Carbapenem-resistant Klebsiella pneumoniae is associated with poor outcome in hemodialysis patients

The lived experience of haemodialysis patients managed with transmission-based precautions for MDRO colonisation: A qualitative study

BACKGROUND

Patients undergoing haemodialysis colonised with multi-drug resistant organisms (MDROs) are commonly managed with transmission-based precautions (TBP) to prevent nosocomial transmission. TBP have been linked to mixed effects on patient psychological well-being and clinical care. This study was designed to report the lived experience of dialysis patients managed with TBP.

METHODS

A qualitative study of 15 patients undergoing haemodialysis managed with TBP was performed. Participants took part in individual semi-structured interviews. Data was analysed utilising an interpretive phenomenological approach.

RESULTS

Four themes were identified. 1. Communication of what MDRO screening meant, the results, and implications of MDRO positivity was perceived by many patients as insufficient and inconsistent. 2. Experiences of care in isolation were described, with both positive (privacy) and negative (reduced interaction) experiences identified. 3. Psychosocial and emotional responses including concern about health implications and stigma were reported, but also screening was described by some as increasing their perception of being cared for by health care workers, as they felt all health risks were being managed. 4. Confusion around perceived inconsistencies of management, particularly across different environments (eg hospital vs home) and staff.

CONCLUSION

TBP have complex positive and negative impacts on patients which should be considered when developing MDRO management policy and communication around such policy. Strategies to improve communication, patient and staff education, and remove (or explain) perceived inconsistencies of practice may reduce the negative consequences of TBP leading to improved delivery of quality, person-centred care.

Comparison of Four Carbapenemase Detection Methods for blaKPC-2 Variants

Recently, various bla_KPC-2 variants resistant to ceftazidime-avibactam have begun to emerge in clinical settings, but it is unclear which testing method is most appropriate for detecting these variants. Strains were subjected to antimicrobial susceptibility testing using the broth microdilution method. Four carbapenemase detection methods, modified carbapenem inactivation method (mCIM) and EDTA carbapenem inactivation method (eCIM), APB/EDTA (carbapenemase inhibitor APB [3-aminophenylboronic acid] and EDTA enhancement method), NG-test Carba 5, and GeneXpert Carba-R were used to try to detect KPC-2 variants in 19 Klebsiella pneumoniae isolates. Among those bla_KPC-2 variants, bla_KPC-33-, bla_KPC-35-, bla_KPC-71-, bla_KPC-76-, bla_KPC-78-, and bla_KPC-79-positive isolates accounted for 26.3% (5/19), 15.8% (3/19), 5.3% (1/19), % 42.1% (8/19), 5.3% (1/19), and 5.3% (1/19), respectively. All 19 K. pneumoniae carrying bla_KPC-2 variants showed resistance to ceftazidime-avibactam (MICs:16 to >64 mg/L), and 14 strains were susceptible to imipenem (MICs: 0.25 to 1 mg/L). None of the bla_KPC-2 variants could be detected using either the mCIM or the APB/EDTA method, while five strains carrying bla_KPC-2 variants (bla_KPC-35, bla_KPC-78, and bla_KPC-79) tested KPC positive when using NG-test Carba 5. However, GeneXpert Carba-R was able to detect bla_KPC-2 variants (harboring bla_KPC-33, bla_KPC-35, bla_KPC-71, bla_KPC-76, bla_KPC-78, and bla_KPC-79) carried by all 19 K. pneumoniae. The emergence of new KPC variants poses an increased challenge for carbapenemase detection methods, and laboratories should use the appropriate assays to accurately detect these variants.

IMPORTANCE Carbapenemase detection is essential for the appropriate treatment of CRE infections. Several clinical laboratories have begun using relevant carbapenemase assays such as mCIM and eCIM, the APB/EDTA method, NG-test Carba 5, and GeneXpert Carba-R to detect carbapenemases. Nevertheless, some of these methods may have limitations for detecting bla_KPC-2 variants. Additionally, there has been little relevant research on evaluate the differences between these standard methods for detecting bla_KPC-2 variants. Therefore, we investigated the reliability of these classic methods for assessing 19 K. pneumoniae with bla_KPC-2 variants. Our results showed that none of the bla_KPC-2 variants could be detected using either the mCIM or APB/EDTA method, while five strains (harboring bla_KPC-35, bla_KPC-78,and bla_KPC-79) tested KPC positive when using NG-test Carba 5. GeneXpert Carba-R could detect six bla_KPC-2 variants carried by all 19 K. pneumoniae. This study may be valuable for clinical laboratories in their efforts to test for various bla_KPC-2 variants.

Coupling Machine Learning and High Throughput Multiplex Digital PCR Enables Accurate Detection of Carbapenem-Resistant Genes in Clinical Isolates

Rapid and accurate identification of patients colonised with carbapenemase-producing organisms (CPOs) is essential to adopt prompt prevention measures to reduce the risk of transmission. Recent studies have demonstrated the ability to combine machine learning (ML) algorithms with real-time digital PCR (dPCR) instruments to increase classification accuracy of multiplex PCR assays when using synthetic DNA templates. We sought to determine if this novel methodology could be applied to improve identification of the five major carbapenem-resistant genes in clinical CPO-isolates, which would represent a leap forward in the use of PCR-based data-driven diagnostics for clinical applications. We collected 253 clinical isolates (including 221 CPO-positive samples) and developed a novel 5-plex PCR assay for detection of bla_IMP, bla_KPC, bla_NDM, bla_OXA-48, and bla_VIM. Combining the recently reported ML method “Amplification and Melting Curve Analysis” (AMCA) with the abovementioned multiplex assay, we assessed the performance of the AMCA methodology in detecting these genes. The improved classification accuracy of AMCA relies on the usage of real-time data from a single-fluorescent channel and benefits from the kinetic/thermodynamic information encoded in the thousands of amplification events produced by high throughput real-time dPCR. The 5-plex showed a lower limit of detection of 10 DNA copies per reaction for each primer set and no cross-reactivity with other carbapenemase genes. The AMCA classifier demonstrated excellent predictive performance with 99.6% (CI 97.8–99.9%) accuracy (only one misclassified sample out of the 253, with a total of 160,041 positive amplification events), which represents a 7.9% increase (p-value <0.05) compared to conventional melting curve analysis. This work demonstrates the use of the AMCA method to increase the throughput and performance of state-of-the-art molecular diagnostic platforms, without hardware modifications and additional costs, thus potentially providing substantial clinical utility on screening patients for CPO carriage.

Detection of blaKPC and blaNDM genes by duplex PCR with lateral flow dipsticks from sterile body fluid samples

Duplex polymerase chain reaction with lateral flow dipsticks (duplex PCR-LFD) was developed for the simultaneous detection of beta-lactamase Klebsiella pneumoniae carbapenemase (bla_KPC ) and beta-lactamase New Dehli metallo-beta-lactamase (bla_NDM ) genes in body fluid samples. This method was validated using well-characterized isolates. The assessment of the specificity of duplex PCR-LFD showed that there was no cross-reactivity with other targets. The detection limit of the duplex PCR-LFD assay was 20 CFU per ml for bla_KPC and bla_NDM . Among 177 sterile body fluid samples tested by the duplex PCR-LFD assay, 40 were bla_KPC -positive and five were bla_NDM -positive. The results obtained from 122 corresponding Gram-negative bacteria which were isolated from these clinical samples and tested by duplex PCR-LFD assay showed that there were 37 strains carrying bla_KPC genes in 40 bla_KPC -positive samples and three strains carrying bla_NDM genes in five bla_NDM -positive samples. Statistical analysis indicated that there was no significant difference between the direct detection of bla_KPC and bla_NDM genes in clinical sterile body fluid samples and their corresponding clinical isolates. Therefore, duplex PCR-LFD can be effective for the simultaneous detection of bla_KPC and bla_NDM in clinical isolates and directly from clinical samples, which may be helpful for the administration of appropriate antimicrobial treatment.

Clinical features and development of Sepsis in Klebsiella pneumoniae infected liver abscess patients: a retrospective analysis of 135 cases

Background

Klebsiella pneumoniae is a primary pathogen of pyogenic liver abscess (PLA). However, little data are available on combination with sepsis. In this study, we aimed to evaluate the clinical characteristics and prognostic differences of PLA patients with sepsis.

Methods

This retrospective cohort study was conducted to investigate 135 patients with confirmed Klebsiella pneumoniae-caused liver abscesses (KPLA) from a tertiary teaching hospital, from 2013 to 2019. The patients were divided into two groups, KPLA with sepsis and KPLA without sepsis. The demographic characteristics, clinical features as well as laboratory and microbiologic findings were analyzed.

Results

A total of 135 patients with KPLA were analyzed. The mean age of patients was 60.9 ± 12.7 years, and the percentage of men was 59.3%. Among them, 37/135 (27.4%) of patients had sepsis and the mortality rate was 1.5%. The most common symptom was fever (91.1%). KPLA patients with sepsis had a significantly higher proportion of frailty, diarrhea, fatty liver, chronic renal insufficiency, and hepatic dysfunction compared to KPLA patients without sepsis (p < 0.05). Antibiotic therapy and percutaneous drainage were most frequently therapeutic strategy. Furthermore, the incidences of sepsis shock and acute respiratory distress syndrome were higher in the sepsis group compared to the non-sepsis group. As for metastatic infections, the lung was the most common site. In addition, KPLA patients with sepsis showed respiratory symptoms in 11 patients, endophthalmitis in 4 patients, and meningitis in 1 patient.

Conclusion

Our findings emphasize that KPLA patients combined with or without sepsis have different clinical features, but KPLA patients with sepsis have higher rates of complications and metastatic infections. Taken together, further surveillance and control of septic spread is essential for KPLA patients.

Risk factors for carbapenemase-producing organisms among inpatients in Scotland: A national matched case–control study

Objective:

To determine risk factors for carbapenemase-producing organisms (CPOs) and to determine the prognostic impact of CPOs.

Design:

A retrospective matched case–control study.

Patients:

Inpatients across Scotland in 2010–2016 were included. Patients with a CPO were matched with 2 control groups by hospital, admission date, specimen type, and bacteria. One group comprised patients either infected or colonized with a non-CPO and the other group were general inpatients.

Methods:

Conditional logistic regression models were used to identify risk factors for CPO infection and colonization, respectively. Mortality rates and length of postisolation hospitalization were compared between CPO and non-CPO patients.

Results:

In total, 70 CPO infection cases (with 210 general inpatient controls and 121 non-CPO controls) and 34 CPO colonization cases (with 102 general inpatient controls and 60 non-CPO controls) were identified. Risk factors for CPO infection versus general inpatients were prior hospital stay (adjusted odds ratio [aOR], 4.05; 95% confidence interval [CI], 1.52–10.78; P = .005), longer hospitalization (aOR, 1.07; 95% CI, 1.04–1.10; P < .001), longer intensive care unit (ICU) stay (aOR, 1.41; 95% CI, 1.01–1.98; P = .045), and immunodeficiency (aOR, 3.68; 95% CI, 1.16–11.66; P = .027). Risk factors for CPO colonization were prior high-dependency unit (HDU) stay (aOR, 11.46; 95% CI, 1.27–103.09; P = .030) and endocrine, nutritional, and metabolic (ENM) diseases (aOR, 3.41; 95% CI, 1.02–11.33; P = .046). Risk factors for CPO infection versus non-CPO infection were prolonged hospitalization (aOR, 1.02; 95% CI, 1.00–1.03; P = .038) and HDU stay (aOR, 1.13; 95% CI, 1.02–1.26; P = .024). No differences in mortality rates were detected between CPO and non-CPO patients. CPO infection was associated with longer hospital stay than non-CPO infection (P = .041).

Conclusions:

A history of (prolonged) hospitalization, prolonged ICU or HDU stay; ENM diseases; and being immunocompromised increased risk for CPO. CPO infection was not associated with increased mortality but was associated with prolonged hospital stay.

Five-year change of prevalence and risk factors for infection and mortality of carbapenem-resistant Klebsiella pneumoniae bloodstream infection in a tertiary hospital in North China

BACKGROUND

There are few studies focused on carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection (BSI). The aim of this study is to identify the prevalence and risk factors for infection and mortality of CRKP BSI.

METHODS

Susceptibility of Klebsiella pneumoniae (KP) isolated from blood samples and the proportion of CRKP were recorded annually. One hundred sixty-four patients with CRKP and 328 with carbapenem-susceptible Klebsiella pneumoniae (CSKP) BSI were categorized as the case group and control group to identify risk factors for CRKP infection and mortality by univariable analysis and multivariable logistic-regression analysis.

RESULTS

The proportion and mortality of CRKP BSI increased significantly, with the percentage of KP in BSI increasing from 7 to 12% from 2014 to 2019 with a concomitant resistance to meropenem increasing from 16.7 to 41.8%. Compared with CSKP group, patients in CRKP group had longer hospitalization time before bacteremia (median 14 vs 4, P < 0.001) and longer total hospitalization time (median 31 vs 19, P < 0.001). The proportion of admission to ICU was higher (70.7% vs 17.7%, P < 0.001), and APACHE II score was higher (median 12 vs 8, P < 0.001). The mortality in CRKP group was 43.9% (72/164), while 14.9% (49/328) in CSKP group (p < 0.001). KP detection in other sites(P = 0.036, OR 1.964), blood purification(P = 0.018, OR 3.326), bronchoscopy(P = 0.011, OR 5.423), surgery (P = 0.001, OR 3.084), carbapenem use(P = 0.001, OR 3.395), tigecycline use(P = 0.006, OR 4.595) were independent risk factors for CRKP BSI. Previous hospitalization (P = 0.048, OR 2.755), long hospitalization (P = 0.003, OR 1.035), bone marrow puncture (P = 0.037, OR3.856), use of β-lactamase inhibitor (P = 0.005, OR 3.890) were independent risk factors for mortality in CRKP BSI.

CONCLUSION

The prevalence and mortality of CRKP BSI are still increasing. Timely treatment of KP infection in other site, strengthening the hospital infection control of blood purification, bronchoscopy and surgery, control the use of carbapenem and tigecycline, may help to prevent CRKP BSI. More preventative hospital resources are needed for severely ill patients with prolonged hospitalizations and intensive care.

A New Delhi metallo-β-lactamase (NDM)-positive isolate of Klebsiella pneumoniae causing catheter-related bloodstream infection in an ambulatory hemodialysis patient

The New Delhi metallo-β-lactamase (NDM) is a mediator of broad antimicrobial resistance among the Enterobacteriaceae and other gram-negative pathogens that cause opportunistic and nosocomial infections. In the decade since its discovery, NDM has spread worldwide and represents an increasing threat to public health. NDM is capable of hydrolyzing nearly all known β-lactam antibiotics, including the carbapenems, and due to its zinc ion-dependent catalytic mechanism is unaffected by available β-lactamase inhibitors. We report a case of catheter-related bloodstream infection caused by a pan-resistant, NDM-positive isolate of Klebsiella pneumoniae in an ambulatory end-stage renal disease patient started on hemodialysis approximately 8 weeks prior. The absence of any recent hospitalization indicates that the infection was likely acquired from a hemodialysis center in the United States. This case demonstrates the increasing prevalence of antimicrobial resistance mechanisms in ambulatory as well as inpatient healthcare settings, and highlights the particular risk of the outpatient hemodialysis facility as an optimal environment for colonization with multidrug- and pandrug-resistant pathogens.

Association between carbapenem-resistant Enterobacteriaceae and death: A systematic review and meta-analysis

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) has emerged in health care facilities around the world. Several studies demonstrated data regarding clinical outcomes for CRE infections including death. This systematic review and meta-analysis summarized literature discussing association between CRE and mortality.

METHODS

A systematic literature review was performed by searching EMBASE, International Pharmaceutical Abstract databases, PubMed, and Scopus and to identify studies that assessed the association between CRE and death published from April 2012 to October 2017. A meta-analysis was performed using a random effect model. Heterogeneity was assessed using the I²-statistic.

RESULTS

Twenty-one studies were included in this meta-analysis. The underlying populations were moderately heterogeneous (I² = 60%; P = .01). Pooled risk estimates from 9 studies revealed a significant association between CRE and death (pooled-adjusted odds ratio: 2.85; 95% confidence interval: 1.88, 4.30). The unadjusted variable pooled from 18 studies demonstrated a significant association between CRE and death (pooled-unadjusted odds ratio: 3.73; 95% confidence interval: 2.02, 6.88).

DISCUSSION

The finding that CRE infection was positively associated with death agreed with the previous meta-analysis of studies published before April 2012.

CONCLUSIONS

This meta-analysis found that CRE was associated with increased risk of death. Our analysis implies a need for strict infection control measures.

Association Between Carbapenem Resistance and Mortality Among Adult, Hospitalized Patients With Serious Infections Due to Enterobacteriaceae: Results of a Systematic Literature Review and Meta-analysis

This study quantified mortality associated with serious infections caused by carbapenem-resistant (CRE) and carbapenem-susceptible Enterobacteriaceae (CSE). A systematic literature review was conducted, evaluating outcomes in hospitalized patients with CRE infections from a blood, urinary, pulmonary, or intra-abdominal source. A meta-analysis (MA) calculating odds ratios (ORs) for mortality was performed. Twenty-two studies met the criteria for inclusion in the MA: 12 included mortality data for CRE vs CSE populations. Compared with CSE, CRE was associated with a significantly higher risk of overall mortality (OR, 3.39; 95% confidence interval [CI], 2.35-4.89), as was monotherapy (vs combination therapy) treatment of patients with CRE infections (OR, 2.19; 95% CI, 1.00-4.80). These results document the increased mortality associated with serious CRE infections compared with CSE infections among hospitalized adults. It will be important to reevaluate the mortality in CRE and CSE populations, especially among patients who receive early appropriate therapy, as new antibiotics become available.

A Systematic Review and Meta-analyses of the Clinical Epidemiology of Carbapenem-Resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are major health care-associated pathogens and responsible for hospital outbreaks worldwide. To prevent a further increase in CRE infections and to improve infection prevention strategies, it is important to summarize the current knowledge about CRE infection prevention in hospital settings. This systematic review aimed to identify risk factors for CRE acquisition among hospitalized patients. In addition, we summarized the environmental sources/reservoirs and the most successful infection prevention strategies related to CRE. A total of 3,983 potentially relevant articles were identified and screened. Finally, we included 162 studies in the systematic review, of which 69 studies regarding risk factors for CRE acquisition were included in the random-effects meta-analysis studies. The meta-analyses regarding risk factors for CRE acquisition showed that the use of medical devices generated the highest pooled estimate (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 3.38 to 7.67), followed by carbapenem use (OR = 4.71; 95% CI = 3.54 to 6.26). To control hospital outbreaks, bundled interventions, including the use of barrier/contact precautions for patients colonized or infected with CRE, are needed. In addition, it is necessary to optimize the therapeutic approach, which is an important message to infectious disease specialists, who need to be actively involved in a timely manner in the treatment of patients with known CRE infections or suspected carriers of CRE.

Carbapenem-Resistant Enterobacteriaceae Infections in Patients on Renal Replacement Therapy

BACKGROUND

Patients on chronic intermittent renal replacement therapy (RRT) are at risk for infection with carbapenem-resistant Enterobacteriaceae (CRE). However, the impact of RRT on outcomes after CRE infections remains to be defined. Here we perform a comparison of outcomes for CRE-infected patients with preserved renal function compared with CRE-infected patients on RRT.

METHODS

Cases and controls were defined from a prospective cohort of CRE-infected patients from the Consortium on Resistance against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE). Cases were defined as CRE-infected patients on RRT at hospital admission, while controls were defined as CRE-infected patients with serum creatinine <2 mg/dL and not receiving RRT at admission. Risk factors for 28-day in-hospital mortality were assessed using multivariable logistic regression. An ordinal ranking of outcomes by desirability analysis was performed.

RESULTS

Patients on RRT were more likely to have diabetes mellitus and cardiac disease than controls. Urinary sources of infection were less common in the RRT group. In RRT patients, 28-day in-hospital mortality was increased as compared with controls: 22/71 (31%) vs 33/295 (11%). RRT remained significantly associated with 28-day in-hospital mortality after adjustment for source of infection, prehospitalization origin, and severity of illness (adjusted odds ratio, 2.27; 95% confidence interval [CI], 1.09-4.68; P = .03). Using univariable desirability of outcome ranking analysis, RRT status was associated with a 68% (95% CI, 61%-74%) chance of a worse disposition outcome.

CONCLUSIONS

Chronic RRT in CRE-infected patients is associated with increased in-hospital mortality and worse disposition outcomes at 28 days.

Developing New Antimicrobial Therapies: Are Synergistic Combinations of Plant Extracts/Compounds with Conventional Antibiotics the Solution?

The discovery of penicillin nearly 90 years ago revolutionized the treatment of bacterial disease. Since that time, numerous other antibiotics have been discovered from bacteria and fungi, or developed by chemical synthesis and have become effective chemotherapeutic options. However, the misuse of antibiotics has lessened the efficacy of many commonly used antibiotics. The emergence of resistant strains of bacteria has seriously limited our ability to treat bacterial illness, and new antibiotics are desperately needed. Since the discovery of penicillin, most antibiotic development has focused on the discovery of new antibiotics derived from microbial sources, or on the synthesis of new compounds using existing antibiotic scaffolds to the detriment of other lines of discovery. Both of these methods have been fruitful. However, for a number of reasons discussed in this review, these strategies are unlikely to provide the same wealth of new antibiotics in the future. Indeed, the number of newly developed antibiotics has decreased dramatically in recent years. Instead, a reexamination of traditional medicines has become more common and has already provided several new antibiotics. Traditional medicine plants are likely to provide further new antibiotics in the future. However, the use of plant extracts or pure natural compounds in combination with conventional antibiotics may hold greater promise for rapidly providing affordable treatment options. Indeed, some combinational antibiotic therapies are already clinically available. This study reviews the recent literature on combinational antibiotic therapies to highlight their potential and to guide future research in this field.

Carbapenemase-producing Enterobacteriaceae: Risk factors for infection and impact of resistance on outcomes

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) have increased in recent years leading to limitations of treatment options. The present study was undertaken to detect CPE, risk factors for acquiring them and their impact on clinical outcomes.

METHODS

This retrospective observational study included 111 clinically significant Enterobacteriaceae resistant to cephalosporins subclass III and exhibiting a positive modified Hodge test. Screening for carbapenemase production was done by phenotypic methods, and polymerase chain reaction was performed to detect genes encoding them. Retrospectively, the medical records of the patients were perused to assess risk factors for infections with CPE and their impact. The data collected were duration of hospital stay, Intensive Care Unit (ICU) stay, use of invasive devices, mechanical ventilation, the presence of comorbidities, and antimicrobial therapy. The outcome was followed up. Univariate and multivariate analysis of the data were performed using SPSS software.

RESULTS

Carbapenemase-encoding genes were detected in 67 isolates. The genes detected were New Delhi metallo-β-lactamase, Verona integron-encoded metallo-β-lactamase, and oxacillinase-181.Although univariate analysis identified risk factors associated with acquiring CPE infections as ICU stay (P = 0.021), mechanical ventilation (P = 0.013), indwelling device (P = 0.011), diabetes mellitus (P = 0.036), usage of multiple antimicrobial agents (P = 0.007), administration of carbapenems (P = 0.042), presence of focal infection or sepsis (P = 0.013), and surgical interventions (P = 0.016), multivariate analysis revealed that all these factors were insignificant. Mortality rate was 56.7% in patients with CPE infections. By both univariate and multivariate analysis of impact of the variables on mortality in these patients, the significant factors were mechanical ventilation (odds ratio [OR]: 0.141, 95% confidence interval [CI]: 0.024-0.812) and presence of indwelling invasive device (OR: 8.034; 95% CI: 2.060-31.335).

CONCLUSION

In this study, no specific factor was identified as an independent risk for acquisition of CPE infection. However, as it is evident by multivariate analysis, there is an increased risk of mortality in patients with CPE infections when they are ventilated and are supported by indwelling devices.

Characteristics, risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in the intensive care unit

OBJECTIVE

To study the characteristics, risk factors and outcomes of intensive care unit (ICU) patients with carbapenem-resistant (CRKp) and carbapenem-susceptible (CSKp) Klebsiella pneumoniae infections.

METHODS

A retrospective cohort of patients with K. pneumoniae infections in an eight-bed ICU between January 2006 and October 2009.

RESULTS

During the study period, 104 patients were diagnosed with K. pneumoniae infection (80 CRKp and 24 CSKp). Isolation of CRKp increased gradually during the study period, while isolation of CSKp remained constant. The mean age of patients was 66.3 ± 14.3 years. The mean APACHE II score was 17.9 ± 6.9. The median duration of ICU stay until the infection was 15 days. Thirty five patients (33.7%) had primary and 30 (28.8%) had secondary bacteremia. Seventy-two patients (69.2%) died in the ICU. No independent risk factors for development of CRKp infections were identified in the multivariate analysis. Treatment failure (p = 0.001) was the only independent predictor of mortality in the multivariate analysis (APACHE II, shock, multi-organ failure, respiratory failure, acute renal failure, acidosis and extensive-drug resistance were included in the model). No difference in mortality was found between patients with CRKp and CSKp isolates.

CONCLUSIONS

Infection due to K. pneumoniae in the ICU was associated with high mortality. Control of the infection was the most important determinant of the outcome of critically ill patients.

Carbapenem-resistant Enterobacteriaceae: biology, epidemiology, and management

Introduced in the 1980s, carbapenem antibiotics have served as the last line of defense against multidrug-resistant Gram-negative organisms. Over the last decade, carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a significant public health threat. This review summarizes the molecular genetics, natural history, and epidemiology of CRE and discusses approaches to prevention and treatment.