Pyogenic Anaerobes of Wound Infection and the Associated Risk Factors among Patients in Uyo, Southern Nigeria

Aims: Anaerobic causes of pyogenic wound infection are not usually investigated due to difficulties in cultural techniques, lack of equipment and technical man-power. Therefore, this study aimed to investigate the anaerobic bacteria agents of pyogenic infection and the associated risk factors among patients in a tertiary hospital.

Study Design: This was a descriptive cross-sectional study conducted at the University of Uyo Teaching Hospital, Uyo and carried out on 136 wound samples from patients. These samples were collected from all consented patients with pyogenic wound infection that met the inclusion criteria.

Place and Duration of Study: The study was conducted at Uyo, the capital city of Akwa Ibom State, Nigeria between April and October, 2018.

Methodology: Deep wound swabs or aspirated pus samples were collected and inoculated into fresh 25% Sheep Blood Agar plate and incubated in an anaerobic jar containing anaerobic indicator and Gas-pak at 37oC for 48 – 72 hours Identification of isolates was performed following standard procedures. Data were obtained through a well- structured questionnaire and analyzed using SPSS software.

Results: Of the 136 samples collected, 127 yielded microbial growth with a total of 202 isolates which included 50 and 2 pure growths of aerobes and anaerobes respectively and 75 combined growths of aerobes and anaerobes. Overall, more aerobes (125) were isolated when compared to the anaerobes (77). Nevertheless, the predominant anaerobe was B. fragilis 26(33.8%). There was a statistical significant relationship between the age of the patient and infection by gram- positive anaerobes (p = 0.002).

Conclusion: Bacteriodes fragilis is mainly involved in anaerobic pyogenic wound infections in Uyo, however, only the age of the patient was found to be a factor in the prevalence of infection by gram-positive anaerobes.