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.

The Incidence of Pelvic and Low Back Pain in Patients with Pelvic Organ Prolapse.

INTRODUCTION AND HYPOTHESIS: To define the prevalence and incidence of pelvic/low back pain in patients with pelvic organ prolapse (POP). METHODS: Patients presenting for POP to three urogynecology centers in the US, UK, and Chile were enrolled in an IRB-approved cross-sectional study assessing pain, GU, GI and sexual function symptoms. For prevalence, symptoms were noted as present if the participant recorded the symptom and reported the degree of bother as "somewhat," "a moderate amount," or "a lot." For incidence, participants were queried if the symptom's onset concurred with the POP. We also queried if they perceived the symptom was worsened by their POP. RESULTS: Two hundred five participants were recruited: 100 from the US, 46 from the UK, and 59 from Chile. One US participant was excluded due a missing examination. The prevalence of pelvic pain was 42%. Seventy-three percent of these participants reported the onset of pelvic pain coinciding with prolapse onset, and 81% endorsed worsening pelvic pain with POP. The prevalence of low back pain was 46%, with 30% reporting the onset coincided with the onset of POP and 44% responded that prolapse worsened their pain. CONCLUSION: A higher proportion of participants than expected endorsed pelvic/low back pain. Among patients with pelvic pain, the majority experienced symptom onset with POP onset and a worsening of pain with POP. While roughly half of participants reported low back pain; a minority correlated this to their POP. These findings highlight a high incidence of pelvic pain, challenging the perception of POP as a painless condition.

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.

A Cost-Effectiveness Analysis of Post-Void Residual Bladder Scan Thresholds in the Postoperative Setting.

INTRODUCTION AND HYPOTHESIS: To identify the optimal cost-effectiveness threshold of post-void residual (PVR) by bladder scan in postoperative urogynecologic patients. METHODS: A cost-effectiveness analysis was performed as a secondary analysis of a previously published study of patients undergoing urogynecologic procedures with planned voiding trials, setting thresholds for postoperative PVR bladder scan volumes at 100 ml, 150 ml, and 200 ml. Patient-based scenarios were modeled for ambulatory office or emergency department (ED) resource utilization and to determine the cost-effectiveness of each threshold. Costs were obtained from a southeastern academic medical center, only utilizing direct medical costs and hospital costs, not including societal costs. Quality-adjusted life years (QALY's) were used as health outcomes determining the incremental cost-effectiveness ratio (ICER). RESULTS: A total of 151 patients from the original study were included. A willingness to pay threshold of $100,000 per QALY was assumed. A PVR of 100 ml exceeded this at $373,824. A PVR threshold of 150 ml was dominant (-$1,211,716), while minimizing ED visits for postoperative urinary retention (POUR) and unnecessary clinic appointments. While a PVR of 200 ml appeared a cost-effective strategy (-$488,389), there was increased ED utilization and under-detection of postoperative urinary retention (POUR). CONCLUSION: A PVR threshold of 100 ml created a healthcare system burden due to increased office voiding trials. Both PVR thresholds of 150 ml and 200 ml were cost-effective strategies; however, ED utilization for POUR increased with 200 ml. Utilizing 150 ml as the PVR cut-off proved the most cost-effective strategy, avoiding POUR under-detection and undue health costs.

Can We Trust the Math? Correlation of Objective Postvoid Residual With Calculated Subtraction Postvoid Residual.

OBJECTIVE: The aim of the study was to determine the accuracy of postvoid residual (PVR) by subtraction as compared with objective measurement by bladder scan or catheterization. METHODS: This is a secondary analysis of postoperative patients who underwent avoiding trial by retrograde bladder instillation. Fill volume, spontaneous voided volume, and PVR were objectively measured; PVR was also calculated. Pearson correlation compared PVR by subtraction versus objective measurement. We then defined postoperative urinary retention (POUR) at 3 different PVR values (100 mL, 150 mL, and 200 mL) to compare the sensitivity, specificity, and positive and negative predictive values of subtraction for detecting urinary retention at these 3 thresholds. RESULTS: Data were available for 155 patients after urogynecologic surgery. Median PVR by objective measurement was 46 mL (interquartile range = 11-146 mL). Median calculated PVR by subtraction was 10 mL (interquartile range = 0-100 mL). Objective measure and subtraction PVR values were strongly correlated (Pearson coefficient = 0.78, P < 0.001). Using a threshold of 200 mL to define POUR resulted in the highest negative predictive value and the lowest absolute number of both false negatives and false positives. Even using this threshold, 11 (48%) of 23 women with POUR by measurement were misclassified as not having POUR when ascertained by subtraction. CONCLUSIONS: Although subtraction PVR correlates well with objective PVR measurement, almost half of women with a PVR volume of greater than 200 mL by objective measurement are miscategorized as voiding normally by subtraction PVR. Based on these findings, reliance on objective PVR measurement in postoperative patients is preferable to subtraction PVR.

The effect of preoperative phenazopyridine on short-term urinary retention following urogynecologic surgery.

INTRODUCTION AND HYPOTHESIS: Previous studies have found that administration of phenazopyridine decreased short-term urinary retention following surgery but other more recent trials have shown mixed results. This study sought to investigate the potential benefit of preoperative administration of oral phenazopyridine in relation to the prevention of short-term urinary retention following urogynecologic surgery. METHODS: This is a retrospective cohort study of a convenience sample of women undergoing urogynecologic surgery from June 2016 to March 2019. Following surgery, subjects underwent a standardized retrograde voiding trial. The data had previously been gathered from a prior prospective trial at our institution (Kesty et al. Int Urogynecol J 31(9):1899-1905, 11). Chart review was performed to determine whether patients that received 200 mg of preoperative oral phenazopyridine to better visualize ureteral efflux during cystourethroscopy were more or less likely to pass their postoperative voiding trial. Bivariate statistical analysis was performed as well as a multivariate logistic regression model. RESULTS: A total of 165 subjects were included in the final analysis; 100 who did not receive preoperative phenazopyridine and 65 who did receive phenazopyridine. There was no statistical difference between voiding trial pass rates following urogynecologic surgery between those who did not receive preoperative phenazopyridine compared to those who did [77% (77/100) and 82% (53/65), respectively, p = 0.37)]. The multivariate logistic regression model demonstrated no difference in postoperative voiding trial pass rates among those who received preoperative phenazopyridine compared to those who did not (OR 1.7, 95% CI: 0.53, 5.8). CONCLUSIONS: Preoperative administration of oral phenazopyridine does not decrease short-term urinary retention following urogynecologic surgery.

Novel Lytic Enzyme of Prophage Origin from Clostridium botulinum E3 Strain Alaska E43 with Bactericidal Activity against Clostridial Cells.

Clostridium botulinum is a Gram-positive, anaerobic, spore-forming bacterium capable of producing botulinum toxin and responsible for botulism of humans and animals. Phage-encoded enzymes called endolysins, which can lyse bacteria when exposed externally, have potential as agents to combat bacteria of the genus Clostridium. Bioinformatics analysis revealed in the genomes of several Clostridium species genes encoding putative N-acetylmuramoyl-l-alanine amidases with anti-clostridial potential. One such enzyme, designated as LysB (224-aa), from the prophage of C. botulinum E3 strain Alaska E43 was chosen for further analysis. The recombinant 27,726 Da protein was expressed and purified from E. coli Tuner(DE3) with a yield of 37.5 mg per 1 L of cell culture. Size-exclusion chromatography and analytical ultracentrifugation experiments showed that the protein is dimeric in solution. Bioinformatics analysis and results of site-directed mutagenesis studies imply that five residues, namely H25, Y54, H126, S132, and C134, form the catalytic center of the enzyme. Twelve other residues, namely M13, H43, N47, G48, W49, A50, L73, A75, H76, Q78, N81, and Y182, were predicted to be involved in anchoring the protein to the lipoteichoic acid, a significant component of the Gram-positive bacterial cell wall. The LysB enzyme demonstrated lytic activity against bacteria belonging to the genera Clostridium, Bacillus, Staphylococcus, and Deinococcus, but did not lyse Gram-negative bacteria. Optimal lytic activity of LysB occurred between pH 4.0 and 7.5 in the absence of NaCl. This work presents the first characterization of an endolysin derived from a C. botulinum Group II prophage, which can potentially be used to control this important pathogen.

Update in Transvaginal Grafts: The Role of Lightweight Meshes, Biologics, and Hybrid Grafts in Pelvic Organ Prolapse Surgery.

Transvaginal mesh/grafts have been popularized over the past 20 years in an attempt to improve the longevity of traditional vaginal pelvic organ prolapse (POP) surgery. Several national bodies have concluded that the proposed benefits of mesh/graft implantation are outweighed by the significant increase in surgery complications related to these products. As a consequence mesh products for vaginal POP surgery have been withdrawn from use in many countries. This article is a narrative review of newer mesh and graft products including lightweight polypropylene mesh products, biological grafts, hybrid grafts, and tissue engineered grafts.

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.

Mental health among clinicians: what do we know and what can we do?

Mental health and mental health disorders among clinicians remain a taboo, despite increasing evidence showing the direct impact on medical teams and patient care. This editorial is aimed at increasing awareness of mental issues amongst healthcare professionals, identifying perceived barriers to seeking help, and suggesting ways in which to seek help. Mental health disorders, including anxiety and depression, are prevalent from medical school, leading to increased burnout and suicide risks at later stages of a clinician's career. There is often a reluctance to seek help, particularly amongst the surgical specialties, caused by self-criticism, lack of convenient access and the potential negative impact on medical licensure. This editorial has been written in loving memory of our colleague, friend and board member Dr. Nikolaus Veit-Rubin, who sadly passed away at the beginning of the year. It is written in the hope of highlighting the importance of maintaining mental wellbeing amongst the medical team, supporting help-seeking behaviour and changing attitudes toward mental health disorders amongst clinicians.

Treatment outcomes of overactive bladder with combined therapies of botulinum toxin injections and oral agents.

OBJECTIVE: Treatment options for refractory overactive bladder (OAB) following behavioral modifications and oral OAB medications remain limited. Up to 33% of women fail botulinum toxin injections (Amundsen et al. Eur Urol. 74(1):66-73, 7). This study evaluates the effectiveness of combining oral OAB agents with botulinum toxin in subjects who failed botulinum toxin therapy alone. METHODS: This is a retrospective observational study. Eligible women were those who received botulinum toxin injections for OAB between 2013 and 2018 at one academic institution. Women were given the option of oral medications as add-back therapy following failed treatment with botulinum toxin alone. Treatment response was a subjective outcome, with subjects reporting being satisfied or unsatisfied. The primary outcome was the proportion of subjects who achieved satisfactory treatment response with the combination of oral OAB medications and botulinum toxin injections. A subanalysis was performed to further investigate any risk factors associated with poor response to combination treatment. Variables were analyzed using chi-squared or Fisher's exact test and Student's t-test or Mann-Whitney U when appropriate. RESULTS: A total of 107 charts were reviewed. Forty-five (48%) women failed botulinum toxin alone as a treatment; 26 (29%) elected to try one or more oral OAB medications. Of the 26 women who received the combination treatment, 17 (65%) reported satisfaction and 9 (35%) remained unsatisfied. Risk factors associated with treatment failure were not identified. CONCLUSION: This is an initial report on adding back oral OAB meds to patients who have failed botulinum toxin injections suggesting there may be a role for add-back oral OAB medications.

Genital Hiatus Size as a Predictor of Progression of Pelvic Organ Prolapse.

OBJECTIVE: This study aimed to determine if genital hiatus (GH) size is a predictor of worsening pelvic organ prolapse and a preference for a therapeutic intervention in women with pelvic organ prolapse who opt for expectant management over therapeutic intervention at their initial encounter. METHODS: This was a retrospective cohort study analyzing the GH size of women who opted for expectant management in the initial treatment of pelvic organ prolapse at one academic institution from 2002 to 2015. Participants were divided into 2 groups: (1) large GH was defined as ≥4 cm and (2) normal GH was defined as <4 cm. The primary outcome was women opting for therapeutic intervention for their prolapse at a later visit, defined as pessary insertion or surgical intervention. Secondary measures evaluated GH as a predictor of worsening anatomy or symptoms. RESULTS: One hundred eleven participants were enrolled. Fifty-two women had a large GH, and 59 women had a normal GH. Median length of follow-up was 24 months (range, 6-110 months). Of the 52 with a large GH, 22 (42%) opted for intervention; of the 59 women with a normal GH, 16 (27%) opted for intervention. There was no statistically significant difference between groups in the number who eventually chose intervention (P = 0.09). There was no difference in secondary outcomes between groups with respect to worsening bother, worsening pelvic organ prolapse quantification stage, or an increase in the prolapse leading edge of ≥2 cm. CONCLUSIONS: Women with a large GH, when compared with those with a normal GH, were not more likely to choose intervention over continued observation.

Factors affecting patient choice for continued observation versus intervention for pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: To analyze the reasons for eventual choice of a therapeutic intervention in subjects who initially chose observation for bothersome pelvic organ prolapse (POP) over therapeutic intervention at their first urogynecology clinic visit. METHODS: This is a retrospective cohort study of women with bothersome POP who initially chose observation over therapeutic intervention at one institution from 2002 to 2015. Subjects were followed over time with sequential pelvic organ prolapse quantification examinations (POP-Q) and assessments of symptoms and bother utilizing non-validated standard questions. Subjects were divided into two groups: (1) those who chose continued observation versus (2) those who chose therapeutic intervention with either pessary or surgery. Demographic information, POP-Q examinations, and POP symptoms and bother were collected. We analyzed which clinical variables influenced patient decision to elect for therapeutic intervention. RESULTS: A total of 111 subjects were enrolled. The distribution of initial POP-Q stage was: stage 2 = 54%; stage 3 = 45%; stage 4 = 1%. Median follow-up was 24 months (range 6 and 110 months). At their last recorded visit, 73 subjects (66%) continued observation and 38 subjects (34%) chose pessary or surgical intervention. We investigated clinical factors for choosing intervention. Increase in POP symptom bother was the only variable that remained significant in determining patient choice of a therapeutic intervention (p < 0.001) after confounding factors were controlled for using multivariate regression analysis. CONCLUSION: In subjects with bothersome POP who initially choose observation and subsequently elect to pursue a therapeutic intervention, worsening symptom bother is the most important factor.