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.

GAETTI-JARDIM Jr., E.; LANDUCCI, L. F.; ARAFAT, O. K. K.; RANIERI, R. V.; RAMOS, M. M. B.; CIESIELSKI, F. I. N.; SCHWEITZER, C. M. & OKAMOTO, A. C. Antimicrobial activity of six plant extracts from the Brazilian savanna on periodontal pathogens. Int. J. Odontostomat., 5(3):249-256, 2011. ABSTRACT: The extracts of plants from Brazilian savanna are currently used in popular medicine. This study evaluated the inhibitory activity of the alcoholic and aqueous extracts from savanna plants on periodontal bacteria. The minimal inhibitory concentrations were evaluated by the agar dilution method, using Wilkins-Chalgren agar. Antimicrobial activity of plants extracts on microbial biofilms was determined in microplates. Psidium cattleianum and Myracrodruon urundeuva extracts demonstrated significant inhibitory activity on all bacterial strains tested; alcoholic and aqueous extracts showed similar results. The extracts from these two species were able to inhibit both planktonic cells and microbial biofilm. KEY WORDS: anaerobic bacteria, plant extracts, antimicrobial agents, periodontitis.

Bovine periodontitis is a multifactorial disease primarily associated with a potentially pathogenic microbiota housed in the oral biofilm of animals. Biofilms are organized structures, in which the constituents coexist in symbiosis, already described as a predisposing factor to periodontitis in other species. The objective of the present study was to characterize the structure and chemical aspects of the bovine black pigmented supragingival biofilm using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively, and determine its relationship with bovine periodontitis. Eleven premolar teeth from different animals were evaluated; five non-pigmented samples and six samples with black pigmented biofilms were initially submitted to SEM, and three areas of these samples were selected for EDS. The structure of the pigmented biofilm was more complex and irregular because of a higher content of mineral elements. The semi-quantitative EDS data indicated an association of iron (p<0.014) and magnesium (p<0.001) with the occurrence of periodontitis, whereas carbon, phosphorus, calcium, manganese, sodium, and potassium were not associated with the disease. Carbon (p<0.039), manganese (p<0.007), and iron (p<0.015) were associated with pigmentation, whereas phosphorus, calcium, and magnesium were not associated with it. Spearman correlation test showed the relationships between calcium and phosphorus, and iron and silicon. The strong association of iron in the pigmented supragingival biofilm and with the occurrence of periodontitis suggests the presence of microorganisms that use this element in their metabolism and that are also associated with bovine periodontitis. This study suggests that the pigmented deposits in the crown of the teeth of cattle are an true biofilm with the deposition of iron, and it indicates that the presence of iron and magnesium in these formations may be involved in the metabolism of some microorganisms associated with the etiology of bovine periodontitis.

The human microbiome undergoes variation in the most diverse regions of our body, according to the conditions to which it is exposed, being of vital importance for human health. It presents several conditions that can promote the establishment of microorganisms and in imbalance favor the development of opportunistic pathogens, the knowledge of the distribution of these microorganisms in different organs and their biological role leads to a better understanding of their complex dynamics, improving the development of a new one forms of diagnosis and even treatment of certain pathologies. Among the most pathologies studied today, we can mention infections caused by fungi is one of the widely studied area. These microorganisms are becoming increasingly resistant to conventional treatments, increasing reports of resistance, especially the Candida species, which despite being present in the normal flora of the human organism have been causing several cases of contamination and infections, called candidosis. Due to the increased resistance to conventional antifungal treatments, it is necessary to develop strategies that can prevent and treat the spread of these microorganisms. For this, alternative studies with medicinal plants have been growing and expanding the understanding and applicability of new compounds with antimicrobial properties, since, for millennia, makind has used plants to treat various types of diseases and this traditional knowledge facilitates the search for research targets of natural components from plants, allowing scientific proof of these therapeutic effects. This work aims at a bibliographical survey of the applicabilities of the Phyllanthus niruri L. (Stone-breaking) plant, in the face of the challenges of science when developing new sources to combat resistant microorganisms.

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