Transmission of Carbapenem-Resistant Klebsiella pneumoniae in US Hospitals.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is the most prevalent carbapenem-resistant Enterobacterales in the United States. We evaluated CRKp clustering in patients in US hospitals. METHODS: From April 2016 to August 2017, 350 patients with clonal group 258 CRKp were enrolled in the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae, a prospective, multicenter, cohort study. A maximum likelihood tree was constructed using RAxML. Static clusters shared ≤21 single-nucleotide polymorphisms (SNP) and a most recent common ancestor. Dynamic clusters incorporated SNP distance, culture timing, and rates of SNP accumulation and transmission using the R program TransCluster. RESULTS: Most patients were admitted from home (n = 150, 43%) or long-term care facilities (n = 115, 33%). Urine (n = 149, 43%) was the most common isolation site. Overall, 55 static and 47 dynamics clusters were identified involving 210 of 350 (60%) and 194 of 350 (55%) patients, respectively. Approximately half of static clusters were identical to dynamic clusters. Static clusters consisted of 33 (60%) intrasystem and 22 (40%) intersystem clusters. Dynamic clusters consisted of 32 (68%) intrasystem and 15 (32%) intersystem clusters and had fewer SNP differences than static clusters (8 vs 9; P = .045; 95% confidence interval [CI]: -4 to 0). Dynamic intersystem clusters contained more patients than dynamic intrasystem clusters (median [interquartile range], 4 [2, 7] vs 2 [2, 2]; P = .007; 95% CI: -3 to 0). CONCLUSIONS: Widespread intrasystem and intersystem transmission of CRKp was identified in hospitalized US patients. Use of different methods for assessing genetic similarity resulted in only minor differences in interpretation.

A Systems-Based Analysis of Mono- and Combination Therapy for Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections.

Antimicrobial resistance is a global threat. As "proof-of-concept," we employed a system-based approach to identify patient, bacterial, and drug variables contributing to mortality in patients with carbapenem-resistant Klebsiella pneumoniae (CRKp) bloodstream infections exposed to colistin (COL) and ceftazidime-avibactam (CAZ/AVI) as mono- or combination therapies. Patients (n = 49) and CRKp isolates (n = 22) were part of the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE-1), a multicenter, observational, prospective study of patients with carbapenem-resistant Enterobacterales (CRE) conducted between 2011 and 2016. Pharmacodynamic activity of mono- and combination drug concentrations was evaluated over 24 h using in vitro static time-kill assays. Bacterial growth and killing dynamics were estimated with a mechanism-based model. Random Forest was used to rank variables important for predicting 30-day mortality. Isolates exposed to COL+CAZ/AVI had enhanced early bacterial killing compared to CAZ/AVI alone and fewer incidences of regrowth compared to COL and CAZ/AVI. The mean coefficient of determination (R2) for the observed versus predicted bacterial counts was 0.86 (range: 0.75 - 0.95). Bacterial subpopulation susceptibilities and drug mechanistic synergy were essential to describe bacterial killing and growth dynamics. The combination of clinical (hypotension), bacterial (IncR plasmid, aadA2, and sul3) and drug (KC50) variables were most predictive of 30-day mortality. This proof-of-concept study combined clinical, bacterial, and drug variables in a unified model to evaluate clinical outcomes.

Naïve CD4+ T Cell Lymphopenia and Apoptosis in Chronic Hepatitis C Virus Infection Is Driven by the CD31+ Subset and Is Partially Normalized in Direct-Acting Antiviral Treated Persons.

Background: The mechanisms underlying naïve CD4+ lymphopenia during chronic Hepatitis C Virus (HCV) infection are unclear. Whether direct-acting antiviral (DAA) therapy restores peripheral naïve CD4+ T cell numbers and function is unknown. Methods: We enumerated frequencies and counts of peripheral naïve CD4+, CD4+CD31+ and CD4+CD31- T cells by flow cytometry in a cross sectional analysis comparing chronic HCV infected (n=34), DAA-treated(n=29), and age-range matched controls (n=25), as well as in a longitudinal cohort of HCV DAA treated persons (n=16). The cross-sectional cohort was stratified by cirrhosis state. Cell apoptosis/survival (AnnexinV+7AAD+/BCL-2 labeling) and cell cycle entry (Ki67 expression) of CD31+ and CD31- naïve CD4+ T cells was analyzed directly ex vivo and following 3 and 5 days of in vitro culture with media, interleukin (IL) -7 or CD3/CD28 activator. Results: In the cross-sectional cohort, naïve CD4+ proportions were lower in chronic HCV infected persons compared to controls and DAA-treated persons, an effect in part attributed to cirrhosis. Age was associated with naïve cell counts and proportions in HCV infected and treated persons as well. Naïve CD4+ cell proportions negatively correlated with plasma levels of soluble CD14 following therapy in DAA-treated persons. Naïve CD4+ cells from HCV infected persons exhibited greater direct ex vivo apoptosis and cell-cycling compared to cells from DAA-treated persons and controls, and this was localized to the CD4+CD31+ subset. On the other hand, no remarkable differences in expression of BCL-2 or IL-7 Receptor (CD127) at baseline or following in vitro media or IL7 containing culture were observed. In the longitudinal cohort, naïve CD4+CD31+/CD31- ratio tended to increase 24 weeks after DAA therapy initiation. Conclusions: Activation and apoptosis of peripheral naïve CD4+CD31+ T cells appear to contribute to naïve CD4+ lymphopenia in chronic HCV infection, and this defect is partially reversible with HCV DAA therapy. Age and cirrhosis -associated naïve CD4+ lymphopenia is present both before and after HCV DAA therapy. These findings have implications for restoration of host immune function after DAA therapy.

Plasma Citrate and Succinate Are Associated With Neurocognitive Impairment in Older People With HIV.

BACKGROUND: Neurocognitive impairment (NCI) is associated with monocyte activation in people with HIV (PWH). Activated monocytes increase glycolysis, reduce oxidative phosphorylation, and accumulate citrate and succinate, tricarboxylic acid (TCA) cycle metabolites that promote inflammation-this metabolic shift may contribute to NCI and slowed gait speed in PWH. METHODS: Plasma citrate and succinate were assayed by liquid chromatography-mass spectrometry from 957 participants upon entry to a multicenter, prospective cohort of older PWH. Logistic, linear, and mixed-effects linear regression models were used to examine associations between entry/baseline TCA cycle metabolites and cross-sectional and longitudinal NCI, neuropsychological test scores (NPZ-4), and gait speed. RESULTS: Median age was 51 (range 40-78) years. Each 1 standard deviation (SD) citrate increment was associated with 1.18 higher odds of prevalent NCI at baseline (P = .03), 0.07 SD lower time-updated NPZ-4 score (P = .01), and 0.02 m/s slower time-updated gait speed (P < .0001). Age accentuated these effects. In the oldest age-quartile, higher citrate was associated with 1.64 higher odds of prevalent NCI, 0.17 SD lower NPZ-4, and 0.04 m/s slower gait speed (P ≤ .01 for each). Similar associations were apparent with succinate in the oldest age-quintile, but not with gait speed. In participants without NCI at entry, higher citrate predicted a faster rate of neurocognitive decline. CONCLUSIONS: Higher plasma citrate and succinate are associated with worse cross-sectional and longitudinal measures of neurocognitive function and gait speed that are age-dependent, supporting the importance of altered bioenergetic metabolism in the pathogenesis of NCI in older PWH.

The Pitt Bacteremia Score Predicts Mortality in Nonbacteremic Infections.

BACKGROUND: Predicting mortality risk in patients is important in research settings. The Pitt bacteremia score (PBS) is commonly used as a predictor of early mortality risk in patients with bloodstream infections (BSIs). We determined whether the PBS predicts 14-day inpatient mortality in nonbacteremia carbapenem-resistant Enterobacteriaceae (CRE) infections. METHODS: Patients were selected from the Consortium on Resistance Against Carbapenems in Klebsiella and Other Enterobacteriaceae, a prospective, multicenter, observational study. We estimated risk ratios to analyze the predictive ability of the PBS overall and each of its components individually. We analyzed each component of the PBS in the prediction of mortality, assessed the appropriate cutoff value for the dichotomized score, and compared the predictive ability of the qPitt score to that of the PBS. RESULTS: In a cohort of 475 patients with CRE infections, a PBS ≥4 was associated with mortality in patients with nonbacteremia infections (risk ratio [RR], 21.9; 95% confidence interval [CI], 7.0, 68.8) and with BSIs (RR, 6.0; 95% CI, 2.5, 14.4). In multivariable analysis, the hypotension, mechanical ventilation, mental status, and cardiac arrest parameters of the PBS were independent risk factors for 14-day all-cause inpatient mortality. The temperature parameter as originally calculated for the PBS was not independently associated with mortality. However, a temperature <36.0°C vs ≥36°C was independently associated with mortality. A qPitt score ≥2 had similar discrimination as a PBS ≥4 in nonbacteremia infections. CONCLUSIONS: Here, we validated that the PBS and qPitt score can be used as reliable predictors of mortality in nonbacteremia CRE infections.

Plasma Cystatin C Associates With HIV-Associated Neurocognitive Disorder but Is a Poor Diagnostic Marker in Antiretroviral Therapy-Treated Individuals.

OBJECTIVE: To examine associations between plasma cystatin C and neurocognitive impairment (NCI) and its performance as a diagnostic marker before and during initial antiretroviral therapy (ART). METHODS: Multivariable logistic regression and generalized estimating equations examined associations with NCI, determined by neuropsychological measurements, in participants of a 48-week randomized clinical trial of initial ART. Receiver operator characteristic curves examined diagnostic models of NCI. RESULTS: Cystatin C was associated with NCI before ART [odds ratio (OR) 3.4 (95% CI: 1.2 to 9.4) for each 2-fold increase in baseline levels] and during 48 weeks of ART, in models that excluded baseline measurements [OR 3.0 (1.2 to 7.8) for each 2-fold increase in time-updated levels]. The strength of association increased with more severe impairment using HIV-associated neurocognitive disorder criteria [OR 2.2 (0.8 to 6.0) with asymptomatic NCI and OR 4.0 (1.5 to 11.0) with mild neurocognitive disorder or HIV-associated dementia vs. no impairment, for each 2-fold increase in time-updated levels] or by global development score [OR 2.6 (1.1 to 6.3) with mild impairment and OR 4.6 (1.1 to 18.9) with moderate or severe impairment vs. no impairment]. Cystatin C performed poorly as a diagnostic marker for NCI, however, with an area under the receiver operator characteristic curve of 0.58 at baseline and 0.54 at week 48. CONCLUSIONS: Higher plasma cystatin C levels were significantly associated with NCI, but these levels did not seem to be useful as a diagnostic marker for this condition.

The Role of Trimethoprim/Sulfamethoxazole in the Treatment of Infections Caused by Carbapenem-Resistant Enterobacteriaceae.

In the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), trimethoprim-sulfamethoxazole (TMP-SMX) had a limited role in the treatment of less severe carbapenem-resistant Enterobacteriaceae (CRE) infections, especially urinary tract infections. Of tested CRE, only 29% were susceptible to TMP-SMX. Development of resistance further limits the use of TMP-SMX in CRE infections.

Women have enhanced bone loss associated with phosphaturia and CD4+ cell restoration during initial antiretroviral therapy.

OBJECTIVE: We compared bone mineral density (BMD) changes and their correlates, between men and women participating in two randomized trials of initial [antiretroviral therapy (ART)] regimens, with or without tenofovir disoproxil fumarate (TDF). METHODS: Covariates in linear regression models of 48-week hip and spine %BMD changes, by dual energy X-ray absorptiometry, included baseline and 48-week changes in plasma viral load, CD4 cells, plasma C-terminal telopeptide, procollagen 1 N-terminal propeptide and glomerular filtration rates, and the 48-week area under the curve of fractional excretion of phosphate. RESULTS: Despite overall hip and spine BMD declines of 2.8 and 2.9%, respectively, plasma viral load suppression to less than 50 vs. at least 50 copies/ml was associated 1.0% (P = 0.02) and 0.8% (P = 0.01) less BMD decline. Women had lower baseline spine (P = 0.04; n = 59 women, 418 men) and hip BMD (P = 0.01) in adjusted models, with 1.7% more hip decline on ART than men (P = 0.001). Serum phosphate was positively associated with baseline spine BMD in women (P = 0.03) but not men, and area under the curve of fractional excretion of phosphate was negatively associated with spine BMD changes, particularly in women randomized to TDF regimens (P = 0.03 and 0.054 for interactions by sex, and randomization to TDF vs. non-TDF regimens, respectively; n = 44 women, 326 men). Women also had 0.6% (P = 0.004) more hip BMD decline than men associated with each 100 CD4 cells/µl increase on ART (P = 0.02; n = 49 women, 379 men). CONCLUSION: Women randomized to TDF-containing ART had accentuated spine loss associated with phosphaturia, and accentuated hip loss associated with CD4 restoration, regardless of TDF exposure. Viral load suppression reduced bone loss.

Colistin Versus Ceftazidime-Avibactam in the Treatment of Infections Due to Carbapenem-Resistant Enterobacteriaceae.

Background: The efficacy of ceftazidime-avibactam-a cephalosporin-ß-lactamase inhibitor combination with in vitro activity against Klebsiella pneumoniae carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CRE)-compared with colistin remains unknown. Methods: Patients initially treated with either ceftazidime-avibactam or colistin for CRE infections were selected from the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), a prospective, multicenter, observational study. Efficacy, safety, and benefit-risk analyses were performed using intent-to-treat analyses with partial credit and the desirability of outcome ranking approaches. The ordinal efficacy outcome was based on disposition at day 30 after starting treatment (home vs not home but not observed to die in the hospital vs hospital death). All analyses were adjusted for confounding using inverse probability of treatment weighting (IPTW). Results: Thirty-eight patients were treated first with ceftazidime-avibactam and 99 with colistin. Most patients received additional anti-CRE agents as part of their treatment. Bloodstream (n = 63; 46%) and respiratory (n = 30; 22%) infections were most common. In patients treated with ceftazidime-avibactam versus colistin, IPTW-adjusted all-cause hospital mortality 30 days after starting treatment was 9% versus 32%, respectively (difference, 23%; 95% bootstrap confidence interval, 9%-35%; P = .001). In an analysis of disposition at 30 days, patients treated with ceftazidime-avibactam, compared with those treated within colistin, had an IPTW-adjusted probability of a better outcome of 64% (95% confidence interval, 57%-71%). Partial credit analyses indicated uniform superiority of ceftazidime-avibactam to colistin. Conclusions: Ceftazidime-avibactam may be a reasonable alternative to colistin in the treatment of K. pneumoniae carbapenemase-producing CRE infections. These findings require confirmation in a randomized controlled trial.

Pre-vaccine plasma levels of soluble inflammatory indices negatively predict responses to HAV, HBV, and tetanus vaccines in HCV and HIV infection.

BACKGROUND: Chronic hepatitis C virus (HCV) and HIV infections are associated with impaired responses to neo-antigens contained in hepatitis A virus (HAV)/hepatitis B virus (HBV) vaccines, yet responsible mechanisms are unclear. METHODS: ACTG 5232 and CFAR0910 were clinical trials where pre-vaccine levels of plasma IP10, IL-6, sCD163 and sCD14 were measured in viremic HCV- (n = 15) or HIV-infected participants (n = 24) and uninfected controls (n = 10). Accelerated dosing HAV/HBV vaccine and tetanus booster were administered and antibody response was measured at 0, 1, 3, 8, and 24 weeks. RESULTS: Pre-vaccine plasma IP10, IL-6, and sCD14 levels were elevated in both HCV and HIV-infected participants, while sCD163 was also elevated in HCV-infected participants. Pre-immunization tetanus antibody levels were lower in HIV-infected than in uninfected participants, while vaccine induced antibody responses were intact in HCV and HIV-infected participants. After HAV/HBV vaccination, HCV and HIV-infected participants had lower and less durable HAV and HBV antibody responses than uninfected controls. Among HCV-infected participants, pre-vaccine plasma IP10, IL-6, sCD14, and sCD163 levels inversely correlated with HAV, HBV and tetanus antibody responses after vaccine. Low HAV/HBV vaccine responses in HIV-infected participants prohibited assessment of immune correlates. CONCLUSIONS: During HCV and HIV infection markers of systemic inflammation reflect immune dysfunction as demonstrated by poor response to HAV/HBV neo-antigen vaccine.

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.

A Prospective Observational Study of the Epidemiology, Management, and Outcomes of Skin and Soft Tissue Infections Due to Carbapenem-Resistant Enterobacteriaceae.

BACKGROUND: This study was performed to characterize the epidemiology, management, and outcomes of skin and soft tissue infection (SSTI) and colonization due to carbapenem-resistant Enterobacteriaceae (CRE). METHODS: Patients from the Consortium on Resistance Against Carbapenem in Klebsiella and Other Enterobacteriaceae (CRACKLE-1) from December 24, 2011 to October 1, 2014 with wound cultures positive for CRE were included in the study. Predictors of surgical intervention were analyzed. Molecular typing of isolates was performed using repetitive extragenic palindromic polymerase chain reaction (PCR). Carbapenemase genes were detected using PCR. RESULTS: One hundred forty-two patients were included: 62 had SSTI (44%) and 56% were colonized. Mean age was 61 years, and 48% were male: median Charlson score was 3 (interquartile range, 1-5). Forty-eight percent of patients were admitted from long-term care facilities (LTCFs), and 31% were from the community. Two strain types (ST258A and ST258B) were identified (73% of 45 tested). Carbapenemase genes were detected in 40 of 45 isolates (blaKPC-3 [47%], blaKPC-2 [42%]). Sixty-eight patients (48%) underwent surgical intervention, 63% of whom had SSTI. Patients admitted from LTCFs were less likely to undergo surgical intervention (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.18-0.71). In multivariable analysis, among patients with SSTI, those admitted from LTCFs were less likely to undergo debridement (OR, 0.18; 95% CI, 0.04-0.93). CONCLUSIONS: Patients admitted from LTCFs with CRE SSTI were less likely to undergo surgical intervention. Sixteen percent of the patients died, and approximately 50% of survivors required more intensive care upon discharge. These findings suggest a unique, impactful syndrome within the CRE infection spectrum. Further studies are needed to assess the role of surgical debridement in management of CRE-SSTI, particularly among LTCF residents.

The Impact of Statin and Angiotensin-Converting Enzyme Inhibitor/Angiotensin Receptor Blocker Therapy on Cognitive Function in Adults With Human Immunodeficiency Virus Infection.

BACKGROUND: Although statins, angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) are generally well tolerated, the impact of these therapies individually or in combination on the change in neurocognitive function in persons with human immunodeficiency virus infection is unknown. METHODS: The study included participants in the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials cohort participants not receiving a statin or ACEI/ARB within 30 days of first neurologic assessment (baseline), with assessments by NPZ-3 (z score of averaged Trailmaking A and B tests and digit symbol test [DST]) from ≥2 measurements. Marginal structural models estimated the causal effect of statin or ACEI/ARB initiation on neurocognitive function; initial constant slope was assumed during the first year of treatment and a second constant slope thereafter. RESULTS: Of 3949 eligible participants, 16% started therapy with a statin, 11% with an ACEI/ARB, and 5% with both. Statin therapy had no significant effect on the composite NPZ-3 (primary outcome), Trailmaking B test, or DST. A small, nonsignificant positive effect on the Trailmaking A test was seen during year 1 (estimate, 0.088; 95% confidence interval, -.010 to .187; P = .08) and a small but significant negative effect (-0.033; -.058 to -.009; P = .007) in each subsequent year. ACEI/ARB therapy had a significant negative effect on the DST (-0.117; 95% confidence interval, -.217 to .016; P = .02) during year 1 but minimal effect in subsequent years or on other neurocognitive domains. CONCLUSIONS: In summary, although modest declines in neurocognitive performance were seen in single domains with statin or ACEI/ARB therapy, we did not find consistent evidence that statins or ACEI/ARB have an effect on global neurocognitive function. Future studies should focus on long-term neurocognitive effects.

Human Immunodeficiency Virus and Aging in the Era of Effective Antiretroviral Therapy.

Persons living with HIV (PLWH) have accentuated risks for age-associated comorbidities. Compared to the general population, PLWH have a 2-fold higher risk of cardiovascular disease, a 3-fold increased risk of fracture, and a risk of kidney disease that is comparable to that in diabetes. Some comorbidities may present at younger ages than among the general population, suggesting the possibility of accelerated aging with HIV infection.

Association Between Frailty and Components of the Frailty Phenotype With Modifiable Risk Factors and Antiretroviral Therapy.

The impact of antiretroviral therapy (ART) on frailty among human immunodeficiency virus (HIV)-infected adults has not been well described. HIV-infected participants aged ≥40 years with initial ART receipt through a randomized, controlled AIDS Clinical Trials Group trial completed a frailty assessment. Ordinal logistic regression models examined factors associated with frailty. Of 1016 participants, 6% were frail, and 38% were prefrail. Frailty was associated with lower education, older age, Medicare/Medicaid, initial efavirenz, smoking, obesity, and neurocognitive impairment; physical activity and alcohol use were protective. The associations with ART require further investigation, and associations between frailty and modifiable factors provide targets for future interventions.

Disability Among Middle-Aged and Older Persons With Human Immunodeficiency Virus Infection.

BACKGROUND: Older human immunodeficiency virus (HIV)-infected adults may experience higher rates of frailty and disability than the general population. Improved understanding of the prevalence, risk factors, and types of impairment can better inform providers and the healthcare system. METHODS: HIV-infected participants within the AIDS Clinical Trials Group A5322 HAILO study self-reported disability by the Lawton-Brody Instrumental Activities of Daily Living (IADL) Questionnaire. Frailty was measured by 4-m walk time, grip strength, self-reported weight loss, exhaustion, and low activity. Logistic regression models identified characteristics associated with any IADL impairment. Agreement between IADL impairment and frailty was assessed using the weighted kappa statistic. RESULTS: Of 1015 participants, the median age was 51 years, 15% were aged ≥60 years, 19% were female, 29% black, and 20% Hispanic. At least 1 IADL impairment was reported in 18% of participants, most commonly with housekeeping (48%) and transportation (36%) and least commonly with medication management (5%). In multivariable models, greater disability was significantly associated with neurocognitive impairment, lower education, Medicare/Medicaid insurance (vs private/other coverage), smoking, and low physical activity. Although a greater proportion of frail participants had IADL impairment (52%) compared to non-frail (11%) persons, agreement was poor (weighted kappa <0.18, 95% confidence interval, 0.13, 0.23). CONCLUSION: IADL disability occurs frequently among middle-aged and older HIV-infected adults on effective antiretroviral therapy. Potentially modifiable risk factors (smoking, physical activity) provide targets for interventions to maintain independent living. Systematic recognition of persons at greater risk for disability can facilitate connection to resources that may help preserve independence.

Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae: Laboratory Detection and Impact on Mortality.

Background: Polymyxins including colistin are an important "last-line" treatment for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKp). Increasing use of colistin has led to resistance to this cationic antimicrobial peptide. Methods: A cohort nested within the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRACKLE) was constructed of patients with infection, or colonization with CRKp isolates tested for colistin susceptibility during the study period of December, 2011 to October, 2014. Reference colistin resistance determination as performed by broth macrodilution was compared to results from clinical microbiology laboratories (Etest) and to polymyxin resistance testing. Each patient was included once, at the time of their first colistin-tested CRKp positive culture. Time to 30-day in-hospital all-cause mortality was evaluated by Kaplan-Meier curves and Cox proportional hazard modeling. Results: In 246 patients with CRKp, 13% possessed ColR CRKp. ColR was underestimated by Etest (very major error rate = 35%, major error rate = 0.4%). A variety of rep-PCR strain types were encountered in both the ColS and the ColR groups. Carbapenem resistance was mediated primarily by blaKPC-2 (46%) and blaKPC-3 (50%). ColR was associated with increased hazard for in-hospital mortality (aHR 3.48; 95% confidence interval, 1.73-6.57; P < .001). The plasmid-associated ColR genes, mcr-1 and mcr-2 were not detected in any of the ColR CRKp. Conclusions: In this cohort, 13% of patients with CRKp presented with ColR CRKp. The apparent polyclonal nature of the isolates suggests de novo emergence of ColR in this cohort as the primary factor driving ColR. Importantly, mortality was increased in patients with ColR isolates.

Hospital Readmissions in Patients With Carbapenem-Resistant Klebsiella pneumoniae.

BACKGROUND: Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated ("CRKP readmission") potentially contribute to transmission of CRKP. OBJECTIVE: To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe). DESIGN: Cohort study from December 24, 2011, through July 1, 2013. SETTING: Multicenter consortium of acute care hospitals in the Great Lakes region. PATIENTS: All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture. METHODS: All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models. RESULTS: Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32-6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72-17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission. CONCLUSION: Hospitalized patients with CRKP-specifically those with a history of malignancy-are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.

Community-Acquired Pyelonephritis in Pregnancy Caused by KPC-Producing Klebsiella pneumoniae.

Carbapenem-resistant Enterobacteriaceae (CRE) usually infect patients with significant comorbidities and health care exposures. We present a case of a pregnant woman who developed community-acquired pyelonephritis caused by KPC-producing Klebsiella pneumoniae. Despite antibiotic treatment, she experienced spontaneous prolonged rupture of membranes, with eventual delivery of a healthy infant. This report demonstrates the challenge that CRE may pose to the effective treatment of common infections in obstetric patients, with potentially harmful consequences to maternal and neonatal health.