The human body provides habitat for a diversity of bacterial species that are part of the normal human microbiota. Identification of various members of the normal microbiota to the species level requires a combination of biological staining procedures, biochemical tests, and molecular techniques. In this experiment, ten bacterial isolates originating from the hands of nine students and one faculty member at USC Salkehatchie were identified. Classification to a general taxonomic group was accomplished with standard staining and biochemical tests. Sequences for the 16S ribosomal RNA section of DNA for each isolate were analyzed with BLAST to generate a list of potential species identifications. Species associated with confidence levels greater than 98% were considered positive identifications. The samples were then analyzed using Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). Five isolates were identified as Bacillus megaterium (2 isolates), Bacillus thuringiensis, Paenibacillus alvei, and Micrococcus luteus. Four isolates were identified as Bacillus and Brevibacterium species. One isolate had conflicting identifications based on molecular and MALDI-TOF MS and is only listed as a Bacillus species. In addition to contributing to the study of the human normal microbiota, the diagnostic properties and identities of each isolate will be incorporated into a laboratory resource used by microbiology students at USC Salkehatchie.
Rauch, Leisa M.; Golonka, Annette M.; and Kilpatrick, Eran S.
"Identification of Bacterial Isolates Originating from the Human Hand,"
Journal of the South Carolina Academy of Science: Vol. 17:
2, Article 6.
Available at: https://scholarcommons.sc.edu/jscas/vol17/iss2/6