Antimicrobial resistance of bacterial strains in patients undergoing orthodontic treatment with and without fixed appliances

Abstract

Objectives To identify microorganisms isolated from patients wearing fixed orthodontic appliances and to evaluate the resistance of isolated bacterial strains to different antimicrobials. Materials and Methods Seventeen healthy patients wearing a fixed orthodontic appliance (group 1) and six nonwearers (group 2, control group) were evaluated. The biofilm that formed around the orthodontic brackets was collected, and the samples were then plated in a chromogenic medium (chromIDT, bioMérieux). Colony-forming units (CFUs) were isolated and inoculated in blood-agar medium. Automated biochemical tests (VITEK 2, bioMérieux) were carried out to identify the genus and species of the microorganisms and the resistance provided by 43 drugs (37 antibacterial and 6 antifungal). Results The most prevalent microbial genera identified in group 1 were Streptococcus (24.0%), Staphylococcus (20.0%), Enterobacter (12.0%), Geobacillus (12.0%), and Candida (12.0%), and the most frequent species were Enterobacter cloacae complex (13.6%) and Staphylococcus hominis (13.6%). In group 2, the most prevalent genera were Streptococcus (57.1%), Staphylococcus (14.2%), Sphingomonas (14.2%), and Enterobacter (14.2%). With regard to antimicrobial resistance, 14 of 19 (74%) isolated bacterial strains were found to be resistant to at least 1 of the tested antimicrobials. Conclusions The findings of the present study suggest that patients undergoing orthodontic treatment with fixed appliances have a more complex biofilm with a higher level of bacterial resistance.

The effect of orthodontic appliances on the Oral Candida colonisation: a systematic review

“…From baseline to one month of ROA therapy, a significant increase (p < 0.001) in the number of Candida albicans counts was observed in saliva 20 and on the oral mucosa. 26 During the early stages of FOA, Hägg et al 14 found a significant Candida increase on the dorsum of the tongue (p < 0.001), but not in saliva and plaque samples. Arslan et al 15 reported an increase in the number of colony-forming units (CFU) was statistically significant (p < 0.001) both in saliva and on tooth surfaces.…”

“…The characteristics of the studies are presented in Table IV. Of the 16 included studies, all were prospective in nature and included four reports which described the changes in Candida in patients treated using a ROA 13,17,20,26 and nine studies which described those treated with FOA. 8,[14][15][16][21][22][23][24]27 Three studies analysed and compared treated and non-treated patients, two of which involved a ROA 17,18 and one used FOA 25 .…”

“…Two studies 20,26 described the short-term changes occurring during ROA treatment; eight studies 8,14,15,[21][22][23][24]27 analysed the effects related to FOA therapy. From baseline to one month of ROA therapy, a significant increase (p < 0.001) in the number of Candida albicans counts was observed in saliva 20 and on the oral mucosa.…”

“…Eleven studies described the changes in the frequency of the different candida strains during orthodontic treatment using a ROA [17][18][19]26 and FOA. [14][15][16]21,[23][24][25] Mahmoudabi et al 17…”

“…Arendorf et al 13 suggested that ROA may initiate a Candida carrier state by inducing a significant, although transient, increase in Candida colonisation, especially on the palate. According to several studies, an incremental change was found in the Candida counts during ROA therapy, from short 20,26 to a long-term period. 20 These results agree with previous studies confirming that ROA wear alters oral microbiological homeostasis due to the presence of new retentive surfaces, the ROA design, and the duration of ROA use, all of which favour bacterial adhesion and biofilm formation.…”