Identification of β-Haemolytic Streptococci among Pharyngitis Cases at Bir Hospital, Kathmandu

Abstract

Respiratory tract infection is one of the major reasons of patients seeking medical care. Among infections pharangitis is most common in the upper respiratory tract, which is seen most frequently in children and adolescents and less frequently among adults. The objective of this study was to analyze the underlying bacterial pathogens in pharyngitis cases and antibiotic susceptibility of various isolates. During February to August, 2010, a total of 134 patients visiting E.N.T. OPD of Bir Hospital complaining sore throat were studied. The throat swabs of the patients were cultured in 5.0% sheep blood agar plates and incubated at 37°C for 24-48 hrs. Clear transparent β-haemolytic colonies of the germs were selected and identified. Group A streptococcus was identified by β-haemolytic colonies with bacitracin and penicillin sensitivity, gram staining, catalase negativity and growth on crystal violet blood agar. In this study, 23 (17.2%) patients were positive for β-haemolytic streptococci. Among them, 12 (9%) were identified as Group A streptococcus. The culture positive for BHS was highest (56.5%) among the age group of 21-40 years. Pathogens other than β-haemolytic streptococci were isolated from 9 patients, of which 4 cases showed mixed bacterial growth. Other bacterial isolates reported in the study were Staphylococcus aureus 6 (4.5%), Klebsiella pneumoniae 5 (3.7%), Pseudomonas aeruginosa 2 (1.5%), Citrobacter freundii 1 (0.7%), and yeast cells 1 (0.7%). It was found that infections caused by β-haemolytic streptococci was significantly higher p=0.0084 i.e. (p<0.05) than infections caused by other bacteria. This study demonstrated that young adults of age group 21-40 were affected by streptococcal pharyngitis. The isolates of GAS were 100% sensitive to amoxycillin, cephalexin, cefotaxime, ciprofloxacin and azithromycin followed by cotrimoxazole (91.7%) and erythromycin (91.7%).

DOI: http://dx.doi.org/10.3126/njst.v14i2.10427

Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 137-142