Multispecies biofilm removal by XP-endo Finisher and passive ultrasonic irrigation: A scanning electron microscopy study.

The aim was to assess the effect of XP-endo Finisher (XPF) on multispecies biofilm removal, in comparison with passive ultrasonic irrigation (PUI) and conventional syringe irrigation (CSI), by scanning electron microscope (SEM). Fifty mandibular first premolars were instrumented, longitudinally sectioned. The split halves were incubated for 4 days with a broth obtained from three bacteria strains: Enterococcus faecalis, Eikenella corrodens and Streptococcus anginosus. Subsequently, the re-approximated split halves were irrigated with 4% sodium hypochlorite (NaOCl) or water using CSI, and the final irrigation protocols were CSI with 4% NaOCl (CSI+4%NaOCl), PUI+4%NaOCl, XPF+4%NaOCl and CSI+water. The analysis of biofilm removal was performed using SEM images. There were no differences between PUI and XPF (P > 0.05), and both groups promoted higher biofilm removal than CSI+4%NaOCl and CSI+water groups (P < 0.05). It can be concluded the multispecies biofilm removal was significantly improved using XPF and PUI when compared to CSI.

Bioprospection of native psychrotolerant plant-growth-promoting rhizobacteria from Peruvian Andean Plateau soils associated with Chenopodium quinoa.

The Peruvian Andean Plateau, one of the main production areas of native varieties of Chenopodium quinoa, is exposed to abrupt decreases in environmental temperature, affecting crop production. Plant-growth-promoting rhizobacteria that tolerate low temperatures could be used as organic biofertilizers in this region. We aimed to bioprospect the native psychrotolerant bacteria of the quinoa rhizosphere in this region that show plant-growth-promoting traits. Fifty-one strains belonging to the quinoa rhizosphere were characterised; 73% of the total could grow at low temperatures (4, 6, and 15 °C), whose genetic diversity based on DNA amplification of interspersed repetitive elements (BOX) showed 12 different profiles. According to the 16S rRNA sequence, bacterial species belonging to the classes Beta- and Gammaproteobacteria were identified. Only three (6%) isolates identified as nonpathogenic bacteria exhibited plant-growth-promoting activities, like IAA production, phosphate solubilization, growth in a nitrogen-free medium, and ACC deaminase production at 6 and 15 °C. ILQ215 (Pseudomonas silesiensis) and JUQ307 (Pseudomonas plecoglossicida) strains showed significantly positive plant growth effects in aerial length (about 50%), radicular length (112% and 79%, respectively), and aerial and radicular mass (above 170% and 210%, respectively) of quinoa plants compared with the control without bacteria. These results indicate the potential of both psychrotolerant strains to be used as potential organic biofertilizers for quinoa in this region.

Effectiveness of different disinfection techniques of the root canal in the elimination of a multi-species biofilm.

BACKGROUND: The purpose of the study was to evaluate the effectiveness of different root canal disinfection techniques in the elimination of a multi-species biofilm from inside the root canal. MATERIAL AND METHODS: Fifty mandibular first premolars were used in the present study, standardized to 11mm of root length, and instrumented with a reciprocation system Reciproc, (VDW GmbH, Munich, Germany) to a #50. Longitudinally sectioned halves of the roots were obtained and washed with NaOCl 4%, EDTA 17% and 5% sodium thiosulfate, and sterilized by autoclaving for 15 minutes at 121°C. A multi-species biofilm broth was developed with three strains of bacteria under laboratory conditions: Enterococcus faecalis ATTC 29212, Eikenella corrodens ATTC 23834, Streptococcus anginosus ATTC 33397. Roots were autoclaved and transferred to the broth for 4 days and then were subjected to either disinfection with sodium hypochlorite 4% and XP-endo Finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland) or chlorhexidine 2% with and without activation with XP-endo Finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland). RESULTS: The evaluations of the biofilm elimination showed results that indicate that the 4% sodium hypochlorite group with positive pressure irrigation presented significant differences with the group that had irrigation with sodium hypochlorite activated with XP-endo Finisher and the chlorhexidine groups to 2% (P<0.05). CONCLUSIONS: Chlorhexidine 2% activated with the XP-endo Finisher does not exert elimination or improved cleaning effect on the multi-species biofilm. Activation of sodium hypochlorite 4% improved the elimination of the multi-species biofilm. Key words:Biofilm, multispecies, chlorhexidine, sodium hypochlorite.

Development and validity evidence of the multidimensional scale of sexual self-concept in a Spanish-speaking context.

BACKGROUND/OBJECTIVE: STIs and HIV/AIDS are an important public health problem, transmitted by risky sex behaviours. In this context, it is necessary to identify protective factors, of those behaviours, as sexual self-concept. Sexual self-concept is a multidimensional trait (i.e. sexual self-esteem; sexual self-efficacy; and sexual assertiveness), but, in an extensive review, we did not find any measure to assess this multidimensional construct in a Spanish-speaking context. The objective of this research is development a scale to assess sexual self-concept in young people and adults. METHOD: Time-space sampling with a total size of 792 participants, coming from the two Chilean cities (i.e. Arica and Iquique) with the highest HIV rates, aged between 17 and 53 years old (ME = 23.42; SD = 6.33), with 66.2% women (N = 500), 33.6% men (N = 258). RESULTS: Final scale has 16 items and 4 dimensions: sexual self-esteem, sexual self-efficacy, assertive sexual communication, and assertive sexual behaviour. The identified structure provides satisfactory levels of reliability (ω > .8) and presents robust evidence of validity, based on the internal structure of the test, using ESEM (RMSEA = .060; CFI = .99; TLI = .98), evidence of validity based on relationship to other variables (i.e. risky sexual behaviour) and measurement invariance between men and women. CONCLUSIONS: The multidimensional scale of sexual self-concept has adequate psychometric properties to assess sexual self-concept in equivalent samples.

Development and validity evidence of the multidimensional scale of sexual selfconcept in a Spanish-speaking context

Abstract Background/objective: STIs and HIV/AIDS are an important public health problem, transmitted by risky sex behaviours. In this context, it is necessary to identify protective factors, of those behaviours, as sexual self-concept. Sexual self-concept is a multidimensional trait (i.e. sexual self-esteem; sexual self-efficacy; and sexual assertiveness), but, in an extensive review, we did not find any measure to assess this multidimensional construct in a Spanish-speaking context. The objective of this research is development a scale to assess sexual self-concept in young people and adults. Method: Time-space sampling with a total size of 792 participants, coming from the two Chilean cities (i.e. Arica and Iquique) with the highest HIV rates, aged between 17 and 53 years old (ME = 23.42; SD = 6.33), with 66.2% women (N = 500), 33.6% men (N = 258). Results: Final scale has 16 items and 4 dimensions: sexual self-esteem, sexual self-efficacy, assertive sexual communication, and assertive sexual behaviour. The identified structure provides satisfactory levels of reliability (ω > .8) and presents robust evidence of validity, based on the internal structure of the test, using ESEM (RMSEA = .060; CFI = .99; TLI = .98), evidence of validity based on relationship to other variables (i.e. risky sexual behaviour) and measurement invariance between men and women. Conclusions: The multidimensional scale of sexual self-concept has adequate psychometric properties to assess sexual selfconcept in equivalent samples.

Antimicrobial resistance not related to 1,2,3 integrons and Superintegron in Vibrio spp. isolated from seawater sample of Lima (Peru).

Antimicrobial resistance (AMR) in microorganisms has been attributed to integrons, which have the ability to capture antimicrobial resistance gene cassettes and express them in their hosts. 170 strains of Vibrio spp. were isolated from Lima (Peru) seawater samples and identified by biochemical tests and PCR. AMR profiles were generated using 15 standard antibiotics. The presence of class 1, 2 and 3 integrons and Superintegron in these strains were also investigated by PCR. Ten species of Vibrio were identified with V. alginolyticus the most frequent. All strains were resistant to antibiotics, especially to penicillin group. No resistance to norfloxacin or tetracycline was observed. Class 1, 2 and 3 integrons were not found, only one Superintegron containing the mutT gene was identified in V. cholerae L22 strain. This indicated that AMR is not related to integrons as mentioned previously and that these strains can be reservoirs of resistance genes in marine environments.

[Development of a professional social responsibility questionnaire for physicians]. / Construcción y análisis psicométrico de un cuestionario para evaluar el comportamiento médico socialmente responsable.

BACKGROUND: Professional Social Responsibility is now imperative for the practice of medicine. However, there are no instruments to assess it among physicians. AIM: To construct and evaluate the factorial structure and reliability of a questionnaire designed to measure socially responsible behavior in physicians. MATERIAL AND METHODS: The Questionnaire on Medical Socially Responsible Behavior, consisting of 34 items, was constructed. It was applied to 284 physicians and medical students. After eliminating respondents who omitted questions, a valid sample of 214 individuals aged 23 to 67 years (51.4% males) was obtained. We assessed the factorial structure, reliability, discriminative ability of the items and correlation between factors. RESULTS: Exploratory factorial analysis, conducted using the principal axis method, identified the presence of three factors and considered 30 items. The reliability of the factors, assessed using Cronbach's alpha, ranged from 0.73 to 0.89. Only one item had a low correlation of 0.3. Correlations between the three factors were direct and high. CONCLUSIONS: The developed questionnaire presents a definite factorial structure, with internally consistent and correlated factors and with adequate psychometric properties.

Bartonella bacilliformis, endemic pathogen of the Andean region, is intrinsically resistant to quinolones.

OBJECTIVES: To analyze the sequence of the region involved in the development of quinolone resistance of the gyrA and parC genes in a series of Bartonella bacilliformis isolates recovered prior to the introduction of quinolones, as well as one clinical isolate recovered in the 1970s, establishing the susceptibility levels to nalidixic acid and ciprofloxacin. METHODS: Five B. bacilliformis were studied: four isolated before 1957, prior to the introduction of quinolones in clinical practice. The remaining strain was isolated in 1977. A fragment of the gyrA and parC genes was amplified and sequenced. Susceptibility to nalidixic acid and ciprofloxacin was established by the E-test method. RESULTS: All the strains were resistant to nalidixic acid (minimum inhibitory concentration (MIC) >256 mg/l). Three isolates presented decreased susceptibility to ciprofloxacin and two were highly resistant (MIC >32 mg/l). All the strains presented an Ala at position 91 of GyrA and position 85 of ParC. CONCLUSIONS: B. bacilliformis presents a constitutive resistance to quinolones, which may be related to the presence of Ala at position 91 of GyrA and 85 of ParC. These results advise against the current clinical guidelines recommending the use of ciprofloxacin to treat bartonellosis in some countries of the Andean area.

Evaluación in vitro de la resistencia a ciprofloxacina en biopelículas y poblaciones planctónicas de pseudomonas aeruginosa de origen hospitalario / In vitro determination of ciprofloxacin resistance in Pseudomonas aeruginosa and hospital planktonic populations

Objetivo: Evaluar la susceptibilidad / resistencia in vitro de biopelículas y poblaciones planctónicas de Pseudomonas aeruginosa de origen hospitalario a la ciprofloxacina y compararlas con los resultados con las pruebas de susceptibilidad estándar obtenidos. Diseño: Estudio microbiológico. Lugar: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, UNMSM. Material biológico: Cepas de Pseudomonas aeruginosa. Intervenciones: En cepas resistentes y sensibles obtenidas del Hospital del Niño, se realizó pruebas de concentración mínima inhibitoria (MIC); luego, se procedió a formar las biopelículas, en membranas de filtración y cultivos planctónicos en caldo, para ser sometidos ambos a diferentes concentraciones de ciprofloxacina y realizar el conteo en placas a intervalos de 40 minutos y a las 24 horas de exposición. Principales medidas de resultados: Susceptibilidad / resistencia in vitro de biopelículas y poblaciones planctónicas de Pseudomonas aeruginosa de origen hospitalario. Resultados: Al examinar la cepa sensible, ésta incrementa suresistencia en más de 200 veces, bajo la forma de biopelícula, encontrándose una diferencia poco significativa en las cepas resistentes, ya que la población comienza a disminuir alrededor de una concentración de 128 μg/mL de la droga. Conclusiones: Una misma cepa, como en el caso de la Pseudomona aeruginosa, tiene un comportamiento distinto a la ciprofloxacina, de acuerdo a su forma de crecimiento. Se recomienda la determinación del MIC en biopelículas de agentes etiológicos de infecciones recurrentes y crónicas que desarrollan el estado de biopelícula.

Objective: To assess in vitro sensitivity / resistance of biofilms and planktonic populations of Pseudomonas aeruginosa from a hospital environment to ciprofloxacin and to compare them against the results of standard susceptibility test obtained. Design: Microbiological study. Setting: Molecular Microbiology Laboratory, Faculty of Biological Sciences, UNMSM. Biologic material: Pseudomonas aeruginosa strains. Interventions: Resistant and susceptible strains obtained form Hospital del Niño were tested for minimum inhibitory concentration (MIC); then biofilms were formed on filtration membranes, and planktonic cultures in broth were tested with different ciprofloxacin concentrations, with plate count at 40 minutes intervals and 24 hours after exposure. Main outcome measures: In vitro susceptibility / resistance of hospital origin Pseudomonas aeruginosa biofilms and planktonic populations. Results: Sensitive strains increase their resistance more than 200 times under biofilm growth; no significant difference was found with resistant strains and both start to decrease their population at about 128 ìg/Ml drug concentration. Conclusions: The same strain, as in case of Pseudomona aeruginosa, has a different response to ciprofloxacin, according to its growth. A MIC biofilm test of recurrent and chronic infections etiological agents is recommended.

Estudio preliminar de la resistencia de Vibrio cholerae O1, brote epidémico 1998, a antimicrobianos / Preliminary survey from the antimicrobial resistance of Vibrio cholerae O1, epidemic outbreak 1998

Thirty strains of V. cholerae 01 Ogawa and 2 Inaba, isolated during the outbreak of 1998, were studied in relation to thier sensibility in front of 10 antibiotics of clinical use. Nine strains were determined (28.1 por ciento) resistant to 1 up to 6 antibiotics. The SDS-PAGE of the studied strains exhibited similar pattern of bands.

Vibrios no epidémicos y Vibrio cholerae O1 asociados a enfermedad diarréica aguda. Evento climatológico "El Niño"-1998. Hospital Nacional Dos de Mayo / Non-epidemic vibrios and vibrio cholerae O1 associated with acute diarrhea from cases given during

OBJETIVOS: Aislar e identificar Vibrio cholerae O1 y especies de vibrios no epidémicos asociados a casos de enfermedad diarreica aguda (EDA) durante 1998, dentro del evento climatológico "El Niño" Oscilación del Sur (ENOS). MATERIALES Y MÉTODOS: Durante los meses de verano de 1998 se realizó 70 coprocultivos de pacientes con EDA admitidos en la sala de emergencia del Hospital Nacional Dos de Mayo de Lima. Se estudió colonias aisladas en Agar TCBS. Los aislados fueron sometidos a pruebas bioquímicas y serológicas para la identificación de Vibrio cholerae O1. La identificación de vibrios no epidémicos y otros vibrios patogénicos se realizó tomando en consideración las características descritas en el Manual de Sistemática Bacteriana de Bergey (1994). RESULTADOS: Los resultados indican que el mayor numero de casos estudiados estuvieron asociados a Vibrio cholerae O1 como agente etiológico único (64,3) o relacionados a otras especies de Vibrio (4,2). Se relata 2 casos (2,9) que involucraron a V. vulnificus y 3 (4,3) a V. parahaemolyticus como agentes etiológicos de diarrea aguda. CONCLUSIONES: La asociación de Vibrio cholerae O1 con otras especies de vibrios no epidémicos permitiría establecer una relación directa entre las infecciones diarreicas estudiadas y el ENOS.