Clinical Profile, Comorbidities, and Antimicrobial Resistance Patterns of Myroides Species Isolated From Nosocomial Urinary Tract Infections at a Tertiary Care Center in India: A Retrospective Observational Study

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Background Myroides species are gram-negative, aerobic bacilli within the family Flavobacteriaceae that have emerged as clinically significant, multidrug-resistant nosocomial pathogens. Although historically regarded as organisms of low pathogenicity, they are increasingly associated with opportunistic infections, particularly urinary tract infections (UTIs), among hospitalized, immunocompromised, and catheterized patients. Reports of Myroides infections have increased in recent years across different geographical regions, highlighting its emerging global clinical significance. The incidence of reported Myroides infections has increased steadily over the last two decades and is recognized as an opportunistic pathogen associated with multidrug resistance. Limited information is available on their clinical characteristics and antimicrobial susceptibility patterns from the Indian subcontinent. Hence, this study aimed to characterize the demographic, clinical features, and antimicrobial resistance patterns of Myroides isolates recovered from nosocomial UTIs. Methodology This retrospective observational study was conducted over a 6.5-year period (January 2019-July 2025). All consecutive urine culture isolates producing Myroides spp. at significant colony counts (≥105 CFU/mL) were included. Isolate identification and antimicrobial susceptibility testing (AST) were performed using VITEK® 2 Compact 60 (bioMérieux, France) or MicroScan WalkAway Model DxM 1096 (Beckman Coulter, Inc., United States). Demographic data, clinical characteristics, risk factors, and antimicrobial susceptibility patterns were examined. Results A total of 53 Myroides isolates were identified. The median age of the patients was 43.5 years (interquartile range = 30-57), with a predominance of males (33, 62.3%). The majority of the cases were from Urology (17, 32.1%) and General Medicine (11, 20.8%) departments. Device in situ (46, 86.8%) and immunocompromised state (20, 37.7%) were the most common predisposing factors. Mortality was observed in (13, 24.5%) patients, with non-survivors more commonly being male and immunocompromised. Minocycline was the only antibiotic that showed (38/38, 100%) susceptibility. All isolates showed resistance to aminoglycosides (amikacin, gentamicin), fluoroquinolones (ciprofloxacin, levofloxacin), and the majority of the β-lactams tested. Trimethoprim-sulfamethoxazole was susceptible in only 8 (15.1%) isolates. Conclusions Myroides spp. is a significant but frequently overlooked nosocomial threat, characterized by extensive multidrug resistance and often isolated in high-dependency inpatient settings. Minocycline consistently retains antimicrobial activity against Myroides spp. Accurate species identification and systematic AST reporting are important for appropriate clinical management.