Bacterial Population in Russian Space Station “Mir”

We had the opportunity to investigate the bacterial population in air samples, condensation water, and inner wall swabs from the Russian space station Mir. From the first and second air samples during the mission, 29 and 7 bacterial colonies were collected, respectively. The values were equivalent to 16.8 and 4.0 cfu/100 liter air, respectively. Condensation water was collected from three different sites. The total viable bacterial counts were 2.1 × 106, 5.2 × 102, and 3.0 × 101 cfu/ml. The phylogenetic position of each isolate was determined by total 16S rDNA sequencing. Bacteria from air samples were mainly Gram‐positive (35/36 colonies), and staphylococci occupied dominant specifically (23/36 colonies). On the other hand, Gram‐negative bacteria were mainly isolated from condensation water samples. Most strains were thought to be opportunistic pathogens or environmental bacteria (such as those that inhabit soil, water, or air) found on earth. However, 6 of 23 isolates were suspected to be new species according to phylogenetic analysis and quantitative DNA‐DNA hybridization data. The isolation of the other levels 3 and 2 bacteria, using specific selective media, was unsuccessful because all samples were heavily contaminated with fungi. To overcome this situation, PCR methods were applied to survey most levels 3 and 2 pathogenic bacteria in the condensation water samples. Up to 380 different primers for bacterial pathogens were used in this study. Only Mycobacterium avium 16S DNA sequences, however, could be amplified from the three water samples. The average bacteria count was estimated to be about 104 organisms/ml water.

[1]  T. Ezaki,et al.  Distribution of Staphylococcus Species among Human Clinical Specimens and Emended Description ofStaphylococcus caprae , 1998, Journal of Clinical Microbiology.

[2]  H. D. Brown,et al.  Gram staining apparatus for space station applications , 1990, Applied and environmental microbiology.

[3]  Takayuki Ezaki,et al.  Fluorometric Deoxyribonucleic Acid-Deoxyribonucleic Acid Hybridization in Microdilution Wells as an Alternative to Membrane Filter Hybridization in which Radioisotopes Are Used To Determine Genetic Relatedness among Bacterial Strains , 1989 .

[4]  L. Lerman,et al.  Length-independent separation of DNA restriction fragments in two-dimensional gel electrophoresis , 1979, Cell.

[5]  Y. Kodera,et al.  Molecular diagnostic detection of free cancer cells in the peritoneal cavity of patients with gastrointestinal and gynecologic malignancies , 1999, Cancer Chemotherapy and Pharmacology.

[6]  D. Lipman,et al.  Improved tools for biological sequence comparison. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[7]  T. Ezaki,et al.  16S ribosomal DNA sequences of anaerobic cocci and proposal of Ruminococcus hansenii comb. nov. and Ruminococcus productus comb. nov. , 1994, International journal of systematic bacteriology.

[8]  Erko Stackebrandt,et al.  Taxonomic Note: A Place for DNA-DNA Reassociation and 16S rRNA Sequence Analysis in the Present Species Definition in Bacteriology , 1994 .

[9]  J. Thompson,et al.  CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. , 1994, Nucleic acids research.

[10]  Roderic D. M. Page,et al.  TreeView: an application to display phylogenetic trees on personal computers , 1996, Comput. Appl. Biosci..

[11]  J. Decelle,et al.  Autoflora in the upper respiratory tract of Apollo astronauts , 1976, Applied and environmental microbiology.

[12]  T Ezaki,et al.  Fungal Flora on Board the Mir‐Space Station, Identification by Morphological Features and Ribosomal DNA Sequences , 2001, Microbiology and immunology.

[13]  T. Ezaki,et al.  [Rapid and direct detection of Mycobacterium tuberculosis complex and mycobacteria in sputum by advanced method, PCR]. , 1992, Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases.

[14]  C. A. Berry,et al.  View of human problems to be addressed for long-duration space flights. , 1973, Aerospace medicine.

[15]  A. Uitterlinden,et al.  Profiling of complex microbial populations by denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genes coding for 16S rRNA , 1993, Applied and environmental microbiology.

[16]  J R Puleo,et al.  Quantitative and qualitative microbiological profiles of the Apollo 10 and 11 spacecraft. , 1970, Applied microbiology.

[17]  T Ezaki,et al.  Streptococcus peroris sp. nov. and Streptococcus infantis sp. nov., new members of the Streptococcus mitis group, isolated from human clinical specimens. , 1998, International journal of systematic bacteriology.