Background: The spread of antimicrobial resistance threatens effective control and treatment of pneumococcal disease worldwide. In Kenya, an estimated one in every five children dies from pneumococcal disease every year. Of these, ≥50% are attributable to antibiotic resistance. Consequently, the WHO has recommended that continuous regional surveillance be done to detect early resistance to available antibiotics and make necessary changes. We therefore investigated antimicrobial susceptibility patterns of Streptococcus pneumoniae among PCV-10 vaccinated and unvaccinated children ≤5 years old at Gertrude's Children’s Hospital. Methods: A 0.5 McFarland standard of freshly subcultured organisms were inoculated on Mueller–Hinton plates with 5% sheep blood agar. A standard disk dispenser was used to dispense various antibiotic disks on the Mueller–Hinton agar plate. Incubation was done overnight (20-24 hours) at 37oC in 5% CO2 and clearance zones read using a Vanier caliber. Antimicrobials tested included vancomycin (30µg, ≥17mm); erythromycin (15µg, ≥21mm); clindamycin (2µg, ≥19mm); oxacillin (1µg, ≥19mm) and ceftriaxone (1µg, ≥30mm). Results: Thirty nine (92.86%) Streptococcus pneumoniae isolates were susceptible to erythromycin; 39 (92.86%) were susceptible to vancomycin; eight (19.86%) Streptococcus pneumoniae isolates were susceptible to oxacillin, while 34 (80.95%) were non-susceptible; 40 (95.24%) isolates were susceptible to clindamycin; and 24 (57.86%) isolates were susceptible to ceftriaxone, while 18 (42.86%) were non-susceptible. Children who attended daycare centers exhibited a four-fold significant risk of being resistant to ceftriaxone. All antibiotics studied were effective against Streptococcus pneumoniae except oxacillin and ceftriaxone, which exhibited high levels of non-susceptibility. Attendance of daycare centers, consumption of antibiotics two weeks prior to collection of sample and subject age were shown to be associated with an increased risk of Streptococcus pneumoniae being resistant to penicillins and ceftriaxone. Conclusions: The law guiding use of antibiotics in Kenya should be meritoriously enforced to curb abuse of the available antibiotics.
Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae causing noninvasive diseases in a Children's Hospital, Shanghai
