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Atwood DT, Köhler JR, Vargas SO, Wong W, Klouda T. Identification of Irpex and Rhodotorula on surveillance bronchoscopy in a pediatric lung transplant recipient: A case report and review of literature of these atypical fungal organisms. Pediatr Transplant 2024; 28:e14759. [PMID: 38623871 DOI: 10.1111/petr.14759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 03/14/2024] [Accepted: 04/01/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND Invasive fungal disease (IFD) is a frequent complication in pediatric lung transplant recipients, occurring in up to 12% of patients in the first year. Risk factors for infection include impaired lung defenses and intense immunosuppressive regimens. While most IFD occurs from Aspergillus, other fungal conidia are continuously inhaled, and infections with fungi on a spectrum of human pathogenicity can occur. CASE REPORT We report a case of a 17-year-old lung transplant recipient in whom Irpex lacteus and Rhodotorula species were identified during surveillance bronchoscopy. She was asymptomatic and deemed to be colonized by Irpex lacteus and Rhodotorula species following transplant. 2 years after transplantation, she developed a fever, respiratory symptoms, abnormal lung imaging, and histological evidence of acute and chronic bronchitis on transbronchial biopsy. After developing symptoms concerning for a pulmonary infection and graft dysfunction, she was treated for a presumed IFD. Unfortunately, further diagnostic testing could not be performed at this time given her tenuous clinical status. Despite the initiation of antifungal therapy, her graft function continued to decline resulting in a second lung transplantation. CONCLUSIONS This case raises the concern for IFD in lung transplant recipients from Irpex species. Further investigation is needed to understand the pathogenicity of this organism, reduce the incidence and mortality of IFD in lung transplant recipients, and refine the approach to diagnosis and manage the colonization and isolation of rare, atypical fungal pathogens in immunocompromised hosts.
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Affiliation(s)
- Daniel T Atwood
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Julia R Köhler
- Division of Infectious Disease, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Sara O Vargas
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Wai Wong
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Timothy Klouda
- Division of Pulmonary Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
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2
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Rhee C, Klompas M, Pak TR, Köhler JR. In Support of Universal Admission Testing for SARS-CoV-2 During Significant Community Transmission. Clin Infect Dis 2024; 78:439-444. [PMID: 37463411 DOI: 10.1093/cid/ciad424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/27/2023] [Accepted: 07/13/2023] [Indexed: 07/20/2023] Open
Abstract
Many hospitals have stopped or are considering stopping universal admission testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We discuss reasons why admission testing should still be part of a layered system to prevent hospital-acquired SARS-CoV-2 infections during times of significant community transmission. These include the morbidity of SARS-CoV-2 in vulnerable patients, the predominant contribution of presymptomatic and asymptomatic people to transmission, the high rate of transmission between patients in shared rooms, and data suggesting surveillance testing is associated with fewer nosocomial infections. Preferences of diverse patient populations, particularly the hardest-hit communities, should be surveyed and used to inform prevention measures. Hospitals' ethical responsibility to protect patients from serious infections should predominate over concerns about costs, labor, and inconvenience. We call for more rigorous data on the incidence and morbidity of nosocomial SARS-CoV-2 infections and more research to help determine when to start, stop, and restart universal admission testing and other prevention measures.
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Affiliation(s)
- Chanu Rhee
- Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Healthcare Institute, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Michael Klompas
- Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Healthcare Institute, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Theodore R Pak
- Department of Population Medicine, Harvard Medical School/Harvard Pilgrim Healthcare Institute, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Julia R Köhler
- Division of Infectious Diseases, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
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Acosta-Zaldívar M, Qi W, Mishra A, Roy U, King WR, Patton-Vogt J, Anderson MZ, Köhler JR. Candida albicans' inorganic phosphate transport and evolutionary adaptation to phosphate scarcity. bioRxiv 2024:2024.01.29.577887. [PMID: 38352318 PMCID: PMC10862840 DOI: 10.1101/2024.01.29.577887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Phosphorus is essential in all cells' structural, metabolic and regulatory functions. For fungal cells that import inorganic phosphate (Pi) up a steep concentration gradient, surface Pi transporters are critical capacitators of growth. Fungi must deploy Pi transporters that enable optimal Pi uptake in pH and Pi concentration ranges prevalent in their environments. Single, triple and quadruple mutants were used to characterize the four Pi transporters we identified for the human fungal pathogen Candida albicans, which must adapt to alkaline conditions during invasion of the host bloodstream and deep organs. A high-affinity Pi transporter, Pho84, was most efficient across the widest pH range while another, Pho89, showed high-affinity characteristics only within one pH unit of neutral. Two low-affinity Pi transporters, Pho87 and Fgr2, were active only in acidic conditions. Only Pho84 among the Pi transporters was clearly required in previously identified Pi-related functions including Target of Rapamycin Complex 1 signaling and hyphal growth. We used in vitro evolution and whole genome sequencing as an unbiased forward genetic approach to probe adaptation to prolonged Pi scarcity of two quadruple mutant lineages lacking all 4 Pi transporters. Lineage-specific genomic changes corresponded to divergent success of the two lineages in fitness recovery during Pi limitation. In this process, initial, large-scale genomic alterations like aneuploidies and loss of heterozygosity were eventually lost as populations presumably gained small-scale mutations. Severity of some phenotypes linked to Pi starvation, like cell wall stress hypersensitivity, decreased in parallel to evolving populations' fitness recovery in Pi scarcity, while that of others like membrane stress responses diverged from these fitness phenotypes. C. albicans therefore has diverse options to reconfigure Pi management during prolonged scarcity. Since Pi homeostasis differs substantially between fungi and humans, adaptive processes to Pi deprivation may harbor small-molecule targets that impact fungal growth and virulence.
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Affiliation(s)
- Maikel Acosta-Zaldívar
- Division of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA
- Current affiliation: Planasa, Valladolid, Spain
| | - Wanjun Qi
- Division of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA
| | - Abhishek Mishra
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI
| | - Udita Roy
- Division of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA
| | - William R. King
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Jana Patton-Vogt
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Matthew Z. Anderson
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI
- Department of Medical Genetics, Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI
| | - Julia R. Köhler
- Division of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, MA 02115, USA
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4
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King WR, Acosta-Zaldívar M, Qi W, Cherico N, Cooke L, Köhler JR, Patton-Vogt J. Glycerophosphocholine provision rescues Candida albicans growth and signaling phenotypes associated with phosphate limitation. mSphere 2023; 8:e0023123. [PMID: 37843297 PMCID: PMC10732039 DOI: 10.1128/msphere.00231-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/30/2023] [Indexed: 10/17/2023] Open
Abstract
IMPORTANCE Candida albicans is the most commonly isolated species from patients suffering from invasive fungal disease. C. albicans is most commonly a commensal organism colonizing a variety of niches in the human host. The fungus must compete for resources with the host flora to acquire essential nutrients such as phosphate. Phosphate acquisition and homeostasis have been shown to play a key role in C. albicans virulence, with several genes involved in these processes being required for normal virulence and several being upregulated during infection. In addition to inorganic phosphate (Pi), C. albicans can utilize the lipid-derived metabolite glycerophosphocholine (GPC) as a phosphate source. As GPC is available within the human host, we examined the role of GPC in phosphate homeostasis in C. albicans. We find that GPC can substitute for Pi by many though not all criteria and is likely a relevant physiological phosphate source for C. albicans.
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Affiliation(s)
- William R. King
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Maikel Acosta-Zaldívar
- Department of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Wanjun Qi
- Department of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Nicholas Cherico
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Lauren Cooke
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Julia R. Köhler
- Department of Infectious Diseases, Boston Children’s Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Jana Patton-Vogt
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
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5
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Mahoney West H, Milliren CE, Manne-Goehler J, Davis J, Gallegos J, Perez JH, Köhler JR. Effect of clinician information sessions on diagnostic testing for Chagas disease. PLoS Negl Trop Dis 2022; 16:e0010524. [PMID: 35709253 PMCID: PMC9242495 DOI: 10.1371/journal.pntd.0010524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 06/29/2022] [Accepted: 05/20/2022] [Indexed: 11/23/2022] Open
Abstract
Background Chagas disease is a potentially life-threatening neglected disease of poverty that is endemic in continental Latin America. Caused by Trypanosoma cruzi (T. cruzi), it is one of six parasitic diseases in the United States targeted by the Centers for Disease Control as a public health problem in need of action. An estimated 300,000 people are infected with T. cruzi in the United States (US). Although its morbidity, mortality and economic burden are high, awareness of Chagas disease is lacking among many healthcare providers in the US. The purpose of this analysis is to determine if the number of diagnostic tests performed at a community health center serving an at-risk population for Chagas disease increased after information sessions. A secondary aim was to determine if there was a difference by provider type, i.e., nurse practitioner vs. physician, or by specialty in the number of patients screened. Methodology/Principal findings We conducted a retrospective data analysis of the number of Chagas serology tests performed at a community health center before and after information sessions for clinicians. A time series analysis was conducted focusing on the Adult and Family Medicine Departments at East Boston Neighborhood Health Center (EBNHC). Across all departments there were 1,957 T. cruzi tests performed before the sessions vs. 2,623 after the sessions. Interrupted time series analysis across departments indicated that testing volume was stable over time prior to the sessions (pre-period slope = +4.1 per month; p = 0.12), followed by an immediate shift after the session (+51.6; p = 0.03), while testing volume remained stable over time after the session (post-period slope = -6.0 per month; p = 0.11). Conclusion/Significance In this study, Chagas testing increased after information sessions. Clinicians who began testing their patients for Chagas disease after learning of the importance of this intervention added an extra, potentially time-consuming task to their already busy workdays without external incentives or recognition. Chagas disease is a potentially fatal neglected disease of poverty. It is endemic in continental Latin America with an estimated 300,000 cases in the United States, primarily among low-income people who have immigrated to the US from Latin America. Few Chagas screening programs have been established in the US. Existing recommendations for Chagas disease testing and treatment are rarely followed for many reasons including a paucity of knowledge among providers. We aimed to determine if the number of Chagas tests performed increased after information sessions at a community health center. A secondary aim was to determine if there was a difference in number of tests performed by provider type. We found that the number of T. cruzi serologies performed in the ten months after information sessions increased significantly over that in the ten preceding months. Chagas testing increased across departments, though Chagas diagnostics were an extra and unmitigated time burden on clinicians. Increasing provider knowledge is a major step to increase diagnosis and treatment of this neglected disease, when clinicians are motivated by their inherent prosocial preferences including altruism i.e., by the positive impact of their work on patients’ lives.
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Affiliation(s)
- Helen Mahoney West
- Division of Infectious Disease Boston Children’s Hospital, Boston, Massachusetts, United States of America
- * E-mail:
| | - Carly E. Milliren
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | | | - Jillian Davis
- East Boston Neighborhood Health Center, Boston, Massachusetts, United States of America
| | - Jaime Gallegos
- East Boston Neighborhood Health Center, Boston, Massachusetts, United States of America
| | - Juan Huanuco Perez
- East Boston Neighborhood Health Center, Boston, Massachusetts, United States of America
| | - Julia R. Köhler
- Division of Infectious Disease Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
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King WR, Acosta‐Zaldivar M, Qi W, Cooke L, Cherico N, Köhler JR, Patton‐Vogt J. Two Pathways Diverge: Glycerophosphocholine Impacts Both Phosphate and Lipid Metabolism in
Candida albicans. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r5482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Maikel Acosta‐Zaldivar
- Division of Infectious DiseasesBoston Children's Hospital/Harvard Medical SchoolBostonMA
| | - Wanjun Qi
- Division of Infectious DiseasesBoston Children's Hospital/Harvard Medical SchoolBostonMA
| | | | | | - Julia R. Köhler
- Division of Infectious DiseasesBoston Children's Hospital/Harvard Medical SchoolBostonMA
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7
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Ding X, Kambara H, Guo R, Kanneganti A, Acosta-Zaldívar M, Li J, Liu F, Bei T, Qi W, Xie X, Han W, Liu N, Zhang C, Zhang X, Yu H, Zhao L, Ma F, Köhler JR, Luo HR. Inflammasome-mediated GSDMD activation facilitates escape of Candida albicans from macrophages. Nat Commun 2021; 12:6699. [PMID: 34795266 PMCID: PMC8602704 DOI: 10.1038/s41467-021-27034-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 10/25/2021] [Indexed: 12/11/2022] Open
Abstract
Candida albicans is the most common cause of fungal sepsis. Inhibition of inflammasome activity confers resistance to polymicrobial and LPS-induced sepsis; however, inflammasome signaling appears to protect against C. albicans infection, so inflammasome inhibitors are not clinically useful for candidiasis. Here we show disruption of GSDMD, a known inflammasome target and key pyroptotic cell death mediator, paradoxically alleviates candidiasis, improving outcomes and survival of Candida-infected mice. Mechanistically, C. albicans hijacked the canonical inflammasome-GSDMD axis-mediated pyroptosis to promote their escape from macrophages, deploying hyphae and candidalysin, a pore-forming toxin expressed by hyphae. GSDMD inhibition alleviated candidiasis by preventing C. albicans escape from macrophages while maintaining inflammasome-dependent but GSDMD-independent IL-1β production for anti-fungal host defenses. This study demonstrates key functions for GSDMD in Candida's escape from host immunity in vitro and in vivo and suggests that GSDMD may be a potential therapeutic target in C. albicans-induced sepsis.
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Affiliation(s)
- Xionghui Ding
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
- Department of Burn and Plastic Surgery, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China
| | - Hiroto Kambara
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Rongxia Guo
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, CAMS Key laboratory for prevention and control of hematological disease treatment related infection, Chinese Academy of Medical Sciences & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, China
| | - Apurva Kanneganti
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Maikel Acosta-Zaldívar
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Jiajia Li
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, CAMS Key laboratory for prevention and control of hematological disease treatment related infection, Chinese Academy of Medical Sciences & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, China
| | - Fei Liu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, CAMS Key laboratory for prevention and control of hematological disease treatment related infection, Chinese Academy of Medical Sciences & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, China
| | - Ting Bei
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Wanjun Qi
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Xuemei Xie
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Wenli Han
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Ningning Liu
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Cunling Zhang
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Xiaoyu Zhang
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Hongbo Yu
- VA Boston Healthcare System, Department of Pathology and Laboratory Medicine, 1400 VFW Parkway West Roxbury, Boston, MA, 02132, USA
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Li Zhao
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA
| | - Fengxia Ma
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, CAMS Key laboratory for prevention and control of hematological disease treatment related infection, Chinese Academy of Medical Sciences & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, China
| | - Julia R Köhler
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Hongbo R Luo
- Department of Pathology, Dana-Farber/Harvard Cancer Center, Harvard Medical School; Department of Laboratory Medicine, Boston Children's Hospital, Enders Research Building, Room 814, Boston, MA, 02115, USA.
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Mahoney West H, Milliren CE, Vragovic O, Köhler JR, Yarrington C. Perceived barriers to Chagas disease screening among a diverse group of prenatal care providers. PLoS One 2021; 16:e0246783. [PMID: 33635887 PMCID: PMC7909700 DOI: 10.1371/journal.pone.0246783] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/26/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Chagas disease is a vector borne infection of poverty endemic to Latin America which affects an estimated 40,000 women of child-bearing age in the United States (US). In the US Chagas disease is concentrated among individuals who have lived in endemic areas. Prenatal diagnosis and treatment are needed to prevent congenital transmission. The objective of this study was to assess perceived barriers to Chagas disease screening among prenatal care providers in Obstetrics/Gynecology and Family Medicine Departments of a tertiary care safety-net hospital caring for a significant at-risk population. METHODOLOGY/PRINCIPAL FINDINGS An anonymous survey was distributed to 178 Obstetrics/Gynecology and Family Medicine practitioners. Of the 66 respondents, 39% thought Chagas screening was very important, and 48% somewhat important as a public health initiative. One third judged screening patients during clinic visits as very important. Most respondents (64%) reported being familiar with Chagas disease. However, only 32% knew how to order a test and only 22% reported knowing what to do if a test was positive. CONCLUSIONS/SIGNIFICANCE These findings will be incorporated into measures to facilitate full implementation of Chagas screening, and can inform initiatives at other centers who wish to address this deeply neglected infection among their patient families. Greater integration of information on Chagas disease screening and treatment in medical and nursing education curricula can contribute to addressing this disease with the focus that its potentially fatal sequelae merit.
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Affiliation(s)
- Helen Mahoney West
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Simmons University School of Nursing, Boston, Massachusetts, United States of America
- * E-mail:
| | - Carly E. Milliren
- Institutional Centers for Clinical and Translational Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Olivera Vragovic
- Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Julia R. Köhler
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Christina Yarrington
- Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Obstetrics/Gynecology, Boston Medical Center, Boston, Massachusetts, United States of America
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9
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Piqueras A, Ganapathi L, Carpenter JF, Rubio T, Sandora TJ, Flett KB, Köhler JR. Trends in Pediatric Candidemia: Epidemiology, Anti-Fungal Susceptibility, and Patient Characteristics in a Children's Hospital. J Fungi (Basel) 2021; 7:jof7020078. [PMID: 33499285 PMCID: PMC7911199 DOI: 10.3390/jof7020078] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/13/2021] [Accepted: 01/19/2021] [Indexed: 12/26/2022] Open
Abstract
Candida bloodstream infections (CBSIs) have decreased among pediatric populations in the United States, but remain an important cause of morbidity and mortality. Species distributions and susceptibility patterns of CBSI isolates diverge widely between children and adults. The awareness of these patterns can inform clinical decision-making for empiric or pre-emptive therapy of children at risk for candidemia. CBSIs occurring from 2006-2016 among patients in a large children's hospital were analyzed for age specific trends in incidence rate, risk factors for breakthrough-CBSI, and death, as well as underlying conditions. Candida species distributions and susceptibility patterns were evaluated in addition to the anti-fungal agent use. The overall incidence rate of CBSI among this complex patient population was 1.97/1000 patient-days. About half of CBSI episodes occurred in immunocompetent children and 14% in neonatal intensive care unit (NICU) patients. Anti-fungal resistance was minimal: 96.7% of isolates were fluconazole, 99% were micafungin, and all were amphotericin susceptible. Liposomal amphotericin was the most commonly prescribed anti-fungal agent included for NICU patients. Overall, CBSI-associated mortality was 13.7%; there were no deaths associated with CBSI among NICU patients after 2011. Pediatric CBSI characteristics differ substantially from those in adults. The improved management of underlying diseases and antimicrobial stewardship may further decrease morbidity and mortality from CBSI, while continuing to maintain low resistance rates among Candida isolates.
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Affiliation(s)
- Anabel Piqueras
- Pediatric Infectious Disease Unit, Pediatrics Department, University & Polytechnic Hospital La Fe, E-46026 Valencia, Spain;
| | - Lakshmi Ganapathi
- Division of Infectious Diseases, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA; (L.G.); (J.F.C.); (T.J.S.); (K.B.F.)
| | - Jane F. Carpenter
- Division of Infectious Diseases, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA; (L.G.); (J.F.C.); (T.J.S.); (K.B.F.)
| | - Thomas Rubio
- Lombardi Cancer Center, Georgetown University Hospital, Washington, DC 20007, USA;
| | - Thomas J. Sandora
- Division of Infectious Diseases, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA; (L.G.); (J.F.C.); (T.J.S.); (K.B.F.)
| | - Kelly B. Flett
- Division of Infectious Diseases, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA; (L.G.); (J.F.C.); (T.J.S.); (K.B.F.)
| | - Julia R. Köhler
- Division of Infectious Diseases, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA; (L.G.); (J.F.C.); (T.J.S.); (K.B.F.)
- Correspondence:
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10
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Ganapathi L, Caldas A, Miranda J, Köhler JR, Visner G, Sawicki G. Medical Deferred Action - Living on Borrowed Time. N Engl J Med 2019; 381:1601-1603. [PMID: 31577869 DOI: 10.1056/nejmp1911907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lakshmi Ganapathi
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
| | - Adolfo Caldas
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
| | - Jacqueline Miranda
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
| | - Julia R Köhler
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
| | - Gary Visner
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
| | - Gregory Sawicki
- From the Division of Infectious Diseases (L.G., J.R.K.), the Division of Nephrology (L.G.), and the Division of Pulmonary Medicine (G.V., G.S.), Department of Pediatrics, Harvard Medical School, and the Division of Social Work (A.C., J.M.), the Cancer and Blood Disorders Center (J.M.), the Children's Hospital Primary Care Center (A.C.), and the Cystic Fibrosis Center (G.S.), Boston Children's Hospital - all in Boston
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11
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Santus W, Barresi S, Mingozzi F, Broggi A, Orlandi I, Stamerra G, Vai M, Martorana AM, Polissi A, Köhler JR, Liu N, Zanoni I, Granucci F. Skin infections are eliminated by cooperation of the fibrinolytic and innate immune systems. Sci Immunol 2017; 2:2/15/eaan2725. [PMID: 28939652 DOI: 10.1126/sciimmunol.aan2725] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/21/2017] [Accepted: 07/27/2017] [Indexed: 12/24/2022]
Abstract
Nuclear factor of activated T cells (NFAT) is activated in innate immune cells downstream of pattern recognition receptors, but little is known about NFAT's functions in innate immunity compared with adaptive immunity. We show that early activation of NFAT balances the two major phases of the innate response to Candida albicans skin infections: the protective containment (abscess) and the elimination (expulsion) phases. During the early containment phase, transforming growth factor-β (TGF-β) induces the deposit of collagen around newly recruited polymorphonuclear cells to prevent microbial spreading. During the elimination phase, interferon-γ (IFN-γ) blocks differentiation of fibroblasts into myofibroblasts by antagonizing TGF-β signaling. IFN-γ also induces the formation of plasmin that, in turn, promotes abscess capsule digestion and skin ulceration for microbial discharge. NFAT controls innate IFN-γ production and microbial expulsion. This cross-talk between the innate immune and the fibrinolytic systems also occurs during infection with Staphylococcus aureus and is a protective response to minimize tissue damage and optimize pathogen elimination.
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Affiliation(s)
- William Santus
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Simona Barresi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Francesca Mingozzi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Achille Broggi
- Harvard Medical School and Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ivan Orlandi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Giulia Stamerra
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Marina Vai
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Alessandra M Martorana
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Alessandra Polissi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Julia R Köhler
- Harvard Medical School and Division of Infectious Diseases, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ningning Liu
- Harvard Medical School and Division of Infectious Diseases, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ivan Zanoni
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy. .,Harvard Medical School and Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Boston, MA 02115, USA
| | - Francesca Granucci
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
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12
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Chowdhury T, Köhler JR. Ribosomal protein S6 phosphorylation is controlled by TOR and modulated by PKA in Candida albicans. Mol Microbiol 2015; 98:384-402. [PMID: 26173379 DOI: 10.1111/mmi.13130] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2015] [Indexed: 12/25/2022]
Abstract
TOR and PKA signaling pathways control eukaryotic cell growth and proliferation. TOR activity in model fungi, such as Saccharomyces cerevisiae, responds principally to nutrients, e.g., nitrogen and phosphate sources, which are incorporated into the growing cell mass; PKA signaling responds to the availability of the cells' major energy source, glucose. In the fungal commensal and pathogen, Candida albicans, little is known of how these pathways interact. Here, the signal from phosphorylated ribosomal protein S6 (P-S6) was defined as a surrogate marker for TOR-dependent anabolic activity in C. albicans. Nutritional, pharmacologic and genetic modulation of TOR activity elicited corresponding changes in P-S6 levels. The P-S6 signal corresponded to translational activity of a GFP reporter protein. Contributions of four PKA pathway components to anabolic activation were then examined. In high glucose concentrations, only Tpk2 was required to upregulate P-S6 to physiologic levels, whereas all four tested components were required to downregulate P-S6 in low glucose. TOR was epistatic to PKA components with respect to P-S6. In many host niches inhabited by C. albicans, glucose is scarce, with protein being available as a nitrogen source. We speculate that PKA may modulate TOR-dependent cell growth to a rate sustainable by available energy sources, when monomers of anabolic processes, such as amino acids, are abundant.
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Affiliation(s)
- Tahmeena Chowdhury
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
| | - Julia R Köhler
- Division of Infectious Diseases, Boston Children's Hospital/Harvard Medical School, Boston, MA, 02115, USA
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13
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Abstract
Few among the millions of fungal species fulfill four basic conditions necessary to infect humans: high temperature tolerance, ability to invade the human host, lysis and absorption of human tissue, and resistance to the human immune system. In previously healthy individuals, invasive fungal disease is rare because animals' sophisticated immune systems evolved in constant response to fungal challenges. In contrast, fungal diseases occur frequently in immunocompromised patients. Paradoxically, successes of modern medicine have put increasing numbers of patients at risk for invasive fungal infections. Uncontrolled HIV infection additionally makes millions vulnerable to lethal fungal diseases. A concerted scientific and social effort is needed to meet these challenges.
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Affiliation(s)
- Julia R Köhler
- Division of Infectious Diseases, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Arturo Casadevall
- Departments of Microbiology and Immunology and Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine, New York, New York 10461
| | - John Perfect
- Division of Infectious Diseases, Duke Medical Center, Durham, North Carolina 27710
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14
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Affiliation(s)
- Julia R Köhler
- Division of Infectious Disease, Boston Children's Hospital, Boston, Massachusetts
| | - Martha Sola-Visner
- Division of Neonatal Medicine, Boston Children's Hospital, Boston, Massachusetts
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15
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Koh AY, Köhler JR, Coggshall KT, Van Rooijen N, Pier GB. Mucosal damage and neutropenia are required for Candida albicans dissemination. PLoS Pathog 2008; 4:e35. [PMID: 18282097 PMCID: PMC2242836 DOI: 10.1371/journal.ppat.0040035] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 01/07/2008] [Indexed: 01/17/2023] Open
Abstract
Candida albicans fungemia in cancer patients is thought to develop from initial gastrointestinal (GI) colonization with subsequent translocation into the bloodstream after administration of chemotherapy. It is unclear what components of the innate immune system are necessary for preventing C. albicans dissemination from the GI tract, but we have hypothesized that both neutropenia and GI mucosal damage are critical for allowing widespread invasive C. albicans disease. We investigated these parameters in a mouse model of C. albicans GI colonization that led to systemic spread after administration of immunosuppression and mucosal damage. After depleting resident GI intestinal flora with antibiotic treatment and achieving stable GI colonization levels of C. albicans, it was determined that systemic chemotherapy with cyclophosphamide led to 100% mortality, whereas selective neutrophil depletion, macrophage depletion, lymphopenia or GI mucosal disruption alone resulted in no mortality. Selective neutrophil depletion combined with GI mucosal disruption led to disseminated fungal infection and 100% mortality ensued. GI translocation and dissemination by C. albicans was also dependent on the organism's ability to transform from the yeast to the hyphal form. This mouse model of GI colonization and fungemia is useful for studying factors of innate host immunity needed to prevent invasive C. albicans disease as well as identifying virulence factors that are necessary for fungal GI colonization and dissemination. The model may also prove valuable for evaluating therapies to control C. albicans infections.
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Affiliation(s)
- Andrew Y Koh
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
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16
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Abstract
A dominant selectable marker for Candida albicans and other Candida species, which confers resistance to nourseothricin, was characterized. In a heterologous promoter system and a recyclable cassette, the marker efficiently permitted deletion and complementation of C. albicans genes. Neither growth nor filamentous development was affected in strains expressing this marker.
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Affiliation(s)
- Junqing Shen
- Division of Infectious Disease, Enders 7, Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA
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17
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Kottom TJ, Köhler JR, Thomas CF, Fink GR, Limper AH. Lung epithelial cells and extracellular matrix components induce expression of Pneumocystis carinii STE20, a gene complementing the mating and pseudohyphal growth defects of STE20 mutant yeast. Infect Immun 2003; 71:6463-71. [PMID: 14573668 PMCID: PMC219549 DOI: 10.1128/iai.71.11.6463-6471.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2003] [Revised: 04/21/2003] [Accepted: 08/11/2003] [Indexed: 11/20/2022] Open
Abstract
Pneumocystis carinii causes severe pneumonia in immunocompromised hosts. The binding of P. carinii to alveolar epithelial cells and extracellular matrix constituents such as fibronectin and vitronectin is a central feature of infection, which initiates proliferation of the organism. Herein, we demonstrate that P. carinii binding to lung cells specifically alters the gene expression of the organism, regulating fungal growth. Subtractive hybridization was performed to isolate P. carinii genes expressed following binding to mammalian extracellular matrix constituents. P. carinii STE20 (PCSTE20), a gene participating in mating and pseudohyphal growth of other fungi, was identified following adherence to the extracellular matrix constituents fibronectin, vitronectin, collagen, and lung epithelial cells. The expression of PCSTE20 and a related P. carinii mitogen-activated protein kinase (MAPK) kinase gene, also implicated in signaling of mating, were both specifically upregulated by binding to matrix protein. The expression of general cyclin-dependent kinases and other MAPKs not involved in mating pathways were not altered by organism binding. PCSTE20 expression was also strongly enhanced following organism attachment to A549 lung epithelial cells. When expressed in a Saccharomyces cerevisiae ste20Delta mutant, PCSTE20 suppressed defects in both mating and pseudohyphal growth. These findings are consistent with the observed proliferation and filopodial extension of Pneumocystis organisms adherent to the epithelium in the lungs of immunocompromised hosts. PCSTE20 expression appears to represent a significant component in the regulation of the life cycle of this intractable opportunistic pathogen.
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Affiliation(s)
- Theodore J Kottom
- Departments of Internal Medicine and Biochemistry, Mayo Clinic and Foundation, Rochester, Minnesota, USA
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18
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Abstract
Early pseudohyphal growth of Saccharomyces cerevisiae is well described, and is known to be subject to a complex web of developmental regulation. In maturing filaments, young cells differ significantly from their pseudohyphal progenitors, in their shape, and in their timing and direction of cell division. The changes that occur during filament maturation result in round and oval cells surrounding and covering the pseudohyphal filament. In a screen for mutants that affect this process, a vacuolar protein sorting gene, MOS10 (VPS60), and a gene encoding an alpha subunit of the proteasome core, PRE9, were isolated. Characterization of the mos10/mos10 phenotype showed that the process of filament maturation is regulated differently from early filamentous growth, and that the requirement for Mos10 is limited to the maturation stage of pseudohyphal development. The mos10/mos10 phenotype is unlikely to be an unspecific effect of disruption of endocytosis or vacuolar protein sorting, because it is not recapitulated by mutants in other genes required for these processes. Disruption of homologues of MOS10, which act as components of the ESCRT-III complex in targeting proteins for vacuolar degradation, results in abnormal early pseudohyphal growth, not in the filament maturation defect seen in mos10/mos10. Thus, Mos10 may function in targeting of specific cargo proteins for degradation, under conditions particular to maturing filaments.
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Affiliation(s)
- Julia R Köhler
- Division of Infectious Disease, Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA.
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19
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Orange JS, Brodeur SR, Jain A, Bonilla FA, Schneider LC, Kretschmer R, Nurko S, Rasmussen WL, Köhler JR, Gellis SE, Ferguson BM, Strominger JL, Zonana J, Ramesh N, Ballas ZK, Geha RS. Deficient natural killer cell cytotoxicity in patients with IKK-γ/NEMO mutations. J Clin Invest 2002. [DOI: 10.1172/jci0214858] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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20
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Orange JS, Brodeur SR, Jain A, Bonilla FA, Schneider LC, Kretschmer R, Nurko S, Rasmussen WL, Köhler JR, Gellis SE, Ferguson BM, Strominger JL, Zonana J, Ramesh N, Ballas ZK, Geha RS. Deficient natural killer cell cytotoxicity in patients with IKK-gamma/NEMO mutations. J Clin Invest 2002; 109:1501-9. [PMID: 12045264 PMCID: PMC150995 DOI: 10.1172/jci14858] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
NF-kappaB essential modifier (NEMO), also known as IKK-gamma, is a member of the I-kappaB kinase complex responsible for phosphorylating I-kappaB, allowing the release and activation of NF-kappaB. Boys with an expressed NEMO mutation have an X-linked syndrome characterized by hypohidrotic ectodermal dysplasia with immune deficiency (HED-ID). The immunophenotype resulting from NEMO mutation is highly variable, with deficits in both T and B cell responses. We evaluated three patients with NEMO mutations (L153R, Q403X, and C417R) and HED-ID who had evidence of defective CD40 signaling. All three patients had normal percentages of peripheral blood NK cells, but impaired NK cell cytotoxic activity. This was not due to a generalized defect in cytotoxicity because antibody-dependent cellular cytotoxicity was intact. This abnormality was partially reversed by in vitro addition of IL-2, which was also able to induce NF-kappaB activation. In one patient with recurrent cytomegalovirus infections, administration of IL-2 partially corrected the NK cell killing deficit. These data suggest that NEMO participates in signaling pathways leading to NK cell cytotoxicity and that IL-2 can activate NF-kappaB and partially overcome the NK cell defect in patients with NEMO mutations.
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Affiliation(s)
- Jordan S Orange
- Division of Immunology, Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA
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21
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Köhler JR, Maiwald M, Lück PC, Helbig JH, Hingst V, Sonntag HG. Detecting legionellosis by unselected culture of respiratory tract secretions and developing links to hospital water strains. J Hosp Infect 1999; 41:301-11. [PMID: 10392336 DOI: 10.1053/jhin.1998.0517] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For a 13-month period, all respiratory tract secretions submitted for routine bacteriology from a large hospital complex were cultured for legionella, irrespective of clinical diagnosis and laboratory requests. Ten cases of legionellosis were detected in this manner, three of which met a strict epidemiological definition of hospital-acquired. Therefore, the 16 warm-water systems of the hospitals, spread out over two locations, were examined for the presence of legionella. Legionella pneumophila was found in 15 warm water systems, with a distinct pattern of serogroups between the two locations. Legionella of the same serogroups as those isolated from patients were present in each hospital water supply. The isolates were further typed by monoclonal antibodies and by genomic macrorestriction analysis. Similarity between clinical and environmental isolates was found in seven cases. In these cases, acquisition from the hospital water supply appears very likely. The strains of the remaining three patients did not match those in hospital water, suggesting that community-acquired legionellosis was occurring as well. This study suggests that routinely culturing respiratory tract secretions of pneumonia patients for legionella can help diagnose unsuspected cases of legionellosis. Typing legionella strains beyond the serogroup level with tools such as macrorestriction analysis is useful to define sources of infection, which can then be targeted for control measures.
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Affiliation(s)
- J R Köhler
- Hygiene-Institut der Universität, Abteilung Hygiene und Medizinische Mikrobiologie, Heidelberg, Germany
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22
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Abstract
Candida albicans and Saccharomyces cerevisiae switch from a yeast to a filamentous form. In Saccharomyces, this switch is controlled by two regulatory proteins, Ste12p and Phd1p. Single-mutant strains, ste12/ste12 or phd1/phd1, are partially defective, whereas the ste12/ste12 phd1/phd1 double mutant is completely defective in filamentous growth and is noninvasive. The equivalent cph1/cph1 efg1/efg1 double mutant in Candida (Cph1p is the Ste12p homolog and Efg1p is the Phd1p homolog) is also defective in filamentous growth, unable to form hyphae or pseudohyphae in response to many stimuli, including serum or macrophages. This Candida cph1/cph1 efg1/efg1 double mutant, locked in the yeast form, is avirulent in a mouse model.
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Affiliation(s)
- H J Lo
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge 02142, USA
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23
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Köhler JR, Fink GR. Candida albicans strains heterozygous and homozygous for mutations in mitogen-activated protein kinase signaling components have defects in hyphal development. Proc Natl Acad Sci U S A 1996; 93:13223-8. [PMID: 8917572 PMCID: PMC24074 DOI: 10.1073/pnas.93.23.13223] [Citation(s) in RCA: 248] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/1996] [Indexed: 02/03/2023] Open
Abstract
The Candida albicans genes, CST20 and HST7, were cloned by their ability to suppress the mating defects of Saccharomyces cerevisiae mutants in the ste20 and ste7 genes, which code for elements of the mating mitogenactivated protein (MAP) kinase pathway. These Candida genes are both structural and functional homologs of the cognate Saccharomyces genes. The pattern of suppression in Saccharomyces is related to their presumptive position in the MAP kinase cascade. Null alleles of these genes were constructed in Candida. The Candida homozygous null mutants are defective in hyphal formation on some media, but are still induced to form hyphae by serum, showing that serum induction of hyphae is independent of the MAP kinase cascade. The Candida heterozygotes CST20/cst20 and HST7/hst7 are also defective in hyphal formation. This lack of dominance of the wild-type allele suggests that gene dosage is important in Candida.
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Affiliation(s)
- J R Köhler
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
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