Disbiosis bacteriana y su efecto en enfermedades bucales: una revisión bibliográfica / Bacterial dysbiosis and its effect on oral diseases: a review bibliographic

Objetivo: actualizar la información sobre la disbiosis bacteriana oral y su efecto en enfermedades bucales. Material y métodos: se realizó una revisión bibliográfica detallada, donde la búsqueda de artículos comenzó desde el 2014 con trabajos de investigación relacionados con el tema. Se aplicaron palabras clave para facilitar y delimitar el tema. En los resultados obtenidos se observa información específica de disbiosis bacteriana y los problemas y enfermedades que causan en la cavidad bucal. Conclusión: la cavidad oral es un ecosistema muy complejo e interactivo donde se desarrollan variedades de hábitats que establecen relaciones entre los microorganismos en los distintos medios bucales. Por lo general, el cuerpo humano vive en simbiosis con dichas bacterias, esta relación hospedador-huésped es producto de años de evolución y convivencia para poder tolerar a dichas especies y por medio de años de investigación, determinar a los agentes patógenos y a los simbióticos, lo que permitirá en un futuro tener enfoques terapéuticos y científicos, para así solucionar, mejorar y evitar problemas relacionados con la salud (AU)

Objective: this review aimed to update the information on oral bacterial dysbiosis and its effect on oral diseases. Material and methods: a detailed literature review was performed, where the search for articles began in 2014 with research papers related to the topic. Keywords were applied to facilitate and delimit the topic. The results obtained show specific information on bacterial dysbiosis and the problems and diseases they cause in the oral cavity. Conclusion: the oral cavity is a very complex and interactive ecosystem where a variety of habitats develop and establish relationships between microorganisms in different oral environments. Generally, the human body lives in symbiosis with these bacteria, this host-guest relationship is the product of years of evolution and coexistence to be able to tolerate these species and through years of research to determine the pathogens and symbiotics, which will allow in the future to have therapeutic and scientific approaches, to solve, improve and avoid health-related problems (AU)

Reverse vaccinology and subtractive genomics approaches for identifying common therapeutics against Mycobacterium leprae and Mycobacterium lepromatosis

Mycobacterium leprae and Mycobacterium lepromatosis are gram-positive bacterial pathogens and the causative agents of leprosy in humans across the world. The elimination of leprosy cannot be achieved by multidrug therapy alone, and highlights the need for new tools and drugs to prevent the emergence of new resistant strains. Methods In this study, our contribution includes the prediction of vaccine targets and new putative drugs against leprosy, using reverse vaccinology and subtractive genomics. Six strains of Mycobacterium leprae and Mycobacterium lepromatosis (4 and 2 strains, respectively) were used for comparison taking Mycobacterium leprae strain TN as the reference genome. Briefly, we used a combined reverse vaccinology and subtractive genomics approach. Results As a result, we identified 12 common putative antigenic proteins as vaccine targets and three common drug targets against Mycobacterium leprae and Mycobacterium lepromatosis. Furthermore, the docking analysis using 28 natural compounds with three drug targets was done. Conclusions The bis-naphthoquinone compound Diospyrin (CID 308140) obtained from indigenous plant Diospyros spp. showed the most favored binding affinity against predicted drug targets, which can be a candidate therapeutic target in the future against leprosy.(AU)

Breast abscess due to Trueperella bernardiae and Actinotignum sanguinis / Absceso mamario debido a Trueperella bernardiae y Actinotignum sanguinis

No disponible

Meningitis bacteriana por Streptococcus pyogenes / Bacterial meningitis caused by Streptococcus pyogenes

No disponible

Filifactor alocis: The Newly Discovered Kid on the Block with Special Talents.

Infection-induced periodontal disease has been primarily focused on a small group of periodontal pathogens. A paradigm shift, based on data emerging from the oral microbiome project, now suggests the involvement of as-yet-unculturable and fastidious organisms. Collectively, these studies have demonstrated that there are changes in the periodontal status associated with shifts in the composition of the bacterial community in the periodontal pocket. In addition, it is likely that the emerging new pathogens may play a more significant role in the disease. One of the organisms previously unrecognized is Filifactor alocis. While this Gram-positive anaerobic rod has been identified in peri-implantitis, in endodontic infections, and in patients with localized aggressive periodontitis, its presence is now observed at significantly higher levels in patients with adult periodontitis or refractory periodontitis. Its colonization properties and its potential virulence attributes support the proposal that F. alocis should be included as a diagnostic indicator of periodontal disease. Moreover, these emerging characteristics would be consistent with the polymicrobial synergy and dysbiosis (PSD) periodontal pathogenesis model. Here, unique characteristics of F. alocis are discussed. F. alocis has specific factors that can modulate multiple changes in the microbial community and host cell proteome. It is likely that such variations at the molecular level are responsible for the functional changes required to mediate the pathogenic process.

Linezolid more efficacious than vancomycin to eradicate infecting organism in critically ill patients with Gram-positive infections

Objetivo: Se realizó un estudio prospectivo y observacionalcon el objetivo de analizar la eficacia de linezolid comparadocon vancomicina para erradicar los organismos infectantesen los pacientes críticos con infecciones por grampositivos.Pacientes y Métodos: Estudio prospectivo, observacional yno controlado en una unidad de cuidados intensivos (UCI) deun hospital universitario. Se estudiaron un total de 53 pacientescríticos con tratamiento para una infección bacteriana probaday producida por grampositivos. Los pacientes infectadosfueron diagnosticados y tratados siguiendo las guías internacionalesy los protocolos estándares locales establecidos paralas infecciones de los pacientes críticos. Se analizó la erradicaciónmicrobiológica del organismo infectante al séptimo día detratamiento y la evolución clínica.Resultados: Veintisiete pacientes recibieron tratamientocon linezolid y veintiséis recibieron vancomicina. Los focos infecciososfueron: neumonía adquirida en el hospital (21 casos:39.6 %), infección quirúrgica complicada (19 casos: 35.8 %) ybacteriemia relacionada con el catéter (13 casos: 24.5 %). Elmicroorganismo más frecuentemente aislado fue Staphylococcusaureus (SARM) (28 casos: 52.8 %). El éxito clínico seobtuvo en 20/27 pacientes (74.1 %) en el grupo de linezolid y en 16/26 pacientes (61.5 %) en el grupo de vancomicina, conuna p = 0.3. El modelo de regresión logística mostró que el tratamientocon linezolid se asoció de forma significativa a unaerradicación microbiológica del organismo infectante al séptimodía de tratamiento [OR = 7.88 (95 % CI 1.86-33.52)], p =0.005. En este modelo, la estancia en el hospital fue más bajaen el grupo de pacientes con erradicación microbiológica alséptimo día, (p = 0.015). Los efectos adversos observados fueronsimilares en ambos grupos de tratamiento...(AU)

Objetive: A prospective and observational study hasbeen conducted to analyze the efficacious of linezolidcompared to vancomycin to eradicate the infecting organismin critically ill patients with Gram-positive infections.Patients and Methods: Prospective, observationaland non-controlled study in a medical-surgical intensivecare unit (ICU) in a university hospital. A total numberof 53 critically ill patients with therapy to proven Grampositivebacterial infection were studied. Infected patientswere diagnosed and treated according to internationalguidelines, following standard protocol for thecritically ill infected patients. Microbiologic eradicationof the infecting organism at the seventh day of treatmentand patients’ clinical outcome were analysed.Results: Twenty-seventh patients received linezolidand twenty-six received vancomycin. Infection-site diagnoseswere: hospital-acquired pneumonia (21 cases:39.6%), complicated surgical-site infection (19 cases:35.8%) and catheter-related bacteraemia (13 cases: 24.5%).The most important isolated microorganism was methicillin-resistant Staphylococcus aureus (MRSA) (28 cases:52.8%). Clinical success was 20/27 (74.1%) in the linezolidgroup and 16/26 (61.5 %) in the vancomycin group, with p= 0.3. The adjusted logistic regression model demonstratedthat the treatment with linezolid is associated to microbiologiceradication of the infecting organism at the seventhday of treatment [OR = 7.88 (95% CI 1.86-33.52)] and p =0.005. In this model, the length of hospital stay was lowerin the group with microbiologic eradication at the seventhday (p = 0.015). Drug-related adverse events were comparablein both groups of treatment...(AU)

Heterorresistencia y tolerancia a glucopéptidos en aislados grampositivos en el hospital: ¿fenómenos "invisibles" para el clínico con posible traducción clínica? / Glycopeptide heteroresistance and tolerance in hospital grampositive isolates: "invisible" phenomena to the clinician with clinical implications?

En este artículo se revisan los fenómenos de heterorresistenciay tolerancia a los glucopéptidos en grampositivos aisladosde pacientes hospitalizados. La heterorresistencia (subpoblacionesresistentes, dentro de la población bacteriana totalde la cepa, seleccionables por el tratamiento) y la tolerancia(capacidad de sobrevivir pero no crecer en presencia de concentracionesantibióticas normalmente letales) tienen en comúnvarias características: 1) la ausencia de su determinaciónen rutina por parte del laboratorio, 2) implican una disminuciónde la actividad antimicrobiana que no queda reflejada enel valor de la CMI (por lo que es “invisible” para el clínico en losinformes del laboratorio en la rutina diaria), 3) la disminuciónde la actividad antimicrobiana puede tener implicaciones clínicasy 4) afectan a un amplio espectro de grampositivos en elhospital (Staphylococcus aureus, estafilococos coagulasa-negativo,enterococos y distintas especies de estreptococos). Eldecremento de la actividad bactericida (absolutamente necesariaen bacteriemias, endocarditis, meningitis e infecciones enel paciente inmunocomprometido) se traduce como persistenciade la bacteriemia, bacteriemia refractaria al tratamientocon glucopéptidos, recurrencia de la infección y aumento de laestancia hospitalaria. Dos estrategias son posibles para contrarrestarestos fenómenos: adición de antibióticos que medianteel sinergismo (requisito indispensable por lo que hay que teneren cuenta las combinaciones antagónicas o el fenómeno de altaresistencia a aminoglucósidos) consigan actividad bactericida,o utilización de compuestos bactericidas frente a los cualeslos grampositivos presenten sensibilidad y ausencia de heterorresistenciay tolerancia (a diferencia de los glucopéptidos), comoes el caso del lipopéptido daptomicina(AU)

This article reviews the concepts of heteroresistanceand tolerance to glycopeptides in gram-positive bacteriaisolated from hospitalised patients. Heteroresistance (resistantsubpopulations among the total bacterial populationof the strain, that can be selected by the treatment)and tolerance (capability of survival, but not growth, inthe presence of usually lethal antibiotic concentrations)have in common several characteristics: 1) the absenceof its determination in laboratory daily practice, 2) theyimplied a decrease in antimicrobial activity not reflectedin MIC values (thus being “invisible” to clinicians in dailyroutine laboratory reports), 3) the decrease in antimicrobialactivity may have clinical implications and 4)they affect a wide spectrum of gram positive bacteria inthe hospital (Staphylococcus aureus, coagulase-negativestaphylococci, enterococci and different estreptococcalspecies). The decrease produced in the bactericidal activity(that is critical for the treatment of bacteremias, endocarditis,meningitis and infections in immunocompromisedpatients) has clinical implications such aspersistance of bacteremia, refractory bacteremia, relapseof infections and increased length of stay. Two strategiesare possible to overcome tolerance and heteroresistance:addition of antibiotics to obtain bactericidal activity bysynergism (key factor for which it should be taken intoaccount antagonic combinations or high resistance toaminoglycosides when choosing the antibiotic regimen),or the use of bactericidal compounds to which grampositivebacteria show susceptibility and absence of heteroresistanceand tolerance (in contrast to glycopeptides),as is the case of lipopeptide daptomycin(AU)

Actividad in vitro de fosfomicina frente a enterobacterias de origen urinario productoras de betalactamasas de espectro extendido / In vitro activity of fosfomycin against ESBL-producing enterobacteria of urinary origin

Se ha determinado la actividad in vitro de fosfomicina,comparada con otros antimicrobianos de uso urinario, frentea aislamientos clínicos de Escherichia coli y Klebsiellapneumoniae de origen urinario productores de betalactamasasde espectro extendido (BLEE). Se estudió mediantedilución en agar o E-test la actividad de fosfomicina, cotrimoxazol,ciprofloxacino, nitrofurantoína, amoxicilina/clavulánicoy gentamicina frente a 71 cepas de E. coli y 13 deK. pneumoniae de origen urinario y productoras de BLEE. Lascepas de E. coli producían sobre todo BLEE de tipo CTX-M(76,1%), y principalmente CTX-M 14 (56,3%). Las cepas de K.pneumoniae produjeron casi exclusivamente enzimas tipoSHV (92,3 %), prevaleciendo SHV-2 (76,9 %). Gentamicina(4,4 %), fosfomicina (5,6 %) y nitrofurantoína (5,6%) mostraronlos menores porcentajes de resistencia en E. coli. Cotrimoxazoly ciprofloxacino (7,7%) mostraron los porcentajesde resistencia más bajos en K. pneumoniae (AU)

In vitro activity of fosfomycin, compared with otherantibiotics used for urinary tract infections (UTI), againstextended spectrum beta-lactamase (ESBL)-producing Escherichiacoli and Klebsiella pneumoniae clinical isolatesobtained from UTIs, was determined. The activity of fosfomycin,co-trimoxazole, ciprofloxacin, nitrofurantoin,amoxicillin/ clavulanic acid and gentamicin against 71ESBL-producing E. coli clinical isolates and 13 ESBLproducingK. pneumoniae clinical isolates obtained from UTI was studied by the agar-dilution method or E-test. E.coli isolates produced mainly CTX-M type ESBL (76.1%),especially CTX-M 14 (56.3 %). K. pneumoniae isolatesproduced most predominantly SHV-type ESBL (92.3%),mainly SHV-2 (76.9 %). Gentamicin (4.4 %), fosfomycin(5.6 %) and nitrofurantoin (5.6 %) showed the lowest resistanceproportions against E. coli. Co-trimoxazole andciprofloxacin (7.7 %) showed the lowest resistance proportionsagainst K. pneumoniae (AU)

Experiencia clínica con tigeciclina en el tratamiento de infecciones nosocomiales producidas por aislados con mecanismos de resistencia prevalentes / Clinical experience with tigecycline in the treatment of nosocomial infections caused by isolates exhibiting prevalent resistance mechanisms

Este artículo incluye una revisión de la experiencia clínicacon tigeciclina en infecciones por microorganismos con losfenotipos de resistencia más prevalentes en la microbiotanosocomial, como Staphylococcus aureus resistente a lameticilina y enterococos resistentes a la vancomicina dentrode los gram positivos, y Acinetobacter baumannii multirresistentey enterobacterias productoras de betalactamasasde espectro extendido dentro de los gram negativos nosocomiales.La mayoría de los artículos encontrados en la literaturadescriben la utilización de la tigeciclina en el tratamientode infecciones graves (sepsis y shock séptico,neumonía nosocomial y neumonía asociada a ventilaciónmecánica, etc.) producidas por estos microorganismos multirresistentes,en pacientes que presentan comorbilidadesgraves (pacientes ingresados en la unidad de cuidados intensivos(UCI), oncológicos, inmunodeprimidos, etc.) y enmuchas ocasiones tras el fracaso de otros tratamientos. Apesar de estas circunstancias, tigeciclina presenta unos datosde eficacia favorables. Hacer una evaluación global precisaresultaría muy difícil, ya que aparte de los factores deconfusión descritos, se añade la presencia de tratamientosantibióticos concomitantes o secuenciales, así como la faltaen algunas comunicaciones de datos clínicos (como comorbilidades),microbiológicos (como sensibilidad antibiótica) yde respuesta terapéutica (como criterios de valoración distintospor distintos autores) relevantes. Por otra parte lasseries son retrospectivas sin grupo control (AU)

This article reviews the clinical experience with tigecyclinein the treatment of infections caused by microorganismswith prevalent resistance mechanisms amongnosocomial microbiota, as methicillin-resistant Staphylococcusaureus, vancomycin-resistant enterococci, multidrug-resistant Acinetobacter baumannii and enterobacteriaproducing extended spectrum ß-lactamases. Mostof articles found in the literature describe the use of tigecyclinein the treatment of severe infections (sepsisand septic shock, nosocomial pneumonia and ventilador-associated pneumonia…) produced by multidrug-resistantmicroorganisms, in patients with multiple comorbidities(admitted in ICU, with malignancies, transplantsand/or immunodepressed…) and in many occasions afterfailures of previous antibiotic treatments. Favourableoutcomes with tigecycline are reported in most articles.However, an accurate global assessment is difficult since,in addition to the described confounding factors, thereare concomitant or sequential antibiotic treatments inseveral communications, and lack of relevant clinical (ascomorbidities), microbiological (as susceptibility) andoutcome (different criteria by different authors) data inothers. More even, the described series are retrospectiveand lack of control groups. Nevertheless the usefulnessof this revision is based on the fact that in daily clinicalpractice the use of tigecycline will increase, since epidemiologyof specific hospital medical units shows multidrugresistance among nosocomial isolates and tigecy cline can be one of the scarce available compounds activeagainst multidrug-resistant strains/clones (AU)

Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

AIMS: To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. METHODOLOGY: Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). RESULTS: In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). CONCLUSIONS: Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.

Oral flora and pathogenic organisms.

Oral microbial flora consist of numerous bacterial taxa, ranging from aerobes through fastidious anaerobes, and fungi, viruses, and protozoa. Many of these bacteria are unique to the oral cavity. The organisms exist in a complex interrelationship that is regulated and maintained by physical and metabolic microbial interactions, and by environmental factors, such as saliva and diet. Many of these organisms are relatively harmless, although others are significant pathogens, producing local and systemic diseases in healthy and compromised individuals.

Enfermedad de Whipple: caso clínico y revisión bibliográfica / Whipple's disease: case report and bibliographic review

Se presenta un caso de enfermedad de Whipple confirmado, en una mujer de 61 años, por estudio histológico de biopsias escalonadas de duodeno y yeyuno.Se señala la etiología bacteriana y el carácter sistémico de la afección, que es producida por la Tropheryma whippelii, que es un bacilo Gram positivo con forma de hoz. Se describe el cuadro clínico que es esencialmente polimorfo pero dentro del cual destacan la diarrea crónica de tipo alto, con caracteres de síndrome de malabsorción y marcado compromiso progresivo del estado general; las artralgias y poliartritis y la fiebre. La enfermedad responde favorablemente a diversos antibióticos que deben administrarse en forma prolongada para intentar reducir las recurrencias que son muy frecuentes y que comprometen muchas veces al sistema nervioso central

Role of bacteria in the pathogenesis of short bowel syndrome-associated D-lactic acidemia.

Previously, we have demonstrated that short bowel syndrome (SBS) patients suffer daily from D-lactic acidemia; in these patients rather high amounts of (bacterial) D-lactate emerge in blood and urine with a circadian rhythm. The aim of this study was to establish the microbial basis of D-lactic acidemia in SBS. Therefore, faecal flora of (young and adult) SBS-patients was analysed qualitatively and quantitatively, and compared to that of controls. The isolated bacterial species were screened for massive D- and/or L-lactate production after in vitro growth. After introduction of oral feeding in SBS-infants shortly after the resection, lactobacilli increased from < or = 1% up to 60 +/- 5% of the faecal flora within 2-3 weeks. In the faeces of patients with oral feeding the lactate producers Lactobacillus acidophilus and Lactobacillus fermentum were the major resident bacteria (each with 10(10)-10(12) cfu/g faeces). During active growth in vitro these lactobacilli produced massive amounts of D- and L-lactic acid from glucose. Use of oral antibiotics in two SBS-children did not reduce the total numbers of lactobacilli, but caused shifts within the intestinal populations of at least lactobacilli. It is concluded that the strongly reduced intestinal capacity for carbohydrate absorption and the oral consumption of easily fermentable carbohydrates form the physiological basis for D-lactic acidemia in SBS, and that the fermentative D-lactate production by intestinal bacteria, especially the abundant, resident lactobacilli, forms its microbial basis. In these patients the antimicrobial and therapeutic effects of antibiotics are unpredictable.

Doença de Whipple / Whipple's Disease

A Doença de Whipple é uma doença bacteriana sistêmica rara, com maior incidência entre a quarta e sexta décadas, no sexo masculino e na raça caucasiana. Cursa com infiltraçäo por macrófagos com grânulo PAS positivos nos órgäos e tecidos afetados. O microrganismo responsável é o bacilo gram-positivo intracelular Tropheryma whippelli. Relata-se o caso de paciente masculino, 53 anos, branco, quadro clínico compatível com doença má-absortiva, cujo diagnóstico foi realizado através da esôfago-gastroduodenoscopia com presença de papilite e duodenite serveras, onde a biópisa evidenciou os grânulos PAS positivos infiltrando a lâmina própria do intestino delgado. Após 3 meses de tratamento com sulfametoxazol e trimetroprim, apresenta-se assintomático e com ganho ponderal satisfatório. Como os sintomas da DW säo inespecíficos é importante a realizaçäo de diagnóstico diferencial com outras doenças má-absortivas(doença celíaca, doença de Crohn, linfoma intra-abdominal, SIDA)

Case of fatal systemic infection with an Aureobacterium sp.: identification of isolate by 16S rRNA gene analysis.

The case of a 75-year-old man who succumbed to a disseminated infection most likely caused by a species of the genus Aureobacterium is reported. Identification of the isolate was achieved by comparative 16S rRNA gene analysis. Aureobacteria are commonly found in the environment. However, only recently have they been recognized as a cause of infections including septicemia and soft tissue infections. To our knowledge, this is the first documentation of a fatal infection caused by an Aureobacterium sp.