Antibiotic Susceptibility Patterns in Adenotonsillar Bacterial Isolates in a Tertiary Hospital in Sub-Saharan Africa

Background: The adenoids and tonsils are parts of Waldeyer's ring and are essentially the first line of immunological defense of the upper respiratory tract. These lymphoid tissues can frequently become infected, resulting in hypertrophy and recurrent tonsillitis. Bacterial infections are the main causative agents in chronic adenotonsillitis. Frequently implicated organisms seen ln the adenoids and tonsils include Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and sometimes anaerobic bacteria. The rise of antimicrobial resistance has greatly diminished the effectiveness of widely used antibiotics.

Objective: The aim of this study is to examine the microbiological characteristics and antibiotic susceptibility patterns of bacterial isolates obtained from adenotonsillar tissues of children undergoing tonsillectomy in a tertiary hospital in Nigeria.

Methods: A hospital based cross-sectional study among patients undergoing adenotonsillectomy. Swab was taken from adenoid and tonsillar tissues and sent for sent for microbiology culture and sensitivity. Data entry and analysis was done using the Statistical Product and Service Solutions (SPSS) version 20. Tables and charts were used as appropriate to represent data. Numerical variables were summarized as means and standard deviation for age while categorical variables were expressed as frequencies and percentages.

Results: A total of 50 patients aged 3 years to 7 years were included in the study. A median age of 4.0 years and mean age of 4.4± 1.5 years was gotten. Most (62% of the patients were under five male/female ratio of 1.3: 1. Most of the adenoid (40%) and tonsillar (32%) tissues did not yield growth. Viridan group of Streptococcus seen 20% of tonsils was the commonest organism isolated from the tonsils. Staphylococcus aureus as seen in 22% of cases was commonest bacterial isolate from the adenoid. Regarding antibiotic susceptibility, aerobic bacteria was resistant to most of the antibiotics. The sensitivity pattern of Staphylococcus aureus was as follows; erythromycin (59.5%), cefuroxime (54.1%), ciprofloxacin(51.2%) and amoxicillin/clavulanic acid (51.2%).

The antibiogram of organisms showed a high rate of resistance of aerobic bacteria to antibiotics which was statistically significant. However, the predominant organisms were most sensitive to erythromycin, cefuroxime and amoxicillin/clavulanic acid.