“EFFECT OF ASPERGILLUS SPECIES ON SKIN INFECTION”

We present such a case, manifested by ulceration on skin due to A. niger, which remained undiagnosed for a prolonged period. Although the patient had associated severe fungal infection. Recurrence of the lesion occurred despite repeated anti-fungal therapies. Anti fungal testing was done based on the broth dilution (M-38A, AIIMS, INDIA) method. The culture isolate was found to be sensitive to fluconazole and amphotericin B. Continuation of antifungal therapy improved the symptoms, reducing the size of the lesion. Key words: Aspergillus niger, Skin infection, ulcer, Aspergillus lentulus., Broth dilution.

IDENTIFYING SPECIES AND DETERMINING ANTIFUNGAL RESISTANCE OF ASPERGILLUS ISOLATED FROM HUE HOSPITAL OF MEDICINE AND PHARMACY UNIVERSITY

Objectives: Identifying the species of Aspergillus isolated from patients and enviroment at Hue Hospital of Medicine and Pharmacy University; determining the resistance rate to antifungal drugs of common pathogen strains. Materials and methods: Samples were collected and identified follow morphology features, strains of Aspergillus were stored and checked by antifungal susceptibility testing. Results:6 species of Aspergillus were isolated from patients including A. terreus (58.1%), A. flavus (16.1%), A. niger (9.7%), A. versicolor (9.7%), A. fumigatus (3.2%), A. candidatus (3.2%). 9 species of Aspergillus were isolated from hospital enviroment including A. vesicolor, A. nidulans, A. sydowii, A. circumdati groups, A. restrictus, A. oryzae, A. ochraceus, A. flocculosus, A. japonicusIn antifungal susceptibility assays, 100% strains isolated from patients were susceptible to itraconazole. The resistance rate of A. terreus, A. flavus, A. niger to amphotericin B were 94.4%, 60% and 67% respectively. Voriconazole resistance of A. terreus, A. flavus, A. niger and A. versicolor were 66.7%, 20%, 67%, and 67% respectively. The propotion of caspofungi resistance were A. terreus (11.1%), A. flavus (40%) and A. versicolor (33%). Conclusion: A. terreus was the dominant species among isolates from patients of Hue Hospital of Medicine and Pharmacy University (58.1%). The appearance of A. versicolor and A. nidulans isolates from hospital environment might impact to human health. This pilot study displayed the extreme susceptibility of Aspergillus species to itraconazole. In addition, these isolates were highly resistant to amphotericin B and voriconazole. Key words: Aspergillus spp., anti-fungal drugs resistance, antifungal susceptibility testing

SELEKSI JAMUR TANAH PENDEGRADASI SELULOSA DAN PESTISIDA DELTAMETHRIN DARI BEBERAPA LINGKUNGAN DI KALIMANTAN BARAT

Telah dilakukan penelitian mengenai seleksi jamur tanah pengurai selulosa dan deltamethrin dari beberapa lingkungan di Kalimantan Barat. Tujuan penelitian untuk memperoleh isolat jamur yang mampu menguraikan selulosa dan pestisida deltamethrin. Sampel tanah diambil dari beberapa lingkungan ekstrim di Kalimantan Barat meliputi: tanah gambut, tanah kering, tanah pantai, tanah pertanian dan tanah mangrove. Setelah dilakukan isolasi diperoleh 79 nomor isolat. Sebanyak 72 isolat dapat membentuk clear zone pada media mengandung CMC 1%. Sejumlah 10 isolat membentuk clear zone berukuran besar. Jamur Aspergillus niger PS 1.4 dapat tumbuh paling baik pada media mengandung CMC 1% dengan menghasilkan bobot biomassa paling tinggi (0,7 g/L media). Jamur ini mempunyai aktivitas enzim selulase sebesar 0, 127 unit/ ml. Jamur Aspergillus niger PS 1.4 juga tumbuh pada beberapa pestisida: 50mg/L (ppm) Clorpirifos, 50 mg/L Cypermethrin dan 50mg/L Deltamethrin. Jamur Aspergillus niger PS1.4 dapat mendegradasi Deltamethrin sebanyak 90,2% dalam waktu 10 hari. Kata kunci: Aspergillus niger, deltamethrin, jamur tanah, penguraian, selulosa AbstractA research on selection of cellulose and deltamethrin degrading soil fungi from some environments in West Kalimantan had been done. The aim was to obtain isolates of fungi that have a high ability on decomposing cellulose and deltamethrin. The soil sample was taken from some environments in West Kalimantan, included: peatland,heath forest soil, sediment of manggrove, and coastal soil. Seventy two isolates were able to hydrolize CMC (Carboxy Methyl Cellulose). Aspergillus niger PS 1.4 was able to grow fastest among strains tested and yielded highest of mycelium. The fungi has cellulase activity was 0,127 unit/ml and able to grow on some pesticides also, included: 50 ppm Chlorpirifos, 50 ppm Cypermethrin and 50 ppm Deltamethrin. Aspergillus niger PS 1.4 was able to degrade deltamethrin as much as 90,2% in 10 days. Key words: Aspergillus niger, cellulose, deltamethrin, degradation, soil fungi

Citric Acid Future Prospects for Pakistan, a Short Review

Considered weak organic acid, Citric Acid (CA) finds its application in almost all the food and pharmaceutical industries as flavour, acidifier and chelating agent. CA has been found in abundance specially in citrus fruits, can also be produced by artificial means, most notably by fermentation using molasses or starch by the use of micro-organisms. The current paper outlines the production of CA from Aspergillus Niger (A. Niger) keeping in view the statistical analysis that shows its importance, usage and future scope of CA if manufactured at industrial scale in Pakistan. Key words: Aspergillus Niger, Citric Acid, Fermentation, Molasses.

Nitrogen metabolite repression in Aspergillus nidulans: an historical perspective

The paper of Arst and Cove (Mol. Gen. Genet. 126: 111 – 141, 1973) on "Nitrogen metabolite repression in Aspergillus nidulans" has influenced studies and perceptions of gene regulation in filamentous fungi during the past 21 years. Here I attempt to appraise the contributions of that paper and assess its role in further developments. Nitrogen metabolite repression, carbon catabolite repression, pathway-specific and integrated induction, as-acting regulatory mutations, a useful class of growth inhibitors, and a homologous Neurospora crassa gene are all discussed. Key words: Aspergillus nidulans, carbon catabolite repression, nitrogen metabolite repression.

Regulation of fungal extracellular proteases and their role in mammalian pathogenesis

Fungal infection in the immunocompromised host is a problem of increasing importance. The virulence determinants of Aspergillus fumigatus, the major agent of invasive aspergillosis, and of Candida albicans, causing candidiasis, are not well characterized. For both pathogens, the involvement of extracellular proteases in pathogenesis is discussed. The use of gene disruption techniques to inactivate the A. fumigatus alkaline protease and metalloprotease genes has led to the firm conclusion that neither of these enzymes has a significant role in virulence. The diploid nature of C. albicans (necessitating sequential inactivation of both alleles for gene disruption studies) and the presence of a multigene family encoding secreted aspartyl proteases has hampered progress in understanding the role of proteases in virulence. We discuss the involvement of wide-domain regulators in the control of protease production and give an example of how one of these regulators (encoded by the areA gene) has been used in virulence studies. Key words: Aspergillus, Candida, proteases, gene regulation.

Analysis of cell cycle regulation using Aspergillus nidulans

Aspergillus nidulans has proved to be an excellent model system to help unravel the genetic and biochemical control systems that regulate the cell cycle. Many genes that specifically affect progression through G2 into mitosis have been isolated. Study of these genes has helped to formulate concepts about how the cell cycle is regulated. The existence of regulatory networks involving protein phosphorylation and dephosphorylation has been realized, and how the kinases and phosphatases of these networks ensure correct order and timing through the cell cycle is beginning to be understood. Our studies indicate that activation of two protein kinases is essential for progression into mitosis. One, the universal p34cdc2 H1 kinase, has been well studied in many systems and is considered the key activator of mitotic initiation. However, in the absence of the NIMA protein kinase p34cdc2 cannot promote mitosis. How these two mitotic kinases interact is therefore of great importance to our understanding of cell cycle regulation. The contribution of studies using A. nidulans to the formulation of concepts about how the cell cycle is regulated is the topic of this paper. Key words: Aspergillus nidulans, cell cycle regulation, protein kinase, NIMA, p34cdc2, cyclinB, Cdc25.

Influence of pH on endo- and exo-pectinase production by Aspergillus sp. CH-Y-1043

Aspergillus sp. CH-Y-1043 grown on pectins with various degrees of esterification produces endo- and exo-pectinases at pH values as low as 2.5. Maximal production was attained at this pH, although fungal growth only approximated 50% of that obtained at higher pH values. Endopectinase was produced at pH 2.5–3.5 when the fungus was grown on low degree esterified pectin. With higher degree esterified pectin this enzyme was produced at all pH values analyzed. Exopectinase production was less affected by pH values. Still, maximal production was also reached at pH 2.5–3.5. Exopectinase was found to be associated to the cell and could be released after incubation at different pH values, whereas endo pectinase was not detected in the cellular fraction. Results confirmed by SDS–PAGE coupled with in situ activity assays in pectin–agarose gels allowed the identification of a protein band corresponding to endopectinase and a band with pectin esterase activity. Stability of Aspergillus sp. CH-Y-1043 pectinases at various pH values was also evaluated. Key words: Aspergillus sp. CH-Y-1043, extreme acidic pH pectinase production, in situ pectinase detection, cell-associated exopectinase.

Vegetative compatibility and genetic diversity in the Aspergillus flavus population of a single field

Aspergillus flavus was isolated from soil from a single Arizona cotton field in 1987, 1988, and 1989. Isolates from infected cotton bolls were collected from the same field in 1988. Isolates were assigned to vegetative compatibility groups via complementation tests between nitrate-nonutilizing mutants. Sixty-one of 105 isolates composed 13 vegetative compatibility groups; the remaining 44 isolates could not be assigned to groups. Forty-three isolates from other fields in Arizona composed 21 groups, 6 of which were also found in the test field. Distribution of vegetative compatibility groups in and outside the field was significantly different, based on a G-test. One vegetative compatibility group included 20% of all isolates from the test field, but was not found elsewhere. It was common in the test field in 1987 and 1988, but was not found in 1989. Boll and soil populations from 1988 were not significantly different. Single infected boll locules and 25-g soil samples often contained A. flavus individuals from more than one group. These results suggest that although many vegetative compatibility groups are widely distributed, a single field may have a unique population profile that changes significantly from year to year. Key words: Aspergillus flavus, vegetative compatibility, Nit−, imperfect fungi.

Characterization of interspecific hybrids within the Aspergillus nidulans group by isoenzyme analysis

A comparison of interspecific hybrids within the Aspergillus nidulans species group was made by isoenzyme analysis. The gel electrophoretic patterns of the parental species were distinct for most of the enzymes tested. The hybrids were distinguishable from their parents by isoenzyme patterns. The appearance of novel bands in all the interspecific hybrids indicated that nuclear fusion could have occurred. In most hybrids the appearance of the parental bands showed nonpreferential, partial chromosome loss or repressive interaction between the genomes. The isoenzyme composition of the haploid segregants of the Aspergillus nidulans × Aspergillus rugulosus hybrid differed for some of the enzymes studied from that of the hybrid, suggesting that during segregation further interaction of the chromosomes took place. The results indicate a certain degree of genetic homology among the members of the Aspergillus nidulans species group. Key words: Aspergillus, isoenzyme analysis, hybridization.