Lelliottia amnigena and Pseudomonas putida Coinfection Associated with a Critical SARS-CoV-2 Infection: A Case Report

Lelliottia amnigena is a Gram-negative facultative anaerobic bacillus identified from water sources and later from food (onions, cream, unpasteurized milk, and Spanish pork sausages), which, under certain circumstances, can cause infections in humans, especially in immunocompromised patients. Few cases of human infections have been reported in the literature, such as endophthalmitis, urinary tract infection, pyonephrosis, and sepsis. We describe the case of a 69-year-old Caucasian male patient who lives in an urban environment and presents himself to the emergency department with chills, fever, myalgias, marked physical asthenia, dry cough, dyspnea, symptoms for which he is tested and confirmed with SARS-CoV-2 infection using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) from nasal and pharyngeal swabs, after being admitted the same day (25 May 2023) to the Infectious Diseases Clinic from the County Clinical Emergency Hospital Sibiu, Romania. At the time of admission, a pulmonary computerized tomography (CT) scan was performed, which revealed a severity score of 10 out of 25. In the second week of the disease, the patient presents with hemoptysis, from which bacteriological examinations are carried out, and Pseudomonas putida and Lelliottia amnigena are identified. The evolution was slowly favorable under antiviral treatment, corticotherapy, antibiotic therapy (in the absence of the identified etiology, initially meropenem was administered in association with linezolid, and then ceftazidime-avibactam), voriconazole, anakinra, salbutamol inhaler, inhalation corticosteroids, with slow reduction in oxygen requirement, the patient continued oxygen therapy at home after discharge with a flow rate of 5 L/minute. During the third harvesting of sputum samples, P. putida was isolated along with L. amnigena, both strains of low-virulence species, and maintained susceptibility to antibiotics. In the context of an immunosuppressed patient with previous pulmonary surgery for actinomycosis, chronic obstructive pulmonary disease, and bronchiectasis, all these conditions are favorable for biofilm formation. L. amnigena remains a pathogen rarely isolated in human pathology, but we should pay more attention, especially in the immunosuppressed patient, where it can be responsible for an extremely serious clinical picture.