Genetic diversity,anti‐microbial resistance,plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil          下载免费PDF全文

F. P. Vilela  M. R. Frazão  D. P. Rodrigues  R. G. Costa  M. R. T. Casas  S. A. Fernandes  J. P. Falcão  F. Campioni 《Zoonoses and public health》2018,65(1):e34-e43

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.  相似文献   

Integrating land cover structure and functioning to predict biodiversity patterns: a hierarchical modelling framework designed for ecosystem management     

Rita Bastos  António T. Monteiro  Diogo Carvalho  Carla Gomes  Paulo Travassos  João P. Honrado  Mário Santos  João Alexandre Cabral 《Landscape Ecology》2016,31(4):701-710

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Landscape context affects site occupancy of pond-breeding anurans across a disturbance gradient in the Brazilian Cerrado     

Luciana Signorelli  Rogério P. Bastos  Paulo De MarcoJr  Kimberly A. With 《Landscape Ecology》2016,31(9):1997-2012

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Genetic characterisation of African swine fever viruses from outbreaks in southern Africa (1973-1999)     

Boshoff CI  Bastos AD  Gerber LJ  Vosloo W 《Veterinary microbiology》2007,121(1-2):45-55

African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in the southern African sub-region, where outbreaks regularly occur. There is anecdotal evidence suggesting that trans-boundary movement of infected animals may have played a role in precipitating widespread outbreaks in the past, however, since the 1970s outbreaks have generally been more localised, particularly in those countries where control of animal movement is strictly regulated. The origin and relatedness of regional ASF outbreaks was investigated here by means of a two-step genetic characterisation approach whereby p72 gene sequencing was used to delineate genotypes, prior to intra-genotypic resolution of viral relationships by central variable region (CVR) characterisation of the 9RL ORF. In this manner, regional virus heterogeneity and epidemiological links between outbreaks could be assessed for the first time through phylogenetic analysis of the C-terminal end of the p72 gene of viruses recovered from domestic pig outbreaks in southern Africa between 1973 and 1999. The phylogeny revealed the presence of 14 distinct p72 genotypes of which 6 (genotypes XVII-XXII) were considered novel. Eight of these were country-specific with the remaining six having a trans-boundary distribution. CVR products were heterogeneous in size ranging from 377bp to 533bp across the 14 southern African genotypes. Within-genotype CVR comparisons revealed the presence of a genotype XIX virus with an extended field presence in South Africa (1985-1996) and permitted discrimination between three genotype VII viruses that were identical across the p72 gene.  相似文献   

Differential pulse polarographic determination of alpha-dicarbonyl compounds in foodstuffs after derivatization with o-phenylenediamine.     

J A Rodrigues  A A Barros  P G Rodrigues 《Journal of agricultural and food chemistry》1999,47(8):3219-3222

A differential pulse polarographic method has been developed for the indirect determination of diacetyl and other vicinal diketones in foodstuffs, based on the quantitative derivatization of the diketones with o-phenylenediamine to give quinoxalines. The method allows the identification of diacetyl and methylglyoxal in brandy, vinegar, wine, and butter samples. The polarographic reduction peaks of the quinoxalines formed are sufficiently separate, in some cases, to allow the simultaneous determination of these two compounds. The polarographic method is not affected by the presence of sulfite ion, probably because the o-phenylenediamine is capable of dislodging the alpha-diketones from their sulfite complexes.  相似文献   

Benefits of using the probiotic Efinol^®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz), in the Amazon     

Levy Carvalho Gomes  Richard Philip Brinn  Jaydione Luiz Marcon  Lucelle Araújo Dantas  Franmir Rodrigues Brandão  Janessa Sampaio de Abreu  Paulo Evandro Mendes Lemos  Dawn Michelle McComb  & Bernardo Baldisserotto 《Aquaculture Research》2009,40(2):157-165

The objective of this experiment was to test the probiotic Efinol^®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz). For the transportation, fish were distributed in 18 plastic tanks, of which nine contained the Efinol^®L (10 mg L⁻¹; probiotic treatment) and the remaining had no probiotic (control treatment). Transport lasted 24 h and three different boxes of each treatment were sampled at 3, 12 and 24 h. Up to the 12-h sampling period, no significant difference in the survival was observed; on the other hand, survival was higher at the end of the transport (24 h) in the probiotic treatment. No significant difference was found in dissolved oxygen and temperature between treatments. Conductivity, pH and alkalinity increased along the transport, but without a difference between treatments. Ammonia increased in all treatments, although it was significantly lower in the probiotic group at 24 h. Cortisol levels were significantly higher in all transported fish when compared with the basal values. At 24 h, cortisol levels in control fish were significantly higher than those in the probiotic treatment. With the observed results, we are able to conclude that the probiotic Efinol^®L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes.  相似文献   

Impact of pond management on tambaqui, Colossoma macropomum (Cuvier), production during growth-out phase     

Levy Carvalho Gomes  & Clichenner Rodrigues Silva 《Aquaculture Research》2009,40(7):825-832

This study evaluated the impact of pond management on tambaqui, Colossoma macropomum (Cuvier), rearing during the growout phase. Juvenile tambaqui were stocked in ponds with three different management regimes: (1) natural ponds (Nat); (2) limed ponds (Lim); and (3) limed and bimonthly fertilized ponds (LimFer). The experiment lasted 210 days and the growth parameters were evaluated monthly. Water quality and effluent measurements were performed every 15 days and at the end of the experiment yield parameters were obtained. There was no difference in weight and length among treatments. Stomach contents and zooplankton availability were not influenced by pond management, but the rearing period had an influence on them. Food conversion rate (FCR) was better in fish from the Lim treatment than in fish from the Nat treatment. The pH, hardness and alkalinity values were significantly higher in the Lim and LimFer ponds, where the liming procedure was performed. The effluent analysis showed a more potentially impacting effluent in the LimFer treatment, where phosphorus and orthophosphate concentrations showed values significantly higher than those in Lim and Nat ponds. The results show that the Lim treatment is the best approach, as in this treatment fish achieve market size, better FCR, yield and have a reduced environmental impact.  相似文献   

Effects of photoperiod on survival and growth of the marine pejerrey Odontesthes argentinensis larvae     

Luciano Siqueira Freitas  Ricardo Vieira Rodrigues  Marcelo Hideo Okamoto  Luiz Roberto Louzada  & Luís André Sampaio 《Aquaculture Research》2009,40(2):252-255

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Liver histology and histomorphometry in hybrid sorubim (Pseudoplatystoma reticulatum × Pseudoplatystoma corruscans) reared on intensive fish farming          下载免费PDF全文

Robson Andrade Rodrigues  Klaus Casaro Saturnino  Carlos Eurico Fernandes 《Aquaculture Research》2017,48(9):5083-5093

This study aimed to characterize the liver histology and histomorphometry in sorubim hybrid of different categories (nursery, growth and grow‐out) reared on fish farming. The categories were defined considering body weight (BW): nursery category (n = 5): BW = 37.06 ± 6.00 g (31.6–45.3 g); growth category (n = 5): BW = 310.40 ± 53.80 g (242.1–376.4 g) and grow‐out category (n = 5): BW = 874.28 ± 27.59 g (846.2–913.1 g). Liver fragments were processed to paraffin inclusion, and sections were stained by haematoxylin and eosin (H&E), PAS (Periodic Acid Schiff) and Perl's staining to histology, histomorphometry and density volumetric of liver structures; glycogen analysis and to detect ferric irons (Fe³⁺) respectively. The hepatosomatic index decreased between the categories (P < 0.01). The percentage of PAS‐positive hepatocytes in the nursery category was higher (P < 0.05) in relation to the growth and grow‐out categories. The hepatocytes from all fish were positive to Perl's staining. The density volumetric of liver structures did not differ among categories except to blood vessels were higher (P < 0.01) in the nursery and growth. The area (μm²) and perimeter (μm) of hepatocytes, and the area (μm²), perimeter (μm) and volume (μm³) of the nuclei from grow‐out fish were lower (P < 0.01) than those from the nursery and growth categories. Changes in morphometric characteristics of hepatocytes may result from metabolic changes associated with body growth surubins; therefore, these morphometric characteristics of liver tissue can be used as functional biomarkers for the assessment of fish health and nutrition status.  相似文献   

Anti-SARS-CoV-2 Activity of Rhamnan Sulfate from Monostroma nitidum     

Yuefan Song  Peng He  Andre L. Rodrigues  Payel Datta  Ritesh Tandon  John T. Bates  Michael A. Bierdeman  Chen Chen  Jonathan Dordick  Fuming Zhang  Robert J. Linhardt 《Marine drugs》2021,19(12)

The COVID-19 pandemic is a major human health concern. The pathogen responsible for COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), invades its host through the interaction of its spike (S) protein with a host cell receptor, angiotensin-converting enzyme 2 (ACE2). In addition to ACE2, heparan sulfate (HS) on the surface of host cells also plays a significant role as a co-receptor. Our previous studies demonstrated that sulfated glycans, such as heparin and fucoidans, show anti-COVID-19 activities. In the current study, rhamnan sulfate (RS), a polysaccharide with a rhamnose backbone from a green seaweed, Monostroma nitidum, was evaluated for binding to the S-protein from SARS-CoV-2 and inhibition of viral infectivity in vitro. The structural characteristics of RS were investigated by determining its monosaccharide composition and performing two-dimensional nuclear magnetic resonance. RS inhibition of the interaction of heparin, a highly sulfated HS, with the SARS-CoV-2 spike protein (from wild type and different mutant variants) was studied using surface plasmon resonance (SPR). In competitive binding studies, the IC₅₀ of RS against the S-protein receptor binding domain (RBD) binding to immobilized heparin was 1.6 ng/mL, which is much lower than the IC₅₀ for heparin (~750 ng/mL). RS showed stronger inhibition than heparin on the S-protein RBD or pseudoviral particles binding to immobilized heparin. Finally, in an in vitro cell-based assay, RS showed strong antiviral activities against wild type SARS-CoV-2 and the delta variant.  相似文献