Microbiological and clinical data analysis of 32 patients with Nocardia infections in Yantai

Background/aim: Nocardia is an opportunistic pathogen that mostly affects hosts with immune deficiencies. Recently, the widespread use of immunosuppressive agents and antitumor drugs has led to an increasing number of Nocardia infections being reported. However, it is difficult to confirm this diagnosis owing to the slow growth of the bacterium and its complex resultant clinical manifestations, potentially delaying treatment and increasing mortality. Thus, further knowledge on the clinical characteristics of Nocardia infection is required. Hence, this study aimed to review the demographics, comorbidities, clinical presentation, microbiology, treatment, and outcomes of Nocardia infections in Yantai. Materials and methods: This is a retrospective study including 32 patients identified to have Nocardia infection from the Yantai Yuhuangding Hospital. The relevant patient samples were collected by two researchers, while the other researchers analyzed the relevant data. Results: The male to female ratio among the 32 patients was 3:5, and 23 patients (71.9%) were immunocompromised. Pulmonary sites of infection were the most common (65.6% of patients). N. brasiliensis infections were present in 25.0% and N. asteroides infections were present in 21.9% of patients. Because of limited biotechnological resources, Nocardia spp. in 50.0% of cases were not classified. The TMP-SMX resistance rate among isolates was 9.4%. All isolates were susceptible to amikacin, ceftriaxone, and imipenem. Conclusion: In Yantai, immunocompromised patients predominate among cases of Nocardia infection. The rate of occurrence was higher in females than in males. Because of potential TMP-SMX resistance, treatment for Nocardia infection should be based on drug susceptibility or should include combination therapy.