[Nocardia spp. isolated from immunocompromised patients in Trakya University Medical Faculty Hospital and their antibiotic susceptibilities]

Abstract

The aims of this study were the isolation and identification of Nocardia spp. from clinical samples of immunocompromised patients and patients with underlying diseases, and determination of antibiotic susceptibilities of the isolates. A total of 234 patients (172 male, 62 female; mean age: 58.6 +/- 15.9 years) of whom 126 (53.8%) with malignancy and 108 (46.2%) with other underlying diseases (pulmonary diseases, rheumatologic disorders, diabetes mellitus, chronic renal disfunction, cerebrovascular disorders and malnutrition) were included to the study. Biochemical characteristics, growth properties and antibiotic susceptibility patterns were used for the identification of the isolates. The distribution of specimens were as follows; sputum (124), tracheal aspirate (54), pleural fluid (27), bronchoalveolar lavage (23), abscess material (7) and lung biopsy (1) material. Nocardia spp were isolated from four out of 234 patients (1.7%), and two of them were identified as N. farcinica, one as N. asteroides and one as N. otitidiscaviarum. All of the four patients have had predisposing factors (hepatocellular carcinoma/diabetes mellitus; antiphospholipid syndrome/steroid use; nephrotic syndrome/ steroid use; chronic obstructive lung disease/lung cancer?), with a mean age of 52.5 years, and of them two were male. Nocardiosis has been presented as pulmonary infection in two of the cases, and brain and soft tissue abscesses in one of each patient. Kirby-Bauer disk diffusion, E-test and broth microdilution methods were used in order to detect the antibiotic susceptibilities of the strains. All isolates were found susceptible to imipenem and amikacin and resistant to erythromycin and ampicillin. One N. asteroides isolate was found susceptible to trimetoprim-sulphamethoxazole (TMP-SMX), whereas two N. farcinica and one N. otitidiscaviarum strains were resistant. The antibiotics to which N. farcinica isolates were susceptible were ceftriaxone and cefotaxime. As a result, since there is an increase in the number of immunocompromised patients recently, Nocardia spp. should be considered in such patients, and TMP-SMX should be used with care for empirical therapy.