A. A. Haleem Khan

Bio: A. A. Haleem Khan is an academic researcher from DST Systems. The author has contributed to research in topics: Indoor air quality & Sick building syndrome. The author has an hindex of 3, co-authored 3 publications receiving 197 citations.

Isolation, identification and testing for allergenicity of fungi from air-conditioned indoor environments

Abstract: Twelve fungi were isolated and identified from air-conditioned rooms Of the 12, 7 were species of Aspergillus, viz A niger, A oryzae, A fumigatus, A terreus, A nidulans, A versicolor and A parasiticus Other fungi were Penicillium citrinum, Fusarium oxysporum, Trichoderma viride, Neurospora crassa and Alternaria alternata A niger was present in 80% of the locations Some of the fungi isolated in this study could be opportunistic fungal pathogens, like A fumigatus,A niger and Penicillium citrinum, and were found to be allergenic Results of this study indicate that air-conditioned rooms could be reservoirs of fungi and may cause allergic problems or infections in healthy or immunocompromised individuals living in these environments

Practices contributing to biotic pollution in Air-conditioned indoor environments

Abstract: Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. The term ‘sick building syndrome’ (SBS) describes causes of building occupants experiencing adverse health effects that appear to be linked to the time spent in a building. Questionnaire-based data were collected from the people who live or work in air-conditioned (A/C) rooms. Responses of the occupants were analyzed to understand the practices contributing to biotic pollution of indoor air-conditioned environments. Our survey revealed some interesting facts about the users of A/C rooms and their practices that may be contributing to the indoor air quality. The allergy complaints and use of anti-allergy medicines were noted commonly among the occupants of government (Govt.) organizations and computer training centers where cleaning of room and A/C filters were not done periodically. Cleaning practices may reduce the complaints.

Plasma assisted surface modification of organic biopolymers to prevent bacterial attachment

Abstract: Despite many synthetic biomaterials having physical properties that are comparable or even superior to those of natural body tissues, they frequently fail due to the adverse physiological reactions they cause within the human body, such as infection and inflammation. The surface modification of biomaterials is an economical and effective method by which biocompatibility and biofunctionality can be achieved while preserving the favorable bulk characteristics of the biomaterial, such as strength and inertness. Amongst the numerous surface modification techniques available, plasma surface modification affords device manufacturers a flexible and environmentally friendly process that enables tailoring of the surface morphology, structure, composition, and properties of the material to a specific need. There are a vast range of possible applications of plasma modification in biomaterial applications, however, the focus of this review paper is on processes that can be used to develop surface morphologies and chemical structures for the prevention of adhesion and proliferation of pathogenic bacteria on the surfaces of in-dwelling medical devices. As such, the fundamental principles of bacterial cell attachment and biofilm formation are also discussed. Functional organic plasma polymerised coatings are also discussed for their potential as biosensitive interfaces, connecting inorganic/metallic electronic devices with their physiological environments.

Recent Developments in Antimicrobial Polymers: A Review

Abstract: Antimicrobial polymers represent a very promising class of therapeutics with unique characteristics for fighting microbial infections. As the classic antibiotics exhibit an increasingly low capacity to effectively act on microorganisms, new solutions must be developed. The importance of this class of materials emerged from the uncontrolled use of antibiotics, which led to the advent of multidrug-resistant microbes, being nowadays one of the most serious public health problems. This review presents a critical discussion of the latest developments involving the use of different classes of antimicrobial polymers. The synthesis pathways used to afford macromolecules with antimicrobial properties, as well as the relationship between the structure and performance of these materials are discussed.

Phylogenetic reassessment of Nigrospora: Ubiquitous endophytes, plant and human pathogens.

Abstract: Species of Nigrospora commonly occur as plant pathogens, endophytes or saprobes, and have been shown to be extremely interesting for the discovery of novel metabolites. The familial placement, as well as phylogenetic relationships among Nigrospora species remain ambiguous. In this study, Nigrospora (= Khusia) is confirmed as a monophyletic genus belonging to Apiosporaceae (Xylariales), based on a phylogeny inferred from LSU sequence data. A multi-locus phylogeny based on ITS, TEF1-α and TUB2, in conjunction with morphological characters, host associations, and ecological data was employed for species delimitation in Nigrospora, as well as identification of 165 recently collected isolates from China, and three from Europe. In total 13 novelties are proposed including 12 new species and 1 new combination. Five species are re-described based on an examination of type specimens and/or fresh collections. New species described in this paper include: N. aurantiaca, N. bambusae, N. camelliae-sinensis, N. chinensis, N. guilinensis, N. hainanensis, N. lacticolonia, N. osmanthi, N. pyriformis, N. rubi, N. vesicularis and N. zimmermanii. Furthermore, N. vietnamensis is transferred to Arthrinium. Our results indicate a high level of species diversity within Nigrospora, with a general lack in host specificity. Taxa that cluster basal in Nigrospora have wide host ranges, whereas those that diverged later tend to have narrow host ranges. The currently available data suggest, therefore, that the general evolutionary direction in the genus Nigrospora is from a wide to a narrow host range.