bluuebunny/crossref_metadata_2025 huggingface dataset:
977. Invasive Mucormycosis in a Tertiary Care Hospital, Western Saudi Arabia: 11-Year Retrospective Chart Review, from 2009 – 2019
Authors: Almarhabi Hassan , Alasmari Esam , Farahat Faysal , Al-Amri Abdulfattah , Al-Maghraby Hatim , Alharbi Maher , Althaqafi Abulhakeem
Published: December 2021

Background

Mucormycosis is a rare, life-threatening invasive fungal disease that mostly affects immunocompromised hosts. the objectives of this study to assess clinical presentations and outcomes among patients with mucormycosis in a tertiary care hospital, western Saudi Arabia.

Methods

A retrospective chart review of cases diagnosed with mucormycosis was conducted from January 2009 to December 2019 in King Abdulaziz Medical City, Jeddah, in the western region of Saudi Arabia. Data were obtained on demographic information, comorbidities including immunocompromised conditions

Results

16 cases were identified as proven or probable mucormycosis according to revised European organization for research and treatment of cancer/mycoses study group criteria (EORTC/MSGERC). Most cases (n=11, 68.75%) were categorized as proven while 5 cases (31.25 %) as probable. The median age of cases 29.5 years, with 5 cases were less than 18 years. Cutaneous mucormycosis is the predominant presentation as noted in 7 cases (43.75%), followed by rhino-orbital-cerebral mucormycosis in 4 cases (25%), and pulmonary mucormycosis in 2 cases (12.5). Rhizopus and mucor species were the two main fungal isolates. The most common underlying etiology were hematological malignancies (n=7, 43.75%) , trauma with a motor vehicle accident( n=4 ,25%) , and diabetes mellitus(n=4 ,25%) . Most of the patients treated with amphotericin B lipid complex alone or in combination with posaconazole. The average days of antifungal use were 57.2 days. Most patients (n=11, 68.75%) undergone either one or repeated surgical debridement. Overall, 11 (68.75%) patients died, 2 of them prior to a confirmed diagnosis. All pulmonary cases died, the majority (75%) of rhino-orbital-cerebral, and 57.1% of the cutaneous cases died as well.

Conclusion

Mortality among cases with mucormycosis was high. Relatively better survival was observed among the cutaneous cases. A combination of new diagnostic technologies, optimized use of available antifungal options, development of new antifungal agents, and consistent implementation of public health policies may help to reduce mortality rates from mucormycosis in Saudi Arabia.

Disclosures

All Authors: No reported disclosures
980. Universal Lifelong Fungal Prophylaxis and Risk of Coccidioidomycosis in Lung Transplant Recipients Living in an Endemic Area
Authors: Truong Clover N , Nailor Michael D , Walia Rajat , Cherrier Lauren , Nasar Aasya , Goodlet Kellie J
Published: December 2021

Background

Previous studies suggested that 6-12 months of universal or targeted azole prophylaxis is effective in preventing coccidioidomycosis for various organ transplant recipients. However, limited reports have described outcomes with longer prophylactic durations or using mold-active azoles in lung transplant recipients. Therefore, the purpose of this study was to investigate the incidence of coccidioidomycosis and tolerability of universal lifelong azole therapy in this high-risk patient population.

Methods

This study was an IRB-approved, retrospective cohort study of lung transplant recipients transplanted from January 2013 through December 2018. Adult recipients who were initiated on azole antifungal prophylaxis were eligible for inclusion. Recipients who died or received pre-emptive or definitive treatment for coccidioidomycosis during the transplant admission, or who received a previous transplant were excluded from the study. Outcomes were assessed through December 2019 or until the time of coccidioidomycosis diagnosis, death, second transplant, or date lost to follow-up.

Results

Of 544 lung transplants completed between 2013-2018, 493 patients were included with a mean age at transplant of 62 ± 11; 57.3% were male, 88.6% were white, and 77.1% developed post-transplant diabetes. The majority of patients ( > 70%) lived in Arizona or California pre-transplant and at 1-year post-transplant, and most patients had primary transplant indication of COPD and/or pulmonary fibrosis (~75%). One proven coccidioidomycosis infection and one new asymptomatic seropositivity for Coccidioides (incidence 0.2% each) occurred during the study period with median follow-up duration of 31 months. Azole therapy changes were common but permanent discontinuation was rare (1.4%) with reasons for azole switch varying among the different agents as summarized in Table 1.

Table 1. Comparison of azole antifungal exposures and reasons for discontinuation

Conclusion

Lifelong azole antifungal prophylaxis was well-tolerated and effectively protected lung transplant recipients at an Arizona transplant center against coccidioidomycosis. Thus, in the absence of documented intolerance or contraindication, universal lifelong azole antifungal prophylaxis should be considered for all lung transplant recipients residing in a coccidioidomycosis-endemic area.

Disclosures

Michael D. Nailor, PharmD, BCPS (AQ-ID), AbbVie (Consultant)Merck (Consultant)Shionogi (Consultant) Rajat Walia, MD, Astellas (Consultant, Speaker)
981. An Investigation into Possible Nosocomial Clusters and On-Treatment Resistance Patterns in Candidemia
Authors: Erayil Serin Edwin , Todd Robert , Kline Susan E , Selmecki Anna
Published: December 2021

Background

Candidemia has significant clinical implications, due to high rates of mortality and increasing resistance to antifungal drugs. Candida auris shows person-to-person transmission and survival on fomites. We aimed to determine if similar hospital transmission of Candida species, other than C. auris, is occurring. We analyzed candidemia infections for species, geographical, and temporal clusters, and clonality. We also aimed to study resistance patterns in individual patients on antifungal treatment. Here we present our current data from December 2019 – March 2021.

Methods

Patients with candidemia were identified with the help of the clinical microbiology lab serving an urban health system. Isolates were stored prospectively as glycerol stocks at -80 C. Data were collected by retrospective chart review and described in terms of frequency distributions and percentages. Patient locations within the hospital setting were traced by Infection Prevention. A cluster was defined as the same species being isolated from ≥ 2 patients in the same unit within a 90-day period. Genomic DNA was isolated and whole genome sequencing was performed. Genomic data were visualized using the Yeast Mapping Analysis Pipeline. The Minimum Inhibitory Concentration (MIC) was determined using broth microdilution.

Results

105 patients were identified from six hospitals (Table 1). Seven clusters of candidemia were identified (Table 2). Genome sequencing supported that all isolates from an individual patient were genetically related. No clonality was observed for isolates from different patients, including those representing two of the seven clusters (Figure 1). Loss of heterozygosity was detected in isolates collected 15 minutes apart in the same patient, indicating distinct populations. MICs remained the same at 0.5 ug/ml over 6 days in Patients l and m (Table 1). For Patient n, MICs remained at 0.5-1 ug/ml Day 1-8, but increased to 4 ug/ml on Day 9. No copy number variation was observed in these isolates.

Table 1. Species and resistance patterns of candidemia

Table 2. Clusters of candidemia

Figure 1. Yeast Mapping Analysis Pipeline for Clusters 3 and 4 – Candida albicans

Conclusion

We have not found evidence of hospital transmission of candida isolates in our investigations to date. We plan to evaluate clonality in the remaining 5 clusters. Future single nucleotide polymorphism analysis will determine if acquisition of point mutations is causing the increased MIC in Patient n.

Disclosures

All Authors: No reported disclosures
984. Diagnostic Utility of Bronchoalveolar Lavage Pneumocystis jirovecii DNA Polymerase Chain Reaction Assay in Patients with Hematological Malignancies and Hematopoietic Cell Transplantation
Authors: Nanayakkara Deepa , Tegtmeier Bernard , Ross Justine Abella , Dickter Jana , Puing Alfredo , Ho Stephanie , Taplitz Randy , Dadwal Sanjeet
Published: December 2021

Background

Pneumocystis jirovecii, an ubiquitous fungus, can lead to opportunistic pneumonia (PJP) in patients with hematological malignancies (HM) and hematopoietic cell transplantation (HCT) with mild to severe presentation. Unlike patients with HIV, diagnosis of PJP pneumonia is often challenging in patients with HM/HCT possibly related to lower fungal burden versus atypical presentation. The gold standard for diagnosis of PJP from bronchoalveolar lavage fluid (BALF) is cytology, followed by direct fluorescent antigen (DFA), however, in the context of lower fungal burden, quantitative polymerase chain reaction (PCR) is increasingly used. PCR DNA load cut-off for diagnosis of PJP is not established. The objective of this study is to assess the correlation between three tests (cytology, DFA and PCR) and diagnosis of PJP (colonization, possible, probable or proven infection).

Methods

In this retrospective study at City of Hope, HM/HCT patients with BALF performed to investigate pneumonia who tested positive for any of the 3 tests were included. The study period is from July 2014 to July 2020. All patients had a clinical and radiographic diagnosis of pneumonia.

Results

Eighty-five patients were identified to have at least one positive diagnostic test for PJP. Twenty (23.5%) patients had a PCR with less than 84 copies/mL, and colonization was suspected in these patients. Of the remaining 65 patients, 46 had all 3 tests done. Twenty seven (58.7%) patients only had positive PCR ranging from 106 to 588,000 copies/mL with negative DFA and cytology. Twelve (26.1%) patients had either DFA or cytology positive with a positive PCR, and in 6 patients (13%) all 3 tests were positive. All of these 18 patients had clinical presentation and radiographic findings consistent with PJP. Quantitative or qualitative serum beta-D-glucan (BDG) level was available in 28 patients and 17 had a positive test with a level >80 pg/ml.

Conclusion

PJP PCR is a very sensitive test that can lead to early detection of PJP pneumonia in HM/HCT with lower sensitivity of DFA/cytology unless the fungal burden is high. However, the optimal cut off PCR value associated with disease needs to be clinically validated in our patient population and a concurrent serum BDG level can increase diagnostic yield.

Disclosures

All Authors: No reported disclosures
987. Clinical Epidemiology and Outcomes of Invasive Pulmonary Aspergillosis as a Complication of Respiratory Viral Infection in Hospitalized Patients
Authors: De Los Santos Bertha A , Barnes Brian J , Britt Nicholas
Published: December 2021

Background

Invasive pulmonary aspergillosis (IPA) is increasingly recognized as a complication of severe respiratory viral infections (RVIs), including influenza and COVID-19. However, the incidence and outcomes of IPA following other RVIs is not well-described. We hypothesized that IPA may be an underreported complication of non-influenza RVIs. The objective of this study was to quantify the incidence and associated outcomes of IPA following RVI in hospitalized patients.

Methods

We conducted a single-center retrospective cohort study of adult hospitalized patients with RVI diagnosed by multiplex PCR-based assay at the University of Kansas Hospital (Kansas City, Kansas) from September 2018-October 2019. Patients with a diagnosis of proven or probable IPA prior to RVI and those with hospital admission < 24 h were excluded from analysis. Proven or probable IPA was defined according to EORTC/MSGERC consensus definitions. The primary outcome was 1-year all-cause mortality.

Results

A total of 195 patients met study criteria and were included in the analysis. The most common types of RVI observed were rhinovirus/enterovirus (57.9%, n=113), parainfluenza (13.3%, n=26), influenza (8.2%, n=16), and respiratory syncytial virus (7.7%, n=15). The cumulative incidence of IPA infection within 6 weeks of RVI was 5.6% (n=11). Excluding patients co-infected with multiple respiratory viruses (n=5), IPA was numerically more likely to occur following influenza compared to non-influenza RVI (12.5% [ n=2/16] vs. 4.6% [n=8/174]; odds ratio, 2.96; 95% confidence interval [CI], 0.57-15.3; P=0.176). Overall, one-year all-cause mortality was 20% (n=39/195) in this cohort. Development of IPA as a complication of RVI was associated with a significant decrease in 1-year survival (hazard ratio [HR], 3.04; 95% CI, 1.19-7.78; P=0.021), and this relationship persisted after adjustment for age (HR, 2.77; 95% CI, 1.08-7.10; P=0.034).

Conclusion

In a cohort of hospitalized patients with RVI, 5.6% of patients developed proven or probable IPA. Although IPA was more likely to occur in patients with influenza, this complication was also observed with other types of RVI. Invasive pulmonary aspergillosis may be an underappreciated complication of non-influenza RVI in hospitalized patients and warrants continued study.

Disclosures

All Authors: No reported disclosures
989. Isavuconazonium Sulfate Treatment of Blastomycosis: A Case Series
Authors: Scolarici Michael J , Saddler Christopher , Smith Jeannina , Gauthier Gregory
Published: December 2021

Background

Blastomyces fungi, endemic to the Ohio and Mississippi River Valleys, cause pneumonia and disseminated disease in both immunocompetent and immunocompromised patients. Prolonged antifungal therapy is commonly complicated by hepatic toxicity, QT prolongation, and drug interactions. Isavuconazonium sulfate is dosed once daily, does not prolong the QT interval, and has fewer drug interactions, but there is a paucity of data for its use in blastomycosis.

Methods

This case series of blastomycosis treated with isavuconazonium sulfate at the University of Wisconsin Hospital and Clinics from 2015 to December 2019 focuses on long term outcomes. Inclusion criteria were adults, that received at least one day of isavuconazole. Exclusion criteria was no blastomycosis diagnosis.

Results

Of 14 cases, median age was 53 years, 6/14 were female, 11/14 White, 2/14 Black, 1/14 Hmong, 6/14 had a solid organ transplant (4 renal, 1 heart, 1 bilateral lung), 1/14 on a TNF-alpha inhibitor (infliximab). Most cases, 9/14 had moderate severity illness requiring inpatient care, 2/14 required ICU level care, and 3/14 were outpatient. Most cases, 11/14, were initially treated with Liposomal Amphotericin B (LAMB) for a median duration of 14 days, 9/14 cases received itraconazole, 8/14 voriconazole, 1/14 posaconazole. Isavuconazonium sulfate was started after adverse drug effects with other azoles in 10/14 cases, prolonged QT interval in 3/14, drug interactions in 2/14, subtherapeutic azole levels in 2/14. Isavuconazonium sulfate was well tolerated and used for median duration of 255 (average 68% total treatment course). 3/14 cases had adverse reactions to isavuconazonium sulfate: nausea, rash, elevated liver enzymes. There was only one death during therapy from a fatal hemorrhagic stroke, and 2/14 cases were still on therapy at end of data collection. 11/14 were cured after treatment course.

Conclusion

This is the largest case series treating Blastomycosis with isavuconazonium sulfate, and it adds to the evidence that isavuconazonium sulfate can be safely used to treat pulmonary and disseminated blastomycosis. Prospective data is needed to compare isavuconazonium sulfate to other antifungals for the treatment of Blastomycosis.

Disclosures

All Authors: No reported disclosures
990. Fungal Malignant Otitis Externa: Clinical and Therapeutic Features
Authors: Hammami Fatma , Koubaa Makram , Chakroun Amal , Rekik Khaoula , Marrakchi Chakib , Smaoui Fatma , Jemaa Mounir Ben
Published: December 2021

Background

Fungal malignant otitis externa is a rare, but a serious infection that might lead to death if not promptly diagnosed and treated. We aimed to study the clinical, therapeutic and evolutionary features of fungal malignant otitis externa.

Methods

We conducted a retrospective study including all cases of fungal malignant otitis externa hospitalized in the infectious diseases department between 2003 and 2020.

Results

We included 35 patients with a mean age of 68±11 years. There were 18 males (51.4%). All patients were diabetics, and 7 patients had a previous medical history of otitis externa (20%). The use of topical corticosteroids was noted in 10 cases (28.5%). The revealing symptoms were otalgia (97.1%), otorrhea (82.9%) and cephalalgia (54.3%). Physical examination revealed tenderness to palpation of the mastoid bone in 21 cases (60%) and the temporomandibular joint in 16 cases (45.7%). Facial paralysis was noted in 14.3% of the cases. Otoscopic examination revealed stenosis of the external auditory canal (94.3%), granulation tissue (34.3%) and a polyp (31.4%). Candida species were isolated in 22 cases (62.8%) represented by Candida parapsilosis in 15 cases (42.8%) and Candida albicans in 5 cases (14.2%). Serological tests detecting Candida were positive in 12 cases (34.2%). Aspergillus species were isolated in 13 cases (37.1%) represented mainly by Aspergillus flavus in 7 cases (20%). Positive serology results for Aspergillus were noted in 8 cases (22.8%). A polyp or granulation tissue biopsy, performed in 12 cases (34.2%), revealed non-specific inflammatory reaction (28.5%) and the presence of fungal hyphae and spores (5.7%). After empirical antibiotics treatment, patients received fluconazole in 18 cases (51.4%) and voriconazole in 17 cases (48.6%). The median duration of treatment was 3 [1.5-12] months. Both surgery and hyperbaric oxygen therapy were indicated in one case (2.8%). Complications including the onset of contralateral otitis (14.3%) and endocranial extension (8.6%) were noted. The disease evolution was favorable in 65.7% of the cases. Four patients were dead (11.4%).

Conclusion

Involvement of fungal species in malignant otitis externa should be considered in front of the absence of improvement with antibiotic. Prompt treatment might prevent complications.

Disclosures

All Authors: No reported disclosures
991. Blockade of the PD-1/PD-L1 Immune Checkpoint Pathway Improves Mortality, Infection Severity, and Fungal Clearance in an Immunosuppressed Murine Model of Invasive Pulmonary Mucormycosis
Authors: Wurster Sebastian , Albert Nathaniel D , Kontoyiannis Dimitrios P
Published: December 2021

Background

Emerging experimental evidence suggests that immune checkpoint inhibitors (ICIs) enhance antifungal immunity. In addition, there is anecdotal evidence of potential benefit of adjunct PD-1 pathway blockade in patients with intractable mucormycosis. However, proof-of-concept data in animal models are lacking. Therefore, we compared the efficacy of PD-1 and PD-L1 inhibition in an immunosuppressed murine model of invasive pulmonary mucormycosis (IPM).

Methods

Female 8-9-week-old BALB/c mice were immunosuppressed with cyclophosphamide (150 mg/kg on days -4 and -1, 100 mg/kg on day +3) and cortisone acetate (300 mg/kg on day -1) and infected intranasally with 50,000 Rhizopus arrhizus spores (clinical isolate Ra-749, day 0). On days 0, +2, +4, and +6, mice received intraperitoneal injections of 250 µg/kg PD-1 or PD-L1 blocking antibodies versus (vs.) 250 µg/kg of the corresponding isotype antibodies (all antibodies from Leinco Technologies). Survival was monitored for 7 days post-infection. Infection severity was scored using the murine sepsis score (MSS, 0 = healthy to 3 = moribund). Fungal burden in lung tissue was determined by an 18S quantitative PCR assay on day +7 or upon death. 20 mice per treatment were assessed in 2 independent experiments.

Results

Control mice with IPM receiving either of the unspecific isotype antibodies developed severe infection (median MSS on day 7, 2.5-3.0) and had a high 7-day mortality (50-55%). Compared to the corresponding isotype control, PD-L1 inhibition provided a strong therapeutic benefit, significantly improving morbidity (median MSS = 1.0 vs. 2.5, p = 0.002), 7-day mortality (15% vs. 50%, p = 0.02), and fungal burden (3.6k vs. 27.2k spore equivalents/lung, p < 0.001). In contrast, blockade of-PD-1 modestly yet non-significantly reduced infection severity (median MSS = 2.1 vs. 3.0, p = 0.48), 7-day mortality (35% vs, 55%, p = 0.12), and fungal burden (5.6k vs. 40.7k spore equivalents/lung, p = 0.09) compared to isotype control.

Conclusion

Even without concomitant antifungals, blockade of PD-L1 and to a lesser extent of PD-1 improved mortality, infection severity, and fungal clearance in immunosuppressed mice with IPM. Immune phenotyping studies are in progress to better understand the protective antifungal activity of ICIs in IPM.

Disclosures

Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)
994. Comparison of Lactate, Procalcitonin and a Gene Signature Assay Alone or in Combination to Differentiate Sepsis from Non-infectious Systemic Inflammation in ICU Patients
Authors: Hassan Erkan , Davis Roy , Sampson Dayle , Miller Russell
Published: December 2021

Background

Procalcitonin (PCT) and serum lactate (L) are measures of bacterial infection and tissue hypoxia, respectively, but also used to discern sepsis from infection negative systemic inflammation (INSI). However, improved tools are needed to enhance this differentiation. A previously validated gene signature assay (SeptiCyte RAPID) and its correlated score (SeptiScore (SS)) has been reported to effectively differentiate sepsis from INSI.

Objective

To compare early L, PCT and SS results (alone or in combination) in differentiating sepsis from INSI in adult intensive care unit (ICU) patients (Pt).

Methods

Data from a previously reported, prospective study (8 sites). Inclusion criteria: (i) ICU admission with ≥ 2 signs of systemic inflammatory response syndrome; (ii) Therapeutic antibiotic administration; (iii) external 3-physician clinical review classifying each Pt as sepsis or INSI with ≥ 2 reviewer agreement; (iv) L, PCT & SS values within 24 hrs of ICU admission; (v) Statistical Analysis; (iv) Area under the receiving operator curve (AUROC), 95% confidence intervals (CI) via generalized linear models for: (i) Each parameter alone (L, PCT, SS); (ii) Combinations (L + PCT, L + SS, PCT + SS, All 3); (iii) AUROC discriminated Sepsis from INSI model: (a) < 0.7 Sub-Optimal; (b) 0.7-0.8 Good; (c) > 0.8 Excellent. Comparisons conducted via paired t-test.

Results

222 pts, sepsis=113; INSI=109 Similar demographics between groups (NS). Mean age (SD) = 57.9 (17.1) yrs; 58.1% male). Overall mechanically ventilated 60.8% and hospital mortality 17.1%. AUCROC (95% CI) in Table and Figure; AUCROC of L, PCT or SS alone or in combination

L, PCT, SS Comparison of Sepsis vs INSI

Conclusion

L is sub-optimal in discriminating sepsis from INSI. PCT with or without L was acceptable but not as robust as SS. SS alone or in any combination provided superior and significant discrimination between sepsis and INSI. Incorporation of SS into the clinical assessment process for suspected sepsis pts should be evaluated to determine the impact on early detection and Pt management.

Disclosures

Erkan Hassan, Pharm.D., FCCM, Immunexpress (Consultant) Roy Davis, M.D>, Immunexpress (Consultant)Immunexpress (Consultant, Shareholder) Dayle Sampson, Ph.D., Immunexpress (Employee, Shareholder)
995. A Murine Model of Klebsiella pneumoniae Gastrointestinal Colonization with Parenteral Vancomycin Administration
Authors: Cheung Bettina , Lebrun-Corbin Marine , Hauser Alan R
Published: December 2021

Background

As a leading cause of nosocomial infections, Klebsiella pneumoniae poses a significant threat due to its propensity to acquire resistance to many classes of antibiotics, including carbapenems. Gastrointestinal (GI) colonization by K. pneumoniae is a risk factor for subsequent infection as well as transmission to other patients. To study this crucial step in pathogenesis, we developed a mouse model of K. pneumoniae GI colonization using a clinically relevant parenteral antibiotic regimen.

Methods

To improve the clinical relevance of our model, we elected to use intraperitoneal injections of vancomycin, one of the most highly utilized antibiotics in the United States.

Results

To optimize dosage in C57bl/6 mice, we injected 20mg/kg, 350mg/kg, or vehicle (PBS) for three days prior to gastric gavage with 108 colony forming units (CFU) of a low-resistance strain of K. pneumoniae. The mice who received 350mg/kg (a mouse equivalent of a human dose of 1g/day calculated through the FDA guidelines for estimating safe dosing) shed about 107 CFU/g of feces at Day 7 while those receiving the lower dose or vehicle shed 104 CFU/g. Next, we compared 3- or 5-day pre-treatments with vancomycin prior to inoculation with an ST258 (epidemic carbapenem-resistant) strain. At Day 7 post-inoculation, mice who received 5 days shed 1010 CFU/g feces while those who received vancomycin for 3 days or vehicle for 5 days (PBS) shed 106 or 104 CFU/g feces respectively. Thus, we chose 5 days of 350mg/kg vancomycin injection as our regimen for inducing robust GI colonization in mice. Finally, we tested the durability of colonization by following fecal shedding in mice up to Day 60 post-inoculation with a second ST258 strain. Shedding during the first 7 days occurs at about 1010 CFU/g feces, and from day 14 to day 60 fecal loads are stable around 107 CFU/g feces. Results are comparable between male and female mice.

Conclusion

In conclusion, we have developed a mouse model of robust, prolonged GI colonization with multiple strains of K. pneumoniae using controlled dosing of a clinically relevant antibiotic. This model may be used to study a key step in K. pneumoniae pathogenesis and infection prevention in the future.

Disclosures

All Authors: No reported disclosures
119. A Humanized Antibody Targeting the CotH Invasins is Protective Against Murine Mucormycosis
Authors: Gu Yiyou , Alqarihi Abdullah , Singh Shakti , Gebremariam Teclegiorgis , Alkhazraji Sondus , Youssef Eman , Andes David , Ibrahim Ashraf S
Published: December 2021

Background

Despite antifungal therapy and surgical debridement, overall mortality of invasive mucormycosis is >40%. Currently the world is witnessing an explosion in mucormycosis in India among COVID-19 patients with an official count of 28,252 cases as of 06/07/2021. Thus, novel therapeutic modalities are needed. We previously reported on a mouse monoclonal antibody (C2) targeting CotH invasins being protective against mucormycosis. Here, we humanized C2 MAb and assessed its efficacy in vitro and in vivo.

Methods

The C2 (IgG1) paratopes of the heavy chain and light chain were grafted on the most suitable human IgG1 with back mutations in the paratopes needed to restore binding of humanized clones to CotH3 (by biolayer interferometry using Gator). Clones were compared to C2 in their ability to prevent Rhizopus delemar-induced injury to A549 alveolar epithelial and primary human endothelial cells and for enhancing human neutrophil killing of the fungus in vitro. C2 and the humanized clones were also compared for their ability to protect neutropenic mice from mucormycosis induced by R. delemar or Mucor cicrinelloides with and without antifungal therapy.

Results

Three humanized clones showed 10-fold enhanced binding affinity to CotH3 protein (~5 nM for humanized vs. ~50 nM for C2). One humanized clone (VX01) doubled the ability of neutrophils to kill R. delemar and resulted in ~50% reduction in host cell damage. A single low dose of VX01 (30 µg) given 24 h post infection resulted in comparable survival of 60-70% in mice infected intratracheally with either R. delemar or M. cicrinelloides vs. placebo mice (0% survival, P < 0.02). Importantly, VX01 acted synergistically in protecting mice when combined with liposomal amphotericin B or posaconazole in a severe model of mucormycosis with treatment starting 48 h post infection (~70% survival for combination vs. 0-20% survival for monotherapy and reduced lung fungal burden by 1.5 log, P< 0.001). GLP-tissue cross reactivity studies of VX01 showed favorable safety profiles.

Conclusion

VX01 shows enhanced binding to CotH3 protein and maintained the protective features of C2 MAb against murine mucormycosis. Clinical testing of combination therapy of VX01 + antifungals is warranted. VX01 is currently in manufacturing.

Disclosures

Yiyou Gu, PhD, Vitalex Biosciences (Shareholder) Ashraf S. Ibrahim, PhD, Vitalex Biosciences (Shareholder)
996. CD4+ T-Cell Lymphopenia Associated with Frequent Plateletpheresis in Healthy Donors
Authors: Cunningham Phoebe H , Mitre Xhoi , Pierre Djenane , Montesano Christina , Woods Tenaizus , Oganezova Karina , Krauss Jonathan H , Von Salena S , Kupelian John A , Gothing Jon A , Jane Kleinjan , Caldara Lise Ann , Sherman Amy C , Walsh Stephen R , Kaufman Richard M , Baden Lindsey R , Desjardins Michaël
Published: December 2021

Background

Frequent plateletpheresis using the Time Accel leukoreduction system chamber may result in lymphopenia in healthy donors, with increased donation in the previous year associated with CD4+ T-cell count of less than 200 cells/µL. However, this finding has not been replicated and the clinical significance of plateletpheresis-associated lymphopenia remains unclear.

Methods

A prospective observational study of healthy plateletpheresis donors aged 18 or older who donated at least once in the previous 365 days was conducted at the Kraft Blood Center at Brigham and Women’s Hospital/Dana Farber Cancer Institute, where the Time Accel system is used exclusively. Blood was drawn immediately before plateletpheresis or at least 2 weeks after the last donation to assess for total lymphocyte and CD4+ T-cell counts.

Results

A total of 86 participants were enrolled: 23 had 1-5 donations, 36 had 6-19 donations, and 27 had 20-24 donations within the previous 365 days (Figure 1). For the low-, medium-, and high-frequency donation groups, the median age was 53 years (IQR 43-64), 61 years (IQR 53-68), and 61 years (IQR 55-65), respectively. The median total lymphocyte count was 1.5 (IQR 1.3-1.9), 1.2 (IQR 0.9-1.5), 0.8 (IQR 0.6-0.9) 103 cells/µL, and the median CD4+ T-cell count was 648 (IQR 531-843), 525 (IQR 348-698), and 220 (IQR 184-347) cells/µL. CD4+ T-cell counts were < 200 cells/µL in 0/23 (0%), 3/36 (8%), and 9/27 (33%) participants across the three groups. Total lymphocyte and CD4+ T-cell counts were inversely correlated with the number of platelet donations in the prior 365 days, R2 = 0.384 (Fig 2) and 0.402 (Fig 3) respectively.

Conclusion

Frequent plateletpheresis using Time Accel leukoreduction system chamber is associated with CD4+ T-cell lymphopenia, with counts below 200 cells/µL seen in one third of those who donated 20-24 times in the previous year. Vaccine immunogenicity studies are ongoing to evaluate the clinical significance of this finding.

Disclosures

Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator)
1000. Serotype 3 pneumococci evade activation of the classical complement pathway
Authors: Lapidot Rotem , Ramirez Mario , Lee Dayeun , Scully Ingrid L , Gessner Bradford D , pelton stephen
Published: December 2021

Background

Complement classical pathway (CCP) activation is the major mechanism leading to opsonophagocytic pneumococcal killing. Following immunization with 13-valent pneumococcal conjugate vaccine (PCV13), opsonophagocytic titers are lowest against serotype 3 among the 13 vaccine serotypes. Post licensure surveillance indicated early declines in serotype 3 invasive pneumococcal disease (IPD) were not sustained over time

Methods

Using flow cytometry, we measured C3 and C4 deposition on serotype 3 strains from children with IPD or nasopharyngeal [NP] carriage, and analyzed by clade. C4 deposition is an indicator of CCP, while C3 deposition is common to all complement pathways. We measured C3/C4 deposition on serotype 3 pneumococcal strains incubated with antibody depleted complement alone or with complement and the following antibodies: mouse monoclonal anti-capsular IgG or IgM, rabbit polyclonal serotype 3 antisera (IgG + IgM) [RPS3A] and RPS3A combined with anti-rabbit IgM, which blocks IgM function, leaving only polyclonal IgG

Results

Serotype 3 strains demonstrated high variability in C3 binding when incubated with complement alone. RPS3A (containing both IgM+IgG) and monoclonal IgM activated CCP in all strains. Anti- serotype 3 monoclonal IgG and polyclonal IgG demonstrated absent or limited CCP activation; but activated alternative pathway in some strains. When analyzing complement deposition by clade, a lower proportion of clade II NP serotype 3 strains bound C3 when incubated with complement or monoclonal IgG, compared to clade Ia NP strains. Differences between clade Ia and II IPD strains were not apparent.

Conclusion

Serotype 3 strains did not demonstrate activation of the CCP in the presence IgG and varied in C3 deposition. Pneumococcal strains that evade CCP activation may be less sensitive to opsonophagocytosis. Our findings suggest a mechanism by which serotype 3 carriage and disease may persist despite immunization with conjugate vaccine containing serotype 3 polysaccharide.

Disclosures

Rotem Lapidot, MD MSCI, Pfizer (Consultant, Grant/Research Support, Advisor or Review Panel member) Mario Ramirez, PhD, GlaxoSmithKline (Advisor or Review Panel member)Merck Sharp & Dohme (Advisor or Review Panel member)Pfizer (Speaker’s Bureau) Ingrid L. Scully, PhD, Pfizer (Employee, Shareholder) Bradford D. Gessner, MD, MPH, Pfizer Inc. (Employee) stephen pelton, MD, Merck Vaccines (Advisor or Review Panel member, Research Grant or Support)Pfizer, Inc. (Consultant, Advisor or Review Panel member, Research Grant or Support)Sanofi pasteur (Advisor or Review Panel member, Research Grant or Support, DSMB)Seqirus (Consultant)
1003. Cytokine Levels in Sepsis and TNFα Association with Mortality but not Sepsis Severity or Infection Source: a Systematic Review and Meta-analysis
Authors: Gharamti Amal , Samara Omar , Monzon Anthony , Barahona Lilian Vargas , Scherger Sias , DeSanto Kristen , Chastain Daniel B , Sillau Stefan , Franco-Paredes Carlos , Henao Martínez Andrés F , Shapiro Leland
Published: December 2021

Background

Sepsis is a global health problem associated with significant morbidity and mortality and is attributed to a “cytokine storm.”. However, anti-cytokine therapies have failed to lower sepsis mortality in clinical trials. Linking cytokine excess to sepsis pathogenesis requires quantification of cytokine levels in sepsis. This systematic review and meta-analysis characterizes levels of key cytokines in the circulation of sepsis patients and relates TNFα levels to mortality and patient characteristics.

Methods

Medline, Embase, Cochrane Library, and Web of Science Core Collection databases were searched from 1946 to May 2020 for studies in English disclosing cytokine levels in sepsis. Keywords included sepsis, septic shock, purpura fulminans, and tumor necrosis factor (TNF)α. We related cytokine amounts to 28-day mortality. Data analyses were performed using a random-effects model to estimate pooled odds ratios (OR) and 95% confidence intervals (CI). This systematic review is registered in PROSPERO under number CRD42020179800.

Results

A total of 3656 records were identified. After exclusions, 103 studies were included. Among these studies, 72 disclosed TNFα levels, 25 showed interleukin (IL)-1β levels, and 6 presented interferon (IFN)γ levels. The pooled estimate mean TNFα concentration in sepsis patients was 58.4 pg/ml (95% CI, 39.8-85.8 pg.ml; I2 = 99.4%). Pooled estimate means for IL-1α and IFNγ in sepsis patients were 21.8 pg/ml (95% CI, 12.6-37.8 pg.ml; I2 =99.8%) and 63.3 pg/ml (95% CI, 19.4-206.6 pg/ml; I2 = 99.7%), respectively. Elevated TNFα concentrations were associated with increased 28-day mortality (P=0.001). In a subgroup analysis, TNFα levels did not relate to sepsis source, sepsis severity, or sequential organ failure assessment (SOFA) score (figure 1). In a metaregression, TNFα associated with age, percentage of females and mortality at 28 days.

Figure 1: A: TNFa levels according to sepsis source. B: TNFa levels according to measurement technique. C: TNFa levels according to presence or absence of cardiovascular disease. D: TNFa levels according to presence or absence of malignancy. E: TNFa levels according to sepsis severity. F: TNFa levels in fungal compared to other causes of sepsis (Yes=fungal sepsis; No= Other types of sepsis). G: TNFa levels according to SOFA score. H: TNFa levels and mortality at 28 days.

Conclusion

We presented levels of TNFα, IL-1β, and IFNγ in human sepsis and showed that TNFα elevations are associated with sepsis mortality. TNFα concentrations did not correlate with sepsis severity. We believe the concept that elevated cytokines cause sepsis should be revisited in the context of these data.

Disclosures

All Authors: No reported disclosures
1005. COVID-19 At-Home Capillary Blood Specimen Collection Pilot – Gaining Insight into Independent Self- Collection of Blood Specimens and COVID-19 Within the Veteran Population
Authors: Mohammed Tseli , Brewer Jessica V , Pyatt Mary E , Romero Casas Juan P , Whitbourne Stacey , Michael Gaziano J , Edson Connor W , Holodniy Mark
Published: December 2021

Background

The VA Million Veteran Program (MVP) studies what factors influence Veteran health. Current procedures involve collection of venous blood at MVP enrollment sites. To examine home specimen collection options, MVP performed a pilot study comparing two blood specimen collection devices and evaluated SARS-CoV-2 antibody assays to determine known COVID-19 infection or vaccination.

Methods

A sub-sample of MVP Veteran participants were asked to self-collect a capillary blood specimen using the Neoteryx Mitra Clamshell (up to 120uL dried blood) or Tasso-SST (up to 200uL liquid blood) per the vendor instructions. Veterans were randomly assigned to a device prior to consent. Eligibility included 30% of Veterans with known COVID-19 diagnosis or vaccination and sampling time was variable from these events. Veterans rated their device experience and shipped collected specimens directly to an MVP laboratory. Mitra tip (4) blood was eluted in 1 mL of 0.9% normal saline for 1 hour at room temperature shaking at 300 rpm. Tasso tubes were centrifuged per vendor instructions. All samples were stored at -80°C until tested with SARS-Cov-2 antibody (Ab) assays (InBios Spike IgG, BioRad Nucleocapsid (NC) Total Ab, Abbott NC IgG, and Abbott Spike IgG II) per vendor instructions.

Results

312 MVP participants consented to the pilot (52%) of which 136 (43.6%) were sent Mitra and 176 (56.4%) were sent Tasso-SST (Table 1). Participants rated the Mitra Tasso-SST equally on average as 4.4 on a 0-5 usability scale. The Abbott IgG II assay had the highest sensitivity across both devices (87% Mitra and 98% Tasso-SST) for detecting known COVID infection and/or vaccination. The InBios IgG assay with the Tasso-SST had the best sensitivity (97%) and specificity (80%) for detecting known COVID-19 infection and/or vaccination (Table 2).

Table 1. COVID-19 At-Home Capillary Blood Specimen Collection Pilot Outcomes

Conclusion

Veterans successfully collected their own specimens and had no strong preference for either device. The Tasso-SST combined with the InBios Spike IgG assay provided the highest combination of sensitivity and specificity. Limitations included one collection device per subject, varied timing of testing, unknown infection or vaccination status among some, and Tasso collection volume and Mitra whole blood dilution may have affected comparison across assays or performance.

Disclosures

All Authors: No reported disclosures
1007. Hypermutability in Clinical Strains of Klebsiella pneumoniae: Role of the V76G Mutation in MutH
Authors: Cheng Shaoji , Liu Guojun , Hao Binghua , Newbrough Anthony , Clancy Cornelius J , Nguyen Minh-Hong
Published: December 2021

Background

Hypermutator (HM) bacteria exhibit high spontaneous mutation rates due to DNA mismatch repair (MMR) gene mutations, which may facilitate antibiotic resistance. HM is best described for chronic infections or colonization, in particular with P. aeruginosa. HM K. pneumoniae (KP) and carbapenem resistant Enterobacterales (CRE) are rarely studied.

Methods

Longitudinal isolates from 5 patients (pts) with long-term ST258 CRKP infections (median: 1.4 yr, 0.5-4.1 yr) underwent Illumina HiSeq whole genome sequencing. Strains from 1 pt were tested for HM and resistance. Mutant strains were created by complementation and CRISPR.

Results

In each pt, initial and recurrent isolates were genetically related (≤7 core genome (cg) SNP). In 1 pt, infection recurred 3.3 yrs after initial infection; baseline and recurrent (T0) isolates differed by 7-10 cgSNP. 4 ceftazidime-avibactam (CAZ) resistant isolates (T1-T4) were recovered ≥2 wks after treatment of T0 infection. Strains T1-T4 differed from T0 and each other by 109-214 and 58-137 cgSNP (Fig.1), respectively, and carried mutations in MMR genes (mutS -149∆C (∆pmutS); mutH V76G) and blaKPC3 (D179Y). T1-T4 mutations were enriched for genes involved in metabolism (adjusted p=1.46e-10), ABC transport (p=4.1e-7), 2-component systems (p=9.2e-5), signal transduction (p=6e-4), and transcription regulation (p=2.1e-4). mutS and mutH expression was 46-49% lower in T1-T4 than in T0. T1-T4 demonstrated rifampin mutational frequency >10-6.4, compared to < 10-7.3 for earlier strains. Upon passage in meropenem-vaborbactam (MV), colistin and gentamicin, T1-T4 developed resistance faster and higher MICs than T0 (Fig 2). MV resistance was associated with IS5 ompk36 promoter insertions or point, deletion or STOP mutations in ompK36 coding region. Complementation of T1-T4 with wild-type (WT) mutH restored phenotypes. Introduction of V76G to WT mutH in T0 established HM and in vitro passage resistance phenotypes.

SNP matrix of 11 clinical isolates from a single patient with recurrent KPC-Kp infections

The first 6 isolates were recovered within 6 months of transplant (Tinitial). The later 5 isolates were recovered ~40 months after intial GI colonization. Number of SNPs for each pariwise comparision on isolates are shown. Gray highlighted boxes shown SNP defferences between the 5 later strains.

Serial passages of 4 clinical isolates.

T1 and T4 harbored ΔpmutS. Ti=Tinitial (baseline) isolates

Conclusion

MMR mutations emerged in longitudinal CRKP, which conferred HM phenotypes and were associated with CAZ and other anti-CRE antibiotic resistance. mutH V76 is crucial in MMR. Long-term colonization or recurrent infections in face of antibiotic exposure might predispose CRKP strains to HM.

Disclosures

Cornelius J. Clancy, MD, Merck (Grant/Research Support)
1011. Geospatial Analysis of Antibiotic Susceptibility in Wisconsin
Authors: Legenza Laurel , McNair Kyle , Lacy James P , Gao Song , Rose Warren
Published: December 2021

Background

The global threat of antimicrobial resistance (AMR) varies regionally. Regional differences may be related to socio-economic factors such as the Area Deprivation Index (ADI) score. Our hypothesis is that AMR spatial distribution is not random.

Methods

Patient level antibiotic susceptibility data was collected from three regionally distinct Wisconsin health systems (UW Health, Fort HealthCare, Marshfield Clinic Health System [MCHS]). Patient addresses were geocoded to coordinates and joined with US Census Block Groups. For each culture source, we included the initial E. coli isolate per patient per year with a patient address in Wisconsin. Percent susceptibility was calculated by block group. Spatial autocorrelation was determined by Global Moran’s I, which quantifies the attribute being analyzed as spatially dispersed, randomly distributed, or clustered by a range of −1 to +1. Linear regression correlated ADI to susceptibility. Hot spot analysis identified blocks with statistically significant higher and lower susceptibility (Figure 1).

Figure 1. Geographic example of hot spot analysis and interpretation.

Results

The UW Health results included more urban areas, more block groups and greater isolate geographic density (n = 44,629 E. coli, 2009-2018), compared to Fort HealthCare (n = 6,065 isolates, 2012-2018) and MCHS (50,405 isolates, 2009-2018). A positive spatially clustered pattern was identified from the UW Health data for ciprofloxacin (Moran’s I = 0.096, p = 0.005) and trimethoprim/sulfamethoxazole (TMP/SMX) susceptibility (Moran’s I = 0.180, p < 0.001; Figures 2-3). Fort HealthCare and MCHS distribution was likely random for TMP/SMX and ciprofloxacin by Moran’s I. Linear regression of ADI (scale 1-10, least to most disadvantaged) and susceptibility did not find significance, but susceptibility was lower in more disadvantaged block groups. At the local level, we identified hot and cold spots with 90%, 95%, and 99% confidence, with more hot spots in rural regions.

Figure 2. Results from Moran’s Index analysis identifying geographically clustered ciprofloxacin susceptibility results.

Figure 3. Results from Moran’s Index analysis identifying geographically clustered sulfamethoxazole/trimethoprim susceptibility results.

Conclusion

Overall, Moran’s I analysis is more able to identify a clustered pattern in urban versus rural areas. Yet, the local hot spot results indicate that variations in antibiotic susceptibility may be more common in rural areas. The results are limited to data from patients with access to the health systems included.

Disclosures

Warren Rose, PharmD, MPH, Merck (Grant/Research Support)Paratek (Grant/Research Support, Advisor or Review Panel member)
1014. Effect of Levofloxaclin and Trimethoprim-sulfamethoxazole on Planktonic and Biofilm Cells of Stenotrophomonas maltophilia Isolates Obtained from Blood and Respiratory Samples
Authors: Del Río-Chacón José Mauricio , Rojas-Larios Fabian , Villarreal-Salazar Verónica , Ibarías Paola Bocanegra , Newton-Sanchez Oscar Alberto , Camacho-Ortiz Adrian , Flores-Treviño Samantha
Published: December 2021

Background

Stenotrophomonas maltophilia is a non-fermenting Gram-negative pathogen, which causes healthcare-associated infections and exhibits increasing drug resistance rates. In this study, we compared the effect of levofloxacin and trimethoprim-sulfamethoxazole on planktonic and biofilm cells of S. maltophilia isolates obtained from blood and respiratory samples.

Methods

S. maltophilia isolates were recollected from patients older than 18 years from 2018-2020 from Hospital Universitario Dr. Jose Eleuterio Gonzalez, a tertiary care hospital from Nuevo Leon, Mexico. Bacteria were dentified by MALDI-TOF MS. Biofilm formation was determined using the crystal violet staining method.Antimicrobial susceptibility in planktonic cells and biofilm cells were determined by the broth microdilution and the Calgary device, respectively.

Results

During the 3-year study period, 44 S. maltophilia isolates were identified, 28.8% of which were biofilm producers. Of those, 69.2% were obtained from blood cultures. Isolates were obtained from several wards: 25% infectious diseases ward, 18% nephrology, 18% intensive care units, 14% geriatric ward, 7% plastic surgery, and 18% from other wards. The majority of the studied subjects were men (34.6%), and the mean age was 41 years. The majority of the isolates were susceptible to levofloxacin (94.1%) and to trimethoprim-sulfamethoxazole (76.4%) in planktonic assays. All the isolates were resistant to both antibiotics when analyzing biofilm cells. Levofloxacin resistance was at least four-fold higher in biofilm cells compared to planktonic cells. Trimethoprim-sulfamethoxazole resistance was at least ten-fold higher in biofilm cells compared to planktonic cells.

Conclusion

The majority of S. maltophilia clinical isolates causing blood infections in a hospital in Mexico were able to produce biofilm. The production of biofilm in S. maltophilia strains enhanced resistance to levofloxacin and trimethoprim-sulfamethoxazole.

Disclosures

All Authors: No reported disclosures