Clinical and Microbiological Characteristics and Antimicrobial Susceptibility Patterns of Multidrug-Resistant...

Patients in intensive care units are at risk of infections caused by multidrug-resistant (MDR) pathogens, including the opportunistic bacterium Myroides spp. This study aimed to describe the clinical and microbiological characteristics of MDR Myroides spp. infections and to report antimicrobial susceptibility patterns and treatment approaches used in clinical practice.

In this retrospective single-center study, 70 patients hospitalized in a tertiary care center in Türkiye between 2017 and 2023 who met criteria for true infection were included, although Myroides spp. was isolated from 509 clinical specimens. Demographic, clinical, and laboratory data were analyzed descriptively. Bacterial identification and antimicrobial susceptibility testing were performed using the VITEK^® 2 GN system on specimens obtained from blood, urine, wound swabs, and invasive procedures.

The isolates demonstrated high levels of resistance to most conventional antibiotics tested. Tigecycline showed the highest in vitro susceptibility rate, with 95.2% of isolates classified as susceptible. Tigecycline was also the most frequently used antimicrobial agent in clinical management, with a mean treatment duration of 10.3 days. The mean patient age was 72.7 years, and tigecycline treatment was administered to 88.5% of the patients. Most infections involved the urinary tract, while one patient developed invasive disease with concurrent bacteremia and pneumonia.

MDR Myroides spp. infections remain rare but clinically relevant in intensive care settings. The high in vitro susceptibility observed for tigecycline and its frequent use in treatment highlight its potential role in the management of these infections. However, further studies with comparative designs are needed to better define optimal therapeutic strategies.