Isolation of <Emphasis Type="Italic">Penicillium marneffei</Emphasis> From Soil and Wild Rodents in Guangdong,SE China

Infection by Penicillium marneffei is an important emerging public health problem, especially among travelers and inhabitants in SE China and SE Asia infected with human immunodeficiency virus (HIV). In recent years, the number of patients with penicilliosis marneffei (PM) has increased rapidly in Guangdong province, SE China. However, the natural habitat and transmission mode of the etiologic agent remains unclear. In this study, wild rats (Microtus, focus Rattus and Rhizomys pruinosus) and soil samples were collected from rat burrows, populated and rural areas from November 2007 to December 2008 for fungus cultures. All isolates, suspected of being P. marneffei, were identified by gross and microscopic morphology and ITS analysis. Sixteen of 23 (about 70%) bamboo rats were P. marneffei positive, whereas none was recovered from hamsters, loirs or soil. This suggests that as of today the bamboo rat is the exclusive natural reservoir for P. marneffei. Definite evidence that rodents are a part of the infectious cycle is still lacking.     

Penicillium Marneffei N. Sp., Agent D'une Mycose Du Système Réticulo-Endothélial

Résumé 1) Une espèce nouvelle dePenicillium, P. marneffei,Segretain, Capponi, Sureau, a été isolée d'un rongeur du Centre Viet Nam,Rhizomys sinensis ou rat de bambou, provoquant la mortalité de cet animal en captivité,2) Ce champignon est expérimentalement pathogène pour la souris le hamster et le rat, atteints d'une réticulose macrophagique semblable à l'histoplasmose ou à la leishmaniose.3) Le champignon se développe dans les cellules réticulaires où il se présente sous forme ronde, ovale ou légèrement allongée. Il se multiplie par cloisonnement transversal.4)En culture à 37°,P. marneffei donne des cultures glabres, lisses ou plissées, de consistance crémeuse, ressemblant à une culture bactérienne et formées d'arthrospores.5)Par ses caractères botaniques, le champignon doit être considéré comme une espèce nouvelle, à rapprocher deP. janthinellum et deP.citrinum.

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Summary 1) A new species ofPenicillium, P. marneffei Segretain, Capponi, Sureau, has been isolated from a rodent of the center of Viet Nam,Rhizomys sinensis or bamboo rat; it causes the death of this animal living in captivity.2) This fungus is experimentally pathogen for mice, hamsters and rats: it produces a reticulosis similar to histoplasmosis or leishmaniosis.3) The fungus grows in the reticulo-endothelial cells in which its form is round, oval or slightly elongated. It multiplies by scissiparity.4) At 37° C the colony ofP. marneffei is glabrous, smooth or folded, resembling that of Bacteria and formed by arthrospores.5) By its botanical caracters, the fungus is considered as a new species to be classed nearP. janthinellum andP. citrinum.

     

Clonality Despite Sex: The Evolution of Host-Associated Sexual Neighborhoods in the Pathogenic Fungus Penicillium marneffei

Molecular genetic approaches typically detect recombination in microbes regardless of assumed asexuality. However, genetic data have shown the AIDS-associated pathogen Penicillium marneffei to have extensive spatial genetic structure at local and regional scales, and although there has been some genetic evidence that a sexual cycle is possible, this haploid fungus is thought to be genetically, as well as morphologically, asexual in nature because of its highly clonal population structure. Here we use comparative genomics, experimental mixed-genotype infections, and population genetic data to elucidate the role of recombination in natural populations of P. marneffei. Genome wide comparisons reveal that all the genes required for meiosis are present in P. marneffei, mating type genes are arranged in a similar manner to that found in other heterothallic fungi, and there is evidence of a putatively meiosis-specific mutational process. Experiments suggest that recombination between isolates of compatible mating types may occur during mammal infection. Population genetic data from 34 isolates from bamboo rats in India, Thailand and Vietnam, and 273 isolates from humans in China, India, Thailand, and Vietnam show that recombination is most likely to occur across spatially and genetically limited distances in natural populations resulting in highly clonal population structure yet sexually reproducing populations. Predicted distributions of three different spatial genetic clusters within P. marneffei overlap with three different bamboo rat host distributions suggesting that recombination within hosts may act to maintain population barriers within P. marneffei.     

Identification of <Emphasis Type="Italic">Penicillium marneffei</Emphasis> in Paraffin-Embedded Tissue Using Nested PCR

Penicillium marneffei is one of the unique thermally dimorphic fungi in Penicillium species that causes a disseminated, progressive and life threatening infection in immunocompromised patients. The diagnosis of Penicilliosis marneffei depends on culture that may delay the treatment due to the time-consuming process. In the present study, we evaluated the specificity and sensitivity of nested PCR to identify Penicillium marneffei from paraffin-embedded tissue. Two sets of oligonucleotide primers were derived from the sequence of 18S rRNA of Penicillium marneffei. The outer primers (RRF1 and RRH1) were specific to fungi. The inner primers (Pm1 and Pm2) were specific to Penicillium marneffei. The specific fragment of approximately 400 bp was amplified from all paraffin-embedded tissues from 14 patients with Penicilliosis marneffei and 10 bamboo rats. The detectable DNA concentration of single PCR and nested PCR were 14 pg/μl and 14 fg/μl, respectively. Further studies are required in order to use nested PCR for early diagnosis of the disease.     

Dynamic expression of a cell-surface determinant ofCandida albicans

Penicilliosis marneffei has emerged as an endemic systemic mycosis in Southeast Asia among humans and wild bamboo rats. To gain an insight into the epidemiology of this life-threatening disease, a survey of bamboo rats for natural infections byPenicillium marneffei was carried out in the central plains of Thailand during June-September, 1987. Thirty-one lesser bamboo rats (Cannomys badius) and eight hoary bamboo rats (Rhizomys pruinosus) were trapped. Portions of their internal organs were cultured to determine if they had been infected byP. marneffei. Six each ofC. badius (19.4%) andR. pruinosus (75%) yielded cultures of this unique, dimorphicPenicillium species. All of the isolates were readily converted to their unicellular form that multiplies by the process of schizogony by incubating them at 37 °C on plates of brain heart infusion agar. Their identity was further confirmed by a specific immunological test. Among the internal organs of the positive rats, the lungs had the highest positivity (83.3%), next in decreased order of frequency were the liver (33.3%) and the pancreas (33.3%). The use and value of domestic and wild animals in locating and demarcating endemic areas of geophilic fungal pathogens are discussed. Penicilliosis marneffei is considered to be a zooanthroponosis — a disease that occurs in lower animals, as well as, humans.     

Rapid identification and characterization of Penicillium marneffei using multiplex ligation-dependent probe amplification (MLPA) in paraffin-embedded tissue samples

Penicillium marneffei infection is a deadly disease and early diagnosis leads to prompt and appropriate antifungal therapy. To develop a sensitive method to diagnose P. marneffei infection, a multiplex ligation-dependent probe amplification (MLPA) assay was adapted. This method can rapidly and specifically detect P. marneffei DNA in cultured cells and paraffin-embedded tissue samples. Three pairs of probes were designed for amplifying the internally (intergenic) transcribed spacer (ITS) region of P. marneffei rRNA using a systematic phylogenetic analysis. These three probe sets produced three amplicons of 198, 166, and 152 bp, respectively, specific for P. marneffei. In contrast, there was only one 198 bp amplicon produced for Talaromyces stipitatus, and one 152 bp amplicon for P. funiculosum, T. intermedius and T. derxii. The probes did not amplify any other reference strains. An array of 40 P. marneffei strains isolated from human patients, bamboo rat, and the local environment was tested by using MLPA, and all were positively identified. Most importantly, P. marneffei in paraffin-embedded tissue specimens from infected human patients was positively amplified by MLPA. The sensitivity and specificity of the MLPA assay could be a useful tool for prompt diagnosis, pathogen characterization, and epidemiological studies of fungal infections.     

Transmission of Pepino mosaic virus by the Fungal Vector Olpidium virulentus

Transmission of Pepino mosaic virus (PepMV) by the fungal vector Olpidium virulentus was studied in two experiments. Two characterized cultures of the fungus were used as stock cultures for the assay: culture A was from lettuce roots collected in Castellón (Spain), and culture B was from tomato roots collected in Murcia (Spain). These fungal cultures were maintained in their original host and irrigated with sterile water. The drainage water collected from irrigating these stock cultures was used for watering PepMV‐infected and non‐infected tomato plants to constitute the acquisition–source plants of the assay, which were divided into six different plots: plants containing fungal culture A (non‐infected and PepMV‐infected); plants containing fungal culture B (non‐infected and PepMV‐infected); PepMV‐infected plants without the fungus; and plants non‐infected either with PepMV and the fungus. Thirty‐six healthy plants grouped into six plots, which constituted the virus acquisition–transmission plants of the assay, were irrigated with different drainage waters obtained by watering the different plots of the acquisition–source plants. PepMV was only transmitted to plants irrigated with the drainage water collected from PepMV‐infected plants whose roots contained the fungal culture B from tomato with a transmission rate of 8%. No infection was detected in plants irrigated with the drainage water collected from plots with only a fungus or virus infection. Both the virus and fungus were detected in water samples collected from the drainage water of the acquisition–source plants of the assay. These transmission assays demonstrated the possibility of PepMV transmission by O. virulentus collected from tomato crops.     

Differentially regulated high‐affinity iron assimilation systems support growth of the various cell types in the dimorphic pathogen Talaromyces marneffei

Iron is a key trace element important for many biochemical processes and its availability varies with the environment. For human pathogenic fungi iron acquisition can be particularly problematical because host cells sequester free iron as part of the acute‐phase response to infection. Fungi rely on high‐affinity iron uptake systems, such as reductive iron assimilation (RIA) and siderophore‐mediated iron uptake (non‐RIA). These have been extensively studied in pathogenic fungi that exist outside of host cells, but much less is known for intracellular fungal pathogens. Talaromyces marneffei is a dimorphic fungal pathogen endemic to Southeast Asia. In the host T. marneffei resides within macrophages where it grows as a fission yeast. T. marneffei has genes of both iron assimilation systems as well as a paralogue of the siderophore biosynthetic gene sidA, designated sidX. Unlike other fungi, deletion of sidA or sidX resulted in cell type‐specific effects. Mutant analysis showed that T. marneffei yeast cells also employ RIA for iron acquisition, providing an additional system in this cell type that differs substantially from hyphal cells. These data illustrate the specialized iron acquisition systems used by the different cell types of a dimorphic fungal pathogen and highlight the complexity in siderophore‐biosynthetic pathways amongst fungi.     

Random amplified polymorphic DNA (RAPD) analysis ofPenicillium marneffei strains isolated from AIDS patients in Thailand

Results of random amplified polymorphic DNA (RAPD) analysis using three different primers showed that 16 strains ofPenicillium marneffei isolated from AIDS patients in Thailand belonged to a genetically homogenous group, but different slightly from an isolate from bamboo rat in China. Six PCR fragments (from about, 200 to 600 bp) that were commonly observed in the RAPD fingerprint of all strains were extracted and sequented. Usefulness of this sequence information for identification ofP. marneffei is discussed.     

Mp1p Is a Virulence Factor in Talaromyces (Penicillium) marneffei

BackgroundTalaromyces marneffei is an opportunistic dimorphic fungus prevalent in Southeast Asia. We previously demonstrated that Mp1p is an immunogenic surface and secretory mannoprotein of T. marneffei. Since Mp1p is a surface protein that can generate protective immunity, we hypothesized that Mp1p and/or its homologs are virulence factors.Conclusions/SignificanceMp1p is a key virulence factor of T. marneffei. Mp1p mediates virulence by improving the survival of T. marneffei in macrophages.     

An inexpensive point-of-care immunochromatographic test for Talaromyces marneffei infection based on the yeast phase specific monoclonal antibody 4D1 and Galanthus nivalis agglutinin

Talaromyces marneffei is a thermally dimorphic fungus that causes opportunistic systemic mycoses in patients with AIDS or other immunodeficiency syndromes. The purpose of this study was to develop an immunochromatographic strip test (ICT) based on a solid phase sandwich format immunoassay for the detection of T. marneffei antigens in clinical urine specimens. The T. marneffei yeast phase specific monoclonal antibody 4D1 (MAb4D1) conjugated with colloidal gold nanoparticle was used as a specific signal reporter. Galanthus nivalis Agglutinin (GNA) was adsorbed onto nitrocellulose membrane to serve as the test line. Similarly, a control line was created above the test line by immobilization of rabbit anti-mouse IgG. The immobilized GNA served as capturing molecule and as non-immune mediated anti-terminal mannose of T. marneffei antigenic mannoprotein. The MAb4D1–GNA based ICT showed specific binding activity with yeast phase antigen of T. marneffei, and it did not react with other common pathogenic fungal antigens. The limit of detection of this ICT for T. marneffei antigen spiked in normal urine was approximately 0.6 μg/ml. The diagnostic performance of the ICT was validated using 341 urine samples from patents with culture- confirmed T. marneffei infection and from a control group of healthy individuals and patients with other infections in an endemic area. The ICT exhibited 89.47% sensitivity, 100% specificity, and 97.65% accuracy. Our results demonstrate that the urine-based GNA–MAb4D1 based ICT produces a visual result within 30 minutes and that the test is highly specific for the diagnosis of T. marneffei infection. The findings validate the deployment of the ICT for clinical use.     

Penicillium marneffei Infection: An Emerging Disease in Mainland China

Penicillium marneffei is an emerging pathogenic fungus that can cause a life-threatening systemic mycosis in immunocompromised hosts, especially in patients with AIDS. This infection is endemic in Southeast Asia. With the prevalence of AIDS in this area, the number of patients with systemic penicilliosis marneffei is found to be increasing rapidly in mainland China in recent years. We recently reviewed 668 cases of penicilliosis marneffei in mainland China from January 1984 to December 2009 in cnki, cqvip, CBMdisc and PubMed. We analyzed epidemiological and clinical features, laboratory findings, reaction to therapy and prognosis of the disease. We found that 99.4 % of the cases were reported in the southern part of China; among these cases, 42.8 % were from Guangxi (286 cases) and 40.6 % were from Guangdong province (271 cases). Five hundred and eighty-six cases (87.7 %) of penicilliosis marneffei were reported with infection by the human immunodeficiency virus, 25 cases (3.8 %) with other immunocompromised diseases, and 57 cases (8.5 %) without any documented underlying diseases. Fever, weight loss, anemia, lymphadenopathy, hepatosplenomegaly, respiratory signs and skin lesions were the common clinical manifestations of P. marneffei infections. The 569 cases received antifungal therapy with a mortality of 24.3 % (138 cases), 99 cases who had not received antifungal therapy had a mortality of 50.6 %. P. marneffei was an emerging pathogenic fungus and become a medical and public health importance in mainland China. The immunocompromised patients should pay more attention to P. marneffei infection in the endemic areas.     

Presence of weed fungus in a non‐social beetle–fungus cultivation mutualism

1. Farming by non‐human organisms has arisen independently in several animal lineages, allowing them to survive on food sources that are otherwise difficult to access. However, agricultural gardens are prone to invasion by parasites that overgrow cultivars in the absence of host animals. The presence of garden parasites and associated host adaptations are well studied in advanced fungal agriculture practised by social insects (ants, termites, and ambrosia beetles), but the impact of garden parasites in more primitive forms of agriculture is poorly known. The aim of the present study was to report the presence of weed fungi in fungal gardens of the non‐social lizard beetle Doubledaya bucculenta Lewis (Coleoptera: Erotylidae: Languriinae), which cultivates the yeast Wickerhamomyces anomalus (E.C. Hansen) Kurtzman, Robnett & Bas.‐Powers in the internodes of recently dead bamboo culms. 2. The filamentous fungi Arthrinium spp., Fusarium spp., and an unidentified species were isolated from the inner wall and insect‐made wall debris of bamboo internodes inhabited by the beetle. 3. When cultured together with the yeast in the absence of host larvae, Arthrinium sp.1 outcompeted the yeast, suggesting that this filamentous fungus can invade yeast gardens but is normally suppressed under natural conditions. 4. Rearing experiments showed that beetle larvae grew faster when grown on yeast cultures than when fed only Arthrinium sp.1. 5. These results suggest that Arthrinium sp.1 acts as a weed in the fungal gardens of D. bucculenta, inhibiting both growth of the beetle larvae and proliferation of the beneficial yeast.     

Characterization of nine polymorphic microsatellite loci in the fungus Botrytis cinerea (Ascomycota)

Nine microsatellite markers were characterized in the fungus Botrytis cinerea. Genomic DNA sequences from the partial sequencing of 12 000 bacterial artificial chromosome (BAC) clones, were screened by BLAST for various microsatellite motives, and primer pairs were designed. Cross‐amplification and polymorphism were assessed on 49 isolates from B. cinerea and two related species, collected from natural populations on several plants and locations.     

川蔓藻内生及根际细菌多样性与抑菌活性研究

该研究采用稀释涂布法结合形态观察、16S rRNA基因序列分析,对广西北海川蔓藻(Ruppia maritima)内生及根际细菌的物种多样性进行了研究,并采用琼脂扩散法和光度计法分析了其粗提物抑制马尔尼菲青霉菌活性。结果表明:从川蔓藻中分离到可培养内生细菌26株,根际可培养细菌31株。分别将内生细菌归属为10科12属13种,根际分离出细菌归属为9科14属19种,其中5株根际细菌可能为潜在新种。获得8株细菌对马尔尼菲青霉菌有抑制活性,总阳性率为25.0%。其中,菌株BGMRC 2015、BGMRC 2059、BGMRC 2043的粗提物表现出较强的抑制马尔尼菲青霉菌效果,其MIC分别为(1.800±0.045)、(1.881±0.061)、(1.604±0.021)mg·m L~(-1)。川蔓藻中可培养细菌具有较高的物种多样性,蕴藏着丰富的新物种资源,且富含抑菌活性良好的菌株。     

Evaluation of the Anti‐Diabetic Activity of Polysaccharide from Cordyceps cicadae in Experimental Diabetic Rats

Cordyceps cicadae is a medicinal fungus used in treating night sweat, childhood convulsions, vision improvement and pain. This study was designed to evaluate the anti‐diabetic activity of the crude polysaccharide (SHF) from the mycelium and body portion of C. cicadae. Diabetes mellitus was induced in the rat with a single intravenous injection of alloxan monohydrate (150 mg/kg). In other to evaluate the anti‐diabetic effects of C. cicadae polysaccharide in alloxan‐induced diabetic rats, the crude polysaccharide (SHF at 100, 200 and 400 mg/kg body weight) and glibenclamide were administered orally to diabetic rats for 30 days. Blood glucose level, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphate (ALP), creatinine (CREA), urea, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH) were determined. SHF showed significant reduction in blood glucose in diabetic rats. Treatment of diabetic rats also resulted an improvement in body weights, increased HDL, SOD and GSH, as well as decreased TC, TG, LDL, MDA, urea, CREA, ALT, AST and ALP. These results suggested that C. cicadae polysaccharide displayed anti‐hyperglycemic, anti‐hyperlipidemic and antioxidant activities and could be a promising therapeutic source in managing diabetes mellitus and its associated complications.     

Host genetic variation strongly influences the microbiome structure and function in fungal fruiting‐bodies

Despite increasing knowledge on host‐associated microbiomes, little is known about mechanisms underlying fungus‐microbiome interactions. This study aimed to examine the relative importance of host genetic, geographic and environmental variations in structuring fungus‐associated microbiomes. We analyzed the taxonomic composition and function of microbiomes inhabiting fungal fruiting‐bodies in relation to host genetic variation, soil pH and geographic distance between samples. For this, we sequenced the metagenomes of 40 fruiting‐bodies collected from six fairy rings (i.e., genets) of a saprotrophic fungus Marasmius oreades. Our analyses revealed that fine genetic variations between host fungi could strongly affect their associated microbiome, explaining, respectively, 25% and 37% of the variation in microbiome structure and function, whereas geographic distance and soil pH remained of secondary importance. These results, together with the smaller genome size of fungi compared to other eukaryotes, suggest that fruiting‐bodies are suitable for further genome‐centric studies on host–microbiome interactions.     

BIOCHEMICAL PHENOTYPES CORRESPONDING TO MOLECULAR PHYLOGENY OF THE RED ALGAE PLOCAMIUM (PLOCAMIALES,RHODOPHYTA): IMPLICATIONS OF INCONGRUENCE WITH THE CONVENTIONAL TAXONOMY1

Among five species of the genus Plocamium Lamouroux distributed around Japan, P. cartilagineum (Linnaeus) Dixon, P. recurvatum Okamura and P. telfairiae (Hooker and Harvey) Harvey are often difficult to distinguish morphologically from each other. Our previous study demonstrated that P. recurvatum and P. telfairiae were divided into two groups, A and C, based on RUBISCO spacer sequence and that the specimens belonging to group C had acidic cell saps. In this study, we inferred evolutionary relationships of these Plocamium species from internal transcribed spacer sequence of the ribosomal RNA genes and obtained a similar topology to the RUBISCO spacer tree. Color of the dried specimens in the acidic group C was darker red than that in the non‐acidic group A, although there was no difference in color in living thalli. The Br^? concentration in the cell sap of the acidic group C was 20 times higher than that of the non‐acidic group. We could not find any morphological differences to distinguish clearly between groups A and C despite exhaustive investigation of field‐collected and cultured thalli in both P. recurvatum and P. telfairiae. These results suggest that the color of dried specimens and the composition of intracellular inorganic ions are significant criteria for interpreting phylogenetic relationships in Japanese Plocamium spp.     

Indigenous Case of Disseminated Histoplasmosis from the <Emphasis Type="Italic">Penicillium marneffei</Emphasis> Endemic Area of China

This is the first indigenous case of disseminated histoplasmosis reported from the Penicillium marneffei endemic area in southern China. It was diagnosed by histopathology of tissue, gross and microscopic morphology of the culture and PCR assay of the isolated fungus. Successful antifungal treatment was with itraconazole 400 mg/day for 5 months. This case suggests that histoplasmosis should be an important differential diagnosis in immunocompromised patients in southern China and South East Asia (the only endemic area for P. marneffei).