Symbiotic homeostasis of Staphylococcus epidermidis is associated with common skin disorders / 中华皮肤科杂志

Staphylococcus epidermidis can exhibit both protective and opportunistic pathogenic effects on the skin: on the one hand, it suppresses pathogenic bacteria and inflammation, assists the innate immune system of the skin, and maintains homeostasis of skin microenvironment; on the other hand, it exhibits pathogenic potential. How Staphylococcus epidermidis affects human skin conditions depends not only on itself, but also on the communication among it, the host immune system, other microorganisms and environment factors. The balance of this interaction is the symbiotic homeostasis of Staphylococcus epidermidis, and when the homeostasis is disrupted, a variety of skin diseases such as acne vulgaris, atopic dermatitis, rosacea and melanoma can occur. Factors affecting the symbiotic homeostasis of Staphylococcus epidermidis include environmental conditions such as temperature, oxygen content and nutrition, antibiotics, the number of other microorganisms, microecological diversity, etc. This review summarizes recent research progress in symbiotic homeostasis of Staphylococcus epidermidis.

A simple and accurate method for specific quantification of biomass in mixed cultures of filamentous fungi by quantitative PCR / Un método simple y preciso para la cuantificación específica de biomasa en cultivos mixtos de hongos filamentosos por PCR cuantitativa

Abstract Production of lignocellulolytic enzymes by filamentous fungi have a great potential at industrial level due to their widespread applications. Mixed fungal cultures and particularly mixed fungal biofilms constitute a promising fermentation system for an enhanced enzyme production. However, it has not been addressed how much of this enhancement depends on the mixed biomass proportion. In this sense, the aim of this study was to develop a method to specifically and accurately quantify mixed fungal biomass. For this purpose, mixed biofilm cultures composed of Aspergillus niger and Trichoderma reesei, two filamentous fungi used industrially for cellulase production, were collected from 48 to 120 h of growth; mycelia were pulverized, and DNA was extracted for qPCR assays with specific primers for each fungus. Primers were designed from non-conserved regions of sequences of actin and β-tubulin genes of both A. niger and T. reesei. Specificity of these primers was tested in silico and experimentally. A statistically significant correlation was obtained between qPCR-calculated biomass and dry weight biomass data. By this method, it was possible to detect changes on mycelia proportions in biofilms over time, suggesting a competitive interaction between these two fungi. In conclusion, this method allows a specific and accurate quantification of mixed fungal biomass and could be also applied to different mixed culture systems for studying microbial interactions.

Resumen La producción de enzimas lignocelulolíticas por hongos filamentosos tiene un gran potencial a nivel industrial debido a sus diversas aplicaciones. Los cultivos fúngicos mixtos y particularmente las biopelículas fúngicas mixtas constituyen un sistema de fermentación prometedor para una mayor producción enzimática. Sin embargo, no se ha abordado cuánto de esta mejora depende de la proporción de biomasa mixta. En este sentido, el objetivo de este estudio fue desarrollar un método para cuantificar de forma específica y precisa la biomasa fúngica mixta. Para este propósito, se recolectaron cultivos mixtos de biopelículas de 48 a 120 h de crecimiento compuestos por Aspergillus niger y Trichoderma reesei, dos hongos filamentosos utilizados industrialmente para la producción de celulasas; el micelio se pulverizó y el ADN se extrajo para ensayos de qPCR con cebadores específicos para cada hongo. Los cebadores se diseñaron a partir de regiones no conservadas de las secuencias de los genes de actina y β-tubulina de A. niger y T. reesei. La especificidad de estos cebadores se probó in silico y experimentalmente. Se obtuvo una correlación estadísticamente significativa entre la biomasa calculada mediante qPCR y los datos de biomasa en peso seco. Mediante este método, fue posible detectar cambios en las proporciones de los micelios en las biopelículas a lo largo del tiempo, lo que sugiere una interacción competitiva entre estos dos hongos. En conclusión, este método permite una cuantificación específica y precisa de la biomasa fúngica mixta y también podría aplicarse a diferentes sistemas de cultivo mixto para estudiar interacciones microbianas.

Microbial Contamination of Reusable Suction Container and Cost Analysis of Reusable Suction Container and Disposable Suction Container

PURPOSE: The purpose of this study was to check the degree of residual microbial contamination after disinfection of reusable suction containers, used in an intensive care unit (ICU) and present basic data for efficient use through cost analysis in comparison to disposable suction containers. METHODS: This study was conducted on 32 reusable suction containers used in an ICU on a selected specific day. After disinfection and washing, specimens were collected from the used containers and cultured to check for microbial contamination. Additionally, a comparative narrative study analyzes the cost of using reusable suction containers and disposable suction containers. Data were analyzed with the SPSS WIN 20.0 program using real numbers and percentage χ²-test. RESULTS: As a result of the study, microorganisms were found in all samples where in 30 were gram-positive (62.5%) while 13 were gram-negative (27.1%). Based on level of contamination, microorganisms were less than 10CFU/ml in 18 samples (56.3%); 11–99CFU/ml in six samples (18.8%); and more than 100CFU/ml in eight samples (25%). Cost per day for a reusable suction container was 10,655 + α while cost per day for a disposable suction container was 10,666 won. CONCLUSION: This study found that reusable suction containers, even after disinfection, accounted for factors of potential infection as well as microbial contamination. So, disposable suction containers are superior in cost-effectiveness and highly efficient for use with infected patients.

Ex vivo model for studying polymicrobial biofilm formation in root canals / Modelo ex vivo para el estudio de la formación de biopelícula polimicrobiana en conductos / Efeitos sobre a pesca nos elasmobrânquios no Pacífico colombiano

Abstract Endodontic disease has mainly a microbial origin. It is caused by biofilms capable of attaching and surviving in the root canal. Therefore, it is important to study the conditions in which those biofilms grow, develop and colonize the root canal system. However, few studies have used natural teeth as models, which would take into account the root canal anatomical complexity and simulate the clinical reality. In this study, we used human premolar root canals to standardize in vitro biofilm optimal formation conditions for microorganisms such as Enterococcus faecalis, Staphylococcus aureus and Candida albicans. 128 lower premolars underwent canal preparation using K-type files, and were treated with 5.25% sodium hypochlorite and EDTA. Samples were inoculated with microorganisms and incubated for 15, 30, 45, and 60 days under anaerobiosis (CO2 atmosphere) and aerobiosis. Microorganism presence was confirmed by Gram staining, cell culture, and electron microscopy. Exopolysaccharide matrix and microorganism aggregation were observed following 15 days of incubation. Bacterial growth towards the apical third of the root canal and biofilm maturation was detected after 30 days. CO2 atmosphere favored microbial growth the most. In vitro biofilm maturation was confirmed after 30 days of incubation under a CO2 atmosphere for both bacteria and yeast.

Resumen La enfermedad endodóntica tiene principalmente un origen microbiano. Es causada por biopelículas capaces de adherirse y sobrevivir en el conducto dental. Por ello es importante estudiar las condiciones en las que estas biopelículas crecen, se desarrollan y colonizan el conducto. Sin embargo, pocos trabajos han utilizado como modelos dientes naturales, que tengan en cuenta la complejidad anatómica de los conductos y simular la realidad clínica. En este estudio se utilizaron conductos de premolares para estandarizar las condiciones óptimas de formación in vitro de la biopelícula de microorganismos como Enterococcus faecalis, Staphylococcus aureus and Candida albicans. Se prepararon los conductos de 128 premolares inferiores usando limas para endodoncia tipo-K, y fueron tratados con 5.25 % hipodorito de sodio y EDTA. Las muestras se inocularon con microrganismos y fueron incubadas por 15, 30, 45 y 60 días en anaerobiosis (atmósfera de CO2) y aerobiosis. La presencia de microorganismos fue confirmada por tinción de Gram, cultivo celular y microscopia electrónica. Se observó una matriz de exopolisacáridos y agregación de microorganismos a los 15 días de incubación. Después de 30 días se detectó crecimiento bacteriano hacia el tercio apical del conducto, así como maduración de la biopelícula. La atmósfera de CO2 fue la que más favoreció el crecimiento microbiano. La maduración in vitro de la biopelícula se confirmó después de 30 días de incubación en atmósfera de CO2 tanto para la bacteria como para el hongo.

Resumo A doença endodôntica tem principalmente uma origem microbiana. É causada por biofilmes capazes de se fixar e sobreviver no canal radicular. Portanto, é importante estudar as condições em que esses biofilmes crescem, se desenvolvem e colonizam o sistema de canais radiculares. No entanto, poucos estudos utilizaram dentes naturais como modelo, os quais consideram a complexa anatomia dos canais radiculares e simulam a realidade clínica. Neste estudo, utilizamos canais radiculares pré- molares para padronizar as condições de formação ótima in vitro de biofilme para microrganismos como Enterococcus faecalis, Staphylococcus aureus e Candida abicans. Foram preparados os canais de 128 pré-molares inferiores usando limas odontológicas tipo K, e foram tratados com hipoclorito de sódio 5,25 % e EDTA. As amostras foram inoculadas com microrganismos e incubadas por 15, 30, 45 e 60 dias em anaerobiose (atmosfera de CO2) e aerobiose. A presença de microrganismos foi confirmada por coloração de Gram, cultura celular e microscopia eletrônica. Observou-se uma matriz de exopolisacáridos e um agregado de microrganismos depois de 15 dias de incubação. Após 30 dias de incubação foram detectados crescimento bacteriano no terço apical do canal radicular e maduração do biofilme. A atmosfera de CO2 foi a que mais favoreceu o crescimento microbiano. A maduração in vitro do biofilme foi confirmada depois de 30 dias de incubação em atmosfera de CO2 tanto para bactérias como para fungos.

Vaginal Candida and Microorganisms Related to Sexual Transmitted Diseases in Women with Symptoms of Vaginitis / 대한임상미생물학회지

BACKGROUND: The female genital tract is equipped to deal with a variety of foreign substances including a wide array of microorganisms. It is important to consider Candida-bacterial interactions in balance between healthy colonization versus vaginitis. The objectives of this study were to evaluate the association between microorganism distribution and vaginitis, and to investigate the possibility of an interaction between vaginal Candida and other microorganisms in female genital tract. METHODS: A total of 516 vaginal secretions were collected between October 2008 and June 2010 from patients with suspected vaginitis. Identification of Candida species and detection of 6 fastidious microorganisms (Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum) were performed using a VITEK 2 system (bioMerieux, Inc., Hazelwood, MO, USA) and multiplex PCR (Seegene, Biotechnology, Inc., Seoul, Korea), respectively. RESULTS: M. genitalium, U. urealyticum, and C. trachomatis were more often detected in association with vaginal candidiasis. A statistically significant association between Candida and M. genitalium was observed (P<0.05). N. gonorrhoeae was detected less often in women with vaginal candidiasis. CONCLUSION: The results of this study suggest the possibility that vaginal Candida may associate with some microorganisms in patients with vaginitis. Further studies will be required to define the Candida-bacterial interactions and its mechanisms.