Se realizó microscopía electrónica de barrido ambiental (ESEM) en plántulas de maracuyá (Passiflora edulis f. flavicarpa) inoculadas con Fusarium solani f. sp. passiflorae (teleomorfo: Haematonectria ...haematococca) agente causal de la secadera. Las inoculaciones se realizaron cada 24 h hasta el séptimo día y hasta el día quince el intervalo fue de 72 h. El aislamiento en medio de papa (PDA) se colocó sobre el cuello de la raíz mediante la metodología de cribado en tubos de ensayo modificada. La superficie del cuello, tallo, hojas y secciones longitudinales del cuello y tallo fueron observadas. Después de 24 h de la inoculación, se observaron conidios y micelio denso septado sobre la epidermis del tallo y el cuello e hipertrofia y degradación de la pared celular de los tejidos vasculares. Al quinto día se formaron macroconidios a partir de monofiálides en el micelio aéreo en el tallo. Diez días después, las células del xilema y médula del cuello fueron colonizadas por hifas, esporodoquios maduros e inclusiones. La colonización de las estomas por las hifas comenzó seis días después de la inoculación y trece días después de la inoculación se observaron monofiálides con microconidios in situ sobre la superficie foliar. Basados en la evidencia y estudios previos, la colonización interna por hifas de F. solani f. sp. passiflorae se concentra en el área del cuello y los daños de las células indican una actividad enzimática extracelular del hongo. El periodo de incubación y latencia de F. solani f. sp. passiflorae fue de 1,4 y 4 días, respectivamente.
Background Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by inborn errors of the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex. From the first ...year of life onward, most affected patients display multiple, severe, and recurrent infections caused by bacteria and fungi. Mycobacterial infections have also been reported in some patients. Objective Our objective was to assess the effect of mycobacterial disease in patients with CGD. Methods We analyzed retrospectively the clinical features of mycobacterial disease in 71 patients with CGD. Tuberculosis and BCG disease were diagnosed on the basis of microbiological, pathological, and/or clinical criteria. Results Thirty-one (44%) patients had tuberculosis, and 53 (75%) presented with adverse effects of BCG vaccination; 13 (18%) had both tuberculosis and BCG infections. None of these patients displayed clinical disease caused by environmental mycobacteria, Mycobacterium leprae , or Mycobacterium ulcerans . Most patients (76%) also had other pyogenic and fungal infections, but 24% presented solely with mycobacterial disease. Most patients presented a single localized episode of mycobacterial disease (37%), but recurrence (18%), disseminated disease (27%), and even death (18%) were also observed. One common feature in these patients was an early age at presentation for BCG disease. Mycobacterial disease was the first clinical manifestation of CGD in 60% of these patients. Conclusion Mycobacterial disease is relatively common in patients with CGD living in countries in which tuberculosis is endemic, BCG vaccine is mandatory, or both. Adverse reactions to BCG and severe forms of tuberculosis should lead to a suspicion of CGD. BCG vaccine is contraindicated in patients with CGD.
Talaromycosis (penicilliosis) is a major fungal disease endemic across a narrow band of tropical countries of South and Southeast Asia. The etiologic agent is a thermally dimorphic fungus
Talaromyces
...(
Penicillium
)
marneffei
, which was first isolated from a bamboo rat in Vietnam in 1956, but no formal description was published. In 1959, Professor Gabriel Segretain formally described it as a novel species
Talaromyces
(
Penicillium
)
marneffei
, and the human pathogenic potential of the fungus in
Mycopathologia
. The first natural human case of talaromycosis (penicillosis) was reported in 1973 and involved an American minister with Hodgkin’s disease who lived in Southeast Asia. Sixty years after the discovery of the pathogen, talaromycosis caused by
T. marneffei
is recognized as an important human disease with the potential to cause high mortality in the absence of proper diagnosis and prompt treatment. Talaromycosis remains a significant infectious complication in HIV/AIDS patients and in patients with other immune defects. The disease is being recognized with an increasing frequency well beyond the traditional endemic areas. The natural reservoirs of
T. marneffei
in wild rodents are well-defined, which links the ecology with the epidemiology of talaromycosis in endemic areas. There is an urgent unmet need for rapid and affordable point-of-care diagnostic tests. We also need more clinical studies to define the best therapeutic options for the management of talaromycosis patients.
The recent rate of emergence of pathogenic fungi that are resistant to the limited number of commonly used antifungal agents is unprecedented. The azoles, for example, are used not only for human and ...animal health care and crop protection but also in antifouling coatings and timber preservation. The ubiquity and multiple uses of azoles have hastened the independent evolution of resistance in many environments. One consequence is an increasing risk in human health care from naturally occurring opportunistic fungal pathogens that have acquired resistance to this broad class of chemicals. To avoid a global collapse in our ability to control fungal infections and to avoid critical failures in medicine and food security, we must improve our stewardship of extant chemicals, promote new antifungal discovery, and leverage emerging technologies for alternative solutions.
Fungal infections throughout the world appear to be increasing. This may in part be due to the increase in the population of patients that are susceptible to otherwise rare fungal infections ...resulting from the use of immune modulating procedures such as hematopoietic stem cell transplants and drugs like tissue necrosis factor antagonists. Histoplasma capsulatum, an endemic fungus throughout North and South America, is reemerging among HIV+ patients in Central and South America and among patients taking tissue necrosis factor antagonists and other biologics in North America. Fusarium species, a relatively rare fungal infection, is reemerging worldwide in the immunocompromised populations, especially those who are neutropenic like hematopoietic stem cell transplant recipients. A new yeast species is currently emerging worldwide: Candida auris, unknown just a decade ago. It is causing large healthcare-associated outbreaks on four continents and is spreading throughout the world through patient travel. In this review the epidemiology, pathology, detection and treatment of these three emerging and reemerging fungi will be discussed.
Tackling human fungal infections Brown, Gordon D; Denning, David W; Levitz, Stuart M
Science,
2012-May-11, 2012-05-11, 20120511, Letnik:
336, Številka:
6082
Journal Article
Recenzirano
Odprti dostop
Fungi infect billions of people every year, yet their contribution to the global burden of disease is largely unrecognized. Most are "relatively" minor infections, but millions contract diseases that ...kill at least as many people as tuberculosis or malaria. Although true mortality rates are unknown because of a lack of good epidemiological data, the incidence of invasive fungal infections is rising as a result of modern medical interventions and immunosuppressive diseases, such as AIDS. Despite the high mortality rates of invasive fungal infections, they remain understudied and underdiagnosed as compared with other infectious diseases. What can be done to remedy this unfortunate situation?
Fungal disease is an increasingly recognised global clinical challenge associated with high mortality. Early diagnosis of fungal infection remains problematic due to the poor sensitivity and ...specificity of current diagnostic modalities. Advances in sequencing technologies hold promise in addressing these shortcomings and for improved fungal detection and identification. To translate such emerging approaches into mainstream clinical care will require refinement of current sequencing and analytical platforms, ensuring standardisation and consistency through robust clinical benchmarking and its validation across a range of patient populations. In this state-of-the-art review, we discuss current diagnostic and therapeutic challenges associated with fungal disease and provide key examples where the application of sequencing technologies has potential diagnostic application in assessing the human ‘mycobiome’. We assess how ready access to fungal sequencing may be exploited in broadening our insight into host–fungal interaction, providing scope for clinical diagnostics and the translation of emerging mycobiome research into clinical practice.
•SARS-CoV-2, the cause of COVID19 disease, has spread globally since late 2019•Bacterial coinfections associated with mortality in previous influenza pandemics•Proportion of COVID19 patients with ...bacterial coinfection less than in flu pandemics•Higher proportion of critically-ill with bacterial coinfections than in mixed setting•Bacterial co-pathogen profiles different to those in influenza co-infections•Fungal coinfection diagnosis difficult so high level suspicion in critically-ill
In previous influenza pandemics, bacterial co-infections have been a major cause of mortality. We aimed to evaluate the burden of co-infections in patients with COVID-19.
We systematically searched Embase, Medline, Cochrane Library, LILACS and CINAHL for eligible studies published from 1 January 2020 to 17 April 2020. We included patients of all ages, in all settings. The main outcome was the proportion of patients with a bacterial, fungal or viral co-infection. .
Thirty studies including 3834 patients were included. Overall, 7% of hospitalised COVID-19 patients had a bacterial co-infection (95% CI 3-12%, n=2183, I2=92·2%). A higher proportion of ICU patients had bacterial co-infections than patients in mixed ward/ICU settings (14%, 95% CI 5-26, I2=74·7% versus 4%, 95% CI 1-9, I2= 91·7%). The commonest bacteria were Mycoplasma pneumonia, Pseudomonas aeruginosa and Haemophilus influenzae. The pooled proportion with a viral co-infection was 3% (95% CI 1-6, n=1014, I2=62·3%), with Respiratory Syncytial Virus and influenza A the commonest. Three studies reported fungal co-infections.
A low proportion of COVID-19 patients have a bacterial co-infection; less than in previous influenza pandemics. These findings do not support the routine use of antibiotics in the management of confirmed COVID-19 infection.
Phaeohyphomycosis refers to infections caused by darkly pigmented fungi. These fungi rarely cause life-threatening disease. We reviewed 101 cases of culture-proven primary central nervous system ...phaeohyphomycosis reported in the English-language literature from 1966 to 2002. The most frequently isolated species was Cladophialophora bantiana. The next most frequent isolate was Ramichloridium mackenziei, seen exclusively in patients from the Middle East. More than one-half of the cases occurred in patients with no known underlying immunodeficiency. Mortality rates were high regardless of immune status. Therapy is not standardized, although the combination of amphotericin B, flucytosine, and itraconazole may improve survival rates. Newer azoles, such as voriconazole, also have a broad spectrum of activity against these fungi, although clinical experience is limited. Complete excision of brain lesions may provide better results than simple aspiration. An aggressive medical and surgical approach is warranted in treating these infections to optimize outcomes.
The microbial coinfection in COVID-19 Chen, Xi; Liao, Binyou; Cheng, Lei ...
Applied microbiology and biotechnology,
09/2020, Letnik:
104, Številka:
18
Journal Article
Recenzirano
Odprti dostop
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel β-coronavirus, is the main pathogenic agent of the rapidly spreading pneumonia called coronavirus disease 2019 (COVID-19). ...SARS-CoV-2 infects much more people, especially the elder population, around the world than other coronavirus, such as SARS-CoV and MERS-CoV, which is challenging current global public health system. Beyond the pathogenesis of SARS-CoV-2, microbial coinfection plays an important role in the occurrence and development of SARS-CoV-2 infection by raising the difficulties of diagnosis, treatment, prognosis of COVID-19, and even increasing the disease symptom and mortality. We summarize the coinfection of virus, bacteria and fungi with SARS-CoV-2, their effects on COVID-19, the reasons of coinfection, and the diagnosis to emphasize the importance of microbial coinfection in COVID-19.
Key points
•
Microbial coinfection is a nonnegligible factor in COVID-19.
•
Microbial coinfection exacerbates the processes of the occurrence, development and prognosis of COVID-19, and the difficulties of clinical diagnosis and treatment.
•
Different virus, bacteria, and fungi contributed to the coinfection with SARS-CoV-2.
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