Pseudomonas aeruginosa ventricular assist device infections: findings from ineffective phage therapies in five cases

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.

Designing and analyzing studies of coronavirus disease 2019 and post-acute sequelae of severe acute respiratory syndrome coronavirus 2 among immunocompromised individuals

Observational studies of coronavirus disease 2019 (COVID-19) among transplant candidates and recipients remain important as immunocompromised patients formed a very small proportion of patients included in COVID-19 trials and large database analyses. We discuss methods that have been used in such analyses to evaluate the impact of vaccination on the risk of symptomatic COVID-19 in such patients and on the probability of developing post-acute sequelae of severe acute respiratory syndrome coronavirus 2 after the onset of infection. We also propose future directions for research and discuss the methods that will be useful to conduct such investigations. The study design and analytical issues that we consider have the potential to be helpful not only for COVID-19 research but also for other infections as well.

Cardiac allograft vasculopathy in heart transplant recipients from hepatitis C viremic donors

BACKGROUND

Recent studies suggest the transplantation of Hepatitis C (HCV) hearts from viremic donors is associated with comparable 1 year survival to nonviremic donors. Though HCV viremia is a known risk factor for accelerated atherosclerosis, data on cardiac allograft vasculopathy (CAV) outcomes are limited. We compared the incidence of CAV in heart transplant recipients from HCV viremic donors (nucleic acid amplification test positive; NAT+) compared to non-HCV infected donors (NAT-).

METHODS

We retrospectively reviewed annual coronary angiograms with intravascular ultrasound from April 2017 to August 2020 at two large cardiac transplant centers. CAV was graded according to ISHLT guidelines. Maximal intimal thickness (MIT) ≥ 0.5 mm was considered significant for subclinical disease.

RESULTS

Among 270 heart transplant recipients (mean age 54; 77% male), 62 patients were transplanted from NAT+ donors. CAV ≥ grade 1 was present in 8.8% of the NAT+ versus 16.8% of the NAT- group at 1 year, 20% versus 28.8% at 2 years, and 33.3% versus 41.5% at 3 years. After adjusting for donor age, donor smoking history, recipient BMI, recipient, hypertension, and recipient diabetes, NAT+ status did not confer increased risk of CAV (HR.80; 95% CI.45-1.40, p = 0.43) or subclinical IVUS disease (HR.87; 95% CI.58-1.30, p = 0.49). Additionally, there was no difference in the presence of rapidly progressive lesions on IVUS.

CONCLUSION

Our data show that NAT+ donors conferred no increased risk for early CAV or subclinical IVUS disease following transplantation in a cohort of heart transplant patients who were treated for HCV, suggesting the short-term safety of this strategy to maximize the pool of available donor hearts.

A simple solid media assay for detection of synergy between bacteriophages and antibiotics

The emergence of antibiotic-resistant bacteria (ARB) has necessitated the development of alternative therapies to deal with this global threat. Bacteriophages (viruses that target bacteria) that kill ARB are one such alternative. Although phages have been used clinically for decades with inconsistent results, a number of recent advances in phage selection, propagation, and purification have enabled a reevaluation of their utility in contemporary clinical medicine. In most phage therapy cases, phages are administered in combination with antibiotics to ensure that patients receive the standard-of-care treatment. Some phages may work cooperatively with antibiotics to eradicate ARB, as often determined using non-standardized broth assays. We sought to develop a solid media-based assay to assess cooperativity between antibiotics and phages to offer a standardized platform for such testing. We modeled the interactions that occur between antibiotics and phages on solid medium to measure additive, antagonistic, and synergistic interactions. We then tested the method using different bacterial isolates and identified a number of isolates where synergistic interactions were identified. These interactions were not dependent on the specific organism, phage family, or antibiotic used. A priori susceptibility to the antibiotic or the specific phage were not requirements to observe synergistic interactions. Our data also confirm the potential for the restoration of vancomycin to treat vancomycin-resistant Enterococcus (VRE) when used in combination with phages. Solid media assays for the detection of cooperative interactions between antibiotics and phages can be an accessible technique adopted by clinical laboratories to evaluate antibiotic and phage choices in phage therapy.IMPORTANCEBacteriophages have become an important alternative treatment for individuals with life-threatening antibiotic-resistant bacteria (ARB) infections. Because antibiotics represent the standard-of-care for treatment of ARB, antibiotics and phages often are delivered together without evidence that they work cooperatively. Testing for cooperativity can be difficult due to the equipment necessary and a lack of standardized means for performing the testing in liquid medium. We developed an assay using solid medium to identify interactions between antibiotics and phages for gram-positive and gram-negative bacteria. We modeled the interactions between antibiotics and phages on solid medium, and then tested multiple replicates of vancomycin-resistant Enterococcus (VRE) and Stenotrophomonas in the assay. For each organism, we identified synergy between different phage and antibiotic combinations. The development of this solid media assay for assessing synergy between phages and antibiotics will better inform the use of these combinations in the treatment of ARB infections.

Phage resistance in Klebsiella pneumoniae and bidirectional effects impacting antibiotic susceptibility

OBJECTIVES

Bacteriophage (phage) therapy is a promising anti-infective option to combat antimicrobial resistance. However, the clinical utilization of phage therapy has been severely compromised by the potential emergence of phage resistance. Although certain phage resistance mechanisms can restore bacterial susceptibility to certain antibiotics, a lack of knowledge of phage resistance mechanisms hinders optimal use of phages and their combination with antibiotics.

METHODS

Genome-wide transposon screening was performed with a mutant library of Klebsiella pneumoniae MKP103 to identify phage pKMKP103_1-resistant mutants. Phage-resistant phenotypes were evaluated by time-kill kinetics and efficiency of plating assays. Phage resistance mechanisms were investigated with adsorption, one-step growth, and mutation frequency assays. Antibiotic susceptibility was determined with broth microdilution and population analysis profiles.

RESULTS

We observed a repertoire of phage resistance mechanisms in K pneumoniae, such as disruption of phage binding (fhuA::Tn and tonB::Tn), extension of the phage latent period (mnmE::Tn and rpoN::Tn), and increased mutation frequency (mutS::Tn and mutL::Tn). Notably, in contrast to the prevailing view that phage resistance re-sensitizes antibiotic-resistant bacteria, we observed a bidirectional steering effect on bacterial antibiotic susceptibility. Specifically, rpoN::Tn increased susceptibility to colistin while mutS::Tn and mutL::Tn increased resistance to rifampicin and colistin.

DISCUSSION

Our findings demonstrate that K pneumoniae employs multiple strategies to overcome phage infection, which may result in enhanced or reduced antibiotic susceptibility. Mechanism-guided phage steering should be incorporated into phage therapy to better inform clinical decisions on phage-antibiotic combinations.

Wait Time Advantage for Transplant Candidates With HIV Who Accept Kidneys From Donors With HIV Under the HOPE Act

BACKGROUND

Kidney transplant (KT) candidates with HIV face higher mortality on the waitlist compared with candidates without HIV. Because the HIV Organ Policy Equity (HOPE) Act has expanded the donor pool to allow donors with HIV (D + ), it is crucial to understand whether this has impacted transplant rates for this population.

METHODS

Using a linkage between the HOPE in Action trial (NCT03500315) and Scientific Registry of Transplant Recipients, we identified 324 candidates listed for D + kidneys (HOPE) compared with 46 025 candidates not listed for D + kidneys (non-HOPE) at the same centers between April 26, 2018, and May 24, 2022. We characterized KT rate, KT type (D + , false-positive [FP; donor with false-positive HIV testing], D - [donor without HIV], living donor [LD]) and quantified the association between HOPE enrollment and KT rate using multivariable Cox regression with center-level clustering; HOPE was a time-varying exposure.

RESULTS

HOPE candidates were more likely male individuals (79% versus 62%), Black (73% versus 35%), and publicly insured (71% versus 52%; P  < 0.001). Within 4.5 y, 70% of HOPE candidates received a KT (41% D + , 34% D - , 20% FP, 4% LD) versus 43% of non-HOPE candidates (74% D - , 26% LD). Conversely, 22% of HOPE candidates versus 39% of non-HOPE candidates died or were removed from the waitlist. Median KT wait time was 10.3 mo for HOPE versus 60.8 mo for non-HOPE candidates ( P  < 0.001). After adjustment, HOPE candidates had a 3.30-fold higher KT rate (adjusted hazard ratio = 3.30, 95% confidence interval, 2.14-5.10; P  < 0.001).

CONCLUSIONS

Listing for D + kidneys within HOPE trials was associated with a higher KT rate and shorter wait time, supporting the expansion of this practice for candidates with HIV.

Using HCV-viremic organs for lung transplantation does not confer higher rejection rates compared to HCV-negative organs

BACKGROUND

National data demonstrate that hepatitis C virus (HCV)-infected organ donors are increasingly being used in the US, including for lung transplantation. We aimed to assess whether there were any differences in the acute or chronic rejection rates at 1 year following lung transplantation from HCV-viremic versus uninfected donors.

METHODS

We retrospectively reviewed all lung transplant recipients at our institution from April 1, 2017 to October 1, 2020 and then assessed various outcomes between those who received a transplant from HCV-viremic donors versus HCV-negative donors. Primary outcome was to determine if there was a higher incidence of acute and/or chronic allograft rejection when using HCV NAT+ lung donation. We carried out univariate and multivariate analyses.

RESULTS

We transplanted 135 patients during the study period, including 18 from HCV-viremic donors. Standard induction therapy with basiliximab and maintenance triple drug immunosuppression was utilized per UC San Diego protocol. All 17 patients receiving HCV-viremic organs developed acute HCV infection and were treated in the postoperative period with 12 weeks of direct acting antivirals (DAA). HCV genotypes included 1, 2, and 3. DAA used included glecaprevir/pibrentasvir (12), sofosbuvir/velpatasvir (1), and ledipasvir/sofosbuvir (2) with drug choice determined by patient's medical insurance coverage. Sustained virological response at 12 weeks after end of DAA therapy (SVR12), indicative of a cure, was achieved in all (100%) recipients. No recipient had a serious adverse event related to HCV infection. The lung transplant recipient (LTR) HCV-viremic donors had lower rates of clinically significant rejection (5.9% vs. 11% LTR HCV-nonviremic donors), and no chronic lung allograft dysfunction at 1 year (vs. 5.9% LTR HCV-nonviremic donors). One-year survival was 100% in the LTR HCV-viremic donors compared to 95.8% in the LTR HCV-nonviremic donors.

CONCLUSIONS

We demonstrate the feasibility and success of using HCV NAT + donors with excellent results and without a higher incidence of rejection. Longer term follow-up and a larger sample size are needed to allow this to be a more widely accepted practice for lung transplant programs and payors.

Difference in immunosuppressant dose requirement when transitioning to isavuconazole from other azoles in thoracic transplant recipients

The triazole antifungal isavuconazole (ISAVU) is used for prevention and treatment of fungal infections in solid organ transplant (SOT). SOT recipients commonly need to transition from one azole to another due to breakthrough infection, toxicity, or other reasons. The purpose of our study was to evaluate the effect of ISAVU on immunosuppressant concentrations in thoracic transplant recipients when ISAVU was started de novo or transitioned from another azole. We conducted a single-center retrospective cohort study including 68 patients (51 lung, 14 heart, and 3 heart/lung transplant). Concentration to dosage ratios (C/D) of immunosuppressants were assessed at baseline, day 3, and weekly for 9 weeks. When starting ISAVU de novo, we observed a temporary doubling of tacrolimus exposure. Cyclosporine and sirolimus required dose decreases. Tacrolimus C/D increased by 110% at day 3 in patients started on ISAVU de novo then returned to baseline C/D ± 17% weeks 2-9 (n = 8). One cyclosporine patient started on ISAVU de novo had variable C/D, and C/D increased by 219% ± 72% in 2 sirolimus patients. When transitioning from other azoles, tacrolimus and cyclosporine required about twice the initial dose. After week 1, tacrolimus C/D decreased by 53% ± 6% in patients transitioned from posaconazole (n = 33), voriconazole (n = 14), or fluconazole (n = 2). Cyclosporine C/D decreased by 45% ± 16% in patients transitioning from other azoles (posaconazole [n = 2], voriconazole [n = 2], fluconazole [n = 1]). Sirolimus C/D decreased by 73% ± 13% in patients transitioned from posaconazole (n = 7). Aside from the initial loading phase, ISAVU had a lesser degree of interaction with immunosuppressants than other azoles in loading phase, ISAVU had a lesser degree of interaction with immunosuppressants than other azoles in adjustments for the 4-week period after initiating antifungal therapy with ISAVU or switching from another agent.

Population and risk assessment of sympatric pheasant species in Palas Valley, Pakistan

Abstract Pheasants are declining everywhere in the world and therefore updated information about their population and habitats are important for conservation and management. The present study was conducted in the Palas Valley, District Kohistan, Pakistan in late spring (May and June) 2020 and early spring (March and April) 2021 to assess the population and anthropogenic stress. The major focus was on three sympatric pheasant species, including Western Horned Tragopan (Tragopan melanocephalus), Himalayan Monal (Lophophorus impejanus), and Koklass Pheasant (Pucrasia macrolopha). We used the “Call Count Method” for the population assessment in the field, and a questionnaire survey was conducted to document the risk assessment of local residents of the valley. The population assessments revealed that the Koklass Pheasant is more adapted to increasing anthropogenic activities and its population appeared more or less similar as 22 years ago. In the past 22 years, Western Tragopan and Himalayan Monal have lost about 40–50% of their populations. Human interference in the form of illegal hunting, deforestation, and overgrazing was found to be common in the valley. The study concludes that the Palas Valley habitat is ideal for pheasant species; however, human interference in the form of urbanization, habitat fragmentation, illegal hunting, and deforestation is occurring at a rapid pace, causing havoc in the pheasant population.

Post-acute sequelae of COVID-19 in solid organ transplant recipients

BACKGROUND

Post-acute sequelae of coronavirus disease 2019 (COVID-19) (PASC), defined as prolonged symptoms following an episode of COVID-19, is not well-characterized in solid organ transplant recipients (SOTR). In this study, we aimed to assess the prevalence of PASC in SOTR, its descriptive characteristics, and associated risk factors.

METHODS

We retrospectively identified SOTRs with acute COVID-19 between June 1, 2020 and April 15, 2022, and abstracted demographic and medical history, characteristics of acute COVID-19 illness, and COVID-19 vaccination status. We defined PASC as ongoing/new symptoms present at 6 weeks or longer following acute COVID-19 diagnosis.

RESULTS

Among 208 SOTRs with acute COVID-19, 72 (35%) developed PASC. Common symptoms were respiratory symptoms (67%), headache (40%), and difficulty concentrating (10%). Severe acute COVID-19 disease and presence of respiratory symptoms were associated with higher odds of PASC in multivariable analyses, while receipt of at least one COVID-19 vaccination prior to transplantation was protective.

CONCLUSION

We found that PASC occurs in about a third of SOTRs with acute COVID-19 and has similar symptoms as described previously in immunocompetent hosts. Pre-transplant vaccination may be protective. Further prospective multicenter studies are needed.

Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at sqrt[s_{NN}]=200 GeV

The polarization of Λ and Λ[over ¯] hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at sqrt[s_{NN}]=200  GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild p_{T} dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagrees with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and p_{T} dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.

Phage Therapy in Lung Transplantation: Current Status and Future Possibilities

Patients with chronic lung disease and lung transplantation have high rates of colonization and infection from multidrug-resistant (MDR) organisms. This article summarizes the current state of knowledge regarding phage therapy in the setting of lung transplantation. Phage therapy has been used in several lung transplant candidates and recipients on a compassionate use basis targeting mostly MDR gram-negative infections and atypical mycobacterial infections with demonstrated clinical safety. Phage biodistribution given intravenously or via nebulization has not been extensively studied, though preliminary data are presented. Phage interacts with both the innate and adaptive immune system; current literature demonstrates the development of serum neutralization in some cases of phage therapy, although the clinical impact seems variable. A summary of current clinical trials involving patients with chronic lung disease is presented, though none are specifically targeting lung transplant candidates or recipients. In addition to treatment of active infections, a variety of clinical scenarios may benefit from phage therapy, and well-designed clinical trials involving this vulnerable patient population are needed: pre- or peritransplantation use of phage in the setting of MDR organism colonization may lead to waitlisting of candidates currently declined by many centers, along with potential reduction of waitlist mortality rates and posttransplant infections; phage may be used for biofilm-related bronchial stent infections; and, finally, there is a possibility that phage use can affect allograft function and chronic rejection.

HIV-Positive Liver Transplant Does not Alter the Latent Viral Reservoir in Recipients With Antiretroviral Therapy-Suppressed HIV

The latent viral reservoir (LVR) remains a major barrier to HIV-1 curative strategies. It is unknown whether receiving a liver transplant from a donor with HIV might lead to an increase in the LVR because the liver is a large lymphoid organ. We found no differences in intact provirus, defective provirus, or the ratio of intact to defective provirus between recipients with ART-suppressed HIV who received a liver from a donor with (n = 19) or without HIV (n = 10). All measures remained stable from baseline by 1 year posttransplant. These data demonstrate that the LVR is stable after liver transplantation in people with HIV. Clinical Trials Registration. NCT02602262 and NCT03734393.

A Retrospective, Observational Study of 12 Cases of Expanded-Access Customized Phage Therapy: Production, Characteristics, and Clinical Outcomes

BACKGROUND

Antimicrobial resistance (AMR) is undermining modern medicine, a problem compounded by bacterial adaptation to antibiotic pressures. Phages are viruses that infect bacteria. Their diversity and evolvability offer the prospect of their use as a therapeutic solution. Reported are outcomes of customized phage therapy for patients with difficult-to-treat antimicrobial resistant infections.

METHODS

We retrospectively assessed 12 cases of customized phage therapy from a phage production center. Phages were screened, purified, sequenced, characterized, and Food and Drug Administration-approved via the IND (investigational new drug) compassionate-care route. Outcomes were assessed as favorable or unfavorable by microbiologic and clinical standards. Infections were device-related or systemic. Other experiences such as time to treatment, antibiotic synergy, and immune responses were recorded.

RESULTS

Fifty requests for phage therapy were received. Customized phages were generated for 12 patients. After treatment, 42% (5/12) of cases showed bacterial eradication and 58% (7/12) showed clinical improvement, with two-thirds of all cases (66%) showing favorable responses. No major adverse reactions were observed. Antibiotic-phage synergy in vitro was observed in most cases. Immunological neutralization of phages was reported in 5 cases. Several cases were complicated by secondary infections. Complete characterization of the phages (morphology, genomics, and activity) and their production (methods, sterility, and endotoxin tests) are reported.

CONCLUSIONS

Customized phage production and therapy was safe and yielded favorable clinical or microbiological outcomes in two-thirds of cases. A center or pipeline dedicated to tailoring the phages against a patient's specific AMR bacterial infection may be a viable option where standard treatment has failed.

Study on the impact of exogenously applied methyl jasmonate concentrations on Solanum lycopersicum under low temperature stress

BACKGROUND

To decipher the capability of Methyl Jasmonate (MeJA) in resisting cold stress in Solanum lycopersicum assessment regarding various physiological parameters in response to diverse doses of MeJA was done. Low temperature (LT) were given to the plants with MeJA (J1C, J2C, J3C) or without MeJA (LT) application. MeJA in the form of foliar spray was given before stress, during stress and after stress. Three concentrations of MeJA were used under normal and LT stress conditions that includes of J1 (0.5 µM), J2 (10 µM), and J3 (15 µM).

RESULTS

Oxidative stress, growth characteristics, stress tolerance parameters, antioxidant response and photosynthetic parameters were investigated. In our current study we observed that oxidative stress markers declined by MeJA supplementation under cold stress conditions. MeJA boosted antioxidant enzyme activity along with photosynthetic parameters. The best concentration of MeJA was J2 based on results obtained. This is the first study related to MeJA best dose screening in Solanum lycopersicum under LT stress conditions.

CONCLUSION

The LT stress in the Solanum lycopersicum plant was reduced by MeJA. The adverse consequences of LT stress can be significantly attenuated by the J2 concentration of MeJA. So, the optimal concentration of MeJA supplied exogenously to LT stressed Solanum lycopersicum can be a smart strategy to mitigate harmful impact of LT stress on detox system and overall growth of plant.

Refractory Pseudomonas aeruginosa infections treated with phage PASA16: A compassionate use case series

BACKGROUND

A growing number of compassionate phage therapy cases were reported in the last decade, with a limited number of clinical trials conducted and few unsuccessful clinical trials reported. There is only a little evidence on the role of phages in refractory infections. Our objective here was to present the largest compassionate-use single-organism/phage case series in 16 patients with non-resolving Pseudomonas aeruginosa infections.

METHODS

We summarized clinical phage microbiology susceptibility data, administration protocol, clinical data, and outcomes of all cases treated with PASA16 phage. In all intravenous phage administrations, PASA16 phage was manufactured and provided pro bono by Adaptive Phage Therapeutics. PASA16 was administered intravenously, locally to infection site, or by topical use to 16 patients, with data available for 15 patients, mainly with osteoarticular and foreign-device-associated infections.

FINDINGS

A few minor side effects were noted, including elevated liver function enzymes and a transient reduction in white blood cell count. Good clinical outcome was documented in 13 out of 15 patients (86.6%). Two clinical failures were reported. The minimum therapy duration was 8 days with a once- to twice-daily regimen.

CONCLUSIONS

PASA16 with antibiotics was found to be relatively successful in patients for whom traditional treatment approaches have failed previously. Such pre-phase-1 cohorts can outline potential clinical protocols and facilitate the design of future trials.

FUNDING

The study was funded in part by The Israeli Science Foundation IPMP (ISF_1349/20), Rosetrees Trust (A2232), United States-Israel Binational Science Foundation (2017123), and the Milgrom Family Support Program.

A simple solid media assay for detection of synergy between bacteriophages and antibiotics

The emergence of antibiotic resistant bacteria (ARB) has necessitated the development of alternative therapies to deal with this global threat. Bacteriophages (viruses that target bacteria) that kill ARB are one such alternative. While phages have been used clinically for decades with inconsistent results, a number of recent advances in phage selection, propagation and purification have enabled a reevaluation of their utility in contemporary clinical medicine. In most phage therapy cases, phages are administered in combination with antibiotics to ensure that patients receive the standard-of-care treatment. Some phages may work cooperatively with antibiotics to eradicate ARB, as often determined using non-standardized broth assays. We sought to develop a solid media-based assay to assess cooperativity between antibiotics and phages to offer a standardized platform for such testing. We modeled the interactions that occur between antibiotics and phages on solid medium to measure additive, antagonistic, and synergistic interactions. We then tested the method using different bacterial isolates, and identified a number of isolates where synergistic interactions were identified. These interactions were not dependent on the specific organism, phage family, or antibiotic used. A priori susceptibility to the antibiotic or the specific phage were not requirements to observe synergistic interactions. Our data also confirm the potential for the restoration of vancomycin to treat Vancomycin Resistant Enterococcus (VRE) when used in combination with phages. Solid media assays for the detection of cooperative interactions between antibiotics and phages can be an accessible technique adopted by clinical laboratories to evaluate antibiotic and phage choices in phage therapy.

Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central ^{3}He+Au, d+Au and p+Au Collisions at sqrt[s_{NN}]=200 GeV

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200  GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

Melatonin Alters Innate Immune Function in Infants with Neonatal Encephalopathy

INTRODUCTION

Melatonin has been suggested an adjunctive therapy in neonatal encephalopathy (NE). Melatonin reduces oxidative stress and neutrophil activation; however, the immunological effects in NE have not been studied.

METHODS

Infants with NE and neonatal controls were prospectively recruited. Whole blood was sampled in the first week of life. Following endotoxin and or melatonin treatment, diurnal variation was measured by RT PCR for circadian rhythm genes (brain and Muscle Arnt-Like protein [BMAL1], circadian locomotor output cycles kaput [CLOCK], Nuclear Receptor Subfamily 1 Group D Member 2 [REV Erβ], and cryptochrome circadian clock [CRY]). Neutrophil and monocyte cell surface markers of activation CD11b, reactive oxygen intermediates (ROIs), and Toll-like receptor (TLR)-4 were also examined by flow cytometry in matching samples.

RESULTS

Serum and RNA samples from forty infants were included (controls n = 20; NE n = 20) over the first week of life. Melatonin reduced neutrophil CD11b and TLR-4 expression in response to LPS in infants with NE compared to controls. There were no differences in ROIs. BMAL1 and CLOCK baseline gene expression levels were similar. BMAL1 was significantly decreased with LPS stimulation in NE. There was no significant diurnal variation in melatonin, neutrophil, and monocyte function or circadian genes.

CONCLUSIONS

Melatonin alters immune function ex vivo in infants with NE. Infants with NE have altered immune circadian responses following LPS stimulation, which have potential for modulation.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}^{2}) in Au+Au Collisions at RHIC

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200  GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Therapeutic Potential of Intravenous Phage as Standalone Therapy for Recurrent Drug-Resistant Urinary Tract Infections

Recurrent urinary tract infections (rUTI) are common in kidney transplant recipients (KTR) and are associated with multidrug resistance and increased morbidity/mortality. Novel antibiotic alternatives to reduce UTI recurrence are critically needed. We describe a case of rUTI due to extended spectrum beta lactamase (ESBL) Klebsiella pneumoniae in a KTR that was treated successfully with 4 weeks of adjunctive intravenous bacteriophage therapy alone, without concomitant antibiotics, and with no recurrence in a year of follow-up.

Development of Host Immune Response to Bacteriophage in a Lung Transplant Recipient on Adjunctive Phage Therapy for a Multidrug-Resistant Pneumonia

Bacteriophage therapy is the use of viruses to kill bacteria for the treatment of antibiotic-resistant infections. Little is known about the human immune response following phage therapy. We report the development of phage-specific CD4 T cells alongside rising phage-specific immunoglobulin G and neutralizing antibodies in response to adjunctive bacteriophage therapy used to treat a multidrug-resistant Pseudomonas aeruginosa pneumonia in a lung transplant recipient. Clinically, treatment was considered a success despite the development phage-specific immune responses.

783. Lung Transplantation for COVID-19-Associated Lung Injury (CALI): An International Registry

Background

SARS-CoV-2 can result in a range of infections from asymptomatic disease to progressive COVID-19 and death. In some pts with CALI, lung transplantation (LTx) may be lifesaving. Up to 10% of LTx in the US is currently for pts with CALI. Understanding the characteristics and outcomes of these pts is critical.

Methods

A open-access electronic registry was established to collect de-identified data from pts who have undergone LTx for CALI from centers globally. The study was IRB approved at Northwestern with a wavier for consent (no PHI is collected sites could submit data about pre-Tx, peri-Tx and post-Tx course). Follow-up for 1-yr post-LTx was collected.

Results

To date, 89 pts with complete day 30 post-LTx data have been entered into the registry. Pt demographics and pre-Tx status are shown in Table 1. 3 pts required oxygen prior to COVID-19. Most sites required neg PCR tests prior to listing (11 (12.4%) required no - PCRs, 11 (12.4%) required 1 and 61 (68.5%) required 2). LTx occurred 137 days post-infection and none developed COVID-19 in the first 30 d; 4 were given monoclonal antibodies post-tx. Post-tx ICU LOS averaged 24.5 d with total post-tx hospitalization of 37.6 d (See Table 2). Most experienced infectious and non-infectious morbidity. Most (47.8%) required an additional 30 days of rehab. 2 pts died within 30 days due to sepsis and anoxia. 5 died between day 30 and 90 and an additional 12 died between day 90 and 365.

Conclusion

The contribution of cases to this international registry is ongoing. While outcomes of LTx for CALI are generally good, patients experience prolonged post-transplant hospitalization, rehabilitation and significant morbidity and infections are common.

Disclosures

Michael G. Ison, MD MS, GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support Saima Aslam, MD, Armata: Grant/Research Support|BioMx: Advisor/Consultant|Contrafect: Grant/Research Support|Gilead: Honoraria|Merck: Honoraria|Phico: Advisor/Consultant.

Role of bacteriophage therapy for resistant infections in transplant recipients

PURPOSE OF REVIEW

Multidrug-resistant organisms (MDROs) are prevalent in transplant recipients and associated with poor outcomes. We review recent cases of phage therapy used to treat recalcitrant infections in transplant recipients and explore the future role of such therapy in this setting.

RECENT FINDINGS

Individual case reports and small case series suggest possible efficacy of phage therapy for the treatment of MDRO infections in pre and posttransplant patients. Importantly, there have been no serious safety concerns in the reported cases that we reviewed. There are no applicable randomized controlled trials (RCTs) to better guide phage therapy at this time.

SUMMARY

Given the safety and possibility of successful salvage therapy of MDRO infections using bacteriophages, it is reasonable to pursue phage therapy for difficult-to-treat infections on a compassionate use basis, but RCT data are critically needed to better inform management.

Glutathione improves low temperature stress tolerance in pusa sheetal cultivar of Solanum lycopersicum

To investigate the impact of Glutathione (GSH) in mitigating low-temperature stress in Pusa Sheetal cv. of Solanum lycopersicum and imparting low-temperature tolerance by evaluating the different physiological responses. The plant under research was also being studied for its growth and stress tolerance. Low temperatures (LT) stress was applied to seedlings with or without GSH application 12 h before LT stress (prophylactic dose), after 12 h-LT (preemptive dose), and post 12-h recovery (curative dose). Different concentrations of GSH [0, G1 (0.5 mM), G2 (1 mM) and G3 (2 mM)] against LT stress were used. Antioxidant activities, photosynthesis, growth, and stress tolerance indices were quantified. LT stress caused an oxidative burst in S. lycopersicum seedlings of the Pusa Sheetal cv. as indicated by increased peroxidation of lipids and H₂O₂ concentration. Glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were enhanced. The best concentration was G2 (1 mM), which resulted in a rise in antioxidant activity. Moreover, a decline in lipid peroxidation and H₂O₂ levels was also seen. The purpose of this study is to identify the role of GSH in reducing LT stress and to find the best dose concentration. This is the first report to assess the GSH-mediated LT stress tolerance in S. lycopersicum (Pusa Sheetal cv.). Therefore, exogenous GSH application of optimal concentration of GSH to LT stressed S. lycopersicum can be an effective approach for augmenting the plant detoxification system and promoting its growth and development.

The effect of induction immunosuppression for kidney transplant on the latent HIV reservoir

The HIV latent viral reservoir (LVR) remains a major challenge in the effort to find a cure for HIV. There is interest in lymphocyte-depleting agents, used in solid organ and bone marrow transplantation to reduce the LVR. This study evaluated the LVR and T cell receptor repertoire in HIV-infected kidney transplant recipients using intact proviral DNA assay and T cell receptor sequencing in patients receiving lymphocyte-depleting or lymphocyte-nondepleting immunosuppression induction therapy. CD4+ T cells and intact and defective provirus frequencies decreased following lymphocyte-depleting induction therapy but rebounded to near baseline levels within 1 year after induction. In contrast, these biomarkers were relatively stable over time in the lymphocyte-nondepleting group. The lymphocyte-depleting group had early TCRβ repertoire turnover and newly detected and expanded clones compared with the lymphocyte-nondepleting group. No differences were observed in TCRβ clonality and repertoire richness between groups. These findings suggest that, even with significant decreases in the overall size of the circulating LVR, the reservoir can be reconstituted in a relatively short period of time. These results, while from a relatively unique population, suggest that curative strategies aimed at depleting the HIV LVR will need to achieve specific and durable levels of HIV-infected T cell depletion.

A Pilot Trial for Prevention of Hepatitis C Virus Transmission From Donor to Organ Transplant Recipient With Short-Course Glecaprevir/Pibrentasvir

A 7-day course of glecaprevir/pibrentasvir started in the preoperative period prevented transmission of hepatitis C virus (HCV) from viremic donors to 10 HCV-negative recipients (2 heart, 1 lung, 6 kidney, 1 heart/kidney) with 100% sustained virological response at 12 weeks.

National Landscape of Human Immunodeficiency Virus-Positive Deceased Organ Donors in the United States

BACKGROUND

Organ transplantation from donors with human immunodeficiency virus (HIV) to recipients with HIV (HIV D+/R+) presents risks of donor-derived infections. Understanding clinical, immunologic, and virologic characteristics of HIV-positive donors is critical for safety.

METHODS

We performed a prospective study of donors with HIV-positive and HIV false-positive (FP) test results within the HIV Organ Policy Equity (HOPE) Act in Action studies of HIV D+/R+ transplantation (ClinicalTrials.gov NCT02602262, NCT03500315, and NCT03734393). We compared clinical characteristics in HIV-positive versus FP donors. We measured CD4 T cells, HIV viral load (VL), drug resistance mutations (DRMs), coreceptor tropism, and serum antiretroviral therapy (ART) detection, using mass spectrometry in HIV-positive donors.

RESULTS

Between March 2016 and March 2020, 92 donors (58 HIV positive, 34 FP), representing 98.9% of all US HOPE donors during this period, donated 177 organs (131 kidneys and 46 livers). Each year the number of donors increased. The prevalence of hepatitis B (16% vs 0%), syphilis (16% vs 0%), and cytomegalovirus (CMV; 91% vs 58%) was higher in HIV-positive versus FP donors; the prevalences of hepatitis C viremia were similar (2% vs 6%). Most HIV-positive donors (71%) had a known HIV diagnosis, of whom 90% were prescribed ART and 68% had a VL <400 copies/mL. The median CD4 T-cell count (interquartile range) was 194/µL (77-331/µL), and the median CD4 T-cell percentage was 27.0% (16.8%-36.1%). Major HIV DRMs were detected in 42%, including nonnucleoside reverse-transcriptase inhibitors (33%), integrase strand transfer inhibitors (4%), and multiclass (13%). Serum ART was detected in 46% and matched ART by history.

CONCLUSION

The use of HIV-positive donor organs is increasing. HIV DRMs are common, yet resistance that would compromise integrase strand transfer inhibitor-based regimens is rare, which is reassuring regarding safety.

Comparative evaluation of different techniques for herniorrhaphy in calves

Umbilical hernia is one of the most common problems in young calves. This problem occurs in dairy sector as well as in the local farmers. Present study was conducted to compare outcomes of four different techniques of herniorrhaphy. Twenty four young calves (n=24) were divided in 4 groups (A, B, C, and D) which underwent four different surgical techniques. Group A underwent vicryl plus suture material and pants-over-west technique, Group B underwent mesh application with Dexon suture material by using simple interrupted suture pattern, Group C underwent closed method with Nylon No. 3 suture material by using vertical mattress suture pattern and Group D underwent clamp application method with Silk No. 2 suture material by using simple interrupted suture pattern. The result showed that mesh application method was comparatively better with respect to feed intake, body weight gain and healing time. There was no reoccurrence with non-significant hematological changes (p≤0.05). It is concluded that mesh application method is safer than other three techniques and there are no systemic effects of this surgical intervention on calves' health.

Fungal conversion of chicken-feather waste into biofortified compost

Poultry industry is amongst highly developed industries of Pakistan, fulfilling the protein demand of rapidly increasing population. On the other hand, the untreated poultry waste is causing several health and environmental problems. The current study was designed to check the potential of keratinolytic fungal species for the conversion of chicken-feather waste into biofortified compost. For the purpose, three fungal species were isolated from soil samples. These strains were pure cultured and then characterized phenotypically and genotypically. BLAST searches of 18S rDNA nucleotide sequence of the fungal isolates revealed that the two fungal isolates belonged to genus Aspergillus and one belonged to genus Chrysosporium. Optimum temperature for Aspergillus flavus, Aspergillus niger and Chrysosporium queenslandicum was 29, 26 and 25 oC, respectively. A. flavus showed maximum (53%) feather degradation, A. niger degraded feather waste up to 37%, while C. queenslandicum showed 21% keratinolytic activity on chicken feathers at their respective temperature optima. The degradation potential of these fungal species showed their ability to form compost that has agro-industrial importance.

Breakthrough Infections and Low Mortality Observed in Heart Transplant Recipients Infected with COVID-19 at UC San Diego

Purpose

Methods

Results

Conclusion

Immunologic Monitoring of a Breakthrough Infection in a Heart and Kidney Transplant Recipient

Introduction

Solid organ transplant recipients (SOTR) have lower SARS-CoV-2 spike seroconversion than healthy subjects (HS) following vaccination. A breakthrough (BT) infection is defined as the detection of SARS-CoV-2 in a respiratory specimen after a person is ≥14 days after completing the recommended doses for a vaccine. We report a case of SARS-CoV-2 BT infection in a SOTR who was immunologically followed longitudinally following vaccination.

Case Report

A 44-year-old man with a history of non-ischemic cardiomyopathy (NICM) and end stage renal disease had undergone heart and kidney transplantation in December 2017 with thymoglobulin induction. His NICM was secondary to radiation for non-Hodgkin's lymphoma treated with autologous bone marrow transplant in 2001. Maintenance immunosuppression consisted of sirolimus 2mg daily, tacrolimus 2mg twice daily (BID), and prednisone 5mg daily at his 1^st Moderna vaccine in April 2021. In anticipation of surgery, sirolimus was stopped and mycophenolate mofetil (MMF) 500mg BID was started. He was on this regimen at the time of his 2^nd Moderna vaccine. Sirolimus was restarted in July and increased to 1mg daily while continuing MMF 500mg BID, tacrolimus, and prednisone. At the end of July, the patient was exposed to several family members with COVID-19. He tested positive 89 days after his 2^nd Moderna vaccine (cycle threshold of 33.5). He was asymptomatic at the time, but later developed fever, myalgias, headache, and loss of taste and smell and was treated with casirivimab and imdevimab monoclonal antibody (mAb) infusion. We assessed the patient's immunologic response 14 days post 2^nd Moderna vaccination and at BT infection prior to mAb infusion and compared this to HS. The patient developed SARS-CoV-2 spike-specific CD4⁺ T cells at 14 days post 2^nd mRNA vaccine at a frequency below the average frequency for HS. At BT infection, the patient did not have SARS-CoV-2 spike-specific CD4⁺ T cells, partly due to virus induced lymphopenia. The patient did not develop spike-specific CD8⁺ T cells, spike IgG or neutralizing antibodies at 14 days post 2^nd Moderna vaccination or at BT infection.

Summary

The patient developed SARS-CoV-2-specific CD4⁺ T cells following vaccination. His uneventful recovery may be secondary to these SARS-CoV-2 specific CD4⁺ T cells post vaccination as well as receiving mAb therapy 8 days post infection.

Long COVID-19 in Heart Transplant Recipients

Purpose

The goal of this study was to assess the frequency and common symptoms of post-acute COVID-19 syndrome (Long COVID-19) in heart transplant recipients (HTR).

Methods

After obtaining IRB approval, we conducted telephone surveys of HTR (n=30) who had tested positive for SARS-CoV-2 to evaluate their experience with acute COVID-19 illness and assess symptoms of Long COVID-19. Symptoms at onset and also beyond 6, 12, and 24 weeks of the initial diagnosis were recorded. Additionally, medical charts were reviewed for detailed information regarding transplant history, immunosuppression, COVID-19 management and hospitalization, and COVID-19 vaccination status.

Results

As noted in Table 1, among the 30 participants, 10 (33%) had symptoms consistent with Long COVID-19. Those with Long COVID-19 were more symptomatic during acute illness, with 40% of patients reporting cough, fevers or chills, and headaches, compared with 15%, 25%, and 20% respectively in those without Long COVID-19. Emergency department visits at initial illness (80% vs. 20%) and admission to the intensive care unit were more frequent (60% vs. 5%) in the Long COVID-19. Symptoms of Long COVID-19 lasted for a median of 9 weeks with 30% reporting ongoing symptoms at week 24. The most common persistent symptoms were depression, confusion, and difficulty concentrating.

Conclusion

This study is an early investigation of a complex syndrome of Long COVID-19 in transplant patients. Long COVID-19 is not well described in the transplant setting. HTR at our center with Long COVID-19 were sicker at their initial COVID-19 diagnosis and had more emergency room visits, hospital admissions, and longer hospital stays than those without subsequent Long COVID-19. Although, recall bias could affect participants’ ability to remember details and symptoms, this would have impacted both groups similarly as the time since COVID-19 diagnosis to study enrollment was similar between the two groups. These are preliminary findings and the study is currently ongoing.

Donor-derived tuberculosis among solid organ transplant recipients in the United States - 2008-2018

Mycobacterium tuberculosis can be transmitted via organ donation and result in severe outcomes. To better understand donor-derived tuberculosis (DDTB), all potential transmissions reported to the Organ Procurement and Transplantation Network (OPTN) Ad Hoc Disease Transmission Advisory Committee between 2008-2018 were analyzed. Among 51 total reports, nine (17%) (9 donors/35 recipients) had ≥1 recipient with proven/probable disease transmission. Of these, eight were reported due to recipient disease, and one was reported due to a positive donor result. Proven/probable DDTB transmissions were reported in six lung and five non-lung recipients. The median time to diagnosis was 104 days post-transplant (range 0-165 days). Pulmonary TB, extrapulmonary TB, pulmonary plus extrapulmonary TB, and asymptomatic TB infection with positive interferon-gamma release assay were present in five, three, one, and two recipients, respectively. All recipients received treatment and survived except for one whose death was not attributed to TB. All donors associated with proven/probable DDTB had ≥1 TB risk factor. Six were born in a TB-endemic country, five had traveled to a TB-endemic country, 3 had been incarcerated, and 3 had latent TB infection. These cases highlight the importance of evaluating donors for TB based on risk factors. Early post-transplant TB in organ recipients of donors with TB risk factors requires prompt reporting to OPTN to identify other potential affected recipients and implement timely treatment interventions. This article is protected by copyright. All rights reserved.

COVID-19 vaccination is protective of clinical disease in solid organ transplant recipients

BACKGROUND

Clinical effectiveness of coronavirus disease 2019 (COVID-19) vaccination in solid organ transplant recipients (SOTR) is not well documented despite multiple studies demonstrating sub-optimal immunogenicity.

METHODS

We reviewed medical records of eligible SOTRs at a single center to assess vaccination status and identify cases of symptomatic COVID-19 from 1/1/2021-8/12/2021. We developed a Cox proportional hazards model using date of vaccination and time since transplantation as a time varying covariate with age and gender as potential time-invariant confounders. Survival curves were created using the parameters estimated from the Cox model.

RESULTS

Among 1904 SOTRs, 1362 were fully vaccinated (96% received mRNA vaccines) and 542 were either unvaccinated (n = 470) or partially vaccinated (n = 72). There were 115 cases of COVID-19, of which 12 occurred in fully vaccinated individuals. Cox regression with date of vaccination and time since transplantation as the time-varying co-variates showed that after baseline adjustment for age and sex, being fully vaccinated had a significantly lower hazard for COVID-19, hazard ratio = 0.29, 95% confidence interval (0.09, 0.91).

CONCLUSION

We found that 2-dose mRNA COVID-19 vaccination was protective of symptomatic COVID-19 in vaccinated vs. unvaccinated SOTRs.

TWEET

COVID-19 vaccination was associated with significantly lower hazard for symptomatic COVID-19 (HR 0.29, 95% CI 0.09, 0.91) among 1904 SOT recipients at a single center from 1/1/2021-8/12/2021. This article is protected by copyright. All rights reserved.