test ®t method that provides the ability to precisely determine the minimum inhibitory concentration (MIC). A total of 16 H. influenzae strains have been isolated and identified, including 16.7% of ampicillin-resistant patterns (all β-lactamase-negative), 9.4% of the isolates were resistant to cefaclor (MIC90 = 16 µg/ml) while 100% were susceptible to cefixime to (MIC90 = 0.38 µg/ml). Interestingly, fluoroquinolones were fully active with very low MIC90. Macrolide were still active against H. influenzae isoles although with higher MIC azitrhomycin MIC90= 3µg/ml, clarithromycin MIC90= 12µg/ml. Ampicillin-resistance has become increasingly reported in H. influenzae, suggesting a continuous laboratory based surveillance for antimicrobial resistance pattern for a better management of acute respiratory infections, particularly in low incomes settings.