Related Experiment Videos
Streptococcus pneumoniae from ophthalmic infections: serotype distribution and penicillin susceptibility
M S Mathews1, A Sivanandan, A Manoharan
1Department of Clinical Microbiology, Christian Medical College and Hospital, Vellore, India. mmathews@micro.cmc.ernet.in
Abstract:
Streptococcus pneumoniae is one of the pathogens causing infection of the conjunctiva and the uveal tract. The present study began with the observation of two ophthalmic S. pneumoniae isolates showing intermediate resistance to penicillin. Among the 25 isolates of S. pneumoniae from 617 ophthalmic specimens, during the period of 14 months, four were found to exhibit an intermediate resistance to penicillin. Minimum Inhibitory Concentration values ranging from 0.125 microg/mL to 0.25 microg/mL was observed. No multidrug resistant strains were isolated. Serogrouping/typing of the S. pneumoniae revealed the following serogroups/types; 6A (n = 3), 6B (n = 2), 22 (n = 3), 14 (n = 3), 23A (n = 2), and 1 each of 23B, 19A, 7B, 32, 9, 42, 21, 39, 10, 3, and 34. One strain showed cross reaction in pool 29, 35, and 47. These findings represent the first such observation of ophthalmic isolates from India.
Insights
This study identified penicillin-intermediate resistance in Streptococcus pneumoniae ophthalmic isolates from India. No multidrug-resistant strains were found, indicating a need for ongoing surveillance of ocular pathogens.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Streptococcus pneumoniae is a common cause of ocular infections, including conjunctivitis and uveitis.
- Antibiotic resistance in S. pneumoniae poses a significant threat to effective treatment of ophthalmic infections.
Purpose of the Study:
- To investigate the prevalence of penicillin resistance in S. pneumoniae isolated from ophthalmic specimens in India.
- To characterize the antibiotic resistance profiles and serotypes of these isolates.
Main Methods:
- Analysis of 617 ophthalmic specimens collected over 14 months.
- Isolation and identification of S. pneumoniae.
- Determination of penicillin Minimum Inhibitory Concentration (MIC) values.
- Serogrouping/typing of identified S. pneumoniae isolates.
Main Results:
- Four out of 25 S. pneumoniae isolates exhibited intermediate resistance to penicillin, with MICs ranging from 0.125 to 0.25 microg/mL.
- No multidrug-resistant strains were detected.
- Common serogroups identified included 6A, 6B, 14, and 22.
Conclusions:
- This study reports the first observation of penicillin-intermediate resistant S. pneumoniae ophthalmic isolates in India.
- The findings highlight the emergence of antibiotic resistance in ocular S. pneumoniae and underscore the importance of antimicrobial susceptibility monitoring.