Nocardia is a Gram-positive, aerobic branched actinomycete; it is a ubiquitous soil saprophyte. Nocardia as a cause of septic arthritis is very unusual. We report a case of Nocardia cyriacigeorgica arthritis in the right knee in a 38-year-old woman who was being treated with systemic corticosteroids for systemic lupus erythematosus and was on haemodialysis. The presumptive bacterial identification of the Nocardia genus was made by Gram and acid-fast staining, growth characteristics, colonial morphology and antibiotic resistance. Identification was later confirmed by PCR and sequence determination of the 16S rRNA gene. The patient was treated successfully with trimethoprim-sulfamethoxazole for 12 months. To the best of our knowledge, this is the first detection of N. cyriacigeorgica in Tunisia and the first Tunisian report of Nocardia arthritis. This finding emphasizes the importance of optimizing conditions of bacterial isolation, especially for immunocompromised patients, to identify less common organisms and initiate early appropriate treatment.
Stenotrophomonas maltophilia (S.maltophilia) is an aerobic, non-fermentative, Gram-negative bacillus. It behaves like an opportunistic pathogen affecting individuals with severe debilitation or immunosuppression. In peritoneal dialysis (PD), S.maltophilia peritonitis is associated with a pejorative prognosis and loss of peritoneal catheter in front of its common resistance to different groups of antibiotics including beta-lactams, aminoglycosides and fluoroquinolones.
Primary hyperoxaluria type 1 (PH1), is a rare and heterogeneous disease and one of major causes of renal insufficiency in Tunisia, caused by mutations in the AGXT gene. 33-34InsC mutation, was mainly described in children with a severe clinical feature leading to early death, but it was uncommonly reported in adult patients. Common mutations in AGXT were tested using PCR/RFLP technique in 111 patients (68 adult, 43 children) with suspected PH1. We described 16 cases (eight adult and eight children) with a 33-34InsC mutation with a median age of 24 years [6 months - 73 years]. All children were in end stage renal disease (ESRD) at the median age of 3 years due to lithiasis and/or nephrocalcinosis. Unfortunately, 75% of them died with a median age of 2.5 years. For the majority of adults only spontaneous elimination of urolithiasis were noted, 37.5% preserved until now a normal renal function and 62.5% of them reached ESRD at the median age of 55.8 ± 12.31 years old. In this study 33-34InsC mutation gives a controversial clinical effect in children and adults. The implication of other genetic and/or environmental factors can play a crucial role in determining the ultimate phenotype.
