Phenotypic characterization of pncA mutants of Mycobacterium tuberculosis.

We examined the correlation of mutations in the pyrazinamidase (PZase) gene (pncA) with the pyrazinamide (PZA) resistance phenotype with 60 Mycobacterium tuberculosis isolates. PZase activity was determined by the method of Wayne (L. G. Wayne, Am. Rev. Respir. Dis. 109:147-151, 1974), and the entire pncA nucleotide sequence, including the 74 bp upstream of the start codon, was determined. PZA susceptibility testing was performed by the method of proportions on modified Middlebrook and Cohn 7H10 medium. The PZA MICs were > or =100 microg/ml for 37 isolates, 34 of which had alterations in the pncA gene. These mutations included missense substitutions for 24 isolates, nonsense substitutions for 3 isolates, frameshifts by deletion for 4 isolates, a three-codon insertion for 1 isolate, and putative regulatory mutations for 2 isolates. Among 21 isolates for which PZA MICs were <100 microg/ml, 3 had the same mutation (Thr47-->Ala) and 18 had the wild-type sequence. For the three Thr47-->Ala mutants PZA MICs were 12.5 microg/ml by the method of proportions on 7H10 agar; two of these were resistant to 100 microg of PZA per ml and the third was resistant to 800 microg of PZA per ml by the BACTEC method. In all, 30 different pncA mutations were found among the 37 pncA mutants. No PZase activity was detected in 35 of 37 strains that were resistant to > or =100 microg of PZA per ml or in 34 of 37 pncA mutants. Reduced PZase activity was found in the three mutants with the Thr47-->Ala mutation. This study demonstrates that mutations in the pncA gene may serve as a reliable indicator of resistance to > or =100 microg of PZA per ml.

Clinical and programmatic mismanagement rather than community outbreak as the cause of chronic, drug-resistant tuberculosis in Buenaventura, Colombia, 1998.

SETTING: Buenaventura, Colombia. OBJECTIVE: To assess whether antituberculosis drug resistance was generated by poor management or community transmission. DESIGN: Treatment-failure and new tuberculosis (TB) patients identified between May 1997 and June 1998 were interviewed and their treatment histories reviewed. Bacteriologic testing, including drug susceptibility profiles (DSP) and DNA fingerprinting by restriction fragment length polymorphism (RFLP), was performed and human immunodeficiency virus (HIV) testing was offered. RESULTS: DSP and RFLP fingerprints were obtained for isolates from 34 of 64 treatment-failure patients; 25 (74%) were resistant to > or = one drug. Fifteen of the 25 patients consented to HIV testing; none were positive. An average of 2.8 major treatment errors per patient was identified. RFLP from the treatment-failure patients revealed 20 unique isolates and six clusters (isolates with identical RFLP); 4/6 clusters contained isolates with different DSP. Analysis of the RFLP from both treatment-failure and new patients revealed that 44/111 (40%) isolates formed 18 clusters. Four of 47 (9%) new patients had multidrug-resistant TB (MDR-TB). Eleven isolates belonged to the Beijing family, related to the MDR strain W. CONCLUSION: Drug resistance in Buenaventura results from both poor management and community transmission. Dependence on DSP to identify TB transmission is inadequate when programmatic mismanagement is common.

Pleomorphic hyalinized angiectatic tumor of soft parts.

Pleomorphic hyalinized angiectatic tumor of soft parts is a recently described neoplasm that most commonly affects the lower extremities. It is locally aggressive but has not been known to metastasize. This article presents a case of a softball-sized tumor on the dorsum of the foot that was identified as pleomorphic hyalinized angiectatic tumor of soft parts. Previously, it would have been misdiagnosed and treated as either a neurilemoma or a malignant fibrous histiocytoma.

Pseudo-outbreak of septicemia due to rapidly growing mycobacteria associated with extrinsic contamination of culture supplement.

Between April and December 1994, 23 blood cultures from human immunodeficiency virus-infected patients grew rapidly growing mycobacteria suspected to be Mycobacterium chelonae at a hospital in New Jersey. The isolates were later identified as M. abscessus. Several bacterial species, including M. abscessus, were cultured from an opened multidose supplement vial (BBL Septi-Chek AFB Supplement) that had been used for mycobacterial blood cultures. The M. abscessus isolates from case patients and the supplement vial had identical multilocus enzyme electrophoresis and antimicrobial susceptibility patterns. Finding a contaminated vial of supplement, together with the lack of a distinct syndrome in case patients, was consistent with a pseudo-outbreak.

The Evans calcaneal osteotomy: postoperative care and an evaluation on the metatarsus adductus angle.

A retrospective study of two aspects of the Evans calcaneal osteotomy with bone graft is presented. First, the postoperative casting time can be decreased significantly to 3 weeks of nonweightbearing and 3 weeks of weightbearing. Second, the metatarsus adductus angle remains relatively unaltered after the procedure.

The long arm V osteotomy for the fifth metatarsal.

A long arm V osteotomy of the fifth metatarsal is presented for the correction of tailor's bunions. The osteotomy is performed in the sagittal plane, perpendicular to the long axis of the metatarsal shaft. The long lateral arm increases the bone-to-bone contact and allows increased medial transposition. Three intrinsic locking mechanisms provide stability and eliminate the need for fixation. A 26-month retrospective analysis of 33 procedures is examined. Excellent or good results were obtained in 94% of the cases.

A quick guide for home use of inhalant medications.

The chronic and frequently recurring symptoms in an obstructive lung disease such as asthma often dictate a complex home treatment program for the child and family. In planning for discharge of an asthmatic child, the nurse assesses and evaluates a variety of treatment modalities.