RE: does TB grow out of formalin fixed tissue?
Vinnie, here is a review article on that
The viability of Mycobacterium
tuberculosis in formalin-fixed pulmonary autopsy tissue: review of the
literature and brief report.
Kappel TJ, Reinartz JJ, Schmid
JL, Holter JJ, Azar MM.
Department of Laboratory Medicine, University
of Minnesota Hospital, Minneapolis, USA.
Formalin is commonly thought to
decrease the risk of Mycobacterium tuberculosis infection. However, the true
disinfection efficacy of formalin for tissue infected with M tuberculosis is
unclear. We reviewed all pertinent literature from 1900 until the present
regarding the disinfection efficacy of formalin for tissue infected with M
tuberculosis. We also retrospectively cultured five cases of M tuberculosis from
formalin-fixed archival pulmonary tissue. All cultures from our archived tissue
were negative. The literature review revealed limited and contradictory
information concerning the viability of M tuberculosis in formalin-fixed human
tissue. There are no studies which specifically address the viability of M
tuberculosis in tissue exclusively fixed in 10% buffered formalin. The
disinfection efficacy of formalin for tuberculosis infected tissue remains
unclear. Larger, prospective studies using current methodologies are needed to
establish guidelines to ensure the safety for those handling infected, fixed
PMID: 8958312 [PubMed - indexed for MEDLINE]
one of our pathologists indicated to me that she is certain that TB has
been grown from formalin fixed tissue. She also believes this is true for HIV.
This information was offered to contradict a statement I made to a resident
that formalin fixation neutralizes blood borne pathogens.
I'd appreciate hearing from anyone who can speak to this issue
( efficacy of formalin to neutralize infectious organisms,
especifically on the infectious potential of TB, HIV and Hep C) with
Of course there is always the possibility that tissues had not been
adequately exposed to formalin which permitted some organisms to escape its
effects and then grow in culture, as for example, when large organs are
dropped in formalin without breadloafing.
appreciate your thoughts
Vinnie Della Speranza
Manager for Anatomic Pathology
Medical University of South Carolina
165 Ashley Avenue
Charleston, SC 29425
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