Comparison of Antibiotic Resistance, Biofilm Formation and Conjugative Transfer of Staphylococcus and Enterococcus Isolates from International Space Station and Antarctic Research Station Concordia

Abstract

The International Space Station (ISS) and the Antarctic Research Station Concordia are confined and isolated habitats in extreme and hostile environments. The human and habitat microflora can alter due to the special environmental conditions resulting in microbial contamination and health risk for the crew. In this study, 29 isolates from the ISS and 55 from the Antarctic Research Station Concordia belonging to the genera Staphylococcus and Enterococcus were investigated. Resistance to one or more antibiotics was detected in 75.8 % of the ISS and in 43.6 % of the Concordia strains. The corresponding resistance genes were identified by polymerase chain reaction in 86 % of the resistant ISS strains and in 18.2 % of the resistant Concordia strains. Plasmids are present in 86.2 % of the ISS and in 78.2 % of the Concordia strains. Eight Enterococcus faecalis strains (ISS) harbor plasmids of about 130 kb. Relaxase and/or transfer genes encoded on plasmids from gram-positive bacteria like pIP501, pRE25, pSK41, pGO1 and pT181 were detected in 86.2 % of the ISS and in 52.7 % of the Concordia strains. Most pSK41-homologous transfer genes were detected in ISS isolates belonging to coagulase-negative staphylococci. We demonstrated through mating experiments that Staphylococcus haemolyticus F2 (ISS) and the Concordia strain Staphylococcus hominis subsp. hominis G2 can transfer resistance genes to E. faecalis and Staphylococcus aureus, respectively. Biofilm formation was observed in 83 % of the ISS and in 92.7 % of the Concordia strains. In conclusion, the ISS isolates were shown to encode more resistance genes and possess a higher gene transfer capacity due to the presence of three vir signature genes, virB1, virB4 and virD4 than the Concordia isolates.

Microbial Monitoring of Crewed Habitats in Space—Current Status and Future Perspectives

“…Therefore, the antibiotic resistance of staphylococci and enterococci isolated from the ISS was determined. In a collection of ISS isolates from sampling campaigns between 2002 and 2006, twenty-nine Staphylococcus and Enterococcus isolates were investigated for antibiotic resistance, horizontal transfer capability, and biofilm formation (46). Resistance to one or more antibiotics was detected in 22 out of 29 (75.8%) strains examined.…”

“…Resistance to one or more antibiotics was detected in 22 out of 29 (75.8%) strains examined. The most prevalent resistance determinants among the staphylococci were ermC , tetK , and different cat genes conferring resistance to macrolide, tetracycline, and chloramphenicol, respectively (46). Plasmids were present in 86.2% of the isolates; eight of the Enterococcus faecalis isolates harbored a large plasmid of approximately 130 kb, likely to be self-transmissible.…”

“…isolates could transfer their resistance genes to distinct Enterococcus and Staphylococcus spp. Biofilm formation was observed in 83% of the isolates (46). As methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) was not detected, the health risk associated with Enterococcus and Staphylococcus infections for the crew was assessed as low.…”

The Plasmidome of Firmicutes: Impact on the Emergence and the Spread of Resistance to Antimicrobials

“…One branch comprises plasmids of Staphylococcus that harbor tetK (rep 7 ) and catA8/ catA7 (rep 7b ) with different MOB genes. Such plasmids have been reported in S. aureus since their first detection in the early 1950s (84) and were eventually described in contemporary E. faecalis isolates (68,85). A second branch contains pRI1-like plasmids (rep 14 ), which correspond to plasmids of different enterococcal species (E. faecium, Enterococcus hirae, Enterococcus mundtii) isolated from foodborne animals and hospital patients (7,59,71,86).…”

Evaluation of Acquired Antibiotic Resistance in Escherichia coli Exposed to Long-Term Low-Shear Modeled Microgravity and Background Antibiotic Exposure

“…These include studies done on diverse organisms, including the pathogens Pseudomonas aeruginosa (23,24), Salmonella enterica serovar Typhimurium (25), Streptococcus mutans (26), Yersinia pestis (21,27), the yeast Candida albicans (28), Serratia marcescens (18), Enterobacter cloacae (18), Enterococcus faecalis (29), pathogenic Escherichia coli (30)(31)(32), nonpathogenic E. coli (33)(34)(35)(36)(37)(38), and microbial isolates (opportunistic pathogens P. fluorescens, Stenotrophomonas maltophilia, and Chryseobacterium spp.) from water systems of the Mir Space Station (39,40) or from the International Space Station (ISS) (Enterobacter bugandensis and staphylococcal and enterococcal strains) (41,42) or on the space station MIR (31).…”