Sir,

We read with great interest the study "Bacteriological Studies in Osteomyelitis at Faisalabad" published in Feb. ‘88 issue of JPMA. Of 80 cases reported, E. Coil was the commonest infecting organism (37.5%) and none of the cultures showed mixed infection. We conducted a similar study on 125 cases of chronic osteomyelitis at Karachi in collaboration with the orthopaedic department II of Civil Hospital Karachi; few cases from Jinnah Postgraduate Medical Center and Sind Govt. Hospital Liaquatabad were also included. Majority of the patients belonged to 11-30 years age group; with more predominance of males and more involvement of fever and tibia. Of 125 cases single pure culturewasisolatedfrom89.S% and mixed from8.8%. No growth was found in 2 cases. E. Coli was the single commonest infecting organism (68.6%) followed by stept. pyogenes (7.4%) and pseudomonas aeruginosa (6.7%). Comparison is done between the bacteria isolated in the present study and that reported from Faisalabad (Table). It is interesting to note that usually gram positive bacteria were isolated from cases in whom haematogenous spread was the likely cause, while in open fractures and wounds, usually gram negative organisms were isolated, alongwith mixed infectioninfew cases. We think that apart from blood agar, Mac Conkey agar, chocolate agar and thioglycolate medium (anaerobic culture) should be used for isolation of organisms.

Yours faithfully,** Syed Iqbal Alam, Khurshed Ali Khan*, Ali Mohammad Ansari, Aqeel Ahmed
Federal Govt. Urdu Science College, Department of Microbiology,* University of Karachi and Department of Orthopaedics II, * Civil Hospital, Karachi.

1. Farooq, U., Ahmed, I.F. Bacteriological studies in Osteomyelitis at Faisalabad. JPMA., 1988;38:43.