Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.

Espondilitis tuberculosa ("Mal de Pott"): presentación de un caso y revisión bibliográfica / Tuberculous spondylitis (Pott's disease): case report and review of the literature

Tuberculosis of the spine (Pott' disease), is an uncommon evento of extrapulmonary tuberculosis and usually occurs in the absence of extraspinal infection. We report a 24 year-old-man assisted in Córdoba, City (Argentina). Patient arrived at the hospital with mild lumbar pain, thigh's hyperesthesia an patellar hyporreflexia, both in the right side, without general manifestations. X-ray and CT scanning showed severe structural domage of vertebral bodies of the fourth, an fifth lumbar (L4, L5) and first sacral (S1) vertebrae. In addition, paraspinal abscess with extension up to psoas muscle was observed. Mycobacterium tuberculosis was isolated by culture of specimens obtained by aspiration from affected area, fourty days after admission. Patient was treated for nine months with four drugs (Isoniazid, Rifampicine, Pyrazinamide and Ethambutol). Then, the spine was surgically stabilized. During a follw-up of ten years, patient improved progressively. We point out that Pott' disease should be suspected in all cases with vertebral osteomyelitis and negative bacteriological test for common bacteria.

Evaluation of the histopathological hepatic lesions and opportunistic agents in Brazilian HIV patients / Avaliação das alterações histológicas hepáticas e infecções oportunistas em pacientes brasileiros infectados pelo HIV

INTRODUCTION: to evaluated the type histopathological hepatic lesions and opportunistic agents in Brazilian HIV-infected patients. METHODS: we examined 52 percutaneous liver biopsies of 50 HIV-infected patients who had at least two of the following conditions: fever of unknown origin, unexplained severe emaciation, hepatomegaly or abnormal liver chemistry. The specimens were cultured for mycobacteria and fungi and stained by standard procedures. RESULTS: reactive patterns, granulomatous hepatitis and chronic active hepatitis were verified in 28 (54 percent), 11 (21 percent) and 8 (15 percent) of the patients respectively. Opportunistic infections were diagnosed in 18 (36 percent) patients: mycobacteria in 12 (24 percent), Cryptococcus neoformans in 5 (10 percent) patients and mycobacteria and yeast was isolated from the same liver fragment in one patient. CONCLUSIONS: mycobacteriosis was the most common opportunistic infection and liver tissue culture is an important method to detect opportunistic agents, even in the absence of histological lesions.

INTRODUÇÃO: avaliar os tipos de lesões histopatológicas e infecções oportunistas de Brasileiros infectados pelo HIV. MÉTODOS: Foram analisadas 52 biópsias hepáticas percutâneas de 50 pacientes que apresentavam pelo menos duas das alterações: febre de origem indeterminada, emagrecimento inexplicado, hepatomegalia ou anormalidades na bioquímica hepática. O fragmento de tecido hepático foi submetido a histopatologia por métodos habituais e cultura para micobacteria e fungo. RESULTADOS: padrão reacional, hepatite granulomatosa e hepatite crônica ativa foram encontrados em 28 (54 por cento), 11 (21 por cento) e 8 (15 por cento) dos pacientes respectivamente. Infecções oportunistas foram diagnosticadas em 18 (36 por cento) dos pacientes: micobacteria em 12 (24 por cento), Cryptococcus neoformans em 5 (10 por cento) pacientes e micobacteria e fungo foram isolados no mesmo fragmento em um paciente. CONCLUSÕES: micobacteriose foi a infecção oportunista mais comum e a cultura de tecido hepático foi um importante método para detecção de infecções, mesmo na ausência de lesões histológicas.

Tuberculosis generalizada: a propósito de un caso / Generalized tuberculosis: case report

La tuberculosis extrapulmonar supone el 10-20 por ciento del total de tuberculosis que padecen los enfermos inmunocompetentes. En los casos de tuberculosis extrapulmonar existe un foco primario pulmonar desde donde se puede producir un diseminación, bien por contigüidad, vía linfática o por vía hematógena, siendo esta última vía la causante de la mayoría de las tuberculosis extrapulmonar.

Mycobacterial skin infections: comparison between histopathologic features and detection of acid fast bacilli in pathologic section.

BACKGROUND: Detection of acid fast bacilli (AFB) in chronic granulomatous inflammation is an important clue for mycobacterial infection. DESIGN: A retrospective review of 104 pathologic sections (from 1994 to 2001) of suspected cases of mycobacterial (tuberculous and nontuberculous) skin infections to study histopathologic features and the correlation with the presence of AFB in the section was performed. RESULTS: All cases showed granulomatous inflammations that can be categorized into 4 types: mixed cell, suppurative, tuberculoid and palisading granuloma. AFB was found in 32 sections (30.77%). Ninety five specimens from 104 specimens were simultaneously cultured. AFB positive cases yielded higher positive cultural results, 17 from 29 cases (58.62%) compared to the AFB negative group, 23 from 66 cases, (34.85%). Mixed cell granuloma was the most common histologic feature, but suppurative granuloma was the most common histological feature (56.25%) in which AFB could be found, which was statistically significantly different from other types of granuloma. Tuberculoid granuloma was more common in the AFB negative group (20.83%) compared to the AFB positive group (9.37%) but the difference was not statistically significant. In cases that AFB could not be found, the inflammation tended to be located in the upper half of the dermis. CONCLUSION: AFB can be more frequently detected in suppurative granuloma that might be located in any portion of the dermis. This finding was not species specific.

Vólvulo de sigmoides asociado a tuberculosis peritoneal / Sigmoid volvulus associated to peritoneal tuberculosis

Actualmente se considera que un tercio de la población humana se encuentra infectado por Mycobacterium tuberculosis. La tuberculosis mimetiza toda una variedad de padecimientos y, en el caso de su variante peritoneal que comprende del 0.7 al 2 por ciento de todos los casos registrados, puede comportarse clinicamente como cualquier otra patología abdominal. Por su parte, el vólvulo de sigmoides constituye una entidad con amplias variaciones geográficas, con una prevalencia de 0.2 por ciento en Occidente y con una tasa de mortalidad considerable del 30 por ciento. De etiología incierta, se relaciona con variaciones anatómicas, régimen dietético, constipación crónica, procesos inflamatorios localizados, enfermedades neurológicos, adherencias posquirúrgicas, embarazo, toxinas y enfermedades metabólicas. Presentamos un caso clínico en el que se conjugan estas dos patologías

Caracterización de la infección experimental con Mycobacterium lepraemurium en dos cepas de ratones / Development of experimental infection with Mycobacterium lepraemurium in two strains of mice

Se desarrolló un modelo de lepra experimental e 2 cepas de ratones, CB/J y CBi, en base: a) el estudio histológico del granuloma en la pata trasera, 200 días despues dela inoculación con 0,30 micronl de mycobacterium lepraemurium (6 x 10**8 ML/ml); b) la evaluación en el granuloma, de linfocitos T, identificados con la técnica inmunohistoquimica de alfa-naftil acetato de estearasa; c) la diseminación a distancia de la infección. La cepa CBA/J, de baja resistencia, presentó un cuadro histológico compuesto por células vacuoladas BAAR positivas sin infiltración linfocitaria, escasa presencia de linfocitos T y generalizada y abundante diseminación a distancia (símil lepromatosa humana. La cepa CBi, de mediana a alta resistencia, mostró en el granuloma de la pata (en un 30-40% de los animales), un cuadro histológico compuesto por células vacuoladas e infiltrado linfocitario, presencia abundante de células T y poca diseminación a distancia (símil "borderline" humana). Las dos cepas presentan diferenetes susceptibilidad a un desafío único con la micobacteria, y pueden ser de utilidad para conocer los componentes inmunogenéticos de esa condición, mediante selección y cruzas adecuadas, así como ralizar, en los ratones CBi, ensayos de inmunoprotección que apoyen los estudios de vacunación en lepra humana

Studies on the Mycobacteria Isolated from Soil

Acid-fast microorganisms were isolated from 240 soil samples collected at two areas, Hiroshima, Japan and Seoul, Korea. The biological and biochemical characteristics of the isolated mycobacteria were tested and compared with those of 36 reference mycobacteria Strains. The isolation rate and distribution of these mycobacterial species from soil were compared using three kinds of media with emphasis on the two methods of isolation between the different geographical areas. One Strain from each of the 10 species among atypical mycobacteria isolated from soil in both areas was inoculated into ddY mice and the pathogenicity compared with that of Mycobacterium tuberculosis H37Rv up to 6 weeks. Susceptibility of the reisolated acid-fast bacilli to antimycobacterial agents was tested in vitro. Antibody responses against various mycobacterial antigens were tested using lepromatous type and tuberculoid type patient sera by the agar gel immunodiffusion. 1) No significant differences in the distribution of acid-fast bacilli were observed between soil samples from the two regions. 2) Rapid growers were by far the most frequent acid-fast bacilli isolated while no photochromogens were isolated from these soil samples. In addition, a minimal number of fastidious mycobacteria were isolated but not cultivable in subcultures. 3) Some of these soil acid-fast bacilli were capable of inducing only transient bacteriological and pathologic changes in mouse organs. 4) Acid-fast bacilli reisolated from organs of these infected mice were, in general, found to be resistant to antimycobacterial agents. 5) M. scrofulaceum antigen showed a precipitation reaction in agar gel immunodiffusion with the highest number of sera from leprosy patients.