Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Antimicrobial susceptibility of Streptococcus pneumoniae isolated from sputum of patients presenting at patan hospital (#32)

Saugat Bhandari 1 , Piyush Rajbhandari 1 , Meeru Gurung 1 , Rusy Shrestha 1 , Ruby Basi 1 , Kanchan Bogati 1 , Aayush Rizal 1 , Sanjeev Bijukchhe 1 2 , Bhishma Pokhrel 1 , Krishna Govinda Prajapati 1 , Shristy Rajkarnikar 1 , Madhav Gautam 1 , Buddhi Paudyal 1 , Anil Ojha 1 , Shrijana Shrestha 1
  1. Patan Academy of Health Sciences, Kathmandu, Nepal
  2. Oxford Vaccine Group, Department of Pediatrics, University of Oxford, Oxford, United Kingdom

Background:

Streptococcus pneumoniae (pneumococcus) is one of the causes of invasive bacterial disease in all age group of patients, although sputum culture of S. pneumoniae denotes presumptive pneumococcal diseases. This study analyzed the antibiotic susceptibility of S. pneumoniae isolated from sputum cultures of patients presenting to Patan between January 2017 and December 2024.

Methods:

The antimicrobial susceptibility of pneumococcal isolates from sputum cultures of patients at Patan Hospital was evaluated although not all antibiotics were tested throughout the years. These tests were conducted by applying the Kirby Bauer disc diffusion method, in adherence to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

Results:

Streptococcus pneumoniae was isolated from sputum samples of 194 patients, comprising 106 males (54.64%) and 88 females (45.36%). All tested isolates demonstrated 100% sensitivity to both vancomycin (174/174) and linezolid (172/172). Likewise, sensitivity to Penicillin was observed in 70% (16/23), while 67% (112/167) were susceptible to oxacillin. Additionally, 92% (177/193) were sensitive to chloramphenicol, and 57% (102/179) to clindamycin. However the macrolides group of antibiotics showed 39% (73/188) sensitivity to azithromycin and 38% (72/188) to erythromycin. Also, fluoroquinolones likes ofloxacin showed 67% (124/185) of sensitivity.

Conclusions:

S. pneumoniae exhibits higher susceptibility to oxazolidinones (Linezolid) and glycopeptides (vancomycin) group of antibiotics. Penicillin and oxacillin group of antibiotics although being the first line of treatment showed less effectiveness. The low sensitivity to macrolides highlights the importance of antimicrobial stewardship since overuse of these antibiotics may have lead to increased resistance.