Impact of the zinc complexation of polytopic polyaza ligands on the interaction with double and single stranded DNA/RNA and antimicrobial activity.

Metal complexes have gained a huge interest in the biomedical research in the last decade because of the access to unexplored chemical space with regards to organic molecules and to present additional functionalities to act simultaneously as diagnostic and therapeutic agents. Herein, we evaluated the interaction of two polytopic polyaza ligands and their zinc complexes with DNA and RNA by UV thermal denaturation, fluorescence and circular dichroism spectroscopic assays. The zinc coordination was investigated by X-ray diffraction and afforded the structure of the binuclear zinc complex of PYPOD. Thermal denaturation of DNA and RNA and fluorimetry analysis revealed preferential binding of the zinc-PHENPOD complexes towards GC-containing DNA in contrast to the free ligands. On the other hand, PYPOD metal complexes, compared to the free ligand, stabilized AT-based DNA (B-form) better than AU-RNA (A-form). With regards to single stranded RNA, the binuclear complex of PHENPOD and the free ligand can efficiently identify polyadenylic acid (poly A) among other RNA sequences by circular dichroism spectroscopy. The antimicrobial activity in S. aureus and E. coli bacteria showed the highest activity for the free ligands and their trinuclear zinc complexes. This work can provide valuable insights into the impact of the nuclearity of polytopic polyaza ligands in the binding to DNA/RNA and the antimicrobial effect.

Alkaloids as Photosensitisers for the Inactivation of Bacteria.

Antimicrobial photodynamic therapy has emerged as a powerful approach to tackle microbial infections. Photodynamic therapy utilises a photosensitiser, light, and oxygen to generate singlet oxygen and/or reactive oxygen species in an irradiated tissue spot, which subsequently react with nearby biomolecules and destroy the cellular environment. Due to the possibility to irradiate in a very precise location, it can be used to eradicate bacteria, fungus, and parasites upon light activation of the photosensitiser. In this regard, natural products are low-cost molecules capable of being obtained in large quantities, and some of them can be used as photosensitisers. Alkaloids are the largest family among natural products and include molecules with a basic nature and aromatic rings. For this study, we collected the naturally occurring alkaloids used to treat microorganism infections using a photodynamic inactivation approach. We gathered their main photophysical properties (excitation/emission wavelengths, quantum yields, and oxygen quantum yield) which characterise the ability to efficiently photosensitise. In addition, we described the antibacterial activity of alkaloids upon irradiation and the mechanisms involved in the microorganism killing. This review will serve as a reference source to obtain the main information on alkaloids used in antimicrobial photodynamic therapy.

Optimising the in vitro and in vivo performance of oral cocrystal formulations via spray coating.

Engineering of pharmaceutical cocrystals is an advantageous alternative to salt formation for improving the aqueous solubility of hydrophobic drugs. Although, spray drying is a well-established scale-up technique in the production of cocrystals, several issues can arise such as sublimation or stickiness due to low glass transition temperatures of some organic molecules, making the process very challenging. Even though, fluidised bed spray coating has been successfully employed in the production of amorphous drug-coated particles, to the best of our knowledge, it has never been employed in the production of cocrystals. The feasibility of this technique was proven using three model cocrystals: sulfadimidine (SDM)/4-aminosalicylic acid (4ASA), sulfadimidine/nicotinic acid (NA) and ibuprofen (IBU)/ nicotinamide (NAM). Design of experiments were performed to understand the critical formulation and process parameters that determine the formation of either cocrystal or coamorphous systems for SDM/4ASA. The amount and type of binder played a key role in the overall solid state and in vitro performance characteristics of the cocrystals. The optimal balance between high loading efficiencies and high degree of crystallinity was achieved only when a binder: cocrystal weight ratio of 5:95 or 10:90 was used. The cocrystal coated beads showed an improved in vitro-in vivo performance characterised by: (i) no tendency to aggregate in aqueous media compared to spray dried formulations, (ii) enhanced in vitro activity (1.8-fold greater) against S. aureus, (iii) larger oral absorption and bioavailability (2.2-fold higher Cmax), (iv) greater flow properties and (v) improved chemical stability than cocrystals produced by other methods derived from the morphology and solid nature of the starter cores.

Modelling and shadowgraph imaging of cocrystal dissolution and assessment of in vitro antimicrobial activity for sulfadimidine/4-aminosalicylic acid cocrystals.

PURPOSE: The aim of this work was to evaluate the influence of crystal habit on the dissolution and in vitro antibacterial and anitiprotozoal activity of sulfadimidine:4-aminosalicylic acid cocrystals. METHODS: Cocrystals were produced via milling or solvent mediated processes. In vitro dissolution was carried out in the flow-through apparatus, with shadowgraph imaging and mechanistic mathematical models used to observe and simulate particle dissolution. In vitro activity was tested using agar diffusion assays. RESULTS: Cocrystallisation via milling produced small polyhedral crystals with antimicrobial activity significantly higher than sulfadimidine alone, consistent with a fast dissolution rate which was matched only by cocrystals which were milled following solvent evaporation. Cocrystallisation by solvent evaporation (ethanol, acetone) or spray drying produced flattened, plate-like or quasi-spherical cocrystals, respectively, with more hydrophobic surfaces and greater tendency to form aggregates in aqueous media, limiting both the dissolution rate and in vitro activity. Deviation from predicted dissolution profiles was attributable to aggregation behaviour, supported by observations from shadowgraph imaging. CONCLUSIONS: Aggregation behaviour during dissolution of cocrystals with different habits affected the dissolution rate, consistent with in vitro activity. Combining mechanistic models with shadowgraph imaging is a valuable approach for dissolution process analysis.

Prevalencia del virus de la hepatitis E (VHE) y factores de riesgo en trabajadores de explotaciones porcinas y donantes voluntarios / Prevalence of hepatitis E virus (HEV) and risk factors in pig workers and blood donors

Introducción El virus de la hepatitis E (VHE) es el principal agente causal de hepatitis no-A no-B de transmisión entérica. El incremento de casos autóctonos y la elevada prevalencia detectada en el ganado porcino sugieren la posibilidad de la existencia de un reservorio animal. El objetivo de este trabajo es determinar la presencia del VHE, de anticuerpos anti-VHE de clase IgG e IgM así como los factores de riesgo en individuos sanos con y sin exposición a ganado porcino. Métodos Se incluyeron un total de 212 individuos, 113 con exposición y 99 sin exposición a ganado porcino. En todos los sueros se determinó la presencia del ARN-VHE y anticuerpos anti-VHE IgG e IgM. Las muestras positivas para anti-VHE IgM e IgG se confirmaron por inmunoblot. Resultados El ARN-VHE y los anticuerpos anti-VHE IgM no se detectaron en ninguna muestra. De las 212 personas analizadas, 25 (11,8%) presentaron anti-VHE IgG, siendo 21 (18,6%) expuestos y 4 (4%) no expuestos a ganado porcino (p=0,004); 19 personas de todos los analizados (12,8%) habían viajado al extranjero en el último año (p=0,507). En cuanto a los datos de los 25 individuos que presentaban anti-VHE IgG, ninguno de ellos había consumido marisco crudo (p=0,999); 23 (12,6%) consumieron verduras crudas (p=0,387); y 12 (30%) consumían habitualmente agua no tratada (p=0,008).Conclusiones Los datos obtenidos en este estudio sugieren que la infección por el VHE puede tratarse como una enfermedad ocupacional en trabajadores del sector porcino y que deberían tomarse las medidas higiénico-sanitarias correspondientes en este grupo para disminuir la exposición al VHE (AU)

Introduction Hepatitis E virus (HEV) is the main causative agent of enterically transmitted non-A non-B hepatitis with a self-limiting clinical presentation in humans. The increasing number of non-immigrant cases of hepatitis E and the high prevalence detected in pigs suggested that this species is a reservoir. Several studies have been published describing differences in the prevalence of anti-HEV antibodies between people exposed and not exposed to pigs, but the risk factors for the acquisition of the virus have not been well studied. The aim of this work was to study the prevalence of hepatitis E virus (HEV), IgG and IgM antibodies anti-HEV and the risk factors for the acquisition of this virus in a populations exposed and unexposed to pigs.MethodsSera from 212 people were tested for the presence of RNA-HEV, IgG and IgM antibodies anti-HEV. Positive results obtained using ELISA assays were confirmed by western-blot.ResultsRNA-HEV and IgM anti-VHE were not detected in any of the individuals. Twenty-five samples (11.8%) showed IgG anti-HEV, 21 (18.6%) persons in contact with pigs and 4 (4%) unexposed individuals (P=0.004); 19 (12.8%) had travelled out of Spain in the last year (P=0.507). None of the 25 seropositive people had consumed raw shellfish (P=0.999), whereas 23 (12.6%) had consumed raw vegetables (P=0.387) and 12 (30%) usually drank untreated water (P=0.008).ConclusionThese data support that HEV infection should be treated as an occupational disease illness in pig workers. Therefore, systematic application of hygiene measures in this group is highly recommended to avoid exposure to this virus (AU)

[Prevalence of hepatitis E virus (HEV) and risk factors in pig workers and blood donors]. / Prevalencia del virus de la hepatitis E (VHE) y factores de riesgo en trabajadores de explotaciones porcinas y donantes voluntarios.

INTRODUCTION: Hepatitis E virus (HEV) is the main causative agent of enterically transmitted non-A non-B hepatitis with a self-limiting clinical presentation in humans. The increasing number of non-immigrant cases of hepatitis E and the high prevalence detected in pigs suggested that this species is a reservoir. Several studies have been published describing differences in the prevalence of anti-HEV antibodies between people exposed and not exposed to pigs, but the risk factors for the acquisition of the virus have not been well studied. The aim of this work was to study the prevalence of hepatitis E virus (HEV), IgG and IgM antibodies anti-HEV and the risk factors for the acquisition of this virus in a populations exposed and unexposed to pigs. METHODS: Sera from 212 people were tested for the presence of RNA-HEV, IgG and IgM antibodies anti-HEV. Positive results obtained using ELISA assays were confirmed by western-blot. RESULTS: RNA-HEV and IgM anti-VHE were not detected in any of the individuals. Twenty-five samples (11.8%) showed IgG anti-HEV, 21 (18.6%) persons in contact with pigs and 4 (4%) unexposed individuals (P=0.004); 19 (12.8%) had travelled out of Spain in the last year (P=0.507). None of the 25 seropositive people had consumed raw shellfish (P=0.999), whereas 23 (12.6%) had consumed raw vegetables (P=0.387) and 12 (30%) usually drank untreated water (P=0.008). CONCLUSION: These data support that HEV infection should be treated as an occupational disease illness in pig workers. Therefore, systematic application of hygiene measures in this group is highly recommended to avoid exposure to this virus.

Occupational exposure to hepatitis E virus (HEV) in swine workers.

The aim of this work was to study the prevalence of hepatitis E virus (HEV) and the risk factors for the acquisition of the virus in a population in contact with swine and unexposed to swine. A total of 198 individuals, 97 unexposed (49%) and 101 exposed (51%) to swine, were tested for the presence of HEV infection. The prevalence of anti-HEV IgG in the exposed group was 18.8% versus 4.1% in the unexposed to swine group. People exposed to swine were observed to be 5.4 times (P = 0.03) at risk of having anti-HEV IgG. Ten (52.6%) of the IgG-positive individuals showed two concomitant risk factors: untreated water consumption and exposure to swine. These data support that HEV infection should be treated as a vocational illness in swine workers. Therefore, systematic application of hygiene measures in this collective is highly recommended to avoid the exposition to this virus.

Autochthonous hepatitis E infection in a slaughterhouse worker.

We report the first hepatitis E infection case detected in a slaughterhouse worker. The identified strain belonged to genotype 3, subtype 3f. Partial sequence analysis of the strain isolated from his serum showed a percentage of nucleotide homology ranging from 83.4% up to 97.3% compared with European human and swine strains, respectively. These findings point strongly to hepatitis E virus as a vocationally acquired illness by means of the manipulation of infected organs from pigs.

Prevalence and genetic characterization of hepatitis E virus in paired samples of feces and serum from naturally infected pigs.

This study describes the distribution of Hepatitis E virus (HEV) in a naturally infected swine population and the genetic relatedness of HEV strains on swine farms in Spain. Of fecal and serum samples collected from 131 pigs and manure-ditch samples collected from 17 farms, HEV was detected in 16%, 14%, and 59%, respectively, for an overall prevalence rate of 23%. The maximum prevalence rates for feces and serum were in pigs 5 to 12 wk old. A high prevalence of the virus in feces (18%) was observed in sows. Gene sequencing was performed on 6 strains from feces, serum, and manure ditch: the nucleotide identities varied from 81.5% to 99% when compared with those of other strains of genotype 3 isolated from swine. This is the first study in Europe to show the variation in virus distribution by age in feces and serum in a naturally infected swine population.

New culture media for the isolation of Streptococcus mutans and Lactobacillus in the saliva of head- and neck-irradiated patients.

UNLABELLED: The reduction in salivary flow in patients subjected to head and neck irradiation induces changes in the oral microflora and increases the risk of oral mucosal infections. The frequent presence of fungi, particularly Candida, in the oral environment of these patients complicates identification of the most important cariogenic bacteria with the commercial CRT Bacteria (Ivoclar Vivadent) culture media. Such identification is important for the application of chemical measures to control cariogenic bacteria in these patients, since it has been shown that simple fluoride application is unable to control caries in this population. OBJECTIVE: The aim of this study was to obtain a simple medium that inhibits Candida spp. growth and allows the specific growth of Streptococcus mutans and Lactobacillus spp. Thus, reliable counts of cariogenic species can be achieved. MATERIALS AND METHODS: Stimulated saliva samples from 30 head- and neck-radiotherapy patients were seeded in commercial CRT Bacteria culture medium and in two different media designed by our group: mitis salivarius bacitracin agar (MSBA), containing 5% potassium tellurite and fluconazole 64 microg/ml (MSBTPF) for the isolation of Streptococcus; and Man, Rogosa and Sharpe (MRS) agar, containing bacitracin 0.2 U/ml and fluconazole 32 microg/ml (MRSBF) for the isolation of Lactobacillus spp. RESULTS: Candida growth was inhibited 100% in the media developed in this study. In all the samples seeded, growing of colonies in MRSBF was identified as Lactobacillus, while in CRT Bacteria for Lactobacillus spp. this species was only isolated in 48.1% of the samples. S. mutans was identified in 71.4% of the colonies that grown in MSBTPF medium, while in CRT Bacteria for S. mutans, this species was only identified in 35% of the colonies obtained. CONCLUSION: The culture medium developed in the present study was able to inhibit the 100% of Candida spp. growth. These new media permit reliable counts of cariogenic bacteria in irradiated patients.

Detection of hepatitis E virus shedding in feces of pigs at different stages of production using reverse transcription-polymerase chain reaction.

The aim of this study was to determine at which production stages hepatitis E virus (HEV) is shed by the highest number of pigs and to estimate the relative risk associated with each stage. For this purpose, 146 fecal samples of pigs from 21 farms were studied. In addition, 1 sample from the manure ditch and another sample of drinking water, collected directly from the trough located in the pen, were taken from 16 farms. HEV RNA was detected in fecal samples from 34 pigs (23.29%). The production stages in which most pigs excreted HEV were weaners (41.7%) and pigs in the first month of feeding (60%). The results of the statistical analysis showed that the principal significant risk stage in HEV shedding was the first month of feeding (odds ratio [OR] 19.5, 95% CI 3.59-106.07, P = 0.001) followed by the weaners stage (OR 9.3, 95% CI .78-48.42, P = 0.008). In 8 out of 16 farms tested (50%) HEV RNA was detected in raw manure and in the water trough of only 1. Detection of HEV in manure ditches raises the concern of how to deal with manure of swine origin, because it is used as soil fertilizer.