title: Proportion of antibiotic resistance in subgingival plaque samples from Mexican subjects.
abstract: OBJECTIVE
  To determine the proportion of bacteria resistant to amoxicillin and doxycycline in subgingival plaque samples from Mexican subjects.
  
  
  METHODS
  Two subgingival plaque samples were taken from 20 Mexican subjects. Samples were dispersed, diluted and plated on non-antibiotic agar plates and on plates containing 0.5, 1, 2, 4, 8 and 16 microg/ml of either amoxicillin or doxycycline. The proportion of resistant bacteria was calculated based on the total number of colony-forming units present in the non-antibiotic containing plates.
  
  
  RESULTS
  On average, 0.4-13.4% and 0.9-20.4% of the total cultivable subgingival microbiota was resistant to the concentrations tested of amoxicillin and doxycycline, respectively. The differences between antibiotics were statistically significant for the 0.5, 2 and 4 mug/ml concentrations (p < 0.05, Wilcoxon's test).
  
  
  CONCLUSIONS
  Our findings revealed that a relatively small proportion of the total cultivable subgingival microbiota from Mexican subjects was resistant to amoxicillin and doxycycline.
authors.affiliation: Laboratory of Molecular Genetics, School of Dentistry, National University of Mexico (UNAM) Mexico city, Mexico.
authors.forename: Argelia
authors.initials: A
authors.lastname: Almaguer-Flores
authors.forename: Jazmin-Yunuen
authors.initials: JY
authors.lastname: Moreno-Borjas
authors.forename: Araceli
authors.initials: A
authors.lastname: Salgado-Martinez
authors.forename: Marco-Antonio
authors.initials: MA
authors.lastname: Sanchez-Reyes
authors.forename: Eulalio
authors.initials: E
authors.lastname: Alcantara-Maruri
authors.forename: Laurie-Ann
authors.initials: LA
authors.lastname: Ximenez-Fyvie
mesh_terms: D000328:Adult; D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000145:classification* / Q000187:drug effects; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology*; D004318:Doxycycline / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects; D006801:Humans; D008297:Male; D008800:Mexico; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010403:Penicillin Resistance; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents; D000658:Amoxicillin; D004318:Doxycycline