Atypical Cytomorphologic Appearance of &lt;i&gt;Cryptococcus neoformans&lt;/i&gt;

Williamson, John D.; Silverman, Jan F.; Mallak, Craig T.; Christie, John D.

doi:10.1159/000333769

Cited by 37 publications

(28 citation statements)

References 9 publications

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“…Fine needle aspiration 22 Isolation of any type of fungus on culture of fine needle aspirates Isolation of Candida species on surgical drain fluid culture t-test; discrete variables were compared using Z-test for proportions. All tests were two-tailed; a p-value less than or equal to 0.05 was considered statistically significant.…”

Section: Discussionmentioning

confidence: 99%

Epidemiology of fungal infections in critical care setting of a tertiary care teaching hospital in North India: a prospective surveillance study

Singh¹,

Kashyap²,

Ahluwalia³

et al. 2014

JCSR

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Background: During recent years, fungal infections have risen exponentially and are a cause of significant morbidity and mortality in hospitalized patients, especially in the critical care setting. There is paucity of data from India on fungal pathogens. Methods:We prospectively studied patients admitted to medical and surgical critical care section of a tertiary care institute in northern India. The clinical samples of patients were processed in Department of Microbiology for isolation and identification of fungi by using standard protocols over a period of one year. The patients were categorized into fungal infection and colonization groups. The demographic data and risk factors for fungal infection and colonization were evaluated.Results: Ninety one (82.7%) of the 110 patients enrolled in the study, had fungal infection, whereas 19 (17.3%) had fungal colonization. Candida were isolated from 85/91 (93.4%) and 19/19 (100%) patients with fungal infection and colonization respectively. There was predominance of non-albicans Candida spp both in fungal infection 61/85 (71.7%) patients as well as fungal colonization group 16/19 (84.2% ). In non-albicans Candida spp., Candida tropicalis was the most common isolate observed in both fungal infection (85.3%) and fungal colonization (63.1%) groups. Overall, in patients with fungal infection, candiduria was detected in 68/91 (74.7%) whereas candidaemia was observed in 19/ 91 (20.8%) patients. The risk factors for fungal infections included urinary catheterization (85.7%), central line insertion (81.3%), mechanical ventilation (52.7%), use of corticosteroids (23.1%), total parentral nutrition (6.6%) and peritoneal dialysis (3.3%). Conclusions:The emergence of non-albicans Candida similar to the trends in the western countries should be a cause of concern in our country. Proper surveillance of fungal pathogens is important to improve quality of care in critical care setting and measures should be focussed to control these infections, especially in patients with these risk factors.

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Section: Discussionmentioning

confidence: 99%

Epidemiology of fungal infections in critical care setting of a tertiary care teaching hospital in North India: a prospective surveillance study

Singh¹,

Kashyap²,

Ahluwalia³

et al. 2014

JCSR

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“…Research on different morphological forms has implicated positive roles for cell gigantism in disease (11)(12)(13)(14)(15)(16) and negative roles for filaments in disease and conversely inducing a protective response from the host (17)(18)(19)(20)(21)(22). Accordingly, the filamentous form is only occasionally observed in host tissues and is considered an atypical form for Cryptococcus in vivo (5)(6)(7)(8)(9)(10). The association between morphogenesis and virulence in Cryptococcus is thus similar to that observed in other conventional dimorphic fungal pathogens, such as Histoplasma capsulatum and Blastomyces dermatitidis (23)(24)(25)(26).…”

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confidence: 82%

Congenic Strains of the Filamentous Form of Cryptococcus neoformans for Studies of Fungal Morphogenesis and Virulence

et al. 2013

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cCryptococcus neoformans is an unconventional dimorphic fungus that can grow either as a yeast or in a filamentous form. To facilitate investigation of genetic factors important for its morphogenesis and pathogenicity, congenic a and ␣ strains for a filamentous form were constructed. XL280 (␣) was selected as the background strain because of its robust ability to undergo the morphological transition from yeast to the filamentous form. The MATa allele from a sequenced strain JEC20 was introgressed into the XL280 background to generate the congenic a and ␣ pair strains. The resulting congenic strains were then used to test the impact of mating type on virulence. In both the inhalation and the intravenous infection models of murine cryptococcosis, the congenic a and ␣ strains displayed comparable levels of high virulence. The a-␣ coinfections displayed equivalent virulence to the individual a or ␣ infections in both animal models. Further analyses of the mating type distribution in a-␣ coinfected mice suggested no influence of a-␣ interactions on cryptococcal neurotropism, irrespective of the route of inoculation. Furthermore, deletion or overexpression of a known transcription factor, Znf2, in XL280 abolished or enhanced filamentation and biofilm formation, consistent with its established role. Overexpression of Znf2 in XL280 led to attenuation of virulence and a reduced abundance in the brain but not in other organs, suggesting that Znf2 might interfere with cryptococcal neurotropism upon extrapulmonary dissemination. In summary, the congenic strains provide a new resource for the exploration of the relationship in Cryptococcus between cellular morphology and pathogenesis.

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“…(40) Uncommon forms, which include pseudohyphae, germ tube-like structures and chains of budding yeasts, are easily identified by the GMS technique. (9,40,49) Chapter 3 -Pulmonary cryptococcosis inflammatory response of the host, for prognosis and for biological activity, demonstrating that the granulomatous response is associated with the control of infection.…”

Section: Histopathological Examinationmentioning

confidence: 99%

“…are observed with or without budding; they are also observed as multi-budding, poorly-encapsulated or capsule-deficient fungal elements or as pseudohyphae. (6)(7)(8)(9) In the environment, C. neoformans is found in association with pigeon excreta and in tree hollows worldwide. For years, C. gattii was found only in tropical and subtropical regions.…”

Section: Introductionmentioning

confidence: 99%

Capítulo 3: criptococose pulmonar

Severo

Gazzoni²,

Severo

2009

J. bras. pneumol.

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on the agglutination reactions of capsular polysaccharide antigens. Serotype A and serotype D strains, as well as the AD hybrid, are classified as C. neoformans, whereas serotype B and serotype C strains have been classified as C. gattii. Serotype A strains have been designated C. neoformans var. grubii, whereas serotype D strains have been designated C. neoformans var. neoformans.(3) This classification was based on the differences in capsular structure and DNA between the strains, as well as on a complete comparison of the genomic sequencing of these two serotypes (strains).(3) In addition, based on new molecular data and on evolutionary studies, IntroductionCryptococcosis is an infection caused by the naturally encapsulated basidiomycete of the genus Cryptococcus, which has recently become the most relevant opportunistic fungal pathogen.(1) The infection caused by the species C. neoformans has become the most critically relevant opportunistic infection as a consequence of the AIDS epidemic. In addition, C. gattii recently caused an isolated cryptococcosis outbreak among apparently immunocompetent humans and animals on Vancouver Island, Canada. AbstractCryptococcosis is a systemic mycosis caused by two species of the encapsulated basidiomycetes, Cryptococcus neoformans and C. gattii, which, respectively, cause infection in immunocompromised individuals and in immunologically normal hosts. Patients with T-cell deficiencies are more susceptible to this infection. The spectrum of the disease ranges from asymptomatic pulmonary lesions to disseminated infection with meningoencephalitis. The medical relevance of cryptococcosis increased dramatically as a consequence of the AIDS epidemic and organ transplants.Keywords: Cryptococcus neoformans; Pneumonia; Acquired immunodeficiency syndrome; Amphotericin B; Fluconazole. ResumoCriptococose é uma micose sistêmica causada por duas espécies do basidiomiceto encapsulado, Cryptococcus neoformans e C. gattii, que, respectivamente, causam infecção em indivíduos imunocomprometidos e em hospedeiros imunocompetentes, respectivamente. Pacientes com deficiência em células T são mais suscetíveis. A infecção se inicia por lesões pulmonares assintomáticas e a doença disseminada frequentemente cursa com meningoencefalite. A importância médica da criptococose aumentou significativamente em consequência da epidemia da AIDS e dos transplantes de órgãos.

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Atypical Cytomorphologic Appearance of <i>Cryptococcus neoformans</i>

Cited by 37 publications

References 9 publications

Epidemiology of fungal infections in critical care setting of a tertiary care teaching hospital in North India: a prospective surveillance study

Epidemiology of fungal infections in critical care setting of a tertiary care teaching hospital in North India: a prospective surveillance study

Congenic Strains of the Filamentous Form of Cryptococcus neoformans for Studies of Fungal Morphogenesis and Virulence

Capítulo 3: criptococose pulmonar

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