Breastfeeding increases microbial community resilience / Aleitamento materno aumenta a resiliência da comunidade microbiana

Abstract Objective Since the present group had already described the composition of the intestinal microbiota of Brazilian infants under low social economic level, the aim of the present study was to analyze the microbial community structure changes in this group of infants during their early life due to external factors. Methods Fecal samples were collected from 11 infants monthly during the first year of life. The infants were followed regarding clinical and diet information and characterized according to breastfeeding practices. DNA was extracted from fecal samples of each child and subjected to Polymerase Chain Reaction - Denaturing Gradient Gel Electrophoresis. Results The results revealed a pattern of similarity between the time points for those who were on exclusive breastfeeding or predominant breastfeeding. Although there were changes in intensity and fluctuation of some bands, the Denaturing Gradient Gel Electrophoresis patterns in the one-year microbial analysis were stable for breastfeeding children. There was uninterrupted ecological succession despite the influence of external factors, such as complementary feeding and antibiotic administration, suggesting microbiota resilience. This was not observed for those children who had mixed feeding and introduction of solid food before the 5th month of life. Conclusion These results suggested an intestinal microbiota pattern resilient to external forces, due to the probiotic and prebiotic effects of exclusive breastfeeding, reinforcing the importance of exclusive breastfeeding until the 6th month of life.

Resumo Objetivo Como nosso grupo já havia descrito a composição da microbiota intestinal de neonatos brasileiros em baixo nível socioeconômico, o objetivo deste estudo foi analisar alterações estruturais da comunidade microbiana desse grupo de neonatos no início de sua vida devido a fatores externos. Métodos Amostras fecais foram coletadas mensalmente de 11 neonatos durante o primeiro ano de vida. Os neonatos foram acompanhados com relação a informações clínicas e nutricionais e caracterizados de acordo com práticas de amamentação. O DNA foi extraído das amostras fecais de cada criança e submetido a análise através da técnica de Reação em Cadeia da Polimerase - Eletroforese em Gel de Gradiente Desnaturante. Resultados Os resultados revelaram um padrão de similaridade entre seus próprios pontos temporais em indivíduos em aleitamento materno exclusivo ou predominante. Apesar de variações na intensidade e flutuação de algumas bandas, o padrão Eletroforese em Gel de Gradiente Desnaturante na análise microbiana de um ano foi estável em crianças em aleitamento materno. Houve sucessão ecológica ininterrupta apesar da influência de fatores externos, como alimentação complementar e administração de antibióticos, sugeriu resiliência da microbiota. Isso não foi observado nas crianças com alimentação heterogênea e introdução de alimentos sólidos antes do quinto mês de vida. Conclusão Nossos resultados sugerem um padrão de microbiota intestinal resiliente a forças externas, devido a efeitos probióticos e prebióticos do aleitamento materno exclusivo, reforçam a importância do aleitamento materno exclusivo até o sexto mês de vida.

Revisión Bibliográfica: El Microbioma Humano / Bibliographic Review: The Human Microbiome

El microbioma humano se entiende como el enorme conjunto de microorganismo que habitan de manera simbiótica en los distintos órganos de un individuo sano. Existe evidencia suficiente como para afirmar que la colonización de dichos microorganismo sucede inmediatamente después del nacimiento, e incluso algunos autores sostienen que podría suceder dentro del útero. La cantidad de publicaciones científicas que abordan el tema del microbioma han aumentado exponencialmente en los últimos 5 años dejando claro su papel preponderante en la respuesta inmune y en el equilibro salud enfermedad; afirmando que cambios en su ecosistema en términos de cantidad y calidad se asocia con el inicio o la perpetuación de diversas enfermedades.

The human microbiome is understood as the huge group of microorganisms that inhabit symbiotically in a healthy human. There is enough evidence to affirm that the colonization of microorganism happens immediately after birth, in fact some authors claim that it could happen inside the uterus. The number of scientific publications that address the issue ofthemicrobiome have increased exponentially in the last 5 years,making clearthe predominantrole in the immune response and in the health balance; affirming that changes in the ecosystem in terms of quantity and quality, are associated with the initiation or perpetuation of various diseases.

The value of antibody-coated bacteria in tracheal aspirates for the diagnosis of ventilator-associated pneumonia: a case-control study / Utilidade da avaliação de bactérias revestidas por anticorpos em aspirados traqueais para o diagnóstico de pneumonia associada à ventilação mecânica: um estudo caso-controle

ABSTRACT Objective: Ventilator-associated pneumonia (VAP) is the leading type of hospital-acquired infection in ICU patients. The diagnosis of VAP is challenging, mostly due to limitations of the diagnostic methods available. The aim of this study was to determine whether antibody-coated bacteria (ACB) evaluation can improve the specificity of endotracheal aspirate (EA) culture in VAP diagnosis. Methods: We conducted a diagnostic case-control study, enrolling 45 patients undergoing mechanical ventilation. Samples of EA were obtained from patients with and without VAP (cases and controls, respectively), and we assessed the number of bacteria coated with FITC-conjugated monoclonal antibodies (IgA, IgM, or IgG) or an FITC-conjugated polyvalent antibody. Using immunofluorescence microscopy, we determined the proportion of ACB among a fixed number of 80 bacteria. Results: The median proportions of ACB were significantly higher among the cases (n = 22) than among the controls (n = 23)-IgA (60.6% vs. 22.5%), IgM (42.5% vs. 12.5%), IgG (50.6% vs. 17.5%), and polyvalent (75.6% vs. 33.8%)-p < 0.001 for all. The accuracy of the best cut-off points for VAP diagnosis regarding monoclonal and polyvalent ACBs was greater than 95.0% and 93.3%, respectively. Conclusions: The numbers of ACB in EA samples were higher among cases than among controls. Our findings indicate that evaluating ACB in EA is a promising tool to improve the specificity of VAP diagnosis. The technique could be cost-effective and therefore useful in low-resource settings, with the advantages of minimizing false-positive results and avoiding overtreatment.

RESUMO Objetivo: A pneumonia associada à ventilação mecânica (PAVM) é o principal tipo de infecção adquirida no ambiente hospitalar em pacientes em UTIs. O diagnóstico de PAVM é desafiador, principalmente devido a limitações dos métodos diagnósticos disponíveis. O objetivo deste estudo foi determinar se a avaliação de bactérias revestidas por anticorpos (BRA) pode melhorar a especificidade de culturas de aspirado traqueal (AT) no diagnóstico de PAVM. Métodos: Estudo diagnóstico caso-controle envolvendo 45 pacientes sob ventilação mecânica. Amostras de AT foram obtidas de pacientes com e sem PAVM (casos e controles, respectivamente), e verificamos o número de bactérias revestidas com anticorpos monoclonais conjugados com FITC (IgA, IgM ou IgG) ou anticorpo polivalente conjugado com FITC. Utilizando microscopia de imunofluorescência, foi determinada a proporção de BRA em um número fixo de 80 bactérias. Resultados: A mediana das proporções de BRA foi significativamente maior nos casos (n = 22) que nos controles (n = 23) - IgA (60,6% vs. 22,5%), IgM (42,5% vs. 12,5%), IgG (50,6% vs. 17,5%) e polivalente (75,6% vs. 33,8%) - p < 0,001 para todos. A acurácia dos melhores pontos de corte para o diagnostico de PAVM em relação aos BRA monoclonais e polivalentes foi > 95,0% e > 93,3%, respectivamente. Conclusões: O número de BRA em amostras de AT foi maior nos casos que nos controles. Nossos achados indicam que a avaliação de BRA no AT é uma ferramenta promissora para aumentar a especificidade do diagnóstico de PAVM. A técnica pode ser custo-efetiva e, portanto, útil em locais com poucos recursos, com as vantagens de minimizar resultados falso-positivos e evitar o tratamento excessivo.

Sexo Masculino e Hipertensão Arterial São Preditores de Placa à Angiotomografia das Coronárias / Male Gender and Arterial Hypertension are Plaque Predictors at Coronary Computed Tomography Angiography

Background: Systemic Arterial Hypertension (SAH) is one of the main risk factors for Coronary Artery Disease (CAD), in addition to male gender. Differences in coronary artery lesions between hypertensive and normotensive individuals of both genders at the Coronary Computed Tomography Angiography (CCTA) have not been clearly determined. Objective: To Investigate the calcium score (CS), CAD extent and characteristics of coronary plaques at CCTA in men and women with and without SAH. Methods: Prospective cross-sectional study of 509 patients undergoing CCTA for CAD diagnosis and risk stratification, from November 2011 to December 2012, at Instituto de Cardiologia Dante Pazzanese. Individuals were stratified according to gender and subdivided according to the presence (HT +) or absence (HT-) of SAH. Results: HT+ women were older (62.3 ± 10.2 vs 57.8 ± 12.8, p = 0.01). As for the assessment of CAD extent, the HT+ individuals of both genders had significant CAD, although multivessel disease is more frequent in HT + men. The regression analysis for significant CAD showed that age and male gender were the determinant factors of multivessel disease and CS ≥ 100. Plaque type analysis showed that SAH was a predictive risk factor for partially calcified plaques (OR = 3.9). Conclusion: Hypertensive men had multivessel disease more often than women. Male gender was a determinant factor of significant CAD, multivessel disease, CS ≥ 100 and calcified and partially calcified plaques, whereas SAH was predictive of partially calcified plaques. .

Fundamento: Doença Arterial Coronariana (DAC) tem como um dos principais fatores de risco a Hipertensão Arterial Sistêmica (HAS), além do sexo masculino. As diferenças nas lesões de artérias coronarianas entre hipertensos e normotensos de ambos os sexos pela Angiotomografia Computadorizada Coronariana (ATC) ainda não foram claramente determinadas. Objetivo: Investigar Escore de Cálcio (EC), extensão da DAC e as características de placas coronarianas à ATC em homens e mulheres com e sem HAS. Métodos: Estudo transversal prospectivo com 509 pacientes submetidos a ATC para diagnóstico e estratificação de risco de DAC, de novembro de 2011 a dezembro de 2012, no Instituto Dante Pazzanese de Cardiologia. Foram estratificados segundo o gênero e subdivididos de acordo com a presença (HT+) ou ausência (HT-) de HAS. Resultados: As mulheres HT+ apresentaram maior idade (62,3 ± 10,2 vs 57,8 ± 12,8, p = 0,01). Quanto à avaliação de extensão da DAC, os HT+ de ambos os sexos apresentaram DAC significativa, porém a doença multiarterial é mais frequente nos homens HT+. A análise da regressão para DAC significativa mostrou que idade e sexo masculino foram fatores determinantes de doença multiarterial e EC ≥ 100. Já a análise para os tipos de placas mostrou que a HAS se comportou como fator de risco preditor para placas parcialmente calcificadas (OR = 3,9). Conclusão: Homens hipertensos apresentaram mais frequentemente doença multiarterial. O sexo masculino foi fator determinante de DAC significativa, doença multiarterial, EC ≥ 100 e placas calcificadas e parcialmente calcificadas. Enquanto a HAS foi preditora de placas parcialmente calcificadas. .

4-Second Exercise Test: Reference Values for Ages 18–81 Years / Teste de Exercício de 4 Segundos: Valores de Referência dos 18 aos 81 Anos de Idade

Background: Physiological reflexes modulated primarily by the vagus nerve allow the heart to decelerate and accelerate rapidly after a deep inspiration followed by rapid movement of the limbs. This is the physiological and pharmacologically validated basis for the 4-s exercise test (4sET) used to assess the vagal modulation of cardiac chronotropism. Objective: To present reference data for 4sET in healthy adults. Methods: After applying strict clinical inclusion/exclusion criteria, 1,605 healthy adults (61% men) aged between 18 and 81 years subjected to 4sET were evaluated between 1994 and 2014. Using 4sET, the cardiac vagal index (CVI) was obtained by calculating the ratio between the duration of two RR intervals in the electrocardiogram: 1) after a 4-s rapid and deep breath and immediately before pedaling and 2) at the end of a rapid and resistance-free 4-s pedaling exercise. Results: CVI varied inversely with age (r = -0.33, p < 0.01), and the intercepts and slopes of the linear regressions between CVI and age were similar for men and women (p > 0.05). Considering the heteroscedasticity and the asymmetry of the distribution of the CVI values according to age, we chose to express the reference values in percentiles for eight age groups (years): 18–30, 31–40, 41–45, 46–50, 51–55, 56–60, 61–65, and 66+, obtaining progressively lower median CVI values ranging from 1.63 to 1.24. Conclusion: The availability of CVI percentiles for different age groups should promote the clinical use of 4sET, which is a simple and safe procedure for the evaluation of vagal modulation of cardiac chronotropism. .

Fundamento: Reflexos fisiológicos modulados primariamente pelo vago permitem que a frequência cardíaca diminua e aumente rapidamente, após uma inspiração profunda seguida da movimentação rápida dos membros. Essa é a base fisiológica e farmacologicamente validada do teste de exercício de 4 segundos (T4s) para a avaliação da modulação vagal sobre o cronotropismo cardíaco. Objetivo: Apresentar os dados de referência do T4s em adultos saudáveis. Métodos: Após aplicação de rígidos critérios clínicos de inclusão/exclusão foram estudados 1.605 adultos saudáveis (61% homens), entre 18 e 81 anos de idade, submetidos ao T4s, entre 1994 e 2014. No T4s, o Índice Vagal Cardíaco (IVC) foi obtido pela razão entre as durações de dois intervalos RR no traçado eletrocardiográfico: 1) após 4 segundos de inspiração rápida e profunda e imediatamente antes da pedalada; e 2) ao final da pedalada livre e rápida de 4 segundos. Resultados: IVC varia inversamente com a idade (r = - 0,33; p < 0,01) e os interceptos e as inclinações das regressões lineares entre IVC e idade são similares para homens e mulheres (p > 0,05). Considerando a heterocedasticidade e a assimetria da distribuição de IVC em função da idade, optou-se por expressar os valores de referência em percentis para oito faixas etárias (anos): 18-30, 31-40, 41-45, 46-50, 51-55, 56-60, 61-65 e 66+, obtendo-se medianas de IVC progressivamente menores de 1,63 a 1,24. Conclusão: A disponibilização dos percentis de IVC por diferentes faixas etárias deverá facilitar a maior utilização clínica do T4s, um procedimento simples e seguro, para a avaliação da modulação vagal do cronotropismo cardíaco. .

Assessing the Contamination of the External Surfaces of Reused Calen®System Tubes

To determine the presence of contamination on the external surface of reused Calen® System tubes before (TA) and after (TB) the action of four disinfectants: 0.12% chlorhexidine, 2% glutaraldehyde, 70 % alcohol and 1% sodium hypochlorite.Material and Methods:Microbiological collection of 20 tubes from dental clinics was performed with the aid of sterile swabs moistened in saline and rubbed for one minute on their surfaces and inserted in tubes containing 4 ml BHI and incubated under microaerophilic conditions (37°C for 24h) for further Mc Farland (F0.5 to F10) and Gram staining analyses. For disinfection (TB), cotton wicks with 1 ml of disinfectant or distilled water (control) was rubbed for 30 seconds, and after drying by evaporation, new samples were collected from the surfaces, which were submitted tothe same incubation and Gram staining process for the analyses of slides.Results:Prevalence of F4 and F5 in the same proportion in TA and F1 in TB. Gram + cocci were present in 100% of TA and TB, and prevalence of Gram + cocci, Gram + and ûbacilli, spores, Gram -cocci and vibrios in descending order.Conclusion:All external surfacesof reused Calen® System tubes were contaminated before and after disinfection. In descending order, the disinfectant that provided a greater reduction in the Mc Farland scale and thus a greater reduction in the number of microorganisms was 1% sodium hypochlorite, followed by 2% glutaraldehyde, 0.12% chlorhexidine, 70% alcohol and distilled water (control)...

La microbiota intestinal en el desarrollo del sistema inmune del recién nacido / Intestinal microbiota in the development of the neonate's immune system

La microbiota intestinal comprende al conjunto de microorganismos comensales que cohabitan en simbiosis con el individuo. Su programación intraútero y colonización ulterior son factores determinantes en la maduración del sistema inmune. Para enriquecer nuestros conocimientos sobre el efecto de la microbiota intestinal en la maduración del sistema inmune en el niño, se realizó una revisión bibliográfica tras consultar las bases de datos Google, Medline y el Localizador de Información de Salud de Infomed, con la utilización de descriptores como microbiota intestinal, sistema inmune, gut microbiota.

Intestinal microbiota covers the set of commensal microorganisms that live together with the individual. The intrauterine programming and further colonization are determining factors in maturation of the immune system. With the purpose of expanding our knowledge on the effect of the intestinal microbiota in the child´s immune system maturation, a literature review was made supported on Google, Medline databases and the Infomed health information searcher and using intestinal microbiota, immune system, gut microbiota as subject headings.

Aspectos de la respuesta inmune innata en las infecciones intramamarias causadas por Staphylococcus aureus en bovinos / Aspects of the innate immune response to intramammary Staphylococcus aureus infections in cattle

Staphylococcus aureus es el principal agente causante de mastitis bovina en Argentina y en el mundo. Esta bacteria ocasiona infecciones crónicas que generan importantes pérdidas a los productores y la industria lechera. El objetivo de este artículo es caracterizar los mecanismos que intervienen en la infección causada por S. aureus en la glándula mamaria bovina, evaluando dos aspectos diferentes del proceso infeccioso: por un lado, lo vinculado con la respuesta inmune innata por parte del hospedador, y por otro, la capacidad de la bacteria para evadir el sistema inmune e interactuar con diferentes tipos celulares. La exploración de la interacción de S. aureus con el sistema inmune de la glándula mamaria bovina permitirá identificar blancos para delinear nuevas alternativas preventivas o curativas, que contribuyan a evitar o eliminar las infecciones causadas por este organismo

Staphylococcus aureus is the pathogen most frequently isolated from bovine mastitis worldwide, causing chronic intramammary infections that limit profitable dairying. The objective of this article is to characterize the mechanisms involved in S. aureus mammary gland infections considering two different aspects of the infectious process; on the one hand, the aspects involved in the host innate immune response and on the other hand, the capacity of this organism to evade the immune system and interact with different cell types. The exploration of S. aureus interactions with the immune response of bovine mammary gland will help identify targets to outline new preventive or curative alternatives for intramammary infections caused by this organism

Potencial antimicrobiano dos antissépticos de uso popular anapyon®, água rabelo® e malvatricin® sobre microrganismos do meio ambiente oral / Antimicrobial Potential of the Popular Antiseptics Anapyon®, Água Rabelo® and Malvatricin® against Oral Microorganisms

Objetivo: Verificar, ?in vitro?, o potencial antimicrobiano do Anapyon®, da Água Rabelo® e do Malvatricin® sobre microrganismos presentes na cavidade oral.Método: Para realização do experimento, utilizou-se o protocolo sequenciado durante quatro dias que avaliou, através da medida da densidade óptica, o potencial antimicrobiano dos fármacos nos microrganismos (Staphylococcus aureus, Candida tropicalis, Candida parapsilosis e Candida albicans), em suas formas planctônicas, apenas o Malvatricin® foi avaliado sobre as formas de biofilme por ser o único fármaco que apresentou resultados satisfatórios sobre as formas planctônicas. O estudo adotou como controle negativo a água destilada e controle positivo a Clorexidina®. Os resultados obtidos foram submetidos a uma análise estatística com os testes de Kruskal-Wallis e Mann-Whitney. Resultados: Observou-se, através da medida da densidade óptica, que apenas o Malvatricin® apresentou bons resultados na forma planctônica, sendo estes semelhantes ao controle positivo (clorexidina), considerado padrão nos ensaios antimicrobianos em Odontologia. Os resultados do Malvatricin® foram estatisticamente melhores quando comparados aos demais fármacos (Anapyon®, Água Rabelo®) e ao controle negativo. Este resultado foi semelhante para todos os microrganismos estudados: Staphylococcus aureus (p=0,002), Candida tropicalis (p=0,002), Candida parapsilosis (p=0,001) e Candida albicans (p<0,001). Desta forma, apenas o Mavatricin® foi testado para o microrganismo arranjado em biofilme. Observou-se, então, que para a C.albicans e para o S. aureus, houve diferença significativa entre clorexidina e Malvatricin® (p<0,05), com melhores resultados para o clorexidina. Para C. tropicalis, o Malvatricin® diferiu significativamente (p<0,05) da água destilada. Em relação a C.parapsilosis, nenhuma diferença foi observada em relação ao controle negativo (p=0,468). Conclusão: Apesar de alguns fármacos alternativos serem tidos como antimicrobianos, tais propriedades sobre células planctônicas e, principalmente, sobre biofilme foram observadas apenas para o Malvatricin®.

Objective: To evaluate in vitro the antimicrobial potential of Anapyon®, Água Rabelo and Malvatricin® against oral microorganisms.Method: The experiment used a four-day sequential protocol that evaluated by optical density measurements the antimicrobial potential of these products against Staphylococcus aureus, Candida tropicalis, Candida parapsilosis and Candida albicans in their planktonic forms. Only Malvatricin® was also evaluated against microbial biofilms because it was the only one to produce satisfactory results against the planktonic forms. Distilled water was used as negative control and Chlorhexidine® as positive control. The data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests. Results: According to the optical density readings, only Malvatricin® was effective against the planktonic microorganisms and its results were similar to those of the positive control (Chlorhexidine), which is the gold standard antimicrobial agent in dental research. Malvatricin® presented significantly higher efficacy than the other antiseptics (Anapyon® and Água Rabelo®) and the negative control, and this result was similar for all tested microorganisms: S. aureus (p=0.002), C tropicalis (p=0.002), C. parapsilosis (p=0.001) and C. albicans (p<0.001). For this reason, only Malvatricin® was evaluated against the microorganisms arranged as biofilms. Chlorhexidine presented significantly better results (p<0.05) than Malvatricin® against C. albicans and S. aureus. When tested against C. tropicalis, Malvatricin® differed significantly (p<0.05) from distilled water, while against C. parapsilosis no significant difference (p=0.468) was observed in comparison with the negative control. Conclusion: Although some pharmaceutical products being considered anti-microbial, such properties against planktonic cells and especially the biofilms were observed only for Malvatricin®.

Métodos inmunológicos utilizados en la identificación rápida de bacterias y protozoarios en aguas / Immunological methods for the quick identification of bacteria and protozoa in water

Entre las enfermedades relacionadas con el agua según su uso se encuentran las causadas por sustancias químicas y por agentes biológicos. Dentro de estas últimas, las ocasionadas por bacterias y protozoarios patógenos incrementan cada día la lista de enfermedades emergentes y reemergentes. Los métodos de ensayo para la determinación de microorganismos patógenos en el agua no han variado mucho en los últimos años, principalmente para los indicadores bacterianos de contaminación fecal, y por lo general se realizan por métodos convencionales. Sin embargo, existen situaciones, sobre todo en la aparición de brotes de enfermedades, en las que se hace necesario detectar el microorganismo patógeno en agua como posible agente causal, por lo que se ha recomendado el uso de métodos rápidos y confiables. Dentro de estos se encuentran los inmunoensayos, de los cuales los métodos por precipitación y aglutinación, los enzimoinmunoensayos, las técnicas de inmunofluorescencia directa e indirecta y la citometría de flujo son muy útiles en la detección de microorganismos en agua. Mención aparte merece la separación inmunomagnética o inmunocaptura como paso previo a otras técnicas avanzadas. Nos proponemos con este trabajo exponer las ventajas y desventajas de estos métodos, los principios en los cuales se basan y ejemplificar algunos de los más utilizados en microbiología de aguas, así como recalcar su importancia

Diseases related to the use of water may be caused by chemical substances or biological agents. Among the latter, a prominent role is played by pathogenic bacteria and protozoa, which constantly add to the list of emerging and re-emerging diseases. Assay methods to identify pathogenic microorganisms in water have not changed much in recent years, particularly with respect to bacterial indicators of fecal contamination, and tests are usually conducted by conventional methods. However, in certain situations, especially when a disease outbreak occurs, it is necessary to determine what pathogenic microorganism is the possible causal agent, and quick, reliable methods have been recommended to achieve this aim. These include immunoassays, among which precipitation and agglutination methods, enzyme immunoassays, direct and indirect immunofluorescence techniques and flow cytometry have proven very useful to detect microorganisms in water. Special mention should be made of immunomagnetic separation or immunocapture as a step preceding other advanced techniques. The present paper is aimed at presenting the advantages and disadvantages of these methods, as well as the principles on which they are based. Examples are provided of the methods most commonly used in water microbiology, highlighting their importance

La respuesta inmunológica innata y la destrucción del tejido óseo en la enfermedad periodontal: revisión de la literatura / The innate immune response and tissue destruction in periodontal disease bone. A literatura review

La periodontitis desencadena una respuesta inmunológica del huésped contra los microorganismos de la placa dentobacteriana y sus productos. La activación de los receptores Toll-like (TLR) y Nod-like (NLR) en presencia de antígenos bacterianos inducen la respuesta inflamatoria y celular, con la consecuente expresión de citocinas inflamatorias como interleucina 1 (IL-1), interleucina 6 (IL-6), interleucina-8 (IL-8), interleucina 11 (IL-11), interleucina 18 (IL-18) y el factor de necrosis tumoral alfa (TNF-?), así como moléculas antibacterianas como b-defensinas, catelicidina y calprotectina. La IL-1 se asocia con la activación severa de las metaloproteinasas de la matriz extracelular (MMPs) que promueve la perdida de los tejidos de sostén del diente. La IL-6 estimula la diferenciación de los osteoclastos y estimula la síntesis de IL-1. El TNF-? induce la diferenciación de osteoclastos, la resorción ósea y tiene actividad sinérgica con IL-1?. Los neutrófilos forman una barrera entre el epitelio de unión y la placa dentobacteriana cuya función sinérgica es la actividad secretora de especies de oxigeno reactivas y proteínas bactericidas con el mecanismo fagocítico cuya actividad afecta la integridad de los tejidos del periodonto. Los derivados lipídicos del ácido araquidónico como Prostanglandina E2 (PGE2), han sido estrechamente relacionados con la pérdida del hueso alveolar por estimulación de los osteoclastos. Todo esto sugiere que la persistencia de las bacterias, una excesiva respuesta inflamatoria y/o una inadecuada resolución de la inflamación pueden afectar la estructura del tejido óseo durante la enfermedad periodontal.

Periodontitis triggers a host immune response against plaque microorganisms and their products. Activation of Toll-like receptors (TLRs) and Nod-like (NLR) by bacterial antigens triggers an inflammatory response and cell, with the expression of inflammatory cytokines such as interleukin 1 (IL-1), interleukin 6 (IL-6) , interleukin-8 (IL-8), interleukin 11 (IL-11), interleukin 18 (IL-18) and tumor necrosis factor alpha (TNF-?) and antibacterial molecules as b-defensins, cathelicidin and calprotectin . Among the cytokines IL-1? is associated with severe activation of extracellular matrix metalloproteinases (MMPs) that promotes the loss of the tooth-supporting tissues. IL-6 stimulates osteoclast differentiation and stimulates the synthesis of IL-1. TNF-? induces the differentiation of osteoclasts, bone resorption and has synergistic activity with IL-1?. In the cellular response, the neutrophils form a barrier between the junctional epithelium and plaque and secrete reactive oxygen species and bactericidal proteins with the phagocytic mechanism whose activity affects the integrity of the periodontal tissues. Also an arachidonic acid lipid derivative as prostaglandin E2 (PGE2) has been closely related to the loss of alveolar bone by stimulating osteoclast. This suggests that the persistence of bacteria, excessive inflammatory response and / or an inadequate resolution of the inflammation can affect the structure of the bone tissue during periodontal disease.

Are we ready for caries prevention through bacteriotherapy?

Recent insights in medical science indicate that human biofilms play an important role in health and well-being, and have put microbiota modulation through bacteriotherapy into focus. In dentistry, bacterial interference with probiotic bacteria to support the stability and diversity of oral biofilms has gained similar interest. Investigations in vitro into metabolic activity, co-aggregation, growth inhibition, bacteriocin production, and adhesion have collectively suggested a potential role for probiotic lactobacilli and bifidobacteria to modulate the oral microbial ecology. Likewise, short-term clinical studies with intermediate microbial endpoints indicate that interference with caries-associated bacteria seems possible through probiotic dairy products, tablets, lozenges and chewing gum in various dose regimens. Few randomized controlled clinical trials with caries outcomes are available, but three studies with preschool children and the elderly have demonstrated preventive fractions between 21% and 75%, following regular intake of milk supplemented with probiotic lactobacilli. However, further large-scale trials with orally derived anti-caries candidates are needed before we can say that we are ready for bacteriotherapy as an adjunct to complement the existing evidence-based methods for preventing and controlling caries in daily practice.

Tratamento superficial de implantes e sua influência na adesão e viabilidade de células e bactérias: uma revisão / Surface treatment for implants and their influence on the accession and viability of cells and bacteria: a review

O tratamento superficial aplicado aos implantes de titânio tem como principal finalidade acelerar o processo de osseointegração. Inicialmente a única preocupação dos pesquisadores, era como o tratamento aplicado alterava a topografia superficial do titânio. Porém com o tempo, descobriu-se que no que diz respeito aos fatores biológicos, as características químicas influenciam mais que a topografia. Este trabalho teve como objetivo avaliar através de uma revisão da literatura científica, como as alterações dos implantes do titânio podem interferir no processo de adesão e proliferação, tanto de células quanto de bactérias. Alguns estudos demonstram que o tratamento superficial influencia nos primeiros estágios da osseointegração, porém não há um aumento no número de osteoblastos, mas sim uma alteração no padrão de adesão celular. E no que diz respeito aos fatores biológicos, as características químicas influenciam mais que as características topográficas tanto para células quanto para bactérias

The surface treatment applied to titanium implants whose main purpose is to accelerate the process of osseointegration. Initially the only concern of the researchers was how this processaltered the surface topography of titanium. But with time, it was discovered that biological andchemical characteristics influence topography the most. This study aimed to evaluate through a review of scientific literature how the changes of titanium implants can interfere with the process of adhesion and proliferation of both cells and bacteria. Some studies show that the surface treatment influences the early stages of osseointegration however there is an increase in the number of osteoblasts but a change in the pattern of cell adhesion. And concerning to the biological area, chemical characteristics influence the topographic features for both cells and bacterian the most

Culture- and antigen-negative meningitis in Guatemalan children / Meningitis negativa a pruebas antigénicas y de cultivo en niños guatemaltecos

OBJECTIVE: To compare children with confirmed bacterial meningitis (CBM) and those with culture- and latex-negative meningitis (CLN). METHODS: Children 1 to 59 months of age admitted to three major referral hospitals in Guatemala City with clinical signs compatible with bacterial infections were evaluated prospectively between 1 October 1996 and 31 December 2005. Bacterial cultures and latex agglutination antigen testing were performed on samples of cerebrospinal fluid (CSF). RESULTS: The case-fatality rate was significantly higher in the 493 children with CBM than in the 528 children with CLN (27.6 percent and 14.9 percent, respectively; P < 0.001). Children with CBM were less likely to have received antibiotics and more likely to have seizures, shock, or coma on admission than children with CLN. Among the 182 CBM survivors and 205 CLN survivors studied between October 2000 and December 2005, clinically observed sequelae were present at discharge in a higher percentage of the CBM than of the CLN group (78.6 percent and 46.8 percent, respectively; P < 0.0001). CSF glucose < 10 mg/dL, peripheral neutrophils < 2 000 cells/mm³, coma or shock at admission, and concurrent sepsis or pneumonia were risk factors for mortality in children with CBM; only coma or shock at admission predicted mortality in children with CLN. CONCLUSIONS: The high case-fatality and sequelae rates suggest that many children with CLN may have had bacterial meningitis. Estimates based on confirmed meningitis alone underestimate the true vaccine-preventable disease burden. Additional studies to determine etiologies of CLN in this population are indicated.

OBJETIVO: Comparar los casos infantiles de meningitis bacteriana confirmada (MBC) y meningitis negativa a pruebas de látex y de cultivo (MNLC). MÉTODOS: Se evaluaron los niños de 1 a 59 meses de edad ingresados en tres grandes hospitales de referencia de la Ciudad de Guatemala entre el 1 de octubre de 1996 y el 31 de diciembre de 2005 con signos clínicos de infección bacteriana. Se realizaron cultivos bacterianos y pruebas de aglutinación antigénica con látex en muestras de líquido cefalorraquídeo (LCR). RESULTADOS: La tasa de letalidad fue significativamente mayor en los 493 niños con MBC que en los 528 niños con MNLC (27,6 por ciento y 14,9 por ciento, respectivamente; P < 0,001). Los niños con MBC tuvieron menor probabilidad de recibir antibióticos y mayor de sufrir convulsiones, choques o entrar en coma al ser ingresados que los niños con MNLC. Se observó un mayor porcentaje de manifestaciones clínicas de secuelas al alta hospitalaria en los 182 niños sobrevivientes con MBC que en los 205 sobrevivientes con MNLC estudiados entre octubre de 2000 y diciembre de 2005 (78,6 por ciento y 46,8 por ciento, respectivamente; P < 0,0001). Los factores de riesgo de muerte en los niños con MBC fueron: glucosa en LCR < 10 mg/dL, neutrófilos periféricos < 2 000 células/mm³, coma o choque al ingreso, y sepsis o neumonía concurrentes; solo el coma y el choque al ingreso predijeron la muerte en niños con MNLC. CONCLUSIONES: Las altas tasas de letalidad y de secuelas indican que muchos niños con MNLC pueden haber tenido meningitis bacteriana. Las estadísticas basadas solamente en los casos confirmados de meningitis subestiman la verdadera carga de enfermedad prevenible mediante vacuna. Se deben emprender estudios adicionales para determinar las etiologías de la MNLC en esta población.

Superantigenos: una particular interaccion entre microorganismos y el sistema inmune / Superantigens: a particular interaction between microorganisms and the immune system

El descubrimiento de los superatígenos (SAgs) aportó nuevos conceptos en el estudio de las interacciones entre los microorganismos y el sistema inmune. Se trata de moléculas que, asociadas a las de Clase II del Complejo Mayor de Histocompatibilidad (CMH), se unen al dominio variable de la cadena Beta Vbeta) del receptor de antígenos Ags) de los linfocitos T alphaBeta (TCRalphaBeta) que les confiere la especialidad de familia. Así, los SAgs son capaces de activar a un alto número de linfocitos T y de células portadoras de las moléculas de Classe II del CMH, generando una masiva liberación de linfoquinas y mediadores inflamatorios que ha sido relaciona con sus efectos tóxicos. Los SAgs endógenos están codificados por los provirus de tumores murinos (Mtv) que se hallan integrados al genoma de los ratones. Los exógenos son producidos por bacterias y virus, siendo los mejor caracterizados los relacionados con las intoxicaciones alimentarias. Aun no se han hallado datos concluyentes en cuanto a la existencia de SAgs de parásitos y se requieren estudos más detallados para establecer su presencia y posible efecto en las infecciones parasitarias.

Bacterial translocation and wasting in stressed mice

The effects of strees immunity and on the bacterial translocation from intestine to mesenteric lymph nodes, liver, and spleen were studied in a group of newborn CD1 mice. Animals were separated into three experimental groups. Mice from group I were stressed by intraperitoneal (IP) injections of heatkilled staphylococci for 4 weeks. Mice from group II were IP injected with saline solution only. The remaining mice, group III, were not injected. The clinical condition, presence of bacteria in abdominal organs, mitochondrial activity in splenic cells, lymphocyte proliferative response to Concanavalin-A and in vitro antibody production were evaluated in each mouse. Results showed that prolonged IP stressor challenge causes severe weight loss and immunodeficiency. The splenic lymphocytes from stressed mice exhibited a significant depression of both proliferative response to Concanavalin-A stimulation and anti-erythrocytes antibody synthesis. Instead, cultured in basal conditions, the splenic cells from stressed mice have an increased capacity to reduce the tetrazolium salts. Bacterial dissemination from intestine to mesenteric lymphoid nodes was also confirmed in the same group of mice. In contrast, mice in groups II and III presented no weight loss and immunodeficiency. Results suggest that chronic biological stress induced in newborn mice could facilitate the translocation of Gramnegative bacteria. Probable pathogenic mechanisms are commented upon and a correlation is proposed between the bacterial dissemination and the wasting development

Reactivity of the CD D-1 latex test with Clostridium difficile and other bacteria.

The reactivity of a commercial latex test with thirty-three species of bacteria was tested. Toxigenic and nontoxigenic strains of Clostridium difficile gave a positive result in the CD D-1 latex test. Cross-reactions were also given by C. putrificum, C. sporogenes and proteolytic C. botulinum.

Tropical myositis. A clinical immunological and histopathological study.

Thirty cases of tropical myositis, (22 suppurative, 8 non-suppurative) aged 11 to 65 years were seen in a period of one year. There were 22 males and 8 females. There was a total of 78 muscular lesions in 22 suppurative cases and 19 muscular lesions in 8 non-suppurative cases. The most common presentation was localised myalgia (100%), fever (96.7%) generalized myalgia (56.7%), arthralgia (40%), pain in abdomen (33.3%) and breathlessness (30%). Extramuscular complications were present in 50% cases. Twenty four muscle biopsies were taken. Sixteen showed changes of suppurative myositis i.e. non-specific acute inflammatory reaction, muscle necrosis with myocytolysis, vacuolation of cytoplasm and loss of striations. Cell mediated immunity was found to be suppressed in patients of non-suppurative myositis in comparison with the suppurative group. IgG, IgA and IgM were significantly raised in patients in comparison to controls (p less than 0.05). The intact humoral immunity indicates good response to acute phase reaction and increased levels of IgG, IgA and IgM (specially IgG) can be taken as good prognostic parameter.

Bactericidal power of neutrophils in protein calorie malnutrition.

The present study was undertaken to compare the disturbance in bactericidal power of neutrophils in 25 children having protein caloric malnutrition age and sex matched healthy control subjects. There was a highly significant reduction in the percentage of bacteria killed during incubation in children having PCM as compared to healthy control. A direct relationship existed between total serum proteins and bactericidal activity of neutrophils in children having PCM. The impaired bactericidal power of neutrophils can be attributed to impaired synthesis of lysosomal enzymes, glycolytic activity of neutrophils in children having PCM. The exact mechanisms still remain to be elucidated. Decreased bactericidal activity of neutrophils may be one of the mechanisms responsible for infection.