Aerobic microbiological profile of contigious focus osteomyelitis.

ABSTRACT

Background: Bone and Joint infections are painful for patients and frustrating for them and their doctors. Eradication of infection from bone is difficult since there is fibrosis and low vascularity due to chronic inflammation where antibiotics are difficult to reach. Such infections tend to persist until the infected biomaterial and the adjacent tissues are removed. Osteomyelitis is also a disease in transition with ongoing changes in predisposing factors, causative organism and treatment. The relative frequency of haemetogenous osteomyelitis and relapsing osteomyelitis continues to decline, conversely the incidence of bone infections related to joint replacements, complex surgical interventions and wound infections are increasing. Factors involved in choosing the appropriate antibiotics include infection type, infecting organism, sensitivity results and antibiotic characteristics. Objective: To know microbiological etiology in different types of osteomyelitis in our region. Material & Methods: Specimens were collected from clinically and radiologically diagnosed 97 patients of Contiguous focus osteomyelitis, In cases of contiguous focus osteomyelitis presenting with sinus tract, deeper material from sinus tract was collected, wherein surgical intervention was required operative biopsy from bone or scrapping from prostheis was collected. Tissue biopsy/ sequestrum obtained were homogenized with sterile mortar and pestle with little sterile broth, for microscopic examination and inoculation. Pus, aspirate, sinus swab were directly used for microscopic examination and Inoculation. All the samples were inoculated on sheep blood agar and MacConkey agar. The plates were examined for growth after 24 hrs. Any growth was identified by colony characters & standard biochemical tests. Results: Staphylococcus aureus was etiological agent (42.05%) in majority of contiguous focus osteomyelitis. Enterobacteriaceae organisms and Pseudomonas aeruginosa were also found to be common agents (11.36% each).Poly-microbial etiology was evident in 15 (17.04%) cases In all 9 cases of contiguous focus osteomyelitis secondary to vascular insufficiency poly-microbial flora was seen. Conclusion: Bone infections that originate from contiguous soft tissue infections can have various etiologies and may even be due to mixture of bacteria from multiple genera Staphylococcus aureus is most common etiology.