Infectious endarteritis in aortic coarctation: two spectra of an infrequent disease / Endarterite infecciosa na coarctação da aorta: dois espectros de uma doença pouco frequente

ABSTRACT Objective: To describe two different degrees of clinical commitment and results in the evolution of infectious endarteritis in patients without a previous diagnosis of aortic coarctation. Case description: Two male patients aged 13 and 9 years old were admitted. The first due to a fever for 2 months, which started after dental cleaning, and the second due to high blood pressure, both patients with asthenia and weight loss. In the first case, the transthoracic echocardiogram showed aortic coarctation, and the transesophageal echocardiogram showed the presence of vegetations in the post-coarctation area, without pseudoaneurysms, with blood culture positive for Streptococcus mitis. This patient was treated for six weeks with crystalline penicillin, resolving the infection without complications. The second case was assessed for high blood pressure with a history of fever, and was treated with antibiotics. When performing a transthoracic echocardiogram, aortic coarctation was observed with a saccular image classified as a pseudoaneurysm by angiography and tomography. Blood culture was negative, and the patient developed an episode of hematemesis whose initial etiology could not be determined. Before surgical repair, he had a second episode of copious hematemesis with hypovolemic shock and death. Comments: We need to have a high index of clinical suspicion to establish the diagnosis of aortic coarctation complicated by endarteritis and start the appropriate antibiotic treatment, always maintaining surveillance for the early detection of pseudoaneurysms.

RESUMO Objetivo: Descrever dois diferentes graus de comprometimento clínico e resultados na evolução de endarterite infecciosa em pacientes sem diagnóstico prévio de coarctação da aorta. Descrição do caso: Dois pacientes do sexo masculino com idades entre 13 e nove anos foram internados. O primeiro por febre durante dois meses, iniciada após limpeza dentária. O segundo por hipertensão arterial. Ambos com astenia e perda de peso. No primeiro caso, o ecocardiograma transtorácico mostrou coarctação da aorta e o ecocardiograma transesofágico revelou vegetações na área pós-coarctação, sem pseudoaneurismas. A hemocultura foi positiva para de Streptococcus mitis. Este paciente foi tratado por seis semanas com penicilina cristalina, resolvendo a infecção sem complicações. O segundo caso foi avaliado pela presença de hipertensão arterial, com história de febre tratada com antibióticos. Ao realizar o ecocardiograma transtorácico, observou-se coarctação da aorta com imagem sacular classificada como pseudoaneurisma pela angiografia e tomografia. A hemocultura foi negativa. O paciente desenvolveu um episódio de hematêmese, cuja etiologia inicial não pôde ser determinada. Antes da correção cirúrgica, apresentou um segundo episódio de hematêmese profusa, com choque hipovolêmico e óbito. Comentários: Devemos ter um alto índice de suspeição clínica para poder estabelecer o diagnóstico de coarctação da aorta complicada com endarterite e iniciar o tratamento antibiótico adequado. É preciso manter a vigilância para a detecção precoce de pseudoaneurismas.

The Distribution of Eight Antimicrobial Resistance Genes in Streptococcus oralis, Streptococcus sanguinis, and Streptococcus gordonii Strains Isolated from Dental Plaque as Oral Commensals.

It has been proposed that oral commensal bacteria are potential reservoirs of a wide variety of antimicrobial resistance genes (ARGs) and could be the source of pathogenic bacteria; however, there is scarce information regarding this. In this study, three common streptococci of the mitis group (S. oralis, S. sanguinis, and S. gordonii) isolated from dental plaque (DP) were screened to identify if they were frequent reservoirs of specific ARGs (blaTEM, cfxA, tetM, tetW, tetQ, ermA, ermB, and ermC). DP samples were collected from 80 adults; one part of the sample was cultured, and from the other part DNA was obtained for first screening of the three streptococci species and the ARGs of interest. Selected samples were plated and colonies were selected for molecular identification. Thirty identified species were screened for the presence of the ARGs. From those selected, all of the S. sanguinis and S. oralis carried at least three, while only 30% of S. gordonii strains carried three or more. The most prevalent were tetM in 73%, and blaTEM and tetW both in 66.6%. On the other hand, ermA and cfxA were not present. Oral streptococci from the mitis group could be considered frequent reservoirs of specifically tetM, blaTEM, and tetW. In contrast, these three species appear not to be reservoirs of ermA and cfxA.

PcsB Expression Diversity Influences on Streptococcus mitis Phenotypes Associated With Host Persistence and Virulence.

S. mitis is an abundant member of the commensal microbiota of the oral cavity and pharynx, which has the potential to promote systemic infections. By analyzing a collection of S. mitis strains isolated from the oral cavity at commensal states or from systemic infections (blood strains), we established that S. mitis ubiquitously express the surface immunodominant protein, PcsB (also called GbpB), required for binding to sucrose-derived exopolysaccharides (EPS). Immuno dot blot assays with anti-PcsB antibodies and RT-qPCR transcription analyses revealed strain-specific profiles of PcsB production associated with diversity in pcsB transcriptional activities. Additionally, blood strains showed significantly higher levels of PcsB expression compared to commensal isolates. Because Streptococcus mutans co-colonizes S. mitis dental biofilms, and secretes glucosyltransferases (GtfB/C/D) for the synthesis of highly insoluble EPS from sucrose, profiles of S. mitis binding to EPS, biofilm formation and evasion of the complement system were assessed in sucrose-containing BHI medium supplemented or not with filter-sterilized S. mutans culture supernatants. These analyses showed significant S. mitis binding to EPS and biofilm formation in the presence of S. mutans supernatants supplemented with sucrose, compared to BHI or BHI-sucrose medium. In addition, these phenotypes were abolished if strains were grown in culture supernatants of a gtfBCD-defective S. mutans mutant. Importantly, GtfB/C/D-associated phenotypes were enhanced in high PcsB-expressing strains, compared to low PcsB producers. Increased PcsB expression was further correlated with increased resistance to deposition of C3b/iC3b of the complement system after exposure to human serum, when strains were previously grown in the presence of S. mutans supernatants. Finally, analyses of PcsB polymorphisms and bioinformatic prediction of epitopes with significant binding to MHC class II alleles revealed that blood isolates harbor PcsB polymorphisms in its functionally conserved CHAP-domain, suggesting antigenic variation. These findings reveal important roles of PcsB in S. mitis-host interactions under commensal and pathogenic states, highlighting the need for studies to elucidate mechanisms regulating PcsB expression in this species.

Análise de fatores de virulência de Candida albicans na associação com Streptococcus mitis e Streptococcus sanguinis in vitro e in vivo / Analysis of virulence factors of Candida albicans in association with Streptococcus mitis and Streptococcus sanguinis in vitro and in vivo

O objetivo foi avaliar as interações entre Candida albicans (ATCC 18804) com Streptococcus mitis (49456) e Streptococcus sanguinis (10556) in vitro e in vivo avaliando-se a possível influência destas associações, na expressão de genes, na filamentação e formação de biofilme de Candida albicans. A formação de biofilme, foi realizado mono e multiespécie em placa de 96 poços por 48 h à 37 ºC com 5% CO2. Os biofilmes foram desagregados e diluídos para semeadura em ágar e após incubação as UFC/mL foram contadas. A filamentação de C. albicans, in vitro foi realizada em placas de 24 poços e in vivo em Galleria mellonella, com análise histológica e contagem de UFC/mL. A avaliação da expressão gênica de ALS1, ALS3, BRC1, CPH1, EFG1 e HWP1, foi realizada por PCR em tempo real utilizando o gene normalizador ACT1. Os resultados da UFC/mL (p < 0.05), demonstrou que o biofilme de C. albicans monoespécie apresentou maior crescimento, quando comparado com o biofilme associado com S. mitis (p = 0,001) ou com S. sanguinis (p = 0,001). A filamentação in vitro demonstrou que a interação com S. mitis inibiu a filamentação de C. albicans (p = 0,0006), entretanto, a interação com S. sanguinis não inibiu (p = 0,1554). Os genes ALS1, ALS3 e HWP1 foram super expressos na interação com S. mitis. A interação com S. sanguinis, promoveu super expressão dos genes ALS3 e HWP1. Os genes BRC1, CPH1 e EFG1 foram super expressos na interação com S. mitis e sub expressos, na interação com S. sanguinis. Não houve diferença estatística nos estudos in vivo de filamentação e UFC/mL. Conclui-se que in vitro, S. mitis e S. sanguinis foram capazes de inibir a formação de biofilme de C. albicans. Assim como a interação com S. mitis inibiu a sua filamentação. A interação com S. mitis parece aumentar o fator de virulência de C. albicans, quanto a expressão dos genes de aderência ALS1, ALS3 e HWP1, bem como na associação com S. sanguinis (ALS3 e HWP1). Os genes de formação de biofilme, BRC1, CPH1 e EFG1, na interação com S. mitis promoveu aumento do fator de virulência(AU)

The objective was to evaluate the interactions between Candida albicans (ATCC 18804) with Streptococcus mitis (49456) and Streptococcus sanguinis (10556) in vitro and in vivo evaluating the possible influence of these associations, in the expression of genes, in the filamentation and biofilm formation of Candida albicans. Biofilm formation was performed mono- and multispecies in 96-well plate for 48 h at 37 ºC with 5% CO2. Biofilms sonicated and diluted for sowing on agar and after incubation the colonies counted to obtain the colony forming units (CFU/mL). The filamentation in vitro was performed in 24-well plate and in vivo Galleria mellonella, with histological and CFU/mL. The evaluation of gene expression ALS1, ALS3, BRC1, CPH1, EFG1 and HWP1 was performed by real-time PCR using the normalizing gene ACT1. The results of CFU/ml (p<0.05), found that C. albicans biofilm monoespécie showed increased growth, as compared to the biofilm associated with S. mitis (p = 0.001) and S. sanguinis (p = 0.001). The filamentation in vitro demonstrated that the interaction with S. mitis inhibited C. albicans filamentation (p = 0.0006), interaction with S. sanguinis could not (p = 0.1554). The ALS1, ALS3, HWP1 gene, were superexpressed in S. mitis interaction. Interaction with S. sanguinis, promoted overexpression of ALS3 and HWP1 genes. The BRC1 genes, CPH1 and EFG1 were super expressed in interaction with S. mitis and sub expressed when there was interaction with S. sanguinis. There was no statistical difference in the in vivo studies of filamentation and CFU/mL. It follows that in vitro, S. mitis and S. sanguinis were able to inhibit the formation of C. albicans biofilms. Like the interaction with S. mitis inhibited its filamentation. The interaction with S. mitis appears to increase the virulence factors of C. albicans. ALS1, ALS3, HWP1 as the expression of adhesion genes, and as well as in association with S. sanguinis (ALS3 and HWP1). Biofilm formation genes, BRC1, CPH1 and EFG1 in interaction with S. mitis promoted increased virulence factor(AU)

Salivary antibody response to streptococci in preterm and fullterm children: a prospective study.

OBJECTIVES: Secretory immunoglobulins present in mucosa surfaces represent the first line of defense of the adaptive immune system against infectious challenges. Preterm (PT) neonates' humoral immunity is diminished compared to full-term (FT) newborns. The identification of important antigens (Ags) of virulence of oral species may help in the investigation of the mechanisms of antigenic stimulation and the development of the mucosal immune response. In the present study, we measured saliva levels of immunoglobulins A (IgA) and M (IgM) and characterized the specificity of IgA against Ags of several streptococcal species found early in life. METHODS: This was a prospective observational study. Salivary IgA (sIgA) antibody responses to bacterial species that are prototypes of pioneer (Streptococcus mitis, S. sanguinis, S. gordonii) and pathogenic (Streptococcus mutans) microorganisms of the oral cavity were studied in FT and PT children in two visits: at birth (T0) and at 3 months of age (T3). Salivas from 123 infants (72 FT and 51 PT) were collected during the first 10h after birth (T0) and again at 3 months of age (T3). Salivary levels of IgA and IgM antibodies were analysed by enzyme-linked immunosorbent assay (ELISA). A subgroup of 26 FT and 24 PT children were compared with respect to patterns of antibody specificities against different streptococci Ags using Western blot assays. RESULTS: No significant differences (P>0.05) in salivary levels of IgA and IgM between FT and PT babies were found at birth. At T3, mean sIgA values were similar between groups and sIgM levels were significantly higher in PT than FT (P<0.05). Western blot assays identified positive IgA response to streptococci in the majority of children, especially in the FT group. There were some differences between groups in relation to the frequency of children with positive response to Ags and intensity of IgA response. In general, oral streptococci Ags were more frequently detected and bands were more intense in FT than in PT, especially in T3. Prospective analysis of patterns of sIgA against Ags of different streptococcal species revealed an increase in complexity of the sIgA antibody response from the first day of birth (T0) to T3 in PT and FT. CONCLUSION: The patterns of sIgA response to streptococci Ags appear to be influenced by the gestational age, which might reflect the level of immunological maturity of the mucosal immune system.

Biofilmes multiespécies de Candida albicans associados com Streptococcus mitis e Streptococcus sanguinis: estudo in vitro e in vivo / Multi-species biofilms of Candida albicans associated with Streptococcus mitis and Streptococcus sanguinis: a study in vitro and in vivo

Streptococcus sanguinis e Streptococcus mitis são colonizadores pioneiros do biofilme bucal e podem causar endocardite bacteriana. Candida albicans está presente na cavidade bucal de forma comensal, possui capacidade de formar biofilme e causar candidose bucal. O objetivo desse trabalho foi avaliar as interações entre C. albicans com S. sanguinis e S. mitis em biofilmes e suas influências in vivo em modelo experimental de invertebrado Galleria mellonella. Para o estudo da interação de C. albicans (ATCC 18804) com S. sanguinis (ATCC 7073) e S. mitis (ATCC 4945) foram formados biofilmes monoespécie e multiespécies de C. albicans com os micro-organismos (na concentração de 107 células/mL) em fundo de placa de 96 poços por 48 h, incubados em estufa a 37 °C com 5% CO2. Após crescimento, os biofilmes foram desprendidos e obtidas diluições decimais as quais foram semeadas em meios seletivos. Após incubação por 48 h/37 °C foi obtida a contagem de unidades formadoras de colônias por mililitro (UFC/mL). Em paralelo, foram realizados ensaios colorimétricos com o sal XTT, a fim de mensurar a atividade metabólica de C. albicans nos biofilmes isolados e associados, seguindo de leitura a 492 nm, e o resultado expresso em absorbância (Abs). No estudo in vivo, primeiro foram determinadas as concentrações subletais dos micro-organismos, e inoculadas em G. mellonella, e observado o efeito de C. albicans, S. mitis e S. sanguinis nas lagartas, avaliando se curva de sobrevivência. Avaliação morfológica dos biofilmes foi realizada por microscopia eletrônica de varredura (MEV). Os dados de contagem de UFC/mL e da atividade metabólica foram submetidos à análise de normalidade, e como foi observada distribuição normal, os resultados foram analisados estatisticamente pelos testes t de Student (para duas variáveis) e Tukey (para três ou mais variáveis), considerando-se diferença estatística quando p<0,05. Os dados obtidos na curva de sobrevivência de G. mellonella foram analisados pelo ...

Streptococcus sanguinis and Streptococcus mitis are pioneering colonizers of oral biofilm and can cause bacterial endocarditis. Candida albicans is present in the oral cavity in a commensal manner and also has the ability to form biofilm and cause oral candidiasis. The aim of this study was to evaluate the interactions between C. albicans with S. sanguinis and S. mitis biofilms and their influences in vivo on an experimental invertebrate model of Galleria mellonella. To study the interaction of C. albicans (ATCC 18804) with S. sanguinis (ATCC 7073) and S. mitis (ATCC 4945) monospecies and multispecies biofilms were formed of C. albicans and with micro-organisms (a concentration of 107 cells/ml) in the bottom of a 96-well plate for 48 h, incubated at 37 °C with 5% CO₂. After growth, biofilms were detached, and decimal dilutions were plated on selective media. After incubation for 48 h/37 °C the count of colony forming units per milliliter (CFU/mL) was obtained. Alongside, XTT salt colorimetric assays were carried in order to measure the metabolic activity of isolated and associated C. albicans biofilms, following reading at 492 nm, and the result expressed in absorbance (Abs). In the in vivo study, first the sublethal concentrations of microorganisms were determined, and inoculated into G. mellonella, and the effect of C. albicans, S. mitis and S. sanguinis in caterpillars was observed, evaluating the survival curve. Morphological evaluation of the biofilms was performed by scanning electron microscopy (SEM). The count of CFU/mL and metabolic activity were submitted to normality analisis, and as a normal distribution was observed, the results were statistically analyzed by Student's t test (for two variables) and Tukey (for three or more variables) considering statistical difference at p < 0.05. The G. mellonella survival curves data were analyzed by log-rank method. Streptococci influenced the reduction of biofilms of C. albicans, and the percentage ...

Photodynamic inactivation mechanism of Streptococcus mitis sensitized by zinc(II) 2,9,16,23-tetrakis[2-(N,N,N-trimethylamino)ethoxy]phthalocyanine.

Photoinactivation of Streptococcus mitis induced by zinc(II) 2,9,16,23-tetrakis[2-(N,N,N-trimethylamino)ethoxy]phthalocyanine (ZnEPc(4+)) was studied under different experimental condition in order to obtain information about the photodynamic processes and the cellular damage. A 3 log decrease in S. mitis survival was found in cell suspensions (~2×10(8) cells/mL) incubated with 2 µM ZnEPc(4+) and irradiated for 30 min with visible light (54 J/cm(2)). Also, S. mitis cells growth was not detected in broth treated with 5 µM ZnEPc(4+) under continuous irradiation. Studies of photodynamic action mechanism showed that the cells were protected in the presence of azide ion, while the addition of mannitol did not produce a significant effect on the survival. Moreover, the photocytotoxicity was increased in D2O indicating the interference of singlet molecular oxygen. On the other hand, it was found that ZnEPc(4+) interacts strongly with calf thymus DNA in solution but photocleavage of DNA was only detected after long irradiation periods. After S. mitis photoinactivation, modifications of genomic DNA were not observed by electrophoresis. In contrast, the transmission electron microscopy showed structural changes in the S. mitis cells, exhibiting mesosome-like structures. After 2h irradiation, the cytoplasm showed segregation patterns and PDI appeared to have effects on the cell wall, including variability in wall thickness. Also, the presence of bubbles was detected on the cell surface by scanning electron microscopy. However, the photodamage to the cell envelope was insufficient to cause the release of intracellular biopolymers. Therefore, modifications in the cytoplasmic biomolecules and alteration in the cell barriers could be mainly involved in S. mitis photoinactivation. It can be concluded that photosensitization by ZnEPc(4+) mainly involved a type II photoprocess, while alteration in the cytoplasmatic components and modifications in the cell envelope were the major cause for the photoinactivation of S. mitis.

Actividad antibacteriana de Pelargonium peltatum (L.) L'Hér. sobre Streptococcus mutans, Streptococcus sanguis y Streptococcus mitis frente a clorhexidina / Antibacterial activity of Pelargonium peltatum (L.) L'Her. against Streptococcus mutans, Streptococcus sanguis and Streptococcus mitis versus chlorhexidine

Introducción: Pelargonium peltatum (L.) L'Hér (geranio hiedra) es ampliamente utilizado en medicina natural para el tratamiento de enfermedades bucales, pero se desconocen aún sus propiedades farmacológicas, actividad antibacteriana y la composición de sus fitoconstituyentes. Objetivo: realizar un estudio comparativo de la actividad antibacteriana in vitro del extracto acuoso obtenido de las hojas de Pelargonium peltatum (L.) L'Hér (geranio hiedra) sobre Streptococcus mutans, Streptococcus sanguis y Streptococcus mitis, frente a la clorhexidina. Métodos: para el ensayo antibacteriano se empleó el método de difusión en agar. Se trabajó con 18 muestras de microorganismos de cada especie mencionada, aisladas de los pacientes de una clínica dental. Posteriormente, se prepararon 6 concentraciones diferentes del extracto acuoso, para comparar la actividad antibacteriana frente al colutorio de clorhexidina. El análisis fitoquímico preliminar se realizó mediante el ensayo a la gota. Los datos obtenidos se sometieron a análisis estadísticos como estimadores de media y dispersión, análisis de varianza unifactorial y prueba de Tukey. Resultados: la más alta actividad antibacteriana se obtuvo en la concentración de 400 mg/mL y la más baja en la de 25 mg/mL del extracto acuoso, sobre las tres especies de Streptococcus, en comparación con la clorhexidina; con efecto similar a la concentración de 200 mg/mL. El ensayo fitoquímico preliminar indicó la presencia de flavonoides, taninos, esteroides, antocianinas y saponinas. Conclusiones: el extracto acuoso de Pelargonium peltatum tiene actividad antibacteriana sobre Streptococcus mutans, Streptococcus mitis y Streptococcus sanguis.

Introduction: Pelargonium peltatum (L.) L'Her (ivy geranium) is widely used in natural medicine for the treatment of oral disease, but its pharmacological properties, antibacterial activity and phytoconstituent composition are still unknown. Objective: carry out a comparative study of the in vitro antibacterial activity of the aqueous extract obtained from leaves of Pelargonium peltatum (L.) L'Her (ivy geranium) against Streptococcus mutans, Streptococcus sanguis and Streptococcus mitis versus chlorhexidine. Methods: the agar diffusion method was used for the antibacterial assay. A study was conducted of 18 samples of microorganisms from the above-mentioned species, isolated from patients cared for at a dental clinic. Six different concentrations were prepared of the aqueous extract to compare antibacterial activity versus the chlorhexidine gargle. Preliminary phytochemical analysis was conducted by drop assay. The data obtained were subjected to statistical analyses such as mean and dispersion estimators, unifactorial analysis of variance and Tukey's test. Results: the highest antibacterial activity against the three species of Streptococcus was obtained with the 400 mg/ml concentration, and the lowest with the 25 mg/ml concentration of the aqueous extract, in comparison with chlorhexidine, with a similar effect to the 200 mg/ml concentration. The preliminary phytochemical assay revealed the presence of flavonoids, tannins, steroids, anthocyanins and saponins. Conclusions: the aqueous extract of Pelargonium peltatum has antibacterial activity against Streptococcus mutans, Streptococcus mitis and Streptococcus sanguis.

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.