bluuebunny/crossref_metadata_2025 huggingface dataset:
The Expression of hsp-miRNA-200b-3p and -200c-3p in Human Cytomegalovirus-infected Formalin-Fixed, Paraffin-Embedded Tissues
Authors: Lee Kyoung Hwa , Min Seoyeon , Yoo Seul Gi , Lim Beom Jin , Jo Jeong-Hyeon , Han Sang Hoon , Song Young Goo
Published: October 2017

Background

Human cytomegalovirus (HCMV), which exist as asymptomatic latent status, can cause the tissue invasive disease through reactivation in various immunocompromised conditions. Hsp-microRNA has a specific function of post transcriptional suppression through binding with 3’ untranslated region (UTR) of mRNA. In previous study, hsp-miR-200b-3p and -200c-3p had high probability of conjugation with 3’UTR of mRNA encoded by HCMV UL 122–123 region, which translate the immediate early protein 2 (IE2) protein. IE2 (pp86) plays an essential role to initiate and regulate viral early (E) gene activation as well as propagate the subsequent steps of HCMV lytic replication. This study was aimed to evaluate whether HCMV-infected tissue had a lower expression level of hsp-miR-200b-3p and -200c-3p.

Methods

We had collected the formalin-fixed, paraffin-embedded tissues (FFPEs) with cytopathic pathologic findings as well as positive immunohistochemical stain (IHC) test for HCMV (N = 111). The HCMV-uninfected normal tissues (N = 77) were selected among FFPEs with neither infection nor inflammation as well as negative HCMV IHC test. We performed TaqMan® MicroRNA real-time RT-PCR to measure the expression levels of hsp-miR-200b-3p and -200c-3p and TaqMan® real-time PCR for HCMV UL83 region to measure HCMV viral load in each FFPE. We utilized the standard curves consisting of mirVanaTM miRNA mimics corresponding to each of two miRNAs, ranging from 106 to 101 copies/µL and HCMV NIBSC 09/162 strain, ranging from 5 X 106 to 5 X 101 IU/mL.

Results

The levels of hsp-miR-200b-3p and -200c-3p were strongly correlated with r=0.844 (P < 0.001). The expressions levels of hsp-miR-200b-3p in HCMV-infected FFPEs (log10 3.50 ± 0.13 copies/µL) were significantly lower than normal tissues (log10 5.24 ± 0.12 copies/µL of input RNA, P < 0.001). Also, HCMV-infected FFPEs were significantly lower levels of hsp-miR-200c-3p compared than normal tissues (log10 5.28 ± 0.18 vs. 7.81 ± 0.11 copies/µL of input RNA, P = 0.025). The levels of miR-200b-3p and -200c-3p had the significant inverse correlation with HCMV VL (200b-3p, spearman r=-0.392, P < 0.001 and 200c-3p, spearman r=-0.355, P < 0.001).

Conclusion

The low expression of hsp-miRNA-200b-3p and -200c-3p could play a pathophysiologic role of development of HCMV tissue-invasive disease.

Disclosures

All authors: No reported disclosures.
Human Adenovirus (HAdV) Viremia in Immunocompetent Children with HAdV Infection in Respiratory Specimens: Does Viremia Predict Severity of Illness?
Authors: Song Eunkyung , Wang Huanyu , Leber Amy , Jaggi Preeti
Published: October 2017

Background

The interpretation of HAdV PCR from upper respiratory tract (RT) specimens can be challenging due to prolonged low grade viral shedding. We hypothesized that HAdV detection in the blood (viremia) is more common in acute HAdV infection with high respiratory viral burden (VB) compared with those with low VB in the RT. We sought to determine the frequency of HAdV viremia in immunocompetent children who have detectable HAdV in the RT.

Methods

We prospectively identified + HAdV in RT specimens from emergency department or inpatients using semi-quantitative real-time PCR (Ct <40) or multiplex respiratory viral PCR (FILMARRAY RESPIRATORY PANEL v1.7) and prospectively collected available whole blood from 8/2013 to 2/2015. Blood was considered positive for HAdV if Ct was <40 in whole blood. We compared virologic, including HAdV type from the RT and blood, and clinical characteristics between viremic and non-viremic groups using Mann–Whitney or chi-square as appropriate.

Results

There were 196 unique patients with + HAdV in RT specimens as well as available blood for PCR (median age=1.3 years old). Blood and RT samples were obtained on the same calendar day in 78% of patients. Among these 196 patients, 163 (83%) were hospitalized and 58 (36%) were admitted to PICU. HAdV was detected in the blood in 33% of patients. Upper respiratory tract infections were more common (P = 0.026) and the duration of fever at the time of enrollment was longer in the viremia group (3 vs. 2 days, P = 0.043). There was no difference in ICU admission between two groups. Coinfections with bacterial pathogens from sterile sites were only found in the non-viremic group (4%); these included S. aureus or pneumococcal bacteremia, E. coli urinary tract infections, or pneumococcal pneumonia. HAdV VB in RT were significantly higher in the viremia group (Ct median 25.01 vs.. 36.38, P < 0.0001). Species C was more predominant in the viremia group compared with non C (A, B/E, D, F) (P = 0.018). RT type was 100% concordant with blood type.

Conclusion

HAdV viremia is relatively common in immunocompetent children with HAdV infection in the RT. Subjects with viremia had significantly higher VB in the RT, but this didn’t seem to be correlated with disease severity. HAdV viremia may be useful tool to add further evidence of acute HAdV infection.

Disclosures

A. Leber, BioFIre Diagnostics: Research Contractor and Scientific Advisor, Research support, Speaker honorarium and Travel expenses
Feasibility and Validation of Viral Respiratory Disease Surveillance in a Combat Theater Using the Filmarray Respiratory Panel
Authors: Maves Ryan , Larson Derek , Dempsey Michael , Connors Benjamin , Baldwin James , Thomas Richard , Starr Clarise
Published: October 2017

Background

Viral respiratory infections are a significant threat to deployed military units. Pathogen-based surveillance may be hampered by limitations in trained personnel in theater, difficulty with specimen shipment, and technical issues with equipment maintenance. In this project, we evaluated the performance of the FilmArray respiratory panel at military clinics in Afghanistan and compare results to testing performed in the United States.

Methods

Participants were recruited after presenting at military clinics at Bagram Airfield (BAF), Afghanistan, in 2013–2014 with fever (≥38° C) and respiratory symptoms (cough, dyspnea, chest pain, and/or sore throat). General medical laboratory staff at BAF were trained to operate the FilmArray; nasopharyngeal swabs were obtained and tested in-theater using the FilmArray respiratory panel (Biofire Diagnostics, Salt Lake City, UT). Samples were then shipped to the USAFSAM Applied Technology Center in 50% RNALater (Qiagen, Valencia, CA) without dry ice and then retested using the same panel. Selected influenza isolates then underwent sequencing to evaluate for potential novel circulating strains.

Results

29 specimens underwent testing. A virus was identified on FilmArray in 22/29 specimens at BAF and 24/29 specimens at USAFSAM, of whom 17/29 had influenza A. Positive results between BAF and USAFSAM were concordant in all cases; 2 of the negative results at BAF were identified as having influenza A and rhinovirus, respectively. Among those with influenza A, all but one had undergone seasonal influenza vaccination. 5 influenza isolates then underwent sequencing; 2 were A(H1N1pdm09) consistent with the predominant 2012–2013 strain, while 3 were A(H3N2) viruses with HA mutations that differed from those in the 2013–2014 vaccine strain. No resistance-associated neuraminidase mutations were identified.

Conclusion

Surveillance using the FilmArray system is effective and feasible in theater by general laboratory staff. H1N1 and H3N2 influenza A viruses predominated in this sample of acute respiratory infections in a deployed military setting despite high vaccination rates. The use of the RNALater preservative is an effective method for specimen transport without requiring a cold chain and may facilitate biosurveillance in remote settings.

Disclosures

All authors: No reported disclosures.
Clinical Predictors of Shigella and Campylobacter Infection in Children in the United States
Authors: Smith Timothy , Ye Xiangyang , Stockmann Chris , Cohen Daniel , Leber Amy , Daly Judy , Jackson Jami , Selvarangan Rangaraj , Kanwar Neena , Bender Jeffery , Bard Jennifer Dien , Festekjian Ara , Duffy Susan , Larsen Chari , Baca Tanya , Holmberg Kristen , Bourzac Kevin , Chapin Kimberle C , Pavia Andrew , Leung Daniel
Published: October 2017

Background

Infectious gastroenteritis is a major cause of morbidity and mortality among children worldwide. While most episodes are self-limiting, for select pathogens such as Shigella and Campylobacter, etiological diagnosis may allow effective antimicrobial therapy and aid public health interventions. Unfortunately, clinical predictors of such pathogens are not well established and are based on small studies using bacterial culture for identification.

Methods

We used prospectively collected data from a multi-center study of pediatric gastroenteritis employing multi-pathogen molecular diagnostics to determine clinical predictors associated with 1) Shigella and 2) Shigella or Campylobacter infection. We used machine learning algorithms for clinical predictor identification, then performed logistic regression on features extracted plus pre-selected variables of interest.

Results

Of 993 children enrolled with acute diarrhea, we detected Shigella spp. in 56 (5.6%) and Campylobacter spp. in 24 (2.4%). Compared with children who had neither pathogen detected (of whom, >70% had ≥1 potential pathogen identified), bloody diarrhea (odds ratio 4.0), headache (OR 2.2), fever (OR 7.1), summer (OR 3.3), and sick contact with GI illness (OR 2.2), were positively associated with Shigella, and out-of-state travel (OR 0.3) and vomiting and/or nausea (OR 0.4) were negatively associated (Table). For Shigella or Campylobacter, predictors were similar but season was no longer significantly associated with infection.

Conclusion

These results can create prediction models and assist clinicians with identifying patients who would benefit from diagnostic testing and earlier antibiotic treatment. This may curtail unnecessary antibiotic use, and help to direct and target appropriate use of stool diagnostics.

Disclosures

A. Leber, BioFIre Diagnostics: Research Contractor and Scientific Advisor, Research support, Speaker honorarium and Travel expenses J. Daly, Biofire: Grant Investigator, Grant recipient R. Selvarangan, BioFire Diagnostics: Board Member and Investigator, Consulting fee and Research grant Luminex Diagnostics: Investigator, Research grant J. Dien Bard, BioFire: Consultant and Investigator, Research grant and Speaker honorarium K. Holmberg, BioFire Diagnostics: Employee, Salary K. Bourzac, BioFire Diagnostics: Employee, Salary K. C. Chapin, BioFire Diagnstics: Investigator, Research support A. Pavia, BioFire Diagnostics: Grant Investigator, Research grant
Gastroenteritis Severity: A Prospective Cohort Comparison of Children in Emergency Department and Home Settings
Authors: Vanderkooi Otto G , Xie Jianling , Lee Bonita , Ali Samina , Pang Xiao-Li , Chui Linda , Payne Daniel C , Tarr Phillip , Zhuo Ran , Parsons Brendon , Osterreicher Lara , Kim Kelly , Freedman Stephen
Published: October 2017

Background

While nearly 2 million children are brought to emergency department (ED) annually due to vomiting and/or diarrhea from acute gastroenteritis (AGE), it is estimated that 90% of AGE cases do not seek medical care. We sought to determine whether the disease severity and enteropathogen burden of disease of children with AGE brought for ED care is different from those cared for at home.

Methods

Subjects were prospectively recruited by the APPETITE team in pediatric EDs in 2 urban centers and via HealthLink, a province-wide nurse telephone advice line. Eligibility criteria included: < 18 years old, AGE defined by ≥ 3 episodes of vomiting or diarrhea in the preceding 24 hours, and < 7 days of symptoms. The primary outcome was index encounter disease severity quantified using the modified Vesikari Scale (MVS) score. To eliminate the impact of the index encounter on the score we excluded the index ED visit and intervention from all calculations. Secondary objectives included the enteropathogen burden of disease. Two rectal swabs and stool were collected and tested for enteropathogens by enteric bacterial culture, Luminex xTAG GPP, and a 5-virus in-house RT-qPCR panel.

Results

Between December 9, 2014 and December 31, 2016, 1,623 participants were enrolled with 81.5% from the EDs. Median age was 20.1 months. Children who went to ED were less likely to have a family physician (62 vs. 82%, P < 0.001), more likely to have clinical dehydration (Clinical Dehydration Scale score 3 vs 1, P < 0.001) and vomiting (91 vs. 85%, P = 0.004), previously received IV fluids (4.1 vs. 0.7%, P = 0.001) or been admitted (5.4 vs. 1.3%, P = 0.002). The MVS score was similar between groups when the contribution of the index visit to the score was excluded (8.1 vs. 7.8, P = 0.15). Participants recruited in the ED were not significantly more likely to have bacterial pathogens (8.0 vs. 3.7%, P = 0.09) but were less likely to have viral pathogens identified (64.1 vs. 80.7, P < 0.001).

Conclusion

Children presenting for ED care had disease severity scores that were similar to children managed at home when the contribution of the index ED visit was accounted for. Viral pathogens were more common in AGE receiving care at home while those presenting to the ED and potentially have a clinically greater likelihood of having a bacterial enteropathogen.

Disclosures

All authors: No reported disclosures.
Risk Factors for the Development of Bacteremia in Previously Healthy Children with Non-typhoidal Salmonella Gastroenteritis
Authors: Burdick Bethany , Dutta Ankhi , Hess Lauren , Minard Charles
Published: October 2017

Background

Non-typhoidal Salmonella (NTS) causes approximately 1.2 million illnesses per year in the United States. There are very few pediatric studies which has investigated the risk factors for NTS bacteremia in healthy children with NTS gastroenteritis (NTS-AGE).

Methods

This was a retrospective study of children admitted to Texas Children’s Hospital, Houston, TX, with NTS-AGE from 2007–2016. Exclusion criteria included: patients aged ≤3 m or > 18 years, immunodeficiencies, hemoglobinopathies, extraintestinal manifestations or those in whom blood cultures were not obtained. Demographics, clinical and laboratory data were collected from electronic medical records. Patients with NTS bacteremia (NTS-B) were compared with patients who were non-bacteremic (NTS-NB).

Results

Of 350 patients reviewed, 83 patients met inclusion criteria: 53 with NTS-B and 30 NTS-NB. The median age of diagnosis was 1.58 years (range 3.5 months-18 years). Thirty-nine patients (47.0%) were female and 44 (53.0%) were male. Majority of patients were non-Hispanic White (n = 70; 84.3%). The most common serotype was Salmonella Group C (n = 41(49.4%). There was no difference in risk factors between NTS-B vs. NTS-NB in terms of age, duration of diarrhea prior to admission, travel or pet exposure, prior antibiotic exposure or white blood cell count at presentation. Duration of fever prior to admission was statistically significant with median duration for NTS-B being 6.11 days compared with NTS-NB at 1.97 days (P =  0.0000006). There was an increased trend for bacteremia in males and Salmonella Group C bacteremia (P = 0.07 and P = 0.08 respectively).

Conclusion

To our knowledge this is first pediatric study in the United States to evaluate risk factors for NTS bacteremia in healthy children with NTS-AGE. Duration of fever prior to admission was associated with increased risk of NTS-B along with increased trend with males and infection with Group C Salmonella. These risk factors should prompt clinicians to monitor patients with NTS-AGE closely and help in deciding whether antimicrobials are warranted or not.

Disclosures

All authors: No reported disclosures.
Impact of Fecal Microbiota Transplantation on Digestive Tract Colonization due to Carbapenem-resistant Enterobacteriacae and Vancomycin-resistant Enterococci
Authors: Davido Benjamin , Batista Rui , Michelon Hugues , Escaut Lelia , Fessi Hafedh , Senard Olivia , Matt Morgan , Deconinck Laurene , De Truchis Pierre , Salomon Jérôme , Dinh Aurelien
Published: October 2017

Background

Fecal Microbiota Transplantation (FMT) has proved to be an efficient therapy for recurrent C. difficile infection. Its indication is currently discussed for the decolonization of Multidrug-resistant organisms (MDRO) on the basis of mice experiments. Two recent publications suggest that it could be an efficient strategy for patients colonized with digestive MDRO colonization but few data are available for Carbapenem-Resistant Enterobacteria (CRE) and Vancomycin-Resistant Enterococcus (VRE) colonization.

Methods

We performed a FMT among patients colonized by CRE or VRE documented by at least 3 nonconsecutive positive swabs (including one in the week prior to the FMT).

Procedure: 2 days prior to the FMT, patients received a proton pump inhibitor and a naso-duodenal tube was inserted to perform a bowel lavage with X-prep. FMT was performed with frozen feces from 4 donors previously screened for potential diseases using 5 syringes of 50 cc of feces diluted with saline. Patients were discharged after 24h and benefited of outpatient control swabs (PCR + culture) on day 7, 14, 21, 28 and each month during 3 months in order to assess the decolonization. The study is registered at ClinicalTrials.gov (NCT03029078).

Results

Seventeen individuals were included. Mean age was 69 ± 12.7 (SD) years.

Eight patients were positive for CRE (KPC, OXA48 or NDM-1) and 9 for VRE.

All suffered from severe underlying condition (hemodialysis, dementia, cirrhosis) or chronic wounds. Median functional autonomy scale was evaluated using the French Iso-Resources Groups (GIR)=4/6 IQR[3–6] supporting they were dependent persons.

At 1-month follow-up, 3/8 patients were free from CRE and 5/9 from VRE. At 3-month follow-up, 3/8 patients were still free from CRE whereas 7/8 were free from VRE, considering one death from cirrhosis.

Moreover, one of them received antibiotics during a week for a hospital-acquired infection a long time after FMT. No adverse events were reported.

Conclusion

FMT seems to be an attractive option to eradicate colonization of MDRO, especially for VRE. Limited data are available in the literature to determine response factors. Meanwhile its efficacy is moderate; it provides an alternative solution to quarantine for fragile and frequently hospitalized patients. More data and a controlled trial are required.

Disclosures

All authors: No reported disclosures.
The Global Burden of Shigella and Enterotoxigenic E. coli: Results from the Global Burden of Disease Study 2016
Authors: Khalil Ibrahim
Published: October 2017

Background

Diarrhea is the seventh leading cause of death globally, responsible for more than 1,600,000 deaths in 2016 and nearly 90% of these deaths occurred in sub-Saharan Africa and South Asia. The Global Burden of Disease Study (GBD) is an annual effort to produce and refine estimates of diarrheal disease burden attributable to Shigella spp., enterotoxigenic Escherichia coli (ETEC), and other enteric pathogens.

Methods

We used a counter-factual approach to estimate deaths, incidence, years of life lost (YLLs), years living with disability (YLDs), and total disability adjusted life years (DALYs) attributable to diarrhea and its etiologies, including Shigella and ETEC. To estimate the burden of diarrhea etiologies, we conducted a systematic review of the proportion of diarrheal cases positive for each pathogen and modeled these data using a Bayesian meta-regression tool called DisMod-MR. This tool generates estimates of the pathogen distribution for national and some subnational geographies, all age groups, and for both sexes from 1990 to 2016. We used these estimates, in conjunction with odds ratios for diarrhea given pathogen detection from the Global Enteric Multicenter Study, to calculate the population attributable fraction for each pathogen.

Results

In 2016, Shigella was responsible for 75,000 deaths among children under-5 and 270,000 deaths among all ages and ETEC was responsible for 22,000 deaths among children under-5 and 60,000 deaths among all ages. Shigella and ETEC ranked second and fourth with regard to pathogen contributions to global diarrheal deaths.

Conclusion

The global burden of disease attributable to Shigella and ETEC is substantial. GBD 2016 estimates on the age- and location-specific impact of Shigella and ETEC enable evidence-based decision making regarding interventions to reduce the burden of these pathogens. Our findings call for accelerated efforts for the development of vaccines against ETEC and Shigella.

Disclosures

All authors: No reported disclosures.
Frequency of Antimicrobial Resistance in Shiga Toxin-Producing Escherichia coli (STEC) and Non-Typhoidal Salmonella (NTS) Clinical Infections and Association with Epidemiological Factors
Authors: Mukherjee Sanjana , Mosci Rebekah , Anderson Chase , Snyder Brian , Collins James , Rudrik James , Manning Shannon D
Published: October 2017

Background

STEC and NTS are leading causes of foodborne infections in the US. Monitoring resistance in these pathogens is essential to understand the distribution of resistance profiles and because of the high likelihood of horizontal transfer of resistance genes to other pathogens. Data involving resistance in clinical STEC and NTS isolates from Michigan is lacking.

Methods

Clinical STEC (n = 353) and NTS (n = 148) isolates from the MDHHS (2010–2014) were examined for resistance using disk diffusion, E-test or broth microdilution. Case information and epidemiological data for STEC isolates was extracted and associations with resistant infections were determined using chi square tests in SAS 9.3 and EpiInfo™ 7.

Results

Overall, 31 (8.8%, n = 353) STEC isolates were resistant to at least one antibiotic; high frequencies of resistance were observed for ampicillin (7.4%) and trimethoprim-sulfamethoxazole (4.0%). Resistance to ciprofloxacin (0.28%) and all three drug classes (0.28%) was less common. Preliminary results indicate that O157 resistance to ampicillin (4.8%) and trimethoprim-sulfamethoxazole (3.4%) was higher in Michigan compared with national frequencies (ampicillin = 2.7%, trimethoprim-sulfamethoxazole= 1.5%). Higher resistance frequencies were also observed in counties with high (11.3%) vs. low (7.7%) antibiotic prescription rates. For NTS, 23 (15.5%) isolates were resistant to ≥1 antibiotic. Resistance varied by serotype with high frequencies in Typhimurium (20%, n = 20), Newport (17.6%, n = 17) and Enteritidis (4.8%, n = 42); 11 (7.4%) NTS isolates were resistant to ≥3 antimicrobial classes.

Conclusion

Continuous monitoring of resistance in clinical STEC and NTS is warranted due to their importance as food pathogens. The identification of risk factors for resistance is crucial to develop alternative prevention practices to reduce the health burden of resistant infections in Michigan, which is not part of the FoodNet surveillance network.

Disclosures

All authors: No reported disclosures.
Activity of Ceftolozane-Tazobactam and Comparators When Tested against Bacterial Surveillance Isolates Collected from Pediatric Patients in the US during 2012–2016 as Part of a Global Surveillance Program
Authors: Shortridge Dee , Duncan Leonard R , Pfaller Michael a , Flamm Robert K
Published: October 2017

Background

Ceftolozane-tazobactam (C-T) is an antibacterial combination of a novel antipseudomonal cephalosporin and a β-lactamase inhibitor. C-T was approved by the US Food and Drug Administration in 2014 and by the European Medicine Agency in 2015 to treat complicated urinary tract infections, acute pyelonephritis, and complicated intra-abdominal infections in adults. The Program to Assess Ceftolozane-Tazobactam Susceptibility (PACTS) monitors C-T resistance to gram-negative (GN) isolates worldwide.

Methods

A total of 4121 GN isolates were collected during 2012–2016 from pediatric patients (<18 years old) in 31 US hospitals and tested for C-T susceptibility (S) by CLSI broth microdilution method in a central monitoring laboratory (JMI Laboratories). Other antibiotics tested were amikacin (AMK), cefepime (FEP), ceftazidime (CAZ), colistin (COL), levofloxacin (LVX), meropenem (MER), and piperacillin-tazobactam (TZP). Antibiotic-resistant phenotypes identified using CLSI (2017) clinical breakpoints included: carbapenem-resistant Enterobacteriaceae (CRE), non-CRE extended-spectrum β-lactamase screen positive (ESBL, non-CRE), ceftazidime-nonsusceptible (CAZ-NS), and meropenem-NS (MER-NS). EUCAST (2017) COL clinical breakpoints were used for Enterobacteriaceae (ENT).

Results

The most common infection type in hospitalized pediatric patients was pneumonia (n = 1,488) followed by urinary tract infection (n = 1,143) and bloodstream infection (n = 767). A total of 2,969 ENT and 1,152 non-enterics were isolated. The 5 most common species were Escherichia coli (EC: 1,311), Pseudomonas aeruginosa (PSA: 821 isolates), Klebsiella pneumoniae (KPN: 429), Enterobacter cloacae complex (ECC: 360), and Serratia marcescens (SM: 264). Susceptibilities of C-T and comparators for the main species and resistant phenotypes are shown in the Table. Only 7 isolates were CRE in this study.

Conclusion

C-T demonstrated good activity against pediatric ENT isolates (96.1%S), EC (99.2%S), and KPN (97.9%S). For ENT, all agents but COL had >90% S. For PSA, C-T demonstrated potent activity (99.5%S) and was the most potent antibiotic tested with activity similar to COL.

Disclosures

D. Shortridge, Merck: Research Contractor, Research grant; L. R. Duncan, Merck: Research Contractor, Research grant; M. A. Pfaller, Merck: Research Contractor, Research grant; R. K. Flamm, Merck: Research Contractor, Research grant
Analysis of Oritavancin Activity against Gram-Positive Clinical Isolates Responsible for Bacterial Endocarditis in United States and European Hospitals (2008–2016)
Authors: Pfaller Michael A , Sader Helio S , Shortridge Dee , Flamm Robert K , Mendes Rodrigo E
Published: October 2017

Background

Oritavancin (ORI) has documented in vitro activity against gram-positive (GP) isolates. This study analyzed ORI tested against organisms causing endocarditis in United States (US) and European (EU) sites.

Methods

A total of 424 organisms recovered from patients with a diagnosis of bacterial endocarditis at US and EU sites during the SENTRY Antimicrobial Surveillance Program (2008–2016) were included (see Table). Isolates were identified by standard biochemical algorithms and MALDI-TOF. Susceptibility (S) testing was performed by CLSI methods, and MICs were interpreted per CLSI and/or EUCAST criteria.

Results

Among the 424 isolates, 212 (50.0%) were S. aureus (SA; 31.6% methicillin-resistant [MRSA]), 47 (11.1%) were coagulase-negative staphylococci (CoNS), 81 (19.1%) were E. faecalis (EFC), 21 (5.0%) were E. faecium (EFM), 24 (5.7%) were BHS, and 39 (9.2%) were viridans group streptococci (VGS). ORI had similar MIC90 values (0.06 µg/mL) against SA and CoNS, inhibiting 98.8% of these isolates at ≤0.12 µg/mL. ORI MIC50 values were 8- to 32-fold lower than those for vancomycin (VAN), daptomycin (DAP), and ceftaroline (CPT) against staphylococci. ORI showed MICs against EFM (MIC50/90, 0.008/0.03 µg/mL) that were 2-fold lower than against EFC (MIC50/90, 0.015/0.03 µg/mL; 97.5%S against all or 100%S against indicated VAN-S isolates). ORI inhibited 98.0% of all enterococci, including VAN-resistant isolates at ≤0.12 µg/mL. VAN, DAP, ampicillin (MIC50/90, ≤1/2 µg/mL), and linezolid (LZD) (MIC50/90, 1/2 µg/mL) were similarly active against EFC, while DAP and LZD had coverage (100.0%S) against EFM. Overall, BHS were highly S to all agents tested, except for erythromycin (70.8%S) and tetracycline (43.5%S). ORI was the most active agent (MIC90, 0.12 µg/mL) tested against VGS.

Conclusion

ORI showed potent in vitro activity against isolates recovered from patients with endocarditis in US and EU sites. The data presented here warrant further investigations to determine whether ORI has a role for treating endocarditis.

Disclosures

M. A. Pfaller, The Medicines Company: Research Contractor, Research grant; H. S. Sader, The Medicines Company: Research Contractor, Research grant; D. Shortridge, The Medicines Company: Research Contractor, Research grant; R. K. Flamm, The Medicines Company: Research Contractor, Research grant; R. E. Mendes, The Medicines Company: Research Contractor, Research grant
In Vitro Evaluation of Delafloxacin Activity when Tested Against Contemporary community-Acquired Bacterial Respiratory Tract Infection Isolates (2014–2016): Results from the Sentry Antimicrobial Surveillance Program
Authors: Shortridge Dee , Streit Jennifer M , Huband Michael D , Rhomberg Paul R , Flamm Robert K
Published: October 2017

Background

Delafloxacin (DLX) is a broad-spectrum fluoroquinolone (FQ) antibacterial that has completed clinical development (oral and intravenous formulations) with the new drug application currently under the Food and Drug Administration review for the treatment of acute bacterial skin and skin structure infections (ABSSSI). DLX is also in clinical trials for community-acquired bacterial pneumonia. In this study, in vitro susceptibility results for DLX and comparator agents were determined for clinical isolates from community-acquired respiratory tract infections (CA-RTI) collected in medical centers in the United States and Europe participating in the SENTRY surveillance program during 2014–2016.

Methods

A total of 3,093 isolates that included 1,673 Streptococcus pneumoniae (SPN), 805 Haemophilus influenzae (HI) and 555 Moraxella catarrhalis (MC) were collected during 2014–2016 and included only 1 isolate/patient/infection episode. Isolate identifications were confirmed at JMI Laboratories. Susceptibility testing was performed according to CLSI reference broth microdilution methodology, and results were interpreted per CLSI (2017) breakpoints. Other antibacterials tested included levofloxacin (LVX) and penicillin. Β-lactamase production for HI and MC was determined by the nitrocephin disk test.

Results

DLX demonstrated potent in vitro activity against SPN (MIC50/90 0.015/0.03 mg/L). Activity remained the same for penicillin-intermediate or -resistant isolates. For 23 LVX nonsusceptible SPN, the DLX MIC50/90 were 0.12/0.25 mg/L with all isolates having DLX MIC values ≤1 mg/L. For HI, the DLX MIC50/90 were ≤0.001/0.004 mg/L, and for MC the MIC50/90 were 0.008/0.008 mg/L. DLX activity was unaffected by the presence of β-lactamase for either HI or MC. Activity of DLX was similar for US and European isolates.

Conclusion

Delafloxacin demonstrated potent in vitro antibacterial activity against CA-RTI pathogens, including SPN, HI, and MC. These data support the continued study of DLX as a potential treatment for community-acquired pneumonia.

Disclosures

D. Shortridge, Melinta Therapeutics: Research Contractor, Research grant;

J. M. Streit, Melinta Therapeutics: Research Contractor, Research grant; M. D. Huband, Melinta Therapeutics: Research Contractor, Research grant; P. R. Rhomberg, Melinta Therapeutics: Research Contractor, Research grant; R. K. Flamm, Melinta Therapeutics: Research Contractor, Research grant
In vitro Susceptibility Testing of Essential Oils against Gram-positive and Gram-negative Clinical Isolates, including Carbapenem-resistant Enterobacteriaceae (CRE)
Authors: Patterson Jan E , McElmeel M.L , Wiederhold Nathan P
Published: October 2017

Background

In the era of antibiotic resistance, alternative anti-infectives must be explored. The National Action Plan for Combating Antibiotic-Resistant Bacteria calls for developing nontraditional therapeutics, including natural compounds such as essential oils (EOs) (Goal 4.4). A pilot study previously showed in vitro activity of EOs against CRE and warranted further study of their antibacterial activity. We studied cinnamon bark, clove, lavender, lemongrass, eucalyptus, oregano, rosemary, thyme, tea tree, manuka, and Thieves® blend (Young Living Essential Oils, Lehi UT) against an expanded panel of Gram-positive and Gram-negative isolates.

Methods

30 Gram-positive and 70 Gram-negative clinical isolates, including CRE, were tested using CLSI methods. Isolates were grown overnight on TSA; 0.5 McFarland suspensions in sterile water were swabbed over Mueller–Hinton agar using the Kirby–Bauer method. 20 μl of full-strength oils were pipetted onto blank paper disks in a sterile dish. Disks were placed aseptically onto the plates immediately after inoculating disks. Vancomycin was tested with Gram-positives and meropenem with Gram-negatives. Median zone diameters are shown.

Results

EOs oregano, thyme, cinnamon bark, and lemongrass had the largest zones of inhibition against Gram-positive organisms and were larger than those of vancomycin for MRSA/MSSA. Cinnamon bark had the largest zone of inhibition against P. aeruginosa and was larger than that of meropenem. Oregano, thyme, cinnamon bark had the largest zones of inhibition against Enterobacteriaceae and were larger than those of meropenem against K. pneumoniae and E. cloacae.

Conclusion

Essential oils showed significant in vitro activity against clinical isolates, including CRE. Further study of the clinical activity of essential oils is warranted.

Disclosures

J. E. Patterson, Young Living Essential Oils: Independent Contractor, Salary
In Vitro Activity of Lefamulin Against a Global Collection of Bacterial Pathogens Commonly Causing Community-Acquired Bacterial Pneumonia (CABP, SENTRY 2015)
Authors: Paukner Susanne , Sader Helio S , Streit Jennifer M , Flamm Robert K , Gelone Steven P
Published: October 2017

Background

CABP is the number one reason for death by infectious diseases worldwide and emerging resistance complicates its treatment. Lefamulin is the first semi-synthetic pleuromutilin antibiotic for IV and oral use in humans. It is currently in Phase 3 trials for the treatment of CABP in adults. Lefamulin effectively and selectively inhibits bacterial translation by binding to the peptidyl transferase center (PTC) via four H-bonds and other interactions at the A- and P-site resulting in an “induced fit.” This study investigated the activity of lefamulin and comparators against a contemporary set of bacterial pathogens associated with community-acquired respiratory infections collected worldwide.

Methods

Unique patients’ isolates (n = 2817) were collected globally in US (19.7%), Europe (36.9%), Latin America (5.7%) and Asia-Pacific region (37.6%) (30 countries, 116 sites) from adult and pediatric patients with respiratory tract infection (88.0%), bloodstream infections (5.5%) and other infections (2.4%). Lefamulin and comparators were tested by CLSI broth microdilution and susceptibility was determined using the CLSI (2017) breakpoints.

Results

LEF was the most potent compound tested, with 99.7% of all S. pneumoniae isolates being inhibited at a concentration of ≤0.25 mg/L (MIC50/90 values of 0.06/0.12 mg/L) and its activity was not affected by resistance to other antibiotic classes. S. pneumoniae isolates were largely susceptible to levofloxacin (99.1%) and ceftriaxone (96.5%), while 34.5%, 23.3% and 16.8% of isolates were resistant to macrolides, tetracycline and clindamycin, respectively. Lefamulin also showed potent activity against H. influenzae (MIC50/90 of 0.5/1 mg/L), including 22.0% of ß-lactamase producing strains, and M. catarrhalis (0.06/0.12 mg/L).

Conclusion

Lefamulin demonstrated potent in vitro activity against this global collection of contemporary respiratory pathogens and its activity was unchanged regardless of resistance phenotype to the other antibiotic classes including macrolides, ß-lactams, tetracyclines or fluoroquinolones. These data support the continued clinical development of lefamulin for the treatment of respiratory tract infections, including CABP.

Disclosures

S. Paukner, Nabriva Therapeutics: Employee and Shareholder, Salary; H. S. Sader, Nabriva Therapeutics: Research Contractor, Research grant; J. M. Streit, Nabriva Therapeutics: Research Contractor, Research grant; R. K. Flamm, Nabriva Therapeutics: Research Contractor, Research grant; S. P. Gelone, Nabriva Therapeutics: Employee and Shareholder, Salary
In Vitro Activity of Omadacycline and Comparator Compounds Against Gram-positive Isolates Collected in the USA During 2016 as Part of a Global Surveillance Program
Authors: Huband Michael D , Pfaller Michael a , Sader Helio S , Flamm Robert K
Published: October 2017

Background

Omadacycline (OMC) is a broad spectrum aminomethylcycline antibacterial in late stage clinical development (PO and IV formulations) for treatment of acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). OMC has potent in vitro activity against gram-positive (GP) pathogens expressing common resistance mechanisms to penicillins, tetracyclines, fluoroquinolones and macrolides.

Methods

A total of 4,122 GP isolates were collected in 2016 from 30 USA medical centers and included 2,366 staphylococci, 1,252 streptococci and 504 enterococci. A single isolate/patient/infection episode was included. Identifications were confirmed by matrix-assisted laser desorption/ionization mass spectrometry and susceptibility (S) testing was performed using reference broth microdilution methods.

Results

OMC was equally active against methicillin-susceptible (55.1% MSSA) and -resistant (44.9% MRSA) Staphylococcus aureus (SA; MIC50/90, 0.12/0.25 µg/mL). All SA were S to daptomycin (DAP), linezolid (LZD) and vancomycin (VAN). In MRSA, S was lower for levofloxacin (LEV; 28.2%), clindamycin (CLI; 69.9%), and erythromycin (ERY; 10.9%). OMC (MIC50/90, 0.12/0.5 µg/mL) and tigecycline (TGC; MIC50/90, 0.06/12 µg/mL) were the most active agents against coagulase-negative staphylococci (CoNS) and methicillin-R CoNS. S. pneumoniae (including penicillin- [12.8% resistant], ceftriaxone- and ERY-resistant strains), viridans group streptococci (VGS) and β-hemolytic streptococci (including ERY and tetracycline resistant strains) were inhibited by low levels of OMC (MIC50/90 0.06/0.06–0.12 µg/mL) and TGC (MIC50/90 0.03–0.06/0.06–0.12 µg/mL). OMC was highly potent against enterococci (MIC50/90 0.12/0.25 µg/mL) including vancomycin-R isolates. Vancomycin resistance rates were 4.3% and 66.5% in E. faecalis and E. faecium, respectively.

Conclusion

OMC demonstrated potent activity against susceptible and resistant GP pathogens often associated with ABSSSI and CABP including staphylococci, S. pneumoniae, β-hemolytic streptococci, VGS and enterococci. These data support further omadacycline clinical studies, especially in infections where resistant GP isolates occur.

Disclosures

M. D. Huband, Paratek Pharma, LLC: Research Contractor, Research grant; M. A. Pfaller, Paratek Pharma, LLC: Research Contractor, Research grant; H. S. Sader, Paratek Pharma, LLC: Research Contractor, Research grant R. K. Flamm, Paratek Pharma, LLC: Research Contractor, Research grant
Ceftazidime-avibactam and Meropenem Double Disk Diffusion Test for Identifying Carbapanem-Resistant Enterobacteriaceae and Distinguishing Between Serine and Metallo-β-Lactamase Producing Organisms
Authors: Lin Lynn-Yao , Critchley Ian , Melnick David
Published: October 2017

Background

Early detection of carbapenem-resistant Enterobacteriaceae(CRE) is crucial for selection of effective treatment. While KPC is the most prevalent carbapenemase in the US, phenotypic screening methods, such as the carbapenemase inactivation method (CIM) and CarbaNP, cannot easily distinguish between serine and metallo-β-lactamases (MBL). The aim of this study was to evaluate a simple double disk diffusion (DD) test to confirm carbapenem (meropenem) resistance (MER disk) and that resistance was due to a serine carbapenemase as indicated by susceptibility to ceftazidime-avibactam (CAZ-AVI disk). MBL-producing organisms are likely to be resistant to both MER and CAZ-AVI.

Methods

In total, 83 clinical isolates of Enterobacteriaceae were selected for the validation: 54 Klebsiella pneumoniae (KP), 16 Enterobacter cloacae (ECL) and 13 Escherichia coli (EC). All isolates were screened for specific β-lactamase genes (Checkpoints, Wageningen, Netherlands) and included KPC, OXA, IMP, VIM, NDM as well as strains with KPC and alterations on OmpK35 and OmpK36. Isolates were tested for susceptibility to MER and CAZ-AVI by disk diffusion and broth microdilution (BMD) per CLSI guidelines. Results were analyzed to evaluate suitability of the DD test to distinguish between serine and MBL-producing organisms.

Results

Overall correlation between disk and BMD was 97–100% for CAZ-AVI and 94–100% for MER. Among the 50 CRE that were susceptible to CAZ-AVI were strains positive for KPC, or OXA, or in combination with ESBLs. Among the 16 isolates that were resistant to both CAZ-AVI and MER were strains that produced MBLs such as IMP, VIM and NDM and included strains with alteration in OmpK35 and OmpK36. Among the 17 carbapenem-susceptible control strains all were susceptible to both agents and were positive for AmpC or ESBLs.

Conclusion

The CAZ-AVI and MER DD test was successful in confirming CRE phenotype and in distinguishing between serine carbapenemase-producing and MBL-producing organisms. The test will be useful in screening patients in future trials to evaluate the efficacy of CAZ-AVI in global CRE studies where MBL’s are more prevalent in other geographic regions. Both disks are commercially available and can be performed in most clinical laboratories.

Disclosures

L. Y. Lin, Allergan plc: Employee, Salary; I. Critchley, Allergan plc: Employee, Salary; D. Melnick, Allergan plc: Employee, Salary
Antimicrobial Activity of Dalbavancin Tested against Staphylococcus aureus with Decreased Susceptibility to Glycopeptides, Daptomycin, and/or Linezolid from United States (US) Medical Centers
Authors: Sader Helio S , Mendes Rodrigo E , Duncan Leonard R , Pfaller Michael A , Flamm Robert K
Published: October 2017

Background

Dalbavancin (DALBA) was approved by the US Food and Drug Administration (2014) and European Medicines Agency (2015) for treating acute bacterial skin and skin structure infections. Dalbavancin activity was assessed against a large collection of S. aureus clinical isolates with decreased susceptibility (S) to key antimicrobial agents used to treat severe S. aureus infections.

Methods

The organism collection included isolates with decreased S to vancomycin (VAN; MIC ≥2 μg/mL; n = 1,141), daptomycin (DAPTO; MIC ≥2 μg/mL [resistant (R) per CLSI and EUCAST]; n = 48), telavancin (TLV; MIC ≥0.12 μg/mL; n = 73), teicoplanin (TEICO; MIC ≥4 μg/mL [non-S (NS) per EUCAST]; n = 143), and/or linezolid (LNZ; MIC ≥8 μg/mL [R per CLSI and EUCAST]; n = 25). Isolates were selected among 59,903 US isolates tested in 2002–2016. S testing was performed by CLSI methods and MIC results were interpreted per CLSI and EUCAST criteria.

Results

Only 8 of 59,903 (0.01%) S. aureus isolates tested were categorized as DALBA-NS (MIC, >0.25 μg/mL). DALBA retained activity against 99.3% of isolates with VAN MICs of ≥2 μg/mL (Table), whereas DAPTO (MIC50/90, 0.5/1 μg/mL) and LNZ (MIC50/90, 1/2 μg/mL) were active against 96.8% and 99.6% of isolates, respectively. DALBA (Table) and VAN (MIC50/90, 2/2 μg/mL) retained activity against 95.8% of DAPTO-NS S. aureus. When tested against TEICO-NS (EUCAST) isolates, S rates for DALBA, DAPTO, VAN, and LNZ were 95.1%, 95.8%, 97.9%, and 100.0%, respectively; and DALBA was 4- to 32-fold more potent than these comparator agents. All LNZ-R isolates (100.0%) were S to DALBA (MIC50/90, 0.06/0.06 μg/mL), DAPTO (MIC50/90, 0.5/0.5 μg/mL), and VAN (MIC50/90, 1/2 μg/mL), but DALBA was 8- and 16- to 32-fold more potent than DAPTO and VAN, respectively. MRSA rates ranged from 71.2–96.0% among these R subsets.

Conclusion

DALBA retained potent in vitro activity against S. aureus isolates, displaying decreased susceptibility to agents commonly used to treat serious infections and was consistently more potent than comparator agents.

Disclosures

H. S. Sader, Allergan: Research Contractor, Research grant; R. E. Mendes, Allergan: Research Contractor, Research grant; L. R. Duncan, Allergan: Research Contractor, Research grant; M. A. Pfaller, Allergan: Research Contractor, Research grant; R. K. Flamm, Allergan: Research Contractor, Research grant
In vitro Activity of Ceftaroline Against Pathogens Collected Globally from the AWARE Surveillance Program, 2016
Authors: Hackel Meredith , Iaconis Joseph , Sahm Dan
Published: October 2017

Background

Ceftaroline, the active metabolite of ceftaroline fosamil, is a cephalosporin developed for treating infections caused by Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), Streptococcus pneumoniae, β-hemolytic streptococci, and some Gram-negative pathogens. This study reports the in vitro activity of ceftaroline against clinically relevant isolates collected in 2016 from the AWARE Surveillance Program.

Methods

22,752 non-duplicate methicillin-sensitive S. aureus (MSSA), MRSA, S. pneumoniae, β-hemolytic streptococci (S. pyogenes, S. agalactiae, S. dysgalactiae) Haemophilus influenzae, and extended spectrum β-lactamase (ESBL)-negative Enterobacteriaceae were collected from (n/%) Asia/South Pacific (4,215/18.5%), Europe (12,962/57.0%), Latin America (3,384/14.9%), and Middle East/Africa (2,191/9.6%) during 2016. Isolates were from (n/%) complicated intraabdominal (2,149/9.5%), complicated urinary tract (3,029/13.3%), complicated skin and skin structure (8,271/36.4%), blood stream (2,422/10.6%) and lower respiratory tract infections (6,881/30.2%). MIC values were determined by broth microdilution and interpreted using CLSI breakpoints.

Results

Ceftaroline activity, based on % susceptibility (%S) and MIC90, is shown in the table. Ceftaroline was active in vitro against both Gram-positive (100% of MSSA, 93.6% of MRSA and 99.7% of S. pneumoniae) and Gram-negative (99.7% of H. influenzae and 91.7% of ESBL-negative Enterobacteriaceae) isolates.

Conclusion

Based on these data generated with isolates collected in 2016, ceftaroline exhibited potent in vitro activity against clinically relevant isolates, with >91% of all isolates susceptible at their CLSI breakpoints.

Funding: This study was sponsored by AstraZeneca. The AstraZeneca product ceftaroline fosamil was acquired by Pfizer in December 2016.

Disclosures

J. Iaconis, AstraZeneca: Employee and Shareholder, Salary and Shareholder in AstraZeneca