Serotype Distribution and Antimicrobial Resistance of Streptococcus pneumoniae in the Philippines, 2004-2011

Abstract

Objective. Scarcity of data on the serotype composition and antibiotic resistance of invasive pneumococci from developing countries has been noted. We describe in this study the serogroup distribution and antimicrobial resistance patterns of Streptococcus pneumoniae in the Philippines from 2004-2011. Methodology. S. pneumoniae isolated from patients with invasive pneumococcal disease were referred to the Antimicrobial Resistance Surveillance Reference Laboratory from 2004 to 2011. Typing of isolates was done through slide agglutination and antimicrobial susceptibility was determined following CLSI methods. Results. The penicillin-resistant meningitis isolates were of serotypes 1, 5 and 14 which are covered by PCV10 and 13. The erythromycin resistant isolates were serotype 9 while cotrimoxazole resistant isolates were serotypes 1, 5, 6, 12 and 14. Forty-one percent of the cotrimoxazole resistant isolates are covered by PCV7, and 88% are covered by both PCV10 and PCV13. Levofloxacin resistant isolates were of serotypes 5 and 23 with PCV7 coverage of 50% and PCV10 and PCV13 coverages of 100%. Conclusion. S. pneumoniae serotypes causing IPD in the country is largely similar to the dominant IPD serotypes worldwide. The serotype distribution in the Philippines remained stable from 2004 to 2011 and antimicrobial resistance among the isolates remained low. The serotypes of antibiotic resistant S. pneumoniae in this study were not similar with known serotype resistance profiles in other Asian countries. With the inclusion of PCV in the national free national immunization program of the country beginning 2013, continued surveillance of prevailing pneumococcal serotypes should be done to monitor any shift in the prevalence of PCV associated serotypes to guide disease control measures including control of emergence of resistant pneumococcal isolates.