Accurate identification and virulence detection of Aeromonas: a single-center retrospective study of clinical features and outcomes of Aeromonas bacteremia in southwestern China

Abstract

Aeromonas was re-identified in the work, and the clinical aspects of Aeromonas bacteremia were clarified, additionally drug resistance and virulence genes connected to Aeromonas. By using the housekeeping genes, 188 Aeromonas strains were identified into 7 species, which was a standard to assess the accuracy of the VITEK MALDI-TOF system and the VITEK2 compact system. VITEK MS system and housekeeping genes had a 39.89% clear coincidence rate, while Vitek2 Compact system and the standard had a 2.13%. Aeromonas bacteremia was associated with septic shock, hematologic malignancy, and posthepatitic cirrhosis. Hematologic malignancy, hypoproteinemia, systemic steroid use, central venous catheterization and act and ast gene were all linked to poor outcomes. Aeromonas bacteremia had a 37.5% mortality, but there were differences in mortality among Aeromonas species. According to the broth microdilution method, except for ceftriaxone (83.33%) and imipenem (83.33%), over 90% of isolates were sensitive to the most antimicrobials. Touch-down polymerase chain reaction (PCR) assays and DNA sequencing verified the presence of drug resistance genes, and bla_CphA was found in three isolates, and bla_NDM-1 in one. In short, common methods for identifying Aeromonas species were ineffective. Immunocompromised patients had a higher risk of infections and mortality. Carbapenem resistance was a serious issue.