Emergence of co-infection with Cryptococcus neoformans and Acinetobacter baumannii in older people with systemic lupus erythematosus

Abstract

Systemic lupus erythematosus (SLE) is a common autoimmune disease affecting various organs. Cryptococcus neoformans, an environmental yeast that is heavily dependent on the complement cascade for natural host defense, is produced via inhalation in immunocompromised patients. The fungal pathogen, C. neoformans, can cause life-threatening infections in patients with SLE. Acinetobacter baumannii is a nosocomial pathogen that causes healthcare-associated infections, particularly in immunocompromised and critically ill patients. However, reports of co-infection with C. neoformans and A. baumannii in patients with SLE are scarce. We report an interesting case of co-infection with C. neoformans and A. baumannii in an 85-year-old man presented with cough, expectoration, chest tightness, and shortness of breath five months after diagnosis of SLE. The patient recovered gradually after 18 days of antimicrobial therapy. Coinfection with C. neoformans and A. baumannii in patients with SLE is rare, difficult to diagnose early, and has a high mortality rate. Accurate diagnosis and timely treatment are lifesaving.

Keywords: Acinetobacter baumannii; Cryptococcus neoformans; Co-infection; Pneumonitis; Systemic lupus erythematosus.

Fig. 1

(A-B) On admission, the patient underwent a pre-treatment plain chest computed tomography (CT) scan, revealed signs of a chest infection, including multiple patchy and flocculent high-density shadows in both lungs with blurred edges, as well as bilateral pleural effusion, predominantly in the lower lung regions. (C-D) The results of chest CT uncovered that the pneumonitis and pleural effusion were reduced after treatment. (E-F) The 1-month follow-up post discharge, the results of chest CT showed no significant abnormalities in both lungs

Fig. 2

Cryptococcus neoformans obtained from the patient’s blood sample was respectively cultured on blood agar plate (A), Sabouraud dextrose agar plate (B), and Candida chromogenic agar plate (C)

Fig. 3

(A) The microscopic examination of the colonies of Cryptococcus neoformans showed purple round spheroids by Gram staining method (100×). (B) Microscopy revealed that the colonies of C. neoformans. contained round thallus with a ring of transparent hypertrophic capsule on its outer axis with reflective spores and no hyphae by ink staining method (100×)