Pathological evaluation for sterilization of routinely used prosthodontic and endodontic instruments.

BACKGROUND: In daily practice of dentistry, we use same instruments on many patients. Before use, all instruments must be cleaned, disinfected, and sterilized to prevent any contamination. Pre-cleaning and sterilization of some devices can be difficult because of their small size and complex architecture. Dental burs and endodontic files are such instruments. Dental burs come in a variety of shapes and sizes, all with highly complex and detailed surface features. AIM: To determine the effectiveness of various disinfectants and sterilization techniques for disinfection and resterilization of dental burs and endodontic files. MATERIALS AND METHODS: The materials used for the study were dental burs and endodontic files. Disinfectants used were Quitanet plus, glutaraldehyde, glass-bead sterilizer, and autoclave. The sterility of used dental burs and endodontic files was analyzed. Burs and files that had been used were pre-cleaned, resterilized, and then tested for various pathogens. Each item was transferred by sterile technique into Todd-Hewitt broth, incubated at 37°C for 72 h, and observed for bacterial growth. RESULTS: The present study shows that the endodontic files and burs sterilized by autoclaving and glutaraldehyde showed complete sterilization. Burs and files immersed in glutaraldehyde (2.4%) for 12 h showed complete sterilization, whereas Quitanet plus solution and glass-bead sterilizer showed incomplete sterilization. CONCLUSION: The present study results indicate that autoclaving and glutaraldehyde (2.4%) showed complete sterilization. Other methods cannot be relied upon for sterilization.

Combination of selective enrichment and MALDI-TOF MS for rapid detection of Streptococcus agalactiae colonisation of pregnant women.

Sample preparation was optimized for MALDI-TOF MS directly from selective enrichment broth to detect Streptococcus agalactiae. The method was tested on 100 vaginal samples of pregnant women; positive and negative predictive values were 100 and 91%, respectively. If it indicates positivity, colonisation can be reported 18-24h after sample collection.

Group B streptococcal colonization in 160 mother-baby pairs: a prospective cohort study.

OBJECTIVES: To identify the source of postnatal colonization with group B Streptococcus (GBS) and to evaluate the impact of intrapartum antibiotic prophylaxis (IAP) administration in newborn infant transmission. STUDY DESIGN: A prospective, longitudinal study evaluated GBS colonization in 160 mother-baby pairs. Specimens were collected from the time of delivery to 8 weeks post-partum, from rectum, vagina, and milk of mothers, and from throat and rectum of neonates. Women were grouped according to their GBS status at discharge from the hospital: culture-positive carriers (n = 83), culture-negative carriers (n = 26), and noncarriers (n = 51). Newborns were considered colonized if GBS was yielded from at least 1 site. RESULTS: A total of 35 (21.9%) neonates were colonized; 30 were born to culture-positive carriers, 2 to culture-negative carriers, and 3 to noncarriers. Infants of culture-positive carriers exposed to IAP were less likely to be colonized (15/57 vs 15/26, P = .01), or heavily colonized, (7/57 vs 9/26, P = .04). Of all newborns, those exposed to IAP and discharged GBS-free from hospital, often became colonized subsequently (12/57 vs 1/26, P = .09). Molecular typing analysis (available for 30 of 32 carrier mothers and their infants) confirmed an identical strain of GBS in all mother-baby pairs. Six of 83 culture-positive carrier mothers had a positive milk culture. Their respective neonates all were heavily colonized. CONCLUSIONS: Newborns exposed to IAP and GBS-free at hospital discharge subsequently acquire GBS from their mothers. Culture-positive milk is associated with heavy neonatal colonization.

Comparación de métodos para la recuperación y determinación de la prevalencia de Streptococcus agalactiae en mujeres gestantes de Medellín / Method comparison for the recovery from Streptococcus agalactiae and its prevalence determination in pregnant women of Medellín

Objetivo: Comparar la sensibilidad de losmétodos para la recuperación y la determinación de la prevalencia de S. agalactiae en un grupo de mujeres gestantes de Medellín. Materiales y métodos: Se llevó a cabo un estudio descriptivo de corte. La poblaciónestudiada fueron 362 mujeres gestantes que consultaron en el periodo comprendido entre febrero y octubre de 2008, a las que se les tomaron muestras con hisopo del introitovaginal y de la región anal. Las muestras se cultivaron simultáneamente en agar NuevaGranada y caldo Todd Hewitt con suplemento de antibióticos, a partir del cual se hizo un subcultivo en agar sangre de carnero al 5%. Resultados: Al comparar el método de recuperación en agar Nueva Granada con el método de referencia en caldo Todd Hewitt, la sensibilidad del primero fue de 44% y elvalor diagnóstico positivo de 58%; presentó una alta especificidad (98%) y un valor diagnóstico negativo de 99%. Se identificó S. agalactiae en 21 (5,8%) gestantes. Conclusión: El cultivo en caldo Todd Hewitt es un método sensible para la recuperación deS. agalactiae. Por consiguiente, se recomienda continuar con esta metodología para la tamización de mujeres gestantes en nuestro medio. La prevalencia de 5,8% encontrada eneste estudio concuerda con los reportes de la literatura mundial y, teniendo en cuenta que la tasa de transmisión vertical es, aproximadamente, de 50% (1), se demuestra la necesidad de implementar medidas de vigilancia epidemiológica en nuestro medio.

Objective: Compare method sensitivityfor recovery from S. agalactiae and to determine its prevalence in a group of pregnant women of the city of Medellín.Materials and methods: Cross-sectionaldescriptive study. The population waspregnant women of Medellín who consulted from February to October, 2008; 362 pregnant women were included; the samples were taken from vagina introitus and anal area. The samples were simultaneously cultured in New Granada Agar and Todd Hewitt Broth supplemented with antibiotics, which was the base for the performance of a subculture in Ram Blood Agar at 5%.Results: When comparing the New Granada Agar method of recovery with the Todd Hewitt Broth gold test, the sensitivity of the first was 44% and the positive predictive value was 58%; it presented 98% specificity and a negative predictive value of 99%. S. agalactiae was found in 21 (5.8%)pregnant women. Conclusions: Todd Hewitt Broth is a sensitive method for the recovery from S. agalactiae; therefore, continuing with this methodology for the screening of pregnant women in ourenvironment is recommended. The 5,8% prevalence found in this study is consistent with the reports in world-wide literature. Considering that the rate of vertical transmission isapproximately 50%, the need to implement epidemiological surveillance measures in our environment is evident.

Comparación de medios de cultivos y procedimientos para detectar colonización por Streptococcus agalactiae en mujeres embarazadas / Comparison between culture media and procedures to detect Streptococcus agalactiae in pregnant women

Introducción: La detección de Streptococcus agalactiae en la vagina y/o el recto de las mujeres embarazadas y la administración de profilaxis antimicrobiana intraparto en las colonizadas, es el método recomendado para prevenir la infección neonatal precoz por este patógeno. En consecuencia, es importante seleccionar los medios de cultivos y el sitio de toma de muestra más adecuado para la detección de S. agalactiae en mujeres colonizadas. Objetivo: Comparar diferentes medios de cultivos y procedimientos para la recuperación de S. agalactiae en mujeres embarazadas con complicaciones gineco-obstétricas. Metodología: Se tomaron hisopados vagino-ano-rectales y endocer-vicales de 60 mujeres embarazadas. Con la primera muestra se realizó cultivo directo en agar sangre Columbia selectivo (ASCSD), y caldo selectivo Todd Hewitt (CSTH) incubados a 37 °C, y subcultivos a las 4 y 18 horas en agar sangre Columbia selectivo (ASCS). La segunda muestra se cultivó en ASCS. El ASCSD y ASCS se incubaron en atmósfera microaeróñla a 37 °C durante 24 a 48 horas. La identificación de S. agalactiae se realizó mediante pruebas convencionales. Resultados: Utilizando hisopado vagino-ano-rectal se detectaron 21 pacientes colonizadas con S. agalactiae, de la siguiente manera: 19(31,7 por ciento) en el ASCSD, 21 (35 por ciento) en el CSTH a las 4 horas y 20 (33,3 por ciento) a las 18 horas. De las 21 pacientes colonizadas sólo a una paciente se le detectó S. agalactiae en la muestra de secreción vagino-ano-rectal y endocervical simultáneamente. Conclusión: Los tres procedimientos ensayados presentaron igual efectividad para la recuperación de S. agalactiae; sin embargo, con el uso del ASCSD, se disminuyen los costos y el tiempo de identificación de dicho microorganismo. Por otra parte, el hisopado vagino-ano-rectal resultó ser la muestra más idónea para detectar colonización por S. agalactiae en mujeres embarazadas.

Detection of Streptococcus agalactiae in pregnant women's vagina and rectum and intrapartum antibiotic prophylaxis administered to colonized women are currently recommended to prevent neonatal precocious infections by this organism. In turn, it is very important to select the culture media and adequate sample collection site for S. agalactiae detection in colonized women. To standardize this methods in laboratory, different culture media and procedures for S. agalactiae recovery in pregnant women with obstetric and gynecologic complications were compared. Vaginorectal and endocervical swab specimens were collected from 60 pregnant women. The first sample was placed onto selective Columbia blood agar directly and onto selective Todd-Hewitt broth incubated at 37 °C and subcultured onto selective Columbia blood agar at 4 and 18 hours. The second sample was cultured on selective Columbia blood agar. Both culture media were incubated in a microaerophilic atmosphere at 37 °C from 24 to 48 hours. S. agalactiae was identified using conventional tests. 21 patients colonized with S. agalactiae were detected using vaginoanorectal samples. 19 (31.7 percent) patients tested positive for S. agalactiae through the culture of specimens directly onto selective Columbia blood agar; 21 (35 percent) and 20 (33 percent) patients were found to be positive for S. agalactiae by the selective Todd-Hewitt broth at 4 and 18 hours, respectively. Only one patient tested positive for S. agalactiae in the endocervical tract. The results show that the three procedures followed for S. agalactiae recovery are effective. Nevertheless, the procedure in which the sample was placed directly onto selective Columbia blood agar permits reducing costs and the time for bacteria identification. On the other hand, the vaginoanorectal swab was the best sample to detect colonization by S. agalactiae in pregnant women.