title: Should we care about transmission of infectious bacterial agents through serum handling?
abstract: Immunological assays are valuable diagnostic tools to detect infections due to most of bacterial microorganisms. However, the question is how much safe are the common serum samples used as sources of antibodies in these assays? Here, we experimentally followed the issue. 10-fold serial dilutions of two Gram-positive, Staphylococcus aureus and Bacillus cereus, and one Gram-negative bacteria, Escherichia coli, were prepared and spiked into freshly taken blood samples of human and four animal species including sheep, goat, cattle, and horse. After blood clotting, serum samples were examined by colony count method before and after a centrifugation step followed by an observation with a scanning electron microscope. No bacteria grew from both centrifuged and non-centrifuged serum samples contained at least 7.5 × 102, 7.5 × 105, and 7.5 × 105CFU/ml of S. aureus, B. cereus, and E. coli, respectively. Moreover, routine centrifugation criteria did not show any significant effect on decrease of bacterial cells in sera. The results suggest that we can handle serum samples of apparently healthy humans and animal species without deep concern for possibility of transmission of infectious bacterial agents. However, this supposition should not completely be excluded.
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran. Electronic address: mahmoodi_pezhman@yahoo.com.
authors.forename: Pezhman
authors.initials: P
authors.lastname: Mahmoodi
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Abdolmajid
authors.initials: A
authors.lastname: Mohammadzadeh
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Shadi
authors.initials: S
authors.lastname: Baniardalani
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Nourian
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Sadeghi-Nasab
authors.affiliation: Center for Electron Microscopy, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khaninour
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000254:growth & development; D001424:Bacterial Infections / Q000097:blood* / Q000635:transmission*; D058491:Bacterial Load; D058731:Blood Safety / Q000379:methods / Q000592:standards; D002498:Centrifugation; D015169:Colony Count, Microbial; D004866:Equipment Contamination; D004926:Escherichia coli / Q000254:growth & development; D006801:Humans; D044967:Serum / Q000382:microbiology*; D013048:Specimen Handling / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D013211:Staphylococcus aureus / Q000254:growth & development
keywords: Infectious bacterial agent; Serum; Transmission