Goiter parenchyma, blood vessels and lymphatics contain Staphylococcus epidermidis - saprophyte or pathogen?

BackgroundGoiter in its various clinical and histopathological forms is accompanied by an inflammatory process requiring intensive therapy. The thyroid gland is an organ specifically exposed to the microbial environment due to its close location to the mouth microbiome. A number of bacterial phenotypes has been detected in the inflamed thyroid gland. A question raises as to whether bacteria have not already been present in the thyroid gland before the clinical symptoms of goiter became evident.\n\nAimTo answer the questions: a) do the goiter tissue structures contain bacteria, b) if so, which bacterial phenotypes can be identified, c) what are the genetic similarities of the thyroid and periodontal bacterial strains.\n\nMaterial and methodsStudies were carried out in 60 patients with the non-toxic multinodular goiter in 40 cases, toxic multinodular goiter in 10, single adenoma in 3, Hashimotos disease with nodular changes in 4 and recurrent thyroid disease in 3. Tissue fragments harvested during surgery were placed on Columbia blood agar base enriched with 5% defibrinated sheep blood. In this method bacteria present in the tissue slowly proliferate in their in vivo transferred to ex-vivo environment, crawl out and form the on-plate colonies. It enables detection of single bacteria usually difficult in a standard planktonic culture.\n\nResultsa) Coagulase-negative Staphylococci were shown growing on culture plates in above 50% of thyroid parenchyma, veins, arteries and adjacent lymphoid tissue specimens, b) tissue-originating colony-forming bacteria appeared on plates on day 3, but in some as late as after 12-21 days, c) all isolates were sensitive to the basic antibiotics, d) bacterial thyroid and oral DNA tests showed similarities indicating possibility of the oral origin, e) the on-plate time-prolonged cultures showed shrinking of the colonies and upon adding liquid medium formed the small variant colonies.\n\nConclusionsThyroid gland tissues contained in above 50% of specimens the coagulase-negative Staphylococci. Over 88% similarity of the genetic pattern of Staphylococcus epidermidis strain from tooth, oropharyngeal and thyroid tissues, estimated with PCR MP technique, suggested their periodontium origin.