Short-term effect of removal of fixed orthodontic appliances on gingival health and subgingival microbiota: a prospective cohort study.

OBJECTIVE: The aim of this prospective longitudinal study was to assess and compare the microbiological and clinical parameters of patients wearing a fixed orthodontic appliance, as opposed to 10 days after the bracket had been removed following treatment. MATERIALS AND METHODS: In total, 122 patients participated in this study; 61 of the subjects were assessed at baseline (wearing a fixed orthodontic appliance: T1) and 10 days after bracket removal (T2). The other 61 individuals had never worn an orthodontic appliance before and these subjects served as controls (CT). Subgingival plaque samples were assessed for bleeding on probing (GBI) and plaque index (VPI). PCR of 16s rDNA, followed by reverse species-specific hybridization for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola were performed. A descriptive analysis was conducted; chi-squared, Student's matched and unmatched t-tests, the point biserial correlation coefficient and the McNemar test were used to test for differences between groups (p < 0.05). RESULTS: The GBI and VPI clinical parameters showed statistical differences (p < 0.05) between T1-T2, T1-CT and T2-CT. The prevalence of T. denticola had significantly decreased (p = 0.039) 10 days after appliance removal. At T2, a significant positive correlation was found between GBI and A. actinomycetemcomitans (p < 0.01) and between clinical parameters and P. intermedia. In patients without a fixed orthodontic appliance (T2 and CT), there was a significant positive correlation between T. forsythia and VPI. CONCLUSION: Local factors associated with the wearing of a fixed orthodontic appliance influence changes in subgingival plaque that leads to more inflammation and bleeding.

Postorthodontic external root resorption in root-filled teeth is influenced by interleukin-1ß polymorphism.

INTRODUCTION: External apical root resorption (EARR) is a frequent iatrogenic effect of orthodontic treatment. The way root-filled teeth respond to orthodontic forces with respect to EARR has been reported as varying widely between individuals. Genetic variants in the interleukin-1 gene have been associated with an increased risk of experiencing postorthodontic EARR on vital teeth. The objective of this study is to determine whether variants in the interleukin-1 gene have a positive or negative influence on EARR on teeth that have been endodontically treated. METHODS: Ninety-three orthodontic patients underwent genetic screening for 2 single nucleotide polymorphisms (rs1800587, rs1143634) in the IL1 gene cluster. Subjects were divided into 2 groups depending on the presence (affected group) or absence (control group) of more than 2 mm of EARR on root-filled teeth after orthodontic treatment as shown by radiography. Logistic regression analysis was used to obtain adjusted estimates of EARR and IL1 polymorphisms. Allele frequencies, genotype distributions, and adjusted odds ratios were also calculated (95% confidence interval). RESULTS: No positive or negative statistical association was found between postorthodontic treatment EARR in root-filled teeth and genetic variations in IL1A (P > .05). A direct relationship was found for the IL1B gene in the comparative analysis of homozygous subjects (2/2[TT]) and (1/1[CC]), which led to an increased risk of experiencing postorthodontic treatment EARR in root-filled teeth (odds ratio = 11.59; P = .006; confidence interval, 95%) and (odds ratio = 2.54; P = .035; confidence interval, 95%), respectively. CONCLUSIONS: The development of EARR in subjects with root-filled teeth who undergo orthodontic treatment might be attributable to genetic variations in the interleukin-1ß gene (rs1143634).

[Comparative in vitro activity of daptomycin against gram-positive microorganisms: SENTRY surveillance program, Spain (2002-2006)]. / Actividad comparativa de daptomicina frente a microorganismos grampositivos: programa SENTRY España (2002-2006).

INTRODUCTION AND OBJECTIVE: Daptomycin is a bactericidal lipopeptide antibiotic, active against gram-positive bacteria. In this study, the comparative in vitro activity of daptomycin and other antimicrobial agents against isolates recovered in 3 Spanish hospitals from 2002 to 2006 was determined as part of the international SENTRY antimicrobial resistance surveillance program. The possible therapeutic role of daptomycin is addressed in the light of Spanish susceptibility data. METHODS: Antimicrobial susceptibility testing was performed by the microdilution method with 1398 consecutively recovered gram-positive isolates. RESULTS: All the staphylococci (n = 1024), enterococci (n = 228), and streptococci (n = 146) studied were susceptible to daptomycin. The highest MIC values were 1, 4, and 0.5 microg/mL, respectively, regardless of methicillin, vancomycin, or penicillin resistance status. All Staphylococcus aureus isolates were also susceptible to vancomycin, teicoplanin, linezolid, and quinupristin-dalfopristin. Coagulase-negative staphylococci were susceptible to vancomycin, linezolid, and quinupristin-dalfopristin. Only daptomycin and linezolid were active against all enterococcal isolates. In addition, vancomycin, teicoplanin, and ampicillin were fully active against Enterococcus faecalis. Daptomycin, vancomycin, teicoplanin, linezolid, and quinupristin-dalfopristin were active against all Streptococcus pyogenes, S. agalactiae, and S. viridans group isolates. The distribution of daptomycin MIC values in S. aureus and enterococci was homogeneously sustained along the 5-year study period. CONCLUSION: The sustained antimicrobial activity of daptomycin against staphylococci, enterococci, and streptococci in Spain makes this antibiotic an excellent therapeutic option in severe infection caused by gram-positive microorganisms, including those with multiresistance.

[Fresh versus pasteurized yogurt: comparative study of the effects on microbiological and immunological parameters, and gastrointestinal comfort]. / Yogures frescos frente a pasteurizados: estudio comparativo de sus efectos sobre los parámetros microbiológicos, inmunológicos y el bienestar gastrointestinal.

OBJECTIVE: To determine whether the beneficial effects of yogurt are dependent on the viability of lactic bacteria and exclusive to fresh yogurt, by comparison with the effects of yogurt that is pasteurized after fermentation. MATERIAL AND METHOD: Using a double-blind design in a healthy adult population over 75 days, we compared the effects of fresh and pasteurized yogurt on microbiological (presence of viable bacteria in yogurt and DNA detection in feces) and immunological (nephelometry, hematometry, and flow cytometry) parameters. A questionnaire was used to assess gastrointestinal comfort. Differences in lactose absorption after ingestion of fresh or pasteurized yogurt were determined by breath hydrogen analysis. RESULTS: There were no significant differences in the results obtained for microbiological or immunological parameters, gastrointestinal comfort, or lactose test between the two types of yogurt ingested. Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) was isolated in 0.7% of the fecal samples analyzed. Streptococcus thermophilus was not found in any sample. DNA from lactic bacteria was detected in only 12.5% of the samples analyzed. CONCLUSION: Transit through the gastrointestinal tract affects survival of L. bulgaricus and S. thermophilus. No differences were found in the immunological parameters, gastrointestinal comfort, or lactose overload after intake of fresh or pasteurized yogurt.

Yogures frescos frente a pasteurizados: estudio comparativo de sus efectos sobre los parámetros microbiológicos, inmunológicos y el bienestar gastrointestinal / Fresh versus pasteurized yogurt: comparative study of the effects on microbiological and immunological parameters, and gastrointestinal comfort

OBJETIVO. Determinar si los efectos beneficiosos del yogur dependen de la viabilidad de las bacterias lácticas y son exclusivos de los yogures frescos, en comparación con los obtenidos de los yogures pasteurizados tras la fermentación. MATERIAL Y MÉTODO. Mediante un ensayo enmascarado en una población adulta sana y durante 75 días, comparamos los efectos de la ingestión de yogures frescos y pasteurizados sobre los parámetros microbiológicos(presencia de bacterias vivas del yogur y detección de ADN en heces) e inmunológicos (mediante nefelometría, hematimetría y citometría de flujo). Con un cuestionario se evaluó el bienestar gastrointestinal y se utilizó una prueba de aliento para medir las diferencias en un ensayo de sobrecarga de lactosa tras el consumo de yogures. RESULTADOS. No hubo diferencias significativas entre los resultados obtenidos para los parámetros inmunológicos, bienestar gastrointestinal y sobrecarga de lactosa de los voluntarios tras el consumo de yogures, con independencia del tipo de yogur ingerido. Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) sólo se aisló en el 0,7% de las muestras de heces analizadas. Streptococcus thermophilus no se aisló en ninguna de las muestras. EL ADN de las bacterias lácticas del yogur sólo fue detectado en el 12,5% de las muestras analizadas. CONCLUSIÓN. El tránsito gástrico afectó a la supervivencia de L. bulgaricus y S. thermophylus. No se encontraron diferencias respecto a los efectos que la ingestión de yogures frescos o pasteurizados pudieran tener sobre los parámetros inmunológicos, los valores de las pruebas desobrecarga de lactosa, ni sobre el bienestar gastrointestinal (AU)

OBJECTIVE. To determine whether the beneficial effects of yogurt are dependent on the viability of lactic bacteria and exclusive to fresh yogurt, by comparison with the effects of yogurt that is pasteurized after fermentation. MATERIAL AND METHOD. Using a double-blind design in a healthy adult population over 75 days, we compared the effects of fresh and pasteurized yogurt on microbiological(presence of viable bacteria in yogurt and DNA detection in feces) and immunological (nephelometry, hematometry, and flow cytometry) parameters. A questionnaire was used to assess gastrointestinal comfort. Differences in lactose absorption after ingestion of fresh or pasteurized yogurt were determined by breath hydrogen analysis. RESULTS. There were no significant differences in the results obtained for microbiological or immunological parameters, gastrointestinal comfort, or lactose test between the two types of yoghourt ingested. Lactobacillusdelbrueckii ssp. bulgaricus (L. bulgaricus) was isolated in 0.7% of the fecal samples analyzed. Streptococcusthermophilus was not found in any sample. DNA from lactic bacteria was detected in only 12.5% of the samples analyzed. CONCLUSION. Transit through the gastrointestinal tract affects survival of L. bulgaricus and S. thermophilus. Nodifferences were found in the immunological parameters, gastrointestinal comfort, or lactose overload after intake of fresh or pasteurized yogurt (AU)

Actividad comparativa de daptomicina frente a microorganismos grampositivos: programa SENTRY España (2002-2006) / Comparative in vitro activity of daptomycin against gram-positive microorganisms: SENTRY surveillance program, Spain (2002-2006)

Introducción y objetivo. La daptomicina es un antibiótico lipopeptídico bactericida frente a microorganismos grampositivos. En este trabajo estudiamos la actividad in vitro de daptomicina comparativamente con otros antibióticos frente a aislados de tres hospitales españoles recogidos durante el período 2002-2006, en el marco del programa internacional de vigilancia de la resistencia, SENTRY, para establecer sus posibilidades terapéuticas con datos específicos de España. Métodos. Los antibióticos se estudiaron por la técnica de microdilución frente a 1.398 microorganismos grampositivos aislados consecutivamente. Resultados. Todos los estafilococos (n = 1.024), enterococos (n = 228) y estreptococos (n = 146) fueron sensibles a daptomicina y presentaban valores máximos de concentraciones inhibitorias mínimas (CIM) de 1, 4 y 0,5 mg/ml, respectivamente, con independencia de la resistencia a meticilina, vancomicina o penicilina. Staphylococcus aureus fue también sensible a vancomicina, teicoplanina, linezolid y quinupristina-dalfopristina y los estafilococos coagulasa negativa (SCN) a vancomicina, linezolid y quinupristina-dalfopristina. Frente a enterococos, sólo daptomicina y linezolid fueron activos frente a la totalidad de éstos. Además, vancomicina, teicoplanina y ampicilina fueron totalmente efectivos frente a Enterococcus faecalis. Frente a Streptococcus pyogenes, Streptococcus agalactiae y estreptococos del grupo viridans, daptomicina, vancomicina, teicoplanina, linezolid y quinupristina dalfopristina fueron plenamente activos. La distribución de las CIM de daptomicina a través de los 5 años fue homogénea en S. aureus y enterococos. Conclusión. La actividad de daptomicina frente a estafilococos, enterococos y estreptococos, mantenida a lo largo de los años en España, la convierte en una excelente opción terapéutica en infecciones graves por microorganismos grampositivos, incluyendo los multirresistentes (AU)

INTRODUCTION AND OBJECTIVE. Daptomycin is a bactericidal lipopeptide antibiotic, active against gram-positive bacteria. In this study, the comparative in vitro activity of daptomycin and other antimicrobial agents against isolates recovered in 3 Spanish hospitals from 2002 to 2006 was determined as part of the international SENTRY antimicrobial resistance surveillance program. The possible therapeutic role of daptomycin is addressed in the light of Spanish susceptibility data. METHODS. Antimicrobial susceptibility testing was performed by the microdilution method with 1398 consecutively recovered gram-positive isolates. RESULTS. All the staphylococci (n 1024), enterococci (n 228), and streptococci (n 146) studied were susceptible to daptomycin. The highest MIC values were 1, 4, and 0.5 g/mL, respectively, regardless of methicillin, vancomycin, or penicillin resistance status. All Staphylococcus aureus isolates were also susceptible to vancomycin, teicoplanin, linezolid, and quinupristin-dalfopristin. Coagulase-negative staphylococci were susceptible to vancomycin, linezolid, and quinupristin-dalfopristin. Only daptomycin and linezolid were active against all enterococcal isolates. In addition, vancomycin, teicoplanin, and ampicillin were fully active against Enterococcus faecalis. Daptomycin, vancomycin, teicoplanin, linezolid, and quinupristin-dalfopristin were active against all Streptococcus pyogenes, S. agalactiae, and S. viridans group isolates. The distribution of daptomycin MIC values in S. aureus and enterococci was homogeneously sustained along the 5-year study period CONCLUSION. The sustained antimicrobial activity of daptomycin against staphylococci, enterococci, and streptococci in Spain makes this antibiotic an excellent therapeutic option in severe infection caused by gram-positive microorganisms, including those with multiresistance (AU)

Intracellular penetration and activity of DX-619 in human polymorphonuclear leukocytes.

The intracellular penetration and activity of DX-619 in human polymorphonuclear leukocytes have been evaluated. DX-619 reached intracellular concentrations 10 times higher than the extracellular concentrations reached. Uptake was rapid, reversible, nonsaturable, and affected by environmental temperature, some metabolic inhibitors, and a soluble membrane activator. DX-619 showed intracellular activity against Staphylococcus aureus.

[Epidemiology, clinical features and prognosis of infections due to Stenotrophomonas maltophilia]. / Características epidemiológicas, clínicas y pronósticas de la infección por Stenotrophomonas maltophilia.

INTRODUCTION: Stenotrophomonas maltophilia is a multiresistant pathogen that is being isolated with increasing frequency from patients with predisposing factors. Few studies have assessed the epidemiology and clinical relevance of this pathogen in various types of patients from general hospitals. METHODS: This is a prospective study performed in the cohort of patients with infection due to S. maltophilia in Hospital Univeritario Virgen Macarena (Seville, Spain) between January 1998 and January 2001. The following data were collected: demographics, underlying diseases, APACHE II score at admission, invasive procedures, previous antimicrobial treatment, systemic response, therapy and outcome. RESULTS: S. maltophilia was isolated from a clinical sample in 87 patients and was considered to be the cause of infection in 45 (52%) of them, who were included in the study. Among the total, 40% were in the ICU and 13% were outpatients. The infection was considered health care-associated in 91%; 82% had received antimicrobial treatment. The most frequent type of infection was pneumonia, followed by other infections of the respiratory tract, urinary tract infections, and skin and soft tissue infections. Criteria for severe sepsis or septic shock were present in 12%. The most common antimicrobials used were the combination trimethoprim-sulfamethoxazole (60%). Crude mortality was 44% and the only associated variable was the APACHE II score. Infection-related mortality was 13%; all deaths occurred in patients with pneumonia. CONCLUSION: S. maltophilia caused a wide range of health care-associated infections in debilitated patients, even though half the patients from whom the organism was isolated were considered only colonized. Crude mortality was associated with the severity of the baseline situation. Pneumonia was associated with high mortality.

Características epidemiológicas, clínicas y pronósticas de la infección por Stenotrophomonas maltophilia / Epidemiology, clinical features and prognosis of infections due to Stenotrophomonas maltophilia

Introducción. Stenotrophomonas maltophilia es un patógeno multirresistente que se está aislando con frecuencia creciente de pacientes predispuestos. Hay pocos estudios que hayan evaluado su epidemiología y relevancia clínica en pacientes de un hospital general. Métodos. Estudio prospectivo de la cohorte de casos de infección por S. maltophilia entre enero de 1998 y enero de 2001 en el Hospital Universitario Virgen Macarena de Sevilla. Se recogieron variables demográficas, enfermedades de base, gravedad al ingreso (índice APACHE II), procedimientos invasivos, uso previo de antimicrobianos, repercusión sistémica, tratamiento y mortalidad. Resultados. S. maltophilia se aisló en muestras clínicas de 87 pacientes, de los cuales se incluyeron los 45 casos (52%) en los que se consideró que estaba causando infección. El 40% estaba en unidad de cuidados intensivos (UCI) y el 13% eran ambulatorios. La infección se consideró asociada a la atención sanitaria en el 91%. El 82% habían recibido antibióticos. El tipo de infección más frecuente fue la neumonía seguida de otras infecciones respiratorias, urinarias y de piel y tejidos blandos. Presentaron sepsis grave o shock séptico el 12%. El tratamiento antimicrobiano más utilizado fue trimetoprima-sulfametoxazol (60%). La mortalidad bruta fue del 44%; el único factor asociado a la mortalidad bruta fue el índice APACHE II. La mortalidad atribuible a la infección fue del 13%, y sólo ocurrió en pacientes con neumonía. Conclusión. S. maltophilia causa un amplio espectro de infecciones asociadas a la atención sanitaria en pacientes predispuestos, aunque la mitad de los pacientes en que se aisló se consideraron sólo colonizados. La mortalidad bruta se asocia con la gravedad basal. La neumonía se asocia con elevada mortalidad (AU)

Introduction. Stenotrophomonas maltophilia is a multiresistant pathogen that is being isolated with increasing frequency from patients with predisposing factors. Few studies have assessed the epidemiology and clinical relevance of this pathogen in various types of patients from general hospitals. Methods. This is a prospective study performed in the cohort of patients with infection due to S. maltophilia in Hospital Univeritario Virgen Macarena (Seville, Spain) between January 1998 and January 2001. The following data were collected: demographics, underlying diseases, APACHE II score at admission, invasive procedures, previous antimicrobial treatment, systemic response, therapy and outcome. Results. S. maltophilia was isolated from a clinical sample in 87 patients and was considered to be the cause of infection in 45 (52%) of them, who were included in the study. Among the total, 40% were in the ICU and 13% were outpatients. The infection was considered health care-associated in 91%; 82% had received antimicrobial treatment. The most frequent type of infection was pneumonia, followed by other infections of the respiratory tract, urinary tract infections, and skin and soft tissue infections. Criteria for severe sepsis or septic shock were present in 12%. The most common antimicrobials used were the combination trimethoprim-sulfamethoxazole (60%). Crude mortality was 44% and the only associated variable was the APACHE II score. Infection-related mortality was 13%; all deaths occurred in patients with pneumonia. Conclusion. S. maltophilia caused a wide range of health care-associated infections in debilitated patients, even though half the patients from whom the organism was isolated were considered only colonized. Crude mortality was associated with the severity of the baseline situation. Pneumonia was associated with high mortality (AU)

Clinical and molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli as a cause of nosocomial infection or colonization: implications for control.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing members of the Enterobacteriaceae family are important nosocomial pathogens. Escherichia coli producing a specific family of ESBL (the CTX-M enzymes) are emerging worldwide. The epidemiology of these organisms as causes of nosocomial infection is poorly understood. The aims of this study were to investigate the clinical and molecular epidemiology of nosocomial infection or colonization due to ESBL-producing E. coli in hospitalized patients, consider the specific types of ESBLs produced, and identify the risk factors for infection and colonization with these organisms. METHODS: All patients with nosocomial colonization and/or infection due to ESBL-producing E. coli in 2 centers (a tertiary care hospital and a geriatric care center) identified between January 2001 and May 2002 were included. A double case-control study was performed. The clonal relatedness of the isolates was studied by repetitive extragenic palindromic-polymerase chain reaction and pulsed-field gel electrophoresis. ESBLs were characterized by isoelectric focusing, polymerase chain reaction, and sequencing. RESULTS: Forty-seven case patients were included. CTX-M-producing E. coli were clonally unrelated and more frequently susceptible to nonoxyimino-beta-lactams. Alternately, isolates producing SHV- and TEM-type ESBL were epidemic and multidrug resistant. Urinary catheterization was a risk factor for both CTX-M-producing and SHV-TEM-producing isolates. Previous oxyimino-beta-lactam use, diabetes, and ultimately fatal or nonfatal underlying diseases were independent risk factors for infection or colonization with CTX-M-producing isolates, whereas previous fluoroquinolone use was associated with infection or colonization with SHV-TEM-producing isolates. CONCLUSIONS: The epidemiology of ESBL-producing E. coli as a cause of nosocomial infection is complex. Sporadic CTX-M-producing isolates coexisted with epidemic multidrug-resistant SHV-TEM-producing isolates. These data should be taken into account for the design of control measures.

Uptake and intracellular activity of voriconazole in human polymorphonuclear leucocytes.

OBJECTIVES: The intracellular penetration of voriconazole into human polymorphonuclear leucocytes (PMNs) and its intracellular activity against Candida spp. were evaluated. METHODS: The intracellular penetration of voriconazole into PMNs was evaluated by a radiometric assay. The effect of cell viability, environmental conditions, metabolic inhibitors and membrane stimulation was also studied. The intracellular activity was determined by incubation of PMNs containing intracellular blastospores in the presence of voriconazole for 3 h. RESULTS: The uptake of voriconazole by PMNs was rapid and not saturable. The cellular to extracellular concentration (C/E) ratio for voriconazole was 8.5+/-1.3. Voriconazole was rapidly released from loaded PMNs. The uptake of voriconazole was not affected by environmental temperature and cell viability. Neither the external pH nor the metabolic inhibitors affected the uptake of voriconazole. The ingestion of opsonized zymosan, but not of opsonized Candida spp., significantly decreased the levels of PMN-associated voriconazole. At the extracellular concentrations evaluated, voriconazole did not affect the intracellular survival of Candida. CONCLUSIONS: Voriconazole reached high intracellular concentrations within human PMNs. The uptake was rapid and not saturable but it did not affect the intracellular killing of Candida spp.

La microbiología oral en la era de la genómica y la proteómica / Oral microbiology in the era of genomics and proteomics

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Oral flora in the age of molecular biology.

The present work describes the fundamental aspects of the molecular methods that are applied to oral microbiology: probes, PCR, multiple real time PCR, 16S rDNA, and proteomics. Likewise, it presents the results obtained by applying these methods to the study of the bacterial flora encountered inside the mouth. By identifying 16S rDNA, up to 132 known species and 215 new, unknown phylotypes have been detected inside patients s periodontal pockets. We are currently using a commercial system based on multiple PCR (genomic amplification), followed by reverse hybridization to detect the five species known to cause periodontal disease. We also summarize the findings derived from the application of proteomic techniques to the study of odontologic infections pathogenesis and from the use of molecular methods in the study of resistance to antimicrobial agents. Finally, it puts forth the problems that remain unsolved with respect to oral flora and the treatment of odontogenic infections. Traditional culture methods continue to be indispensable, as they make it possible to later work with the cultured microorganisms.

La flora de la boca en la era de la biología molecular / Oral flora in the age of molecular biology

El presente trabajo describe los fundamentos de los Métodos Moleculares que se han aplicado a la Microbiología oral: sondas, PCR, PCR múltiple y en tiempo real, detección de ARNr 16S y proteómica. Asimismo, se expresan los resultados obtenidos de la aplicación de estos métodos al estudio de la flora bacteriana de la cavidad oral. Por medio de la identificación del ARNr 16S se han encontrado hasta 132 especies conocidas y 215 nuevos filotipos desconocidos en las bolsas periodontales de pacientes. Actualmente, utilizamos un sistema comercial que se fundamenta en la PCR múltiple (técnica de ampliación genómica), seguido de hibridación reversa para detectar las cinco especies reconocidas como periodontopatógenas. También se resumen los hallazgos encontrados con la aplicación de técnicas de proteómica al estudio de la patogénesis de infecciones odontológicas y la aplicación de los métodos moleculares al estudio de resistencia a los antimicrobianos. Finalmente, se exponen los problemas a resolver en el estudio de la flora oral y en el tratamiento de las infecciones odontógenas. Los métodos tradicionales de cultivo siguen siendo imprescindibles, pues permiten un trabajo posterior con el microorganismo cultivado (AU)

The present work describes the fundamental aspects of the molecular methods that are applied to oral microbiology: probes, PCR, multiple real time PCR, 16S rDNA, and proteomics. Likewise, it presents the results obtained by applying these methods to the study of the bacterial flora encountered inside the mouth. By identifying 16S rDNA, up to 132 known species and 215 new, unknown phylotypes have been detected inside patientsʼ periodontal pockets. We are currently using a commercial system based on multiple PCR (genomic amplification), followed by reverse hybridization to detect the five species known to cause periodontal disease. We also summarize the findings derived from the application of proteomic techniques to the study of odontologic infections pathogenesis and from the use of molecular methods in the study of resistance to antimicrobial agents. Finally, it puts forth the problems that remain unsolved with respect to oral flora and the treatment of odontogenic infections. Traditional culture methods continue to be indispensable, as they make it possible to later work with the cultured microorganisms (AU)

Use of positive blood cultures for direct identification and susceptibility testing with the vitek 2 system.

In order to further decrease the time lapse between initial inoculation of blood culture media and the reporting of results of identification and antimicrobial susceptibility tests for microorganisms causing bacteremia, we performed a prospective study in which specially processed fluid from positive blood culture bottles from Bactec 9240 (Becton Dickinson, Cockeysville, Md.) containing aerobic media were directly inoculated into Vitek 2 system cards (bio-Mérieux, France). Organism identification and susceptibility results were compared with those obtained from cards inoculated with a standardized bacterial suspension obtained following subculture to agar; 100 consecutive positive monomicrobic blood cultures, consisting of 50 gram-negative rods and 50 gram-positive cocci, were included in the study. For gram-negative organisms, 31 of the 50 (62%) showed complete agreement with the standard method for species identification, while none of the 50 gram-positive cocci were correctly identified by the direct method. For gram-negative rods, there were 50% categorical agreements between the direct and standard methods for all drugs tested. The very major error rate was 2.4%, and the major error rate was 0.6%. The overall error rate for gram-negatives was 6.6%. Complete agreement in clinical categories of all antimicrobial agents evaluated was obtained for 19 of 50 (38%) gram-positive cocci evaluated; the overall error rate was 8.4%, with 2.8% minor errors, 2.4% major errors, and 3.2% very major errors. These findings suggest that the Vitek 2 cards inoculated directly from positive Bactec 9240 bottles do not provide acceptable bacterial identification or susceptibility testing in comparison with corresponding cards tested by a standard method.

Epidemiology and clinical features of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in nonhospitalized patients.

Infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBLEC) in nonhospitalized patients seem to be emerging in different countries. Their incidence, epidemiology, and clinical impact in the community have not been studied. We describe the epidemiology and clinical features of infections caused by ESBLEC in nonhospitalized patients in Spain and the results of a case-control study performed to investigate the risk factors associated with the acquisition of these organisms. The clonal relatedness of the organisms was assessed by repetitive extragenic palindromic sequence PCR. The ESBLs and the genes encoding the ESBLs were initially characterized by isoelectric focusing and PCR, respectively. Forty-nine patients (76% with urinary tract infections, 22% with asymptomatic bacteriuria, and 2% with acute cholangitis) were included. Six patients were bacteremic. Diabetes mellitus (odds ratio, 5.5; 95% confidence interval, 1.6 to 18.7), previous fluoroquinolone use (odds ratio, 7.6; 95% confidence interval, 1.9 to 30.1), recurrent urinary tract infections (odds ratio, 4.5; 95% confidence interval, 1.3 to 15.1), a previous hospital admission (odds ratio, 18.2; 95% confidence interval, 5.3 to 61.1), and older age in male patients (odds ratio per year, 1.03; 95% confidence interval, 1.03 to 1.05) were identified as risk factors by multivariate analysis. The ESBLEC isolates were not clonally related. The ESBLs were characterized as members of the CTX-M-9 group, the SHV group, and the TEM group in 64, 18, and 18% of the isolates, respectively. ESBLEC is an emergent cause of urinary tract infections in nonhospitalized patients. There was no evidence of horizontal transmission of ESBLEC strains. Avoidance of fluoroquinolone use in high-risk patients should be considered whenever possible in order to avoid the selection of these organisms.

[Comparative in vitro activity of garenoxacin (BMS-284756). Sentry program, Spain (1999-2000)]. / Actividad in vitro comparativa de garenoxacino (BMS-284756). Programa SENTRY España (1999-2000).

INTRODUCTION: To evaluate the in vitro activity of the new des-fluoro quinolone, garenoxacin (BMS-284756), compared to activities of ciprofloxacin, levofloxacin, and gatifloxacin in clinical isolates recovered over 1999 and 2000 within the SENTRY antimicrobial surveillance program. METHODS: Quinolone-MICs were performed using the standard NCCLS microdilution technique in 2599 isolates recovered from Hospital Ramón y Cajal (Madrid), Virgen Macarena (Sevilla), and Bellvitge (Barcelona). RESULTS: The modal MIC range value exhibited by garenoxacin ( < or = 0.03-0.12 mg/L) for Enterobacteriaceae was similar to that of the other quinolones tested. A total of 70% of Pseudomonas aeruginosa isolates were susceptible to garenoxacin and 85% to ciprofloxacin and levofloxacin. Garenoxacin exhibited the highest activity in Staphylococcus aureus, including both methicillin-susceptible and -resistant isolates, with MIC90 values of < or = 0.03 and 2 mg/L, respectively. All Streptococcus pneumoniae isolates were susceptible to garenoxacin, regardless of their penicillin susceptibility status; in terms of MIC90, garenoxacin was 16 times more active than ciprofloxacin and levofloxacin and 4-8 times more active than gatifloxacin. All 6 ciprofloxacin-resistant S. pneumoniae strains showed garenoxacin MIC values ranging from < or = 0.03 to 0.5 mg/L. In Haemophilus influenzae and Moraxella catarrhalis, garenoxacin displayed excellent in vitro activity (MIC < or = 0.06 mg/L), similar to that of the other quinolones tested. CONCLUSIONS: Garenoxacin activity was similar to the activity of other quinolones in Enterobacteriaceae, but was lower in P. aeruginosa. Garenoxacin activity was clearly higher than that of other quinolones in gram-positive isolates, including methicillin-resistant S. aureus and S. pneumoniae with reduced penicillin susceptibility.