De novo daptomycin non-susceptible enterococci causing urinary tract infection: A study from north India

Daptomycin is a bactericidal agent active against vancomycin resistant enterococci (VRE) which are emergent nosocomial uropathogens. There is limited data available on daptomycin non-susceptible enterococci (DNSE) in India. Herein we describe the emergence of de novo DNSE causing urinary tract infections (UTI) from India

We prospectively screened, consecutive enterococci (n=140) grown in significant numbers (≥10⁵cfu/ml) from urine cultures in hospitalized patients (n=12434) over 6 months. Isolates with daptomycin minimum inhibitory concentration (MIC) >4μg/ml by E-test and no history of daptomycin exposure were defined as DNSE. Colonization and symptomatic UTI was defined as per the Centre for Disease Control and Prevention guidelines

Prevalence of DNSE was 12.1% (17/140) and all were E. faecium. In 6 cases (35.2%) DNSE isolates were colonizers while 11(64.71%) were from UTI cases. Urosepsis occurred in 4 cases, of which 3 died. History of immunocompromise, recent urogenital surgery and indwelling per-urethral catheter were present in 47%, 58.8% and 64.7% cases respectively. Exposure to third generation cephalosporin and metronidazole was seen in nine (52.9%) and 3 (17.65%) cases respectively, while one patient each had vancomycin and teicoplanin exposure. Daptomycin MIC range was 6 to >256 μg/ml. Resistance to ciproflocaxin, amoxicillin, high level gentamicin, tetracycline, nitrofurantoin and vancomycin was seen in 100%, 94.1%, 88.2%, 52.9%, 41.1% and 23.5% respectively. All DNSE were susceptible to linezolid

A high prevalence of DNSE warrants further case control studies, molecular and epidemiological studies to elucidate the risk factors, molecular mechanisms of resistance and epidemiological origin of these isolates.