A sample of 124 isoniazid (INH)-resistant and 88 susceptible strains of Mycobacterium tuberculosis complex from south, central, and west Africa was analyzed by direct sequence analysis and PCR-restriction fragment length polymorphism analysis of their catalase-peroxidase (katG) genes. Point mutations at codon 315 were found in the genomes of 64% of INH-resistant strains, but no complete deletions were identified. Mutations at codon 463 were independent of INH resistance and were linked to the geographic origins of the strains.
Mycobacterium africanum is a pathogen found in tuberculosis patients in certain parts of Africa and is a member of the Mycobacterium tuberculosis complex. Biochemically, strains of M. africanum exhibit a high degree of variability, with some tendency to cluster according to their geographical origin. To investigate whether this phenotypic variability is reflected at the genetic level, we performed DNA fingerprint analysis of strains isolated from patients with pulmonary tuberculosis in Uganda and Sierra Leone. IS6110 DNA fingerprinting was carried out by the mixed-linker PCR method. A total of 138 strains of M. africanum were analyzed: 42 isolates from Uganda and 96 isolates from Sierra Leone. With few exceptions, the resulting DNA fingerprint patterns grouped together according to their country of origin. A striking lack of variability of DNA fingerprints was found for strains from Sierra Leone, where 70 of 96 isolates (61.5%) fell into clusters. The two largest clusters accounted for 41.7% of all isolates and differed by only one band, as confirmed by standard DNA fingerprinting. In contrast, only two clusters (7.1%) with two and three isolates, respectively, were found for M. africanum isolates collected in Uganda, and three of the DNA fingerprints contained fewer than seven bands. Strains of M. tuberculosis collected and processed during the same time period were highly variable in both countries. Our results support the concept of geographically defined subtypes of M. africanum. In addition, they demonstrate that natural geographic differences in the variability of IS6110 DNA fingerprints within the M. tuberculosis complex must be considered if this technique is used for epidemiologic studies.
We report on a neonate presenting with polyhydramnios; macrosomia; macrocephaly; visceromegaly including bilateral nephromegaly, hepatomegaly, cardiomegaly; thymus hyperplasia; cryptorchidism; generalized muscle hypotonia; and a distinctive facial appearance. The clinical course was marked by severe neurodevelopmental deficits combined with progressive respiratory decompensation leading to death at the age 6 months. Magnetic resonance imaging (MRI) disclosed a generalized cerebral atrophy with a marked deficit of the white matter. Renal ultrasound and MRI showed markedly enlarged kidneys with multiple small cystic lesions, a pattern indistinguishable from polycystic kidney disease. The postmortem kidney biopsy revealed dysplastic changes, microcysts, and a focal nephrogenic rest, characteristic features of the Perlman syndrome. In children with fetal gigantism, renal abnormalities, and neurological deficits, Perlman syndrome should be considered and may be confirmed by kidney biopsy.
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