International Journal of Medicine and Medical Sciences Vol 1(6) pp. 267-271, June, 2009 Available online http://www.academicjournals.org/ijmms ©2009 Academic Journals Full Length Research paper Biofilm formation by Mycoplasma fermentans on intrauterine devices Antonio Rivera 1* , Lilia Cedillo 1 , Silvia Giono 2 and Nadia Rodriguez 3 1 Microbiological Research Center, Benemérita Universidad Autónoma de Puebla. México. 2 Bacteriology Laboratory, Instituto Politécnico Nacional, México, D.F. 3 Tropical Medicine Institute Pedro Kouri, Habana-Cuba. Accepted 03 June, 2009 Microbial biofilm are communities of sessile microorganisms formed by cells that are attached irreversibly to a substratum or interface or to each other and embedded in hydrated matrix of extracellular polymeric substances. Bacterial biofilm formation on intrauterine devices is a very important event in the pathogenesis and evolution of infections associated with the use of these medical devices. Mycoplasmas are typical surface parasites colonizing the mucous membranes of animals and man. Efficient adherence mechanisms are therefore a prerequisite for survival and, in some species, for pathogenicity. The purpose of this study was to examine biofilm formation by Mycoplasma fermentans on intrauterine devices. Intrauterine devices were placed in M. fermentans cultures during 72 h. Mycoplasmas were analyzed for biofilm formation and cell counts compared for both biofilm and planktonic cells. The examination was carried with stereoscopic and scanning electron microscope. Crystal violet staining and scanning electron microscopic analysis of intrauterine devices indicated that M. fermentans formed a biofilm. This study might allow for clearer understanding of the rate of biofilm formation and the importance of different materials, contaminating organisms, and treatments which could control the process. Key words: Adherence, biofilm, Mycoplasma fermentans, intrauterine devices. INTRODUCTION Mycoplasmas are a heterogeneous group of the smallest organisms capable of self-replication. Some mycopla- smas cause respiratory or urogenital diseases in human, but others chronically colonize our respiratory and uro- genital tracts without apparent clinical significance. In this respect, wall-free mycoplasmas are among the few pro- karyotes that can grow in close interaction with mamma- lian cells, often silently for a long period of time. How- ever, prolonged interactions with mycoplasmas with see- mingly low virulence could, through a gradual and pro- gressive course, significantly affect many biological pro- perties of mammalian cells (Loo et al., 1991; Taylor-Ro- binson, 1989). Because mycoplasmas have an extremely small geno- me (0.58-2.20 Mb compared with the 4.64 Mb of Escheri- chia coli), these organisms have limited metabolic op- tions for replication and survival. These micro-organisms *Corresponding author. E-mail: jart70@yahoo.com. Tel. (011 52) 222 2 29 55 00, Ext. 2545. have evolved molecular mechanisms needed to deal with the host immune response and the transfer and coloniza- tion in a new host (Rottem, 2003). Many mycoplasmas depended on adhesion to host tissues for colonization and infection. In the mycoplasmas the adherence is the major virulence factor, and adherence-deficient mutants are avirulent. These organisms exhibit the typical poly- morphism of mycoplasmas, with the most common flask and filamentous shaped. Cytadherence of these orga- nisms to cells in the respiratory or urogenital epithelium is an initial essential step in tissue colonization and subseq- uent disease pathogenesis (Baseman and Tully, 1997; Razin and Jacobs, 1992). Because these surfaces are sometimes providing quite inhospitable environments, the mycoplasmas had to develop very efficient mechanisms to adherence to the various cells and substrates. Mycoplasma fermentans is an infectious agent of the human urogenital and pulmonary systems (Nicol and Ed- ward, 1953; Taylor-Robinson, 1995). Because it has been shown to be associated with lesions in the kidneys of human immunodeficiency virus-positive patients (Bau- er et al, 1991) and causes fulminating disease in monkey