Genotoxic parameters of human degenerated intervertebral discs are linked to the pathogenesis of disc degeneration

BACKGROUND

Degenerative disc disease (DDD) is a prevalent disorder that brings great incapacity and morbidity to the world's population. Its pathophysiology is not fully understood. DNA damage can influence this process, but so far, there have been few studies to evaluate this topic and its true importance in DDD, as well as whether there is a relation between degeneration grade and DNA damage. The objective of this study is to evaluate the degree of damage to the DNA and the relation to the severity of DDD and measure its response to this insult compared to live/dead cell parameters and reactive oxygen species activity in human discs.

METHODS

An experimental study was performed with 15 patients with grade IV or V Pfirrmann classification who underwent spinal surgery. Five patients were operated on two levels, resulting in 20 samples that were submitted to the comet assay to measure DNA damage. Of these, six samples were submitted to flow cytometry, and apoptosis, necrosis, cell membrane integrity, intracellular esterase activity, reactive oxygen species (ROS), caspase 3 and mitochondrial membrane potential were evaluated.

RESULTS

All samples had DNA damage, and the average of index damage (ID) was 78.1 (SD ± 65.11) and frequency damage (FD) was 49.3% (SD ± 26,05%). There was no statistical difference between the Pfirrmann grades and genotoxic damage. Likewise, all samples that underwent flow cytometry showed apoptosis and ROS to many different degrees.

CONCLUSIONS

DNA damage occurs in high-grade degeneration of human discs and contributes to activation of the apoptosis pathway and ROS production that can accelerate disc degeneration.

Corrigendum to "The effect of ion-exchange resin treatment on grape must composition and fermentation kinetics" [Heliyon 6, (3), (March), Article e03692]

[This corrects the article DOI: 10.1016/j.heliyon.2020.e03692.].

The effect of ion-exchange resin treatment on grape must composition and fermentation kinetics

The aim of this study was to determine the influence of ion-exchange resin treatments of white grape must for the production of sparkling base wines, on the grape must chemical composition and fermentation kinetics. The experiment included an untreated grape must with a pH of 3.2, and resin-treated musts with pH 3.14, 3.07, and 3.01. Analysis of pH, total acidity, optical density (O.D.) at 420 nm, total phenolic content, tartaric acid, ammonium-nitrogen (AN) and cations (Ca²⁺, Mg²⁺, Cu²⁺, K⁺, and Na⁺) was performed. The fermentations were monitored by mass reduction (CO₂ release g/L), and fermentation parameters obtained from a modified non-linear sigmoidal equation. The analyses of the musts showed differences in the concentration of metals, total acidity, tartaric acid, AN and O.D. 420 nm. The kinetic parameters of the fermentation showed significant changes between the control must and the ion-exchange treatments. This study showed that the treatment with cationic resins at the tested level significantly affects the chemical composition of the musts, interfering with the fermentation kinetics. In addition, reductions in the must pH index close to 0.1 unit can lead to positive results in the characteristics of the base must of sparkling wines.

Alternative control of grape rots by essential oils of two Eucalyptus species

BACKGROUND

Essential oils (EOs) are volatile natural compounds produced by plant secondary metabolism, and some of them exhibit antimicrobial activity. The objective of the present study was to determine the chemical composition the EOs of Eucalyptus staigeriana and Eucalyptus globulus, and their effect in vitro and in vivo against Botrytis cinerea and Colletotrichum acutatum, the most important fungal rot diseases of grapes. Moreover, grapes collected from field experiments were used to evaluate the impact of the alternative control on the alcoholic fermentation and wine composition.

RESULTS

The major compound of E. staigeriana EO were citral 30.91% (19.74% geranial, 11.17% neral), 1.8-cineole (24.59%) and limonene (19.47%), while 1.8-cineole represented 68.26% of E. globulus EO. The two EOs showed in vitro antifungal activity against both pathogens. Eucalyptus staigeriana EO exhibited the highest activity inhibiting mycelial growth (MG) and conidial germination at 0.5 μL mL^-1 . Moreover, this EO was able to reduce the incidence and severity of grey rot caused by B. cinerea and the severity of ripe rot caused by C. acutatum The alternative control did not significantly influence alcoholic fermentation, the physicochemical characteristics, and the volatile composition of wines.

CONCLUSION

These results are promising and indicate that E. staigeriana EO might be further investigated as a natural alternative for the control of fungal rots on wine grapes. © 2019 Society of Chemical Industry.

Chemical composition and sensory evaluation of wines produced with different Moscato varieties

Moscato grapes give very aromatic musts and wines, characterized by the presence of monoterpenoids. The Farroupilha region situated in the highlands of South Brazil, is responsible for 50% of Brazilian Moscato wines production, and obtained its Geographical Indication (GI) in 2015. Brazilian Moscato wines are produced with several varieties, mainly Moscato Branco, Moscato Bianco R2 and Moscato Giallo. The objective of this study was to characterize the aromatic profile of wines produced with the three varieties. Microvinifications were conducted with grapes collected in three vineyards located in Farroupilha. Volatile compounds were evaluated using gas chromatography, and sensory characteristics were determined by a panel of enologists using a specific descriptive chard. Moscato Giallo wines exhibited the highest concentrations of ethyl acetate, 2-phenylethanol, isoamyl acetate, linalool, and α-terpineol; Moscato R2 wines showed the highest concentrations of ethyl decanoate and nerol, while Moscato Branco wines, the most representative variety of Brazilian sparkling Moscato wines, exhibited the highest concentrations of ethanal and ethyl hexanoate, and intermediary concentrations of the other compounds. In sensory analysis, the three varieties exhibited pear, pitanga, rosemary, and citric fruits aromas, but in general, Moscato Giallo and Moscato R2 were more intense, while Moscato Branco showed the highest acidity.

Colletotrichum species associated to ripe rot disease of grapes in the “Serra Gaucha” region of Southern Brazil

Ripe rot disease caused by Colletotrichum (Glomerella) has become a serious problem for viticulture in Southern Brazil. Global warming contributes to the increase of this devastating and difficult to control disease. Several species of Colletotrichum, with different phytopathological characteristics, have been associated with ripe rot disease in different viticultural regions. In this article, a total of 63 fungi were isolated from grapes showing symptoms of ripe rot disease, and classified by sequencing of ITS region, and compared with the sequences deposited in GenBank. The isolates were included in three clades of Colletotrichum: 84.1% belonged to the “gloeosporioides” clade, 3.2% to the “boninense” clade, and 12.7% to the “acutatum” clade. Of the 53 isolates included in the “gloeosporioides” clade, 44.4% were classified as C. viniferum/C. ampelinum, 37.1% as C. fruticola, 13.0% as C. kahawae and 5.5% as a species related to C. fruticola. In turn, the two isolates of the “boninense” clade were classified as C. kartii/C. phyllanthi, and the six “acutatum” isolates were similar to C. acutatum and C. nymphaeae reference materials. The identified species were previously linked to ripe rot disease in other viticulture regions of the world, but the frequency of some species in southern Brazil is particularly different.

Extrinsic and Intrinsic Apoptotic Responses Induced by Shiitake Culinary-Medicinal Mushroom Lentinus edodes (Agaricomycetes) Aqueous Extract against a Larynx Carcinoma Cell Line

Cumulative evidence from research studies has shown that the shiitake culinary-medicinal mushroom, Lentinus edodes, is an excellent source of natural antitumor agents and is capable of inhibiting cancer cell growth. However, the cell signaling pathway that leads tumor cells to apoptosis is not well understood because many chemical compounds may be acting. This study investigated the chemopreventive effects of an L. edodes aqueous extract on human HEp-2 epithelial larynx carcinoma cells and normal human MRC-5 lung fibroblasts by identifying proliferative and apoptotic pathways. The chemical characterization of the dry powder was assessed by high-performance liquid chromatography. Antiproliferative and proapoptotic effects induced by the extract were evaluated by assessing proliferative markers, cell sorting through flow cytometry, and expression levels of apoptotic proteins with Western blotting. The results suggest that inhibition of cell proliferation was more prominent in HEp-2 than in MRC-5 cells. Cell death analysis showed the appearance of cell populations in the sub-G1 phase, with late apoptotic signal increased in a dose-dependent manner. In addition, the aqueous extract induced depolarization of mitochondria, activating the generation of intracellular reactive oxygen species in HEp-2 cells. These observations suggest that L. edodes extract may exert a chemopreventive effect, regulating mitotic induction of apoptogenic signals. These findings highlight the mushroom's pharmacological potential in cancer treatment.

BacPP: a web-based tool for Gram-negative bacterial promoter prediction

Bacterial Promoter Prediction (BacPP) is a tool used to predict given sequences as promoters of Gram-negative bacteria according to the σ factor that recognizes it. The first version of BacPP was implemented in Python language in a desktop version without a friendly interface. For this reason, a web version of BacPP is now available with the purpose of improving its usability and availability. The present paper describes the implementation of the web version of this tool, focusing on its software architecture and user functionalities. The software is available at www.bacpp.bioinfoucs.com/home.

Effect of different liming levels on the biomass production and essential oil extraction yield of Cunila galioides Benth

Poejo is an aromatic and medicinal plant native to highland areas of south Brazil, in acid soils with high Al3+ concentration. The main objective of the present work was to evaluate the effect of liming on the extraction yield of essential oil of three chemotypes of poejo (Cunila galioides Benth). For this purpose, the experiments were performed in a greenhouse, using 8-litre pots. The treatments were four dosages of limestone (0, 3.15, 12.5, and 25 g.L-1) and a completely random experimental design was used, with four replications and three chemotypes, set up in a 3 × 4 factorial arrangement. The parameters evaluated were dry weight of aerial parts, essential oil content and chemical composition of essential oil. Results showed that liming affects the biomass production, essential oil yield and chemical composition, with cross interaction verified between chemotype and limestone dosage. For the higher dosage lower biomass production, lower yield of essential oil as well as the lowest content of citral (citral chemotype) and limonene (menthene chemotype) was observed. In the ocimene chemotype, no liming influence was observed on the essential oil yield and on the content of major compounds. The dosage of 3.15 g.L-1 can be considered the best limestone dosage for the production of poejo for the experimental conditions evaluated.

A preliminary phylogeny of the genus Cunila D. Royen ex L. (Lamiaceae) based on ITS rDNA and trnL-F regions

Cunila species are aromatic and medicinal plants commonly employed in folk medicine. This genus is distributed in North America and in southern South America. The species that occur in southern South America are classified into three botanical sections: Incanae, Incisae and Spicatae. The present study uses a phylogenetic approach to study the genetic relationship among the South and North American Cunila species, aiming to test the monophyly of the genus in its traditional circumscription. The results based on sequencing from nuclear (ITS rDNA) and chloroplast (trnL-F) sets did not agree with the traditional circumscription of the genus. These data, based on maximum parsimony, maximum likelihood and Bayesian analyses, point to the non-monophyletic status of Cunila, since the genus was separated into three segregated clades: (1) A South American subshrub clade formed by the species of the botanical section Spicatae, (2) a South American shrub clade that includes the species of the botanical sections Incanae and Incisae, and (3) a North American Cunila clade.

Polymorphism in the MSX1 gene in a family with upper lateral incisor agenesis

OBJECTIVE

The MSX1 gene plays a key role in odontogenesis regulation, particularly during early stages. Since only a few genetic variants have thus far been associated with non-syndromic tooth agenesis, we screened for mutations in this gene, aiming to detect a relationship between genotype and phenotype.

DESIGN

The sample consisted of one proband with non-syndromic hypodontia involving upper lateral incisors, three relatives and ten unaffected controls. The proband and two affected relatives showed the same phenotype. DNA was extracted from buccal epithelial cells, and direct sequencing was performed. The two exons of MSX1 were first sequenced in the proband. When an alteration was detected, his relatives were investigated by the same method.

RESULTS

We identified the known polymorphism *6C>T in the homozygous state in all three affected family members. The unaffected father was heterozygous and ten control samples were negative for the *6C>T polymorphism.

CONCLUSIONS

The *6C>T polymorphism, when homozygous, may contribute to agenesis of upper lateral incisors. However, since the *6C>T polymorphism is quite common, additional genes must be involved in this phenotype.

A combined enrichment/polymerase chain reaction based method for the routine screening of Streptococcus agalactiae in pregnant women

Group B Streptococcus (GBS) is the most common cause of life-threatening infection in neonates. Guidelines from CDC recommend universal screening of pregnant women for rectovaginal GBS colonization. The objective of this study was to compare the performance of a combined enrichment/PCR based method targeting the atr gene in relation to culture using enrichment with selective broth medium (standard method) to identify the presence of GBS in pregnant women. Rectovaginal GBS samples from women at ≥36 weeks of pregnancy were obtained with a swab and analyzed by the two methods. A total of 89 samples were evaluated. The prevalence of positive results for GBS detection was considerable higher when assessed by the combined enrichment/PCR method than with the standard method (35.9% versus 22.5%, respectively). The results demonstrated that the use of selective enrichment broth followed by PCR targeting the atr gene is a highly sensitive, specific and accurate test for GBS screening in pregnant women, allowing the detection of the bacteria even in lightly colonized patients. This PCR methodology may provide a useful diagnostic tool for GBS detection and contributes for a more accurate and effective intrapartum antibiotic and lower newborn mortality and morbidity.

Effect of aluminum concentration on growth and secondary metabolites production in three chemotypes of Cunila galioides Benth. medicinal plant

Medicine plants play an important role in public health, especially in developing countries, and among them Cunila galioides Benth. is a naturally occurring medicinal and aromatic plant native from south Brazil. Flavonoids, present in significant amounts in some species of Cunila sp., possess several properties and its content may be affected by aluminum stress. In this context, the aim of this work was to assess the influence of different levels of aluminum in nutrient solution on the growth and content of essential oils and flavonoids in three chemotypes of Cunila galioides. The plant parameters evaluated were aerial dry matter, dry root matter, root length, root score, calcium and aluminum concentrations in the vegetable tissue, flavonoids content as well as essential oil yield and its major components concentration. Results showed that the addition of 30.0 mg.L--1 of Al3+ to the nutrient solution leads to a decrease of all agronomic parameters evaluated with losses in the cultivation yield for the greatest concentration studied. The André da Rocha population was found to be the most tolerant to aluminum while Bom Jardim da Serra was the most sensitive. The aluminum concentration did not influence the extraction yield as well as the content of major components in the oils. The concentration of flavonoids increased significantly for the populations tolerant to aluminum concentration in the nutrient solution, thus indicating a relationship between tolerance and flavonoids production, which may be an interesting characteristic from the medicinal point of view.

Nosocomial and community infections due to class A extended-spectrum β-lactamase (ESBLA)-producing Escherichia coli and Klebsiella spp. in southern Brazil

OBJECTIVES

To determine the prevalence of class A extended spectrum β-lactamases (ESBL)-producing Escherichia coli and Klebsiella spp., and to investigate clonality among ESBL-producing isolates of nosocomial and community infections.

METHODS

The study involved 354 nosocomial infections samples and 992 community infections samples, obtained between 2003 and 2006 at Caxias do Sul, RS. The detection of ESBL was performed by the disk-diffusion test. Presence of blaCTX-M, blaSHV and blaTEM β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis analysis.

RESULTS

Higher frequency of ESBL-producing isolates were detected among nosocomial samples of E. coli (6.7%) and Klebsiella (43.7%), than those obtained from community infections (0.4% and 2.6%). blaTEM and blaCTX were the most prevalent ESBL gene families in both E. coli and Klebsiella isolates. Different pulsotypes were obtained among ESBL-producing E. coli and 11 clones for Klebsiella spp., which occurred over the years and in different hospital wards. Among ESBL-producing K. pneumoniae, 74.3% transferred ESBL genes by conjugation and exhibited concomitant decreased aminoglycosides susceptibility.

CONCLUSION

ESBL-producing E. coli, and especially K. pneumoniae are essentially a nosocomial problem, and their dissemination to the community is relatively limited. The great genetic variability observed among ESBL-producing bacteria indicates polyclonal spread and high transference of ESBL genes between bacteria in the hospital environment. This information is of paramount importance for nosocomial infection control.

Diversity of extracellular proteases among Aeromonas determined by zymogram analysis

AIMS

The current research was aimed at comparing extracellular proteolytic activities and zymogram profiles among Aeromonas spp.

METHODS AND RESULTS

Extracellular proteases of 47 strains of Aeromonas were analyzed by substrate (casein and gelatin) co-polymerized SDS-PAGE, and caseinolytic activity was determined using azocasein. Large variation on caseinolytic activity was evidenced. In general, the caseinolytic activity of Aeromonas hydrophila strains was significantly higher than that of other Aeromonas species. Several caseinolytic and gelatinolytic profiles were detected in Aeromonas. Cluster analysis allowed separating Aeromonas strains in four and three groups, based on their caseinolytic and gelatinolytic profiles, respectively. Although not specific patterns were evident, most Aer. hydrophila strains were clustered together and differed from Aeromonas caviae strains. The main caseinases of Aer. hydrophila were a serine protease with an apparent molecular weight (AMW) of 56 kDa and a metalloprotease with AMW of 22 kDa. Gelatinase profiles were characterized by the presence of high molecular weight metalloproteases (84 and 93 kDa), although the most active enzyme was a serine protease with AMW of 56 kDa. Other new caseinases and gelatinases were detected in specific Aeromonas strains.

CONCLUSIONS

Aeromonas strains exhibited several extracellular proteolytic profiles, with a larger inter than intraspecific variation. Moreover, zymogram analyses allowed identifying new caseinases and gelatinases in Aeromonas.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the intra- and interspecific variation of proteolytic profiles in Aeromonas determined by zymogram analysis, including the detection of new caseinases and gelatinases in this genus.

Genetic diversity and conservation of native populations of Maytenus Ilicifolia Mart. ex Reiss

The aim of this work was to analyze genetic variability in 18 populations of Maytenus ilicifolia, and representatives of Maytenus aquifolia and Maytenus evonymoidis, collected in the states of Mato Grosso do Sul, Paraná, Santa Catarina and Rio Grande do Sul, using RAPD molecular markers. Considering total samples of the three species, 263 amplified fragments were identified, of which 72.2% showed to be polymorphous. The index of similarity (Jaccard coefficient) was on average 0.64 between M. ilicifolia and M. aquifolia; 0.47 between M. ilicifolia and M. evonymoidis; and 0.44 between M. aquifolia and M. evonymoidis. The analysis of groupings by the UPGMA algorithm allowed to clearly separate the three analyzed species. In determining the variability in M. ilicifolia, 222 bands were identified, on average 11.1 bands per primer, being 43.2% polymorphous. The index of similarity (Jaccard coefficient) in the bulks of each population in M. ilicifolia was, on average, 0.92 and the index of similarities among the populations was 0.83. The analysis of groupings with the UPGMA algorithm and the analysis of the main coordination (PCO), allowed the separation of the analyzed populations into three groups, the populations from the south of Rio Grande do Sul and the population from Mato Grosso do Sul standing out. A relation between the groupings found and the edaphoclimatic conditions of the collecting places was observed.

Genetic variation among South Brazilian accessions of Lippia alba Mill. (Verbenaceae) detected by ISSR and RAPD markers

Twenty-seven accessions of Lippia alba Mill. collected in Rio Grande do Sul state, Brazil, were analysed by ISSR and RAPD markers to evaluate their genetic variability and relationships. Six ISSR primers and four RAPD primers generated 120 amplified fragments, most of which were polymorphics. The overall genetic variability among accessions was very high when compared with other plant species. The hierarchical analysis of molecular data (UPGMA) showed low relationship between accessions, and no grouping between accessions of the same chemotype. Canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. Both ISSR and RAPD markers were efficient to address the genetic diversity of L. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species.

Can Nep1-like proteins form oligomers?

Nep1-like proteins (NLPs) are a novel family of microbial elicitors of plant necrosis that induce a hypersensitive-like response in dicot plants. The spatial structure and role of these proteins are yet unknown. In a paper published in BMC Plant Biology (2008; 8:50) we have proposed that the core region of Nep1-like proteins (NLPs) belong to the Cupin superfamily. Based on what is known about the Cupin superfamily, in this addendum to the paper we discuss how NLPs could form oligomers.

Cupin: a candidate molecular structure for the Nep1-like protein family

BACKGROUND

NEP1-like proteins (NLPs) are a novel family of microbial elicitors of plant necrosis. Some NLPs induce a hypersensitive-like response in dicot plants though the basis for this response remains unclear. In addition, the spatial structure and the role of these highly conserved proteins are not known.

RESULTS

We predict a 3d-structure for the beta-rich section of the NLPs based on alignments, prediction tools and molecular dynamics. We calculated a consensus sequence from 42 NLPs proteins, predicted its secondary structure and obtained a high quality alignment of this structure and conserved residues with the two Cupin superfamily motifs. The conserved sequence GHRHDWE and several common residues, especially some conserved histidines, in NLPs match closely the two cupin motifs. Besides other common residues shared by dicot Auxin-Binding Proteins (ABPs) and NLPs, an additional conserved histidine found in all dicot ABPs was also found in all NLPs at the same position.

CONCLUSION

We propose that the necrosis inducing protein class belongs to the Cupin superfamily. Based on the 3d-structure, we are proposing some possible functions for the NLPs.

Intra and inter populational genetic variability in Maytenus ilicifolia Mart. ex Reiss. 1861, through RAPD markers

Maytenus ilicifolia is a medicinal plant largely used in the South Brazilian folk medicine. The aim of this study was to quantify the intra and inter populational genetic variability in three populations of M. ilicifolia, focusing on the genetic conservation of this species, which has been threatened by anthropic action. RAPD (Random Amplified Polymorphic DNA) markers were used to analyze 30 plants of each of the three populations collected in the Alto Uruguai Gaúcho region. Fourteen selected primers generated a total of 158 bands, 71.5% of which were polymorphic. The comparison of Jaccards distances showed that the intra populational variation was higher than the inter populational variability, and cluster analysis allowed the separation of the three populations. Just 7.6% of the bands were specific of at least two populations. Data indicate that the analyzed M. ilicifolia populations represent a single genetic pool, and therefore any of the population thoroughly can represent the overall genetic variability of the species in the sampled region.

Endophytic yeasts and filamentous fungi associated with southern Brazilian apple(Malus domestica) orchards subjected to conventional, integrated or organic cultivation

Endophytic fungi were isolated from leaves, flowers and fruit of healthy apple trees (Malus domestica , Borkh.) growing in southern Brazilian orchards under three different cultivation systems (conventional, integrated and organic), during two vegetative cycles. The greatest total number of endophytic isolates was obtained from the orchards under organic cultivation when compared to integrated and conventional cultivation systems. Filamentous fungi from the genera Colletotrichum , Xylaria and Botryosphaeria were the most frequent ones and the most representative yeast genera were Sporobolomyces , Rhodotorula , Debaryomyces and Cryptococcus . It is suggested that some isolates may be used as indicators of the different management systems.

Mutagenic and antioxidant activities of Croton lechleri sap in biological systems

The sap of Croton lechleri Muell.-Arg (Euphorbiaceae), called Dragon's blood, is used in folk medicine as a cicatrizant, anti-inflammatory and to treat cancer. In this research, the antioxidant activity of Croton lechleri sap was evaluated against the yeast Saccharomyces cerevisiae and against maize plantlets treated with the oxidative agents apomorphine and hydrogen peroxide. The mutagenic activity of the sap was also analyzed using the Salmonella/microsome assay (Salmonella typhimurium TA97a, TA98, TA100, TA102, TA1535) and in cells of the yeast Saccharomyces cerevisiae. The results showed that Croton lechleri sap possesses significant antioxidant activity against the oxidative damages induced by apomorphine in Saccharomyces cerevisiae under all the conditions studied. However, in the case of hydrogen peroxide, antioxidant activity of the sap was detected only in cells in the stationary phase of growth. The sap was also able to protect cells of the maize plantlets from the toxic effect of apomorphine. This sap showed mutagenic activity for strain TA1535 of Salmonella typhimurium in the presence of metabolic activation and a weak mutagenic activity for strain TA98. These strains detect base pair substitutions and frameshift mutations, respectively. Mutagenicity was also observed in a haploid Saccharomyces cerevisiae strain XV185-14c for the lys1-1, his1-7 locus-specific reversion and hom3-10 frameshift mutations.

Production of a monoclonal antibody against Aeromonas hydrophila and its application to bacterial identification

AIMS

to develop a monoclonal antibody (MAb) for the rapid detection of Aeromonas hydrophila in human faeces.

METHODS AND RESULTS

A monoclonal antibody with strong specificity against Aer. hydrophila was obtained by the fusion of myeloma cells and splenocytes of a mouse immunized with vegetative cells of Aer. hydrophila ATCC 7966, followed by a two-step selection against other species of the genera. ELISA analyses revealed that MAb 5F3 strongly reacts with all the Aer. hydrophila strains evaluated, showing a just basal reactivity against other species of the genera, especially Aer. sobria and Aer. caviae.

CONCLUSIONS

MAb 5F3 was characterized as an IgG that recognized a polypeptide of approximately 110 kDa.

SIGNIFICANCE AND IMPACT OF THE STUDY

This MAb could be used to detect Aer. hydrophila in human stool samples.

Correlation between the chemical and genetic relationships among commercial thyme cultivars

The essential oil composition and genetic variability of six commercial cultivars of thyme (Thymus vulgaris L.), a Mediterranean medicinal and aromatic plant, were analyzed by GC-MS and randomly amplified polymorphic DNA (RAPD), respectively. All evaluated cultivars belong to the thymol chemotype, with differences in the concentrations of thymol, gamma-terpinene, p-cymene, and other minor components. The comparison of the oil components concentration by multivariate analysis allowed separation of the cultivars into two groups. All of the cultivars exhibited characteristic RAPD patterns that allowed their identification. On the basis of the RAPD patterns, the cultivars could be divided into two clusters, which coincides with results obtained by oil GS-MS analysis, with a correlation coefficient of -0.779.

Growth of Aeromonas species on increasing concentrations of sodium chloride

The growth of 16 strains of Aeromonas, representing 12 species of the genera, were examined at different salt levels (0-1.71 M NaCl). All the strains grew on media with 0.34 M NaCl, and nine on media with 0.68 M. Two strains, Aer. enteropelogenes and Aer. trota, were able to grow on media with 0.85 M and 1.02 M NaCl, respectively. Comparison of the growth curves of Aer. hydrophila ATCC7966 and Aer. trota ATCC 49657 on four concentrations of NaCl (0.08, 0.34, 0.68 and 1.02 M) confirm the high tolerance of Aer. trota, and indicate that high concentrations of salt increase the lag time and decrease the maximum growth rate. However, both strains were able to grow, slowly, in at least 0.68 M NaCl, a sodium chloride concentration currently used as food preservative.

Use of seed protein polymorphism for discrimination of improvement level and geographic origin of upland rice cultivars

Grain proteins from 58 Brazilian and nine Japanese upland rice cultivars (Oryza sativa L.) were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric scanning of the electrophoretic profiles permitted the estimation of the relative concentration of 16 protein fractions, which were used as variables for the calculation of Fisher's canonical discriminating functions. Significant differences between mean values of protein fractions were useful in distinguishing Brazilian and Japanese cultivars, as well as improved and non-improved Brazilian rice cultivars in scattered plots. Electrophoretically detectable protein polymorphism in rice grain can indicate geographic origin as well as breeding improvement level of a cultivar. Improved cultivars were those released by plant breeding institutes.