SEROTYPES AND ANTIBIOTIC SUSCEPTIBILITY PATTERNS OF OPTOCHIN RESISTANT STREPTOCOCCUS PNEUMONIAE FROM ADULTS IN NIGERIA

Abstract

Intro: Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, in children and elderly. Accurate identification of S. pneumoniae is imperative for correct estimation of pneumococcal disease burden and antibiotics resistant rates. We evaluated the presence of cpsA gene in optochin resistant streptococci species, serotypes and antibiotic susceptibility patterns of cpsA positive isolates. Methods: A total of 200 sputum samples were collected from children and adults, attending Central Hospital Warri, Delta State Nigeria, between June – December, 2020. The samples were processed using standard microbiological methods. Isolates were identified by α-hemolysis, optochin susceptibility test and PCR using cspA primer. Serotyping of cpsA positive isolates was done by conventional multiplex PCR using PCV13 serotypes specific primers. Antimicrobial susceptibility pattern was performed and the results interpreted according to the recommendations of CLSI. Findings: A total of 48 (24 %) α-hemolytic and optochin resistant isolates were identified. Among the optochin resistant isolates, 2 (4.2 %) isolated from adults ≥ 61 yrs were positive for cpsA gene, so were considered as S. pneumoniae. These S. pneumoniae were serotypes not included in PCV13 (non-PCV13) and were all susceptible to vancomycin, imipenem and clindamycin. All were resistant to penicillin, amoxicillin, cefotaxime, tetracycline and trimethoprimsulphamethoxazole. 50 % were resistant to erythromycin and levofloxacin respectively. Also, they were β- lactam and multidrug resistant. Discussion: Routine microbiological methods are often inadequate to distinguish S. pneumoniae from closely related Mitis group. The introduction of PCV has drastically reduced the incidence of pneumococcal diseases caused by VTs, with a rise in NVTS. Emergence of drug resistant S. pneumoniae globally, resulted to treatment failures Conclusion: We identified two optochin resistant S. pneumoniae that were positive for cpsA gene, non-PCV13 serotypes, β- lactam and multidrug resistant. Our data suggest the need to complement traditional microbiological methods with various molecular approaches for accurate identification of S. Pneumoniae.