Surveillance of Carbapenem-Resistant Klebsiella pneumoniae: Tracking Molecular Epidemiology and Outcomes through a Regional Network

Abstract

m Carbapenem resistance in Gram-negative bacteria is on the rise in the United States. A regional network was established to study microbiological and genetic determinants of clinical outcomes in hospitalized patients with carbapenem-resistant (CR) Klebsiella pneumoniae in a prospective, multicenter, observational study. To this end, predefined clinical characteristics and outcomes were recorded and K. pneumoniae isolates were analyzed for strain typing and resistance mechanism determination. In a 14-month period, 251 patients were included. While most of the patients were admitted from long-term care settings, 28% of them were admitted from home. Hospitalizations were prolonged and complicated. Nonsusceptibility to colistin and tigecycline occurred in isolates from 7 and 45% of the patients, respectively. Most of the CR K. pneumoniae isolates belonged to repetitive extragenic palindromic PCR (rep-PCR) types A and B (both sequence type 258) and carried either bla KPC-2 (48%) or bla KPC-3 (51%). One isolate tested positive for bla NDM-1 , a sentinel discovery in this region. Important differences between strain types were noted; rep-PCR type B strains were associated with bla KPC-3 (odds ratio [OR], 294; 95% confidence interval [CI], 58 to 2,552; P < 0.001), gentamicin nonsusceptibility (OR, 24; 95% CI, 8.39 to 79.38; P < 0.001), amikacin susceptibility (OR, 11.0; 95% CI, 3.21 to 42.42; P < 0.001), tigecycline nonsusceptibility (OR, 5.34; 95% CI, 1.30 to 36.41; P ‫؍‬ 0.018), a shorter length of stay (OR, 0.98; 95% CI, 0.95 to 1.00; P ‫؍‬ 0.043), and admission from a skilled-nursing facility (OR, 3.09; 95% CI, 1.26 to 8.08; P ‫؍‬ 0.013). Our analysis shows that (i) CR K. pneumoniae is seen primarily in the elderly long-term care population and that (ii) regional monitoring of CR K. pneumoniae reveals insights into molecular characteristics. This work highlights the crucial role of ongoing surveillance of carbapenem resistance determinants.

A Two-Year Surveillance in Five Colombian Tertiary Care Hospitals Reveals High Frequency of Non-CG258 Clones of Carbapenem-Resistant Klebsiella pneumoniae with Distinct Clinical Characteristics

“…For example, our findings are consistent with the observations in previous studies that described most patients to be elderly, with multiple comorbidities (2,57,61) and with UTI and bloodstream infections the most frequently reported (42,57,(61)(62)(63). Several studies evaluating risk factors for CR-Kp acquisition found exposure to health care and previous antimicrobial use as the most significant risks (3,9,(61)(62)(63)(64)(65)(66)(67)(68)(69).…”

“…This is consistent with our findings that medical history showing surgery, hospitalization, antibiotic use prior to infection, and the presence of invasive medical devices at the moment of infection were associated with CR-Kp acquisition (Table 1). Meanwhile, we found an overall 34% mortality rate, in accordance with previous reports of rates that varied from 6% to 60% depending on the severity of infection (9,42,(68)(69)(70). Interestingly, our study revealed a highly heterogeneous genetic background of CR-Kp strains, and CR-Kp from different clones displayed distinct clinical characteristics in our local epidemiology.…”

“…Of clinical importance, isolates resistant to both tigecycline and colistin or colistin alone were predominantly found in this clone. Similar events have been described in countries where CG258 is highly prevalent (35)(36)(37)(38)(39)(40)(41)(42), and in these areas where KPC-Kp is highly endemic and colistin exposure is high, resistance has been reported (38). This raises a significant concern given the fact that colistin is among the few agents that retain activity against CR-Kp and is the key component of the combination antimicrobial regimens that are frequently administered (2,5,36,43,44).…”

Multidrug-Resistant Gram-Negative Pneumonia and Infection in Intensive Care Unit

“…These patients also frequently have multiple comorbidities, poor functional status, recent intravenous antibiotic exposure (within 90 days), and indwelling devices (urinary catheter, mechanical ventilation, indwelling lines). Patients that recover from their acute hospitalization are frequently discharged to LTCFs or LTACHs, thus contributing to a viscous cycle [10,12]. LTACHs play an important role in the regional epidemiology of CRE.…”

“…coli expressing CTX-M-type enzymes containing ESBLs have been increasingly seen in the community [12,[22][23][24][25][26]. Residency of a long-term care facility has been recognized as a prominent risk factor for acquisition of ESBL infections in the community.…”