Rapid molecular diagnosis of tuberculosis and other mycobacteriosis in smear-negative clinical specimens

Delay in diagnosis of pulmonary and other forms of tuberculosis (TB) can be fatal, particularly in HIV-infected patients. Hence, techniques based on nucleic acid amplification, which are both rapid and of high specificity and sensitivity, are now widely used and recommended for laboratories that diagnose TB. In the present study, diagnostic methods based on mycobacterial DNA amplification were evaluated in comparative trials alongside tradicional bacterial methods, using negative smear samples from patients with clinically-suspected TB (sputum samples from 25 patients with suspected pulmonary TB, urine samples from two patients with suspected renal TB and cerebrospinal fluid samples from one patient with suspected meningeal TB). A specificity of 100% was achieved with DNA amplification methods and tradicional culture/identification methods, in relation to clinical findings and treatment results. For the smear-negative sputa, conventional PCR for M.tuberculosis was positive in 62% of suspected lung TB case, showing the same sensitivity as bacterial identification. Both techniques failed in the detection of extra-pulmonary samples. Nested PCR showed, after species-specific amplification, a sensitivity of 100% for M. avium and 85% for M. tuberculosis. For extra-pulmonary smear-negative samples, only Nested PCR detected M. tuberculosis and all cases were confirmed clinically. Nested PCR, in which two-step amplification reactions are performed, can identify the two most important mycobacteria in human pathology quickly and directly from clinical spicimens

Isolation of Mycobacterium gordonae from poultry slaughterhouse water in SÒo Paulo State, Brazil

Water samples (24 untreated water, 12 treated water and 24 served water) used in different stages of the slaughter process were examined to identify a possible source of pathogenic mycobacteria. The isolates were identified based on microscopy, morphological and biochemical features, mycolic acid analysis and molecular method--PCR-restriction-enzyme analysis. Eighteen mycobacterial strains were isolated from 60 water samples: 11 from untreated water, 5 from treated water and 2 from served water. All mycobacteria isolated were identified as Mycobacterium gordonae and showed the following PRA genotypes: III (27.8

) and V (33.3

Enteroparasitosis en escolares de dos unidades educativas rurales del Municipio La Cañada, Estado Zulia Venezuela / Enteroparasitosis in school children from two educatives rurals units of the Municipality La Cañada, Zulia State Venezuela

El objetivo de la presente investigación fue determinar la prevalencia de la parasitosis intestinales, en los escolares de las unidades educativas rurales "Cacique Mara" y "Puerto Páez", ubicadas en la Parroquia Potreritos, Municipio La Cañada de Urdaneta del Estado Zulia. Se procesaron un total de 84 muestras de heces correspondientes entre 7 y 12 años, las cuales fueron sometidas a los métodos coproparasitológicos de: examen al fresco con solución salina fisiológica y lugol, técnica de concentración con formol-acetato de etilo y técnica de recuento de huevos de kato-kats. Los resultados obtenidos demuestran una elevada prevalencia de enteroparásitos (74,6 por ciento para Cacique Mara y 92,0 por ciento para Puerto Páez); así como un marcado predominio del poliparasitismo sobre el monoparasitismo. No se observó diferencia significativa de susceptibilidad a las parasitosis por edad o por sexo dentro de cada escuela o entre ambas unidades educativas. Las especies de enteroparásitos patógenos más frecuentes en los escolares de Cacique Mara y Puerto Páez fueron: T.trichiura (32,2 por ciento y 80,0 por ciento); A.lumbricoides (5,1 por ciento y 52,0 por ciento); G.lamblia (22,0 por ciento y 36,0 por ciento) y E.histolytica 85,1 por ciento y 16,0 por ciento). Al analizar la intensidad de infestación por geohelmintos, se observó que el mayor por centaje de los casos de Trichuriasis y Ascaridiasis se correspondían con cuadros "leves", restando sólo unos pocos casos "moderados" o "severos"; lo que confirma la tesis de que las cargas parasitarias de helmintos en los individuos ocurre en forma de agregados