scholarly journals Epidemiology of Bloodstream Infections Caused by Acinetobacter baumannii and Impact of Drug Resistance to both Carbapenems and Ampicillin-Sulbactam on Clinical Outcomes

2013 ◽  
Vol 57 (12) ◽  
pp. 6270-6275 ◽  
Author(s):  
Teena Chopra ◽  
Dror Marchaim ◽  
Reda A. Awali ◽  
Amar Krishna ◽  
Paul Johnson ◽  
...  

ABSTRACTAcinetobacter baumanniihas become a leading cause of bloodstream infections (BSI) in health care settings. Although the incidence of infection with carbapenem- and ampicillin-sulbactam-resistant (CASR)A. baumanniihas increased, there is a scarcity of studies which investigate BSI caused by CASRA. baumannii. A retrospective cohort study was conducted on adult patients with BSI caused byA. baumanniiand who were admitted to the Detroit Medical Center between January 2006 and April 2009. Medical records were queried for patients' demographics, antimicrobial exposures, comorbidities, hospital stay, and clinical outcomes. Bivariate analyses and logistic regression were employed in the study. Two hundred seventy-four patients with BSI caused byA. baumanniiwere included in the study: 68 (25%) caused by CASRA. baumanniiand 206 (75%) caused by non-CASRA. baumannii. In multivariate analysis, factors associated with BSI caused by CASRA. baumanniiincluded admission with a rapidly fatal condition (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 1.27 to 6.32,Pvalue = 0.01) and prior use of antimicrobials (OR = 2.83, 95% CI = 1.18 to 6.78,Pvalue = 0.02). In-hospital mortality rates for BSI caused by CASRA. baumanniiwere significantly higher than those for non-CASRA. baumannii-induced BSI (43% versus 20%; OR = 3.0, 95% CI = 1.60 to 5.23,Pvalue < 0.001). However, after adjusting for potential confounders, the association between BSI caused by CASRA. baumanniiand increased risk of in-hospital mortality was not significant (OR = 1.15, 95% CI = 0.51 to 2.63,Pvalue = 0.74). This study demonstrated that CASRA. baumanniihad a distinct epidemiology compared to more susceptibleA. baumanniistrains; however, clinical outcomes were similar for the two groups. Admission with a rapidly fatal condition was an independent predictor for both CASRA. baumanniiand in-hospital mortality.

2011 ◽  
Vol 55 (10) ◽  
pp. 4844-4849 ◽  
Author(s):  
John S. Esterly ◽  
Milena Griffith ◽  
Chao Qi ◽  
Michael Malczynski ◽  
Michael J. Postelnick ◽  
...  

ABSTRACTNosocomialAcinetobacter baumanniibloodstream infections occur with significant prevalence and mortality. The relationship between carbapenem resistance inA. baumanniiand patient outcomes remains unclear. A retrospective cohort study was conducted on patients withA. baumanniibacteremia. Outcomes, controlling for confounders, were compared for carbapenem-nonresistantA. baumannii(CNRAB) and carbapenem-resistantA. baumannii(CRAB). The primary outcome studied was all-cause hospital mortality, and the secondary endpoints evaluated were time to mortality, time to negative cultures, and length of stay postinfection for survivors. A total of 79 patients, 37 infected with CRAB and 42 with CNRAB, were studied. Hospital mortality was greater in the CRAB group as determined based on bivariate analysis (P< 0.01); however, this effect was nullified when controlling for relevant confounders with logistic regression and a Cox proportional-hazards model (P= 0.71 and 0.75, respectively). Values for time to mortality and time to negative cultures did not differ between the groups. The median number of days of stay postinfection for survivors was greater for the CRAB group than the CNRAB group (14 versus 6.5;P< 0.01). Patients who received active antimicrobial therapy were less likely to die (93.5% versus 74.2%;P= 0.02), regardless of carbapenem susceptibility classifications, and this result was robust in the multivariate model (P= 0.02). Trends existed for improved outcomes in patients receiving an active beta-lactam, and patients fared worse if they had received a polymyxin as an active agent. Patients with CRAB bloodstream infections were more chronically ill and had more comorbidities. Inactive therapy was more important than carbapenem susceptibility with respect to outcomes, was a strong predictor of death, and is potentially modifiable.


Author(s):  
Deborah L. Benzil ◽  
Mehran Saboori ◽  
Alon Y. Mogilner ◽  
Ronald Rocchio ◽  
Chitti R. Moorthy

Object. The extension of stereotactic radiosurgery treatment of tumors of the spine has the potential to benefit many patients. As in the early days of cranial stereotactic radiosurgery, however, dose-related efficacy and toxicity are not well understood. The authors report their initial experience with stereotactic radiosurgery of the spine with attention to dose, efficacy, and toxicity. Methods. All patients who underwent stereotactic radiosurgery of the spine were treated using the Novalis unit at Westchester Medical Center between December 2001 and January 2004 are included in a database consisting of demographics on disease, dose, outcome, and complications. A total of 31 patients (12 men, 19 women; mean age 61 years, median age 63 years) received treatment for 35 tumors. Tumor types included 26 metastases (12 lung, nine breast, five other) and nine primary tumors (four intradural, five extradural). Thoracic tumors were most common (17 metastases and four primary) followed by lumbar tumors (four metastases and four primary). Lesions were treated to the 85 to 90% isodose line with spinal cord doses being less than 50%. The dose per fraction and total dose were selected on the basis of previous treatment (particularly radiation exposure), size of lesion, and proximity to critical structures. Conclusions. Rapid and significant pain relief was achieved after stereotactic radiosurgery in 32 of 34 treated tumors. In patients treated for metastases, pain was relieved within 72 hours and remained reduced 3 months later. Pain relief was achieved with a single dose as low as 500 cGy. Spinal cord isodoses were less than 50% in all patients except those with intradural tumors (mean single dose to spinal cord 268 cGy and mean total dose to spinal cord 689 cGy). Two patients experienced transient radiculitis (both with a biological equivalent dose (BED) > 60 Gy). One patient who suffered multiple recurrences of a conus ependymoma had permanent neurological deterioration after initial improvement. Pathological evaluation of this lesion at surgery revealed radiation necrosis with some residual/recurrent tumor. No patient experienced other organ toxicity. Stereotactic radiosurgery of the spine is safe at the doses used and provides effective pain relief. In this study, BEDs greater than 60 Gy were associated with an increased risk of radiculitis.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S137-S137
Author(s):  
Stephanie Wo ◽  
Yanina Dubrovskaya ◽  
Justin Siegfried ◽  
John Papadopoulos ◽  
Shin-Pung Jen

Abstract Background Viridans group streptococci (VGS) is an infrequent yet significant cause of bloodstream infections, and complicated cases may require prolonged antibiotic therapy. Ceftriaxone (CTX) and penicillin G (PCN G) are both considered first line options for VGS infections, but comparisons between these agents are limited. We evaluated the clinical outcomes amongst patients treated with CTX and PCN G for complicated VGS bacteremia. Methods This was a single-center, retrospective study of adult patients with ≥1 positive VGS blood culture who were treated with either CTX or PCN G/ampicillin (both included in PCN G arm) between January 2013 and June 2019. The primary outcome was a composite of safety endpoints, including hospital readmission due to VGS or an adverse event (AE) from therapy, Clostridioides difficile infections, treatment modification or discontinuation due to an antibiotic-related AE, and development of extended-spectrum beta lactamase resistance. Secondary outcomes included the individual safety endpoints, VGS bacteremia recurrence, hospital readmission, and all-cause mortality. Results Of 328 patients screened for inclusion, 94 patients met eligibility criteria (CTX n= 64, PCN G n=34). Median age was 68 years (IQR 56–81) and 68% were male. Study patients did not present with critical illness, as reflected by a median Pitt bacteremia score of 0 in the CTX and 1 in the PCN G arms, P=0.764. Streptococcus mitis was the most common VGS isolate and infective endocarditis (IE) was the predominant source of infection. CTX was not significantly associated with increased risk of the primary outcome (14% vs. 27%; P= 0.139). The driver of the composite outcome was hospital readmission due to VGS bacteremia or therapy complications. Results were similar in the subgroup of patients with IE (12.5% vs. 23.5%). No secondary endpoints differed significantly between groups. On multivariate analysis, source removal was a protective factor of the primary outcome (OR 0.1; 95% CI 0.020–0.6771; P= 0.017). Conclusion Despite potential safety concerns with the prolonged use of CTX in complicated VGS bacteremia, this study did not demonstrate a higher rate of treatment failure, adverse events, or resistance. These findings warrant further exploration. Disclosures All Authors: No reported disclosures


mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Krishna Rao ◽  
Peter D. R. Higgins ◽  
Vincent B. Young

ABSTRACTRecurrentClostridium difficileinfection (rCDI) frequently complicates recovery from CDI. Accurately predicting rCDI would allow judicious allocation of limited resources, but published models have met with limited success. Thus, biomarkers predictive of recurrence have been sought. This study tested whether PCR ribotype independently predicted rCDI. Stool samples from nonpregnant inpatients ≥18 years of age with diarrhea were included from October 2010 to January 2013 after the patients tested positive forC. difficilein the clinical microbiology laboratory. Per guidelines, the rCDI was defined as a positive test forC. difficileat >2 weeks but ≤8 weeks from the index episode. For each sample, a single colony ofC. difficilewas isolated by anaerobic culture, confirmed to be toxigenic by PCR, and ribotyped. Simple logistic regression and multiple logistic regression were used to model the primary outcome of rCDI, incorporating a wide range of clinical parameters. In total, 927 patients with 968 index episodes of CDI were included, with 110 (11.4%) developing rCDI. Age and use of proton pump inhibitors or concurrent antibiotics did not increase the risk of rCDI. Low serum bilirubin levels and ribotype 027 were associated with increased risk of rCDI on unadjusted analysis, with health care-associated CDI being inversely associated. In the final multivariable model, ribotype 027 was the strongest independent predictor of rCDI (odds ratio, 2.17; 95% confidence interval, 1.33 to 3.56;P= 0.002). Ribotype 027 is an independent predictor of rCDI.IMPORTANCECDI is a major public health issue, with over 400,000 cases per year in the United States alone. Recurrent CDI is common, occurring in approximately one in five individuals after a primary episode. Although interventions exist that could reduce the risk of recurrence, deployment in all patients is limited by cost, invasiveness, and/or an undetermined long-term safety profile. Thus, clinicians need risk stratification tools to properly allocate treatments. Because prior research on clinical predictors has failed to yield a reliable, reproducible, and effective predictive model to assist treatment decisions, accurate biomarkers of recurrence would be of great value. This study tested whether PCR ribotype independently predicted rCDI, and the data build upon prior research in showing that ribotype 027 is associated with rCDI.


2012 ◽  
Vol 56 (11) ◽  
pp. 5961-5970 ◽  
Author(s):  
Luísa C. S. Antunes ◽  
Francesco Imperi ◽  
Fabrizia Minandri ◽  
Paolo Visca

ABSTRACTMultidrug-resistantAcinetobacter baumanniiposes a tremendous challenge to traditional antibiotic therapy. Due to the crucial role of iron in bacterial physiology and pathogenicity, we investigated iron metabolism as a possible target for anti-A. baumanniichemotherapy using gallium as an iron mimetic. Due to chemical similarity, gallium competes with iron for binding to several redox enzymes, thereby interfering with a number of essential biological reactions. We found that Ga(NO3)3, the active component of an FDA-approved drug (Ganite), inhibits the growth of a collection of 58A. baumanniistrains in both chemically defined medium and human serum, at concentrations ranging from 2 to 80 μM and from 4 to 64 μM, respectively. Ga(NO3)3delayed the entry ofA. baumanniiinto the exponential phase and drastically reduced bacterial growth rates. Ga(NO3)3activity was strongly dependent on iron availability in the culture medium, though the mechanism of growth inhibition was independent of dysregulation of gene expression controlled by the ferric uptake regulator Fur. Ga(NO3)3also protectedGalleria mellonellalarvae from lethalA. baumanniiinfection, with survival rates of ≥75%. At therapeutic concentrations for humans (28 μM plasma levels), Ga(NO3)3inhibited the growth in human serum of 76% of the multidrug-resistantA. baumanniiisolates tested by ≥90%, raising expectations on the therapeutic potential of gallium for the treatment ofA. baumanniibloodstream infections. Ga(NO3)3also showed strong synergism with colistin, suggesting that a colistin-gallium combination holds promise as a last-resort therapy for infections caused by pan-resistantA. baumannii.


2013 ◽  
Vol 58 (2) ◽  
pp. 828-832 ◽  
Author(s):  
Spyros Pournaras ◽  
Aggeliki Poulou ◽  
Konstantina Dafopoulou ◽  
Yassine Nait Chabane ◽  
Ioulia Kristo ◽  
...  

ABSTRACTTwo colistin-susceptible/colistin-resistant (Cols/Colr) pairs ofAcinetobacter baumanniistrains assigned to international clone 2, which is prevalent worldwide, were sequentially recovered from two patients after prolonged colistin administration. Compared with the respective Colsisolates (Ab248 and Ab299, both having a colistin MIC of 0.5 μg/ml), both Colrisolates (Ab249 and Ab347, with colistin MICs of 128 and 32 μg/ml, respectively) significantly overexpressedpmrCABgenes, had single-amino-acid shifts in the PmrB protein, and exhibited significantly slower growth. The Colrisolate Ab347, tested by proteomic analysis in comparison with its Colscounterpart Ab299, underexpressed the proteins CsuA/B and C from thecsuoperon (which is necessary for biofilm formation). This isolate also underexpressed aconitase B and different enzymes involved in the oxidative stress response (KatE catalase, superoxide dismutase, and alkyl hydroperoxide reductase), suggesting a reduced response to reactive oxygen species (ROS) and, consequently, impaired colistin-mediated cell death through hydroxyl radical production. Colsisolates that were indistinguishable by macrorestriction analysis from Ab299 caused six sequential bloodstream infections, and isolates indistinguishable from Ab248 caused severe soft tissue infection, while Colrisolates indistinguishable from Ab347 and Ab249 were mainly colonizers. In particular, a Colsisolate identical to Ab299 was still invading the bloodstream 90 days after the colonization of this patient by Colrisolates. These observations indicate considerably lower invasiveness ofA. baumanniiclinical isolates following the development of colistin resistance.


2016 ◽  
Vol 60 (11) ◽  
pp. 6892-6895 ◽  
Author(s):  
Derek N. Bremmer ◽  
Karri A. Bauer ◽  
Stephanie M. Pouch ◽  
Keelie Thomas ◽  
Debra Smith ◽  
...  

ABSTRACTWe tested 76 extensively drug-resistant (XDR)Acinetobacter baumanniiisolates by the checkerboard method using only wells containing serum-achievable concentrations (SACs) of drugs. Checkerboard results were correlated by time-kill assay and clinical outcomes. Minocycline-colistin was the best combinationin vitro, as it inhibited growth in one or more SAC wells in all isolates. Patients who received a combination that inhibited growth in one or more SAC wells demonstrated better microbiological clearance than those who did not (88% versus 30%;P= 0.025). The checkerboard platform may have clinical utility for XDRA. baumanniiinfections.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S271-S271
Author(s):  
Gauri Chauhan ◽  
Nikunj M Vyas ◽  
Todd P Levin ◽  
Sungwook Kim

Abstract Background Vancomycin-resistant Enterococci (VRE) occurs with enhanced frequency in hospitalized patients and are usually associated with poor clinical outcomes. The purpose of this study was to evaluate the risk factors and clinical outcomes of patients with VRE infections. Methods This study was an IRB-approved multi-center retrospective chart review conducted at a three-hospital health system between August 2016-November 2018. Inclusion criteria were patients ≥18 years and admitted for ≥24 hours with cultures positive for VRE. Patients pregnant or colonized with VRE were excluded. The primary endpoint was to analyze the association of potential risk factors with all-cause in-hospital mortality (ACM) and 30-day readmission. The subgroup analysis focused on the association of risk factors with VRE bacteremia. The secondary endpoint was to evaluate the impact of different treatment groups of high dose daptomycin (HDD) (≥10 mg/kg/day) vs. low dose daptomycin (LDD) (< 10 mg/kg/day) vs. linezolid (LZD) on ACM and 30-day readmission. Subgroup analysis focused on the difference of length of stay (LOS), length of therapy (LOT), duration of bacteremia (DOB) and clinical success (CS) between the treatment groups. Results There were 81 patients included for analysis; overall mortality was observed at 16%. Utilizing multivariate logistic regression analyses, patients presenting from long-term care facilities (LTCF) were found to have increased risk for mortality (OR 4.125, 95% CI 1.149–14.814). No specific risk factors were associated with 30-day readmission. Patients with previous exposure to fluoroquinolones (FQ) and cephalosporins (CPS), nosocomial exposure and history of heart failure (HF) showed association with VRE bacteremia. ACM was similar between HDD vs. LDD vs. LZD (16.7% vs. 15.4% vs. 0%, P = 0.52). No differences were seen between LOS, LOT, CS, and DOB between the groups. Conclusion Admission from LTCFs was a risk factor associated with in-hospital mortality in VRE patients. Individuals with history of FQ, CPS and nosocomial exposure as well as history of HF showed increased risk of acquiring VRE bacteremia. There was no difference in ACM, LOS, LOT, and DOB between HDD, LDD and LZD. Disclosures All authors: No reported disclosures.


2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 413-418 ◽  
Author(s):  
Deborah L. Benzil ◽  
Mehran Saboori ◽  
Alon Y. Mogilner ◽  
Ronald Rocchio ◽  
Chitti R. Moorthy

Object. The extension of stereotactic radiosurgery treatment of tumors of the spine has the potential to benefit many patients. As in the early days of cranial stereotactic radiosurgery, however, dose-related efficacy and toxicity are not well understood. The authors report their initial experience with stereotactic radiosurgery of the spine with attention to dose, efficacy, and toxicity. Methods. All patients who underwent stereotactic radiosurgery of the spine were treated using the Novalis unit at Westchester Medical Center between December 2001 and January 2004 are included in a database consisting of demographics on disease, dose, outcome, and complications. A total of 31 patients (12 men, 19 women; mean age 61 years, median age 63 years) received treatment for 35 tumors. Tumor types included 26 metastases (12 lung, nine breast, five other) and nine primary tumors (four intradural, five extradural). Thoracic tumors were most common (17 metastases and four primary) followed by lumbar tumors (four metastases and four primary). Lesions were treated to the 85 to 90% isodose line with spinal cord doses being less than 50%. The dose per fraction and total dose were selected on the basis of previous treatment (particularly radiation exposure), size of lesion, and proximity to critical structures. Conclusions. Rapid and significant pain relief was achieved after stereotactic radiosurgery in 32 of 34 treated tumors. In patients treated for metastases, pain was relieved within 72 hours and remained reduced 3 months later. Pain relief was achieved with a single dose as low as 500 cGy. Spinal cord isodoses were less than 50% in all patients except those with intradural tumors (mean single dose to spinal cord 268 cGy and mean total dose to spinal cord 689 cGy). Two patients experienced transient radiculitis (both with a biological equivalent dose (BED) > 60 Gy). One patient who suffered multiple recurrences of a conus ependymoma had permanent neurological deterioration after initial improvement. Pathological evaluation of this lesion at surgery revealed radiation necrosis with some residual/recurrent tumor. No patient experienced other organ toxicity. Stereotactic radiosurgery of the spine is safe at the doses used and provides effective pain relief. In this study, BEDs greater than 60 Gy were associated with an increased risk of radiculitis.


2019 ◽  
Vol 40 (24) ◽  
pp. 1942-1951 ◽  
Author(s):  
Dániel Aradi ◽  
Lisa Gross ◽  
Dietmar Trenk ◽  
Tobias Geisler ◽  
Béla Merkely ◽  
...  

Abstract Aims The value of platelet function testing (PFT) in predicting clinical outcomes and guiding P2Y12-inhibitor treatment is uncertain. In a pre-specified sub-study of the TROPICAL-ACS trial, we assessed ischaemic and bleeding risks according to high platelet reactivity (HPR) and low platelet reactivity (LPR) to ADP in patients receiving uniform prasugrel vs. PFT-guided clopidogrel or prasugrel. Methods and results Acute coronary syndrome patients with PFT done 14 days after hospital discharge were included with prior randomization to uniform prasugrel for 12 months (control group, no treatment modification) vs. early de-escalation from prasugrel to clopidogrel and PFT-guided maintenance treatment (HPR: switch-back to prasugrel, non-HPR: clopidogrel). The composite ischaemic endpoint included cardiovascular death, myocardial infarction, or stroke, while key safety outcome was Bleeding Academic Research Consortium (BARC) 2–5 bleeding, from PFT until 12 months. We identified 2527 patients with PFT results available: 1266 were randomized to the guided and 1261 to the control group. Before treatment adjustment, HPR was more prevalent in the guided group (40% vs. 15%), while LPR was more common in control patients (27% vs. 11%). Compared to control patients without HPR on prasugrel (n = 1073), similar outcomes were observed in guided patients kept on clopidogrel [n = 755, hazard ratio (HR): 1.06 (0.57–1.95), P = 0.86] and also in patients with HPR on clopidogrel switched to prasugrel [n = 511, HR: 0.96 (0.47–1.96), P = 0.91]. In contrast, HPR on prasugrel was associated with a higher risk for ischaemic events in control patients [n = 188, HR: 2.16 (1.01–4.65), P = 0.049]. Low platelet reactivity was an independent predictor of bleeding [HR: 1.74 (1.18–2.56), P = 0.005], without interaction (Pint = 0.76) between study groups. Conclusion Based on this substudy of a randomized trial, selecting prasugrel or clopidogrel based on PFT resulted in similar ischaemic outcomes as uniform prasugrel therapy without HPR. Although infrequent, HPR on prasugrel was associated with increased risk of ischaemic events. Low platelet reactivity was a strong and independent predictor of bleeding both on prasugrel and clopidogrel.


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