Genomic surveillance of methicillin-resistant Staphylococcus aureus in the Philippines, 2013-2014.

Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the leading causes of both nosocomial and community infections worldwide. In the Philippines, MRSA rates have remained above 50% since 2010, but resistance to other antibiotics, including vancomycin, is low. The MRSA burden can be partially attributed to pathogen-specific characteristics of the circulating clones, but little was known about the S. aureus clones circulating in the Philippines. We sequenced the whole genomes of 116 S. aureus isolates collected in 2013-2014 within the Antimicrobial Resistance Surveillance Program. The multilocus sequence type, spa type, SCCmec type, presence of antimicrobial resistance (AMR) determinants and virulence genes and relatedness between the isolates were all derived from the sequence data. The concordance between phenotypic and genotypic resistance was also determined. The MRSA population in the Philippines comprised a limited number of genetic clones, including several international epidemic clones, such as CC30-spa-t019-SCCmec-IV-PVL+, CC5-SCCmec-typeIV and ST239-spa-t030-SCCmec-typeIII. The CC30 genomes were related to the South-West Pacific clone but formed a distinct, diverse lineage, with evidence of global dissemination. We showed independent acquisition of resistance to sulfamethoxazole/trimethoprim in various locations and genetic clones but mostly in paediatric patients with invasive infections. The concordance between phenotypic and genotypic resistance was 99.68% overall for eight antibiotics in seven classes. We have made the first comprehensive genomic survey of S. aureus in the Philippines, which bridges the gap in genomic data from the Western Pacific Region and will constitute the genetic background for contextualizing prospective surveillance.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in the Philippines, 2012-2018.

OBJECTIVE: Data are scarce on the prevailing Streptococcus pneumoniae serotypes in the Philippines, including the relative antimicrobial resistance (AMR) of these bacteria. This study is designed to fill that gap by describing the serotype distribution and AMR of S. pneumoniae in the Philippines from 2012 to 2018. METHODS: S. pneumoniae isolates from clinical specimens were collected through the Philippine Department of Health Antimicrobial Resistance Surveillance Program from 1 January 2012 to 31 December 2018. Identification and antimicrobial susceptibility testing (AST) were performed using conventional and automated methods (Vitek2 Compact Automated Machine). AST for penicillin, erythromycin, co-trimoxazole, ceftriaxone and levofloxacin was done following the Clinical and Laboratory Standard Institute recommendations. Serotyping was done through slide agglutination following the Denka Seiken slide agglutination method. RESULTS: From a total of 307 isolates of S. pneumoniae, 32 serotypes were identified; the most frequently occurring were serotypes 1, 3, 5, 4, 18, 19A, 6B, 15 and 14. Many (n = 113, 36.53%) of the isolates were from those aged £5 years. Pneumococcal conjugate vaccine (PCV) coverage was as follows: PCV7 (32.69%), PCV10 (54.16%) and PCV13 (69.23%). The overall AMR of invasive S. pneumoniae isolates was low. Penicillin-resistant serotypes were 14, 19, 24, 4, 5, 1, 15, 6 and 32. DISCUSSION: With the inclusion of PCV13 in the National Immunization Program, continued monitoring of the prevailing serotypes of S. pneumoniae isolates in the Philippines is needed to guide disease and AMR control measures.