Antibiotic Susceptibility Pattern Of Optochin Resistant Viridan Streptococci In Sputum Samples Of Patients In Central Hospital, Warri, Delta State.

Abstract

The viridans group streptococci (VGS), are a heterogeneous group of bacteria belonging to the genus Streptococcus. They act as a reservoir for antibiotic resistance genes, thus transferring different resistance traits to more pathogenic organisms like S. pneumonae and S. pyogenes.  The aim of this study was to evaluate the antibiotic resistance in optochin-resistant (VGS) from the sputum samples of patients from all age groups at Central Hospital, Warri, Delta State, Nigeria. A total of 200 sputum samples were collected from patients with clinical symptoms of tuberculosis, pneumonia and other respiratory tract infections. The VGS were isolated and identified using standard methods. The antibiotic susceptibility testing of the isolated VGS was performed according to Clinical and Laboratory Standards Institute’s recommendations. A total of 48 (24 %) VGS were isolated. All of the isolates (100 %) were susceptible to imipenem and resistant to cefotaxime.   95.83 % of the isolates were susceptible to vancomycin while 89.58 %, 83.33 %, 79.16 %, 77.08 %, 68.75%  and 52.08 % of the isolates were resistant to penicillin, trimethoprim-sulphamethoxazole, tetracycline, amoxicillin, clindamycin and levofloxacin respectively. The isolated VGS were 22(45.83 %) resistant and 11(22.90 %) intermediately resistant to erythromycin. Multidrug resistance was seen in all the VGS isolated, with co-resistance to ?-lactam,  macrolides, tetracycline and trimethoprim-sulphamethoxazole. This study showed that imipenem, vancomycin and clindamycin remain the drugs of choice for the treatment of infections caused by VGS. Multidrug resistance, especially to ?-lactam antibiotics was observed in the VGS isolated. There is need for continuous evaluation of antimicrobial susceptibility pattern among VGS for effective antibiotic therapy and to track resistance overtime.