biostudies-literatureUnknown14Mohammadi BCharacterization of the microbiomes of pre-launch spacecraft in spacecraft assembly facilities is an important step in keeping crews healthy during journeys that can last several hundred days in small artificial environments in space. <i>Bacillus cereus</i>, a foodborne pathogenic bacterium, has the potential to be a significant source of food contamination in such environments. This bacterium is a spore-forming bacteria that resists different antimicrobial treatments in cleanrooms where spacecraft are assembled. This study evaluated 41 <i>B. cereus</i> isolates from four pre-launch spacecraft in spacecraft assembly facilities for their toxin gene profile and antibiotic resistance. Four enterotoxin genes (<i>hlbC</i>, <i>cytK</i>, <i>nheA</i>, and <i>entFM</i>) and two emetic toxin genes (<i>ces</i> and <i>CER</i>) were targeted for chromosomal DNA and plasmid DNA. Results showed 31.7, 7.3, 85, and 41.5% of isolates contained <i>hblC</i>, <i>cytK</i>, <i>nheA</i>, and <i>entFM</i>, respectively, in chromosomal or plasmid DNA. Overall, 37 isolates (90.2%) showed at least one enterotoxin gene. The emetic toxin gene, <i>ces</i>, was detected in the plasmid DNA of three isolates (7.3%). The antibiotic resistance of isolates was evaluated by the Kirby-Bauer disk diffusion procedure. All the isolates exhibited 100% susceptibility to gentamicin, 97% were susceptible to clindamycin, and 95% to chloramphenicol, imipenem, tetracycline, and vancomycin. The overall susceptibility average is 51%. However, 98% of the isolates were resistant to β-lactam antibiotics, 97.5% were resistant to sulfamethoxazole/trimethoprim, and 80% were resistant to rifampin. This study provides important information on <i>B. cereus</i> isolates from spacecraft assembly facilities for use in microbial monitoring programs of spacecraft.Frontiers in microbiology1231726https://www.ebi.ac.uk/biostudies/studies/S-EPMC10690612biostudies-literatureProfiling toxin genes and antibiotic resistance in <i>Bacillus cereus</i> isolated from pre-launch spacecraft.PMC10690612Mohammadi BSmith SAGorkina NPerez-Reyes MEfalseProfiling toxin genes and antibiotic resistance in <i>Bacillus cereus</i> isolated from pre-launch spacecraft.Characterization of the microbiomes of pre-launch spacecraft in spacecraft assembly facilities is an important step in keeping crews healthy during journeys that can last several hundred days in small artificial environments in space. <i>Bacillus cereus</i>, a foodborne pathogenic bacterium, has the potential to be a significant source of food contamination in such environments. This bacterium is a spore-forming bacteria that resists different antimicrobial treatments in cleanrooms where spacecraft are assembled. This study evaluated 41 <i>B. cereus</i> isolates from four pre-launch spacecraft in spacecraft assembly facilities for their toxin gene profile and antibiotic resistance. Four enterotoxin genes (<i>hlbC</i>, <i>cytK</i>, <i>nheA</i>, and <i>entFM</i>) and two emetic toxin genes (<i>ces</i> and <i>CER</i>) were targeted for chromosomal DNA and plasmid DNA. Results showed 31.7, 7.3, 85, and 41.5% of isolates contained <i>hblC</i>, <i>cytK</i>, <i>nheA</i>, and <i>entFM</i>, respectively, in chromosomal or plasmid DNA. Overall, 37 isolates (90.2%) showed at least one enterotoxin gene. The emetic toxin gene, <i>ces</i>, was detected in the plasmid DNA of three isolates (7.3%). The antibiotic resistance of isolates was evaluated by the Kirby-Bauer disk diffusion procedure. All the isolates exhibited 100% susceptibility to gentamicin, 97% were susceptible to clindamycin, and 95% to chloramphenicol, imipenem, tetracycline, and vancomycin. The overall susceptibility average is 51%. However, 98% of the isolates were resistant to β-lactam antibiotics, 97.5% were resistant to sulfamethoxazole/trimethoprim, and 80% were resistant to rifampin. This study provides important information on <i>B. cereus</i> isolates from spacecraft assembly facilities for use in microbial monitoring programs of spacecraft.2023-01-01T00:00:00Z20232025-04-25T17:35:14.884Z2025-04-06T04:05:23.949ZS-EPMC106906123804502810.3389/fmicb.2023.1231726