title: The cultivable microbiota of primary and secondary infected root canals, their susceptibility to antibiotics and association with the signs and symptoms of infection.
abstract: OBJECTIVE
  To examine the presence of microbial species in primary and secondary infections and identify the signs and symptoms associated with them.
  
  
  METHODS
  A total number of 37 root canals from 33 patients undergoing root canal treatment were selected. Samples were taken using a sterile paper point following chemomechanical canal instrumentation. Microbiological identification was performed by macromorphological, micromorphological and commercial biochemical tests (ATB system). The antibiotic susceptibility profile of isolated Enterococcus, Streptococcus and Propionibacterium spp. was evaluated.
  
  
  RESULTS
  A total number of 54 species were isolated. The most common was E. faecalis followed by Propionibacterium acnes and Streptococcus spp. Five multidrug-resistant enterococcal strains were isolated. However, resistance to linezolid or glycopeptides was not found. Radiolucency was observed significantly more often in symptomatic infections (P = 0.0061) caused by Actinomyces spp. than in asymptomatic ones.
  
  
  CONCLUSIONS
  Enterococci and streptococci were the most commonly isolated bacteria from root canals. The resistance of enterococci to many antimicrobials may pose a problem in their eradication.
authors.affiliation: Department of Microbiology and Medical Laboratory Immunology, Medical University of Lodz, Lodz, Poland.
authors.forename: M E
authors.initials: ME
authors.lastname: Łysakowska
authors.affiliation: Medical Diagnostic Laboratory Center, Polish Mother's Memory Institute, Medical University of Lodz, Lodz, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Ciebiada-Adamiec
authors.affiliation: Department of Environmental Biology, Medical University of Lodz, Lodz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Sienkiewicz
authors.affiliation: Department of General Dentistry, Medical University of Lodz, Lodz, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Sokołowski
authors.affiliation: Department of General Dentistry, Medical University of Lodz, Lodz, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Banaszek
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003786:Dental Pulp Cavity / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification; D013293:Enterococcus faecalis; D006801:Humans; D064307:Microbiota; D012390:Root Canal Therapy; D013291:Streptococcus / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents
keywords: bacterial diversity; endodontic treatment; enterococci; resistance