ODONTOLOGÍA VITAL P. 5
Revista Odontología Vital
No. 37, Vol 1, 3-7 2022 I ISSN:2215-5740
Antibiotic resistance and oral cavity
Oral microbiota forms an
ecosystem that includes a wide
diversity of symbiotic, commensal,
and opportunistic pathogenic
microorganisms. The balance between
these is essential to maintain oral
and systemic health, that means that
around 700 species must maintain
a balanced habitat, or else, allow the
predominance of infectious entities.
(Moraes, et al. 2015)
It has been found that the structural
stability of the biofilm, as well as the
close proximity between bacterial
cells, constitutes an ideal medium
for horizontal gene transfer, and in
turn, could lead to the transmission
of characteristics such as bacterial
antibiotic resistance. (Roberts &
Mullany, 2010) This mechanism allows
the acquisition of DNA available in the
external environment and generates a
transcendental impact on the plasticity
of the genome, the adaptation and
evolution of bacteria. (Quiros, 2018)
In addition to the presence of
microorganisms, the oral cavity has
a matrix of extracellular polymeric
substances (EPS) secreted by the
bacteria of the microflora. This
matrix gives the biofilm its physical
characteristics, including adhesion,
mechanical strength, and bacterial
resistance.
EPS are made up of carbohydrates,
proteins, lipids, and nucleic acids.
(Jain, et al. 2013). In a mature biofilm,
this matrix surrounding bacterial cells
can limit the entry of antibiotics to the
vicinity of bacteria located in deeper
areas. (Mah & O’Toole, 2001)
It should be noted that bacteria that
have antimicrobial resistance, develop
an interesting phenomenon: they
are capable of releasing compounds
that provide antimicrobial resistance
within the surrounding environment.
Therefore, a diffusion of these occur
within the biofilm and a transitory zone
of high resistance is generated. (Roberts
& Mullany, 2010)
For example, oral streptococci are found
within the normal oral microflora, and
can be part of the ecosystem without
inducing pathologies. However, they
can act as genetic reserves in the
transfer of resistance genes for bacteria
that enter the oral cavity transiently.
A possible association has even been
observed between the transfer of
antibiotic resistance from streptococci
that are normally present in the
mouth to Streptococcus pneumoniae.
(Barrientos, et al. 2015)
Furthermore, some in vitro
investigations have reported the
phenotypic adaptation of early
biofilm colonizers when antiseptics
such as Chlorhexidine Gluconate and
Cetylpyridine Chloride are used in
multiple exposures at subinhibitory
concentrations. (Auer, et al. 2022)
Barrientos et al. (2015) urge the dental
professionals to realize that, by having
the possibility of prescribing antibiotics
within the daily consultation, they
become an essential part of the
global efforts to control and reduce
antimicrobial resistance.
Buonavoglia et al. (2021) offer some
basic suggestions on the use of
antibiotic therapy in dentistry:
- Dentists should use antibiotics
only in specific situations and