Identification and distribution of aeromycoflora in the indoor environment of Shyambazar Metro-Railway Station, Kolkata, India

Fungal pollution of indoor environments and its management.

Abstract: Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. Life style changes have resulted in a shift from open air environments to air tight, energy efficient, environments, in which people spend a substantial portion of their time. Most indoor air pollution comes from the hazardous non biological agents and biological agents. Fungi are ubiquitous in distribution and are a serious threat to public health in indoor environments. In this communication, we have reviewed the current status on biotic indoor air pollution, role of fungi as biological contaminants and their impact on human health.

Study of aeromycoflora in indoor and outdoor environment of national library, kolkata

Abstract: We aimed at the systematic evaluation of air-borne fungal flora of the National Library, Kolkata for a period of three months beginning from February to April, 2010 to determine their identification, concentration and diversity in both indoor and outdoor environment to understand the cumulative aeromycoflora composition. The period of study was the post winter period followed by pre-summer months that was mild to moderate warm and low to high humid condition with temperature and humidity ranges of 17.0-38.2°C and 26-92% respectively. Air sample was collected with interval of two weeks by means of gravitational settling method using petri dishes with Malt Extract Agar (MEA) media. Fungal colonies that formed after 3-5 days incubation period at 25-28°C were identified on the basis of micro and macro morphological characteristics and finally percentage contributions of individual fungal species were calculated. A total of 21 types of fungal spores were identified from indoor environment with 5 sterile hyphae and 13 unidentified spore types. In case of outdoor environment, total number of spore types encountered was 19 along with 12 sterile hyphae and 6 miscellaneous types were recorded under unidentified spore type. The prevailing presence of Aspergillus niger, Alternaria tenuissima, Cladosporium herbarum and Penicillium sp. were accounted for a high percentage in indoor environment whereas outdoor environment showed clear dominance of Alternaria alternata, Asperillus niger, Alternaria tenussima, Cladosporium herbarum, Cladosporium cladosporioides, Curvularia lunata and Fusarium oxysporum. Among all the fungal spore types the taxonomic group Deuteromycotina showed dominance in total spore contribution. Biomonitoring of aeromycoflora is a key to open the information of sensitivity towards bioaerosol in this atmosphere and our findings may be useful with regard to the investigation of corrective measures to save the library materials from fungal damage and diagnosis and prophylaxis of allergic diseases resulting from aeromycoflora composition of this environment.

Temporal Dynamics of Air Bacterial Communities in a University Health Centre Using Illumina MiSeq Sequencing

Abstract: Bacterial contamination of air may have human health implications by the transmission of potential human pathogens. Therefore, assessment of air bacterial abundance and composition in different built environment is essential. Jawaharlal Nehru University health centre (UHC) is a primary healthcare setting providing need-based medication to university students. Using active air sampling method, we collected eight air samples from the indoor and outdoor area of UHC across four different seasons. The total genomic DNA was extracted from the air samples and subjected to 16S rRNA gene-based next-generation sequencing. We performed the taxonomic classification along with comparative analysis of air bacterial communities. This study revealed that Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes are the dominant phyla in the sampled air. Overall, the air bacterial composition in our studied samples was comparatively simple; only ten taxonomic families accounting for ~75% of the total sequences determined. We also observed ESKAPE pathogens in the air metagenomes in a low percentage (4.42%), which were dominated by Pseudomonas, Acinetobacter and Staphylococcus. Proteobacteria, Actinobacteria and Firmicutes showed significant correlation with PM2.5. We suggest that routine air monitoring and microbiological survey is essential for air quality standards and potential human pathogens detection in health care settings. It is the first report from India to uncover the temporal dynamics of air bacterial communities in UHC using Illumina MiSeq (PE300) sequencing and Quantitative Insights into Microbial Ecology (QIIME).

Comparative studies on indoor Aeromycoflora from the laboratories

Abstract: Copyright: © 2014 | Author(s), This is an open access article under the terms of the Creative Commons AttributionNon-Commercial No Derivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is noncommercial and no modifications or adaptations are made. Laboratory is the basic need of scientific research provided with several equipments, materials including cellulosic and non-cellulosic substrates. These substrates are degraded by diverse group of fungal microbes in a set of climate, indirectly polluting the indoor environment. In the present study aeromycoflora from various laboratories was reported for a month at an interval of a week. A population of 3368 fungal colonies falls under 19 genera and 28 species have been confined by culture plate exposer method. Ascomycota contributed with more than half of the total colonies recorded while Oomycota had least colonies. Zygomycota and Deuteromycota contributed moderate count of colonies. No member of Basidiomycota did persist. Aspergillus had higher colony count as well as greater species number. The sub-dominant air spora included Cladosporium cladosporoides, Mucor pusillus and Rhizopus stolonifer. The genus Fusarium had 3 species; Penicillium, Curvularia, Alternaria recorded with 2 species and others with single species. Prevalence of diverse group of fungal organisms on cellulosic material in laboratories depends on changing indoor environment. The climate of Lab IV was comparatively more ideal for fungal sporulation during survey

Abundance of airborne Penicillium CFU in relation to urbanization in Mexico City.

Abstract: Air was sampled simultaneously at three localities in Mexico City differing in urbanization index and air pollution level on 22 days during a period covering both dry and rainy seasons. An Andersen two-stage microbial sampler was used for 15 min at 28 liters min-1 to isolate culturable fungi on malt extract agar. After exposure, plates were incubated at 25 degrees C for 48 to 72 h before colonies were counted and identified to give concentrations of total fungal spores and of Penicillium spp., expressed as CFU per cubic meter of air. Total fungi numbered 91 to 602 CFU m-3 in Tlalpan Borough (southern area), 40 to 264 CFU m-3 in Cuauhtemoc Borough (downtown), and 26 to 495 CFU m-3 in Gustavo A. Madero Borough (northern area). Although Penicillium spp. were the second most frequently isolated fungal genus, concentrations were small, with a maximum of only 133 CFU m-3. Twice as many colonies were isolated in the southern area, with an urbanization index of 0.25 (arithmetic mean, 41 CFU m-3), as at other sampling stations with greater urbanization indices (arithmetic means, 19 and 20 CFU m-3). In the downtown area, with an urbanization index of 1.0, Penicillium spp. were more numerous than any other genus and formed 25% of the total fungal count compared with 14 and 17% in the other areas. Concentrations of airborne Penicillium spp. did not differ significantly between rainy and dry seasons.(ABSTRACT TRUNCATED AT 250 WORDS)

The isolation of mutants of Aspergillus flavus and A.parasiticus with altered aflatoxin producing ability.

Abstract: Mutations affecting the production of aflatoxin might be useful in studying its biosynthesis, and in understanding the wide variation in aflatoxigenicity of fungal strains isolated from nature. Two methods of isolating mutants of Aspergillus in which aflatoxin production is attenuated or lost are presented. In one method mutants are selected on the basis of altered fluorescence under ultraviolet light. The second method utilizes a mutant strain which produces aflatoxin and an orange-red mycelial pigment not detected in the wild type. Unpigmented mutants derived from this strain exhibit lowered or lost aflatoxigenicity.

Effect of Corn Steep Liquor on Mycelial Growth and Aflatoxin Production in Aspergillus parasiticus

Abstract: Total aflatoxin concentrations produced by Aspergillus parasiticus, isolate 64-R8, in Czapek9s broth fortified with corn steep liquor increased proportionately as the concentration of corn steep was increased from 0.5 to 8.0% (v/v) until maximal growth, as measured by dry mycelial weight, was reached. Thereafter, aflatoxin concentrations declined more rapidly than the rate of autolysis of mycelial material. Data are presented which indicate that the concentration of corn steep liquor also affects the ratio of production of aflatoxin B1 and B2 to that of aflatoxin G1 and G2. Further, this ratio also varies with time of incubation. Although both growth of the fungus and aflatoxin production are stimulated by the addition of corn steep to the basic medium, the stimulation of toxin production is much greater than fungus growth.