Cell Death after Photodynamic Therapy Treatment in Unicellular Protozoan Parasite <em>Tritrichomonas foetus</em>

Programmed cell death in T. foetus does not seem to make sense at first sight; however, different mechanisms of cellular death in this unicellular organism have been observed. This review summarizes the available data related to programmed cell death already published for the cattle parasite T. foetus and attempts to clarify some crucial points to understand this mechanism found in non-mitochondriates parasites, as well as assist in future research. Important results with different treatments showed that the T. foetus can choose among different pathways how to initiate cell death. Thus, a major challenge for cellular death research remains the identification of the molecular cell death machinery of this protist, such as caspases pathway, nuclear abnormalities, morphology cell changes, cellular death in this parasite and the prospects in the future research. Although, the possibility of the existence of different pathways to cell death in trichomonads is discussed and a model for possible executioners pathways during T. foetus cell death is proposed

Isolamento de RNA total de alta qualidade a partir de frutos de melão (Cucumis melo L.) contendo altos níveis de polissacarídeos

Melon, a member of the family Cucurbitaceae, is the fourth most important fruit in the world market and, on a volume basis, is Brazil’s main fresh fruit export. Many molecular techniques used to understand the maturation of these fruits require high concentrations of highly purified RNA. However, melons are rich in polyphenolic compounds and polysaccharides, which interfere with RNA extraction. This study aimed to determine the most appropriate method for total RNA extraction from melon fruits. Six extraction buffers were tested: T1) guanidine thiocyanate/phenol/chloroform; T2) sodium azide/?-mercaptoethanol; T3) phenol/guanidine thiocyanate; T4) CTAB/PVP/?-mercaptoethanol; T5) SDS/sodium perchlorate/PVP/?-mercaptoethanol, and T6) sarkosyl/PVP/guanidine thiocyanate, using the AxyPrepTM Multisource Total RNA Miniprep Kit. The best method for extracting RNA from both mature and green fruit was based on the SDS/PVP/?-mercaptoethanol buffer, because it rapidly generated a high quality and quantity of material. In general, higher amounts of RNA were obtained from green than mature fruits, probably due to the lower concentration of polysaccharides and water. The purified material can be used as a template in molecular techniques, such as microarrays, RT-PCR, and in the construction of cDNA and RNA-seq data.O melão pertencente à família Cucurbitaceae é o quarto fruto mais importante no mercado mundial e a fruta mais exportada pelo Brasil. Muitas técnicas moleculares utilizadas para compreender a maturação destes frutos requerem o uso de RNA altamente purificado e em alta concentração. Entretanto, o elevado nível de compostos polifenólicos e polissacarídeos nos frutos tornam a extração de RNA um desafio. Este trabalho teve por objetivo determinar o método mais adequado para extração de RNA total em frutos de melão. Seis diferentes tampões de extração foram testados: T1) tiocianato de guanidina/fenol/clorofórmio; T2) azida de sódio/?-mercaptoetanol; T3) fenol/tiocianato de guanidina, T4) CTAB/PVP/?-mercaptoetanol, T5) SDS/perclorato de sódio/PVP/?-mercaptoetanol e T6) sarcosil/PVP/tiocianato de guanidina associado com AxyPrep TM Multisource Total RNA Miniprep Kit. O melhor método para extração do RNA tanto de fruto verde quanto maduro foi o baseado no tampão SDS/PVP/?-mercaptoetanol, por gerar material íntegro e de qualidade em grande quantidade, associado à rapidez de execução. Em geral, maiores quantidades de RNA foram obtidas a partir de frutos verdes, provavelmente devido à baixa concentração de polissacarídeos e água. O material purificado poderá ser utilizado como molde em técnicas de estudos moleculares como microarrays, RT-PCR e bibliotecas de cDNA e RNAseq, pelo qual foi testado

Multiple gene sequence analysis using genes of the bacterial DNA repair pathway

The ability to recognize and repair abnormal DNA structures is common to all forms of life. Physiological studies and genomic sequencing of a variety of bacterial species have identified an incredible diversity of DNA repair pathways. Despite the amount of available genes in public database, the usual method to place genomes in a taxonomic context is based mainly on the 16S rRNA or housekeeping genes. Thus, the relationships among genomes remain poorly understood. In this work, an approach of multiple gene sequence analysis based on genes of DNA repair pathway was used to compare bacterial genomes. Housekeeping and DNA repair genes were searched in 872 completely sequenced bacterial genomes. Seven DNA repair and housekeeping genes from distinct metabolic pathways were selected, aligned, edited and concatenated head-to-tail to form a super-gene. Results showed that the multiple gene sequence analysis using DNA repair genes had better resolution at class level than the housekeeping genes. As housekeeping genes, the DNA repair genes were advantageous to separate bacterial groups at low taxonomic levels and also sensitive to genes derived from horizontal transfer

Ardra profiles of bacteria and archaea in mangrove sediments with different levels of contamination in the estuarine complex of Paranaguá, Brazil

The mangrove's sediments from the coastal areas under human activities may contain significant contaminations by hydrocarbons, even when there are no visual evidences of it. The microorganisms are essential to these ecosystems, especially in the control of their chemical environment. Sediment samples were collected in two regions under different environment conditions (pristine and contaminated) of the Paranaguá Estuarine Complex (Paranaguá Bay and Laranjeiras Bay), Brazil. Aliphatic hydrocarbons were determined by the GC-FID to assess the status of contamination of the studied areas. The total DNA was extracted from these samples. The 16S rRNA gene was amplified by the PCR reactions with the pair of primers 21F and 958R for the archaeal domain, and 27F and 1492R for the bacterial domain. Comparisons of communities were made by the ARDRA technique, using the HinfI restriction enzyme. The phosphate concentration showed significant differences between the two regions. The aliphatic hydrocarbons analysis showed the presence of unresolved complex mixture (UCM), an indicator of oil contamination, in the samples from the Paranaguá Bay, which was corroborated by the concentration of total aliphatic hydrocarbons. The ARDRA profile indicated that the structure of archaeal and bacterial communities of the sampled areas was very similar. Therefore, the anthropogenic influences in the Paranaguá Bay showed to be not sufficient to produce disturbances in the prokaryotic dominant groups

Quinolone resistance and ornithine decarboxylation activity in lactose-negative Escherichia coli

Quinolones and fluoroquinolones are widely used to treat uropathogenic Escherichia coli infections. Bacterial resistance to these antimicrobials primarily involves mutations in gyrA and parC genes. To date, no studies have examined the potential relationship between biochemical characteristics and quinolone resistance in uropathogenic E. coli strains. The present work analyzed the quinolone sensitivity and biochemical activities of fifty-eight lactose-negative uropathogenic E. coli strains. A high percentage of the isolates (48.3%) was found to be resistant to at least one of the tested quinolones, and DNA sequencing revealed quinolone resistant determining region gyrA and parC mutations in the multi-resistant isolates. Statistical analyses suggested that the lack of ornithine decarboxylase (ODC) activity is correlated with quinolone resistance. Despite the low number of isolates examined, this is the first study correlating these characteristics in lactose-negative E. coli isolates

Invasion ecology applied to inoculation of plant growth promoting bacteria through a novel SIMPER-PCA approach

da Schoren Costa P, Bolzan de Campos S, Albersmeier A, et al. Invasion ecology applied to inoculation of plant growth promoting bacteria through a novel SIMPER-PCA approach. Plant and Soil. 2018;422(1-2):467-478