Dynamics of fungal colonization in a new medical mycology laboratory

Sautour, Marc; Fournel, Isabelle; Dalle, Frédéric; Calinon, Céline; l'Ollivier, Coralie; Goyer, Marianne; Cachia, Claire; Aho, Serge; Sixt, Nathalie; Vagner, O.; Cuisenier, B.; Bonnin, Alain

doi:10.1016/j.mycmed.2011.11.001

Cited by 7 publications

(4 citation statements)

References 22 publications

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“…Various studies have shown high contamination rates and low fungal culture yield, despite using special mediums like Sabouraud dextrose agar supplemented with chloramphenicol and cycloheximide. 14,24 Similar findings of high contamination rate (6%) and low dermatophyte culture yield (40%) was observed in our study, for the samples processed as per standard procedures (Protocol A).…”

Section: Discussionsupporting

confidence: 87%

Effects of different sample processing protocols on dermatophyte culture yield: A comparative study

Gill¹,

Sen²,

Agarwal³

2020

IJMR

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Introduction: Dermatophytes fungi infect keratinized tissues such as hair, nails and skin. Different methods for sample collection and transportation of dermatophytes for culture have been described. The standard methods for dermatophytes sample collection, transportation and lab processing, results in low positive culture dermatophyte yield. In this study, we have compared the standard method (Protocol A) with modified sample processing protocol (Protocol B), developed by our department. This modification was based on the core concept of collection, inoculation, starting incubation and transportation of dermatophyte sample, at patient's point of care. Materials and Methods: A total of 200 clinical isolates of dermatophytes, were subjected to two different sample processing protocols. Standard method was Protocol A and laboratory developed method was labelled as Protocol B. Protocol B, included a small (7ml) transparent plastic tube with special culture media. These tubes were inoculated with sample at patient's point of care and same tube were utilized as transportation media. Results: Samples processed as per modified protocol (Protocol B), demonstrated positive dermatophyte culture yield in 160 out of 200 samples, whereas figures were 80 out of 200 for samples processed as per standard protocol (Protocol A). Difference in positive dermatophyte culture yields, were statistically significant. The contamination rates of dermatophyte culture by saprophytic fungus and bacteria, was measured, 6% for Protocol A and 1% for Protocol B. Conclusion:Our study demonstrated that a simple, economical modification in the procedure for dermatophyte sample processing by the laboratory, has led to a significant increase the positive dermatophyte culture yield with reduced secondary contamination rates.

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Section: Discussionsupporting

confidence: 87%

Effects of different sample processing protocols on dermatophyte culture yield: A comparative study

Gill¹,

Sen²,

Agarwal³

2020

IJMR

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“…have also been described as components of human oral and gut microbiota . The conidia become easily aerosolized; this explains their role as environmental contaminants . Historically, non‐ marneffei species rarely cause disease in humans and are encountered most commonly in the clinical laboratory as culture contaminants; however, recently they have emerged as opportunistic pathogens in immunocompromised hosts.…”

Section: Introductionmentioning

confidence: 99%

Successful treatment of pulmonary invasive fungal infection by Penicillium non‐marneffei in lymphoblastic lymphoma: case report and literature review

Ramírez

Hidrón

Cardona

2018

Clinical Case Reports

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“…rubens (strain CBS 401.92; CBS Fungal Biodiversity Centre, Utrecht, The Netherlands) was isolated from a large-scale survey of the fungal flora on affected indoor surfaces in social housing in The Netherlands in 1991, in which it appeared to be a predominant species (2). In many other studies (5,28,47,48,49), P. rubens is reported to be a common indoor species in both surface and air sampling. The strain used in this study was formerly known as P. chrysogenum (34) ; Acros) was added.…”

Section: Methodsmentioning

confidence: 99%

Production of an Extracellular Matrix as an Isotropic Growth Phase of Penicillium rubens on Gypsum

Bekker

Huinink

Adan

et al. 2012

Appl Environ Microbiol

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cIndoor mold represents an important environmental concern, but a fundamental knowledge of fungal growth stages is needed to limit indoor fungal proliferation on finishing materials used in buildings. The present study focused on the succession of germination stages of the common indoor fungus Penicillium rubens on a gypsum substrate. This substrate is used as a model system representing porous materials that are widely used in indoor environments. Imaging with cryo-scanning electron microscopy showed that the formation of an extracellular matrix (ECM) is a phase of the isotropic growth of P. rubens that is uniquely related to germinating conidia. Furthermore, the ECM is observed only when a dry-state inoculation of the surface is applied, i.e., applying conidia directly from a 7-day-old colony, mimicking airborne contamination of the surface. When inoculation is done by spraying an aqueous conidial suspension, no ECM is observed. Moreover, it is concluded that the formation of an ECM requires active processes in the fungal cell. The porosity of the substrate proved that the ECM substance has high-viscosity characteristics. The present results stress that studies of indoor fungal growth should consider the method of inoculation, knowing that the common aqueous suspension may obscure specific stages in the initial phases of germination. Indoor mold and moisture and their associated health effects are widespread and important societal problems (11,27). Without doubt, mold growth requires the presence of water. Water can occur in different forms and may originate from different sources in the indoor environment, i.e., as water vapor in the indoor airair humidity-or in liquid form in the pore system of a material, originating from external sources such as rain, melting snow, rising dampness, or accidental leakage.Detailed understanding of the fungal growth phases and the interaction of a substrate, water, and fungi provides information to identify the weakest link in fungal growth. Such knowledge lays the foundation for effective intervention or prevention strategies. The availability of water can be expressed in many ways. Common parameters are water activity (a w ), which is widely used in microbiology to describe the water in substrates, and relative humidity (RH), which is typically used to describe water vapor in air. In equilibrium, the two quantities are directly related (26,39).Indoor fungi can be grouped according to their water tolerance. Magan and Lacey (38) distinguished hydrophilic (waterloving) and xerophilic (dry-loving) species on the basis of the minimum water activity required for growth. This scheme has been widely accepted and is based on a 0.9 a w or 90% RH threshold value.It is known that a w or RH influences each of the main phases of the growth cycle. In studies of Aspergillus and Penicillium species (1, 7, 41) on culture media, the minimum value of the a w for germination was lower than that for linear growth, which in turn was usually lower than that for asexual sporulation.Many studies hav...

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Dynamics of fungal colonization in a new medical mycology laboratory

Cited by 7 publications

References 22 publications

Effects of different sample processing protocols on dermatophyte culture yield: A comparative study

Effects of different sample processing protocols on dermatophyte culture yield: A comparative study

Successful treatment of pulmonary invasive fungal infection by Penicillium non‐marneffei in lymphoblastic lymphoma: case report and literature review

Production of an Extracellular Matrix as an Isotropic Growth Phase of Penicillium rubens on Gypsum

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