Search for bacterial biofilms in the chronic anal fissure (descriptive study with in-depth visualization)

AIM: to reveal biofilms in chronic anal fissure (CAF) bacterial composition. PATIENTS AND METHODS: patient A., 40 years old, with chronic posterior and anterior anal fissures with sphincter spasm underwent a lateral subcutaneous sphincterotomy with excision of the CAFs. Before the operation swabs were taken from fissures for microbiology. Removed specimens were placed in fixing solutions. Microbiological studies including 16S rRNA gene sequencing and MALDI-ToF mass spectrometry of isolated cultures were carried out to assess the bacterial composition of CAFs. Microscopic studies which included scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to search for the biofilm location of microorganisms. Conclusions about the presence of biofilms were made during the comparison of photographs with reliable images described in the literature. RESULTS: a wide variety of bacteria (56 genera) was detected in the tissues forming the CAF based on sequencing of 16S rRNA genes; swab's mass spectrometry revealed only E. coli and P. anaerobius in significant concentrations. Using SEM on one of the sections of the excised CAF were found biofilms containing bacterial cells immersed in an extracellular matrix (which size was within the limits of 2 microns); similar structures weren't detected outside the CAF. On TEM an accumulation of bacterial cells, surrounded by an extracellular polymer matrix, what was interpreted as a biofilm of gram-negative bacteria, was identified. After 7 months, the patient retained a non-healing postoperative wound in the area of the previously excised posterior fissure. After repeated sowing, E. coli and S. gallolyticus were obtained in significant concentrations. Excision of the scarred edges of the wound and the prescribed conservative treatment allowed the wound to epithelize within 3 weeks. CONCLUSION: the results show that microbial biofilms can be localized in the CAF. Further researches are needed for reliable conclusions about biofilm organization in CAF and their effect on pathological and reparative processes.