Antimicrobial susceptibility and serotypes of Neisseria meningitidis and Streptococcus pneumoniae in Sri Lanka: Experience from the National Reference Laboratory
Lilani Karunanayake1, Veeraraghavan Balaji2, K. D.N. Gunawardana1, Rosemol Varghese2, Vayishnavi Ariram1, Malka Dassanayake3, Vaithehi Rajeevan Francis4, Lakmini Yapa5, Chamika Herath6, Nambage Shirani Chandrasiri7, Priyanka Wimalagunawardhana8, K Dhananja Namalie9, CT Hapuarachchi10
1 Department of Bacteriology, Medical Research Institute, Colombo, Sri Lanka
2 Department of Microbiology, Christian Medical College, Vellore, India
3 Lady Ridgeway Children's Hospital, Colombo, Sri Lanka
4 Department of Pathophysiology, Faculty of Healthcare Sciences, Eastern University, Sri Lanka
5 Teaching Hospital, Anuradhapura, Sri Lanka
6 District General Hospital, Moneragala, Sri Lanka
7 Colombo South Teaching Hospital, Kalubowila, Sri Lanka
8 District General Hospital, Polonnaruwa, Sri Lanka
9 North Colombo Teaching Hospital, Ragama, Sri Lanka
10 District General Hospital, Mannar, Sri Lanka
Department of Bacteriology, Medical Research Institute, Colombo
Source of Support: None, Conflict of Interest: None
Objective: To determine the antimicrobial susceptibility and serotypes of Neisseria (N.) meningitidis and Streptococcus (S.) pneumoniae in Sri Lankan patients.
Methods: We retrospectively analyzed 11 blood culture specimens from suspected patients with invasive meningococcal disease and 26 S. pneumoniae clinical isolates. We tested 6 antimicrobials against N. meningitidis and 12 antimicrobials against S. pneumoniae. Meningococcal serogroup was determined by realtime PCR and Quellung serotyping was used for pneumococcal analysis.
Results: N. meningitidis serogroup B was the most common in this study. Intermediate-susceptibility to penicillin was seen in 75.0% (6/8) of strains. Susceptibility to ciprofloxacin, levofloxacin and cotrimoxazole was 62.5% (5/8), 62.5% (5/8) and 87.5% (7/8), respectively. Excellent susceptibility was seen in cefotaxime and meropenem. In S. pneumoniae, the most common serotype was 19F in both invasive and non-invasive pneumococcal diseases. The majority of strains showed multidrug resistance. Penicillin non-susceptibility in non-meningeal strains were 13.6% and all meningeal strains were penicillin resistant. Erythromycin was highly resistant in both groups. Amoxicillin showed excellent susceptibility in non-invasive pneumococcal diseases strains. Linezolid, levofloxacin and vancomycin showed 100.0% susceptibility in all pneumococcal isolates.
Conclusions: Implementation of vaccines should be considered, especially for children and high-risk populations. This may contribute to reducing pneumococcal and meningococcal invasive disease burden and help prevent emergence of antimicrobial resistant strains.