Considerations for the Use of Phage Therapy in Clinical Practice.

Increasing antimicrobial resistance and medical device-related infections have led to a renewed interest in phage therapy as an alternative or adjunct to conventional antimicrobials. Expanded access and compassionate use cases have risen exponentially but have varied widely in approach, methodology, and clinical situations in which phage therapy might be considered. Large gaps in knowledge contribute to heterogeneity in approach and lack of consensus in many important clinical areas. The Antibacterial Resistance Leadership Group (ARLG) has convened a panel of experts in phage therapy, clinical microbiology, infectious diseases, and pharmacology, who worked with regulatory experts and a funding agency to identify questions based on a clinical framework and divided them into three themes: potential clinical situations in which phage therapy might be considered, laboratory testing, and pharmacokinetic considerations. Suggestions are provided as answers to a series of questions intended to inform clinicians considering experimental phage therapy for patients in their clinical practices.

Patients' Experiences With Staphylococcus aureus and Gram-negative Bacterial Bloodstream Infections: A Qualitative Descriptive Study and Concept Elicitation Phase To Inform Measurement of Patient-reported Quality of Life.

BACKGROUND: Although Staphylococcus aureus and gram-negative bacterial bloodstream infections (SAB/GNB) cause substantial morbidity, little is known regarding patient perceptions' of their impact on quality of life (QOL). Guidance for assessing QOL and disease-specific measures are lacking. We conducted a descriptive qualitative study to gain an in-depth understanding of patients' experiences with SAB/GNB and concept elicitation phase to inform a patient-reported QOL outcome measure. METHODS: We conducted prospective one-time, in-depth, semi-structured, individual, qualitative telephone interviews 6- 8 weeks following bloodstream infection with either SAB or GNB. Patients were enrolled in an institutional registry (tertiary academic medical center) for SAB or GNB. Interviews were audio-recorded, transcribed, and coded. Directed content analysis identified a priori and emergent themes. Theme matrix techniques were used to facilitate analysis and presentation. RESULTS: Interviews were completed with 30 patients with SAB and 31 patients with GNB. Most patients were at or near the end of intravenous antibiotic treatment when interviewed. We identified 3 primary high-level concepts: impact on QOL domains, time as a critical index, and sources of variability across patients. Across both types of bloodstream infection, the QOL domains most impacted were physical and functional, which was particularly evident among patients with SAB. CONCLUSIONS: SAB/GNB impact QOL among survivors. In particular, SAB had major impacts on multiple QOL domains. A combination of existing, generic measures that are purposefully selected and disease-specific items, if necessary, could best capture these impacts. Engaging patients as stakeholders and obtaining their feedback is crucial to conducting patient-centered clinical trials and providing patient-centered care.

Pharmacokinetic and Pharmacodynamic Profiling of Minocycline for Injection following a Single Infusion in Critically Ill Adults in a Phase IV Open-Label Multicenter Study (ACUMIN).

Intravenous (i.v.) minocycline is increasingly used to treat infections caused by multidrug-resistant (MDR) Acinetobacter baumannii Despite its being approved nearly 50 years ago, published information on its pharmacokinetic (PK) profile is limited. This multicenter study examined the PK and probability of pharmacokinetic-pharmacodynamic (PK-PD) target attainment profile of i.v. minocycline in critically ill patients, with suspected or documented infection with Gram-negative bacteria. The PK study population included 55 patients who received a single 200-mg i.v. dose of minocycline. Plasma PK samples were collected predose and 1, 4, 12, 24, 36, and 48 h after initiation of minocycline. Total and unbound minocycline concentrations were determined at each time point. Probabilities of achieving the PK-PD targets associated with stasis and 1-log killing (free area under the curve above the MIC [fAUC:MIC] of 12 and 18, respectively) in an immunocompetent animal pneumonia infection model of A. baumannii were evaluated. A two-compartment population PK model with zero-order i.v. input and first-order elimination, which estimated a constant fraction unbound (fub) for minocycline, best characterized the total and unbound plasma minocycline concentration-time data. The only two covariates retained in the final PK model were body surface area (associated with central volume of distribution) and albumin (associated with fub). In the PK-PD probability of target attainment analyses, minocycline 200 mg i.v. every 12 h (Q12H) was predicted to result in a suboptimal PK-PD profile for patients with A. baumannii infections with MIC values of >1 mg/liter. Like all PK-PD profiling studies of this nature, these findings need clinical confirmation.

Simultaneous Evaluation of Diagnostic Assays for Pharyngeal and Rectal Neisseria gonorrhoeae and Chlamydia trachomatis Using a Master Protocol.

BACKGROUND: Pharyngeal and rectal Neisseria gonorrhoeae and Chlamydia trachomatis play important roles in infection and antibacterial resistance transmission, but no US Food and Drug Administration (FDA)-cleared assays for detection at these sites existed prior to this study. The objective was to estimate performance of assays to detect those infections in pharyngeal and rectal specimens to support regulatory submission. METHODS: We performed a cross-sectional, single-visit study of adults seeking sexually transmitted infection testing at 9 clinics in 7 states. We collected pharyngeal and rectal swabs from participants. The primary outcome was positive and negative percent agreement for detection of N. gonorrhoeae and C. trachomatis for 3 investigational assays compared to a composite reference. Secondary outcomes included positivity as well as positive and negative predictive values and likelihood ratios. Subgroup analyses included outcomes by symptom status and sex. RESULTS: A total of 2598 participants (79% male) underwent testing. We observed N. gonorrhoeae positivity of 8.1% in the pharynx and 7.9% in the rectum and C. trachomatis positivity of 2.0% in the pharynx and 8.7% in the rectum. Positive percent agreement ranged from 84.8% to 96.5% for different anatomic site infection combinations, whereas negative percent agreement was 98.8% to 99.6%. CONCLUSIONS: This study utilized a Master Protocol to generate diagnostic performance data for multiple assays from different manufacturers in a single study population, which ultimately supported first-in-class FDA clearance for extragenital assays. We observed very good positive percent agreement when compared to a composite reference method for the detection of both pharyngeal and rectal N. gonorrhoeae and C. trachomatis. CLINICAL TRIALS REGISTRATION: NCT02870101.

A Desirability of Outcome Ranking Analysis of a Randomized Clinical Trial Comparing Seven Versus Fourteen Days of Antibiotics for Uncomplicated Gram-Negative Bloodstream Infection.

Background: Although a short course (7 days) of antibiotics has been demonstrated to be noninferior to a conventional course (14 days) in terms of mortality and infectious complications for patients with a Gram-negative bacterial bloodstream infection (GNB), it is unknown whether a shorter treatment duration can provide a better overall clinical outcome. Methods: We applied a bloodstream infection-specific desirability of outcome ranking (DOOR) analysis to the results of a previously completed, randomized controlled trial comparing short versus conventional course antibiotic therapy for hospitalized patients with uncomplicated GNB. We determined the probability that a randomly selected participant in the short course group would have a more desirable overall outcome than a participant in the conventional duration group. We performed (1) partial credit analyses allowing for calculated and variable weighting of DOOR ranks and (2) subgroup analyses to elucidate which patients may benefit the most from short durations of therapy. Results: For the 604 patients included in the original study (306 short course, 298 conventional course), the probability of having a more desirable outcome with a short course of antibiotics compared with a conventional course was 51.1% (95% confidence interval, 46.7% to 55.4%), indicating no significant difference. Partial credit analyses indicated that the DOOR results were similar across different patient preferences. Prespecified subgroup analyses using DOOR did not reveal significant differences between short and conventional courses of therapy. Conclusions: Both short and conventional durations of antibiotic therapy provide comparable clinical outcomes when using DOOR to consider benefits and risks of treatment options for GNB.

Patients' Experiences With Staphylococcus aureus and Gram-Negative Bacterial Bloodstream Infections: Results From Cognitive Interviews to Inform Assessment of Health-Related Quality of Life.

BACKGROUND: We previously conducted a concept elicitation study on the impact of Staphylococcus aureus and gram-negative bacterial bloodstream infections (SAB/GNB) on health-related quality of life (HRQoL) from the patient's perspective and found significant impacts on HRQoL, particularly in the physical and functional domains. Using this information and following guidance on the development of patient-reported outcome (PRO) measures, we determined which combination of measures and items (ie, specific questions) would be most appropriate in a survey assessing HRQoL in bloodstream infections. METHODS: We selected a variety of measures/items from the Patient-Reported Outcomes Measurement Information System (PROMIS) representing different domains. We purposefully sampled patients ~6-12 weeks post-SAB/GNB and conducted 2 rounds of cognitive interviews to refine the survey by exploring patients' understanding of items and answer selection as well as relevance for capturing HRQoL. RESULTS: We interviewed 17 SAB/GNB patients. Based on the first round of cognitive interviews (n = 10), we revised the survey. After round 2 of cognitive interviewing (n = 7), we finalized the survey to include 10 different PROMIS short forms/measures of the most salient HRQoL domains and 2 adapted questions (41 items total) that were found to adequately capture HRQoL. CONCLUSIONS: We developed a survey from well-established PRO measures that captures what matters most to SAB/GNB patients as they recover. This survey, uniquely tailored to bloodstream infections, can be used to assess these meaningful, important HRQoL outcomes in clinical trials and in patient care. Engaging patients is crucial to developing treatments for bloodstream infections.

Analytical Evaluation of the Abbott RealTime CT/NG Assay for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Rectal and Pharyngeal Swabs.

Chlamydia trachomatis and Neisseria gonorrhoeae infections in the rectum and pharynx are important extragenital reservoirs of infection. Few assays approved by the US Food and Drug Administration are commercially available to diagnose pharyngeal or rectal infections. The current study reports on the analytical performance of the Abbott RealTime CT/NG assay, including the limit of detection, inclusivity, and analytical specificity for C. trachomatis and N. gonorrhoeae in rectal and pharyngeal specimens. The limit of detection was performed using known concentrations of organisms, elementary bodies per milliliter (EB/mL) for C. trachomatis and colony-forming units per milliliter (CFU/mL) for N. gonorrhoeae, in clinical rectal and pharyngeal swab matrices. Inclusivity was performed against 12 serovars of C. trachomatis and seven strains of N. gonorrhoeae. The analytical specificity was performed using 28 different bacteria and viruses. The limit of detection for C. trachomatis was 2.56 EB/mL in pharyngeal specimens and 12.8 EB/mL in rectal specimens. The limit of detection for N. gonorrhoeae was 0.0256 CFU/mL for both pharyngeal and rectal specimens. The inclusivity and analytical specificity were 100% for both rectal and pharyngeal specimens. These analytical performance data demonstrate that the Abbott CT/NG RealTime assay is an accurate, sensitive, and specific assay in rectal and pharyngeal specimens, supporting the potential of the assay for detection of rectal and pharyngeal C. trachomatis and N. gonorrhoeae infections.

PqsE functions independently of PqsR-Pseudomonas quinolone signal and enhances the rhl quorum-sensing system.

Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute and chronic infections in immunocompromised individuals. This gram-negative bacterium produces a battery of virulence factors that allow it to infect and survive in many different hostile environments. The control of many of these virulence factors falls under the influence of one of three P. aeruginosa cell-to-cell signaling systems. The focus of this study, the quinolone signaling system, functions through the Pseudomonas quinolone signal (PQS), previously identified as 2-heptyl-3-hydroxy-4-quinolone. This signal binds to and activates the LysR-type transcriptional regulator PqsR (also known as MvfR), which in turn induces the expression of the pqsABCDE operon. The first four genes of this operon are required for PQS synthesis, but the fifth gene, pqsE, is not. The function of the pqsE gene is not known, but it is required for the production of multiple PQS-controlled virulence factors and for virulence in multiple models of infection. In this report, we show that PqsE can activate PQS-controlled genes in the absence of PqsR and PQS. Our data also suggest that the regulatory activity of PqsE requires RhlR and indicate that a pqsE mutant can be complemented for pyocyanin production by a large excess of exogenous N-butyryl homoserine lactone (C4-HSL). Finally, we show that PqsE enhances the ability of Escherichia coli expressing RhlR to respond to C4-HSL. Overall, our data lead us to conclude that PqsE functions as a regulator that is independent of PqsR and PQS but dependent on the rhl quorum-sensing system.

Telemonitoring in chronic obstructive airway disease and adult patients with cystic fibrosis.

We compared the use of telemonitoring in patients with chronic obstructive pulmonary disease (COPD) and adult patients with cystic fibrosis (CF). Seventy patients (51 CF and 19 COPD) were enrolled in two studies of six months' duration. Patients used a personal data assistant (PDA) attached to a spirometer to score symptoms and to perform daily spirometry. Criteria for diagnosis of exacerbations of COPD and CF were pre-defined. When exacerbations were detected, patients were offered treatment according to a pre-designed protocol. Thirty-two (63%) CF patients and one (5%) COPD patient withdrew from the studies due to lack of adherence to daily recording. For those who remained in the study, COPD patients recorded more study days (139) than CF patients (113), P = 0.03. The median number of exacerbations detected during the study was greater in COPD than in CF patients, although this was not significant. The median number of device-detected exacerbations in the COPD group was significantly greater than in the CF group, P = 0.024. When compared to a parallel period in the previous year, the number of hospitalisations for COPD exacerbations was reduced, whereas the number of intravenous antibiotics in CF patients did not differ. Adherence to telemonitoring was much greater for COPD than CF patients and the results appear to be more favourable for COPD patients than for CF patients.

Real-time, once-daily monitoring of symptoms and FEV in cystic fibrosis patients--a feasibility study using a novel device.

BACKGROUND AND AIMS: We investigated feasibility and value of a real-time electronic monitoring system adapted for early detection of cystic fibrosis (CF) pulmonary exacerbations (P Exs). METHODS: This was a 6-month prospective study. Patients recorded once daily their symptom score and spirometry using an electronic diary. The data were sent daily to the research team in real time. P Ex was considered to be present when change in symptoms and lung function values met a preset criteria. Number of P Exs during the study was compared with a parallel period of the previous and of the following years. RESULTS: Only 19 patients (37.2%) completed recording that could be evaluated. A total of 53 P Exs were identified, 26 (49.0%) of which needed intravenous (IV) antibiotics. The number of total P Exs in the study year did not differ from the previous or the following year, but the number of courses of oral antibiotics was greater than those given during the previous year. CONCLUSION: Remote daily monitoring of symptoms and spirometry had a poor uptake among CF patients. For those who completed the study, this method early detected P Exs that were treated with oral antibiotics that might otherwise required IV antibiotics.