The Engineered Lysin, CF-370, is Active Against Antibiotic-Resistant Gram-Negative Pathogens In vitro and Synergizes with Meropenem in Experimental Pseudomonas aeruginosa Pneumonia.

BACKGROUND: Lysins (cell wall hydrolases) targeting Gram-negative organisms require engineering to permeabilize the outer membrane and access subjacent peptidoglycan to facilitate killing. In the current study, the potential clinical utility for engineered lysin, CF-370, was examined in vitro and in vivo against Gram-negative pathogens important in human infections. METHODS: MICs and bactericidal activity were determined using standard methods. An in vivo proof-of-concept efficacy study was conducted using a rabbit acute pneumonia model caused by Pseudomonas aeruginosa. RESULTS: CF-370 exhibited potent antimicrobial activity, with MIC50/90 values (in µg/mL) for: P. aeruginosa, 1/2; Acinetobacter baumannii, 1/1; Escherichia coli, 0.25/1; Klebsiella pneumoniae, 2/4; Enterobacter cloacae 1/4; and Stenotrophomonas maltophilia 2/8. CF-370 furthermore demonstrated: i) bactericidal activity; (ii) activity in serum; iii) a low propensity for resistance; iv) anti-biofilm activity; and v) synergy with antibiotics. In the pneumonia model, CF-370 alone decreased bacterial densities in lungs, kidneys and spleen vs. vehicle control, and demonstrated significantly increased efficacy when combined with meropenem (vs either agent alone). CONCLUSIONS: CF-370 is the first engineered lysin described with potent broad spectrum in vitro activity against multiple clinically-relevant Gram-negative pathogens, as well as potent in vivo efficacy in an animal model of severe invasive multi-system infection.

Exebacase Is Active In Vitro in Pulmonary Surfactant and Is Efficacious Alone and Synergistic with Daptomycin in a Mouse Model of Lethal Staphylococcus aureus Lung Infection.

Exebacase (CF-301) is a novel antistaphylococcal lysin (cell wall hydrolase) in phase 3 of clinical development for the treatment of Staphylococcus aureus bacteremia, including right-sided endocarditis, used in addition to standard-of-care antibiotics. In the current study, the potential for exebacase to treat S. aureus pneumonia was explored in vitro using bovine pulmonary surfactant (Survanta) and in vivo using a lethal murine pneumonia model. Exebacase was active against a set of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains, with an MIC90 of 2 µg/ml (n = 18 strains), in the presence of a surfactant concentration (7.5%) inhibitory to the antistaphylococcal antibiotic daptomycin, which is inactive in pulmonary environments due to specific inhibition by surfactant. In a rigorous test of the ability of exebacase to synergize with antistaphylococcal antibiotics, exebacase synergized with daptomycin in the presence of surfactant in vitro, resulting in daptomycin MIC reductions of up to 64-fold against 9 MRSA and 9 MSSA strains. Exebacase was also observed to facilitate the binding of daptomycin to S. aureus and the elimination of biofilm-like structures formed in the presence of surfactant. Exebacase (5 mg/kg of body weight 1 time every 24 h [q24h], administered intravenously for 3 days) was efficacious in a murine model of staphylococcal pneumonia, resulting in 50% survival, compared to 0% survival with the vehicle control; exebacase in addition to daptomycin (50 mg/kg q24h for 3 days) resulted in 70% survival, compared to 0% survival in the daptomycin-alone control group. Overall, exebacase is active in pulmonary environments and may be appropriate for development as a treatment for staphylococcal pneumonia.

Exebacase Demonstrates In Vitro Synergy with a Broad Range of Antibiotics against both Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus.

In vitro synergy between an antimicrobial protein lysin (cell wall hydrolase) called exebacase and each of 12 different antibiotics was examined against Staphylococcus aureus isolates using a nonstandard medium approved for exebacase susceptibility testing by the Clinical and Laboratory Standards Institute. In the checkerboard assay format, fractional inhibitory concentration index values of ≤0.5, consistent with synergy, were observed for the majority of interactions tested. Synergy was further confirmed in time-kill assays.

Antimicrobial Activity of Exebacase (Lysin CF-301) against the Most Common Causes of Infective Endocarditis.

Exebacase, a recombinantly produced lysin (cell wall hydrolase), and comparator antibiotics were tested by the broth microdilution method against strain sets of Staphylococcus and Streptococcus spp., which are the most common causes of infective endocarditis in humans. Exebacase was active against all Staphylococcus spp. tested, including S. aureus and coagulase-negative staphylococci (MIC50/90, 0.5/1 µg/ml). Activity against Streptococcus spp. was variable, with S. pyogenes, S. agalactiae, and S. dysgalactiae (MIC50/90, 1/2 µg/ml) among the most susceptible.

The Antistaphylococcal Lysin, CF-301, Activates Key Host Factors in Human Blood To Potentiate Methicillin-Resistant Staphylococcus aureus Bacteriolysis.

Bacteriophage-derived lysins are cell-wall-hydrolytic enzymes that represent a potential new class of antibacterial therapeutics in development to address burgeoning antimicrobial resistance. CF-301, the lead compound in this class, is in clinical development as an adjunctive treatment to potentially improve clinical cure rates of Staphylococcus aureus bacteremia and infective endocarditis (IE) when used in addition to antibiotics. In order to profile the activity of CF-301 in a clinically relevant milieu, we assessed its in vitro activity in human blood versus in a conventional testing medium (cation-adjusted Mueller-Hinton broth [caMHB]). CF-301 exhibited substantially greater potency (32 to ≥100-fold) in human blood versus caMHB in three standard microbiologic testing formats (e.g., broth dilution MICs, checkerboard synergy, and time-kill assays). We demonstrated that CF-301 acted synergistically with two key human blood factors, human serum lysozyme (HuLYZ) and human serum albumin (HSA), which normally have no nascent antistaphylococcal activity, against a prototypic methicillin-resistant S. aureus (MRSA) strain (MW2). Similar in vitro enhancement of CF-301 activity was also observed in rabbit, horse, and dog (but not rat or mouse) blood. Two well-established MRSA IE models in rabbit and rat were used to validate these findings in vivo by demonstrating comparable synergistic efficacy with standard-of-care anti-MRSA antibiotics at >100-fold lower lysin doses in the rabbit than in the rat model. The unique properties of CF-301 that enable bactericidal potentiation of antimicrobial activity via activation of "latent" host factors in human blood may have important therapeutic implications for durable improvements in clinical outcomes of serious antibiotic-resistant staphylococcal infections.

Combination therapy with lysin CF-301 and antibiotic is superior to antibiotic alone for treating methicillin-resistant Staphylococcus aureus-induced murine bacteremia.

Lysins are bacteriophage-derived enzymes that degrade bacterial peptidoglycans. Lysin CF-301 is being developed to treat Staphylococcus aureus because of its potent, specific, and rapid bacteriolytic effects. It also demonstrates activity on drug-resistant strains, has a low resistance profile, eradicates biofilms, and acts synergistically with antibiotics. CF-301 was bacteriolytic against 250 S. aureus strains tested including 120 methicillin-resistant S. aureus (MRSA) isolates. In time-kill studies with 62 strains, CF-301 reduced S. aureus by 3-log10 within 30 minutes compared to 6-12 hours required by antibiotics. In bacteremia, CF-301 increased survival by reducing blood MRSA 100-fold within 1 hour. Combinations of CF-301 with vancomycin or daptomycin synergized in vitro and increased survival significantly in staphylococcal-induced bacteremia compared to treatment with antibiotics alone (P < .0001). Superiority of CF-301 combinations with antibiotics was confirmed in 26 independent bacteremia studies. Combinations including CF-301 and antibiotics represent an attractive alternative to antibiotic monotherapies currently used to treat S. aureus bacteremia.

'He does not see himself as being different': the perspectives of children and caregivers on relevant areas of functioning in cerebral palsy.

AIMS: In the context of the development of the International Classification of Functioning, Disability and Health (ICF) Core Sets for children and adolescents with cerebral palsy (CP), we investigated the strengths and limitations in functioning important to children with CP, through either child self-reports or caregiver proxy reports, using components of the International Classification of Functioning, Disability and Health for Children and Youth (ICF-CY). METHOD: We conducted semi-structured interviews with 10 children with CP (children self-reporting), 10 caregivers of children self-reporting (10 child-caregiver dyads), and 12 caregivers of children not self-reporting. Mean age 10 y 6 mo, range 4-16 y. A convenience sample was recruited representing Gross Motor Function Classification System (GMFCS) levels I to V. Interviews were audio-taped and the content covered all of the relevant ICF-CY components. The interviews were then transcribed verbatim and coded in N-Vivo 10 using the ICF-CY coding system. RESULTS: We identified 1956 themes that linked to 175 ICF-CY categories. Most of the themes were represented by the ICF-CY components activities and participation and environmental factors. The children interviewed discussed issues related to mobility, self-care, and recreation and leisure, whereas the caregivers focused more on physical limitations and on the environmental factors associated with everyday activities. INTERPRETATION: The children and their caregivers described many of the same areas of functioning but provided unique perspectives. Children talked more frequently about their abilities with CP, whereas the caregivers interviewed talked more about their concern over the limitations and broader issues facing their child. The findings highlight the need to explore the perspectives of both the child and the caregiver when characterizing the functional profile of children with CP.

The effects of motivating interventions on rehabilitation outcomes in children and youth with acquired brain injuries: a systematic review.

PRIMARY OBJECTIVE: To systematically review the evidence of the effects of motivating rehabilitation interventions on outcomes in children with acquired brain injury (ABI). METHODS: A literature search of six databases was conducted to identify intervention studies published until July 2013. The American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) systematic review methodology was used as a framework. Two reviewers independently extracted data and assessed level of evidence and quality of studies. RESULTS: Of 891 records initially retrieved, 166 were screened by abstract and 31 by full text; 10 studies comprised of five randomized controlled trials, two case series and three single subject research design studies met the inclusion criteria. Studies fell into three intervention categories: (1) token economy based interventions; (2) virtual reality (VR); and (3) memory and attention interventions. CONCLUSIONS: A paucity of evidence has examined the effects of rehabilitation interventions with a motivational component. Token economies can significantly enhance memory and response inhibition performance in children with ABI. VR systems are motivating, yet findings are limited by the lack of use and availability of psychometrically evaluated measures of motivation. Findings point to the need for further research to evaluate the effects of motivation-based interventions.

Evidence for outcomes of motivational rehabilitation interventions for children and adolescents with cerebral palsy: an American Academy for Cerebral Palsy and Developmental Medicine systematic review.

This study reviewed evidence regarding the effect of motivational rehabilitation interventions on outcomes in children with cerebral palsy. Six databases were searched for literature published up to May 2012. Included studies measured the purported motivating effects of motor-based rehabilitation interventions and the measured impact on outcomes. The American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) systematic review methodology was used as a framework. Eight studies evaluated outcomes of studies using virtual reality interventions and one in a functional therapy context. Conflicting evidence from three (level II and level III) studies exists about the impact of these motivating interventions on motor outcomes measured in body functions. No statistical evidence regarding activity and participation outcomes exists. A single level II study found no significant difference in participants' motivation between motivational and conventional interventions. This review revealed a paucity of research on the effects of motivational interventions. Weaknesses include a lack of consistency in the examination of motivational interventions, limited use of definitions or theories to ground the concept of motivation, and reliance on non-validated methodological tools. This body of evidence would be strengthened by the use and development of robust outcome measures of motivation.

Rapid bacteriolysis of Staphylococcus aureus by lysin exebacase.

Lysins (peptidoglycan hydrolases) are promising new protein-based antimicrobial candidates under development to address rising antibiotic resistance encountered among pathogenic bacteria. Exebacase is an antistaphylococcal lysin and the first member of the lysin class to have entered clinical trials in the United States. In this study, the bacteriolytic activity of exebacase was characterized with time-kill assays, turbidity reduction assays, and microscopy. Three methicillin-susceptible Staphylococcus aureus and three methicillin-resistant S. aureus isolates were tested in time-kill assays over a range of concentrations from 0.25 to 8 × MIC. Exebacase demonstrated a concentration-dependent killing and showed bactericidal activity (≥3 log10 kill achieved relative to the starting inoculum) within 3 h at 1 × MIC against all strains tested. Dose-dependent lysis by exebacase was, furthermore, observed in the turbidity reduction assay, wherein decreases in initial OD600 of 50% were observed within ~15 min at concentrations as low as 4 µg/mL. Membrane dissolution, loss of cytoplasmic material, and lysis were confirmed by video and electron microscopy. The demonstrated rapid bacteriolytic effect of exebacase is an important distinguishing feature of this novel modality. IMPORTANCE To guide the development of an investigational new antibacterial entity, microbiological data are required to evaluate the killing kinetics against target organism(s). Exebacase is a lysin (peptidoglycan hydrolase) that represents a novel antimicrobial modality based on degradation of the cell wall of Staphylococcus aureus. Killing by exebacase was determined in multiple assay formats including time-kill assays, wherein reductions of viability of ≥3 log10 colony-forming units/mL were observed within 3 h for multiple different isolates tested, consistent with very rapid bactericidal activity. Rapid reductions in optical density were likewise observed in exebacase-treated cultures, which were visually consistent with microscopic observations of rapid lysis. Overall, exebacase provides a novel antimicrobial modality against S. aureus, characterized by a rapid cidal and lytic activity.

Toolbox of multiple-item measures aligning with the ICF Core Sets for children and youth with cerebral palsy.

Selecting appropriate measure(s) for clinical and/or research applications for children and youth with Cerebral Palsy (CP) poses many challenges. The newly developed International Classification of Functioning, Disability and Health (ICF) Core Sets for children and youth with CP serve as universal guidelines for assessment, intervention and follow-up. The aims of this study were: 1) to identify valid and reliable measures used in studies with children and youth with CP, 2) to characterize the content of each measure using the ICF Core Sets for children and youth with CP as a framework, and finally 3) to create a toolbox of psychometrically sound measures covering the content of each ICF Core Set for children and youth with CP. All clearly defined multiple-item measures used in studies with CP between 1998 and 2015 were identified. Psychometric properties were extracted when available. Construct of the measures were linked to the ICF Core Sets. Overall, 83 multiple-item measures were identified. Of these, 68 measures (80%) included reliability and validity testing. The majority of the measures were discriminative, generic and designed for school-aged children. The degree to which measures with proven psychometric properties represented the ICF Core Sets for children and youth with CP varied considerably. Finally, 25 valid and reliable measures aligned highly with the content of the ICF Core Sets, and as such, these measures are proposed as a novel ICF Core Sets-based toolbox of measures for CP. Our results will guide professionals seeking appropriate measures to meet their research and clinical needs worldwide.

Comparing contents of outcome measures in cerebral palsy using the International Classification of Functioning (ICF-CY): a systematic review.

The International Classification of Functioning children and youth version (ICF-CY) provides a universal framework for defining and classifying functioning and disability in children worldwide. To facilitate the application of the ICF in practice, ICF based-tools like the "ICF Core Sets" are being developed. In the context of the development of the ICF-CY Core Sets for children with Cerebral Palsy (CP), the aims of this study were as follows: to identify and compare the content of outcome measures used in studies of children with CP using the ICF-CY coding system; and to describe the most frequently addressed areas of functioning in those studies. We searched multiple databases likely to capture studies involving children with CP from January 1998 to March 2012. We included all English language articles that studied children aged 2-18 years and described an interventional or observational study. Constructs of the outcome measures identified in studies were linked to the ICF-CY by two trained professionals. We found 231 articles that described 238 outcome measures. The outcome measures contained 2193 concepts that were linked to the ICF-CY and covered 161 independent ICF-CY categories. Out of the 161 categories, 53 (33.5%) were related to body functions, 75 (46%) were related to activities/participation, 26 (16.1%) were related to environmental factors, and 7 (4.3%) were related to body structures. This systematic review provides information about content of measures that may guide researchers and clinicians in their selection of an outcome measure for use in a study and/or clinical practice with children with CP.

Toward the development of the International Classification of Functioning Core Sets for children with cerebral palsy: a global expert survey.

The goal of the International Classification of Functioning is to standardize the classification of health and function of children around the world. To facilitate the application of this classification, International Classification of Functioning-based tools like the "Core Sets" are being developed. We conducted an international survey of professional experts to identify the most relevant areas of functioning in children with cerebral palsy. The questionnaire covered each component of the classification. In total, 193 professionals completed the survey (response rate 78%). Overall, 9706 answers were linked to the classification (pediatric version) by 2 professionals. From the experts' perspective, movement-related areas and social participation are the most relevant areas of functioning. Experts suggest a more comprehensive profile of functioning in particular in areas of personal capacity and social participation. The results of this survey will inform the development of the International Classification of Functioning Core Sets for children with cerebral palsy.