bluuebunny/crossref_metadata_2025_split huggingface dataset:
501. Risk of Infection in Persons Colonized with Carbapenemase-Producing Enterobacteriales (CPE) in Ontario, Canada
Authors: Faheem Amna , Jamal Alainna , Kazi Hassan , Coleman Brenda , Farooqi Lubna , Johnstone Jennie , Katz Kevin , Li Angel , Melano Roberto , Mubareka Samira , Muller Matthew P , Patel Samir , Paterson Aimee , Poutanen Susan , Rebbapragada Anu , Richardson David , Sarabia Alicia , Zhong Zoe , McGeer Allison 
Published: October 2019

Abstract

Background
We aimed to assess the risk of subsequent infection among patients colonized by CPE.

Methods
The Toronto Invasive Bacterial Diseases Network (TIBDN) has conducted population-based surveillance for CPE colonization/infection in Toronto and Peel region, Ontario, Canada, since CPE were first identified (2007). All laboratories report all CPE isolates to TIBDN. Clinical data are collected via patient interview and hospital chart review. Initially colonized patients are followed for 5y; subsequent CPE infection is defined as an episode with onset >3 days after initial detection of CPE colonization that meets National Healthcare Safety Network criteria for infection with a clinical isolate of CPE.

Results
From 2007 to 2018, 790 persons with CPE colonization/infection were identified. Among 364 cases colonized at identification, 42 (12%) subsequently had at least one clinical isolate, and 23 (6%) had an infection: 8 with bacteremia (primary or secondary), 7 UTI, 5 pneumonia, and 3 other. The median time from identification of colonization to infection was 21 days (IQR 7–38), with a probability of developing an infection of 7% at 3 months, and 18% by 3 years (figure). In 305 cases with data available to date, older persons, those admitted to the ICU, and those with current/recent invasive medical devices were more likely to develop infection (table). Gender, underlying conditions and other procedures were not associated with risk of infection. There was a trend to infections being more likely in patients colonized with K. pneumoniae (52% vs. 35%, P = 0.13).

Conclusion
The risk of subsequent infection in our cohort was 18%, with highest risk in the first 3 months; most infections occurred in patients requiring intensive care unit admission and invasive medical devices.

Disclosures
All authors: No reported disclosures.
504. Epidemiology of End-stage Renal Disease (ESRD) Patients with Carbapenem-Resistant Enterobacteriaceae (CRE) Infections: Atlanta Metropolitan Area, 2012–2017
Authors: Hurd Jacqueline M , Bower Chris W , Jacob Jesse T 
Published: October 2019

Abstract

Background
Patients with end-stage renal disease (ESRD) have higher risks for resistant organisms including carbapenem-resistant Enterobacteriaceae (CRE). To explore the effect of ESRD on CRE, we compared characteristics of CRE cases with and without ESRD in a population-based cohort.

Methods
The Georgia Emerging Infections Program has performed active laboratory- and population-based surveillance for CRE in metropolitan Atlanta (4.1 million in 2017) since 2012. CRE cases are defined by isolation from a sterile body site or urine of E. coli, K. pneumoniae, K. oxytoca, K. aerogenes, or E. cloacae. From 2012 to 2015, cultures were resistant to all third-generation cephalosporins tested and non-susceptible to ≥1 carbapenem (excluding ertapenem). After 2016, cultures were resistant to ≥1 carbapenems. Epidemiologic data including ESRD were collected via medical chart review. ESRD population data were obtained from the US Renal Data System. Georgia vital records data were used to determine 90-day mortality rates. Prevalence estimates were calculated. Comparisons used a χ 2 test.

Results
Of 1,511 CRE cases, 136 (9%) were on current chronic dialysis, 128 (94%) of which were on hemodialysis (HD) and 5 (4%) were on peritoneal dialysis. Among CRE cases with HD, 94 (73%) had a catheter and 30 (23%) had an arteriovenous fistula or graft. CRE cases with ESRD were more likely to be male (58% vs. 40%), black (76% vs. 38%), and have diabetes (67% vs. 38%), congestive heart failure (25% vs. 17%), or peripheral arterial disease (12% vs. 4%). CRE cases with ESRD had more hospitalizations within 30 days of the culture date (77% vs. 47%), ICU admissions prior to (29% vs. 7%) or after the culture date (43% vs. 14%) and discharges to LTCFs (35% vs. 15%) after hospitalization. CRE cases with ESRD and bacteremia were more likely to have been hospitalized >3 days before the culture compared with CRE cases with ESRD and positive cultures from other body sites (52% vs. 24%). The 90-day mortality rate per 100,000 population was higher among CRE cases with ESRD (100.9 cases) than without ESRD (1.0 cases).

Conclusion
Among a population-based cohort of patients with CRE infections, ESRD comprised ~10% but had markedly mortality, suggesting that future interventions should target ESRD.

Disclosures
All authors: No reported disclosures.
508. Gentamicin Non-susceptibility is Associated with Persistence of Carbapenem-Resistant Klebsiella pneumoniae in the Urinary Tract
Authors: Luterbach Courtney , Henderson Heather , Cober Eric , Richter Sandra S , Salata Robert A , Kaye Keith S , Doi Yohei , Watkins Richard R , Bonomo Robert A , van Duin David 
Published: October 2019

Abstract

Background
Urinary tract infection (UTI) is the most common clinical manifestation of carbapenem-resistant Klebsiella pneumoniae (CRKp). Persistent CRKp bacteriuria is associated with the spread of CRKp and antibiotic overuse. Risk factors for persistent CRKp bacteriuria are uncertain.

Methods
CRACKLE-1 was a multicenter, prospective study that included 960 patients with at least one carbapenem-resistant Enterobacteriaceae (CRE)-positive culture from December 2011 to June 2016 collected from 18 hospitals encompassing 8 healthcare systems in the Midwestern US and North Carolina. Patients with CRKp bacteriuria who were discharged alive from index hospitalization were included in the current study, and sporadic (single positive CRKp urine culture) and persistent (≥2 CRKp urine cultures during independent hospital admissions occurring at least 2 days apart) cases were compared. Antibiotic susceptibility testing was performed by local laboratories. Amikacin, gentamicin (GENT), and trimethoprim/sulfamethoxazole were included in the analysis based on variance and frequency of testing. The CDC/National Healthcare Safety Network criteria for UTI were used.

Results
CRKp was the most common CRE isolate (n = 869, prevalence 91%). In patients with CRKp, 527 had CRKp isolated from the urine (prevalence 61%, 95% CI 0.57, 0.64). Of these, 486 patients, of whom 129 (27%) were diagnosed with a UTI, were discharged alive. Notably, 135/486 (28%) patients with CRKp bacteriuria were readmitted and yielded a second urine culture of CRKp. Most patients with persistent bacteriuria, 99/135 (73%), were asymptomatic at initial admission. Of these patients, 20/99 (20%) were diagnosed with a UTI at second admission. In multivariable analysis, only GENT non-susceptibility was associated with an increased risk (adjusted OR 1.66, 95% CI 1.10–2.49) of persistent bacteriuria. Persistent bacteriuria was independent of GENT treatment during index hospitalization (GENT was used in 15% of patients).

Conclusion
Bacteriuria with GENT non-susceptible CRKp strains was associated with persistent bacteriuria. As this was independent of GENT treatment, GENT resistance determinants may be co-transmitted along with traits that promote bacterial persistence in CRKp.

Disclosures
All authors: No reported disclosures.
518. Comparing the Mortality of Carbapenemase-Producing and Non-Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae Bacteremia
Authors: Seo Hyeonji , Yang Eunmi , Bae Seongman , Chung Hyemin , Cho Eunbeen , Lee Sang-Oh , Choi Sang-Ho , Soo Kim Yang , Kim Sung-Han , Hee Woo Jun , Jung Jiwon , Jae Kim Min , Sung Heungsup , Kim Mi-Na , Park Su-Jin , Pil Chong Yong 
Published: October 2019

Abstract

Background
Carbapenem-resistant Enterobacteriaceae (CRE) infection is an emerging clinical issue. One of the mechanisms of carbapenem-resistance is carbapenemase production. This study aimed to identify whether clinical outcomes differ by CRE resistance mechanism and to evaluate risk factors for mortality in patients with CRE bacteremia.

Methods
We conducted a retrospective cohort study comparing 14-day mortality between patients with carbapenemase-producing (CP)-CRE and non-CP-CRE bacteremia during January 2011 to October 2018. Only monomicrobial Escherichia coli or Klebsiella pneumoniae bacteremia were included in the study. A modified carbapenem inactivation method was used for phenotypic detection of carbapenemase production. The presence of a variety of carbapenemase genes was evaluated by PCR with specific primers.

Results
Of 134 patients with monomicrobial CRE bacteremia, 48 (35.8%) were infected with CP-CRE, and 86 (64.1%) were infected with non-CP-CRE. The most common carbapenemase in CP-CRE isolates was KPC (66.7%), followed by NDM-1 (18.8%), OXA-48-like (10.4%), and VIM (4.1%). Baseline characteristics were similar between the two groups (Table 1). However, the CP-CRE group was significantly more likely to undergo removal of eradicable foci and to have meropenem MIC >8 µg/mL. A total of 33 (24.6%) patients died within 14 days, including 9 (18.8%) in the CP-CRE group and 24 (27.9%) in the non-CP-CRE group. Deceased patients were more likely to have a higher Pitt bacteremia score, nosocomial acquisition, ineradicable or not-eradicated foci, immunosuppressant use, inappropriate definitive treatment (Table 2). Combination therapy for definitive treatment was associated with decreased mortality. In a multivariate analysis including carbapenemase production, a higher Pitt bacteremia score (aOR, 5.15), ineradicable or not-eradicated foci (aOR, 4.05) and combination therapy for definitive treatment (aOR, 0.35) were independent risk factors for mortality.

Conclusion
Our study suggests that carbapenemase production is not a mortality risk factor in CRE bacteremia and provides additional evidence for early source control and combination therapy.

Disclosures
All authors: No reported disclosures.
519. Multidrug-resistant Gram-Negative Bacteremia in Pediatric Patients: Is It Time to Change to Empiric Meropenem?
Authors: Mongkolrattanothai Kanokporn , Stach Leslie , Orbach Regina 
Published: October 2019

Abstract

Background
The rise of antimicrobial resistance among gram-negative (GN) pathogens has been dramatic nationally. Delayed initiation of active antimicrobial agents has been associated with poor outcomes. We aimed at evaluating the prevalence and treatment of multi-drug-resistant gram-negative (MDR-GN) bacteremia in our pediatric patients.

Methods
All episodes of GN bacteremia from 2017–2018 at our institution were retrospectively reviewed. GN defined as MDR in our study were carbapenem-resistant organisms (CRO), extended-spectrum β-lactamase (ESBL) producers, and GN that were resistant to cefepime and ≥2 classes of non-cephalosporin antimicrobial agents. Stenotrophomonas maltophilia was excluded. Ineffective empirical treatment (IET) is defined as an initial antibiotic regimen that is not active against the identified pathogen[s] based on in vitro susceptibility testing results.

Results
A total of 292 episodes of GN bacteremia were identified and 6 S. maltophilia were excluded. Of these, 29 bacteremic episodes in 26 patients were caused by MDR-GN organisms including 18 ESBL, 7 CRO, 1 ESBL and CRO, 3 non-ESBL/non-CRO cefepime-resistant MDR-GN. None of the CRO had carbapenemase genes detected. However, there was a patient with multiple sites of infection simultaneously with non-NDM CR Acinetobacter bacteremia and NDM-mediated CR-Klebsiella ventriculitis. The annual rate of MDR-GN bacteremia increased from 8% in 2017 to 12% in 2018. Almost half (48%) of episodes were community onset. Among these, all but one had underlying medical conditions with hospital exposure and most patients had central venous devices at the time of infection. 52% (15/29) episodes of MDR-GN bacteremia had IET. Despite IET, 47% (7/15) had negative blood cultures prior to initiation of effective therapy (6 ESBL and 1 P. aeruginosa). Various antibiotic regimens were used for CRO therapy as shown in Table 1.

Conclusion
In our institution, MDR-GN infection is increasing. As such, empiric meropenem is currently recommended in BMT or neutropenic patients with suspected sepsis. However, empiric meropenem must be used judiciously as its widely use will lead to more selection of MDR pathogens. It is essential to continue monitoring of these MDR-GN to guide appropriate empiric regimens.

Disclosures
All authors: No reported disclosures.
520. The Clinical Profile and Outcomes of Patients given Intravenous Colistin for Multidrug-Resistant Gram-negative Infections in a Philippine Tertiary Hospital
Authors: Li Kingbherly L , Abad Cybele Lara R 
Published: October 2019

Abstract

Background
Colistimethate sodium (colistin) is used to treat multi-drug-resistant Gram-negative infections. We describe the profile and outcomes of patients given colistin in a tertiary level government hospital.

Methods
We performed a retrospective cross-sectional study of patients from the Philippine General Hospital given intravenous colistin between January 2015 to June 2018. Adult patients who received colistin for at least 24 hours and not on dialysis were included. Clinical success was defined as a composite of hemodynamic stability, stable quick Sequential Organ Failure Assessment score (qSOFA), and microbiological cure. Overall in-hospital mortality was recorded.

Results
We included 250 patients during the study period. The median age was 55 (19–91) years, 55.6% (139/250) were male, and 49.2% (123/250) were admitted in the intensive care unit (ICU). 77.2% (193/250) had at least one comorbidity, with solid-organ malignancy (27.6%, 69/250) being the most common. Most patients had at least one invasive device, commonly a nasogastric tube (64.4%, 161/250) or mechanical ventilator (63.2%, 150/250). There was an increase in Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II score, qSOFA, and septic shock from baseline to 24 hours prior to colistin use (Table 1). The most common site of infection was the respiratory tract (90.8%, 227/250). Majority of patients (78.8%, 197/250) had Acinetobacter baumannii infection of which 79.9% were extensively drug-resistant (XDR), susceptible only to colistin and amikacin or minocycline. Colistin was given for a mean of 12 (2- 43) days, concomitant with meropenem in 96.4% (241/250). Most patients received piperacillin–tazobactam (59%, 142/250) and/or meropenem (58%, 138/250) within the same admission. Nephrotoxicity (30.8%, 77/250) was the most frequent adverse effect (Table 2). Renal replacement therapy was needed in 6% (15/250) patients. Clinical success was seen in 61.2% (153/250) patients and overall mortality was 41.6% (104/250).

Conclusion
Colistin was frequently used in combination with a carbapenem for treatment of XDR-related respiratory infection or septic shock. Nephrotoxicity was a common adverse effect. The clinical success rate was modest and overall mortality was high.

Disclosures
All authors: No reported disclosures.
534. Active Screening for Carbapenemase Producing Enterobacteriaceae: Yield and Cost Considerations
Authors: Ramos-Castaneda Jorge A , Reeme Allison , Buchan Blake W , Ledeboer Nathan A , Beth Graham Mary , Pintar Paula , Singh Siddhartha , Silvia Munoz-Price L 
Published: October 2019

Abstract

Background
During 2016, our hospital experienced an outbreak with carbapenemase-producing Enterobacteriaceae (CPE) in our solid-organ transplant (SOT) population. Since this outbreak and until now, our hospital has implemented active CPE screening of patients admitted to SOT units and point prevalence surveillances in any unit with a known CPE patient. The present study evaluates the yield of these screening tests and their cost since implementation.

Methods
This retrospective cohort was performed in a 600-bed hospital in Milwaukee, WI. CPE screening tests were retrieved from the clinical microbiology laboratory dataset from January 2016 to April 2019. CPE tests are performed on rectal swabs or stool samples using the CDC broth enrichment method followed by MIC confirmation using Etest. CPE patients were placed on enhanced precautions (gowns, gloves, booties) and were cohorted geographically and to 1:1 nursing and nurse aid staff.

Results
A total of 6,684 samples belonging to 3,383 patients were processed (1.9 samples/patient). Two hundred thirty (3.44%) had carbapenem-resistant Enterobacteriaceae, although only 33 isolates (0.49%) were confirmed as either KPC (n = 31) or NDM (n = 2) positive. Out of the 3,383 patients tested, 121 were identified as carriers of carbapenem-resistant isolates but only 11 (0.32%) were CPE (KPC = 11; NDM = 2). The incidence of new CPE patients during 2016 was 0.82% but decreased to 0.28% and 0.33% in 2017 and 2018, respectively. The units with the highest number of CPE patients were the transplant intensive care unit (n = 6) and the step-down SOT unit (n = 3). Negative cultures were quoted at $8.49 per sample but culture plates with colonies increased the cost per test to $28.44. The total cost for all the 6,684 screening tests was calculated at $61,335. The cost of CPE screening per positive CPE patient identified comes up to $5,575 (not including RN collection time).

Conclusion
In an institution with staff and CPE patient cohorting, active screening of CPE positive patients was relatively expensive given our low -level of transmission. In the near future, we plan to stop staff and patient cohorting due to the high stress that these interventions place on our hospital staff. This might ensue in increase transmission, which will be detected by CPE screening tests.

Disclosures
All authors: No reported disclosures.
542. Los Angeles County Acute Care Regional Antibiogram Suggests Changing Landscape of MDRO Threats Between 2015 and 2017
Authors: McKinnell James , Foo Chelsea , OYong Kelsey , Hindler Janet , Ceja Sandra , Bloomfield Leah , Felix-Mendez Joanna , Tchakalian Gregory , Hurtado Aura , Eliopulos Alyssa , Sinkowitz Jake , Torres Crystal , Richter Stefan , Ha David 
Published: October 2019

Abstract

Background
National surveillance for multidrug-resistant organisms (MDRO) are limited by narrow geographic sampling, few hospitals, and failure to account for local epidemiology. A Los Angeles County (LAC) regional antibiogram was created to inform public health interventions and provide a baseline for susceptibility patterns countywide. We present data to compare the 2015 and 2017 LAC regional antibiogram.

Methods
We conducted a cross-sectional survey of cumulative facility-level antibiograms from all hospitals in LAC; 83 hospitals (AH) and 9 Long-term Acute Care (LTAC). For 2015, submission was voluntary, 2017 data were collected by public health order. Non-respondents were contacted by phone and in person. Isolates from sterile sources were pooled. Countywide susceptibility was calculated by weighting each facility’s isolate count by its reported susceptibility rate with minimum–maximim observed (2015) and Interquartile range (IQR) for 2017. Change from 2015 mean susceptibility is reported.

Results
Seventy-five (75) facilities submitted antibiograms for 2015 and 86 facilities for 2017. Among non-respondents in 2017, two facilities could not provide an adequate antibiogram and 4 were specialty hospitals with too few cultures to create an antibiogram. Regional summmary tables are presented in Tables 1–4. Klebsiella pneumoniae (n = 50 hospitals/19,382 isolates) % S to meropenem was 97% (IQR 94–100%), no change from 2015. Pseudomonas aeruginosa (PA) (n = 52 hospitals/17,770 isolates)% S to meropenem was 84% (IQR 74–93%), no change from 2015. Susceptibility to Acinetobacter baumannii (AB) was reported by 48 hospitals, including 1,4361 isolates,% S to meropenem was 39% (IQR 25–75%), 14% lower than 2015. Streptococcus agalactiae (n = 13 hospitals/647 isolates)% S to clindamycin was 43% (IQR 13–59%), a 22% increase from 2015.

Conclusion
LAC regional antibiograms identified stable patterns of antimicrobial resistance for most pathogens, but concerning results with AB and PA. Analysis of highly drug-resistant pathogens such as AB and PA would be improved with patient-level data to generate a combination antibiogram. We favor presenting IQR %S as done for 2017. Ongoing analysis will include multivariable analysis of observed changed S controlling for hospital characteristics.

Disclosures
All authors: No reported disclosures.
544. Clonal Spread of Two Sequence Types of Carbapenem-Resistant Acinetobacter baumannii Blood Isolates at a Tertiary Care Hospital in South Korea Over 2.5 Years
Authors: Eun Kim Seong , Choi Su-Mi , Yu Yohan , un Shin Sung , hoon Oh Tae , Jin Kim Uh , Kang Seung-Ji , Jang Hee-Chang , Park Kyung-Hwa , In Jung Sook 
Published: October 2019

Abstract

Background
The dissemination of carbapenem-resistant Acinetobacter baumannii (CRAB) became an urgent public health concern. A specific sequence type (ST) of A. bauamannii has been reported to be associated with severity of disease or mortality. This study aimed to determine the genetic relatedness of CRAB blood isolates cultured from patients at a tertiary care hospital and to investigate clinical characteristics and outcome of CRAB bacteremia.

Methods
CRAB blood isolates were collected between June 2016 and December 2018, and their clinical data were obtained. Multi-locus sequence test (MLST) was performed using the Oxford scheme, and the STs were assigned using the MLST database.

Results
Of the 126 CRAB blood isolates, 123 isolates which could be typed by MLST all belonged to clonal complex (CC) 92. During the entire period, ST369 (42.3%) was the most dominant, followed by ST191 (32.5%), ST784 (13.8%) and ST451 (4.1%). ST369 was firstly introduced in August 2017. ST191 (61.4%) was the most abundant during June 2016 to July 2017, whereas ST369 (65.8%) replaced ST191 (16.5%) since August 2017. The time interval between intensive care unit admission and bacteremia was shorter in ST369 than ST191 in multivariate analysis (day, median (Q1, Q3), ST369 6 (3, 9.8), ST191 9 (6, 17), Odd Ratio 0.87 (95% CI 0.76–0.99) P = 0.048 logistic regression). According to the ST, the 7-day and 30-day mortality rates were as follows; 46% and 65% in ST191, 50% and 62% in ST369, and 10.7% and 46.4% in the other STs. Patients infected by ST191 or 369 had significant higher 7-day mortality rates (ST191/369, 48.3% vs. the other STs 10.7%, P = 0.001 by log-rank test) and 30-day mortality rates (ST191/369, 63.2% vs. the other STs, 46.4%, P = 0.045 by log-rank test).

Conclusion
This study demonstrates the clonal spread of two STs at a tertiary care hospital in South Korea over 2.5 years. After the introduction of ST369, it replaced ST 191 and widely disseminated within a hospital. Two predominant STs were associated with poor outcome. Continuous surveillance are necessary to monitor the dissemination of these strains.

Disclosures
All authors: No reported disclosures.