Hematogenous pulmonary abscess and septicemia due to infection with hypervirulent Pseudomonas aeruginosa in a nonimmunodeficient adolescent: a case report

Pseudomonas aeruginosa is a non-glucose-fermenting gram-negative bacillus and an opportunistic pathogen that typically causes localized or systemic infections in immunocompromised middle-aged and elderly individuals or children with congenital immune deficiencies. However, cases of pulmonary abscess with severe sepsis in normal individuals are rare and should be taken seriously. A 15-year-old nonimmunodeficient adolescent was hospitalized due to high fever and other clinical symptoms. The patient was diagnosed with a pulmonary abscess with severe sepsis. Etiological Examination showed that sensitive Pseudomonas aeruginosa. Subsequent inspection revealed this clinical isolate produces virulence factors ExoA and Pyocyanin, which was highly virulent. The patient’s symptoms were improved after imipenem (IPM) treatment and discharged. At follow-up 3 months later, he had recovered well. We report a case of a pulmonary abscess with severe sepsis caused by Pseudomonas aeruginosa in an immunocompetent patient. Compared with the vast majority of infections caused by P. aeruginosa, this patient was younger and had no immunodeficiency or basic diseases, and the characteristics of the lesions were also unique. For this P. aeruginosa isolate, the testings of antimicrobial drugs were generally sensitive, and the virulence factors ExoA and Pyocyanin by quantitative metagenomics next-generation sequencing may be the main factors for the severity.