Characteristics of Airborne Actinomycete Spores

ABSTRACT Airborne actinomycete spores, important contaminants in occupational and residential environments, were studied with respect to their (i) release into the air, (ii) aerodynamic and physical size while airborne, and (iii) survival after collection onto agar with an impactor. Three actinomycete species were selected for the tests to exemplify the three main spore types: Streptomyces albusfor arthrospores, Micromonospora halophytica for aleuriospores, and Thermoactinomyces vulgaris for endospores. The results show that the incubation conditions (temperature, time, and nutrients) needed for the development of spores for their release into air are different from the conditions that are needed for colony growth only. Additional drying of M. halophytica and T. vulgaris cultures was needed before spores could be released from the culture. The aerodynamic sizes of the spores, measured with an aerodynamic particle sizer, ranged from 0.57 (T. vulgaris) to 1.28 μm (M. halophytica). The physical sizes of the spores, when measured with a microscope and an image analysis system, were found to be smaller than previously reported in the literature. The relative recovery of the spores on agar media ranged from 0.5 (T. vulgaris) to 35% (S. albus). The results indicate that the culturability of the collected airborne actinomycete spores varies widely and is affected by several variables, such as the species and the sampling flow rate. Therefore, alternatives to commonly used cultivation methods need to be developed for the enumeration of actinomycete spores.

[1]  K Willeke,et al.  Effect of impact stress on microbial recovery on an agar surface , 1995, Applied and environmental microbiology.

[2]  Pertti Pasanen,et al.  Significance of air humidity and air velocity for fungal spore release into the air , 1991 .

[3]  Tiina Reponen,et al.  The indoor air quality in finnish homes with mold problems , 1991 .

[4]  F. A. Skinner,et al.  FARMER'S LUNG. THERMOPHILIC ACTINOMYCETES AS A SOURCE OF "FARMER'S LUNG HAY" ANTIGEN. , 1963, Lancet.

[5]  L. V. Kalakoutskii,et al.  Comparative aspects of development and differentiation in actinomycetes. , 1976, Bacteriological reviews.

[6]  J. Dutkiewicz,et al.  Isolation of Actinomycetes and fungi from mouldy hay using a sedimentation chamber. , 1976, The Journal of applied bacteriology.

[7]  Klaus Willeke,et al.  Dynamic size spectrometry of airborne microorganisms: Laboratory evaluation and calibration , 1995 .

[8]  B. Crook,et al.  Fungal and actinomycete spores as pollutants of the workplace and occupational allergens. , 1988, The Annals of occupational hygiene.

[9]  K. Savolainen,et al.  Streptomyces spores from mouldy houses induce nitric oxide, TNFα and IL-6 secretion from RAW264.7 macrophage cell line without causing subsequent cell death. , 1997, Environmental toxicology and pharmacology.

[10]  W. Jones,et al.  Evaluation of the Andersen viable impactor for single stage sampling. , 1985, American Industrial Hygiene Association journal.

[11]  V. Kurup,et al.  Streptomyces albus: a new cause of hypersensitivity pneumonitis. , 1981, The Journal of allergy and clinical immunology.

[12]  K Willeke,et al.  Factors affecting microbiological colony count accuracy for bioaerosol sampling and analysis. , 1995, American Industrial Hygiene Association journal.

[13]  L. V. Kalakoutskii,et al.  Comparative aspects of development and differentiation in actinomycetes , 1976 .

[14]  H. E. Johnson,et al.  Fungal and actinomycete spore aerosols measured at different humidities with an aerodynamic particle sizer. , 1992, The Journal of applied bacteriology.

[15]  T. Cross.  Thermophilic actinomycetes. , 1968, The Journal of applied bacteriology.

[16]  A. Lloyd.  Dispersal of Streptomycetes in air. , 1969, Journal of general microbiology.

[17]  T. Reponen,et al.  Techniques for Dispersion of Microorganisms into Air , 1997 .

[18]  G. Stelma,et al.  Comparison of methods for detection and enumeration of airborne microorganisms collected by liquid impingement , 1996, Applied and environmental microbiology.

[19]  Robert A. Samson,et al.  Health Implications of Fungi in Indoor Environments , 1994 .

[20]  J. Ensign.  Formation, properties, and germination of actinomycete spores. , 1978, Annual review of microbiology.

[21]  E. Terho,et al.  Microbiological and serological studies of farmers' lung in Finland , 1979, Clinical allergy.

[22]  M. Kotimaa,et al.  Airborne molds and actinomycetes in the work environment of farmer's lung patients in Finland. , 1984, Scandinavian journal of work, environment & health.

[23]  J. Dutkiewicz,et al.  Bioaerosols and occupational lung disease , 1994 .

[24]  A. Verhoeff,et al.  Assessment of fungi in carpeted environments. , 1994 .

[25]  S. Gravesen,et al.  Health implications of fungi in indoor environments. , 1994 .

[26]  J. Macher,et al.  Positive-hole correction of multiple-jet impactors for collecting viable microorganisms. , 1989, American Industrial Hygiene Association journal.

[27]  K. Willeke,et al.  Impaction onto a Glass Slide or Agar versus Impingement into a Liquid for the Collection and Recovery of Airborne Microorganisms , 1994, Applied and environmental microbiology.

[28]  F. A. Skinner,et al.  Actinomycetales: characteristics and practical importance , 1973 .

[29]  D. Sharp.  Environmental influences on reproduction in horses. , 1980, The Veterinary clinics of North America. Large animal practice.

[30]  S. Williams,et al.  The fine structure of the Actinomycetales. , 1973, Society for Applied Bacteriology symposium series.

[31]  Robert A. Samson,et al.  Health Implications of Fungi in Indoor Environments, Air Quality Monographs. Vol. 2 , 1997 .