Demystifying interactions between micro organisms in oral candidiasis biofilm: the key to enhancing treatments

Introduction: candida albicans is a fungal pathogen that can provoke diseases ranging from oral infections to life-threatening systemic disorders. It is now recognized that oral bacteria, such as the genus Streptococcus, establish synergistic relationships with C. albicans, which could potentially increase the fungi's virulence and pathogenicity. Objective: this narrative review aimed to discuss the Candida-Streptococcus mechanisms of interactions and their contribution to increasing oral candidiasis severity. In addition, it provides a background of biofilm formation and potential therapeutical targets. Sources of Data: searches for papers in English were performed in the Pubmed database until May 2022. MeSH and free terms related to the field were used. In vitro studies were selected, tabulated, and qualitative and quantitative data were analyzed descriptively. Synthesis of Data: among the early colonizers bacteria, evidence pointed out that S. gordonnii and S. oralis have major implications in oral candidiasis, in which mixed biofilms increase the infection severity and challenge the host's defense. On the other hand, the outcomes of the interaction between C. albicans and S. mitis, S. sanguinis, or S. mutans remain little explored in the oral candidiasis scenario, albeit evidence pointed out an enhanced fungus population and virulence factors. Conclusion: overall, considering the polymicrobial profile of the infection and the potential to increase Candida-related disease severity, therapeutical strategies should also consider bacteria management.

Introdução: candida albicans é um patógeno fúngico que pode provocar doenças que variam de infecções orais a distúrbios sistêmicos com risco de vida. Hoje se reconhece que as bactérias orais, como o gênero Streptococcus, estabelecem relações sinérgicas com C. albicans, o que pode potencialmente aumentar a virulência e patogenicidade do fungo. Objetivo: esta revisão narrativa teve como objetivo discutir os mecanismos de interação Candida-Streptococcus e sua contribuição para o agravamento da candidíase oral. Além disso, fornece uma breve explanação sobre a formação do biofilme e potenciais alvos terapêuticos. Fonte dos dados: foi realizada pesquisa na base de dados Pubmed para a busca de artigos publicados em Inglês até maio de 2022. Para isso, foram utilizados descritores relacionados ao tema. Estudos in vitro foram selecionados, tabulados e seus resultados quantitativos e qualitativos analisados descritivamente. Síntese dos dados: entre as bactérias denominadas colonizadores iniciais, evidências apontam que S. gordonnii e S. oralis têm implicações importantes na candidíase oral, na qual biofilmes mistos aumentam a gravidade da infecção e desafiam a defesa do hospedeiro. Por outro lado, os desfechos das interações entre C. albicans e S. mitis, S. sanguinis ou S. mutans permanecem pouco explorados no cenário da candidíase oral, apesar de evidências apontarem um aumento dapopulação fúngica e de fatores de virulência. Conclusão: de maneira geral, considerando o perfil polimicrobiano da infecção e o potencial agravamento das doenças provocadas por Candida spp, as estratégias terapêuticas não devem estar focadas apenas no fungo, mas também devem considerar o manejo da bactéria.

Influência de laminados cerâmicos cimentados sobre dentes naturais sem término cervical na microbiota do fluido gengival crevicular: estudo clínico, prospectivo e longitudinal usando PCR em tempo real / Influence of laminate veneers cemented over natural teeth without finish line on the microbiota of gingival crevicular fluid: clinical, prospective and longitudinal study using real-time PCR

Objetivo: quantificar bactérias colonizadoras do sulco gengival em paralelo à verificação do comportamento clínico periodontal e da adaptação marginal de laminados cerâmicos cimentados sobre dentes sem término cervical. Métodos: 73 laminados cerâmicos em dissilicato de lítio monolítico foram cimentados sobre dentes naturais sem término cervical e com a margem cervical posicionada cerca de 0,5mm no interior do sulco gengival. Para todos os dentes foi feita a coleta do fluido gengival crevicular (FGC) previamente à cimentação da restauração (baseline) e em 7, 180 e 365 dias após a cimentação para quantificação das bactérias S. mitis, P. intermedia e P. gingivalis através de PCR em tempo real. Clinicamente foram avaliados os parâmetros índice de placa visível (IPV), sangramento à sondagem (SS), profundidade de sondagem (PS), perda de inserção clínica (PIC), recessão gengival (RG) e a adaptação marginal da restauração em baseline, 7, 15, 30, 60, 180 e 365 dias. Foram obtidas réplicas da região cervical para análise da adaptação marginal por microscopia eletrônica de varredura (MEV). Resultados: Não houve diferença estatisticamente significante para o IPV, PS, SS em todos os períodos analisados (Anova, p>0,05). Não houve registro de PIC e RG. Houve diferença estatisticamente significante para S. mitis na comparação entre 180 e 365 dias (Dunn, p=0,03). Não foi detectado P. intermedia em nenhum dos sítios e não houve diferença estatisticamente significante para P. gingivalis em todos os tempos do estudo (Friedman, p>0,05). Todas as restaurações receberam o conceito alfa para a adaptação marginal nas análises clínica e microscópica. Conclusões: o sobrecontorno causado pelo laminado cerâmico não contribuiu para o acúmulo de placa na região cervical e para alterações no comportamento clínico periodontal, microbiológico e microscópico em relação aos mesmos dentes antes do tratamento restaurador(AU)

Purpose: quantify colonizing bacteria of the gingival sulcus, in parallel to the verify of the periodontal clinical behavior and the marginal adaptation of natural teeth restored with ceramic veneers without finish line. Methods: 73 ceramic veneers in monolithic lithium disilicate were cemented onto natural teeth without finish line and with the cervical margin positioned about 0.5mm inside the gingival sulcus. Gingival crevicular fluid (GCF) was collected for all teeth prior to cementation of the restoration (baseline) and 7, 180 and 365 days after cementation to quantify the bacteria S. mitis, P. intermedia and P. gingivalis through of real-time PCR. Clinically, visible plaque index (PIV), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), gingival recession (GR) and marginal adaptation were evaluated at baseline, 7, 15, 30, 60, 180 and 365 days. Replicas of the cervical region were obtained for analysis of marginal adaptation by scanning electron microscopy (SEM). Results: There was no statistically significant difference for PIV, PD, BOP in all periods analyzed (Anova, p>0.05). There were no records of CAL and RG. There was a statistically significant difference for S. mitis in the comparison between 180 and 365 days (Dunn, p=0.03). P. intermedia was not detected in any of the analyzed samples. There was no statistically significant difference for P. gingivalis at all study times (Friedman, p>0.05). All restorations had an alpha concept for marginal adaptation in clinical and SEM analysis. Conclusions: the overcontouring caused by ceramic veneers did not contribute to the accumulation of plaque in the cervical region and to changes in the clinical, microbiological and microscopic behavior in relation to the same teeth before the restorative treatment(AU)

Chemical Composition, Antibacterial and Antifungal Potential of an Extract From the Leaves of Guapira Graciliflora Mart. Against Oral Microorganisms of Dental Interest

Abstract Objective: To perform an in vitro analysis of antibacterial and antifungal potential of an alcoholic extract from the leaves of Guapira Graciliflora Mart. against oral microorganisms and determine its chemical composition. Material and Methods: A hydroalcoholic extract of the leaves form G. graciliflora was obtained through maceration, vacuum concentration and freeze-drying. Antibacterial and antifungal activities were evaluated against Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis, Streptococcus parasanguinis, Streptococcus mitis and strains of Candida albicans using broth microdilution method. Phytochemical analysis determined the total phenolic compounds, protein concentration and total of sugars present in the extract. Results: G. Graciliflora demonstrated antifungal activity against the LM 11 and LM 410 clinical isolates of C. albicans (MIC 0.5 mg/mL and 2 mg/mL, respectively). The other microorganisms tested were resistant to the extract. The phytochemical analysis revealed 3% proteins, 13% total sugars and 17% phenolic compounds. Conclusion: G. Graciliflora has antifungal activity against clinical strains of C. albicans and exhibits proteins, sugars and phenolic compounds in its chemical composition.

Antimicrobial activity of mouth rinses against bacteria that initially colonizes dental's surface / Atividade antimicrobiana de enxaguatórios bucais sobre bactérias que iniciam a colonização das superfícies dentais

Abstract Introduction Much advertising in mouthwash is conveyed in all media appealing to the anti-plaque effect and rendering a disservice to the community. Mouth rinses are available over-the-count and differ on their compositions and antimicrobial effectiveness. Objective In this study, we evaluated the antimicrobial activity of 35 widely available mouth rinses against bacterial species involved in initiation of dental biofilm - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius, and Streptococcus sanguinis. Material and method The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of the evaluated mouth rinses were determined according to the Clinical & Laboratory Standards Institute protocols. Data were submitted to Kruskal-Wallis test and Mann-Whitney post hoc (α=0.05). Result About 70% of the mouth rinses achieved high antibacterial activity and 30%, a low antibacterial activity against all the species tested. The most ineffective mouth rinse showed antibacterial activity (MIC) at 1:1 dilution, while the most effective showed activity even at 1:2048 dilution, which may imply prolonged effect in the mouth. About 51% of mouth rinses showed bactericidal activity, and it was verified that cetylpyridinium chloride or chlorhexidine digluconate containing in the formulation were associated with the highest activity. Conclusion Most - but not all - mouth rinses commercially available are effective in inhibiting in vitro initial colonizers of dental surfaces.

Resumo Introdução Muita publicidade sobre enxaguatórios bucais é veiculada em todos os meios de comunicação apelando para o efeito anti-placa e prestando um desserviço à comunidade. Grande quantidade de enxaguatórios bucais está disponível no mercado e estes diferem em suas composições e eficácia antimicrobiana. Objetivo Neste estudo, avaliamos a atividade antimicrobiana de 35 enxaguatórios bucais amplamente disponíveis contra espécies bacterianas envolvidas na iniciação do biofilme dental - Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus salivarius e Streptococcus sanguinis. Material e método A Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) dos enxaguatórios avaliados foram determinadas de acordo com os protocolos do Clinical & Laboratory Standards Institute. Os dados foram submetidos ao teste Kruskal-Wallis e Mann-Whitney post hoc (α=0,05). Resultado Aproximadamente 70% dos enxaguatórios bucais alcançaram alta atividade antibacteriana e 30%, baixa atividade antibacteriana contra todas as espécies testadas. O enxaguatório bucal mais ineficaz mostrou atividade antibacteriana (CIM) na diluição de 1:1, enquanto a mais eficaz mostrou atividade mesmo na diluição de 1:2048, o que pode implicar em efeito prolongado na boca. Cerca de 51% dos enxaguatórios bucais apresentaram atividade bactericida, e verificou-se que formulações contendo cloreto de cetilpiridíneo ou digluconato de clorexidina estavam associados à maior atividade. Conclusão A maior parte - mas não todos - dos enxaguatórios bucais comercialmente disponíveis são eficazes na inibição de colonizadores iniciais de superfícies dentárias in vitro.

Native 1st Metatarso-Phalangeal Joint Infection: A Rare Case Report / 대한족부족관절학회지

Septic arthritis is a serious medical condition that can lead to significant complications if misdiagnosed or mismanaged. A rare case of a 1st metatarso-phalangeal joint septic arthritis in a native joint is presented in a patient with no significant risk factors. A 41-year-old patient was referred by his general practitioner owing to ongoing pain and swelling over his native 1st metatarso-phalangeal joint with difficulty on weightbearing for three months. After a series of investigations, including blood tests and a foot magnetic resonance imaging, which were inconclusive, the patient was led to the operating theatre for sampling and washout of his joint. The samples taken in the theatres revealed septic arthritis with Streptococcus mitis as the causative microorganism. The patient was treated with six weeks of oral antibiotics with a good functional outcome. This case report illuminates this rare condition and makes foot and ankle surgeons aware of its existence. A high suspicion for this condition can prevent misdiagnosis and mismanagement.

Antimicrobial Effect of Acanthopanax sessiliflorum Fruit Extracts against Selected Oral Bacteria / 치위생과학회지

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.

Comparisons of IgA response in saliva and colostrum against oral streptococci species

Abstract The present study compared IgA specificity against oral streptococci in colostrum and saliva samples. Sixty-two mother-and-child pairs were included; samples of colostrum (C) and saliva (MS) were collected from the mothers and saliva samples were collected from babies (BS). The specificity of IgA against Streptococcus mutans and S. mitis were analyzed by western blot. Only 30% of babies’ samples presented IgA reactivity to S. mutans, while 74 and 80% of MS and C, respectively, presented this response. IgA reactivity to S. mutans virulence antigens (Ag I/II, Gtf and GbpB) in positive samples showed differences between samples for Gtf and especially for GbpB (p < 0.05), but responses to Ag I/II were similar (p > 0.05). The positive response of Gtf-reactive IgA was different between C (90%) and MS (58%) samples (p < 0.05), but did not differ from BS (p > 0.05). GbpB was the least detected, with 48 and 26% of C and MS, and only 5% of BS samples presenting reactivity (p > 0.05). Eight percent of MS and C samples presented identical bands to SM in the same time-point. In conclusion, the differences of IgA response found between C and MS can be due to the different ways of stimulation, proliferation and transportation of IgA in those secretions. The colostrum has high levels of IgA against S. mutans virulence antigens, which could affect the installation and accumulation process of S. mutans, mainly by supplying anti-GbpB IgA to the neonate.

Utility of a Direct 16S rDNA PCR and Sequencing for Etiological Diagnosis of Infective Endocarditis

BACKGROUND: Cases of infective endocarditis (IE) require prompt etiological diagnosis for effective treatment. Molecular methods can aid in rapid and reliable diagnosis of culture-negative IE cases. We evaluated the utility of 16S rDNA PCR and sequencing in determining the causative agents of IE in valve tissues, especially when specimens were obtained after initiation of antimicrobial therapy. METHODS: We performed 16S rDNA PCR and sequencing in heart valve specimens and medical records review of 80 patients who underwent protocol-based cardiac surgery from 2013 to 2015. One patient did not meet the criteria for IE. Sixty-five (81.3%) and 14 pa-tients (17.5%) were diagnosed as having definite IE and possible IE, respectively. Blood and heart valve biopsy tissue were examined by using routine microbiological methods. RESULTS: Blood cultures in our hospital were IE-positive for 33 patients (41.8%), whereas 49 patients (62.0%) showed positive blood cultures when initial blood cultures performed at the referring hospital were included. Eighteen (22.8%) and 40 patients (50.6%) were IE-positive in valve tissue cultures and 16S rDNA PCR, respectively. Bacteria in the Streptococcus mitis group (n=26) were the most common etiological agents of IE. Eight (10.1%) culture-negative specimens tested positive by 16S rDNA PCR. In five of eight PCR-positive and culture-negative cases, fastidious or anaerobic organisms were the cause of IE. CONCLUSIONS: Direct 16S rDNA PCR and sequencing can be used as a supplementary method to conventional blood and biopsy culture testing, especially in culture-negative IE cases that are negative for IE by culture.

Bactericidal Effect of the Aos Denti Germ for Denture Cleansing Effervescent Tablet against Oral Microorganisms

Human mouth environment is known to include a variety bacteria, including Streptococcus spp., Staphylococcus spp., Actinomyces spp., Lactobacillus spp., Candida spp., Enterobacteriaceae, et al. Human oral microorganisms can cause dental caries, gingivitis, periodontitis, respiratory tract infection, and cardiovascular disease. Thus, right denture cleaning is essential to oral and general human health. The aim of this study was to evaluate the bactericidal effect of a sodium dichloroisocyanurate-based effervescent tablet (Aos Denti Germ, Aos Company, Chungbuk, Korea) against oral microorganisms. A total of 5 species Streptococcus spp. (Streptococcus anginosus, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, and Streptococcus sobrinus), Actinomyces oris, Candida albicans, and Escherichia coli were used in this study. All strains were exposed to the distilled water prepared with effervescent tablet. After the exposure, the mixture of strains and effervescent tablet was inoculated onto blood agar or MacConkey agar plate and cultured at 36℃. All strains were killed immediately on exposure to effervescent tablet. The results suggested that effervescent tablet could be used as an effective denture cleanser for dental hygiene.

A Case of Splenic Botryomycosis Caused by Streptococcus mitis in a Patient with a Previous Distal Gastrectomy / 대한내과학회지

Botryomycosis is an uncommon chronic suppurative bacterial infection of the skin and visceral organs seen primarily in immunocompromised patients. Here, we report a case of splenic botryomycosis caused by Streptococcus mitis in a 53-year-old immunocompetent woman with a history of distal gastrectomy for advanced gastric cancer.

Tricuspid and pulmonary valve endocarditis associated with double-chambered right ventricle / 고신대학교의과대학학술지

We report a rare case of tricuspid valve and pulmonary valve endocarditis associated with a double-chambered right ventricle in an adult female with pulmonary artery aneurysm and septic pulmonary embolism by Streptococcus mitis. She was treated with aggressive antibiotic therapy followed by debridement of the infective lesion of tricuspid valve, pulmonary valve replacement using xenograft and resection of obstructing muscular bundles in right ventricle.

Antimicrobial and cytotoxic activity of Ferula gummosa plant essential oil compared to NaOCl and CHX: a preliminary in vitro study

OBJECTIVES: The usage of medicinal plants as natural antimicrobial agents has grown in many fields including dental medicine. The aim of this in vitro study was three-fold: (i) to determine the chemical compositions of the Ferula gummosa essential oil (FGEO), (ii) to compare the antimicrobial efficacy of the oil with sodium hypochlorite (NaOCl) and chlorhexidine (CHX), (iii) to assess the toxic behavior of FGEO in different concentrations compared to 5% NaOCl and 0.2% CHX. MATERIALS AND METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to determine the chemical compositions of the oil. The disk diffusion method and a broth micro-dilution susceptibility assay were exploited to assess the antimicrobial efficacy against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mitis, and Candida albicans. The cytocompatibility of the FGEO was assessed on L929 fibroblasts, and compared to that of NaOCl and CHX. RESULTS: Twenty-seven constituents were recognized in FGEO. The major component of the oil was beta-pinene (51.83%). All three irrigants significantly inhibited the growth of all examined microorganisms compared to the negative control group. FGEO at 50 microg/mL was effective in lower concentration against Enterococcus faecalis than 5% NaOCl and 0.2% CHX, and was also more potent than 0.2% CHX against Candida albicans and Staphylococcus aureus. FGEO was a cytocompatible solution, and had significantly lower toxicity compared to 5% NaOCl and 0.2% CHX. CONCLUSIONS: FGEO showed a promising biological potency as a root canal disinfectant. More investigations are required on the effectiveness of this oil on intracanal bacterial biofilms.

Identification of Bacterial Flora on Cellular Phones of Dentists

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

A Case of Spontaneous Bacterial Peritonitis with Bacteremia Caused by Shewanella algae

Human infection caused by Shewanella algae is rare, which usually occurred after direct contact with seawater or ingestion of raw seafood in the immunocompromised host. There have been anecdotal reports about Shewanella infections in human, but their pathogenic role and microbiologic data are limited. Here, we report a fatal case of spontaneous bacterial peritonitis with bacteremia due to S. algae in a 57-year-old male with liver cirrhosis who had no history of exposure to seawater or raw seafood. Polymicrobial infection with Streptococcus mitis and Escherichia coli was combined and the patient died in spite of early appropriate antimicrobial therapy and early goal-directed therapy for sepsis.

Novel Partial Anomalous Pulmonary Venous Connection Associated with Brain Abscess

BACKGROUND: Right-to-left vascular shunts are associated with brain abscess. CASE REPORT: We present a 47-year-old female with a cryptogenic left thalamic abscess on which Streptococcus mitis grew upon aspiration. Computed tomography of the chest with contrast agent revealed an anomalous connection between the left superior pulmonary and brachiocephalic veins. A right-to-left shunt was confirmed in a transthoracic echocardiogram study in which bubbles were injected into the left arm; this shunt had not previously been noted upon right-arm injection. CONCLUSIONS: We recommend aggressive evaluation for right-to-left shunts in patients who present with cryptogenic brain abscesses. In addition to imaging, this should include a bubble-based study with left-arm saline injection.

Molecular Discrimination of Mitis Group Streptococci Isolated from Koreans using RpoB Nucleotide Sequences

Mitis group streptococci (MGS) were classified based on the nucleotide sequences 16S rRNA gene (16S rDNA) and comprised 13 Streptococcus species. However, 16S rDNA homogeneity among MGS was too high to discriminate between clinical strains at the species level, notably between Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, and Streptococcus pseudopneumoniae. The purpose of this study was to discriminate between 37 strains of MGS isolated from Korean oral cavities using phylogenetic analysis of the DNA-dependant RNA polymerase beta-subunit gene (rpoB). 16S rDNA and rpoB from clinical strains of MGS were sequenced using the dideoxy chain termination method and analyzed using MEGA version 5 software. The resulting phylogenetic data showed that the rpoB sequences could delineate clinical strains of MGS at the species level. Phylogenetic analysis of rpoB is therefore a useful approach for identifying MGS at the species level.

A Case of Endogenous Streptococcus Mitis Endophthalmitis in a Patient with Staphylococcus Aureus Sepsis

PURPOSE: To report a case of endogenous endophthalmitis due to Streptococcus mitis in a patient with Staphylococcus aureus sepsis. CASE SUMMARY: A 77-year-old male complained of sudden visual loss and ocular pain in his right eye and was treated with intravenous antibiotics for Staphylococcus aureus sepsis. With a diagnosis of endogenous endophthalmitis, the patient received pars plana vitrectomy and intravitreal injection of antibiotics. Vitreous fluid was obtained before surgery, and the organism was identified as Streptococcus mitis. Twenty-one days after the surgery, intraocular inflammation was stabilized, and visual acuity was improved from light perception to 20/60. CONCLUSIONS: Appropriate sampling and culture of vitreous fluid are important for the diagnosis of endogenous endophthalmitis. The possibility that the causative organism of endogenous endophthalmitis may be different from the result of blood culture should be considered.

Queratopatía cristalina: diagnóstico clínico y microbiológico de una infección corneal infrecuente causada por el grupo Streptococcus mitis

El objetivo del presente informe es describir un caso de queratopatía cristalina causada por microorganismos pertenecientes al grupo Streptococcus mitis en una paciente que concurrió a la consulta oftalmológica por molestias en su ojo derecho. Al examen oftalmológico presentó un punto de sutura interrumpida de nylon 10-0 sin tensión y con secreciones mucosas adheridas. El punto flojo fue retirado bajo normas de asepsia. Se indicó colirio de moxifloxacina al 0,5 %; el ojo tuvo una evolución adecuada, con una correcta epitelización. Sin embargo, luego de 15 días desarrolló un infiltrado blanquecino arboriforme. Se tomó una muestra en el quirófano, enhebrando el trayecto intraestromal de la sutura retirada con sutura de vicryl 7-0. Se indicaron colirios de vancomicina con 50 mg/ml. El infiltrado se mantuvo estable durante 45 días, luego se incrementó el tamaño y se produjo necrosis tisular con peligro de perforación corneal. Se realizó un recubrimiento conjuntival bipediculado. La paciente evolucionó favorablemente y luego de la retracción espontánea del recubrimiento, se observó leucoma cicatrizal y neovasos corneales.

Crystalline keratopathy: an infrequent corneal infection produced by the Streptococcus mitis group. The objective of this report is to describe a case of crystalline keratopathy caused by the Streptococcus mitis group corresponding to a patient who attended hospital for discomfort in his right eye. The ophthalmological examination showed an interrupted stitch of 10-0 nylon suture without tension and with attached mucus secretions. The loose suture was removed under aseptic conditions. Moxifloxacin 0.5 % eye drops were topically indicated. The treated eye successfully epithelialized and evolved favorably. However, after 15 days, a white tree-shaped infiltrate developed. A corneal sample was taken in the operating room, threading the intrastromal path of the removed stitch with a 7-0 vicryl suture. Vancomycin 50 mg/ml drops were indicated. The infiltrate, which was stable for 45 days, later increased its size and tissue necrosis occurred with danger of corneal perforation. A bipedicle conjunctival flap was performed in the affected corneal area, which evolved favorably. After spontaneous conjunctival flap retraction, only corneal scarring and neovascularization outside the visual axis were observed.

Eficácia antimicrobiana do extrato do Croton sonderianus Müll. sobre bactérias causadoras da cárie dentária / Antimicrobial efficacy of the extract of Croton sonderianus Müll. on bacteria that cause dental caries

Este trabalho tem como objetivo avaliar a atividade antimicrobiana do extrato do Croton sonderianus (marmeleiro) frente a bactérias que fazem parte do biofilme dental, como Streptococcus salivaris, mutans, mitis, sanguis e sobrinus. Os ensaios foram realizados pela técnica de difusão em meio sólido com base no tamanho dos halos de inibição. Os mesmos procedimentos foram utilizados com a clorexidina. Os resultados mostraram que todas as amostras ensaiadas foram sensíveis ao extrato com CIM (mg.mL-1) de 1:16 (0,62%), 1:32 (0,31%), 1:64 (0,15%), 1:32 (0,31%), 1:16 (0,62%), respectivamente. S. mitis foi a linhagem mais sensível. Os resultados mostram a potencialidade do extrato do Croton sonderianus na inibição do crescimento bacteriano de micro-organismos formadores do biofilme dental, sugerindo a possibilidade do emprego desse extrato como meio alternativo no controle desses patógenos naprática odontológica.

This study aims to evaluate the antimicrobial activity of the extract of Croton sonderianus (marmeleiro) against bacteria that are part of the biofilm, such as Streptococcus salivaris, mutans, mitis, sanguis, sobrinus. The tests were carried out by diffusion technique on solid medium based on the size of inhibition zones. The same procedures were used with chlorhexidine. The results showed that all samples tested were sensitive to the extract with MIC (mg.mL-1) of 1:16 (0.62%), 1:32 (0.31%), 1:64 (0.15%) 1:32 (0.31%), 1:16 (0.62%), respectively. S. mitis strainwas more sensitive. The results show the potential of the extract of Croton sonderianus in growth inhibition of microorganisms forming the biofilm suggesting the possibility of using this extract as an alternative means to control these pathogens in dental practice.

Cell surface proteins in S. pneumoniae, S. mitis and S. oralis

Streptococcus pneumoniae, a major human pathogen, is closely related to the commensal species S. mitis and S. oralis. S. pneumoniae surface proteins are implicated in virulence and host interaction of this species, but many of them have recently been detected in S. mitis B6 in silico. We tested for the presence of such genes usinga set of eight S. mitis and eleven S. oralis strains from different geographic locations. An oligonucleotide microarray was designed based on the genomes of S. pneumoniae R6 and TIGR4 as well as S. mitis B6 to include 63 cell surface proteins. The S. pneumoniae genes encoding neuraminidases, hyaluronidase and pneumolysin were also included. In addition to comparative genomic hybridization experiments, homologues were identified in silico in the genome of S. oralis Uo5. The results document that many S. pneumoniae related surface proteins are ubiquitously present among the Mitis group of streptococci. All 19 samples hybridized with the pavA probe representing a gene important for adherence and invasion of S. pneumoniae. Only eight genes were not recognized in any strain, including the S. pneumoniae PcpC gene as the only virulence gene of the S. pneumoniae core genome.The fact that only 12 out of 26 genes present in the S. oralis Uo5 genome could be detected by microarray analysis confirms the sequence variation of surface components