Infections In Immunocompromised Hosts Research Articles

A Case of Scrub Typhus Meningoencephalitis Complicated by a Rare Pathogen Leclercia adecarboxylata

Leclercia adecarboxylata is Gram-negative bacteria and belongs to the family Enterobacteriaceae, which is motile and is considered as a commensal in normal gut flora. It causes opportunistic infection in immunocompromised hosts but also has been isolated from pus, blood, urine, and sputum of immunocompetent hosts. It is often found to be a part of polymicrobial infection indicating synergistic effect, enhancing its virulence. Rarely, it has been isolated from the cerebrospinal fluid of a child, and its coinfection with scrub typhus has hardly been reported. Because of significant morbidity and mortality associated with nosocomial infections, microbiologists and clinicians should be aware of such unusual pathogens such as L. adecarboxylata. Though most L. adecarboxylata isolates are sensitive to many of the antibiotics, their coexistence with multidrug resistant organisms could result in the transmission of resistance elements.

508 A Case Report of Trichosporon asahii Burn Infection: A Not-So-Fungi

Introduction Trichosporon asahii is a yeast-like basidiomycete that can cause infections in immunocompromised hosts including superficial infections, pneumonia, meningitis, fungemia, and disseminated trichosporonosis. These infections have become more common over the last 30 years in patients with burns or other immunosuppressive conditions. Disseminated T. asahii is intrinsically difficult to treat and carries a mortality rate as high as 70% despite the availability of effective medications.MethodsA 61-year-old male was admitted after falling into a vat of pig manure which was 160 degrees F, resulting in approximately 75% total body surface area injury to his anterior and posterior trunk, and bilateral upper and lower extremities. Throughout his hospital course, he underwent surgical debridement on multiple occasions with placement of homograft, autograft, and spray keratinocytes. The earliest cultures to demonstrate T. asahii growth were obtained on post-burn day (PBD) 23 and growth continued until PBD 32. Quantitative colony counts ranged from 600-365000000 CFU/g from left lower and upper extremities and chest. Cultures were obtained in preparation for cultured epithelial autograft placement which occurred on PBD 36. Susceptibility testing was sent and the minimum inhibitory concentration (MIC) results are reported in Table 1. Clinical and Laboratory Standards Institute (CLSI) guidelines for interpretation of susceptibility are not available for T. asahii, but suggested breakpoints are summarized in Table 1.ResultsOn PBD 23, topical amphotericin B irrigation and voriconazole oral suspension were initiated. A voriconazole level was obtained on PBD 31, which was subtherapeutic, and dosing was subsequently adjusted. In total, the patient received 13 days of topical amphotericin B and 21 days of voriconazole for treatment. Subsequent cultures demonstrated microbiologic cure of T. asahii.ConclusionsThis immunocompromised burn patient was successfully treated for Trichosporon asahii using a combination of topical and systemic antifungal agents.

Geotrichum spp: An overlooked and fatal etiologic agent in immunocompromised patients. A case series from a referral center in Mexico.

Geotrichum spp. causes invasive infection in immunocompromised hosts. We describe a case series of 20 patients from Mexico City. Hematologic malignancy was the most common comorbidity. Clinical presentation was mainly lower respiratory tract infection. Mortality was high despite antifungal therapy.

Editorial introductions.

Editorial introductions.

Pseudomonas mosselli: A Case Series on Its Potential as a Rare Opportunistic Pathogen in Immunocompromised Patients

Background: Pseudomonas mosselli is a Gram negative, rod-shaped, aerobic, non-sporing and motile bacterium co-existing in the soil with plants, protecting them from fungal and bacterial infections by producing diverse molecules and causing rare opportunistic infections in immunocompromised hosts. Most common presentations of respiratory infection caused by this isolate include fever, respiratory distress and purulent cough. Satisfactory antibiotic coverage and early diagnosis mostly leads to complete recovery of the patient.
 Cases: Three cases have been included in our case series of which case 1 had type 2 diabetes mellitus, chronic kidney disease and hypertension and was also diagnosed SARS- CoV-2 positive by RT-PCR (Real time polymerase chain reaction), case 2 had Takosubo cardiomyopathy, an immunological disorder with impending heart failure and case 3 suffered from advanced renal failure due to rapidly progressive glomerulonephritis on weekly dialysis and steroid therapy. Pseudomonas mosselii from the respiratory samples of the patients admitted to a tertiary care centre were identified by the culture characteristics, biochemical reactions and species identification, performed by Matrix assisted laser desorption / ionization- time of flight- mass spectrometry (MALDI-TOF-MS).
 Conclusion: Pseudomonas mosselii causes opportunistic infections in immunocompromised patients. Respiratory infections caused by it are highly drug susceptible and can be easily overcome by administration of appropriate antibiotic treatment followed by antibiotic susceptibility testing.

Determination of In vitro Antimicrobial activity of copper on the clinical isolates of Acinetobacter spp

Background: Acinetobacter spp., emerging pathogens equipped with the competence to establish multitudinous severe infections in immunocompromised hosts, are grievous threats to human health. To tackle the enormous burden of disease caused by Acinetobacter spp., the headlong discovery and the advancement of novel therapies are of the essence at this juncture. The present study attempted to determine the antimicrobial effects of copper on the clinical isolates of Acinetobacter spp. (Iso-03 and Iso-04). Methods: The potential deployment of copper-based antibacterial strategies against Acinetobacter spp. was assessed by exposing the isolates to the increasing concentrations of CuSO4 (from 2.5 to 1.5 mM) in liquid culture (M9 minimal medium) for 6 h and also through the exposure of them on solid metal surfaces (stainless steel and copper coupons) for 75 min, wherein the copper sensitivity and resistance of the clinical isolates of Acinetobacter spp. were determined. Results: There was no interference with the growth of the isolates at the low concentrations, whereas the bacterial growth was affected by the high concentrations of CuSO4 at different levels. During the exposure on the solid metal coupons, no loss of viability of isolates was observed on stainless steel, however, the rapid death of isolates was discernible on copper surface, leading to a dramatic decrease in the number of colony-forming units (CFUs), eventually to the limit of detection (3 CFUs per coupon). Conclusion: This study substantiated that copper possesses antimicrobial properties which can be deployed in novel therapies for the prevention of the infections caused by Acinetobacter spp. and other emerging pathogens. Further studies on the sensitivity and resistance of Acinetobacter spp. to copper at the molecular genetics levels can open the door to better exploitation of this metal for the inhibition of the vigorous growth of drug-resistant Acinetobacter spp.

1303. A Rare Case of Legionella micdadei Lung Abscess in an Immunocompromised Patient

Abstract Background Legionella micdadei is the most common legionella species causing infection after L. pneumophila. It usually causes infection in immunocompromised hosts and leads to nodules with tendency to cavitate. It is difficult to culture which makes diagnosis challenging. We report a case or L. micdadei in an immunocompromised host with cavitary pneumonia. Methods Case Report. An 82 year-old female presented with upper abdominal pain for one day duration. She has history of hypertension, coronary artery disease, hyperlipidemia, heart failure, and hypothyroidism. She was diagnosed with hypersensitivity pneumonia 5 months prior, treated with prednisone (40 mg daily). The pain was not associated with nausea, vomiting or diarrhea. She was found with hypoxia despite she denied shortness of breath, cough, hemoptysis or chest pain. There was no fever, chills, headache, myalgia or upper respiratory symptoms. She was afebrile, tachycardic 134/min and hypoxic to 88% on room air. White cell count was 22x10(3) /mcL (90% neutrophils), hemoglobin was 10.4 g/dL, creatinine was 1.23 mg/dL and lactic acid was 3.6 mmol/L. Chest CT scan showed left lower lobe cavitary lesion with surrounding infiltrates (image 1). Quantiferon gold, serum galagtomannan, B-D-glucan, and vasculitis work-up were negative. Bronchoscopy showed a patent airway. Bronchial smears and cultures were negative for bacteria, fungi and mycobacteria. The patient was treated with ceftriaxone and metronidazole with de-escalation to amoxicillin/clavulanate. Bronchial culture was positive for legionella micdadei after discharge, azithromycin was added. Image 1. Cavitary lesion on thoracic CT Results Our patient was considered immunocompromised given steroid use, predisposing her for L. micdadei infection. L. micdadei is considered an opportunistic infection and was reported in hematologic malignancy population. It can cause an invasive lung disease with lung cavities. It needs special media for growth making it difficult to diagnose especially it is not detected by legionella urine antigen. Conclusion L. micdadei should be considered in the differential diagnosis for cavitary lung lesions in immunocompromised patients. Disclosures All Authors: No reported disclosures

62. Follow-Up Blood Culture Practices for Gram-Negative Bloodstream Infections in Immunocompromised Hosts at a Large Academic Medical Center

BackgroundRoutine follow-up blood cultures (FUBC) are strongly recommended for Staphylococcus aureus and Candida spp. bloodstream infections (BSI), but the role of FUBC in Gram-negative (GN) BSI remains controversial. Factors that may result in persistent GN BSI include critical illness, endovascular infection, lack of source control, multidrug resistant organisms (MDRO), end-stage renal disease, or immunocompromised status. As such, FUBC in patients with any of these factors may be warranted to improve clinical outcomes, but the true balance of benefit versus harm remains unknown. Our objective was to evaluate the role of FUBC in immunocompromised patients with GN BSI.MethodsThis was a retrospective observational cohort of adult, immunocompromised patients treated for confirmed GN BSI between January 2019 and December 2020 at University of Maryland Medical Center. Immunocompromise was defined as active hematologic or solid tumor malignancy at time of BSI diagnosis, history of hematopoietic stem cell transplantation (HSCT) or solid organ transplantation (SOT), or absolute neutrophil count (ANC) < 1000 cells/mm3 at any time 30 days prior to BSI diagnosis. FUBC were defined as blood cultures drawn between 24 hours and 7 days from index blood culture, within the same hospital encounter. Positive FUBC was defined as a FUBC with same pathogenic GN organism identified. Comparison of patient and microbiologic characteristics was made between patients with and without FUBC.ResultsA total of 146 patients with GN BSI were included. Baseline characteristics are reported in Table 1. FUBC were collected in 129 (88.4%) patients. Neutropenia (49.6% vs. 19.4%, P=0.122), presence of central line (69.8% vs. 30.2%, P=0.061), and hospital-acquired origin of BSI (63.6% vs. 36.4%, P=0.395) resulted in increased frequency of FUBC. Patients with FUBC had a significantly longer post-BSI mean (SD) length of stay (17.3 [35.4] vs. 6.5 [6.0] days; P=0.005). Positive FUBC occurred in only 2 cases (1.4%) and both patients had persistent fevers at time of FUBC. Table 1. Baseline Characteristics ConclusionPositive FUBC were uncommon in this immunocompromised cohort with GN BSI, which challenges the need for routine collection of FUBC in this patient population.Disclosures Ciera L. Bernhardi, PharmD, Servier Pharmaceuticals (Advisor or Review Panel member) J. Kristie Johnson, PhD, D(ABMM), GenMark (Speaker’s Bureau) Kimberly C. Claeys, PharmD, GenMark (Speaker’s Bureau)

Human parainfluenza virus evolution during lung infection of immunocompromised individuals promotes viral persistence.

The capacity of respiratory viruses to undergo evolution within the respiratory tract raises the possibility of evolution under the selective pressure of the host environment or drug treatment. Long-term infections in immunocompromised hosts are potential drivers of viral evolution and development of infectious variants. We showed that intrahost evolution in chronic human parainfluenza virus 3 (HPIV3) infection in immunocompromised individuals elicited mutations that favored viral entry and persistence, suggesting that similar processes may operate across enveloped respiratory viruses. We profiled longitudinal HPIV3 infections from 2 immunocompromised individuals that persisted for 278 and 98 days. Mutations accrued in the HPIV3 attachment protein hemagglutinin-neuraminidase (HN), including the first in vivo mutation in HN's receptor binding site responsible for activating the viral fusion process. Fixation of this mutation was associated with exposure to a drug that cleaves host-cell sialic acid moieties. Longitudinal adaptation of HN was associated with features that promote viral entry and persistence in cells, including greater avidity for sialic acid and more active fusion activity in vitro, but not with antibody escape. Long-term infection thus led to mutations promoting viral persistence, suggesting that host-directed therapeutics may support the evolution of viruses that alter their biophysical characteristics to persist in the face of these agents in vivo.

Combination of Clofazimine and Atovaquone as a Potent Therapeutic Regimen for the Radical Cure of Babesia microti Infection in Immunocompromised Hosts.

Human babesiosis caused by Babesia microti can be fatal in immunocompromised patients, and the currently used drugs are often ineffective. A recent study found that clofazimine clears B. microti Munich strain in immunocompromised mice. In the present study, we investigated the efficacies of clofazimine and 2-drug combinations involving clofazimine, atovaquone, and azithromycin against B. microti Peabody mjr strain in immunocompromised mice. Treatment with clofazimine alone, clofazimine plus azithromycin, and atovaquone plus azithromycin was ineffective and failed to eliminate the parasites completely, while a 44-day treatment with clofazimine plus atovaquone was highly effective and resulted in a radical cure.

High overall mortality of Mycobacterium genavense infections and impact of antimycobacterial therapy: Systematic review and individual patient data meta-analysis

IntroductionMycobacterium genavense is a fastidious slow growing mycobacterium (SGM) that causes disseminated infections in immunocompromised hosts. It has been described in HIV-positive individuals and increasingly in patients without HIV. The infections are difficult to treat and the optimal antimycobacterial regimen is still unknown. MethodsAn individual patient data meta-analysis was conducted aiming at including all hitherto published cases of infection with M. genavense. Clinical manifestations, microbiological data, dispositions and immunosuppression were recorded. Antimycobacterial therapies and mortality were analyzed by logistic regression and time-to-event analysis. ResultsWe included 223 patients with infection due to M. genavense published from 1992 to 2021. While the majority was HIV positive (n = 171, 76.7%), 52 patients were non-HIV-patients (23.3%), 36 of whom received immunosuppressive therapy (69%). We could confirm the bacterium's tropism for the gastrointestinal tract with abdominal pain, hepato-/splenomegaly and abdominal lymphadenopathy being major clinical manifestations. More than 90% of patients received antimycobacterial therapy. The regimens consisted mainly of macrolides, rifamycins and ethambutol. Overall mortality was high, but in logistic regression and time-to-event analysis a macrolide containing regimen was associated with better outcomes. ConclusionIn this first individual patient data meta-analysis of infections with M. genavense we confirm its tropism for the gastrointestinal tract. The high overall mortality underlines the clinical relevance of infection with this bacterium for the individual patient. In addition, our data give a hint that a macrolide containing regimen is associated with better survival.

The Epidemiology and Pathogenesis and Treatment of Pseudomonas aeruginosa Infections: An Update.

Pseudomonas aeruginosa is a Gram-negative bacterial pathogen that is a common cause of nosocomial infections, particularly pneumonia, infection in immunocompromised hosts, and in those with structural lung disease such as cystic fibrosis. Epidemiological studies have identified increasing trends of antimicrobial resistance, including multi-drug resistant (MDR) isolates in recent years. P. aeruginosa has several virulence mechanisms that increase its ability to cause severe infections, such as secreted toxins, quorum sensing and biofilm formation. Management of P. aeruginosa infections focuses on prevention when possible, obtaining cultures, and prompt initiation of antimicrobial therapy, occasionally with combination therapy depending on the clinical scenario to ensure activity against P. aeruginosa. Newer anti-pseudomonal antibiotics are available and are increasingly being used in the management of MDR P. aeruginosa.

KIR3DS1 directs NK cell-mediated protection against human adenovirus infections.

Human adenoviruses (HAdVs) are a major cause for disease in children, in particular after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Currently, effective therapies for HAdV infections in immunocompromised hosts are lacking. To decipher immune recognition of HAdV infection and determine new targets for immune-mediated control, we used an HAdV infection 3D organoid system, based on primary human intestinal epithelial cells. HLA-F, the functional ligand for the activating NK cell receptor KIR3DS1, was strongly up-regulated and enabled enhanced killing of HAdV5-infected cells in organoids by KIR3DS1+ NK cells. In contrast, HLA-A and HLA-B were significantly down-regulated in HAdV5-infected organoids in response to adenoviral E3/glycoprotein19K, consistent with evasion from CD8+ T cells. Immunogenetic analyses in a pediatric allo-HSCT cohort showed a reduced risk to develop severe HAdV disease and faster clearance of HAdV viremia in children receiving KIR3DS1+/HLA-Bw4+ donor cells compared with children receiving non–KIR3DS1+/HLA-Bw4+ cells. These findings identify the KIR3DS1/HLA-F axis as a new target for immunotherapeutic strategies against severe HAdV disease.

Virus-specific T cells for adenovirus infection after stem cell transplantation are highly effective and class II HLA restricted

Infection with adenoviruses is a common and significant complication in pediatric patients after allogeneic hematopoietic stem cell transplantation. Treatment options with traditional antivirals are limited by poor efficacy and significant toxicities. T-cell reconstitution is critical for the management of adenoviral infections, but it generally takes place months after transplantation. Ex vivo–generated virus-specific T cells (VSTs) are an alternative approach for viral control and can be rapidly generated from either a stem cell donor or a healthy third-party donor. In the context of a single-center phase 1/2 clinical trial, we treated 30 patients with a total of 43 infusions of VSTs for adenoviremia and/or adenoviral disease. Seven patients received donor-derived VSTs, 21 patients received third-party VSTs, and 2 received VSTs from both donor sources. Clinical responses were observed in 81% of patients, with a complete response in 58%. Epitope prediction and potential epitope identification for common HLA molecules helped elucidate HLA restriction in a subset of patients receiving third-party products. Intracellular interferon-γ expression in T cells in response to single peptides and response to cell lines stably transfected with a single HLA molecule demonstrated HLA-restricted CD4+ T-cell response, and these results correlated with clinical outcomes. Taken together, these data suggest that VSTs are a highly safe and effective therapy for the management of adenoviral infection in immunocompromised hosts. The trials were registered at www.clinicaltrials.gov as #NCT02048332 and #NCT02532452.

Case report: pulmonary nocardiosis caused by Nocardia exalbida in an immunocompetent patient

BackgroundNocardiosis is known as an opportunistic infection in immunocompromised hosts, but it occasionally has been reported in immunocompetent patient. The Nocardia exalbida is first-reported in 2006 from Japan, and a few cases of have been reported in only immunocompromised host, and the characteristic is still unclear. We herein describe the first case of pulmonary nocardiosis caused by N. exalbida in an immunocompetent patient.Case presentationA77 -year-old Japanese man was admitted to our hospital on November 2, 2018. He was a lifelong non-smoker with no childhood history of respiratory disease. He had a medical history of dyslipidemia. One month before this admission fevers, sputum, mild cough were developed and he was evaluated in a clinic near our hospital. His diagnosis was community acquired pneumonia within his right middle lobe. He was treated with ceftriaxone 1 g/day intravenously for a week, however his symptoms relapsed a few days later. So, the physician retried ceftriaxone for another 3 days, but his symptoms did not improve. He was referred to our hospital. He was treated with sitafloxacin as an outpatient for a week, however his symptoms got worse. The chest CT showed consolidation and atelectasis in his right middle lobe. Low density area was scattered in consolidation, and right pleural effusion was observed.The patient was diagnosed with pulmonary abscess and he was admitted. Administration of piperacillin/tazobactam improved his condition. We switched antibiotics to amoxicillin/clavulanate, and he was discharged. After 2 weeks, he relapsed and was admitted again. After administration of piperacillin/tazobactam for 3 weeks, we perform bronchoscopy and Nocardia species were cultured from samples of the bronchial wash. The isolates were identified as N. exalbida using 16S rRNA gene sequencing. We prescribed Trimethoprim / Sulfamethoxazole (TMP/SMX) for 4 months. Then we switched to minocycline for renal dysfunction caused from TMP-SMX for 1 more month. After 5 months therapy, Consolidation on CT disappeared, and Nocardiosis was cured.Conclusionwe reported the first case of pulmonary nocardiosis caused by N. exalbida in an immunocompetent patient. N. exalbida infection might be associated with a good response to treatment.

Complement receptor 3 mediates Aspergillus fumigatus internalization into alveolar epithelial cells with the increase of intracellular phosphatidic acid by activating FAK

ABSTRACT Complement receptor 3 (CD11b/CD18) is an important receptor that mediates adhesion, phagocytosis and chemotaxis in various immunocytes. The conidia of the medically-important pathogenic fungus, Aspergillus fumigatus can be internalized into alveolar epithelial cells to disseminate its infection in immunocompromised host; however, the role of CR3 in this process is poorly understood. In the present study, we investigated the potential role of CR3 on A. fumigatus internalization into type II alveolar epithelial cells and its effect on host intracellular PA content induced by A. fumigatus. We found that CR3 is expressed in alveolar epithelial cells and that human serum and bronchoalveolar lavage fluid (BALF) could improve A. fumigatus conidial internalization into A549 type II alveolar epithelial cell line and mouse primary alveolar epithelial cells, which were significantly inhibited by the complement C3 quencher and CD11b-blocking antibody. Serum-opsonization of swollen conidia, but not resting conidia led to the increase of cellular phosphatidic acid (PA) in A549 cells during infection. Moreover, both conidial internalization and induced PA production were interfered by CD11b-blocking antibody and dependent on FAK activity, but not Syk in alveolar epithelial cells. Overall, our results revealed that CR3 is a critical modulator of Aspergillus fumigatus internalization into alveolar epithelial cells.

Editorial introductions.

Current Opinion in Infectious Diseases was launched in 1988. It is part of a successful series of review journals whose unique format is designed to provide a systematic and critical assessment of the literature as presented in the many primary journals. The field of infectious diseases is divided into 11 sections that are reviewed once a year. Each section is assigned to a Section Editor, a leading authority in the area, who identifies the most important topics at that time. Here we are pleased to introduce the Section Editors for this issue. SECTION EDITORS Genovefa A. PapanicolaouGenovefa A. PapanicolaouGenovefa A. Papanicolaou is an Infectious Disease physician focusing in patients with hematologic malignancies and hematopoietic cell transplant recipients. She is the Director of Clinical Trials for the Department of Subspecialty Medicine at Memorial Sloan Kettering Cancer Center and Professor at Weill Cornell Medical College at Cornell University in New York, USA. Her research interests include viral infections, biomarkers and precision prevention. She serves in a volunteer capacity as Chair of the Infectious disease special interest group (ID-SIG) of the American Society of Transplantation and Cellular Therapy (ASTCT). Dionysios NeofytosDionysios NeofytosDionysios Neofytos is an Infectious Disease specialist with expertise in infectious disease complications in patients with hematologic malignancies and bone marrow and solid organ transplant recipients. Since the completion of his training in Infectious Diseases at Thomas Jefferson University Hospital in Philadelphia, PA, USA, in 2006 he has joined the Faculty and worked as an attending physician with the Transplant Infectious Disease Services at the Johns Hopkins University in Baltimore, MD, USA, and the Memorial Sloan Kettering Cancer Center in New York, NY, USA. Since 2016, he joined the Division of Infectious Diseases at the University Hospital of Geneva, in Geneva, Switzerland. His research and area of expertise are focusing on the epidemiology, diagnosis and management of viral and invasive fungal infections in immunocompromised hosts. Trish M. PerlTrish M. PerlTrish M. Perl, MD, MSc, is the Jay P Sanford Professor in the Departments of Medicine (Infectious Diseases) and the Chief of the Division of Infectious Diseases at UT Southwestern Medical Center in Dallas TX, USA. She formerly was at Johns Hopkins University School of Medicine, USA, in the Division of Infectious Diseases in the Department of Medicine, in Epidemiology at the Bloomberg School of Public Health and the Senior Epidemiologist for Johns Hopkins Health System. Dr Perl received her Bachelor of Arts and medical degree from the University of North Carolina at Chapel Hill, USA, and a Master of Science degree from McGill University in Montreal, Canada. She completed a residency in internal medicine at McGill University and a fellowship in infectious diseases and clinical epidemiology at the University of Iowa, USA. She was on faculty at the University of Iowa for several years before moving to Hopkins where she was the Hospital Epidemiologist at Johns Hopkins Hospital from 1996 to 2011 and then the Health System Epidemiologist until 2016 when she moved to UTSW. She has extensive practical and research experience in the field of healthcare associated infections and resistant and epidemiologically significant organisms and is recognized globally for her innovation and research in healthcare associated infections, antimicrobial resistance, their transmission and prevention. Because of this she helped manage international outbreaks including SARS, MERS CoV, Ebola and consults with international governments on guideline development and strategies to prevent healthcare associated and respiratory virus infections and antimicrobial resistance. An active researcher, Dr Perl has been funded by the CDC, BARDA and the Veteran's Affairs Administration over the years. She has authored or coauthored over 250 peer-reviewed articles. She actively reviews grants for the NIH.

Paecilomyces Pneumonia Despite Voriconazole Prophylaxis: A Case Report and Literature Review.

Paecilomyces species are a rare cause of fungal pulmonary infections in immunocompromised hosts. Paecilomyces variotii and Paecilomyces lilacinus are the two most common species of clinical significance. Both species differ in their susceptibility to antifungal agents. We present a rare case of a 47-year-old immunocompromised woman who developed Paecilomyces pneumonia despite being on voriconazole prophylaxis. We also present a review of the literature on other reported cases.LEARNING POINTSPaecilomyces species differ in their susceptibility to antifungal agents.Breakthrough invasive mould infections are increasingly being documented in immunocompromised patients on voriconazole prophylaxis.Posaconazole has been shown to be effective against both Paecilomyces species.

Persistent Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Immunocompromised Host Displaying Treatment Induced Viral Evolution.

We report a coronavirus disease 2019 case with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) persisting beyond 333 days in an immunocompromised patient with chronic lymphocytic leukemia, asymptomatically carrying infectious SARS-CoV-2 at day 197 postdiagnosis. In addition, viral sequencing indicates major changes in the spike protein over time, temporally associated with convalescent plasma treatment.

Evaluation of the Vitek 2, Phoenix, and MicroScan for Antimicrobial Susceptibility Testing of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia causes high-mortality infections in immunocompromised hosts with limited therapeutic options. Many U.S. laboratories rely on commercial automated antimicrobial susceptibility tests (cASTs) and use CLSI breakpoints (BPs) for S. maltophilia. However, contemporary data on these systems are lacking. We assessed performance of Vitek 2, MicroScan WalkAway, and Phoenix relative to that of reference broth microdilution for trimethoprim-sulfamethoxazole (SXT), levofloxacin (LEV), minocycline (MIN), and ceftazidime (CAZ) with 109 S. maltophilia bloodstream isolates. Using CLSI breakpoints, categorical agreement (CA) was below 90% on all systems and drugs, with the exception of SXT by MicroScan (98.1%) and Phoenix (98.1%) and MIN by MicroScan (100%) and Phoenix (99.1%). For SXT, Vitek 2 yielded a 77.1% CA. LEV and CAZ CA ranged from 67% to 85%. Very major errors (VME) were >3% for SXT (MicroScan, Phoenix), LEV (MicroScan), and CAZ (all systems). Major errors (ME) were >3% for SXT (Vitek 2), LEV (Phoenix), and CAZ (MicroScan, Phoenix). Minor errors were >10% for CAZ and LEV on all systems. Data were analyzed with EUCAST pharmacokinetic/pharmacodynamic CAZ, LEV, ciprofloxacin (CIP), and tigecycline (TGC) breakpoints when possible. CA was <90% for all. VME were >3% for CAZ (all systems), LEV (MicroScan), and TGC (Vitek 2), and ME were >3% for LEV (MicroScan), CAZ (all systems), ciprofloxacin (Vitek 2 and MicroScan), and TGC (Vitek 2, Phoenix). Minor errors (MI) were >10% for all agents and systems, by EUCAST breakpoints with an intermediate category (LEV, CAZ, CIP). Laboratories should use caution with cASTs for S. maltophilia, as a high rate of errors may be observed.