Resistance to tetracycline and β-lactams and distribution of resistance markers in enteric microorganisms and pseudomonads isolated from the oral cavity

Abstract

This study evaluated the occurrence of enteric bacteria and pseudomonads resistant to tetracycline and β-lactams in the oral cavity of patients exhibiting gingivitis (n=89), periodontitis (n=79), periodontally healthy (n=50) and wearing complete dentures (n=41). Microbial identification and presence of resistance markers associated with the production of β-lactamases and tetracycline resistance were performed by using biochemical tests and PCR. Susceptibility tests were carried out in 201 isolates of enteric cocci and rods. Resistance to ampicillin, amoxicillin/clavulanic acid, imipenem, meropenem and tetracycline was detected in 57.4%, 34.6%, 2.4%, 1.9% and 36.5% of the isolates, respectively. β-lactamase production was observed in 41.2% of tested microorganisms, while the most commonly found β-lactamase genetic determinant was gene blaTEM. Tetracycline resistance was disseminated and a wide scope of tet genes were detected in all studied microbial genus.

Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

“…The biofilms of P. aeruginosa should be characterized as having thick exopolysacharide "slime" layers, and researchers have found that production of the exopolymer alginate is unregulated in biofilm grown P. aeruginosa. 10,15 The significant difference Figure 5. . Survival of multibacterial biofilms after photodynamic inactivation with phthaloicyanine photosensitizers.…”

“…The failures are related to the presence of large percentage aerobic and facultative anaerobic bacteria such as Enterococcus faecalis, Staphylococcus aureus and more rare Pseudomonas aeruginosa and members of family Enterobacteriaceae and Candida albicans. [9][10][11] The eradication of the microbial biofilm by a conventional antibiotic therapy is exclusively difficult or almost impossible due the much higher resistance level of the bacteria's. That is caused by the barrier effect of the builded exopolysaccharide protective matrix, and more importantly by heterogeneous genetic and metabolic adaptations mechanisms of the cells to new variant of growth that transforms the planktonic lifestyle into a sessile form.…”

“…This leads to suggestion that they are secondary invaders that contribute to the progression of the destruction. 4,5,7,10 Therefore the more sensitive to antibiotics microbial participants in infection are superimposed the more resistant bacterial representatives. Ones of the most frequent agents of root canal infection, E. faecalis is resistant to the most of the intracanal medicaments, as such as all of the cephalosporins and some of the other of antibiotics.…”

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

“…The dissemination of gram-negative bacteria with acquired antimicrobial drugs resistance is becoming a global problem. The propagation and dissemination of these microorganisms have already been confirmed 11,25 .…”

“…The production of these hydrolytic enzymes seems to be the major mechanism of resistance to β-lactams, excluding most pseudomonads, in which β-lactamases were not detected. On the other hand, resistance to tetracycline was widely disseminated in the microbial enteric rods, and many of tested microorganisms were resistant 25 .…”