Atividade antibacteriana de nanopartículas de polipirrol diante de Staphylococcus aureus isolados de amostras de leite de vacas e cabras com mastite / Antibacterial behavior of polypyrrole nanoparticles against Staphylococcus aureus isolated from cows and goats with mastitis

The aim of the present study was to evaluate the antibacterial behavior of polypyrrole nanoparticles (PPy-NPs) in water against biofilm producer or not S. aureus isolated from cows and goats with mastitis. One hundred and thirty-eight isolates of S. aureus were initially evaluated for biofilm formation by spectrophotometry in microplates. In addition, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs in water for planktonic S. aureus were determined. From the bovine samples analyzed, 5 (4.46%) S. aureus isolates showed a strong biofilm production, 17 (15.18%) moderate production, 36 (32.14%) with weak production and 54 (48.21%) did not produce biofilms. Strains from goats (26) showed no biofilm production in 18 (69.23%) strains and weak biofilm production in 8 (30.76%) strains. The MIC and MBC of S. aureus to PPy-NPs were found in the same concentration (125搭/mL) in all strains tested, regardless of biofilm production or not. This finding provides a new insight into the interaction between PPy-NPs and S. aureus, and will offer potential benefits for the control of mastitis.(AU)

Elevada frequência de Aeromonas spp. e genes de virulência em cultivos de tilápia-do-nilo (Oreochromis niloticus) em tanques-rede, na região semiárida de Pernambuco, Brasil / High frequency of Aeromonas spp. and virulence genes in Nile Tilapia farms (Oreochromis niloticus) in semi-arid regions of Pernambuco, Brazil

Objetivou-se avaliar a ocorrência de Aeromonas spp. em peixes e amostras de água na região semiárida de Pernambuco e avaliar a frequência de aerolissina (aerA), enterotoxina citotóxica (act), enterotoxina citotônica (alt) e serina protease (ahp) nesses isolados. Foram analisados 70 peixes vivos e oito mortos com sinais clínicos de aeromoniose e 16 amostras de água. Aeromonas spp. foram identificadas por análises microbiológicas (provas bioquímicas) e molecular, usando-se primers específicos para a região 16S rRNA, e a distribuição dos quatro fatores de virulência (aerA, alt, act e ahp) foi investigada por ensaio de PCR. Cento e cinquenta e cinco (84,7%) isolados foram confirmados como Aeromonas spp. na análise molecular. Os genes de virulência mais frequentes foram act (53,55%) e aerA (51,61%). De acordo com o tipo de amostra, observou-se maior frequência do gene aerA (87,5% P=0,0474) em isolados de peixes mortos e a menor frequência do gene act (47,73% P=0,0002) em peixes vivos. Este estudo demonstrou a presença de aeromoniose no cultivo de tilápias em tanques-rede, nos municípios de Jatobá e Petrolândia, na região semiárida de Pernambuco. A detecção de aerA, act e alt pode ser utilizada na tipagem de virulência de Aeromonas spp.(AU)

The purpose of this study was to evaluate the occurrence of Aeromonas spp. from fishes and tilapia net-cage farm water in semi-arid regions of Pernambuco and to evaluate the frequency of the aerolysin (aerA), cytotoxic enterotoxin (act), cytotonic enterotoxin (alt) and serine protease (ahp) genes in Aeromonas isolates. 70 live and eight dead fish with aeromoniosis clinical signs and 16 water samples were analyzed. Aeromonas spp. isolated were identified by microbiological (biochemical evidence) and molecular analysis using specific primers for 16SrRNA region, while the distribution of four virulence factors, including aerA, alt, act and ahp, was investigated by PCR assay. One hundred fifty-five (84.7%) isolates were confirmed as Aeromonas spp. by molecular analysis. The most frequent virulence genes in isolates were act (53.55%) and aerA (51,61%). According to the kind of sample, the higher frequency of aerA gene (87.5% P= 0.0474) was observed in isolates from dead fish and the lowest frequency of act gene (47.73% P= 0.0002) from live fish. This study found the presence of aeromoniosis on tilapia farming in net-cages on Jatobá and Petrolândia counties in the semiarid Pernambuco region. The detection of aerA, act and alt can be used for virulence typing of Aeromonas spp. isolates.(AU)

Comparative study of DNA extraction methodologies from goat sperm and its effects on polymerase chain reaction analysis.

Successful DNA extraction is indispensable for molecular methods based on polymerase chain reaction (PCR); however, goat sperm DNA extraction is limited. Thus, the aim of this study was to evaluate three methods to extract DNA from goat sperm for use in PCR. Eight goat semen pools were used for DNA extraction by using the DNeasy Blood & Tissue Kit, phenol-chloroform, and Chelex-100 methods. DNA samples were analyzed spectrophotometrically to determine the DNA concentration and purity, visualized on 0.8% agarose gel, and used at different amounts (150, 100, 50, 10, and 1 ng) for PCR with electrophoresis, followed by 1.5% agarose gel electrophoresis. The quantity of DNA extracted with Chelex-100 was higher (P < 0.05) than that obtained with either the DNeasy Blood & Tissue Kit or the phenol-chloroform method, with the phenol-chloroform method yielding a greater quantity (P < 0.05) than the kit. The DNeasy Blood & Tissue Kit produced a higher (P < 0.05) purity product than the Chelex-100 method, and all samples obtained by the three protocols were positive for DNA, as assessed by electrophoresis. All of the different concentrations of DNA produced by these methods were amplified by PCR, although for DNA produced by the phenol-chloroform method, PCR was only possible after complementary purification. In conclusion, the Chelex-100 method is cheap, secure, simple, fast, and effective, and is a potential tool for extracting goat sperm DNA without limitations in PCR.

Evaluation of the cytotoxicity, genotoxicity and apoptotic induction of an aqueous extract of Achyrocline satureioides (Lam.) DC.

Achyrocline satureioides is widely consumed as infusion or aperitif and shows important therapeutic properties. Previously, we reported absence of genotoxicity of cold aqueous extract (CAE) of A. satureioides by Allium test. However, one test cannot predict the genotoxic effects of a substance. Thus, the aim of this work was to investigate cytotoxicity, genotoxicity and apoptotic ability of CAE of A. satureioides. In addition, CAE was chemically characterized. The cytotoxicity was evaluated by Trypan blue and MTT assays. The apoptotic capacity was evaluated by Hoechst staining and DNA fragmentation-analysis. The genotoxicity was studied by comet assay (CA) and micronucleus test. The identification and quantification of flavonoids were performed by HPLC-ESI-MS/MS. The cytotoxicity studies indicated low toxicity of CAE. In addition, CAE did not induce apoptotic effects on human PBMCs. CAE did not show genotoxicity in vitro against Vero cells, at 10-50 µg/mL. CAE did not induce in vivo genotoxic effects, but it showed at high concentrations cytotoxicity by micronucleus assay. CAE presented flavonoids such as quercetin, 3-O-methylquercetin and luteolin. In conclusion, A. satureioides at popularly concentrations used, in aperitif or infusion, can be consumed safely because did not show any cytotoxic or genotoxic effects.

Genetic diversity and differentiation of five Cuban cattle breeds using 30 microsatellite loci.

Conservation and improvement strategies in farm animals should be based on a combination of genetic and phenotypic characteristics. Genotype data from 30 microsatellites were used to assess the genetic diversity and relationships among five Cuban cattle breeds (Siboney de Cuba, Criollo Cubano, Cebú Cubano, Mambí de Cuba and Taíno de Cuba). All microsatellite markers were highly polymorphic in all the breeds. The expected heterozygosity ranged from 0.67 ± 0.02 in the Taíno de Cuba breed to 0.75 ± 0.02 in the Mambí de Cuba breed, and the observed heterozygosity ranged from 0.66 ± 0.03 in the Cebú Cubano breed to 0.73 ± 0.02 in the Siboney de Cuba breed. The genetic differentiation between the breeds was significant (p < 0.01) based on the infinitesimal model (F(ST)). The exact test for Hardy-Weinberg equilibrium within breeds showed a significant deviation in each breed (p < 0.0003) for one or more loci. The genetic distance and structure analysis showed that a significant amount of genetic variation is maintained in the local cattle population and that all breeds studied could be considered genetically distinct. The Siboney de Cuba and Mambí de Cuba breeds seem to be the most genetically related among the studied five breeds.

Tracheal stenosis: the long and the short of it.

PURPOSE: The aim of this study was to present slide tracheoplasty as the procedure of choice for tracheal stenosis. From 1990 through 1997, patients referred to University of California, San Francisco for tracheal stenosis were managed by resection and anastomosis. During this period, other centers reported successful use of slide tracheoplasty and, from 1998 to 1999, we performed 3 slide tracheoplasties in addition to 3 more resection and anastomosis procedures. METHODS: Between 1990 and 1999, 9 patients with tracheal stenosis of varying lengths underwent surgery at the University of California, San Francisco. They were treated surgically with either resection and anastomosis or with slide tracheoplasty. RESULTS: Two of the 6 patients treated by resection and anastomosis had an anastomotic breakdown; all 3 patients undergoing slide tracheoplasty did not have anastomotic problems. Technically, a slide tracheoplasty has only one half the tension distributed over an oblique anastomosis that is more than the circumferential length of a resection and anastomosis approach. CONCLUSION: Based on these results, a slide tracheoplasty may be the procedure of choice for tracheal stenosis, whether long or short.