Genetic Polymorphism of
            <i>Aspergillus fumigatus</i>
            in Clinical Samples from Patients with Invasive Aspergillosis: Investigation Using Multiple Typing Methods

Bertout, Sébastien; Renaud, François; Barton, Richard; Symoens, Françoise; Burnod, Josette; Piens, M. A.; Lebeau, B.; Viviani, Maria Anna; Chapuis, François; Bastide, J.-M.; Grillot, R.; Mallié, M.

doi:10.1128/jcm.39.5.1731-1737.2001

Cited by 53 publications

(44 citation statements)

References 41 publications

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“…Our result is consistent with earlier studies of more limited scope, for example, no correlation was found between genotype and geography for European and North American individuals (Debeaupuis et al 1997), nor for isolates from French and Italian patients (Bertout et al 2001), nor for environmental and clinical isolates from Canada (Rosehart et al 2002). Neither has any correlation between genotype and geography been found in another, study using a different collection of A. fumigatus individuals and different genetic markers (Rydholm et al 2003).…”

Section: Biogeographysupporting

confidence: 83%

Cryptic Speciation in the Cosmopolitan and Clonal Human Pathogenic Fungus Aspergillus Fumigatus

et al. 2005

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Abstract. Microbes and other organisms smaller than one to a few millimeters in size are hypothesized to have global populations, in contrast to the geographically restricted ranges of larger organisms. However, fungi, which routinely have reproductive propagules no larger than 10 micrometers, challenge the generality of this hypothesis because recent studies have shown that globally distributed morphological species embrace two or more geographically restricted phylogenetic species. We used the concordance of gene genealogies to recognize phylogenetic species in the globally distributed opportunistic human pathogenic fungus, Aspergillus fumigatus. Based on DNA sequence data of five loci for each of 63 individuals collected from five continents, we have delineated two phylogenetic species in this single morphological species. Unlike all other fungi examined to date, both genetically isolated groups showed a global distribution with no evidence of a correlation between genotype and geographic location. Sexual reproduction has never been observed in A. fumigatus, but when the same data were used to explore the association of alleles at the five loci for one of the phylogenetic species, evidence was found to support recombination. The discovery of a cryptic species is medically relevant because different species are likely to differ in virulence or drug resistance. The discovery of a globally distributed A. fumigatus species clade highlights the need for ecological studies of the fungus to either document global dispersal or propose alternative mechanisms by which it persists as single, global phylogenetic population.

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Section: Biogeographysupporting

confidence: 83%

Cryptic Speciation in the Cosmopolitan and Clonal Human Pathogenic Fungus Aspergillus Fumigatus

et al. 2005

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“…Several previous studies have demonstrated that patients with invasive aspergillosis might be infected by more than one strain (7,8,18). Colonization with multiple A. fumigatus genotypes in the CGD patient has also been shown in patients with cystic fibrosis (11,25).…”

Section: Discussionmentioning

confidence: 99%

Molecular Epidemiology of Aspergillus fumigatus Isolates Recovered from Water, Air, and Patients Shows Two Clusters of Genetically Distinct Strains

et al. 2003

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There has been an increase in data suggesting that besides air, hospital water is a potential source of transmission of filamentous fungi, and in particular Aspergillus fumigatus. Molecular characterization of environmental and clinical A. fumigatus isolates, collected prospectively during an 18-month period, was performed to establish if waterborne fungi play a role in the pathogenesis of invasive aspergillosis. Isolates recovered from water (n ‫؍‬ 54) and air (n ‫؍‬ 21) at various locations inside and outside the hospital and from 15 patients (n ‫؍‬ 21) with proven, probable, or possible invasive aspergillosis were genotyped by amplified fragment length polymorphism analysis. Based on genomic fingerprints, the environmental A. fumigatus isolates could be grouped into two major clusters primarily containing isolates recovered from either air or water. The genotypic relatedness between clinical and environmental isolates suggests that patients with invasive aspergillosis can be infected by strains originating from water or from air. In addition, 12 clusters with genetically indistinguishable or highly related strains were differentiated, each containing two to three isolates. In two clusters, clinical isolates recovered from patients matched those recovered from water sources, while in another cluster the clinical isolate was indistinguishable from one cultured from air. This observation might open new perspectives in the development of infection control measures to prevent invasive aspergillosis in high-risk patients. The genetic variability found between airborne and waterborne A. fumigatus strains might prove to be a powerful tool in understanding the transmission of invasive aspergillosis and in outbreak control.With the continuing increase in the number of severely immunocompromised patients, hospitals are faced with the growing problem of invasive aspergillosis and other opportunistic fungal infections (17). Since treatment of these infections is difficult and the outcome is often fatal, preventive measures are of major importance in the control of invasive filamentous fungal infections. Nosocomial invasive aspergillosis is thought to be primarily airborne; however, despite the use of appropriate hospital air filtration systems, the incidence of this infection continues to increase. Together with the lack of genetic relatedness between airborne strains and those causing invasive disease (10, 12), it is tempting to speculate about the existence of other routes of transmission.As early as 1985, Aspergillus species and other filamentous fungi were shown to inhabit water distribution systems that deliver water to hospitals in Europe and the United States (13). Recently, there has been an increase in data supporting water as a potential source of filamentous fungi and, in particular, Aspergillus fumigatus (1, 2, 4, 28). However, direct evidence that waterborne A. fumigatus strains are involved in human infection is lacking. To test the hypothesis that a wet route of transmission might exist, we performed molecu...

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“…Genotypic methods include several techniques, such as random amplified polymorphic DNA (RAPD) analysis (1,10,11), restriction fragment length polymorphism (RFLP) analysis (13), amplified fragment length polymorphism (AFLP) analysis (18), and microsatellite length polymorphism (2). The last technique is sometimes also called microsatellite polymorphism analysis (5) or polymorphic microsatellites marker analysis (8). However, a major problem with pattern-based techniques, such as RAPD, RFLP, and AFLP analyses, is the poor interlaboratory reproducibility.…”

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confidence: 99%

Use of a Novel Panel of Nine Short Tandem Repeats for Exact and High-Resolution Fingerprinting of Aspergillus fumigatus Isolates

et al. 2005

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Here we describe a new panel of short tandem repeats (STRs) for a novel exact typing assay that can be used to discriminate between Aspergillus fumigatus isolates. A total of nine STR markers were selected from available genomic A. fumigatus sequences and were divided into three multicolor multiplex PCRs. Each multiplex reaction amplified three di-, tri-, or tetranucleotide repeats, respectively. All nine STR markers were used to analyze 100 presumably unrelated A. fumigatus isolates. For each marker, between 11 and 37 alleles were found in this population. One isolate proved to be a mixture of at least two different isolates. With the remaining 99 isolates, 96 different fingerprinting profiles were obtained. The Simpson's diversity index for the individual markers ranged from 0.77 to 0.97. The diversity index for the multiplex combination of di-, tri-, and tetranucleotide repeats ranged from 0.9784 to 0.9968. The combination of all nine markers yielded a Simpson's diversity index of 0.9994, indicative of the high discriminatory power of these new loci. In theory, this panel of markers is able to discriminate between no less than 27 ؋ 10 9 different genotypes. The multicolor multiplex approach allows large numbers of markers to be tested in a short period of time. The exact nature of the assay combines high reproducibility with the easy exchange of results and makes it a very suitable tool for large-scale epidemiological studies.

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Genetic Polymorphism of Aspergillus fumigatus in Clinical Samples from Patients with Invasive Aspergillosis: Investigation Using Multiple Typing Methods

Cited by 53 publications

References 41 publications

Cryptic Speciation in the Cosmopolitan and Clonal Human Pathogenic Fungus Aspergillus Fumigatus

Cryptic Speciation in the Cosmopolitan and Clonal Human Pathogenic Fungus Aspergillus Fumigatus

Molecular Epidemiology of Aspergillus fumigatus Isolates Recovered from Water, Air, and Patients Shows Two Clusters of Genetically Distinct Strains

Use of a Novel Panel of Nine Short Tandem Repeats for Exact and High-Resolution Fingerprinting of Aspergillus fumigatus Isolates

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