Osteomyelitis caused by Neosartorya pseudofischeri

Draft Genome Sequence of Azole-Resistant Aspergillus thermomutatus (Neosartorya pseudofischeri) Strain HMR-AF-39, Isolated from a Human Nasal Septum Abscess Aspirate

Here, we present the draft genome sequence of Aspergillus thermomutatus (formerly known as Neosartorya pseudofischeri; strain HMR-AF-39/LSPQ-01276), a cryptic species of Aspergillus section Fumigati. This species is intrinsically resistant to antifungal azoles and is recognized as an agent of invasive aspergillosis among immunocompromised hosts.

Here, we present the draft genome sequence of Aspergillus thermomutatus (formerly known as Neosartorya pseudofischeri; strain HMR-AF-39/LSPQ-01276), a cryptic species of Aspergillus section Fumigati. This species is intrinsically resistant to antifungal azoles and is recognized as an agent of invasive aspergillosis among immunocompromised hosts.

A novel chrysovirus from a clinical isolate of Aspergillus thermomutatus affects sporulation

A clinical isolate of Aspergillus thermomutatus (Teleomorph: Neosartorya pseudofischeri) was found to contain ~35 nm isometric virus-like particles associated with four double-stranded (ds) RNA segments, each of which coded for a single open reading frame. The longest dsRNA element (3589 nt) encodes a putative RNA-dependent RNA polymerase (1114 aa), the second longest dsRNA element (2772 nt) encodes a coat protein (825 aa), and the other two dsRNAs (2676 nt, 2514 nt) encode hypothetical proteins of 768 aa and 711 aa, respectively. Phylogenetic analysis of the amino acid sequences showed 41-60% similarity to the proteins coded by the dsRNAs of the most closely related virus, Penicillium janczewskii chrysovirus 2, indicating that it is a new species based on the International Committee on Taxonomy of Viruses criteria for the genus Chrysovirus. This is the first virus reported from A. thermomutatus and was tentatively named Aspergillus thermomutatus chrysovirus 1. A virus free line of the fungal isolate, cured by cycloheximide treatment, produced large numbers of conidia but no ascospores at both 20°C and 37°C, whereas the virus infected line produced ten-fold fewer conidia at 20°C and a large number of ascospores at both temperatures. The effects of the virus on fungal sporulation have interesting implications for the spread of the fungus and possible use of the virus as a biological control agent.

Causative Agents of Aspergillosis Including Cryptic Aspergillus Species and A. fumigatus

Aspergillosis is an important deep mycosis. The causative agents are Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and Aspergillus terreus, of which A. fumigatus is the most prevalent. Cryptic Aspergillus spp., which morphologically resemble representative species of each Aspergillus section, also cause aspergillosis. Most of the cryptic species reveal different susceptibility patterns and/or different secondary metabolite profiles, also called exometabolome in this manuscript, from those representative species. On the other hand, azole-resistant A. fumigatus strains in clinical specimens and in the environment have been reported. Therefore, it is imperative to precisely identify the species, including cryptic Aspergillus spp., and evaluate the susceptibility of isolates.In this manuscript, some of the causative cryptic Aspergillus spp. are briefly reviewed. In addition, the exometabolome of Aspergillus section Fumigati is described. Finally, azole resistance of A. fumigatus is also discussed, in reference to several studies from Japan.

Rare case of Isolated Aspergillus Osteomyelitis of Toe: Presentation and Management

Introduction:

Fungal osteomyelitis is an uncommon diseases and generally present in an indolent fashion. Isolated bone affection due to fungi are rare and we present one such case with fungal osteomyelitis of terminal phalanx of second toe.

Case Report:

We present a rare case of fungal osteomyelitis of right second toe in a 30 year old Indian female who presented with swelling of 8 months duration. Diagnosis was based on the histo-pathological report and culture showing Aspergillus growth. The patient was treated with surgical debridement and amphotericin-B was given for 6 weeks after debridement. There was no recurrence one year post surgery.

Conclusion:

Isolated Aspergillus osteomyelitis of the bone are very rare and mostly seen in immunocompromised patients and larger bones like spine, femur and tibia. Treatment with wound debridement and subsequently followed up with a course of Amphotericin-B for 6 weeks provided good results. There was no recurrence noted at 1 year follow up. Fungi should be kept in mind for differential diagnosis of osteomyelitis and culture should be appropriately ordered.

Aspergillus fumigatus-Related Species in Clinical Practice

Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA). Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex) may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans, and A. thermomutatus (Neosartorya pseudofischeri) have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF MS) gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

Aspergillus fumigatus and related species

The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field.

Misidentification of Neosartorya pseudofischeri as Aspergillus fumigatus in a lung transplant patient

We present a case of disseminated Neosartorya pseudofischeri infection in a bilateral lung transplant patient with cystic fibrosis. The organism was originally misidentified from respiratory specimens as Aspergillus fumigatus using colonial and microscopic morphology. DNA sequencing subsequently identified the organism correctly as N. pseudofischeri.

Invasive sino-orbital mycosis in an aplastic anemia patient caused by Neosartorya laciniosa

We report the first case of Neosartorya laciniosa invasive sinusitis involving the orbit in an immunocompromised male with aplastic anemia. Treatment included surgical debridement with enucleation of the eye and combination voriconazole and micafungin therapy followed by voriconazole alone. The fungus was identified using sequencing of partial benA and calmodulin genes.

Invasive aspergillosis caused by cryptic Aspergillus species: a report of two consecutive episodes in a patient with leukaemia

We report a case of two consecutive episodes of invasive aspergillosis caused by cryptic Aspergillus species in a patient with leukaemia. A first episode of pulmonary infection was caused by Aspergillus calidoustus and Aspergillus novofumigatus, and the second episode by A. novofumigatus and Aspergillus viridinutans. Fungal isolates were identified to species level using traditional and sequencing-based molecular methods.

Diversity and specificity of microsatellites within Aspergillus section Fumigati

BACKGROUND

Microsatellites (or short tandem repeats, STRs) are the genetic markers of choice for studying Aspergillus fumigatus molecular epidemiology due to its reproducibility and high discrimination power. However, the specificity of these markers must be investigated in a group of isolates from closely related species. The aim of this work was to test a microsatellite-based PCR multiplex previously designed for A. fumigatus in a set of species belonging to section Fumigati, namely Aspergillus fumigatiaffinis, Aspergillus lentulus, Aspergillus novofumigatus, Aspergillus unilateralis, Aspergillus viridinutans, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae.

RESULTS

The reference A. fumigatus strain ATCC 46645 was easily genotyped in standard conditions showing a final electrophoretic profile of 8 expected peaks corresponding to each microsatellite locus. Inversely, no peaks were observed for all other species from section Fumigati, with an exception for marker MC6b in A. unilateralis. By screening the genome sequence of Neosartorya fischeri NRRL 181, the results showed that MC3, MC6a and MC7 might be employed for N. fischeri genotyping since these markers present several repeats of each motif. The accumulation of insertions and deletions was frequently observed in the genomic regions surrounding the microsatellites, including those where the A. fumigatus primers are located. The amplification of microsatellite markers in less stringent amplification conditions resulted in a distinct electrophoretic profile for species within section Fumigati.

CONCLUSIONS

Therefore, the microsatellite-based PCR multiplex allow simple identification of A. fumigatus and, with a slight modification of temperature conditions, it also allows discriminating other pathogenic species within section Fumigati, particularly A. fumigatiaffinis, N. fischeri and N. udagawae.

Aspergillus species identification in the clinical setting

Multiple recent studies have demonstrated the limited utility of morphological methods used singly for species identification of clinically relevant aspergilli. It is being increasingly recognised that comparative sequence based methods used in conjunction with traditional phenotype based methods can offer better resolution of species within this genus. Recognising the growing role of molecular methods in species recognition, the recently convened international working group meeting entitled "Aspergillus Systematics in the Genomic Era" has proposed several recommendations that will be useful in such endeavors. Specific recommendations of this working group include the use of the ITS regions for inter section level identification and the beta-tubulin locus for identification of individual species within the various Aspergillus sections.

Rapid identification of Aspergillus fumigatus within the section Fumigati

Background

New fungal species that are morphologically similar to Aspergillus fumigatus were recently described and included in section Fumigati. Misidentification of such fungal species, particularly of the human pathogens, Aspergillus lentulus, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae, has been increasingly reported by numerous clinical labs. Nevertheless, A. fumigatus still accounts for more than 90% of all invasive aspergillosis cases. The purpose of the present study was to develop a rapid method for the molecular identification of A. fumigatus to distinguish it from other species within the section Fumigati.

Results

A multiplex PCR was developed using prior information based on β-tubulin (βtub) and rodlet A (rodA) partial gene sequences. PCR amplification of βtub and rodA fragments resulted in a distinctive electrophoretic pattern in A. fumigatus and N. udagawae. The polymorphisms found in the smallest amplified sequence of βtub (153 bp) and rodA (103 bp) genes were then compared among and within species of this taxonomic section. βtub was able to differentiate among 13 individual species and two groups of species that included the pathogenic fungus A. lentulus. A more limited number of sequences were available for rodA; nevertheless, we were able to distinguish Aspergillus viridinutans, N. hiratsukae and N. udagawae.

Conclusions

The assay described in the present study proved to be specific and highly reproducible, representing a fast and economic way of targeting molecular identification of the relevant mould, A. fumigatus, in clinical laboratories.

Unusual Aspergillus species in patients with cystic fibrosis

Poorly sporulating Aspergillus isolates from patients with cystic fibrosis (CF) are generally identified in routine procedures as Aspergillus spp. In this study, we identified and characterized 11 isolates belonging to two unusual Aspergillus species of the section Fumigati (A. lentulus and Neosartorya pseudofischeri) recovered from four different patients. Aspergillus lentulus was found occasionally during a 10-year follow-up study of one CF patient colonized by A. fumigatus. Neosartorya pseudofischeri was isolated from three patients followed in different European hospitals. This species was recovered from two sputum samples of one patient, and from four successive samples of the two other patients, suggesting that it may be responsible for chronic colonization. Both species were isolated together with A. fumigatus. Isolates from both species did not grow at 50°C, and DNA sequence analysis, together with further morphological observations permitted identification at the species level. Growth at different temperatures and antifungal susceptibility were also investigated. All the isolates of N. pseudofischeri exhibited a very low susceptibility to voriconazole (VRZ) whereas a very low susceptibility to VRZ and amphotericin B was seen with the A. lentulus isolates.

Re-identification of Aspergillus fumigatus sensu lato based on a new concept of species delimitation

The species concept of Aspergillus fumigatus sensu stricto has recently been defined by polyphasic taxonomy. Based on the new concept of species delimitations, 146 worldwide strains of Aspergillus fumigatus sensu lato were re-identified. Of those 146 strains, 140 (95.8%) could be identified as A. fumigatus sensu stricto, 3 (2.1%) as A. lentulus, and the remaining 3 strains as A. viridinutans complex, Neosartorya udagawae, and N. cf. nishimurae. Of 98 clinical strains, only 1 from dolphin nostril was identified as A. lentulus and not A. fumigatus sensu stricto. Random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR) with primers PELF and URP1F produced nearly the same band patterns among 136 strains of A. fumigatus sensu stricto while discriminated the species from its related species. We also discussed about identification of several atypical A. fumigatus strains from clinical environments.

Invasive aspergillosis due to Neosartorya udagawae

BACKGROUND

Invasive aspergillosis (IA) is most commonly caused by the morphospecies Aspergillus fumigatus. However, genetic-based methods indicate that organisms phenotypically identified as A. fumigatus actually constitute a mold complex, designated Aspergillus section fumigati subgenus fumigati.

METHODS

Multilocus sequencing and analysis was performed on fungi identified as A. fumigatus from the clinical culture collection maintained at the National Institutes of Health from 2000 through 2008, with a focus on the internal transcribed spacer 1 and 2 regions of ribosomal DNA (rDNA), beta-tubulin, and rodlet A genes. We reviewed the medical records, radiology, and histopathology of corresponding patients. To confirm identification of Neosartorya udagawae isolates, mating studies were performed with reference strains. Antifungal susceptibility testing was performed by broth microdilution and read at 48 hours.

RESULTS

Thirty-six cases of infection attributed to A. fumigatus were identified; 4 were caused by N. udagawae (3 in patients with chronic granulomatous disease and 1 in a patient with myelodysplastic syndrome). Disease due to N. udagawae was chronic, with a median duration of 35 weeks, compared with a median duration of 5.5 weeks for patients with chronic granulomatous disease who had infection due to A. fumigatus sensu stricto (P < .05 , Mann-Whitney U test). Infection spread across anatomical planes in a contiguous manner and was refractory to standard therapy. Two of the 4 patients died. N. udagawae demonstrated relatively higher minimum inhibitory concentrations to various agents, compared with those demonstrated by contemporary A. fumigatus sensu stricto isolates.

CONCLUSIONS

To our knowledge, this is the first report documenting infection due to N. udagawae. Clinical manifestations were distinct from those of typical IA. Fumigati-mimetics with inherent potential for antifungal resistance are agents of IA. Genetic identification of molds should be considered for unusual or refractory IA.

Dermatitis caused by Neosartorya hiratsukae infection in a hedgehog

This case report describes the fungal dermatitis caused by Neosartorya hiratsukae infection in a household hedgehog confirmed by microscopic examination of conidiophores and DNA analyses including the internal transcribed spacer region, partial beta-tubulin, and the calmodulin gene. It is the first report of a natural N. hiratsukae infection in animals.

Allergic fungal rhinosinusitis caused by Neosartorya hiratsukae from India

We report here a case of allergic fungal rhinosinusitis caused by Neosartorya hiratsukae. This fungus was never previously been isolated from any case with fungal rhinosinusitis. The identification of this agent was confirmed by comparing the nucleotide sequence of the ITS region of ribosomal DNA with that in the GenBank DNA database. Identification of N. hiratsukae on the basis of colony morphology and microscopic feature may be difficult due to similarities with a few Aspergillus species. Scanning electron microscopy or DNA sequence analysis is essential for the accurate identification.

Effect of ostreolysin, an Asp-hemolysin isoform, on human chondrocytes and osteoblasts, and possible role of Asp-hemolysin in pathogenesis

Aspergillus fumigatus, a pathogenic mould causing a wide range of diseases including aspergillosis, produces a series of toxic substances which appear to act in an additive and/or synergic way on cells. Aspergillosis generally occurs in immunocompromised hosts or is associated with organ transplantation. From the muscul skeleton system the vertebrae, ribs and orbit are the most commonly affected, while the joints are less frequent targets. The cytolytic protein Asp-hemolysin is one of the toxins produced by Aspergillus fumigatus during infection. It belongs to the aegerolysin protein family and shares 43% identity in amino acid sequence with ostreolysin, a cytolysin from the mushroom Pleurotus ostreatus. In this work, ostreolysin was used in an experimental model to study the in vitro effects of aegerolysin-like proteins on human chondrocytes and osteoblasts. Immunostaining analyses showed selective binding and clustering of the protein on chondrocyte membranes, pointing to its association with distinctive membrane microdomains. Consequently, ostreolysin can induce effective permeabilization of both chondrocytes and osteoblasts. Based on sequence similarities of ostreolysin and Asp-hemolysin, their comparable cytolytic effects towards different cells, and similar signs of intoxication in experimental animals, our results indicate that Asp-hemolysin might be considered as a possible virulence factor of Aspergillus fumigatus during the infection of bone and cartilage.

Polyphasic taxonomy of Aspergillus section Fumigati and its teleomorph Neosartorya

The taxonomy of Aspergillus section Fumigati with its teleomorph genus Neosartorya is revised. The species concept is based on phenotypic (morphology and extrolite profiles) and molecular (beta-tubulin and calmodulin gene sequences) characters in a polyphasic approach. Four new taxa are proposed: N. australensis N. ferenczii, N. papuaensis and N. warcupii. All newly described and accepted species are illustrated. The section consists of 33 taxa: 10 strictly anamorphic Aspergillus species and 23 Neosartorya species. Four other Neosartorya species described previously were not available for this monograph, and consequently are relegated to the category of doubtful species.

Mistaken identity: Neosartorya pseudofischeri and its anamorph masquerading as Aspergillus fumigatus

Invasive fungal infections caused by Neosartorya pseudofischeri S. W. Peterson [anamorph Aspergillus thermomutatus (Paden) S. W. Peterson] are extremely rare. Phenotypically, the anamorphic state of N. pseudofischeri resembles Aspergillus fumigatus, the predominant agent of invasive aspergillosis in immunocompromised hosts. We report the recovery of three clinical isolates of N. pseudofischeri, all initially misidentified by morphological characteristics as A. fumigatus. All three isolates were correctly identified by sequencing portions of the beta-tubulin and the rodlet A genes. Only one of the three isolates produced the confirmatory fruiting bodies and was thus classified as N. pseudofischeri; the other isolates did not produce asci and were therefore identified as A. thermomutatus. All three isolates had higher MICs to voriconazole in vitro compared to A. fumigatus Af293. This report emphasizes that phenotypic identification of filamentous fungi may not identify morphologically similar, but genetically distinct, members of the genus Aspergillus section Fumigati. Accurate identification of these organisms may be clinically meaningful, given their potential differences in antifungal susceptibilities.

New resistance mechanisms to azole drugs in Aspergillus fumigatus and emergence of antifungal drugs-resistant A. fumigatus atypical strains

Azole drug resistance in Aspergillus fumigatus is an uncommon but well-known phenomenon. The analysis of resistance mechanisms at molecular level has identified the bases for A. fumigatus azole resistance. To date, the most prevalent mechanism of azole resistance appears to be the modification of Cyp51, specifically mutations in cyp51A gene. These mutations have been associated with three different antifungal susceptibility profiles: (i) cross-resistance to itraconazole and posaconazole that has been associated with amino acid substitutions at glycine 54 (G54), (ii) elevated MICs to all azole drugs associated with amino acid substitutions at methionine M220, and (iii) cross-resistance to all azole drugs related to the presence of Cyp51A substitutions at leucine 98 for histidine (L98H) linked to a duplication in tandem of a 34 bp repeat in the cyp51A promoter region, which seem to be responsible for increased cyp51A gene expression. Another matter of concern is the increasing reports of isolation of genetic variants of A. fumigatus, originally misidentified as poorly sporulating strains of A. fumigauts, as a causative agents of invasive infection. Many of these isolates belonging to the Aspergillus section Fumigati have been found to be resistant in vitro to multiple antifungal drugs. Current data show that susceptibility profile of these variants could be predictable depending on the species. Resistance among clinical strains of filamentous fungi may become more common in the future associated with the spread of prophylaxis, pre-emptive treatments and specific therapies with antifungal agents.

Molecular typing of aspergilli: Recent developments and outcomes

Aspergillus spp. have been the subject of numerous epidemiological studies. The most useful typing techniques are DNA based methods including the random amplified polymorphic DNA technique, microsatellite length polymorphisms, restriction fragment length polymorphism (RFLP) analysis using retrotransposon-like sequences as probes, and multilocus sequence typing. The results of typing clinical isolates indicate that most of the invasive aspergillosis (IA) patients were infected by a single strain. Genetic analysis could not discriminate between clinical and environmental isolates of Aspergillus. fumigatus, indicating that every strain present in the environment is a potential pathogen if it encounters the appropriate host. The source of infection can also be monitored by typing. Typing studies led to the discovery of a new pathogenic species, A. lentulus, and to the identification of several species not known previously to be pathogenic. Typing studies revealed the existence of two genetically isolated groups within a global A. fumigatus population. Aspergillus fumigatus was found to be the first example of a true cosmopolitan fungus. Additionally, the results obtained in several studies support the premise that recombination played an important role in A. fumigatus populations. The discovery of functional mating type genes in A. fumigatus indicates that past or recent sexual processes could be responsible for the observed recombining population structure.

The invasive and saprophytic syndromes due to Aspergillus spp

Aspergillus spp. produce a wide range of invasive and sapropytic syndromes which may involve any tissue. Within a given tissue or organ the pathology and pathogenesis varies enormously, ranging from angioinvasive disease to noninvasive saprophytic disease. The individual invasive and saprophytic syndromes in which a causative role can be attributed to Aspergillus spp. are detailed specifically with reference to the underlying pathology and pathogenesis, the clinical setting and features, and the manner in which a diagnosis can be established.

Isolation of Neosartorya pseudofischeri from blood: first hint of pulmonary Aspergillosis

We report a case of invasive pulmonary aspergillosis caused by Neosartorya pseudofischeri S. W. Peterson [anamorph Aspergillus thermomutatus (Paden) S. W. Peterson]. The diagnosis was initially based on a positive blood culture for a strain isolated from a neutropenic patient by means of a BACTEC 9050 blood culture system. The final diagnosis was established based on X-ray and computer tomography scan results as well as the detection of Aspergillus antigen in the patient's serum.

Cerebral aspergillosis caused by Neosartorya hiratsukae, Brazil

We report the first case of infection by Neosartorya hiratsukae, an ascomycete in which the conidial state resembles Aspergillus fumigatus. The fungus caused a brain infection in a Brazilian woman, who died despite itraconazole treatment. Diagnosis was established by direct microscopic examination, computed tomographic scan, and magnetic resonance imaging of the brain, and repeated cultures from the lesions. The in vitro antifungal susceptibility of the isolate is provided.

Mitochondrial cytochrome b gene analysis of Aspergillus fumigatus and related species

Nucleotide sequences of 426 bp from the mitochondrial (mt) cytochrome b genes of six anamorph species and two species of Neosartorya teleomophs of Aspergillus section Fumigati were determined. These sequences were used to build nucleotide- and amino acid-based trees for phylogenetic analysis. Thirteen strains of A. fumigatus including 10 clinical isolates of A. fumigatus, 1 type culture of A. fumigatus var. fumigatus, 1 type culture of A. fumigatus var. ellipticus, and 1 strain of A. fumigatus var. albus, had the same nucleotide sequences. One strain of A. fumisynnematus, two strains labeled A. neoellipticus, two strains of A. viridinutans, and one strain of A. duricaulis had distinct nucleotide and amino acid sequences. Two strains of A. brevipes were divided into two types. One produced a 1,500-bp fragment that included an intron. The nucleotide sequences of its two exons were similar to those of the A. fumigatus, and the derived amino acid sequence was the same as that for A. fumigatus. The other produced a 426-bp fragment and had the same nucleotide and amino acid sequences as A. unilateralis. Neosartorya fischeri var. fischeri and N. stramenia had nucleotide sequences that differed from that of A. fumigatus. These species possessed their own characteristic nucleotide sequences that differed from each other. In comparisons of homologous sequences from four other pathogenic species of Aspergillus, regions specific to section Fumigati were found. The mt cytochrome b gene analysis was valuable for the identification, classification, and phylogenetic analysis of isolates of section Fumigati.

Femur osteomyelitis due to a mixed fungal infection in a previously healthy man

We describe a previously healthy, 22-year-old man who, after a closed fracture of the femur and subsequent operation, developed chronic osteomyelitis. Within a few days, infected bone fragments, bone, and wound drainage repeatedly yielded three different filamentous fungi: Aspergillus fumigatus, Aspergillus flavus, and Chalara ellisii. Histologic examination of the bone revealed septate hyphae. After sequential necrotomies of the femur and irrigation-suction drainage with added antimycotic therapy, the infection ceased and the fracture healed. This case is unique in that it is the only known instance in which a long bone was affected in an immunocompetent individual, with no evidence of any systemic infection, by a mixed population of two different Aspergillus spp. and the rare filamentous fungus C. ellisii. Environmental factors that could potentiate the infection include blood and edema fluid resulting from the surgical procedure and the presence of the osteosynthetic plate.

A comparative study of the broth micro- and macro-dilution techniques for the determination of the in vitro susceptibility of Aspergillus fumigatus

The effects of inoculum size, medium, temperature, and duration of growth on the in vitro susceptibility testing of Aspergillus fumigatus were investigated using broth micro- and macro-dilution techniques. The minimum inhibitory concentrations (MICs) of ketoconazole, miconazole, itraconazole, fluconazole, and amphotericin B were significantly influenced by the inoculum size, regardless of the techniques used. Two- to four-fold higher MIC values were obtained when the inoculum size was increased 100-fold. The use of peptone yeast extract glucose and RPMI 1640 media provided essentially identical MIC values at 30 and 35 degrees C after incubation for 48 h or longer. A comparison of broth micro- and macro-dilution techniques revealed that, under equivalent conditions, the latter with an inoculum size between 1 x 10(3) and 1 x 10(4) conidia (strain W73355)/mL consistently provided the lowest MICs of fluconazole (256 micrograms/mL), ketoconazole (8 micrograms/mL), miconazole (2 micrograms/mL), itraconazole (0.25 micrograms/mL), and amphotericin B (0.25 micrograms/mL). Using the broth macrodilution technique we screened 24 clinical isolates of A. fumigatus obtained from the Detroit Medical Center in 1994. The MIC values of fluconazole, ketoconazole, miconazole, itraconazole and amphotericin B for all the isolates were 128-256, 8-16, 1-2, 0.25-0.5, and 0.25-1.0 micrograms/mL, respectively, indicating that none of the clinical isolates that we tested shows acquired resistance to the antifungals used.