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Opportunistic Fungi (opportunistic + fungus)

Distribution by Scientific Domains

Medical Sciences	60%
Life Sciences	40%

Selected Abstracts

In vitro response to Candida albicans in cultures of whole human blood from young and aged donors

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2007
Celia Murciano
Abstract Invasive infections with opportunistic fungi, such as Candida albicans, have become an increasing problem in aged adults in recent years. This work investigates the influence of human ageing on C. albicans recognition by toll-like receptors (TLRs), essential components of the innate immune system, using a cohort of 96 young (15,42 years) and aged (>70 years) human volunteers. No significant differences between aged and young donors were observed on (1) cell surface TLR2, TLR6 and TLR4 expression on lymphocytes, monocytes and granulocytes, (2) production of cytokines [IL-8, IL-1,, IL-6, IL-10, tumour necrosis factor (TNF)-, and IL-12p70] and prostaglandin E2 (PGE2) by whole human blood in response to C. albicans and (3) fungicidal activity of whole blood. A statistically significant higher titre of natural anti- C. albicans antibodies was found in plasma of volunteers between 80 and 95 years old when compared with other age groups, probably as a consequence of the increased levels of serum Ig that has been described in elderly subjects. Therefore, the results indicate that the increased susceptibility to C. albicans infections in the elderly is not a consequence of defects in TLRs expression or signalling, nor of an impaired fungicidal activity of blood. [source]

Herpes simplex virus type 1 dysregulates anti-fungal defenses preventing monocyte activation and downregulating toll-like receptor-2

MICROBIOLOGY AND IMMUNOLOGY, Issue 12 2008
Claudio Cermelli
ABSTRACT We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP-1 monocytic cell line is first infected with HSV-1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV-1-infected THP-1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL-12 production was also observed. Cytofluorimetric analysis showed that HSV-1-infected monocytes exhibit: (i) downregulated TLR-2 and TLR-4, critical structures in fungal recognition; (ii) reduced expression of CD38 and CD69, known to be important markers of monocyte activation; and (iii) enhanced expression of apoptosis and necrosis markers, in the absence of altered cell proliferation. Overall, these findings imply that HSV-1 infection prevents monocyte activation, thus leading to a significant dysfunction of the monocyte-mediated anti- Candida response; HSV-1 induced apoptosis and necrosis of monocytes further contribute to this impairment. [source]

The incidence of opportunistic fungi in patients suspected of tuberculosis

MYCOSES, Issue 7-8 2000
M. Chadeganipour
Summary The incidence of opportunistic fungi in bronchoalveolar lavage specimens from patients suspected of tuberculosis in Isfahan, Iran, was determined. From 200 patients 36 yeasts (18%) and seven filamentous fungi (3.5%) were isolated. Out of 44 patients who had fungal infections, 12 cases were affected with definite tuberculosis. [source]

Phytophthora pinifolia sp. nov. associated with a serious needle disease of Pinus radiata in Chile

PLANT PATHOLOGY, Issue 4 2008
A. Durán
During the course of the past three years, a new disease of Pinus radiata, referred to as ,Daño Foliar del Pino' (DFP) has appeared in the Arauco province of Chile and subsequently spread to other areas. The disease is typified by needle infections, exudation of resin at the bases of the needle brachyblasts and, in younger trees, necrotic lesions in the cambium, which eventually girdle the branches. The disease causes the death of young seedlings and mature trees can also succumb after a few years of successive infection, probably hastened by opportunistic fungi such as Diplodia pinea. Isolations on selective medium for Phytophthora spp. led to the consistent isolation of a Phytophthora sp. from needle tissue. DNA sequence comparisons for the ITS rDNA and cox II gene regions, and morphological observation showed that this oomycete represents a previously undescribed species for which the name Phytophthora pinifolia sp. nov. is provided. This new species is characterized by unbranched sporangiophores, and non-papillate, sub-globose to ovoid sporangia that are occasionally free from the sporangiophore with medium length pedicels. Despite using a number of oospore inducing techniques, oogonia/antheridia were not observed in isolates of P. pinifolia. Pathogenicity trials with P. pinifolia showed that it is pathogenic to P. radiata and causes rapid death of the succulent apical parts of young plants. Phytophthora pinifolia is the first Phytophthora known to be associated with needles and shoots of a Pinus sp. and its aerial habit is well matched with the occurrence and symptoms of DFP in Chile. [source]