Prevalence and Antimicrobial Susceptibility of Streptococcus pneumoniae Isolated from Hospital in Thailand between 2016 and 2020
Piriyaporn Chongtrakool¹, Yukol Aphiyakul², Patcharee Choochur², Chalermsri Pummangura³, Maytinee Srifuengfung⁴, Apichote So-Ngern³, Ruxjinda Wattanalai³, Somporn Srifuengfung³
Affiliation : ¹ Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ² Microbiology Laboratory, Taksin Hospital, Bangkok, Thailand ³ Faculty of Pharmacy, Siam University, Petchkasem Road, Bangkok, Thailand ⁴ Department of Psychiatry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective: To determine prevalence and antimicrobial susceptibility of Streptococcus pneumoniae at Taksin Hospital.
Materials and Methods: A retrospective descriptive study was conducted between January 2016 and December 2020. The bacterial susceptibility of isolates to clindamycin, erythromycin, trimethoprim-sulfamethoxazole, levofloxacin, and vancomycin were evaluated by the disk diffusion method. Bacterial susceptibility to penicillin and cefotaxime were evaluated for minimal inhibitory concentration (MIC) by a strip test (E-test).
Results: One hundred and nineteen patients were included, 65.55% male, and the age ranged from three months to 98 years. The median age of patients was 60 years with an interquartile range of 43 to 78 years. Unduplicated pneumococci from different patients were isolated from sputum (70.59%), blood (18.49%), and pus from ears and sinuses (5.04%). S. pneumoniae was demonstrated to be 100% susceptible to vancomycin and levofloxacin but less susceptible to clindamycin, erythromycin, and trimethoprim-sulfamethoxazole by disk diffusion method. Pneumococci exhibited total multiple drug resistance (MDR) at 31.94%. The predominant MDR pattern was clindamycin + erythromycin + trimethoprimsulfamethoxazole (31.10%). The MIC range, MIC₅₀, and MIC₉₀ of penicillin was 0.008 to 3.0, 0.25, and 2.0, and for cefotaxime, it was 0.008 to 1.0, 0.25, and 1.0 μg/mL, respectively. From an extra study to determine serotypes, S. pneumoniae isolated from blood or CSF (n=25) were randomly picked between 2007 and 2021 from Thai IBIS and Taksin Hospital. The three most common serotypes were 19F (20%), 6B (16%), and 6A (12%).
Conclusion: These results suggest the importance of monitoring the prevalence of pneumococci. The antibiogram of susceptibility helps provide guidelines for clinician to consider empirical treatment. An antibiogram is an overall profile of antimicrobial susceptibility testing results of pneumococci to a battery of antimicrobial drugs. Antibiograms are often used by clinicians to assess local susceptibility rates, as an aid in selecting empiric antibiotic therapy, and in monitoring resistance trends over time within an institution. Antibiograms can also be used to compare susceptibility rates across institutions and track resistance trends.
Received 17 October 2021 | Revised 17 January 2022 | Accepted 17 January 2022
DOI: 10.35755/jmedassocthai.2022.02.13266
Keywords : Streptococcus pneumoniae; Pneumococci; Drug resistance
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