Maintenance of sterility in SMS packaging in dental environments: concern with biosafety

Healthcare services must be guided by biosafety practices and microbial control. This control is highly influenced by humidity, which directly impacts the maintenance of sterility of the materials used in the appointments. High concentration of moisture, in the form of aerosol, splashes and spills, is caused during dental care. During the COVID-19 times the contamination by aerosol and droplets worries greatly. Considering that it could cause harm to the sterility of an autoclaved material, especially in dental environments, the objective was to evaluate the behavior of SMS sterilization packages (Spunbonded / Meltblown / Spunbonded) against microbial penetration in an aqueous vehicle. SMS of three brands were challenged, equally divided into two groups: virgin and processed (subjected to a single autoclaving cycle). Each specimen was aseptically deposited on Macconkey agar. Subsequently, 5 µL of Escherichia coliATCC 25922 saline solution [108CFU mL-1] was deposited in center of the SMS specimen and the dish incubated at36°C/ 48h. Reading was performed by the presence or absence of bacterial growth typical of the species under the SMS, observed on the back of Petri dish. The lowest penetration rate observed was 60% for one of the brands in the virgin condition, and 75% for two brands in the processed condition. Statistical analysis showed an association between bacterial penetration and the evaluated group, this association being valid only in the virgin condition. The different SMS behave similarly in terms of resistance to bacterial penetration after being processed. The data show that moisture can assist in bacterial transport through sterilized SMS. Therefore, SMS packages are not able to prevent bacterial penetration, and possibly other microorganisms, when in aqueous vehicles, offering a potential risk of breaking the aseptic chain. Thus, care must be taken in routines for handling and storage sterile packaging.

Inmunología perinatal / Perinatal immunology

Se ha considerado que el útero gestante es un lugar inmunológicamente privilegiado, donde el feto es protegido del rechazo por el sistema inmune materno, mediante un amplio repertorio de estrategias de evasión que contribuye a la sobrevivencia del feto. La gestación en sí misma constituye un acontecimiento de equilibrio inmunológico y la tolerancia inmunológica permite la progresión del embarazo, donde participan una secuencia sincronizada de eventos que se inicia desde la concepción y fertilización para dar lugar a la implantación y progresa hasta alcanzar un embarazo a término. El sistema inmune es la principal barrera que poseemos para protegernos de las infecciones. Durante la vida intrauterina, el feto está protegido por la madre de las agresiones externas, por lo que no necesita que su sistema inmunológico sea operativo, sin embargo, al nacer, recibe una avalancha de elementos extraños, por lo que necesitará disponer de cierta protección, así como una preparación para ejecutar las defensas necesarias para su protección inmunológica. La inmunidad sérica durante la vida fetal queda limitada a la transferencia a través de la placenta de IgG materna, a pesar de que el feto tiene la facultad de sintetizar inmunoglobulinas desde las primeras etapas de la gestación. Al nacimiento, el niño tiene su sistema inmunológico completo, aunque inmaduro, pero es capaz de responder a los estímulos antigénicos. Tiene múltiples anormalidades en el desarrollo de su sistema inmune, que involucran a los anticuerpos/inmunoglobulinas, complemento y granulocitos pudiendo contribuir a la alta incidencia de sus infecciones. El recién nacido carece de memoria inmunológica debido a que, en condiciones normales, el feto está exento de estímulos producidos por antígenos extraños. Dicha memoria se va adquiriendo a medida que entra en contacto con los diferentes antígenos. Se obtendrá cierta protección a las infecciones entéricas gracias a las IgA que aporta la lactancia materna. La exposición prenatal y postnatal a productos microbianos ambientales que pueden activar la inmunidad innata, puede acelerar el proceso de maduración del sistema inmune.(AU)

It has been considered the pregnant women`s womb as an immunological exceptional place, where fetus is protected against been rejected because of maternal immune system by means of a wide groups of evasive strategies that help in its survival. Pregnancy itself is an immunological equilibrium state and the immunological tolerance allow the progression of this event, where participate a synchronized sequence of biological events started from conception and fertilization to allow the implantation, and progress until to reach the pregnancy end. The immune system is our main barrier against infections. During intrauterine life fetus is protected by the mother against external aggressions, therefore he don`t need an operative immune system, nevertheless, at birth the new organisms receive an avalanche of strange elements needing some kind of protection as well as a preparation to carry out the necessary defense for his immunological protection. Serum immunity during fetal life is limited to the transference of maternal IgG through placenta, despite fetus capability to synthesize immunoglobulins from first stages of gestation. At birth the babe has a complete immunological system although immature but capable to respond to antigenic stimulus. He has multiples abnormalities in the immune system development that take account antibodies/immunoglobulin, complement and granulocytes contributing to his high incidence of infections. Newborn lack immunological memory because in normal conditions fetus is not stimulated by odd antigens. This memory is acquired through the contact with different antigens. It will be obtained some protection against enteric infections because IgA from maternal lactation. The prenatal and postnatal exposition to environmental microbial products that activate the innate immunity can accelerate the immune system maturing process.(AU)

Espectro de patógenos pulmonares en pacientes VIH+ en la era TARGA / Spectrum of pulmonary pathogens in HIV + patients in the HAART era

La infección por el Virus de Inmunodeficiencia Humana es un importante problema de salud pública a pesar del advenimiento de la terapia antiretroviral. Describir los patógenos pulmonares más frecuentes en pacientes VIH+ en la era del uso de terapia antirretroviral de gran actividad (TARGA). Se evaluaron 35 pacientes VIH+ que acudieron al Servicio de Neumonología y Cirugía de Tórax del Instituto Autónomo Hospital Universitario de Los Andes (Mérida, Venezuela). Se realizó evaluación clínica y fibrobroncoscopia con la finalidad de obtener muestras para cultivos cuantitativos bacteriológicos, micológicos y estudio anatomopatológico. Todos los pacientes mostraron síntomas respiratorios; sólo la disnea fue más frecuente en pacientes sin TARGA. Las alteraciones radiológicas no fueron significativamente diferentes entre ambos grupos de pacientes; sin embargo, el engrosamiento septal evidenciado en la TCAR (tomografía de alta resolución) de Tórax y la neumonía intersticial en las muestras histopatológicas fueron más frecuentes en pacientes que no recibían TARGA. El 72% de los pacientes tuvo cultivos bacteriológicos positivos, asociados con niveles bajos de CD4+ (p=0.02). El 37% mostró cultivos micológicos positivos, pero ningún paciente presentó serología positiva para los hongos cultivados del LBA. El 57% presentó evidencias histopatológicas de infección por P. jirovecci, generalmente asociada a coinfección con C. albicans y/o H. capsulatum. A pesar del uso de terapia antiretroviral, las patologías pulmonares infecciosas siguen siendo causa frecuente de morbilidad en pacientes infectados con el VIH en Venezuela.

HIV infection is an important public health problem despite the use of antiretroviral therapy. To determine the pathogens in a group of HIV+ patients with lung infections in the era of current high activity anti-retroviral therapy (HAART). Thirty five patients who consulted to the Pulmonary and Thoracic Surgery Department of the University Hospital of Los Andes (Mérida, Mérida state, Venezuela) were evaluated. Clinical evaluation and flexible bronchoscopy were done to obtain samples for quantitative bacterial culture, mycological culture and anatomopathologic evaluation. All patients showed respiratory symptoms, but dyspnea was more frequent in patients not receiving HAART. Radiologic findings were not different between the two groups of patients although septal thickening in High Resolution Computed Thoracic Tomography (HRCT) and interstitial pneumonia in histopathologic samples were more often found in patients not receiving HAART. 72% of had positive bacterial cultures and these were associated with low CD4+ count (p = 0.02). 37% of patients showed positive my cological culture, although none of them showed positive serology for any of the fungi cultured from bronchoalveolar lavage. 57% of patients showed histopathologic evidence of P. jirovecci infection, generally associated with confection by C. albicans and/or H. capsulatum. Despite the use of antiretroviral therapy, pulmonary infectious diseases continue to be a major cause of morbidity among HIV infected patients in Venezuela.