Proportion of antibiotic resistance in subgingival plaque samples from Mexican subjects.
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.
Almaguer-Flores
Argelia
A
Laboratory of Molecular Genetics, School of Dentistry, National University of Mexico (UNAM) Mexico city, Mexico.
Moreno-Borjas
Jazmin-Yunuen
JY
Salgado-Martinez
Araceli
A
Sanchez-Reyes
Marco-Antonio
MA
Alcantara-Maruri
Eulalio
E
Ximenez-Fyvie
Laurie-Ann
LA
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
D000900:Anti-Bacterial Agents; D000658:Amoxicillin; D004318:Doxycycline