Occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing head and neck radiotherapy

The aim of this study was to evaluate the occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing radiotherapy (RT) for treatment of head and neck cancer. Fifty patients receiving RT were examined before, during and 30 days after RT. Saliva, mucosa, and biofilm samples were collected and microorganisms were detected by culture and polymerase chain reaction (PCR). The most prevalent yeasts in patients submitted to RT were Candida albicans, C. tropicalis, C. krusei, C. glabrata and C. parapsilosis. Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, and Pseudomonas were the most frequently cultivated bacteria. Before RT, targeted bacteria were cultivated from 22.2% of edentulous patients and 16.6% of dentate patients; 30 days after RT, these microorganisms were recovered from 77.8% edentulous and 46.8% dentate patients. By PCR, these microorganisms were detected from all edentulous patients, 78.1% of dentate patients. The presence of Gram-negative enteric roads and fungi was particularly frequent in patients presenting mucositis level III or IV. Modifications in the oral environment due to RT treatment seem to facilitate the colonization of oral cavity by members of family Enterobacteriaceae, genera Enterococcus and Candida.

Microbiota associated with chronic osteomyelitis of the jaws

Chronic osteomyelitis of maxilla and mandible is rare in industrialized countries and its occurrence in developing countries is associated with trauma and surgery, and its microbial etiology has not been studied thoroughly. The aim of this investigation was to evaluate the microbiota associated with osteomyelitis of mandible or maxilla from some Brazilian patients. After clinical and radiographic evaluation, samples of bone sequestra, purulent secretion, and biopsies of granulomatous tissues from twenty-two patients with chronic osteomyelitis of mandible and maxilla were cultivated and submitted for pathogen detection by using a PCR method. Each patient harbored a single lesion. Bacterial isolation was performed on fastidious anaerobe agar supplemented with hemin, menadione and horse blood for anaerobes; and on tryptic soy agar supplemented with yeast extract and horse blood for facultative bacteria and aerobes. Plates were incubated in anaerobiosis and aerobiosis, at 37ºC for 14 and 3 days, respectively. Bacteria were cultivated from twelve patient samples; and genera Actinomyces, Fusobacterium, Parvimonas, and Staphylococcus were the most frequent. By PCR, bacterial DNA was detected from sixteen patient samples. The results suggest that cases of chronic osteomyelitis of the jaws are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws are mainly related to microorganisms from the oral environment, and periapical and periodontal infections may act as predisposing factors.

Occurrence of yeasts, enterococci and other enteric bacteria in subgingival biofilm of HIV-positive patients with chronic gingivitis and necrotizing periodontitis

The purpose of this study was to determine the prevalence of enteric bacteria and yeasts in biofilm of 80 HIV-positive patients with plaque-associated gingivitis or necrotizing periodontitis. Patients were subjected to extra, intra oral and radiographic examinations. The oral hygiene, bleeding on probing, gingival conditions, and attachment loss were evaluated. Clinical specimens were collected from gingival crevices or periodontal pockets, transferred to VMGA III, diluted and transferred to Sabouraud Dextrose agar with 100 µg/ml of chloramphenicol, peptone water, EVA broth, EMB agar, SS agar, Bile esculin agar and Brilliant green agar. Isolation of yeasts was carried out at room temperature, for 3-7 days; and for the isolation of enteric microorganisms plates were incubated at 37ºC, for 24-48 h. The yeasts identification was performed according to the carbon and nitrogen assimilation, fermentation of carbohydrates and germ tube formation. Bacteria were identified according to their colonial and cellular morphologies and biochemical tests. Yeasts were identified as Candida albicans and its occurrence was more common in patients with CD4+ below 200/mm³ and was affected by the extension of periodontal involvement (P = 0.0345). Enteric bacteria recovered from clinical specimens were identified as Enterobacter sakazakii, Enterobacter cloacae, Serratia liquefaciens, Klebsiella oxytoca and Enterococcus sp. Enterobacteriaceae and enterococci were detected in 32.5% of clinical samples from patients with necrotizing periodontitis. In conclusion, non-oral pathogenic bacteria and C. albicans were more prevalent in periodontal sites of HIV-positive patients with necrotizing periodontitis and chronic gingivitis.

O objetivo desse estudo foi avaliar a ocorrência de bactérias entéricas e leveduras no biofilme subgengival de pacientes HIV-positivos com gengivite crônica ou periodontite necrosante. Os pacientes foram submetidos a exame clínico e radiográfico e de higiene bucal, sangramento à sondagem, condições gengivais e a perda de inserção. Os espécimes clínicos de sulcos gengivais ou bolsas periodontais foram inoculados em ágar Sabouraud dextrose com 100 mg/ml de cloranfenicol, água peptonada, caldo EVA, ágar EMB, ágar SS, ágar Bile esculina e ágar verde brilhante. O cultivo de leveduras foi realizado à temperatura ambiente, de 3-7 dias; das enterobactérias a 37ºC de 24-48 h. A identificação das leveduras foi realizada pela assimilação de carbono e nitrogênio, fermentação de açucares e formação de tubo germinativo. As bactérias de acordo com a morfologia celular e colonial e testes bioquímicos. Foram identificadas Candida albicans e sua prevalência foi maior em pacientes com contagens de CD4+ 200/mm³, e sua ocorrência foi afetada pela extensão da destruição periodontal (P = 0,0345). Enterobacteriaceae e enterococos foram detectados em 32,5% dos pacientes com periodontite necrosante. As enterobactérias foram Enterobacter sakazakii, E. cloacae, Serratia liquefaciens, Klebsiella oxytoca e Enterococcus sp. Concluiu-se que bactérias patogênicas exógenas à cavidade bucal e C. albicans podem ser detectadas no biofilme subgengival de pacientes HIV-positivos com periodontite necrosante e gengivite.

Distribution of biotypes and leukotoxic activity of Aggregatibacter actinomycetemcomitans isolated from Brazilian patients with chronic periodontitis

Aggregatibacter actinomycetemcomitans is an important etiologic agent of the periodontitis and is associated with extra-oral infections. In this study, the detection of the ltxA gene as well as the ltx promoter region from leukotoxic A. actinomycetemcomitans isolated from 50 Brazilian patients with periodontitis and 50 healthy subjects was performed. The leukotoxic activity on HL-60 cells was also evaluated. Leukotoxic activity was determined using a trypan blue exclusion method. The 530 bp deletion in the promoter region was evaluated by PCR using a PRO primer pair. A. actinomycetemcomitans was detected by culture and directly from crude subgingival biofilm by PCR using specific primers. By culture, A. actinomycetemcomitans was detected in nine (18%) of the periodontal patients and one (2%) healthy subject. However, by PCR, this organism was detected in 44% of the periodontal patients and in 16% of the healthy subjects. It was verified a great discrepancy between PCR detection of the ltx operon promoter directly from crude subgingival biofilm and from bacterial DNA. Only one periodontal sample harbored highly leukotoxic A. actinomycetemcomitans. Moreover, biotype II was the most prevalent and no correlation between biotypes and leukotoxic activity was observed. The diversity of leukotoxin expression by A. actinomycetemcomitans suggests a role of this toxin in the pathogenesis of periodontal disease and other infectious diseases.

Aggregatibacter actinomycetemcomitans é um importante agente etiológico da periodontite e produz infecções extra-bucais. Neste estudo, foram detectados os biótipos, o gene ltxA associado à produção de leucotoxina e o promotor ltx em A. actinomycetemcomitans de pacientes com e sem periodontite. A atividade leucotóxica sobre células HL-60 também foi avaliada. A atividade leucotóxica foi determinada através do método de exclusão do azul de tripam. A deleção de 530 bp no promotor ltx foi avaliada usando-se o par de iniciadores PRO. A. actinomycetemcomitans foi detectado por cultura e por PCR. Por cultura, A. actinomycetemcomitans foi detectado em nove pacientes com periodontite (18%) e em um indivíduo sadio (2%). Por PCR esse microrganismo foi detectado em 44% dos pacientes com periodontite e em 16% dos saudáveis. Verificou-se diferença estatística entre a detecção do promotor do operon ltx, por PCR, diretamente do biofilme subgengival e do DNA bacteriano. Somente uma amostra clínica apresentou A. actinomycetemcomitans altamente leukotóxico. O biótipo II foi o mais prevalente e não foi observada correlação biótipo-atividade leucotóxica. A expressão da leucotoxina por A. actinomycetemcomitans na doença periodontal e outras doenças infecciosas necessita ser avaliado.

Detection of putative periodontal pathogens in subgingival specimens of dogs

In this study, the presence of putative periodontal organisms, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Fusobacterium nucleatum,Dialister pneumosintes,Actinobacillus actinomycetemcomitans,Campylobacter rectus,Eikenella corrodens and Treponema denticola were examined from subgingival samples of 40 dogs of different breeds with (25) and without (15) periodontitis, by using the PCR method. The PCR products of each species showed specific amplicons. Of the 25 dogs with periodontitis, P. gingivalis was detected in 16 (64%) samples, C. rectus in 9 (36%), A. actinomycetemcomitans in 6 (24%), P. intermedia in 5 (20%), T. forsythensis in 5 (20%), F. nucleatum in 4 (16%) and E. corrodens in 3 (12%). T. denticola and D. pneumosintes were not detected in clinical samples from dogs with periodontitis. Moreover, P. gingivalis was detected only in one (6.66%) crossbred dog without periodontitis. Our results show that these microorganisms are present in periodontal microbiota of dogs with periodontitits, and it is important to evaluate the role of these putative periodontal microorganisms play in the periodontitis in household pets particularly, dogs in ecologic and therapeutic terms, since these animals might acquire these periodontopahogens from their respective owners.

Neste estudo, a presença de patógenos periodontais, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Fusobacterium nucleatum, Dialister pneumosintes, Actinobacillus actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens e Treponema denticola foi determinada por PCR, em amostras subgengivais de 40 cães com (25) e sem (15) doença periodontal. Os produtos amplificados pelo PCR para cada espécie bacteriana mostraram amplicons específicos. Dos 25 cães apresentando doença periodontal, P. gingivalis foi detectado em 16 amostras (64%), C. rectus em 9 (36%), A. actinomycetemcomitans em 6 (24%), P. intermedia em 5 (20%), T. forsythensis em 5 (20%), F. nucleatum em 4 (16%) e E. corrodens em 3 (12%). Em nenhuma amostra clínica periodontal foi observada a presença de T. denticola ou D. pneumosintes. Adicionalmente, P. gingivalis foi detectado em apenas um (6,66%) cão saudável, sem raça definida. Nossos resultados mostram que esses microrganismos estão presentes na microbiota periodontal de cães com periodontitis, e isto torna importante a avaliação do papel que esses microrganismos periodontais desempenham na periodontite de animais domésticos, particularmente cães, em termos ecológicos e terapêuticos, desde que esses cães podem adquirir esses periodontopatógenos de seus respectivos proprietários.

Immunoglobulin G proteolytic activity of Actinobacillus actinomycetemcomitans

Actinobacillus actinomycetemcomitans produces a protease to human immunoglobulin G that is an important evasion mechanism. In this study, the proteolytic activity of A. actinomycetemcomitans strain ATCC 43718 on human immunoglobulin G associated with culture supernatant concentrations, the growth period and the period of incubation with immunoglobulin G were evaluated by an enzyme linked immunosorbent assay. The protease fraction was detected by Sephadex G 150 chromatography. The results showed that A. actinomycetemcomitans produced a protease to human immunoglobulin G in the culture supernatant, and the highest activity was achieved witen the concentration was 27.5 mug protein/mL, after culturing for 72 hours and incubating with IgG for 24 hours. The molecular mass of the protease active fraction was from 43 to 150 kDa.

Actinobacillus actinomycetemcomitans produz protease ativa sobre imunoglobulina G humana, sendo um dos mecanismos importantes de escape do microrganismo. No presente trabalho, foi analisada a atividade proteolítica de sobrenadante de cultivo de A. actinomycetemcomitans ATCC 43718 sobre imunoglobulina G humana em função de concentração, tempo de cultivo do microrganismo e tempo de incubação com IgG, por ensaio imunoenzimático. Adicionalmente, foi determinada a fração com atividade de protease por meio de análise de eluatos de cromatografia em coluna de Sephadex G 150. Os resultados obtidos demonstraram que A. actinomycetemcomitans liberou protease ativa sobre imunoglobulina G humana em sobrenadante de cultivo, sendo a sua maior atividade evidenciada na concentração de 27,5 mig proteína/mL, com tempo de cultivo de 72 horas e com 24 horas de incubação com IgG. A massa molecular da fração ativa de protease foi compreendida entre 43 a 150 kDa.

Prevotella intermedia and Porphyromonas gingivalis isolated from osseointegrated dental implants: colonization and antimicrobial susceptibility

The colonization and antimicrobial susceptibility of P. intermedia and P. gingivalis isolated from peri-implant and gingival sulcus samples were determined. Samples were collected from 30 patients submitted to implant in three different times: at the moment of the surgery, 20 and 60 days after the implant installation. Organisms were identified by using a biochemical tests or API 32-A kit and by PCR. The antimicrobial susceptibility was determined by using an agar dilution method. Nineteen P. intermedia (4 from peri-implant sites and 15 from gingival sulcus), and only seven P. gingivalis from gingival sulcus were isolated. Organisms were detected by PCR from seven peri-implant and 32 gingival samples. Bacteria were susceptible to the used antibiotics except to azithromycin with 65% of resistance for P. intermedia strains. Both tested species were susceptible to cadmium, nickel and palladium, and showed different resistance rates to titanium, aluminum and mercuric chloride. Most of P. intermedia strains were resistant to lead, silver, copper, titanium, zinc, aluminum and mercuric chloride. Bacteria colonized implants after 60 days of surgery and PCR may be used as a tool for bacterial detection in implantology.

Neste estudo foram avaliadas a colonização e a susceptibilidade a antimicrobianos de P. intermedia e P. gingivalis isolados de amostras de sulcus gengivais e peri-implantares. As amostras foram coletadas de 30 pacientes submetidos a implantes, em três tempos diferentes: no momento da cirurgia, 20 e 60 dias após a instalação do implante. Os organismos foram identificados por testes bioquímicos ou por kit comercial API 32-A e por PCR. A susceptibilidade antimicrobiana foi determinada usando-se o método de diluição em ágar. Foram isolados dezenove P. intermedia (quatro de peri-implantites e 15 de sulco gengival) e somente sete P. gingivalis de sulco gengival. Pelo PCR os organismos foram detectados de sete amostras sete peri-implantares e de 32 gengivais. As bactérias foram susceptíveis aos antibióticos usados exceto para azitromicina com 65% de resistência para P. intermedia. As espécies avaliadas foram sensíveis para cádmio, níquel e paládio, e mostraram diferentes faixas de resistência para titânio, alumínio e bicloreto de mercúrio. A maioria de P. intermedia foi resistente para chumbo, prata, cobre, titânio, zinco, alumínio e bicloreto de mercúrio. As bactérias colonizaram implantes após 60 dias de cirurgia e PCR pode ser usado como ferramenta para a detecção bacteriana na implantodontia.

PCR detection of four periodontopathogens from subgingival clinical samples

In this study, A. actinomycetemcomitans, B. forsythus, P. gingivalis and F. nucleatum were identified from subgingival plaque from 50 periodontal patients and 50 healthy subjects. Subgingival clinical samples were collected with sterilized paper points and transported in VMGA III. From all the diluted clinical samples (1:10), DNA was obtained by boiling, and after centrifugation the supernatant was used as template. Specific primers for each bacterial species were used in PCR. PCR amplification was sensitive to identify these organisms. PCR products from each species showed a single band and can be used to identify periodontal organisms from clinical specimens. PCR detection odds ratio values for A. actinomycetemcomitans and B. forsythus were significantly associated with disease showing a higher OR values for B. forsythus (2.97, 95% CI 1.88 - 4.70). These results suggest a strong association among the studied species and the periodontal lesion.

Em nosso estudo quatro periodontopatógenos foram isolados e identificados de placas subgengivais de 50 pacientes com doença periodontal e de 50 indivíduos sadios. As placas subgengivais foram coletadas com pontas de papel e transportadas em VMGA III. Foram realizadas diluições seriadas das amostras clínicas (1:10), e os DNA foram obtidos por fervura. Iniciadores específicos para cada bactéria foram usados no PCR. As amplificações mostraram-se sensíveis na identificação de A. actinomycetemcomitans, B. forsythus, P. gingivalis e F. nucleatum. As reações de PCR produziram bandas específicas para cada espécie e podem ser usadas na identificação desses organismos periodontais diretamente das amostras clínicas. Os valores de odds ratio para a detecção de A. actinomycetemcomitans e B. forsythus foram significativamente associados com a doença periodontal mostrando altos valores de OR para B. forsythus (2,97, 95% CI 1,88 - 4,70). Esses resultados sugerem uma forte associação entre os organismos estudados e a lesão periodontal.