Different susceptibilities of yeasts and conidia of<i>Penicillium marneffei</i>to nitric oxide (NO)-mediated fungicidal activity of murine macrophages

Kudeken, Norifumi; Kawakami, Kazuyoshi; Saitô, Atsushi

doi:10.1046/j.1365-2249.1998.00565.x

Cited by 39 publications

(43 citation statements)

References 46 publications

(54 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect was more clearly related to the induction of iNOS in the former cells than that in the latter cells. However, in both cases, it could be mimicked by SNP addition, confirming the important anti-P. marneffei activity of reactive nitrogen intermediates (3,8).…”

mentioning

confidence: 56%

“…Macrophages and T lymphocytes play a central role in host resistance to P. marneffei (7). We and others recently reproduced in vitro at 37°C the intracellular growth of P. marneffei as yeast and showed that activated J774 macrophages inhibit yeast transformation of P. marneffei conidia by the secretion of NO (3,8). In view of the interplay between NO and iron, we studied the role of iron on (i) the in vitro growth requirement of P. marneffei and (ii) the fungicidal activity of activated human and mouse macrophages.…”

mentioning

confidence: 97%

See 1 more Smart Citation

Effects of Iron on Extracellular and Intracellular Growth of Penicillium marneffei

et al. 2000

View full text Add to dashboard Cite

Killing of intracellularPenicillium marneffei conidia is demonstrated in gamma interferon-lipopolysaccharide-activated human THP1 and mouse J774 cells. Iron overload significantly reduces the antifungal activity of macrophages. Likewise, exogenous iron enhances and iron chelators inhibit the extracellular growth of P. marneffei. These results suggest that iron availability critically affects immunity to and the pathogenicity of P. marneffei.

show abstract

mentioning

confidence: 56%

mentioning

confidence: 97%

Effects of Iron on Extracellular and Intracellular Growth of Penicillium marneffei

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Five isolates of P. marneffei were isolated from the lungs of 10 bamboo rats. P. marneffei was identified by the appearance of the fungal colonies on Sabouraud dextrose agar at 25°C and by microscopic examination (9).…”

mentioning

confidence: 99%

In Vitro Antifungal-Drug Susceptibilities of Mycelial and Yeast Forms of Penicillium marneffei Isolates in Cambodia

et al. 2006

View full text Add to dashboard Cite

Penicillium marneffei infection is an important disease among human immunodeficiency virus patients inPenicillium marneffei, the only known dimorphic species in the genus Penicillium, was first isolated from an organ of a bamboo rat (Rhizomyces sinensis or Rhizomyces pruinosis) (2). Penicilliosis marneffei has been recognized with increasing frequency in Southeast Asia and Southern China (15,19,20). P. marneffei infection has become the third most common opportunistic infection in AIDS patients in Southeast Asia (17,22). Penicilliosis marneffei was first reported in Cambodia in 2002 (1). We report in vitro susceptibility test results, as determined using Etest strips, for P. marneffei isolates from human immunodeficiency virus-infected patients who presented with disseminated P. marneffei infections. We include the susceptibility test results for P. marneffei isolates from the organs of bamboo rats. Our study is the first from Cambodia to report in vitro susceptibilities of clinical and bamboo rat isolates of P. marneffei to antifungal agents.P. marneffei was isolated from 29 human immunodeficiency virus-infected patients seen at Preah Bat Norodom Sihanouk Hospital, Phnom Penh, Cambodia, from 2002 to 2004. Thirteen P. marneffei isolates were isolated from blood, 12 from skin biopsy specimens, and 4 from respiratory specimens. In all cases, only one specimen type was submitted to the laboratory. Bamboo rats (Rhizomyces pruinosus) were captured in the Mondulkiri province of Cambodia. Five isolates of P. marneffei were isolated from the lungs of 10 bamboo rats. P. marneffei was identified by the appearance of the fungal colonies on Sabouraud dextrose agar at 25°C and by microscopic examination (9).One-week-old slant cultures of the mycelial form on Sabouraud dextrose agar, grown at 25°C, were flooded with deionized distilled water (10 ml/slant), and each slant was scraped with a sterile inoculation wire loop. The suspension of mycelial fragments and conidia was transferred to a glass grinder. After the grinding, a homogenous suspension was adjusted to 1 McFarland standard (11,14). To obtain inocula of the yeast form, brain heart infusion broth (Difco) was inoculated with a fungal suspension prepared from 7-dayold slant cultures. The inoculated brain heart infusion flasks were placed on a water bath shaker (150 rpm) and incubated at 37°C for 7 days, yielding a uniform growth of yeast cells. After incubation, the broth cultures were centrifuged at 15,000 ϫ g for 20 min (4°C). After the broth was discarded, the sediment was washed three times successively with sterile deionized distilled water. The washed yeast cells were suspended in deionized distilled water and adjusted to 1 McFarland standard. Etest strips (AB Biodisk, Solna, Sweden) containing amphotericin B (AMB) (0.002 to 32 g/ml), flucytosine (5FC) (0.002 to 32 g/ml), fluconazole (FLC) (0.016 to 256 g/ml), itraconazole (ITC) (0.002 to 32 g/ ml), and ketoconazole (KTC) (0.002 to 32 g/ml) were used to determine the MICs according to the manufacturer's instructio...

show abstract

“…Previously, BHI medium was commonly used to generate P. marneffei yeast cells 6,7 . These cells develop via arthroconidiation, a process whereby conidia differentiate to hyphal cells that subsequently divide into arthroconidia by septal (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, its transition ability was investigated daily when 1% peptone was added to the YNB supplemented with 0.1%, 0.5%, 1%, 2%, or 4% glucose and to the YNB supplemented with 1 mM, 2.5 mM, 5 mM, or 10 mM GlcNAc. 7 conidia were inoculated into a 250-ml flat bottom flask containing 50 ml of the tested liquid media. The culture was incubated in a gyratory shaker (New Brunswick Scientific Co., Inc.) at 37°C, 120 rpm.…”

Section: Preparation Of Inoculum Preparation Of Inoculum Preparation mentioning

confidence: 99%

Untitled

Tongchusak¹,

Pongsunk²,

Watkins³

et al. 2006

ScienceAsia

View full text Add to dashboard Cite

Penicillium marneffei is a dimorphic pathogenic fungus responsible for opportunistic infection in HIV infected individuals. The fungus displays dimorphic switching in response to temperature changes. At 25°C, it grows in mold form that produces penicilli conidia which are thought to be infectious. At 37°C, the fungus transforms into a fission yeast. To investigate this morphological conversion, P. marneffei conidia were grown in media supplemented with various organic substances. Sabouraud dextrose broth (SDB) supplemented with 4% yeast extract enhanced regular fission yeast production, whereas SDB alone and SDB supplemented with fetal bovine serum did not produce homogeneous cultures. The fungus in Sabouraud maltose broth exhibited filamentous hyphae, while its growth in Sabouraud galactose broth was inhibited. Yeast nitrogen base (YNB) medium supplemented with glucose gave hyphal growth and supplemented with N-acetylglucosamine (GlcNAc) gave retarded growth with multiseptate hyphae. Conidia-yeast conversion was not observed in YNB supplemented with glucose plus various amino acids. However, when 1% peptone was added to these YNB media, however, yeast cells or short multi-septate hyphae were produced. Surprisingly, conidia cultivated in distilled water containing 1% peptone gave uniform fission yeast similar to yeast cells found in clinical specimens. Thus, 1% peptone supplementation was responsible for the yeast transition and will serve as simple method to obtain pure P. marneffei yeasts for future studies on virulence, invasiveness, and pathogenesis.

show abstract

Different susceptibilities of yeasts and conidia ofPenicillium marneffeito nitric oxide (NO)-mediated fungicidal activity of murine macrophages

Cited by 39 publications

References 46 publications

Effects of Iron on Extracellular and Intracellular Growth of Penicillium marneffei

Effects of Iron on Extracellular and Intracellular Growth of Penicillium marneffei

In Vitro Antifungal-Drug Susceptibilities of Mycelial and Yeast Forms of Penicillium marneffei Isolates in Cambodia

Untitled

Contact Info

Product

Resources

About