MICROBIOLOGICAL EPIDEMIOLOGY AT CHRIS HANI BARAGWANATH ACADEMIC HOSPITAL: POLYMICROBIAL OSTEOMYELITIS ANALYSIS

Most patients treated at our clinical setting present during chronic osteomyelitis stage, which is anecdotally likely to be poly-microbial. Adults with poly-microbial infection have a predilection for gram-negative bacteria and anaerobes, a scenario that hypothetically leads to a higher morbidity of poly-microbial osteomyelitis following trauma. Our study looks into the epidemiology of poly-microbial osteomyelitis treated at our Tumour and Infection unit.Retrospective study of patients treated for osteomyelitis from 2016 to 2020. Records of eligible patients were retrieved for examination. Demographics such as age, sex and race were recorded. Clinical presentation, organisms cultured, including their anti-microbial sensitivities were documented.There were 63 participants in the study. 31 (49.21%) had mono-microbial osteomyelitis with 32 (50.79%) having poly-microbial osteomyelitis. Majority of the poly-microbial patients presented with a sinus (68.75%) mostly located in the tibia (50%).Multiple mixed pathogens (both gam-positive and gram-negative) were cultured in our patients and this comprised 71.21% of the total bacteria cultured. Staphylococcus Aureus was the commonest bacteria (30%) isolated, followed by Enterococcus faecalis (12%). The commonest gram-negative bacteriae cultured was Enterococcus cloacae (10%) followed by Acinetobacter baumannii (7%). Most enterobacteriacae species were sensitive to Ertapenem and Ceftazidime.A slightly higher incidence of poly-microbial osteomyelitis was found in our study than that reported in literature. Furthermore, our study demonstrated a wide variety of organisms found in poly-microbial osteomyelitis, with a large contribution made by gram-negative anaerobic rod-shaped bacteria