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AIM: Aerosols released from the oral cavity help spread the SARS-CoV-2 virus. The use of a mouthwash formulated with an antiviral agent could reduce the viral load in saliva, helping to lower the spread of the virus. The aim of this study was to assess the efficacy of a mouthwash with 0.07% cetylpyridinium chloride (CPC) to reduce the viral load in the saliva of Coronavirus disease 2019 (COVID-19) patients. MATERIALS AND METHODS: In this multi-centre, single-blind, randomized, parallel group clinical trial, 80 COVID-19 patients were enrolled and randomized to two groups, namely test (n = 40) and placebo (n = 40). Saliva samples were collected at baseline and 2 h after rinsing. The samples were analysed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and an enzyme-linked immunosorbent assay test specific for the nucleocapsid (N) protein of SARS-CoV-2. RESULTS: With RT-qPCR, no significant differences were observed between the placebo group and the test group. However, 2 h after a single rinse, N protein concentration in saliva was significantly higher in the test group, indicating an increase in lysed virus. CONCLUSIONS: The use of 0.07% CPC mouthwash induced a significant increase in N protein detection in the saliva of COVID-19 patients. Lysis of the virus in the mouth could help reduce the transmission of SARS-CoV-2. However, more studies are required to prove this.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/prevenção & controle , Cetilpiridínio/uso terapêutico , Antissépticos Bucais/uso terapêutico , Carga Viral , Método Simples-CegoRESUMO
AIM: To investigate microbial profiles in placentas from a population of East African mothers with and without adverse pregnancy outcomes and with regard to their periodontal status. MATERIAL AND METHODS: Thirty-six placentas from pregnant women from Tanzania were classified into three groups according to both pregnancy outcome and the mother's periodontal health. The microbial composition in each group was then compared using 16S rRNA metagenomics. Additionally, placenta specimens were analyzed histologically for chorioamnionitis by a single pathologist blinded to the clinical data. RESULTS: The greatest differences were observed in the group of mothers with periodontitis. The microbial load was low in all three groups of mothers. Periodontitis had a notable influence on the structure of the placental microbiota. Three phyla and 44 genera were associated with periodontitis, whereas only the Tenericutes phylum was associated with the adverse pregnancy variable. Streptococcaceae and Mycoplasmataceae families were associated with both periodontitis and adverse pregnancy outcomes. Finally, although the differences for chorioamnionitis were not significant, this intra-amniotic infection was more frequent in the placentas from mothers with periodontitis. CONCLUSIONS: Our findings suggest that bacteria from the oral cavity may involve the feto-placental unit, and that periodontitis may be a modulating factor of the microbial community present in this niche.
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Corioamnionite , Periodontite , Gravidez , Feminino , Humanos , Resultado da Gravidez , Placenta/microbiologia , Tanzânia/epidemiologia , Mães , RNA Ribossômico 16S/genética , Periodontite/microbiologiaRESUMO
OBJECTIVE: Toothbrushes are colonized by microorganisms, implying a risk of infection. That risk can be reduced by decreasing the microbial contamination of the filaments. Therefore, this study aimed to determine the antiseptic efficacy of a 0.05% chlorhexidine + 0.05% cetylpyridinium chloride mouthwash on toothbrushes. METHODS: A total of twelve toothbrushes used three times/day for 14 days by orally and systemically healthy people were randomly split into two groups, and their heads were immersed for 2 h in PBS (control) or Perio·Aid Active Control (treatment). The microorganisms were recovered, and their number was calculated by culture, quantitative PCR, and viability PCR. Statistical differences were first assessed with a two-way mixed ANOVA and subsequently with Student's t-test. RESULTS: The results showed no statistical differences in the total number of cells for the treatment (mean ± CI95% of 7.27 ± 1.09 log10 bacteria/ml) and the control (7.62 ± 0.64 log10 bacteria/ml) groups, but a significantly lower number of live cells in the treatment group (4.58 ± 0.61 log10 viable bacteria/ml and 2.15 ± 1.42 log10 cfu/ml) than in the control group (6.49 ± 1.39 log10 viable bacteria/ml and 5.04 ± 0.93 log10 cfu/ml). CONCLUSIONS: Based on our findings, sanitization of toothbrushes with this mouthwash reduces the number of live microorganisms adhered to the filaments. Such decrease of the bacterial load could include bacteria from the oral cavity, from the environment, and from nearby toothbrushes since the quantification was not limited to any bacterial taxon.
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Clorexidina , Antissépticos Bucais , Humanos , Clorexidina/uso terapêutico , Antissépticos Bucais/uso terapêutico , Cetilpiridínio/uso terapêutico , Descontaminação/métodos , Imersão , BactériasRESUMO
OBJECTIVES: The aim of this study was to analyze the distribution of ß-lactamase genes and the multidrug resistance profiles in ß-lactam-resistant subgingival bacteria from patients with periodontitis. MATERIALS AND METHODS: Subgingival samples were obtained from 130 Spanish patients with generalized periodontitis stage III or IV. Samples were grown on agar plates with amoxicillin or cefotaxime and incubated in anaerobic and microaerophilic conditions. Isolates were identified to the species level by the sequencing of their 16S rRNA gene. A screening for the following ß-lactamase genes was performed by the polymerase chain reaction (PCR) technique: blaTEM, blaSHV, blaCTX-M, blaCfxA, blaCepA, blaCblA, and blaampC. Additionally, multidrug resistance to tetracycline, chloramphenicol, streptomycin, erythromycin, and kanamycin was assessed, growing the isolates on agar plates with breakpoint concentrations of each antimicrobial. RESULTS: ß-lactam-resistant isolates were found in 83% of the patients. Seven hundred and thirty-seven isolates from 35 different genera were obtained, with Prevotella and Streptococcus being the most identified genera. blaCfxA was the gene most detected, being observed in 24.8% of the isolates, followed by blaTEM (12.9%). Most of the isolates (81.3%) were multidrug-resistant. CONCLUSIONS: This study shows that ß-lactam resistance is widespread among Spanish patients with periodontitis. Furthermore, it suggests that the subgingival commensal microbiota might be a reservoir of multidrug resistance and ß-lactamase genes. CLINICAL RELEVANCE: Most of the samples yielded ß-lactam-resistant isolates, and 4 different groups of bla genes were detected among the isolates. Most of the isolates were also multidrug-resistant. The results show that, although ß-lactams may still be effective, their future might be hindered by the presence of ß-lactam-resistant bacteria and the presence of transferable bla genes.
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Microbiota , Periodontite , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Microbiota/genética , Periodontite/tratamento farmacológico , RNA Ribossômico 16S/genética , Resistência beta-Lactâmica , beta-LactamasRESUMO
OBJECTIVES: To study oral Prevotella spp. isolated from patients with chronic periodontitis, to determine their susceptibility to azithromycin and erythromycin and to screen the presence of macrolide resistance genes therein. MATERIAL AND METHODS: Isolates with a Prevotella-like morphology were obtained from subgingival samples of 52 patients with chronic periodontitis. Each isolate was identified to the species level by sequencing of the 16S rRNA gene. In 100 Prevotella spp. isolates, azithromycin and erythromycin susceptibility was determined using the E test method, and the screening of erm(A), erm(B), erm(C), erm(F), erm(G), erm(Q) and mef(A) genes was done by PCR. RESULTS: Prevotella intermedia and Prevotella nigrescens were the most identified species (33% each). Minimum inhibitory concentrations (MICs) ranges for both antibiotics were 0.016/0.032 to >256 µg/ml. MIC50 values for azithromycin and erythromycin were 1.5 and 1 µg/ml, respectively, and MIC90 values were >256 µg/ml for both antibiotics. Nineteen per cent of the isolates carried erm(B), and 51% carried erm(F). CONCLUSIONS: The MIC values found were high compared to previous studies. erm(F) was greatly prevalent, and we describe for the first time the erm(B) gene in Prevotella spp. The presence of either of the genes seems to be associated with a higher degree of resistance to azithromycin and erythromycin.
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Antibacterianos/farmacologia , Azitromicina/farmacologia , Periodontite Crônica/microbiologia , Farmacorresistência Bacteriana/genética , Metiltransferases/genética , Prevotella/efeitos dos fármacos , Prevotella/genética , Proteínas de Bactérias/genética , Eritromicina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-IdadeRESUMO
Aviation emits pollutants that affect the climate, including CO2 and NO x, NO x indirectly so, through the formation of tropospheric ozone and reduction of ambient methane. To improve the fuel performance of engines, combustor temperatures and pressures often increase, increasing NO x emissions. Conversely, combustor modifications to reduce NO x may increase CO2. Hence, a technology trade-off exists, which also translates to a trade-off between short-lived climate forcers and a long-lived greenhouse gas, CO2. Moreover, the NO x-O3-CH4 system responds in a nonlinear manner, according to both aviation emissions and background NO x. A simple climate model was modified to incorporate nonlinearities parametrized from a complex chemistry model. Case studies showed that for a scenario of a 20% reduction in NO x emissions the consequential CO2 penalty of 2% actually increased the total radiative forcing (RF). For a 2% fuel penalty, NO x emissions needed to be reduced by >43% to realize an overall benefit. Conversely, to ensure that the fuel penalty for a 20% NO x emission reduction did not increase overall forcing, a 0.5% increase in CO2 was found to be the "break even" point. The time scales of the climate effects of NO x and CO2 are quite different, necessitating careful analysis of proposed emissions trade-offs.
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Aeronaves , Ozônio , Clima , MetanoRESUMO
OBJECTIVE: The objective of this study was to compare the periodontopathogen prevalence and tetracycline resistance genes in Dominican patients with different periodontal conditions. METHODS: Seventy-seven samples were collected from healthy, gingivitis, chronic (CP) and aggressive (AgP) periodontitis patients. Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Parvimonas micra, Eikenella corrodens and Dialister pneumosintes and 11 resistance genes were studied by PCR. P. gingivalis fimA genotype was determined. RESULTS: In healthy patients, P. micra and P. intermedia were the most and least frequently detected, respectively. T. forsythia and E. corrodens appeared in 100% of gingivitis patients. Red complex, D. pneumosintes and E. corrodens were significantly more prevalent in CP compared to healthy patients. F. nucleatum and T. denticola were detected more frequently in AgP. A. actinomycetemcomitans was the most rarely observed in all groups. The fimA II genotype was the most prevalent in periodontitis patients. Seven tetracycline-resistant genes were detected. tet(Q), tet(32) and tet(W) showed the greatest prevalence. tet(32) was significantly more prevalent in CP than in healthy patients. CONCLUSIONS: Red complex bacteria and D. pneumosintes were significantly the most prevalent species among periodontitis patients. T. forsythia was the most frequently detected in this population. To our knowledge, this is the first study describing the tet(32) gene in subgingival biofilm from healthy and periodontally diseased subjects. CLINICAL RELEVANCE: This study contributes to the knowledge on the subgingival microbiota and its resistance genes of a scarcely studied world region. Knowing the prevalence of resistance genes could impact on their clinical prescription and could raise awareness to the appropriate use of antibiotics.
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Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Biofilmes , Periodontite/tratamento farmacológico , Periodontite/genética , Periodontite/microbiologia , Resistência a Tetraciclina/genética , Adulto , Idoso , Infecções Bacterianas/epidemiologia , Estudos de Casos e Controles , República Dominicana/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Microbiota , Pessoa de Meia-Idade , Periodontite/epidemiologia , Reação em Cadeia da Polimerase , PrevalênciaRESUMO
BACKGROUND: The oral cavity is the site of entry and replication for many respiratory viruses. Furthermore, it is the source of droplets and aerosols that facilitate viral transmission. It is thought that appropriate oral hygiene that alters viral infectivity might reduce the spread of respiratory viruses and contribute to infection control. MATERIALS AND METHODS: Here, we analyzed the antiviral activity of cetylpyridinium chloride (CPC), chlorhexidine (CHX), and three commercial CPC and CHX-containing mouthwash preparations against the Influenza A virus and the Respiratory syncytial virus. To do so the aforementioned compounds and preparations were incubated with the Influenza A virus or with the Respiratory syncytial virus. Next, we analyzed the viability of the treated viral particles. RESULTS: Our results indicate that CPC and CHX decrease the infectivity of both the Influenza A virus and the Respiratory Syncytial virus in vitro between 90 and 99.9% depending on the concentration. Likewise, CPC and CHX-containing mouthwash preparations were up to 99.99% effective in decreasing the viral viability of both the Influenza A virus and the Respiratory syncytial virus in vitro. CONCLUSION: The use of a mouthwash containing CPC or CHX alone or in combination might represent a cost-effective measure to limit infection and spread of enveloped respiratory viruses infecting the oral cavity, aiding in reducing viral transmission. Our findings may stimulate future clinical studies to evaluate the effects of CPC and CHX in reducing viral respiratory transmissions.
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Anti-Infecciosos Locais , Vírus da Influenza A , Clorexidina , Antissépticos Bucais , Cetilpiridínio/farmacologia , Vírus Sinciciais Respiratórios , Antivirais/farmacologiaRESUMO
OBJECTIVE: The goal of this study was to determine the genetic variability of the fimA gene in Porphyromonas gingivalis isolates from Spanish patients. STUDY DESIGN: Pooled subgingival samples were taken, processed and cultured in non-selective blood agar medium. Pure cultures of one to six isolates per patient were obtained and PCR and PCR-RFLP were used for fimbrillin gene (fimA) type determination of the extracted genomic (DNA). RESULTS: Two hundred and twenty four Porphyromonas gingivalis isolates from 65 patients were analyzed consisting of 15 non-periodontitis patients (66 isolates) and 50 with periodontitis (158 isolates). Genotype II was the most prevalent (50.9%), while the other types of fimbriae did not exceed fifteen percent of prevalence. Isolates with types II and IV of fimbriae were significantly more prevalent in periodontitis patients than isolates with genotype I. Co-infection was observed in 17.65% of the patients analyzed. CONCLUSION: The results suggest that in this population Porphyromonas gingivalis with type II of fimbriae are significantly more predominant in periodontitis patients than genotype I.
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Infecções por Bacteroidaceae , Proteínas de Fímbrias/genética , Periodontite/microbiologia , Porphyromonas gingivalis/genética , Humanos , Porphyromonas gingivalis/isolamento & purificaçãoRESUMO
OBJECTIVES: The aim of this investigation was to evaluate whether the adenosine triphosphate (ATP) bioluminescence method is an appropriate tool to assess the efficacy of antiseptic mouthrinses in terms of quantitative reductions of total viable microbial counts in mixed biofilm populations in vitro. STUDY DESIGN: Three mouthrinses, containing respectively, chlorhexidine and cetylpyridinium chloride (CHX/CPC), essential oils (EO) and amine fluoride/stannous fluoride (AFSF), as well as Phosphate Buffered Saline (PBS) used as control, were tested in an in vitro static biofilm model by ATP bioluminescence and compared to culture method. Biofilms were grown on saliva-coated hydroxyapatite disks for 72 hours and then exposed for 1 minute to the mouthrinse or control by immersion. The antibacterial effect of the rinses was tested by analysis of variance. The reliability of the ATP bioluminescence method was assessed by calculating the Pearson correlation coefficients when compared to the viable cell counts obtained by culture. RESULTS: Using ATP bioluminescence, the antimicrobial activity of the tested mouthrinses was demonstrated when compared to the PBS control. The ATP bioluminescence values were significantly correlated (0.769, p<0.001) to the viable cell counts. CHX/CPC and AFSF showed similar antimicrobial activity, although AFSF had a less homogeneous effect, being both more effective than the EO rinse. CONCLUSION: ATP bioluminescence viability testing may be considered a useful tool to assess the in vitro efficacy of antibacterial compounds. In the proposed model, CHX/CPC and AFSF containing mouthrinses demonstrated superior antimicrobial activity, as compared to EO rinses, in a multispecies biofilm model.
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Anti-Infecciosos Locais/farmacologia , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Medições Luminescentes , Antissépticos Bucais/farmacologia , Trifosfato de AdenosinaRESUMO
There is scarce knowledge regarding the antimicrobial resistance profile of F. alocis. Therefore, the objective of this research was to assess antimicrobial resistance in recently obtained F. alocis clinical isolates and to identify the presence of antimicrobial resistance genes. Isolates were obtained from patients with periodontal or peri-implant diseases and confirmed by sequencing their 16S rRNA gene. Confirmed isolates had their genome sequenced by whole genome sequencing and their phenotypical resistance to nine antibiotics (amoxicillin clavulanate, amoxicillin, azithromycin, clindamycin, ciprofloxacin, doxycycline, minocycline, metronidazole, and tetracycline) tested by E-test strips. Antimicrobial resistance genes were detected in six of the eight isolates analyzed, of which five carried tet(32) and one erm(B). Overall, susceptibility to the nine antibiotics tested was high except for azithromycin in the isolate that carried erm(B). Moreover, susceptibility to tetracycline, doxycycline, and minocycline was lower in those isolates that carried tet(32). The genetic surroundings of the detected genes suggested their inclusion in mobile genetic elements that might be transferrable to other bacteria. These findings suggest that, despite showing high susceptibility to several antibiotics, F. alocis might obtain new antimicrobial resistance traits due to its acceptance of mobile genetic elements with antibiotic resistance genes in their genome.
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The oral cavity is particularly susceptible to viral infections that are self-recovering in most cases. However, complications may appear in severe cases and/or immunocompromised subjects. Cetylpyridinium chloride (CPC)-containing mouthwashes are able to decrease the infectivity of the SARS-CoV-2 virus by disrupting the integrity of the viral envelope. Here, we show that CPC, as the active ingredient contained in commercialized, exerts significant antiviral activity against enveloped viruses, such as HSV-1, but not against non-enveloped viruses, such as HPV. CPC-containing mouthwashes have been used as antiseptics for decades, and thus, they can represent a cost-effective measure to limit infection and spread of enveloped viruses infecting the oral cavity, aiding in reducing viral transmission.
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Anti-Infecciosos Locais , COVID-19 , Herpesvirus Humano 1 , Humanos , Antissépticos Bucais/farmacologia , Cetilpiridínio/farmacologia , SARS-CoV-2 , Anti-Infecciosos Locais/farmacologiaRESUMO
Aim: Our aim was to compare the prevalence and load of nine pathobionts in subgingival samples of healthy individuals and periodontitis patients from four different countries. Methods: Five hundred and seven subgingival biofilm samples were collected from healthy subjects and periodontitis patients in Belgium, Chile, Peru and Spain. The prevalence and load of Eubacterium brachy, Filifactor alocis, Fretibacterium fastidiosum, Porphyromonas endodontalis, Porphyromonas gingivalis, Selenomonas sputigena, Treponema denticola, Tannerella forsythia and Treponema socranskii were measured by quantitative PCR. Results: The association with periodontitis of all species, except for T. socranskii, was confirmed in all countries but Peru, where only P. endodontalis, P. gingivalis and T. denticola were found to be significantly associated. Moreover, most species showed higher loads at greater CAL and PPD, but not where there was BOP. Through Principal Component Analysis, samples showed clearly different distributions by diagnosis, despite observing a smaller separation in Peruvian samples. Conclusions: Unlike prevalence, relative load was found to be a reliable variable to discriminate the association of the species with periodontitis. Based on this, F. alocis, P. endodontalis, P. gingivalis, T. denticola and T. forsythia may be biomarkers of disease in Belgium, Chile and Spain, due to their significantly higher abundance in periodontitis patients.
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BACKGROUND: SARS-CoV-2 is continuously disseminating worldwide. The development of strategies to break transmission is mandatory. AIM OF THE STUDY: To investigate the potential of cetylpyridinium chloride (CPC) as a viral inhibitor. METHODS: SARS-CoV-2 Virus Like-Particles (VLPs) were incubated with CPC, a potent surfactant routinely included in mouthwash preparations. RESULTS: Concentrations of 0.05% CPC (w/v) commonly used in mouthwash preparations are sufficient to promote the rupture of SARS-CoV-2 VLP membranes. CONCLUSION: Including CPC in mouthwashes could be a prophylactic strategy to keep SARS-CoV-2 from spreading.
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Aviation emissions of nitrogen oxides (NOx) alter the composition of the atmosphere, perturbing the greenhouse gases ozone and methane, resulting in positive and negative radiative forcing effects, respectively. In 1981, the International Civil Aviation Organization adopted a first certification standard for the regulation of aircraft engine NOx emissions with subsequent increases in stringency in 1992, 1998, 2004 and 2010 to offset the growth of the environmental impact of air transport, the main motivation being to improve local air quality with the assumed co-benefit of reducing NOx emissions at altitude and therefore their climate impacts. Increased stringency is an ongoing topic of discussion and more stringent standards are usually associated with their beneficial environmental impact. Here we show that this is not necessarily the right direction with respect to reducing the climate impacts of aviation (as opposed to local air quality impacts) because of the tradeoff effects between reducing NOx emissions and increased fuel usage, along with a revised understanding of the radiative forcing effects of methane. Moreover, the predicted lower surface air pollution levels in the future will be beneficial for reducing the climate impact of aviation NOx emissions. Thus, further efforts leading to greater fuel efficiency, and therefore lower CO2 emissions, may be preferable to reducing NOx emissions in terms of aviation's climate impacts.
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Introduction: Antibiotic resistance is widely found even among bacterial populations not having been exposed to selective pressure by antibiotics, such as tetracycline. In this study we analyzed the tetracycline-resistant subgingival microbiota of healthy subjects and of patients with periodontitis, comparing the prevalence of tet genes and their multidrug resistance profiles. Methods: Samples from 259 volunteers were analyzed, obtaining 813 tetracycline-resistant isolates. The prevalence of 12 antibiotic resistance genes was assessed, and multidrug profiles were built. Each isolate was identified by 16S rRNA sequencing. Differences in qualitative data and quantitative data were evaluated using the chi-square test and the Mann-Whitney-U test, respectively. Results: tet(M) was the most frequently detected tet gene (52.03%). We observed significant differences between the prevalence of tet(M), tet(W), tet(O), tet(32) and tet(L) in both populations studied. Multidrug resistance was largely observed, with resistance to kanamycin being the most detected (83.64%). There were significant differences between the populations in the prevalence of kanamycin, chloramphenicol, and cefotaxime resistance. Resistant isolates showed significantly different prevalence between the two studied groups. Conclusion: The high prevalence of multidrug resistance and tetracycline resistance genes found in the subgingival microbiota, highlights the importance of performing wider and more in-depth analysis of antibiotic resistance in the oral microbiota.
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AIM: Capsular polysaccharides play an important role in the virulence of Gram-positive and Gram-negative bacteria. In Porphyromonas gingivalis, six serotypes have been described based on capsular antigenicity and its pathogenicity has been correlated both in vitro and in animal models. This study aimed to investigate the differential response of human dendritic cells (DCs) when stimulated with different P. gingivalis capsular serotypes. MATERIALS AND METHODS: Using different multiplicity of infection (MOI) of the encapsulated strains K1-K6 and the non-encapsulated K(-) strain of P. gingivalis, the mRNA expression levels for interleukin (IL)-1beta, IL-2, IL-5, IL-6, IL-10, IL-12, IL-13, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, and TNF-beta in stimulated DCs were quantified by real-time reverse transcription-polymerase chain reaction. RESULTS: All P. gingivalis capsular serotypes induced a T-helper type 1 (Th1) pattern of cytokine expression. K1- and K2-stimulated DCs expressed higher levels of IL-1beta, IL-6, IL-12p35, IL-12p40, and IFN-gamma and at lower MOI than DCs stimulated with the other strains. CONCLUSIONS: These results demonstrate a differential potential of P. gingivalis capsular serotypes to induce DC responses and a higher capacity of strains K1 W83 and K2 HG184 than other K serotypes to trigger cytokine expression.
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Cápsulas Bacterianas/imunologia , Citocinas/imunologia , Células Dendríticas/imunologia , Porphyromonas gingivalis/imunologia , Antígenos de Bactérias/imunologia , Cápsulas Bacterianas/classificação , Células Cultivadas , Citocinas/análise , Humanos , Interferon gama/análise , Interleucina-10/análise , Interleucina-12/análise , Subunidade p35 da Interleucina-12/análise , Subunidade p40 da Interleucina-12/análise , Interleucina-13/análise , Interleucina-1beta/análise , Interleucina-2/análise , Interleucina-5/análise , Interleucina-6/análise , Linfotoxina-alfa/análise , Polissacarídeos Bacterianos/imunologia , Porphyromonas gingivalis/classificação , Porphyromonas gingivalis/patogenicidade , Sorotipagem , Células Th1/imunologia , Fator de Necrose Tumoral alfa/análise , VirulênciaRESUMO
Tetracycline resistance can be achieved through tet genes, which code for efflux pumps, ribosomal protection proteins and inactivation enzymes. Some of these genes have only been described in either Gram-positive or Gram-negative bacteria. This is the case of tet(B), which codes for an efflux pump and, so far, had only been found in Gram-negative bacteria. In this study, tet(B) was detected in two clinical Streptococcus oralis strains isolated from the gingival sulci of two subjects. In both cases, the gene was completely sequenced, yielding 100% shared identity and coverage with other previously published sequences of tet(B). Moreover, we studied the expression of tet(B) using RT-qPCR in the isolates grown with and without tetracycline, detecting constitutive expression in only one of the isolates, with no signs of expression in the other one. This is the first time that the presence and expression of the tet(B) gene has been confirmed in Gram-positive bacteria, which highlights the potential of the genus Streptococcus to become a reservoir and a disseminator of antibiotic resistance genes in an environment so prone to horizontal gene transfer as is the oral biofilm.
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OBJECTIVES: The aim was to answer three relevant questions: can systemic antimicrobials be efficacious if the biofilm is not disrupted? Can the type of debridement of the subgingival biofilm impact upon the clinical outcomes of the adjunctive antimicrobial therapy? Is the efficacy of the adjunctive systemic antimicrobial therapy dependent on the quality of the debridement of the subgingival biofilm and the sequence debridement-antibiotic usage? MATERIAL AND METHODS: Relevant papers were searched, critically analysed and their data were extracted. RESULTS: For the first question, studies assessing susceptibility of bacteria in biofilms, and clinical studies evaluating systemic antimicrobials as monotherapy, were reviewed. For the second question, clinical studies comparing systemic antimicrobials as adjuncts to non-surgical debridement or to periodontal surgery and clinical trials using systemic antibiotics with periodontal surgery were evaluated. For the third question, a previous systematic review was updated. CONCLUSION: If systemic antimicrobials are indicated in periodontal therapy, they should be adjunctive to mechanical debridement. There is not enough evidence to support their use with periodontal surgery. Indirect evidence suggests that antibiotic intake should start on the day of debridement completion, debridement should be completed within a short time (preferably <1 week) and with an adequate quality, to optimize the results.
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Antibacterianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Periodontite/tratamento farmacológico , Terapia Combinada , Desbridamento , Raspagem Dentária , Combinação de Medicamentos , Farmacorresistência Bacteriana , Humanos , Periodontite/microbiologia , Periodontite/cirurgia , Aplainamento Radicular , Resultado do TratamentoRESUMO
AIM: To investigate the subgingival microbiota of distinct periodontitis patient populations, in Chile, Colombia and Spain, using identical clinical and bacteriological methods. MATERIAL AND METHODS: In this multicentre study, 114 chronic periodontitis patients were selected. Patients were examined using an identical clinical protocol and pooled subgingival samples were obtained from each patient. Samples were processed in the three laboratories by means of culturing under identical clinical and microbiological protocols. Total anaerobic counts and frequency of detection and proportions of nine periodontal pathogens were calculated. Variables were analysed by means of anova, chi(2), Kruskal-Wallis and Dunn's multiple comparison tests. RESULTS: The Colombian population demonstrated greater severity of periodontitis, with significantly deeper mean probing pocket depth, and had a significantly lower percentage of current smokers. When comparing samples from the three patient populations, the total counts were significantly higher in the Colombian patients. The numbers of putative pathogens differed among groups. Tannerella forsythia was found less frequently in Chilean samples, while Parvimonas micra and enteric rods differed significantly among the three population groups. CONCLUSION: Significant differences among Chile, Colombia and Spain existed regarding the frequency and proportions of specific periodontal pathogens in the subgingival microbiota of periodontitis patients.