ABSTRACT
Introdução: O transplante de córneas é o principal tratamento para pessoas que apresentam distúrbios de curvatura ou transparência da córnea. No Brasil, não há protocolo unificado para meios de preservação, tempo de armazenamento e antibióticos utilizados. A preocupação é a de que patógenos possam ser transferidos aos receptores de transplantes. Objetivo: Realizar o levantamento da microbiota ocular de doadores de córneas a fim de verificar uma possível correlação com infecções em receptores e, dessa forma, auxiliar na melhoria de metodologias e protocolos de armazenamento de córneas. Método: Foi conduzido a partir de revisão da literatura, nas bases de dados PubMed, SciELO e nos portais: periódicos da CAPES, Anvisa, Ministério da Saúde e ABTO, entre 2018 e 2020. Resultados: Estudos baseados em cultivo de microrganismos trazem Staphylococcus coagulase negativa (SCN) de 30% a 100% das amostras isoladas de conjuntivas. Em menor quantidade estão Streptococcus, Corynebacterium e Propionibacterium. Bactérias Gramnegativas aparecem em número inferior, representadas pelos gêneros Haemophilus, Neisseria, Pseudomonas, Enterobacter, Escherichia, Proteus e Acinetobacter. Já as técnicas independentes de cultivo trazem Pseudomonas como a principal colonizadora da conjuntiva. Também apresentam uma diversidade maior de colonizadores, mostrando um potencial campo de estudos, no qual a superfície ocular pode ter uma diversidade muito maior de espécies e potenciais agentes patogênicos. Os principais meios de preservação utilizados no Brasil levam os antimicrobianos gentamicina e estreptomicina em sua composição, porém estudos têm mostrado que as bactérias presentes nos meios de preservação são resistentes a esses antibióticos. Conclusões: Os dados apontam para a necessidade de reavaliação da eficiência desses meios de preservação na descontaminação das córneas para transplante.
Introduction: Corneal transplantation it is the main treatment for people who have corneal curvature or transparency disorders. In Brazil, there is no unifed protocol on the means of preservation, storage time and antibiotics used. The concern is that pathogens are transferred to transplant recipients, causing eye infections after transplantation. Objective: Examine ocular microbiota of corneal donors, to verify a possible correlation with infections in recipients and thus assist in improving corneal storage methodologies and protocols. Method: Literature review conducted in PubMed, SciELO and the following websites: CAPES Journals, Anvisa, Brazilian Ministry of Health and ABTO, between 2018 and 2020. Results: Studies based on microorganism's cultivation show coagulase negative Staphylococcus in 30% to 100% of samples isolated from conjunctiva. In lesser quantities are Streptococcus, Corynebacterium and Propionibacterium. Gram-negative bacteria appear in much lower numbers, represented by the genera Haemophilus, Neisseria, Pseudomonas, Enterobacter, Escherichia, Proteus and Acinetobacter. On the other hand, results based on independent cultivation techniques bring Pseudomonas as the main colonizer of the conjunctiva. Also, they have a much greater diversity of colonizers, showing a potential feld of study. The ocular surface may have a much greater diversity of species and potential pathogens than was expected. The main means of preservation used in Brazil contain the antimicrobials gentamicin and streptomycin in their composition; however, several studies have shown that bacteria present in the means of preservation are resistant to these antibiotics. Conclusions: These data point to the need for a reassessment of the efciency of these means of preservation in decontaminating corneas for transplantation.
ABSTRACT
ABSTRACT The microbial composition of different types,in ecosystems (including agro-ecosystems), has been investigated in a rapidly growing number of studies in the past few years. The importance of microorganisms, regarding the maintenance and stability of nutrients in agroecosystems, is a key to maintain the sustainability of a crop. Molecular tools to study microbial communities are possible through many methods such as RISA, DGGE, TGGE, clone libraries, T-RFLP, RAPD, SSCP and more recently NGS (Next-Generation Sequencing). DGGE is widely employed to characterize the diversity and the community dynamics of microorganisms in the environment, making possible to find out specific groups through functional genes, allowing access to data that cannot be obtained by cultural methods. The aim of this paper is to review the functional groups related to agroecosystems and to indicate the critical choice of DNA primers pairs and targeted DNA regions that may be used in PCR-based methods such as the DGGE technique in order to evaluate the microbial communities in a variety of environments.