The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

The role of arbuscular mycorrhizal fungi in the alleviation of cadmium stress in cereals: A multilevel meta-analysis

The symbiotic relationships between crop species and arbuscular mycorrhizal fungi (AMF) are crucial for plant health, productivity, and environmental sustainability. The roles of AMF in reducing crop stress caused by cadmium (Cd) toxicity and in the remediation of Cd-contaminated soil are not fully understood. Here we report on a meta-analysis that sought to identify the functions of AMF in cereals under Cd stress. A total of 54 articles published between January 1992 and September 2022 were used to create the dataset, which provided 7216 data sets on mycorrhizal cereals under Cd stress examined. AMF effects on colonization rate, biomass, physiological level, nutritional level, and plant Cd level were measured using the logarithmic response ratio (Ln R). The results showed that AMF overall greatly reduced 5.14 - 33.6 % Cd stress on cereals in greenhouse experiments under controlled conditions. AMF colonization significantly stimulated crop biomass by 65.7 %, boosted the formation of photosynthetic pigments (23.2 %), and greatly increased plant nitrogen (24.8 %) and phosphorus (58.4 %) uptake. The dilution effect of mycorrhizal plants made the Cd concentration decline by 25.2 % in AMF plants compared to non-mycorrhizal ones. AMF also alleviated Cd stress by improving osmotic regulators (soluble protein, sugar, and total proline, from 14.8 to 36.0 %) and lowering the membrane lipid peroxidation product (MDA, 12.9 %). Importantly, the results from the random forest and model selection analysis demonstrated that crop type, soil characteristics, chemical form, and Cd levels were the main factors determining the function of AMF in alleviating Cd stress. Additionally, there was a significant interaction between AMF colonization rate and Cd addition, but their interactive effect was less than the colonization rate alone. This meta-analysis demonstrated that AMF inoculation could be considered as a promising strategy for mitigation of Cd stress in cereals.

The Potential of Allelochemicals from Microalgae for Biopesticides

Improvements in agricultural productivity are required to meet the demand of a growing world population. Phytopathogens, weeds, and insects are challenges to agricultural production. The toxicity and widespread application of persistent synthetic pesticides poses a major threat to human and ecosystem health. Therefore, sustainable strategies to control pests are essential for agricultural systems to enhance productivity within a green paradigm. Allelochemicals are a less persistent, safer, and friendly alternative to efficient pest management, as they tend to be less toxic to non-target organisms and more easily degradable. Microalgae produce a great variety of allelopathic substances whose biocontrol potential against weeds, insects, and phytopathogenic fungi and bacteria has received much attention. This review provides up-to-date information and a critical perspective on allelochemicals from microalgae and their potential as biopesticides.

Development of Microalgae Biodiesel: Current Status and Perspectives

Microalgae are regarded as a promising source of biodiesel. In contrast with conventional crops currently used to produce commercial biodiesel, microalgae can be cultivated on non-arable land, besides having a higher growth rate and productivity. However, microalgal biodiesel is not yet regarded as economically competitive, compared to fossil fuels and crop-based biodiesel; therefore, it is not commercially produced. This review provides an overall perspective on technologies with the potential to increase efficiency and reduce the general costs of biodiesel production from microalgae. Opportunities and challenges for large-scale production are discussed. We present the current scenario of Brazilian research in the field and show a successful case in the research and development of microalgal biodiesel in open ponds by Petrobras. This publicly held Brazilian corporation has been investing in research in this sector for over a decade.

Arbuscular Mycorrhizal Fungi Alleviate Low Phosphorus Stress in Maize Genotypes with Contrasting Root Systems

Soil available phosphorus (P) is one of the main factors limiting plant growth and yield. This study aimed to determine the role of arbuscular mycorrhizal fungi (AMF) in P-use efficiency in two maize genotypes with contrasting root systems in response to low P stress. Maize genotypes small-rooted Shengrui 999 and large-rooted Zhongke 11 were grown in rhizoboxes that were inoculated with or without AMF (Funneliformis mosseae) under low P (no added P) or optimal P (200 mg kg^-1) for 53 days. Low P stress significantly inhibited shoot and root growth, photosynthesis, tissue P content, and root P concentration in both genotypes. Shengrui 999 was more tolerant to P stress with less reduction of these traits compared to Zhongke 11. Shengrui 999 had a higher AMF infection rate than Zhongke 11 at both P levels. Under P deficit, inoculation with AMF significantly promoted plant growth and P uptake in both genotypes with more profound effects seen in Zhongke 11, whilst Shengrui 999 was more dependent on AMF under optimal P. Low P stress inhibited the growth and physiological attributes of both genotypes. The small-rooted Shengrui 999 was more tolerant to low P than Zhongke 11. Inoculation with AMF alleviates low P stress in both genotypes with a more profound effect on Zhongke 11 at low P and on Shengrui 999 at high P conditions.

Aeromonas allosaccharophila Strain AE59-TE2 Is Highly Antagonistic towards Multidrug-Resistant Human Pathogens, What Does Its Genome Tell Us?

Multidrug-resistant bacteria are of critical importance and a problem for human health and food preservation; the discovery of new antimicrobial substances to control their proliferation is part of the solution. This work reports on 57 antagonistic Aeromonas strains, of which 38 strains were antagonistic towards problematic human pathogens. The genome of the most antagonistic strain was sequenced and identified as Aeromonas allosaccharophila. Its genome was fully annotated and mined for genes that might explain that activity. Strain AE59-TE was antagonistic toward clinically relevant gram-negative and gram-positive multidrug-resistant bacteria, including Klebsiella pneumoniae KPC, Escherichia coli ESBL, Salmonella typhimurium, and Staphylococcus aureus MRSA. Strain AE59-TE2 was identified by multilocus sequence analysis. Genome mining identified four genes homologous to the bacteriocin, zoocin A from Streptococcus equi and a gene 98% similar to cvpA linked to colicin V production. A. allosaccharophila strain AE59-TE2 produced antimicrobial activity against a broad range of bacteria, including important gram-negative bacteria, not typically targeted by bacteriocins. Herewere described novel zoocin genes that are promising for industrial applications in the food and health sectors. Interesting and important antagonistic activity is described combined with the first detailed genomic analysis of the species Aeromonas allosaccharophila.

Methane emissions and rumen metabolite concentrations in cattle fed two different silages

In this study, 18 animals were fed two forage-based diets: red clover (RC) and grass silage (GS), in a crossover-design experiment in which methane (CH₄) emissions were recorded in respiration chambers. Rumen samples obtained through naso-gastric sampling tubes were analysed by NMR. Methane yield (g/kg DM) was significantly lower from animals fed RC (17.8 ± 3.17) compared to GS (21.2 ± 4.61) p = 0.008. In total 42 metabolites were identified, 6 showing significant differences between diets (acetate, propionate, butyrate, valerate, 3-phenylopropionate, and 2-hydroxyvalerate). Partial least squares discriminant analysis (PLS-DA) was used to assess which metabolites were more important to distinguish between diets and partial least squares (PLS) regressions were used to assess which metabolites were more strongly associated with the variation in CH₄ emissions. Acetate, butyrate and propionate along with dimethylamine were important for the distinction between diets according to the PLS-DA results. PLS regression revealed that diet and dry matter intake are key factors to explain CH₄ variation when included in the model. Additionally, PLS was conducted within diet, revealing that the association between metabolites and CH₄ emissions can be conditioned by diet. These results provide new insights into the methylotrophic methanogenic pathway, confirming that metabolite profiles change according to diet composition, with consequences for CH₄ emissions.

Sulphate-reducing bacterial community structure from produced water of the Periquito and Galo de Campina onshore oilfields in Brazil

Sulphate-reducing bacteria (SRB) cause fouling, souring, corrosion and produce H2S during oil and gas production. Produced water obtained from Periquito (PQO) and Galo de Campina (GC) onshore oilfields in Brazil was investigated for SRB. Produced water with Postgate B, Postgate C and Baars media was incubated anaerobically for 20 days. DNA was extracted, 16S rDNA PCR amplified and fragments were sequenced using Illumina TruSeq. 4.2 million sequence reads were analysed and deposited at NCBI SAR accession number SRP149784. No significant differences in microbial community composition could be attributed to the different media but significant differences in the SRB were observed between the two oil fields. The dominant bacterial orders detected from both oilfields were Desulfovibrionales, Pseudomonadales and Enterobacteriales. The genus Pseudomonas was found predominantly in the GC oilfield and Pleomorphominas and Shewanella were features of the PQO oilfield. 11% and 7.6% of the sequences at GC and PQO were not classified at the genus level but could be partially identified at the order level. Relative abundances changed for Desulfovibrio from 29.8% at PQO to 16.1% at GC. Clostridium varied from 2.8% at PQO and 2.4% at GC. These data provide the first description of SRB from onshore produced water in Brazil and reinforce the importance of Desulfovibrionales, Pseudomonadales, and Enterobacteriales in produced water globally. Identifying potentially harmful microbes is an important first step in developing microbial solutions that prevent their proliferation.

Coral microbiome manipulation elicits metabolic and genetic restructuring to mitigate heat stress and evade mortality

Beneficial microorganisms for corals (BMCs) ameliorate environmental stress, but whether they can prevent mortality and the underlying host response mechanisms remains elusive. Here, we conducted omics analyses on the coral Mussismilia hispida exposed to bleaching conditions in a long-term mesocosm experiment and inoculated with a selected BMC consortium or a saline solution placebo. All corals were affected by heat stress, but the observed "post-heat stress disorder" was mitigated by BMCs, signified by patterns of dimethylsulfoniopropionate degradation, lipid maintenance, and coral host transcriptional reprogramming of cellular restructuration, repair, stress protection, and immune genes, concomitant with a 40% survival rate increase and stable photosynthetic performance by the endosymbiotic algae. This study provides insights into the responses that underlie probiotic host manipulation. We demonstrate that BMCs trigger a dynamic microbiome restructuring process that instigates genetic and metabolic alterations in the coral host that eventually mitigate coral bleaching and mortality.

Decolorization and detoxification of different azo dyes by Phanerochaete chrysosporium ME-446 under submerged fermentation

Azo dyes are widely used in the textile industry due to their resistance to light, moisture, and oxidants. They are also an important class of environmental contaminant because of the amount of dye that reaches natural water resources and because they can be toxic, mutagenic, and carcinogenic. Different technologies are used for the decolorization of wastewater containing dyes; among them, the biological processes are the most promising environmentally. The aim of this study was to evaluate the potential of Phanerochaete chrysosporium strain ME-446 to safely decolorize three azo dyes: Direct Yellow 27 (DY27), Reactive Black 5 (RB5), and Reactive Red 120 (RR120). Decolorization efficiency was determined by ultraviolet-visible spectrophotometry and the phytotoxicity of the solutions before and after the fungal treatment was analyzed using Lactuca sativa seeds. P. chrysosporium ME-446 was highly efficient in decolorizing DY27, RB5, and RR120 at 50 mg L-1, decreasing their colors by 82%, 89%, and 94% within 10 days. Removal of dyes was achieved through adsorption on the fungal mycelium as well as biodegradation, inferred by the changes in the dyes' spectral peaks. The intensive decolorization of DY27 and RB5 corresponded to a decrease in phytotoxicity. However, phytotoxicity increased during the removal of color for the dye RR120. The ecotoxicity tests showed that the absence of color does not necessarily translate to an absence of toxicity.

Physiological and molecular responses of Setaria viridis to osmotic stress

Drought-tolerant species, such as Setaria viridis, a C₄ model plant, make physiological and biochemical adjustments water limitation and recover from the stress upon its release. We investigated S. viridis (A10.1 accession) responses to continuing osmotic stress. The osmotic stress was imposed using polyethylene glycol (PEG) 8000 (7.5%) for 10 days. Morphological traits and stomatal conductance were measured daily for the 10 days. On days 6 and 10, the following traits were measured separately for root and shoot: relative water content (RWC), osmotic potential (OP), electrolytic leakage (EL), and proline content. qPCR analysis was used to evaluate the expression of five selected genes in roots (SvLEA, SvDREB1C, SvPIP2-1, SvHSP20, and SvP5CS2), and chlorophyll a fluorescence was measured on three key days. The morphological data demonstrated a drastic reduction in shoot biomass as an effect of water deficit caused by the osmotic stress. Shoot biomass reduction could be associated with putative ABA-dependent signaling involved in SvDREB1C expression. Stomatal conductance and photosynthesis were severely affected up until day 6, however, stomatal conductance and some photosynthetic parameters such as F_V/F_M, ABS/RC, and DI₀/RC showed total or slight recovery on day 10. Root EL decreased in treated plants suggesting an investment in membrane protection by osmoregulator expression such as dehydrin (SvLEA) and proline (SvP5CS2) genes. Our data suggest that S. viridis exhibited a partial recovery from an imposed and constant osmotic stress within 10 days.

Nuclear Magnetic Resonance to Detect Rumen Metabolites Associated with Enteric Methane Emissions from Beef Cattle

This study presents the application of metabolomics to evaluate changes in the rumen metabolites of beef cattle fed with three different diet types: forage-rich, mixed and concentrate-rich. Rumen fluid samples were analysed by ¹H-NMR spectroscopy and the resulting spectra were used to characterise and compare metabolomic profiles between diet types and assess the potential for NMR metabolite signals to be used as proxies of methane emissions (CH₄ in g/kg DMI). The dataset available consisted of 128 measurements taken from 4 experiments with CH₄ measurements taken in respiration chambers. Predictive modelling of CH₄ was conducted by partial least squares (PLS) regression, fitting calibration models either using metabolite signals only as predictors or using metabolite signals as well as other diet and animal covariates (DMI, ME, weight, BW^0.75, DMI/BW^0.75). Cross-validated R² were 0.57 and 0.70 for the two models respectively. The cattle offered the concentrate-rich diet showed increases in alanine, valerate, propionate, glucose, tyrosine, proline and isoleucine. Lower methane yield was associated with the concentrate-rich diet (p < 0.001). The results provided new insight into the relationship between rumen metabolites, CH₄ production and diets, as well as showing that metabolites alone have an acceptable association with the variation in CH₄ production from beef cattle.

Fungal communities in oil contaminated mangrove sediments - Who is in the mud?

Mangroves are ecosystems located in tropical and subtropical regions of the world and are vital for coastal protection. Their unique characteristics make them hotspots for carbon cycling and biological diversity. Studies on isolated filamentous fungi and environmental and anthropogenic factors that influence sediments offer new understandings on how to preserve mangroves. Here we report on the filamentous fungi isolated from four mangroves. We correlated fungal community composition with sediment texture, polycyclic aromatic hydrocarbons concentration (oil pollution), pH, salinity, organic matter, total and thermotolerant coliforms (sewage pollution). In total we identified 34 genera and 97 species. The most polluted sites had highest species richness whereas the best preserved site showed the lowest species richness. Oil spill and sewage pollution were identified as the drivers of fungal community composition in the most polluted sites. We found very distinct fungal communities with no >5 species shared between any two mangrove sites.

The putative α/β-hydrolases of Dietzia cinnamea P4 strain as potential enzymes for biocatalytic applications

The draft genome of the soil actinomycete Dietzia cinnamea P4 reveals a versatile group of α/β-hydrolase fold enzymes. Phylogenetic and comparative sequence analyses were used to classify the α/β-hydrolases of strain P4 into six different groups: (i) lipases, (ii) esterases, (iii) epoxide hydrolases, (iv) haloacid dehalogenases, (v) C-C breaking enzymes and (vi) serine peptidases. The high number of lipases/esterases (41) and epoxide hydrolase enzymes (14) present in the relatively small (3.6 Mb) P4 genome is unusual; it is likely to be linked to the survival of strain P4 in its natural environment. Strain P4 is thus equipped with a large number of genes which would appear to confer survivability in harsh hot tropical soil. As such, this highly resilient soil bacterial strain provides an interesting genome for enzyme mining for applications in the field of biotransformations of polymeric compounds.

Microbial diversity in Brazilian mangrove sediments - a mini review

The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems.

Increased expression of keratinase and other peptidases by Candida parapsilosis mutants

Keratinases are enzymes of great importance involved in pathogenic processes of some fungi. They also have a widespread ecological role since they are responsible for the degradation and recycling of keratin. On the one hand, studying them furthers our knowledge of pathogenicity mechanisms, which has important implications for human health, and on the other hand, understanding their ecological role in keratin recycling has biotechnological potential. Here, a wild-type keratinolytic Candida parapsilosis strain isolated from a poultry farm was treated with ethyl methanesulfonate in order to generate mutants with increased keratinase activity. Mutants were then cultured on media with keratin extracted from chicken feathers as the sole source of nitrogen and carbon. Approximately 500 mutants were screened and compared with the described keratinolytic wild type. Three strains, H36, I7 and J5, showed enhanced keratinase activity. The wild-type strain produced 80 U/mL of keratinolytic activity, strain H36 produced 110 U/mL, strain I7, 130 U/mL, and strain J5, 140 U/mL. A 70% increase in enzyme activity was recorded for strain J5. Enzymatic activity was evaluated by zymograms with proteic substrates. A peptidase migrating at 100 kDa was detected with keratin, bovine serum albumin and casein. In addition, a peptidase with a molecular mass of 50 kDa was observed with casein in the wild-type strain and in mutants H36 and J5. Gelatinase activity was detected at 60 kDa. A single band of 35 kDa was found in wild-type C. parapsilosis and in mutants with hemoglobin substrate.

Specificity of a defined substrate method used to monitor balneability of tropical coastal waters impacted by polluted stormwater

Defined substrate (DS) is an alternative technique to monitoring the water quality based on species-specific enzyme activity. Although more sensitive and more specific than traditional media, there is some controversy over use in the warmer waters of tropical and subtropical environments, rich in organic matter and microorganism groups capable of interfering with results. The aim of this study was to test the specificity of DS method (Colilert, IDEXX) for detection of coliforms and Escherichia coli in stormwater seawater samples from a coastal city (Fortaleza, Brazil) compared to findings obtained with the multiple tube fermentation (MTF) method. The samples were collected from stormsewers and adjacent seashore locations. The most probable number (MPN) of total coliforms (TC), thermotolerant coliforms (TtC) and E. coli was determined and the selectivity of the enzymatic substrate medium in the seawater samples was tested. The MTF method showed samples from sampling points 1, 2 and 3 to be 13.3, 13.3 and 46.7%, respectively, above the legal cut-off value for coastal balneability. With the DS method, the corresponding figures were 60, 53.3 and 80% for E. coli. Overall, coliform levels were higher with the DS medium. Vibrios and aeromonads were isolated from E. coli-positive DS tubes.

Raw oysters can be a risk for infections

The aims of this study were to count and identify sucrose positive and negative vibrios isolated from cultivated Crassostrea rhizophorae oysters during their growing cycle. Every month for 12 months, 10 to 18 oysters were collected for study. Collections occurred at the Center for Studies of Coastal Aquaculture (CSCA), which is associated with the Institute of Marine Science, Labomar, located in Euzebio, Ceará, Brazil. Approximately 150 oysters and their intervalvular liquor were studied. Vibrio Standard Plates Counts (SPC) from oyster meat and their intervalvular liquor varied from 25 to 59,000,000 CFU/g. For most of the 12 months of the oysters' life, it was possible to identify Vibrio parahaemolyticus. Vibrio carchariae was identified in four collections. Among other isolated species, the most important, considering public health risks, was V. vulnificus, although only one strain was confirmed. We concluded that retail purchased oysters should never be eaten raw or undercooked because many species of the genus Vibrio are known to be pathogenic to humans and live naturally on and in shellfish throughout their life cycle.

Characterization of Aeromonas species isolated from an estuarine environment

Thirty water samples were collected, at two week intervals, from the estuary of the River Cocó. The aim was to characterize the presence, distribution and types of Aeromonas spp, in the estuary of the River Cocó, Ceara, Brazil (03°46’28.83’’S e 38°26’36.52’’S). Aeromonas were identified in 19 (63%) samples analyzed by plating and CFU counts. Presence/absence tests were positive for 11 (37%) of the samples resulting in the detection of Aeromonas in a total of 23 (77%) of samples. CFU counts varied from < 10 to 1.4 x 10⁴ CFU mL^-1. From the isolated strains seven species of Aeromonas were identified: A. caviae (29/69), A. veronii bv. sobria (13/69), A. veronii bv. veronii (8/69), A. trota (6/69), A. media (5/69), A. sobria (4/69) and A. hydrophila and Aeromonas sp. (2/69). Of the 38 strains tested, 23 (60%) showed resistance to at least one of the eight antimicrobials. Multiple resistance to antibiotics was observed in A. caviae, A. media , A. sóbria and A. veronii bv. sobria. Aeromonas caviae showed the highest multiple resistance, being resistant to four antibiotics. The presence of those microorganisms may contribute to the occurrence of gastroenteritis, mainly in children, since they are considered opportunists.

Identification of a Candida parapsilosis strain producing extracellular serine peptidase with keratinolytic activity

A yeast strain isolated from feather waste from a chicken processing plant was identified as Candida parapsilosis by biochemical tests and morphological studies. The yeast was able to grow in phosphate-buffered saline supplemented with 1% native feather as the sole carbon and nitrogen source. A keratin substrate was obtained from the feathers by dimethylsulphoxide extraction. A 20-fold concentrated culture supernatant from Candida parapsilosis grown on feathers was analysed by SDS-PAGE electrophoresis containing either 1% gelatin or 1% keratin as copolymerised substrates. The presence of a single band with an approximate molecular mass of 60 kDa with gelatinolytic and keratinolytic activities was observed. This proteolytic activity was fully inhibited by phenylmethylsulphonyl fluoride. These results suggest that the extracellular enzyme belongs to the serine peptidase class. This is the first report of an extracellular serine peptidase produced by C. parapsilosis with keratinolytic activity. The role of this enzyme in yeast-host interactions is discussed.

Streptomyces lunalinharesii sp. nov., a chitinolytic streptomycete isolated from cerrado soil in Brazil

A novel chitinolytic actinomycete isolated from a Brazilian cerrado soil, designated strain RCQ1071(T), was assigned to the genus Streptomyces on the basis of chemical and morphological characteristics. The almost-complete nucleotide sequence of the 16S rRNA gene of strain RCQ1071(T) was determined and also placed this strain in the genus Streptomyces. Phylogenetic analyses of 16S rRNA gene sequences showed that strain RCQ1071(T) formed a long branch in a group related to Streptomyces albulus, sharing approximately 98 % sequence similarity. Levels of DNA-DNA relatedness between strain RCQ1071(T) and members of this group, namely S. albulus DSM 40492(T), Streptomyces noursei DSM 40635(T) and Streptomyces yunnanensis DSM 41793(T), were 38.3, 27.8 and 46 %, respectively, strongly indicating that strain RCQ1071(T) was not a member of any of these species. The relatively long branch length within a stable clade together with the phenotypic data strongly supported that strain RCQ1071(T) represented a novel species. Based on the combination of physiological, phylogenetic and genomic data, strain RCQ1071(T) is suggested to represent a novel species of the genus Streptomyces, for which the name Streptomyces lunalinharesii sp. nov. is proposed. The type strain is RCQ1071(T) (=ATCC BAA-1231(T) =CIP 108852(T) =DSM 41876(T)).

Killer yeasts inhibit the growth of the phytopathogen Moniliophthora perniciosa, the causal agent of Witches' Broom disease

Fruit and soil yeasts isolated from the Amazon, Atlantic Rainforests and an organic farm were screened for killer activity against yeasts. Killer yeasts were then tested against the phytopathogen Moniliophthora perniciosa (syn. Crinipellis perniciosa) and a Dipodascus capitatus strain and a Candida sp strain inhibited its growth.

Who responds to aripiprazole in clinical practice? An observational study of combination versus monotherapy

We aimed to study aripiprazole, as monotherapy and combined with other antipsychotics, in routine clinical practice, to identify patients who had a favourable clinical response. We retrospectively identified all secondary care psychiatric patient records started on aripiprazole (n = 85). We assigned Clinical Global Impression scores to measure effectiveness. We examined demographic and clinical correlates of patients who improved (CGI Improvement scores < 5) versus those who did not improve (CGI > or = 5). 56 patients (66%) received aripiprazole as monotherapy, 29 patients (34%) in combination with other antipsychotics. 52 patients (62%) received a CGI 1-4 (minimally to very much improved), 32 patients (38%) a CGI > or = 5 (no change to very much worse). Patients who improved were less likely to have had previous or subsequent treatment with clozapine (p = 0.04). Discontinuation was due to agitation (35%), inefficacy (21%), nausea (18%) and worsening psychosis (12%). Combination with other antipsychotics resulted in less discontinuation and a lower maximum dose of aripiprazole. Aripiprazole was combined with other regular additional antipsychotics in 1/3rd of patients. Combination and monotherapy were clinically effective in around 60% of patients. Favourable response was associated with lack of treatment resistance. Agitation was the commonest reason for discontinuation.

Atrazine leaching through surface and subsurface of a tropical Oxisol

The fate of (14)C atrazine was investigated using microcosms and an undisturbed Red-Yellow Latossol (Oxisol) under simulated rainfall conditions of 200 mm water month(-1). Experiments were carried out using microcosm cores, the first with an uncovered surface soil; the second set with uncovered subsurface soil; the third with subsurface soil covered with 3 cm of cow manure and the last with subsurface soil covered with 5 cm of grass straw. Average values for the amount of atrazine leached after 60 days were as follows: surface soil 1.6%; subsurface 47.3%; subsurface plus manure 17.3% and subsurface plus straw 24.8%. In the surface soil, 53% of the (14)C atrazine remained within the upper 1 cm, while in the subsurface microcosms the atrazine was more evenly distributed. The authors report that surface soil was retained atrazine and its metabolites for 60 days. The addition of a straw or manure covering to exposed subsoil helped to retard atrazine leaching.

Antibacterial activity of GUAVA, Psidium guajava Linnaeus, leaf extracts on diarrhea-causing enteric bacteria isolated from Seabob shrimp, Xiphopenaeus kroyeri (Heller)

Guava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.

Peptidase profiles from non-albicans Candida spp. isolated from the blood of a patient with chronic myeloid leukemia and another with sickle cell disease

Candida lipolytica and Candida rugosa were isolated from blood samples from a patient with chronic myeloid leukemia (31 years old) and a patient with sickle cell disease (1-year-old), respectively. Isolates were grown for 48 h at 37 degrees C in either Sabouraud or tryptone soy broth (TSB). Peptidases were tested for using substrate sodium dodecyl sulfate-polyacrylamide gels with gelatin, casein, bovine serum albumin (BSA) or hemoglobin. Enzymography analyses were made on the following substrates: human albumin, IgG and human fibrinogen, which had been incubated with the concentrated supernatants. For C. lipolytica, a approximately 60-kDa gelatin-degrading serine proteolytic activity was found in the TSB supernantant as well as a metallopeptidase activity capable of hydrolysing human albumin, IgG and human fibrinogen. With C. rugosa, albumin, IgG and human fibrinogen substrates were degraded by an aspartyl-like peptidase activity. Supernatants from C. rugosa also showed three serine proteolytic activities towards gelatin (approximately 50 kDa, TSB), casein ( approximately 94 kDa, TSB) and BSA ( approximately 120-kDa, Sabouraud), in addition to a metallopeptidase capable of degrading casein ( approximately 110 kDa, Sabouraud). Little is known about peptidases of C. rugosa and C. lipolytica and this preliminary data may prove useful for future work on host-parasite relationship and antifungal agents.

Atrazine sorption and fate in a Ultisol from humid tropical Brazil

This study combined laboratory based microcosm systems as well as field experiments to evaluate the mobility of atrazine on a Ultisol under humid tropical conditions in Brazil. Results from sorption experiments fit to the Freundlich isotherm model [K(f) 0.99 mg kg(-1)/(mg l(-1))(1/n)], and indicate a low sorption capacity for atrazine in this soil and consequently large potential for movement by leaching and runoff. Microcosm systems using (14)C-atrazine to trace the fate of the applied herbicide, showed that 0.33% of the atrazine was volatilized, 0.25% mineralized and 6.89% was recorded in the leachate. After 60 d in the microcosms, 75% of the (14)C remained in the upper 5 cm soil layer indicating atrazine or its metabolites remained close to the soil surface. In field experiments, after 60 d, only 5% of the atrazine applied was recovered in the upper soil layers. In the field experiments atrazine was detected at a depth of 50 cm indicating leaching. Simulating tropical rain in field experiments resulted in 2.1% loss of atrazine in runoff of which 0.5% was adsorbed onto transported soil particles and 1.6% was in solution. Atrazine runoff was greatest two days after herbicide application and decreased 10 fold after 15 d. The use of atrazine on Ultisols, in the humid tropics, constitutes a threat to water quality, causing surface water and ground water pollution.

New group-specific 16S rDNA primers for monitoring foaming mycolata during saline waste-water treatment

Newly designed group-specific PCR primers for denaturing gradient gel electrophoresis (DGGE) were used to investigate foaming mycolata from a bioreactor treating an industrial saline waste-water. Genetic profiles on DGGE gels were different with NaCl at 1.65 and 8.24 g l(-1), demonstrating that mycolata community was affected by salinity. A semi-nested PCR strategy resulted in more bands in community genetic profiles than direct amplification. DNA sequencing of bands confirmed the efficacy of the novel primers with sequences recovered being most similar to foam producing mycolata. The new group-specific primers/DGGE approach is a new step toward a more complete understanding of functionally important groups of bacteria involved in biological treatment of waste-water.

An outbreak of subacute fasciolosis in Soay sheep: Ultrasonographic biochemical and histological studies

A naturally occurring outbreak of subacute fasciolosis in a group of 17 seven-month-old Soay ram lambs was studied following the sudden death of two sheep. In addition to standard biochemical investigations, ultrasound examination of the liver and cranial abdominal cavity was undertaken. There was a significant positive linear correlation between liver weight and ultrasonographic determination of liver size (R=0.72, P<0.05). Ultrasonographic examination of the liver revealed multiple hyperechoic dots in the parenchyma giving a granular appearance to the hepatic texture in three sheep corresponding to the most advanced histopathological changes as determined by the size of the abscesses and their relatively mature fibrous capsules, and areas of hepatic necrosis. No distension of the bile duct system was noted nor was the gall bladder imaged. While serum concentrations of albumin, globulin and certain liver enzymes assisted in the diagnosis of subacute fasciolosis in sheep, only glutamate dehydrogenase, and gammaglutamyl transferase remained elevated four weeks after triclabendazole treatment.

Fecal pollution in water from storm sewers and adjacent seashores in Natal, Rio Grande do Norte, Brazil

A study on the distribution patterns of enteropathogenic bacteria polluting the shoreline in Natal, Rio Grande do Norte, Brazil, was carried out based on 72 samples obtained from three storm sewers and adjoining beach locations, Praia do Meio (PM), Areia Preta (AP) and Ponta Negra (PN). From each location, 12 water samples were taken and analyzed for fecal coliforms (FC) and Escherichia coli. In AP, two (16.7%) of the seawater samples and five (41.7%) of the storm sewer samples yielded values above 1.1 x 107 FC/100 ml, whereas only one (8.3%) of the samples from PM reached this level. There was no correlation (p > 0.05) between rainfall indices and FC values. A total of 64 E. coli isolates were obtained: 37 from the storm sewer samples and 27 from the seawater samples. Of these isolates, four (O143, two O112ac, and O124) were enteroinvasive and two (O111 and O125) were enteropathogenic. Resistance to antibiotics and to heavy metals was also analyzed. Almost 36% of the E. coli strains isolated were resistant to more than one antibiotic. All strains were resistant to zinc and copper at the highest concentration tested (250 microg/ml), and several (23.4%) were resistant to mercury at 50 microg/ml. Our results agreed with previous reports that antibiotic resistance is commonly associated with heavy-metal resistance in pathogens.

Premonitory symptoms in migraine: an electronic diary study

BACKGROUND

Migraine is frequently associated with nonheadache symptoms before, during, and after the headache. Premonitory symptoms occurring before the attack have not been rigorously studied. Should these symptoms accurately predict headache, there are considerable implications for the pathophysiology and management of migraine.

METHODS

Electronic diaries were used in a 3-month multicenter study to record nonheadache symptoms before, during, and after migraine. The authors recruited subjects who reported nonheadache symptoms in at least two of three attacks that they believed predicted headache. Symptoms were entered in the diaries by patient initiation and through prompted entries at random times daily. Entries could not be altered retrospectively. Data recorded included nonheadache symptoms occurring during all three phases of the migraine, prediction of the attack from premonitory symptoms, general state of health, and action taken to prevent the headache.

RESULTS

One hundred twenty patients were recruited: 97 provided usable data. Patients correctly predicted migraine headaches from 72% of diary entries with premonitory symptoms. A range of cognitive and physical symptoms was reported at a similar rate through all three phases of the migraine. The most common premonitory symptoms were feeling tired and weary (72% of attacks with warning features), having difficulty concentrating (51%), and a stiff neck (50%). Subjects who functioned poorly in the premonitory phase were the most likely to correctly predict headache.

CONCLUSIONS

Using an electronic diary system, the authors show that migraineurs who report premonitory symptoms can accurately predict the full-blown headache.

Use of rpoB and 16S rRNA genes to analyse bacterial diversity of a tropical soil using PCR and DGGE

AIM

To evaluate the rpoB gene as a biomarker for PCR-DGGE microbial analyses using soil DNA from the Cerrado, Brazil.

METHODS

DNA extraction from soil was followed by Polymerase Chain Reaction (PCR) amplification of rpoB and 16S rRNA genes. PCR products were compared by Denaturing Gradient Gel Electrophoresis (DGGE) to compare gene/community profiles.

RESULTS

The rpoB DGGE profiles comprised fewer bands than the 16S rDNA profiles and were easier to delineate and therefore to analyse. Comparison of the community profiles revealed that the methods were complementary.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

The gene for the beta subunit of the RNA polymerase, rpoB, is a single copy gene unlike 16S rDNA. Multiple copies of 16S rRNA genes in bacterial genomes complicate diversity assessments made from DGGE profiles. Using the rpoB gene offers a better alternative to the commonly used 16S rRNA gene for microbial community analyses based on DGGE.

Novel bacterial diversity recovered from the rhizosphere of oilseed rape (Brassica napus) determined by the analysis of 16S ribosomal DNA

Soil was sampled to a distance of 2.5 mm beneath a root mat of oilseed rape (Brassica napus) in a model rhizosphere system. DNA was extracted and the 16S rDNA amplified, cloned and sequenced. Phylogenetic analysis of these sequences with those held on-line, revealed that 37% of the clones fell within the Holophaga /Acidobacterium phylum, 17% were within the proteobacteria, 14% of the clones were close relatives of Bacillus megaterium and 5% were related to Verrucomicrobium spinosum. An additional eleven clones (21%) could not be assigned to any known phylum and may represent novel bacterial lineages. This study highlights the diverse nature of rhizosphere soils and reinforces the role that molecular approaches play in unravelling such diversity.

Small is beautiful: comparative genomics with the pufferfish (Fugu rubripes)

As the Human Genome Project advances, it is clear that the emphasis will switch from accumulation of data to their interpretation. Comparative genomics provides a powerful way in which to analyse sequence data. Indeed, there is already a long list of 'model' organisms, which allow comparative analyses in a variety of ways. The very small vertebrate genome of the pufferfish provides a simple and economical way of comparing sequence data from mammals and fish, representing a large evolutionary divergence and so permitting the identification of essential elements that are still present in both species. These elements include genes and the associated machinery that controls their expression; elements that, in many cases, have survived the test of time.

The prevalence of eating disorders in thyroid disease: a pilot study

The aim of this study was to determine the prevalence of eating disorders and partial syndromes in women with thyroid disease. Female patients between the ages of 18 and 45 who attended a specialist thyroid clinic, in 1990, were asked to complete two self-report questionnaires (Bulimic Investigatory Test, Edinburgh, BITE and General Health Questionnaire, GHQ). High scoring patients were invited to attend for a research interview. The case notes of non-responders were examined. Seventy-three patients were entered into the study and 50 subjects returned their questionnaires (69%). Eleven patients scored highly on the BITE, nine of these patients also scoring highly on the GHQ, as did a further 12 patients. Ten patients were interviewed; of these, three patients (4%) met DSM111R criteria for bulimia nervosa and three patients met criteria for an eating disorder not otherwise specified. These results suggest that there is an increased prevalence of eating disorders in women thyroid patients.

Characterization of the pufferfish (Fugu) genome as a compact model vertebrate genome

Cloning and sequencing techniques now allow us to characterize genes directly instead of having to deduce their properties from their effects. This new genetics reaches its apotheosis in the plan to obtain the complete DNA sequence of the human genome, but this is far beyond the capacity of present sequencing methods. Small 'model' genomes, 'such as those of Escherichia coli (4.7 megabases (Mb) and yeast (14 Mb), or even those of Caenorhabditis elegans (100 Mb) and Drosophila (165 Mb), are better scaled to existing technology. The yeast genome will contain genes with functions common to all eukaryotic cells, and those of simple multicellular organisms may throw light on the genetic specification of more complex functions. However, vertebrates differ in their morphology and development, so the ideal model would be a vertebrate genome of minimum size and complexity but with maximum homology to the human genome. Here we report the characterization of the small genome (400 Mb) of the tetraodontoid fish, Fugu rubripes. A random sequencing approach supported by gene probing shows that the haploid genome contains 400 Mb of DNA, of which more that 90% is unique. This genome is 7.5 times smaller than the human genome and because it has a similar gene repertoire it is the best model genome for the discovery of human genes.

Pituitary adenylate cyclase activating polypeptide is a potent vasodilator in humans

The vasodilator effect of the novel peptide pituitary adenylate cyclase activating polypeptide (PACAP) was investigated in humans. Forearm blood flow was measured in six healthy men by venous occlusion plethysmography. Infusion of PACAP into the brachial artery at 0.01, 0.1, 1, 3, and 10 pmol/min produced a dose-related increase in forearm blood flow in the cannulated arm from 2.8 +/- 0.6 to 8.6 +/- 2.4 ml/100 ml/min at the highest dose (mean +/- SEM, p less than 0.05). In a subsequent experiment, where the highest dose of PACAP was repeated after a 36 min interval, there was no tachyphylaxis of the forearm blood flow response, with the forearm blood flow increasing by 129 +/- 9% during the first infusion and 128 +/- 31% during the second infusion (N.S.). In further experiments, microvascular blood flow was measured by a laser-Doppler flow probe to compare the effects of intradermally injected PACAP, vasoactive intestinal polypeptide (VIP), and calcitonin gene-related peptide (CGRP). When injected into the skin of normal volunteers at 10(-12) to 10(-11) mol/site, each peptide caused a rapid flare lasting 2-3 min, which became erythematous after 5 min. At 10(-12) mol/site, intradermally injected PACAP and VIP caused a maximum increase in skin blood flow at 15 min of 379 +/- 96 and 307 +/- 121% (% increase above basal +/- SEM), respectively, and these responses were not significantly affected by oral aspirin (600 mg) taken 1.5 h beforehand. The vasodilation induced by PACAP at 10(-12) mol/site lasted approximately 6 h, whereas the effect of the same dose of CGRP and VIP lasted less than 2 h. These data suggest that PACAP is a potent and long-lasting vasodilator in humans.