Identification of Extended-Spectrum-β-Lactamase-Positive Klebsiella pneumoniae Urinary Tract Isolates Harboring KPC and CTX-M β-Lactamases in Nonhospitalized Patients

Abstract

dForty-seven extended-spectrum-␤-lactamase-positive Klebsiella pneumoniae urinary tract isolates from nonhospitalized patients were identified, and 79% harbored KPC and/or CTX-M ␤-lactamases. Approximately 90% of the isolates were resistant to trimethoprim-sulfamethoxazole and levofloxacin, and 40% were resistant to a carbapenem, while 92% were susceptible to polymyxin B, 87% were susceptible to tigecycline, and 79% were susceptible to fosfomycin. Increased use of broader-spectrum antibiotics may help to prevent their dissemination and reduce the risk of progression to invasive disease. The isolation of multidrug-resistant Gram-negative bacteria (MDRGNB) from the urinary tract has been documented in a variety of settings (1-8). While recent investigations have identified CTX-M extended-spectrum ␤-lactamases (ESBLs) in Escherichia coli, the carbapenems have remained active against such isolates (4,8,9). Although coexistent Klebsiella pneumoniae carbapenemases (KPC) and CTX-M ESBLs in E. coli urinary tract isolates from patients in long-term-care facilities (LTCFs) have been documented, few studies have been conducted to determine the extent of these enzymes in K. pneumoniae urinary tract isolates from nonhospitalized patients (3, 9). This study was performed to investigate the presence of such enzymes and describe epidemiology, clinical characteristics, and outcomes.From 1 January 2009 through 31 December 2009, 159 single patient urinary tract isolates reported as ESBL positive by the clinical microbiology laboratory using BD Phoenix NMIC/ID-123 panels (Becton Dickinson & Co., Sparks, MD) were identified. Forty-seven of the patients met the definition of "nonhospitalized" (a patient with no history of antibiotic use or hospitalization within the 30 days previous to the time when the urine specimen was obtained). Although there are many definitions of nonhospitalized patients available in the literature, gut flora can be altered after as little as 7 to 10 days into antimicrobial therapy and MDRGN can persist for up to 6 months after the completion of therapy (10, 11). Patients from LTCFs, group homes, or rehabilitation centers were excluded from the study. Specimens were collected from patients during clinic or emergency room visits. Antibiograms of isolates and patients' demographics, including age, gender, comorbid conditions, treatment, and clinical outcomes, were recorded. Readmission data were recoverable only for New York Hospital Queens (NYHQ). This study was conducted at NYHQ as a quality improvement project and did not require Institutional Review Board approval.Additional susceptibility studies were performed in the Infectious Diseases Research Laboratory using Etest methodology according to the manufacturer's specifications (AB Biodisk, Piscataway, NJ) and were interpreted according to Clinical and Laboratory Standards Institute (CLSI)-specified criteria (12). Isolates were also tested for the presence of metallo-␤-lactamases with MBL Etest strips containing imipenem with and without EDTA. The PCR metho...

Epidemiology of β-Lactamase-Producing Pathogens

“…In the early 2000s, K. pneumoniae expressing KPC-2 became endemic across New York City, including in this hospital (221). In a 2009 study, K. pneumoniae isolates coproducing both KPC and CTX-M enzymes were isolated from nonhospitalized patients with urinary tract infections who presented at the emergency room or associated clinic of this hospital (341). Through massive infection control efforts across the city, the prevalence of KPC-producing K. pneumoniae has declined over the last decade, but the pathogen has not completely disappeared (211,234).…”

Fosfomycin for the Treatment of Resistant Gram‐Negative Bacterial Infections

“…A report from Brazil noted susceptibility in 305 (98.1%) of 311 of KpKPC isolates . Two studies from the United States reported 85% susceptibility in KpKPC using the breakpoint of 64 mg/L extrapolated from E. coli ; this decreased to 79% in ESBL producers and to 57% in urinary isolates . Another U.S. study reported 93% overall susceptibility using the same breakpoint, with a rate of 87% in the tigecycline and/or colistin nonsusceptible isolates .…”

Emergence and Evolution of Multidrug-Resistant Klebsiella pneumoniae with both bla KPC and bla CTX-M Integrated in the Chromosome

“…Emergence and facilitated spread of multidrug-resistant (MDR) K. pneumoniae, such as the ESBL (8-10)-and KPC-producing strains (4,5,11), are often responsible for the failure of antibiotic treatment (1). K. pneumoniae isolates carrying both bla CTX-M and bla KPC were first reported in New York City in 2013 (12). However, the genetic structure of these coexisting ␤-lactamases and mechanism of transmission are unclear.…”