1354. Nocardia bejingensis: A Novel Isolate Affecting Immunocompromised Patients in the United States.

Background Nocardia species can cause localized or disseminated disease in humans. Infection results from direct inoculation or inhalation. In recent years, several new species have been identified via molecular methods. Further speciation is crucial as each organism has its own spectrum of disease and unique antibiotic susceptibility patterns. Immunosuppression, alcoholism, and certain lung diseases are well-established risk factors for nocardiosis. In fact, cases have incremented in association with increasing population of immunocompromised hosts as well as improved methods for detection and identification. Thus, Nocardia species may be considered opportunistic pathogens. Nocardia bejingensis was first isolated in 2001 by Wang et al from sewage soil in China. The first human infections were reported in Asia. Subsequently, cases were reported in Europe and a few cases have been described in the United States but it has been infrequently cited in the literature. Thus, not much is known about its spectrum of disease. Methods The primary objective of this study was to determine the risk factors and clinical manifestations of Nocardia bejingensis infection via retrospective chart review of 6 cases identified in Tampa General Hospital and Moffitt Cancer Center within a 5-year period. We aimed to evaluate the treatment used and the antibiotic susceptibility patterns of the isolates. Results All patients were immunocompromised (1/3 HIV/AIDS, 1/3 hematologic malignancy, 1/3 solid-organ transplant). Most were male (67%) and mean age of 48. The majority had lung involvement (67%). Thecal sac infection and femur osteomyelitis (OM) were atypical manifestations. Localized disease predominated. Combination therapy was preferred. Trimethoprim-sulfamethoxazole (TMP-SMX), Ceftriaxone, and carbapenems were mostly used. All isolates were susceptible to TMP-SMX. See Table 1. Conclusion This case series depicts clinical features, risk factors, and epidemiology of Nocardia bejingensis infections. Our observations suggest that it is a novel pathogen in the United States, affecting mainly immunocompromised hosts. Early detection, appropriate antibiotics, and surgery were keys in successful management. However, further studies are needed to further elucidate its pathogenesis. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]