bluuebunny/crossref_metadata_2025 huggingface dataset:
429. Ocular gonorrhea infections in New York City, 2006–2017
Authors: Sfeir Maroun M , Johnson Kimberly , Klingler Ellen , Schillinger Julia
Published: October 2019

Background

Ocular gonorrhea infections (OGI) have been rarely reported in United States adults. Unlike other bacterial eye infections which may be treated with topical antibiotics, OGI is typically characterized by purulent conjunctivitis with profuse exudate and requires treatment with systemic antibiotics. Genital gonorrhea infections are increasing nationally and in New York City (NYC). New York State mandates prophylactic antibiotic treatment of newborns to prevent purulent conjunctivitis. We describe the number and characteristics of OGI case-patients diagnosed among NYC residents over a 12-year period.

Methods

We examined data from two different sources: (1) the NYC Health Department sexually transmitted infections (STI) surveillance registry (January 2006-October 2017) in which OGI cases were defined as laboratory-confirmed infection of the eye or eye appendages; and (2) a hospital discharge database (inpatient and emergency room) for NYC residents admitted to any New York State hospital (inpatient or emergency room discharges, January 2006–December 2016) in which cases of OGI were identified using diagnostic codes corresponding to OGI. We characterized de-duplicated OGI cases identified across these data sources for 2006–2017 and calculated the OGI rate/100,000 reported gonorrhea cases.

Results

Thirty-six OGI cases were identified in STI surveillance data and 55 additional cases in the hospital discharge database. Out of the total of 91 OGI cases, 20 (22%) were ≤1 year (11 males, 9 females), 3 (3.3%) were 2–14 years (all males), and 68 (74.7%) were ≥15 years old. Among the 68 adolescent/adult case-patients, the mean age was 29.04 ± 13.4 years. The majority were males (69.1%, 47/68,) and African American (42.6%, 29/68). The OGI rate in adolescents/adults was 39.95/100,000 gonorrhea cases (females, 35.76; males, 42.31); the rate remained almost constant since 2006 despite the increases in gonorrhea over the past decade. Conjunctivitis was the most common presentation (90.1% of all cases; 82/91), followed by eye appendage infections (2.2%; 2/91). The STI surveillance data revealed the diagnosis of OGI was made mainly by ocular culture (86.1%; 31/36), followed by nucleic acid amplification test (NAAT) (8.3%), or both culture and NAAT (5.6%).

Conclusion

OGI appear to be a rare disease in NYC. The majority of infections occurred among adolescents and adults, likely due to mandated newborn prophylaxis.

Disclosures

All authors: No reported disclosures.
441. Factors Associated with a Change of Antimicrobial Therapy in Patients with Cellulitis Who Started with Amoxicillin–Clavulanate (A/C) Monotherapy
Authors: Collazos Julio , De la Fuente Belén , De la Fuente Javier , Garcia Alicia , Gomez Helena , Suárez-Zarracina Tomás , Rivas-Carmenado Maria , Enriquez Hector , Sánchez Paula , Alonso María , López-Cruz Ian , Martin-Regidor Manuel , Martinez-Alonso Ana , Guerra José , Artero Arturo , Blanes Marino , Asensi Victor
Published: October 2019

Background

Cellulitis is a frequent cause of admission of adult patients to medical wards and A/C monotherapy is commonly used as the initial regimen. Studies evaluating the factors associated with the change of this regimen are lacking.

Methods

Data were extracted from a prospective and observational study of 606 adult patients with cellulitis admitted to several Spanish hospitals. Comorbidities, microbiological, clinical, lab, diagnostic, and treatment data were analyzed and compared according to the continuation/change of A/C. Multiple logistic regression modeling was performed to determine the variables independently associated with A/C switching.

Results

Overall 259 (42.7%) patients started A/C monotherapy, 56 (21.6%) of which were switched to other antimicrobials. Patients switched from A/C developed sepsis (19.6% vs. 8.4%, P = 0.02) and underwent imaging methods (P < 0.01) more commonly than those kept on A/C. These A/C switched patients had higher serum glucose (P = 0.04), creatinine (P < 0.0001), leukocyte (P = 0.006) and neutrophil counts (P < 0.0001). Regarding microbiological data, patients switched from A/C had more frequently pus (P < 0.0001) and blood cultures (P = 0.002) available, a microorganism identified (P < 0.0001) and higher rates of Gram-negative bacilli infections (P = 0.003). Patients switched from initial A/C had also longer hospitalization stays (10.5 vs. 5.2 days, P < 0.00019, longer duration of IV (10.0 vs. 4.3 days, P < 0.0001), and overall antibiotic treatment (16.5 vs. 10.4 days, P < 0.0001) and needed more frequently surgical treatment (25.0 vs. 4.9%, P < 0.0001), specialized follow-up after discharge (36.4 vs. 17.3%, P = 0.0009) and combination therapy after discharge (35.9% vs. 1.1%, P < 0.0001).The variables independently asociated with A/C switch in the multivariate analysis were higher serum creatinine (P = 0.03), neutrophil counts (P = 0.003), days on IV antibiotics (P < 0.0001) and the needed for surgical treatment (P = 0.004)

Conclusion

Patients switched from the initial A/C regimen do not have differences in the predisposing factors, but seem to have more serious cellulitis, characterized by higher neutrophil counts and serum creatinine, needing extended IV antibiotic therapy and additional surgical debridement.

Disclosures

All authors: No reported disclosures.
453. High Burden of Invasive and Severe Group A Streptococcus Disease Among Native Americans on the White Mountain Apache Tribal Lands
Authors: Sutcliffe Catherine , Close Ryan M , Davidson Anne M , Reid Angelina , Quay Dianna , Nicolet Katherine , Brown Laura B , Grant Lindsay , Weatherholtz Robert , McAuley James , Hammitt Laura
Published: October 2019

Background

Native Americans are overrepresented in outbreaks of Group A Streptococcus (GAS) in the United States (US). In 2016, several invasive cases of GAS were detected at the Whiteriver Indian Health Service (IHS) Hospital in Arizona that primarily serves the White Mountain Apache (WMA) Tribe. The objective of this study was to determine the burden of invasive and severe GAS disease among Native Americans on the WMA Tribal lands.

Methods

Prospective population and laboratory-based surveillance for invasive and severe GASinfections was conducted for two years from March 2017 through February 2019. A case was defined as a Native American individual living on or around WMA Tribal lands with GAS isolated from a normally sterile body site (invasive) or from a non-sterile site (e.g., wound, throat, ear) requiring hospitalization (severe). Incidence rates were calculated using the IHS User Population as the denominators. Age-standardized incidence rates were calculated using US Census data from 2015 as the reference group.

Results

157 cases were identified (Year 1: 85; Year 2: 72), including 42 (27%) invasive and 115 (73%) severe cases. Most cases were adults (88.5%; median age: 40.5 years) and had ≥1 underlying medical condition (99.4%), including alcoholism (57.1%), hypertension (37.2%), and diabetes (34.0%). 47.8% of cases had a trigger in the past two weeks, including penetrating trauma (31.8%) and blunt force trauma (14.0%). For 72.9% of cases, a co-infection was detected (most commonly Staphylocccus aureus: 96.8%). 4.5% of cases required amputation and 1.9% died within 30 days of initial culture. The incidence of invasive and severe GAS was 460.9 per 100,000 persons (95% confidence interval: 394.3, 538.8), with no significant difference by year. The incidence was highest among adults ≥65 and lowest among children 5–17 years of age. Age-standardized incidence rates of invasive and severe GAS and invasive only GAS are presented in the Figure.

Conclusion

The WMA community has experienced disproportionately high rates of invasive and severe GAS for over two years. Studies to determine the reservoirs for transmission are urgently needed, as are interventions to reduce the morbidity and mortality associated with these infections.

Disclosures

All authors: No reported disclosures.
456. Dalbavancin, a Long-Acting Lipoglycopeptide Antimicrobial Agent, Reduces Length of Stay and Improves Patient Work Productivity in a Hospital Critical Pathway for Acute Bacterial Skin and Skin Structure Infections (ABSSSI)—the ENHANCE ABSSSI Trial
Authors: McCarthy Matthew W , Keyloun Katelyn R , Gillard Patrick , Choi Justin J , Copp Ronald , Walsh Thomas J
Published: October 2019

Background

Prolonged admissions for acute bacterial skin and skin structure infections (ABSSSI) present an opportunity to improve efficiency and quality of care. A primary reason for admission for ABSSSI is to receive intravenous (IV) antibiotics, where multiple guidelines support shifting care to outpatient settings for appropriate patients. A hospital pathway for ABSSSI that leverages long-acting IV antibiotic therapy, such as dalbavancin, may reduce the length of stay (LOS). The ENHANCE ABSSSI trial (NCT03233438) sought to quantify LOS vs. that of usual care after implementing a new ABSSSI pathway.

Methods

A single-center, pre- vs. post-period pragmatic trial at Weill-Cornell Medical Center assessed usual care for consecutively enrolled ABSSSI patients during an observational period (pre-period). A new ABSSSI pathway was implemented in the post-period, which included (1) identification of eligible admitted ABSSSI patients and (2) treatment with dalbavancin. Those with life-threatening infections, requiring multiple antibiotics/intensive care, or with unstable comorbidities were excluded. Outcomes were assessed over a 44-day follow-up period.

Results

Of 48 and 43 patients enrolled in pre- and post-periods (Figure 1), mean infection-related LOS was reduced in the post-period (3.2 days vs. 4.8 days; P = 0.003; Figure 2 and 3). Similar results were found in an adjusted LOS analysis. Work productivity and activity impairment outcomes significantly improved in the post-period, apart from absenteeism, while quality of life was similar between periods (Figure 4). Complete response to treatment was similar between periods: 50% (pre-period) and 57% (post-period). A greater proportion of total adverse events (AEs) occurred in the post-period (n = 20; 48%) vs. pre-period (n = 3; 6%) with most AEs being mild in severity and not related to antibiotic use; few AEs were serious (7% [n = 3] post-period vs. 2% [n = 1] pre-period). The most common AEs were unrelated infection in the pre-period and fever in the post-period.

Conclusion

After implementing the ENHANCE ABSSSI pathway among eligible patients, LOS was significantly reduced by almost 2 days, with potential improvements in work productivity and the ability to complete daily activities.

Disclosures

All authors: No reported disclosures.
461. Management of ABSSSIs: An Assessment of Knowledge, Competence and Clinical Practices among ID Specialists
Authors: Hurst Simi Thomas , Maeglin John
Published: October 2019

Background

One of the most common bacterial infections overall and among the most common causes for ED referral and/or hospital admission, ABSSSIs continue to impart a significant public health burden. The rising tide of MDROs has limited the clinical utility of many traditional antibiotics and increasing age and comorbid conditions such as diabetes, impaired renal or hepatic function, and CVD disease further complicate patient management strategies, putting patients at increased risk for treatment failure.

Methods

A continuing medical education (CME)-certified clinical practice assessment comprising 25 multiple choice questions that measured ID specialists’ knowledge, competence, confidence and current practices in the management of ABSSSIs. The survey instrument was launched on a website dedicated to continuous professional development on July 27/18. Respondent confidentiality was maintained and responses were de-identified and aggregated prior to analyses.

Results

To date, 2921HCPs, including 2,380 physicians have participated in the activity. Data for ID specialists who had participated as of April 17, 2019 are presented; data collection are ongoing. The majority of ID specialists (68%; n = 268) practiced in the inpatient setting. Despite a relatively high level of confidence in several areas (Table 1 and data not shown), the data identified several knowledge and competence gaps with regard to antimicrobial agent selection, treatment duration, and management of complicated ABSSSIs (Table 2). The most frequently cited barriers to optimal care included: (i) logistical challenges in arranging for appropriate patient follow-up (33%; n = 122); (ii) knowledge about appropriate duration of antibiotic therapy (19%; n = 71); and (iii) access to more expensive antibiotic therapies that may be more effective (19%; n = 71).

Conclusion

This activity identified knowledge and competency gaps in the management of patients with ABSSSIs. These findings will be used to inform the development of educational programs that may help narrow these gaps and improve patient care.

Disclosures

All authors: No reported disclosures.
467. Antimicrobial Resistance and Molecular Analysis of Staphylococcus aureus in Staphylococcal Scalded Skin Syndrome among Children in Korea
Authors: Hong Choi Jae , Lee Hyunju , Hwa Choi Eun
Published: October 2019

Background

Staphylococcal scalded skin syndrome (SSSS) is a blistering and desquamative skin disease caused by the exfoliative toxins of Staphylococcus aureus. SSSS mainly affects children younger than 5 years of age. Although many countries show a predominance of methicillin-susceptible S. aureus (MSSA), recently an increase in cases due to methicillin-resistant S. aureus (MRSA) has been reported. We investigated the molecular characteristics of S. aureus isolated from the children with SSSS in Korea.

Methods

From January 2010 to December 2017, children clinically diagnosed as SSSS under the age of 5 years were enrolled. Cases from 3 different university hospitals in Korea were included. S. aureus isolated from nasal, axillary, or inguinal area of the children were analyzed for multilocus sequence type and exfoliative toxins (eta, etb). Medical records were retrospectively reviewed for clinical characteristics and antimicrobial susceptibility patterns of S. aureus.

Results

A total of 26 cases were enrolled. The mean age was 2.3 years (range, 0–4.8 years). Twenty-two (84.6%) patients were hospitalized. Skin manifestations were classified as follows; generalized (n = 10, 38.5%), intermediate (n = 11, 42.3%), and abortive (n = 5, 19.2%). Twenty-five isolates (96.2%) were resistant to methicillin and macrolide-resistance was found in 92.3% (n = 24). ST89 (n = 21, 80.8%) was the most prevalent clone, with single clones of ST1, ST5, ST72, ST121, and ST1507. The eta gene was detected in 1 (3.8%) MSSA isolate. The etb gene was detected in 14 (53.8%) isolates all of which were ST89. All patients were treated with antibiotics, and the mean duration was 8.3 days regardless of the administration route. Nafcillin or first cephalosporin was most commonly prescribed (n = 20, 76.9%), clindamycin was administered in combination in 9 patients (34.6%) and vancomycin in 4 patients (15.4%). Among the 25 MRSA cases, only 6 (24.0%) were treated with susceptible antibiotics. However, there was no difference in treatment duration according to antimicrobial susceptibility (8.43:8.22 days, P > 0.05).

Conclusion

The molecular epidemiology of S. aureus isolated from the Korean children with SSSS demonstrated the high prevalence of methicillin-resistant ST89 clone that harbors the etb gene.

Disclosures

All authors: No reported disclosures.
480. Molecular Characterization of Multidrug-Resistant Gram-Negative Pathogens in Three Tertiary Care Hospitals in Egypt
Authors: Kholy Amani , Girgis Samia A , Elmanakhly Arwa R , Shetta Mervat A F , El- Kholy Dalia , Zahran Mariam
Published: October 2019

Background

High rates of AMR among Gram-negative bacilli (GNB) have been reported from Egypt for almost 2 decades. Surveillance and identifying the genetic basis of AMR provide important information to optimize patient care. As there is no adequate data on the genetic basis of AMR in Egypt, we aimed to identify the molecular characterization of multi-drug-resistant (MDR) Gram-negative pathogens (GNP).

Methods

Three major tertiary-care hospitals in Egypt participated in the “Study for Monitoring Antimicrobial Resistance Trends” (SMART) from 2014 to 2016. Consecutive GNPs were identified and their susceptibility to antimicrobials were tested. Molecular identification of ESBL, AmpC, and carbapenemase resistance genes was conducted on MDR isolates.

Results

We enrolled 1,070 consecutive Gram-negative isolates; only one isolate per patient according to the standard protocol of (SMART). During 2014–2015, 578 GNP were studied. Enterobacteriaceae comprised 66% of the total isolates. K. pneumoniae and E. coli were the most common (29.8% and 29.4%). K. pneumoniae and E. coli were the predominant organisms in IAI (30.5% and 30.1%, respectively) and UTI (and 38.9% and 48.6%, respectively), while Acinetobacter baumannii was the most prevalent in RTI (40.2%). ESBL producers were phenotypically detected in 53% of K. pneumoniae, and 68% of E. coli. During 2016, 495 GNP were studied. ESBL continued to be high. For E. coli and K. pneunomiea, the most active antimicrobials were amikacin (≥93%), imipenem/meropenem (≥87%) and colistin (97%). Genetic study of ertapenem-resistant isolates and 50% of isolates with ESBL phenotype revealed ESβL production in more than 90% of isolates; blaCTXM-15 was detected in 71.4% and 68.5% in K. pneumoniae and E. coli, respectively, blaTEM-OSBL in 48.5% and47.5% of K. pneumoniae and E. coli, respectively. Carbapenem resistance genes were detected in 45.4% of isolates. In K. pneumoniae, OXA-48 dominated (40.6%), followed by NDM1 (23.7%) and OXA-232 (4.5%).

Conclusion

Our study detected alarming rates of resistance and identified many resistance mechanisms in clinical isolates from Egyptian hospitals. These high rates highlight the importance of continuous monitoring of the resistance trend and discovering the novel resistant mechanisms of resistance, and the underscores a national antimicrobial stewardship plan in Egypt.

Disclosures

All authors: No reported disclosures.
496. Carbapenem-resistant Enterobacter: A Case-Case–Control Investigation
Authors: Cohen Mendel Leore , Katz David , Lazarovitch Tsilia , Zaidenstein Ronit , Marchaim Dror
Published: October 2019

Background. Background

The World Health Organization has declared carbapenem-resistant Enterobacteriaceae (CRE) as a worldwide public health threat. Analyzing the epidemiology of CRE was derived from cohorts consisting primarily of Klebsiella pneumoniae isolates. The second most frequent CRE is Enterobacter (CREn), but its molecular and clinical epidemiology differ from that of K. pneumoniae, and it has not been analyzed while implementing updated methodological tools and design.

Methods

A matched case-case–control investigation was conducted at Shamir (Assaf Harofeh) Medical Center, Israel, for calendar years 2007–2017. Each CREn case was matched to a carbapenem-susceptible Enterobacter (CSEn) case and to an uninfected control (1:1:1 ratio). Logistic and Cox regression-matched analyses were conducted in order to study predictors and outcomes of CREn colonization and/or infection, respectively.

Results

The study included 216 cases (72 in each group). Numerous predictors were significantly associated with CREn as per bivariable analyses, but the only independent significant predictors were: (1) recent (3 months) exposure to fluoroquinolones (aOR=2.94, P = 0.04), (2) intensive care unit stay in current hospitalization prior to culture (aOR=3.56, P = 0.003), and (3) a rapidly fatal McCabe score (aOR=0.471, P = 0.01). Patients with CREn suffered from significant delays in instituting appropriate antimicrobials (P = 0.03), and for those who survived the hospitalization, were more frequently discharged to a long-term care facility after being admitted to the index hospitalization from home (aOR=3.3, P = 0.02).

Conclusion

This case-case–control-matched investigation of CREn epidemiology, revealed a unique modifiable predictor, i.e., recent fluoroquinolone exposure, which could represent a target for stewardship intervention. The case-case–control-matched design allowed for the control of numerous confounders previously reported to be associated with CREn but may represent a risk factor for Enterobacter infection in general. As with other CRE, CREn carriers suffer from significant delays in initiation of appropriate antimicrobials and from worse outcomes.

Disclosures

All authors: No reported disclosures.
500. Prevalence of Extended-Spectrum β-lactamase and Carbapenem-Resistant Gram-Negative Bacteria in Patients with Urinary Tract Infection and Urosepsis Admitted through Emergency Departments in the United States
Authors: Takhar Sukhjit , Krishnadasan Anusha , Moran Gregory J , Mower William , Pathmarajah Kavitha , Gonzalez Eva , Vargas Julia , Talan David A
Published: October 2019

Background

Gram-negative infections due to extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, and carbapenem-resistant Enterobacteriaceae (CRE) and non-fermenting (CR-NF) strains, are increasingly encountered. Study objectives were to determine prevalence and associated risk factors and outcomes for these strains among emergency department patients hospitalized for urinary tract infection (UTI) at 11 US hospitals.

Methods

This was a prospective observational study of patients ≥18 years hospitalized for UTI. Clinical data were collected at the index visit. Urine was obtained for culture and susceptibility testing. Electronic medical record and telephone follow-up were conducted after 30 days for site laboratory results, treatment, and clinical outcomes. Positive culture was defined as 1 uropathogen with growth at ≥104 cfu/mL, or 2 with 1 or both at ≥105 cfu/mL, or ≥3 with 1 or 2 at ≥105 cfu/mL. Isolates with ceftriaxone (CRO) or meropenem MIC >1 μg/mL will undergo reference laboratory (IHMA, Inc., Schaumburg, IL) susceptibility testing, including against newer antibiotics and cefiderocol.

Results

We enrolled 774 participants between 2018 and 2019; 289 (37.3%) excluded due to urine culture not done, no growth, or contamination. Of 485 culture-positive participants (median age 56 years, 62.0% female), 432 (89.1%) grew 1 uropathogen, 48 (9.9%) 2, and 5 (1.0%) ≥3. Prevalences of CRO-resistant Enterobacteriaceae, CRE, and CR-NF were 19.9%, 2.1%, and 10.7%, respectively. At sites, 95.7% of CRO-resistant Enterobacteriaceae isolates were ESBL. Among participants with any or no antibiotic resistance risk factors, i.e., antibiotics, hospitalization, long-term care, or travel within 90 days, prevalence of CRO-resistant Enterobacteriaceae was 68/228 (29.8%) and 10/155 (6.5%), respectively. Among those with CRO-resistant vs. susceptible Enterobacteriaceae infections, ICU admission and death occurred in 9.9% vs. 6.6% and 3.7% vs. 1.0%, with median time home over 30 days, 24 vs. 27 days, respectively.

Conclusion

Among US hospitalized patients with UTI, infections due to CRE remain uncommon; however, ESBL and CR-NF now account for a substantial proportion of cases and are associated with resistance risk factors and worse outcomes.

Disclosures

All authors: No reported disclosures.
511. MDRO Carriage in Patients in Two ICUs and Prevalence of Environmental Surface and Healthcare Worker Hand Contamination
Authors: Tanner Windy , Coombs Jana , Fernley Tasha , Danala Suresh , Lopansri Bert K , Rubin Michael
Published: October 2019

Background

Determining MDRO (multidrug-resistant organism) transmission routes in intensive care units (ICUs) can be complex and require the evaluation of multiple potential MDRO sources, including patients, the environment, and healthcare worker (HCW) hands. The objective of this study was to determine MDRO carriage in patients in two separate ICUs, and simultaneous environmental and HCW hand contamination from associated rooms.

Methods

Patient (P), environmental (E), and HCW hand (H) samples were collected from hospital A (1183 H, 1253 E, 729 P) and hospital B (699 H, 1372 E, 437 P) over approximately 5 weeks in each unit. Environmental and HCW hand samples were collected using a cellulose sponge. HCW hand samples were collected prior to any hand hygiene. Patient samples were collected from the axilla, groin, and perianal areas with a flocked swab with patient consent. All samples were tested semi-quantitatively for Clostridium difficile (Cdiff), vancomycin-resistant enterococci (VRE), and cefotaxime-resistant Enterobacteriaceae (Cef-R-Ent) by selective culture. Cdiff isolates representative of each P/E/H cluster were tested for Cdiff toxin testing by PCR.

Results

Cdiff, VRE, and Cef-R-Ent were detected in patients, patient rooms, and on HCW hands in both facilities (Table 1). Cdiff was more prevalent in Facility A, while Cef-R-Ent was more prevalent in Facility B. The prevalence of VRE was minimal in both facilities. Cdiff toxin gene testing revealed that 17% of the Cdiff isolate clusters tested positive for toxin genes. In Facility A, the prevalence of a given MDRO was similar regardless of sample type, but was more widely varied between sample types in Facility B. Prevalence of MDROs on HCW hands and in the environment was typically higher in Facility A compared with Facility B. Individual patient positives were frequently linked to positive HCW hand and environmental cultures.

Conclusion

We discovered a low prevalence of all MDROs in both facilities, with most positive cultures associated with patients who were not on MDRO precautions. HCW hand and environmental MDRO prevalence was generally similar for each MDRO, regardless of patient prevalence, supporting previously reported links on HCW hand contamination and hospital room surfaces.

Disclosures

All authors: No reported disclosures.
532. Can Saccharomyces boulardii Therapy Be Effective in Decolonizing Rectal Carbapenem-Resistant Enterobacteriaceae (CRE) Colonization?
Authors: Resat Sipahi Oguz , Quliyeva Gunel , Cilli Feriha , Deniz Kucukler Nilgun , Dikis Demet , Bilgili-Korkmaz Nilay , Barik-Aksit Sukran , Kepeli Nurhayat , Arda Bilgin , Ulusoy Sercan
Published: October 2019

Background

CRE are globally important pathogens associated with significant morbidity and mortality. The problem of carrying CRE may continue to create a problem in discharged cases in the community. Saccharomyces boulardii sachet therapy (SBST) is reported to cause decolonization in several MDR bacteria carriers. Herein, it is aimed to present the decolonizing rates of rectal CRE colonized cases after SBST treatment.

Methods

The study period was August 2018–March 2019. Inclusion criteria were: (i) age >18, (ii) receiving Saccharomyces boulardii 250 mg sachets q12h for 7 days, (iii) being proven CRE carrier on rectal swab culture (RSC) up to 5 days period before SBST. The first repeated RSC was performed 3–5 days after the end of SBST. Data were retrieved from the hospital electronic database. Cases with three consecutive weekly performed negative RSC were considered to be decolonized. RSC were processed according to CDC protocol; briefly, the swab was inoculated into 10 mL of trypticase soy broth (bioMérieux Inc., Marcy-l’Étoile, France) with the addition of one 10-μg ertapenem disk (Oxoid, Altrincham, UK) and incubated at 35°C for 18–20 h. The next day, after vortexing, 100 μL of the inoculum was subcultured (8) onto chromID CARBA agar plates (bioMérieux) and incubated at 35°C for 18–20 h. Suspected CRE colonies on chromID CARBA (blue/green to blue/gray in color) were identified by the VITEK MS system (bioMérieux). Susceptibility testing of the isolates was performed with the VITEK 2 system (bioMérieux). Isolates were tested for their resistance phenotypes to imipenem, ertapenem, and meropenem by E-test (bioMérieux). The results were interpreted according to the EUCAST criteria.

Results

Fifteen cases [2 women, mean age 60.6 ± 18.3 (min. 18–max. 83)] fulfilled the inclusion criteria. All had a history of carbapenem usage. Five cases (33%) had three consequent negative RSC after SBST and were considered to be decolonized. Twelve cases were receiving concomitant antibiotic during SBST (10 carbapenem based regimens). Three cases who received no concomitant antibiotic were decolonized.

Conclusion

SBST may be a promising tool for decolonizing CRE carriers. These data need to be validated in larger cohorts preferably via randomized-controlled trials.

Disclosures

All authors: No reported disclosures.
533. Impact of Different Definitions on Reported Rates of Carbapenem-Resistant Enterobacteriaceae (CRE)
Authors: Passaretti Catherine , Neelakanta Anupama , Layell Jessica , Campbell Eileen , Kester Shelley
Published: October 2019

Background

Different definitions exist for tracking and trending rates of hospital-acquired Carbapenem-resistant Enterobacteriaceae (CRE). National Health Safety Network (NHSN) allows for Laboratory Identified Event (LabID) and Healthcare-associated infection (HAI) surveillance reporting for CRE. Our facility developed an internal definition for CRE prior to release of the NHSN modules that differs from the CDC definitions in that patients colonized or infected with CRE identified on hospital day 1 or 2 who had a hospitalization within the past four weeks are considered community-onset healthcare facility acquired (COHCFA) and are included in our HA definition. In addition, by our definition once a patient develops CRE any subsequent positive cultures for the same organism are not considered new events.

Methods

All CRE cultures at our facility were reviewed by an infection preventionist and hospital epidemiologist who categorized each culture as hospital acquired by our internal HA definition, NHSN LabID definition and NHSN HAI definition. Results from each method of surveillance were compiled and compared as were trends of HA CRE over time by each definition.

Results

590 patients with 975 clinical cultures for Carbapenem-resistant Klebsiella spp., Enterobacter spp and E. coli were reviewed from January 2012 to March 2019. 297 cultures met our internal definition for HA CRE compared with 302 by NHSN LabID and 189 by NHSN HAI surveillance. Sixty-one (21%) of HA cases by our definition were COHCFA. 259 patients had multiple CRE cultures and 1 patient had 22 cultures with the same CRE organism between 2014 and 2019 and met for 5 lab ID events and 5 NHSN HAI events. All 3 tests agreed that a culture was HA in 140 instances (14%) and all 3 agreed that a culture was not HA in 589 instances (60%). At least one definition yielded a discordant result in 246 cultures (25%). Trends over time were compared between the definitions. While the number of HA cases varied based on the definition used, overall trends over time were similar regardless of the definition utilized. (Figure 2)

Conclusion

Regardless of the definition used for surveillance of CRE, trends over time are similar. Consideration should be given to monitoring COHCFA cases in addition to those acquired on or after hospital day 3.

Disclosures

All authors: No reported disclosures.
582. Impact of Central Line Bundle for Prevention of Umbilical Vein Catheter-Related Bloodstream Infections in a Neonatal Intensive Care Unit
Authors: devrim İlker , Kulalı Ferit , Çağlar İlknur , Oruc Yeliz , Demiray Nevbahar , Dursun Vecihe , Gulfidan Gamze , Bayram Nuri , çalkavur şebnem
Published: October 2019

Background

Umbilical vein catheters (UVC) are one of the most common types of vascular access device in the neonatal intensive care units. Central line-associated bloodstream infections were reported to be in the first place of healthcare-associated infections in preterm infants. In this study, we aimed to evaluate the effectiveness of the bundle applications in the prevention of umbilical vein catheter-associated bloodstream infections in neonates including premature infants.

Methods

This 40 months cross-sectional study included two periods, including pre-bundle period (from August 1, 2015 to March 31, 2017) and bundle period (April 1, 2017 to November 30, 2018). The umbilical vein catheter-related bloodstream infections, catheter line days, number of the patients were recorded and compared between the prebundle and bundle periods. Bundle steps were defined as education-training-assignment, evaluation of daily catheter indications, hand hygiene and aseptic technique while insertion, maximal sterile barrier precautions, closure of the catheter area with transparent semi-permeable membrane, using needless connectors in stead of 3-way stop-cocks, and single-use prefilled saline syringes for flushing.

Results

During the whole study period total umbilical vein catheter days were 2,228 days. During the prebundle period there was 10 and in the bundle period there was 2 umbilical vein catheter-related bloodstream infections (Table 1). While umbilical vein-associated bloodstream infection rate was 8.9 per 1,000 catheter days in the pre-bundle period, and significantly decreased to 1.79 in the bundle period (P < 0.05). After the introduction of bundle applications, it was observed that the rate of infection decreased by 68% (P < 0.05)

Conclusion

Our study showed that implementation of central line bundle including needless connectors and single-use prefilled syringes for umbilical vein-related bloodstream infections was effective for the prevention of catheter-related bloodstream infections in neonatal intensive care units.

Disclosures

All authors: No reported disclosures.
600. β-Lactam Resistance Mechanisms in Pseudomonas aeruginosa Isolates Analyzed Using Whole-Genome Sequencing (WGS) and Transcriptions Analysis and Their Impact in Resistance to New β-Lactam/β-Lactamase Inhibitors
Authors: Castanheira Mariana , Doyle Timothy B , Hubler Cory , Healy Matthew , Smith Caitlin J , Mendes Rodrigo E
Published: October 2019

Background

Ceftazidime–avibactam (CAZ-AVI) and ceftolozane-tazobactam (C-T) display excellent antipseudomonal activity, but Pseudomonas aeruginosa (PSA) susceptibility against these agents can be affected by acquired resistance genes and mutations. We evaluated resistance mechanisms against these agents among 109 PSA isolates using WGS and messenger (m)RNA-sequencing.

Methods

PSA clinical isolates from Europe (n = 62), Asia-Pacific (n = 22), and Latin America (n = 25) in 2017 were susceptibility tested using reference methods and 109 were randomly selected for WGS and total mRNA-sequencing. Data were analyzed using custom software and logistic regression.

Results

Isolates carrying metallo-β-lactamases (MBLs) (n = 24) were resistant to all β-lactams, including CAZ-AVI and C-T. The only compound inhibiting >50% of the isolates was colistin. ESBL genes (blaVEB-1 or blaVEB-9), some oxacillinases, and PDC variants caused resistance to CAZ-AVI and C-T, but the presence of blaPER-1, blaGES-6, and PDC-97 led to resistance to C-T, but not to CAZ-AVI. Disruptions of ampR (PDC regulator) and glnD (nitrogen metabolism) were associated with resistance to CAZ-AVI and C-T, but armZ (anti-repressor of mexZ) disruption was only associated with C-T resistance. The combination of wild-type sequences of various genes was negatively associated with resistance to CAZ-AVI and C-T, but alterations in dnaJ (chaperone) and oprM were only related to C-T resistance. mRNA-sequencing data did not show strong correlations with CAZ-AVI or C-T resistance or with expression of genes involved in β-lactam resistance, but further analyses will expand the genes analyzed. Interestingly, among 14 isolates overexpressing MexAB-OprM that extrude CAZ, only 6 had CAZ-AVI MICs >8 mg/L.

Conclusion

Resistance mechanisms against CAZ-AVI and C-T remain poorly understood beyond MBL acquisition. In this study, resistance mechanisms statistically associated with CAZ-AVI resistance in PSA were noted among C-T-resistant isolates, but some mechanisms were only observed among C-T-resistant isolates. The richness of results employing these 2 methodologies requires further investigations that are being performed to evaluate sequences and expression alterations.

Disclosures

All authors: No reported disclosures.
624. Molecular Characterization of Baseline Enterobacteriaceae and Pseudomonas aeruginosa from a Phase 3 Nosocomial Pneumonia (ASPECT-NP) Clinical Trial
Authors: Castanheira Mariana , Johnson Matthew G , Yu Brian , Huntington Jennifer A , Carmelitano Patricia , Bruno Christopher , Rhee Elizabeth G , Motyl Mary
Published: October 2019

Background

ASPECT-NP, a phase 3, randomized, double-blind, multicenter trial, evaluated ceftolozane/tazobactam (C/T) 3 g q8h vs. meropenem 1 g q8h for 8–14 days in adults for treatment of ventilated nosocomial pneumonia. Baseline Gram-negative (GN) isolates from patients were tested for mechanisms of resistance.

Methods

Lower respiratory tract (LRT) isolates were sent to a central laboratory for organism identification and susceptibility. Of 664 total Enterobacteriaceae (ENT) and Pseudomonas aeruginosa (PsA) isolates, 351 (53%) were nonsusceptible to broad-spectrum cephalosporins and/or carbapenems and underwent whole-genome sequencing, quantitative RT–PCR, and western blot analysis. ENT isolates were tested for the presence of acquired β-lactamase genes and AmpC levels (selected species). PsA isolates were tested for acquired β-lactamase genes, AmpC (PDC) levels, efflux pump expression, and OprD loss.

Results

Of 262 ENT isolates, 114 (44%) were susceptible to C/T (MIC ≤2 µg/mL). An extended-spectrum β-lactamase (ESBL) gene was carried by 89 (78%) of the C/T-susceptible isolates. Of 148 C/T-nonsusceptible (C/T-NS) isolates, 87 (59%) were carbapenemase negative, and the majority 135 (91%) also carried an ESBL gene. The most common ESBL was blaCTX-M15 with blaOXA-1 and blaOXA-30. Klebsiella pneumoniae often displayed higher C/T MICs compared with other species carrying the same resistance genes. Among all C/T-NS isolates, 61 (41%) were carbapenemase positive, most commonly K. pneumoniae carrying blaOXA-48, blaNDM-1, and blaNDM-5. Of 89 PsA isolates, 58 (65%) were susceptible to C/T (MIC ≤4 µg/mL), despite elevated AmpC expression, efflux pumps, or loss of OprD; only 5 isolates had an acquired β-lactamase. Of the 31 C/T-NS PsA isolates, only 12 (39%) were carbapenemase positive and carried blaVIM or blaGES; isolates carrying blaGES had lower C/T MICs (8–32 µg/mL) compared with blaVIM (MIC > 128 µg/mL). PDC alleles were similar in isolates with high and low C/T MICs.

Conclusion

In baseline GN LRT isolates from ASPECT-NP, the most common ESBL detected in ENT was blaCTX-M15; carbapenemases were uncommon. There was no correlation of ESBL phenotype to C/T susceptibility among ENT, nor of PDC allele to C/T susceptibility among PsA.

Disclosures

All authors: No reported disclosures.
643. Comparison of Multiplex Polymerase Chain Reaction (PCR) and Routine Culture for the Detection of Respiratory Pathogens in Pneumonia Patients
Authors: Abu Sitta Emad , Hubbard Nicole , Suleyman Geehan
Published: October 2019

Background

The identification of causative pathogens in pneumonia can be challenging, and conventional culture methods can take up to 72 hours. However, rapid microbiologic tests identify organisms within hours. The Biofire®Filmarray ((bioMérieux, North Carolina) Pneumonia Panel was recently approved by the FDA. The multiplex PCR system identifies 33 targets from sputum and bronchoalveolar (BAL) samples, which include 18 bacteria, 8 viruses, and 7 antibiotic resistance genes. The purpose is to compare the panel to routine culture methods for the detection of respiratory pathogens in patients with pneumonia in a 794-bed teaching hospital in northwest Ohio.

Methods

We retrospectively screened all hospitalized intensive care unit patients who met clinical and radiological criteria of pneumonia using electronic medical records between November 2018 and February 2019. Adult patients who had respiratory cultures collected within 7 days were included. Repeat specimens were excluded. Routine cultures were performed using the laboratory’s standard procedure, and Pneumonia Panel testing was performed according to manufacturer instructions.

Results

Fifty-nine respiratory or 13 BAL and 46 sputum specimens were evaluated. There was no discrepancy between culture and PCR in 63% (37/59) samples. One (8%) BAL and 10 (22%) sputum specimens had additional pathogens detected by PCR. There was a discrepancy between culture and PCR in four (31%) BAL and seven (15%) sputum samples. The largest discrepancy was noted amongst Serratia marcescens (4/59 or 7%) and Haemophilus influenzae (6/59 or 10%) species. Only one sputum culture had Legionella detected by PCR. Additionally, 17 specimens had a virus detected either alone or with another bacterial pathogen by PCR. For the resistance genes, KPC was detected by PCR but not by Modified Carbapenem Inactivation Method (mCIM) test. The mecA gene was detected in six of seven (86%) of methicillin-resistant Staphylococcus aureus (MRSA) isolates. CTX-M was detected in Serratia and Klebsiella pneunomiae in two samples; however, the organisms were not isolated in culture.

Conclusion

The Pneumonia Panel can identify additional bacteria that did not grow in culture. This panel can rapidly identify pathogens and potentially reduce unnecessary antibiotic use.

Disclosures

All authors: No reported disclosures
653. Diagnosis of Burn Sepsis Using the FcMBL ELISA: A Pilot Study in Critically Ill Burn Patients
Authors: Akers Kevin S , Schlotman Taylor , Mangum Lee C , Garcia Gerardo , Wagner Amanda , Seiler Benjamin , Cartwright Mark , Rifai Sami , Ingber Donald , Super Michael
Published: October 2019

Background

Infection is the leading cause of death among burn survivors, with sepsis associated with more extensive burns. Conventional diagnostic criteria are insensitive in this population. We examined a novel diagnostic ELISA based on Mannose-Binding Lectin (MBL) linked to an immunoglobulin Fc domain, which measures the concentration of Pathogen-Associated Molecular Patterns (PAMPs) across a broad range of bacterial and fungal organisms, for diagnosis and antimicrobial management of sepsis in burn patients.

Methods

We prospectively enrolled burn patients with ≥15% Total Body Surface Area (TBSA) burns into groups of noninfected, sepsis, or incipient infection, and healthy volunteers. Sepsis was defined by clinical actions responsive to sepsis. The FcMBL ELISA was performed daily using fresh whole blood. Burn subjects were sampled daily until completing antimicrobials, for 14 days if noninfected, and once for healthy controls. Differences in median PAMP concentrations between groups were assessed with the Kruskal–Wallis test, including multiple comparisons between categories.

Results

14 burn patients (3 noninfected, of whom 1 died prior to sampling, 4 Sepsis, 7 Incipient) were enrolled. The median (25–75% CI) PAMP concentration was 0.53 (0.12–1.34) ng/mL in healthy controls, 3.725 (2.53–5.94) ng/mL in noninfected, 2.22 (1.42–4.62) ng/mL in incipient, and 1.59 (0.83–2.29) ng/mL in sepsis groups. PAMP concentrations in sepsis were different (P = 0.0057) from noninfected, but incipient did not differ from noninfected (P = 0.2025). The dynamic range was lower in healthy controls (2.69 ng/mL) than incipient (4.57 ng/mL), sepsis (4.70 ng/mL), or noninfected (5.90 ng/mL). PAMP elevations correlated with clinical deterioration from infection, and were not associated with OR visits for debridement and grafting. 7 of 11 infected patients had declining PAMP levels at completion of antimicrobial therapy. 2 subjects had PAMP elevations associated with Aspergillus molds in their burn wounds.

Conclusion

The FcMBL ELISA assay may be useful for diagnosis of infection in burn patients, and may facilitate earlier discontinuation of antimicrobials. This assay may also have a novel utility for early diagnosis of Invasive Fungal Infection.

Disclosures

All authors: No reported disclosures.
656. Prioritizing Gram-Negative Bacteremia (GNB) Cases for Rapid Detection by β-Lactam Resistance (BLR) and Patient Outcomes
Authors: McCreary Erin K , Clarke Lloyd , Marini Rachel V , Nguyen Minh-Hong , Clancy Cornelius J , Shields Ryan K
Published: October 2019

Background

GNB is associated with significant morbidity and mortality. The availability of rapid diagnostic tests (RDTs) provides an opportunity to improve outcomes. Our goal was to review GNB and its empiric treatment at our center in order to devise rational approaches to diagnostic stewardship and use of RDTs.

Methods

All patients with GNB from 2010 to 2018 were evaluated. BLR was defined by 2019 CLSI breakpoints; phenotypes are shown in Table 1.

Results

A total of 2795 GNB cases were included (Table 2); 57% occurred within the first 24 hours of hospitalization and 29.3% in the ICU. The median length of stay (LOS) was 12 days; 17.2% of patients were re-admitted within 30 days. Fourteen- and 30-day mortality rates were 13.7% and 19.5%, respectively. Rates of death were higher (30 days; 26.3% vs. 17.1%; P < 0.001) and median LOS longer (17 vs. 11 days; P < 0.001) among patients with BLR compared with susceptible GNB. Thirty-day mortality rates were highest for CRE (30.1%) and BLR P. aeruginosa (BLR-Pa; 32.8%, Figure 1). 47.7% of BLR GNB were non-CRE/ESBL, which demonstrated higher mortality rates than CRE/ESBL (30 days; 27.6% vs. 21.2%; P = 0.048). Most common empiric regimens prescribed were piperacillin–tazobactam (TZP; 50.3%), cefepime (FEP; 24.2%), carbapenem (9.3%), or other agents (16.2%). 21.6% of GNB patients received inactive empiric treatment (IET). Empiric TZP (21.9%) was more likely to be inactive than FEP (17.5%; P = 0.05), but not a carbapenem (20.7%; P = NS). 57.6% of patients with inhibitor-resistant Enterobacteriaceae (IRE) received TZP empirically. Receipt of IET was associated with higher rates of death (30 days; 22.5% vs. 16.7, P = 0.03) and longer LOS (14 vs. 11 days; P < 0.001) than receipt of active ET. Rates of IET varied by pathogen (Figure 1).

Conclusion

IET is common against BLR GNB and associated with poor pt outcomes, highlighting the potential for RDTs and diagnostic stewardship teams (DSTs) to improve care. Genotypic RDTs detect most CRE/ESBL, but may miss nearly 50% of BLR GNB cases at our center. BLR-Pa and IRE are pathogens associated with prolonged LOS, and high rates of IET and death. These pathogens could be detected earlier by phenotypic RDTs and prioritized by DSTs to optimize early treatment regimens.

Disclosures

All authors: No reported disclosures.