Clinical significance, antimicrobial susceptibility and molecular identification of Nocardia species isolated from children with cystic fibrosis

ABSTRACT Nocardia is an opportunistic pathogen that causes respiratory infections in immunocompromised patients. The aim of this study was to analyze the epidemiology, clinical significance and antimicrobial susceptibility of Nocardia species isolated from eight children with cystic fibrosis. The isolated species were identified as Nocardia farcinica, Nocardia transvalensis, Nocardia pneumoniae, Nocardia veterana and Nocardia wallacei. N. farcinica was isolated in three patients and all of them presented lung affectation with a chronic colonization and pneumonia. N. farcinica showed resistance against gentamicin, tobramycin, cefotaxime, but was susceptible to trimethoprim-sulfamethoxazole and amikacin. N. transvalensis, which was isolated from two patients, showed an association with chronic colonization. N. transvalensis was resistant to tobramycin and amikacin, but susceptible to ciprofloxacin, trimethoprim-sulfamethoxazole and cefotaxime. N. veterana, N. pneumoniae and N. wallacei were isolated from three different patients and appeared in transitory lung colonization. N. veterana and N. pneumoniae were susceptible to imipenem, trimethoprim-sulfamethoxazole, amikacin, tobramycin, and cefotaxime. N. wallacei was resistant to amikacin, tobramycin, imipenem, and trimethoprim-sulfamethoxazole and susceptible to ciprofloxacin and cefotaxime. All the isolates were identified up to species level by 16S rRNA gene sequencing. The presence of Nocardia in the sputum of patients with cystic fibrosis is not always an indication of an active infection; therefore, the need for a treatment should be evaluated on an individual basis. The detection of multidrug-resistant species needs molecular identification and susceptibility testing, and should be performed for all Nocardia infections.

Nocardial infections: report of 22 cases

Twenty-two cases of nocardial infections were diagnosed in our city between 1977- 1998. All patients whose clinical specimens showed Nocardia spp. at Gram stain, which were further confirmed by culture, were selected to be included in the study. Data from patients who were cured were compared with those from patients who died by statistical tests using EPIINFO version 6.04 software. Six isolates were identified as Nocardia asteroides complex, one as Nocardia asteroides sensu stricto and other as Nocardia brasiliensis. We had 17 cases of lung nocardiosis, being one out of them also a systemic disease. Other four cases of systemic nocardiosis were diagnosed: nocardial brain abscesses (one); nocardiosis of the jejunum (one); multiple cutaneous abscesses (one); and a case of infective nocardial endocarditis of prosthetic aortic valve. One patient had a mycetoma by N. brasiliensis. Fifteen (68.2 percent) out of 22 patients were immunosuppressed, being most (93.3 percent) by high-doses corticotherapy. Mortality by nocardial infection was 41 percent; mortality of systemic nocardiosis was 60 percent. Nocardiosis has a bad prognosis in immunosuppressed patients and also in non-immunosuppressed patients if the diagnosis is delayed. We propose that the delay in diagnosis should be examined in larger series to document its influence in the prognosis of the disease.

São apresentados 22 casos de infecção por Nocardia species entre 1977 e 1998, apresentando-se seu quadro clínico e evolução. Todos os pacientes cujos espécimes clínicos mostraram microorganismos sugestivos de Nocardia spp. à coloração de Gram, confirmados posteriormente por cultura, foram incluídos no estudo. Os dados dos pacientes que obtiveram cura foram comparados com aqueles dos pacientes que foram a óbito pelo programa EPIINFO versão 6.04; nível de significância menor que 5 por cento foi considerado estatisticamente significativo. Foram obtidos 22 casos de infecção por Nocardia spp.: seis isolamentos identificados como Nocardia asteroides complex, um como Nocardia asteroides sensu stricto e outro como Nocardia brasiliensis, enquanto os restantes foram identificados como Nocardia spp. Tivemos 17 casos de nocardiose pulmonar (um com disseminação). Tivemos outros quatro casos de nocardiose sistêmica: múltiplos abscessos cerebrais (um); endocardite infecciosa de prótese valvular aórtica (um); nocardiose de intestino delgado (um); abscessos cutâneos múltiplos por Nocardia spp (um). Um paciente apresentou micetoma por Nocardia brasiliensis. Imunossupressão esteve presente em 15 pacientes (68,2 por cento), predominantemente por corticoterapia (93,3 por cento). Nossa mortalidade foi 41 por cento; a mortalidade dos pacientes com nocardiose sistêmica foi de 60 por cento. A nocardiose tem pior prognóstico em pacientes imunossuprimidos e em pacientes com nocardiose sistêmica.

Nocardia asteroides en absceso pulmonar interpretado como de origen tuberculoso: caso fatal / Nocardia asteroides in a pulmonary abscess considered to be of a tuberculous origin: fatal case

Se informa el hallazgo de cultivos puros de n. asteroides a partir de la colección purulenta obtenida por drenaje quirúrgico de un absceso en base pulmonar derecha, de 6 cm de diámetro, en una niña de 13 años de edad con desnutrición de segundo grado y antecedentes de tuberculosis. Lo prolongado de la evolución diagnóstica, el cuadro infeccioso inespecífico, y el probable deterioro inmunológico pudieron haber producido cierta demora en el diagnóstico y por lo tanto para el desenlace fatal

Nocardiosis pulmonar primaria: presentación de un caso

Informamos el caso de una mujer de 46 años con tos no productiva, disnea CF II, hipoxemia y pérdida de peso. Los Rx de tórax mostraban opacidades de tipo insterticial bilaterales. Se le diagnostica nocardiosis pulmonar primaria mediante cultivo del lavado broncoalveolar y de la biopsia pulmonar a cielo abierto. Presentamos los principales hallazgos clínicos, radiológicos, bacteriológicos y de patología.