Contributed by R Persad, MD, JC Dunn, MD, J Driscoll, PhD* and W Pasculle, ScD
* The David Axelrod Institute for Public Health, Wadsworth Center, New York State Department of Health
Published on line in December 1998
The patient is a 79-year-old white male who emigrated from Greece more than 25 years previously. He lived in rural Greece where he was exposed to farm animals and also had a history of household tuberculosis (TB) contact. More recently he has a history of superficial transitional cell carcinoma treated with BCG instillation.
In September 1997 he developed pain, swelling and decreased function of his left knee prosthesis which was implanted in 1995 following failure of his original knee implant performed 20 years ago. He was seen in California where the knee was aspirated. A culture of the aspirate was reported as containing Mycobacterium bovis, but the report was later revised to indicate M. tuberculosis. He was treated with Isoniazid, Ethambutol and Rifampin.
In March 1998 the prosthesis was removed and a Streptomycin impregnated spacer was placed. Synovial tissue was cultured and examined histologically. One month later he had reimplantation of left knee prosthesis.
Sections of soft tissue showed chronic synovitis with a histiocytic reaction and a rare focus of epithelioid granulomas (Images 01 and 02). Polyethylene and bone cement was also evident (Image 03).
Stains for acid-fast bacilli (Ziehl-Nielsen, Image 04) and fungi (Grocott) revealed no organisms.
A mycobacterium was isolated which gave a positive reaction with the Mycobacterium tuberculosis DNA probe and its identity was initially reported as "Mycobacterium tuberculosis complex". Susceptibility testing in liquid media revealed the isolate to be susceptible to Isoniazid, Rifampin, Ethambutol and Streptomycin, but resistant to Pyrazinamide. Because of its resistance to Pyrazinamide, the susceptibility of the organism to thiophene-2-carboxylic acid hydrazide (T2H) was measured. The organism was found to be susceptible confirming its identity as Mycobacterium bovis (Data not shown).
Image 05 shows the result of RD1 multiplex PCR assay with patient in lane 5.
Image 06 shows the reverse line blot results, patient in row 4.