Suspect and non-target screening: the last frontier in environmental analysis

Suspect and non-target screening (SNTS) techniques are arising as new analytical strategies useful to disentangle the environmental occurrence of the thousands of exogenous chemicals present in our ecosystems. The unbiased discovery of the wide number of substances present over environmental analysis needs to find a consensus with powerful technical and computational requirements, as well as with the time-consuming unequivocal identification of discovered analytes. Within these boundaries, the potential applications of SNTS include the studies of environmental pollution in aquatic, atmospheric, solid and biological samples, the assessment of new compounds, transformation products and metabolites, contaminant prioritization, bioremediation or soil/water treatment evaluation, and retrospective data analysis, among many others. In this review, we evaluate the state of the art of SNTS techniques going over the normalized workflow from sampling and sample treatment to instrumental analysis, data processing and a brief review of the more recent applications of SNTS in environmental occurrence and exposure to xenobiotics. The main issues related to harmonization and knowledge gaps are critically evaluated and the challenges of their implementation are assessed in order to ensure a proper use of these promising techniques in the near future.

Adverse events using shorter MDR-TB regimens: outcomes from Port Moresby, Papua New Guinea

Evidence increasingly indicates that standardised, shorter regimens (SR) for multidrug-resistant TB (MDR-TB) is effective in treating this global disease, but there is little published data on associated adverse events. We report outcomes from a cohort treated with the SR in Port Moresby, Papua New Guinea (PNG). Among 26 patients treated with a TB SR from September 2017 to September 2018, 10 (39%) were successful treatments, 12 (46%) were failures, 2 died, and 2 were lost to follow-up. Of those whose treatment failed, most (n = 10) changed their regimen due to adverse events, including seven from ototoxicity, suggesting this SR may not be suited to all patients in PNG and similar settings.

Molecular detection and identification of piroplasms (Babesia spp. and Theileria spp.) and Anaplasma phagocytophilum in questing ticks from northwest Spain

Anaplasma phagocytophilum and some piroplasm species are pathogens mainly transmitted by Ixodes ricinus. Considering that this tick species is predominant in north-western Spain, individual specimens (652 nymphs, 202 females and 202 males) and 23 larval pools were processed to determine the prevalence of these pathogens in questing I. ricinus from that region. Additionally, Dermacentor marginatus, Dermacentor reticulatus, Ixodes frontalis and Ixodes acuminatus were individually analysed. The groESL operon as well as the 16S rRNA and msp2 genes of Anaplasma were analysed. Similarly, piroplasms were identified at the 18S rRNA gene and the ITS1 of Babesia spp. and Theileria spp. Babesia venatorum (1.5%), A. phagocytophilum (0.7%), Babesia microti (0.3%) and Theileria sp. OT3 (0.2%) were detected in I. ricinus. A single I. frontalis (8.3%) tested positive to A. phagocytophilum. Although a low percentage of I. ricinus were infected with A. phagocytophilum and piroplasms, a potentially human pathogenic variant of A. phagocytophilum was detected, and both Babesia species found were zoonotic. Since the vector of Theileria sp. OT3 remains unknown, further investigations are needed to unravel the role of I. ricinus in the transmission of this piroplasm.

Thrombotic thrombocytopenia following ChAdOx1 nCov-19 vaccination

Serious thromboembolic events with concurrent thrombocytopenia, sometimes accompanied by bleeding, have occurred very rarely following administration of the ChAdOx1 nCoV-19 vaccine. We report the case of a 59-year-old male with an unremarkable medical history who presented to the emergency department with increasing breathlessness five days after receiving the first dose of ChAdOx1 nCov-19. The patient's blood results showed mild thrombocytopenia and a very high D-dimer, and a pulmonary embolism was confirmed through a CT pulmonary angiogram, which led to a provisional diagnosis of vaccine-induced immune thrombotic thrombocytopenia. The condition was then treated with immunoglobulin and intravenous argatroban in line with the guidance from the Expert Haematology Panel focussed on Vaccine-induced Thrombosis and Thrombocytopenia before conversion to apixaban.

Migration of photoinitiators, phthalates and plasticizers from paper and cardboard materials into different simulants and foodstuffs

The migration of photoinitiators, phthalates and plasticizers from two paper and cardboard materials into food simulants (50% and 95% EtOH and Tenax) and foodstuffs (rice, cereals and milk powder) was studied. In the case of liquid simulants migration was observed to reach the equilibrium after 60 min and depended on the material type and the physicochemical parameters of the migrants, whereas the temperature (room temperature and 60 °C) did not show significant effects. The study of migration of the compounds from a baking paper to Tenax at high temperatures (150 and 250 °C) evidenced an increment of migration when increasing temperature, except for the most volatile analytes. Finally, the migration to foodstuffs was studied using fully validated analytical protocols. Overall, the comparison of the migration rates demonstrated that Tenax was adequate for the simulation of the migration to rice and cereals, but underestimated the migration to infant milk powder, for which 95% EtOH resulted a more suitable simulant.

Overexpression of the third H-NS paralogue H-NS2 compensates fitness loss in hns mutants of the enteroaggregative Escherichia coli strain 042

Members of the H-NS protein family play a role both in the chromosome architecture and in the regulation of gene expression in bacteria. The genomes of the enterobacteria encode an H-NS paralogue, the StpA protein. StpA displays specific regulatory properties and provides a molecular backup for H-NS. Some enterobacteria also encode third H-NS paralogues. This is the case of the enteroaggregative E. coli (EAEC) strain 042, which encodes the hns, stpA and hns2 genes. We provide in this paper novel information about the role of the H-NS2 protein in strain 042. A C > T transition in the hns2 promoter leading to increased H-NS2 expression is readily selected in hns mutants. Increased H-NS2 expression partially compensates for H-NS loss. H-NS2 levels are critical for the strain 042 fitness. Under some circumstances, high H-NS2 expression levels dictated by the mutant hns2 promoter can be deleterious. The selection of T > C revertants or of clones harboring insertional inactivations of the hns2 gene can then occur. Temperature also plays a relevant role in the H-NS2 regulatory activity. At 37 °C, H-NS2 targets a subset of the H-NS repressed genes contributing to their silencing. When temperature drops to 25 °C, the repressory ability of H-NS2 is significantly reduced. At low temperature, H-NS plays the main repressory role.

Focused ultrasound-based extraction for target analysis and suspect screening of organic xenobiotics in fish muscle

The development of multitarget and/or suspect screening methods for the analysis of xenobiotics in fish samples is compulsory due to the lack of works in the literature where a deep evaluation of the variables affecting extraction and clean-up steps is performed. The aim of the present work was to optimize and validate a multitarget (180 compounds) method for the analysis of priority and emerging xenobiotics in fish muscle using focused ultrasound-assisted solid-liquid extraction. From the different extraction solvents studied, a single extraction in cold acetonitrile rendered the best consensus results in terms of absolute recoveries and the number of target compounds extracted. Matrix effect was minimized using commercially available Captiva ND-Lipid filters, which provided clean extracts and satisfactory repeatability compared to other approaches. Absolute recoveries were corrected using matrix-matched calibration and apparent recoveries in the 43%-105%, 73%-131% and 78%-128% ranges were obtained at low (20 ng g^-1), medium (100 ng g^-1), and high (200 ng g^-1) spiking levels, respectively. A 60% of the xenobiotics showed limits of identification lower than 20 ng g^-1. The developed method was successfully applied to the quantification and suspect screening of samples bought in a local market (hake, gilt-head bream, sea bass and prawn) and fished (thicklip grey mullet) at the Urdaibai estuary (north of Spain). Food additives, antiparasitic drugs and PFOS were quantified at ng g^-1 level. Moreover, the targeted method was extended to the suspect screening, revealing the presence of plastic related products (caprolactam, phthalates, polyethylenglycols), pharmaceutical products (albendazole, mebendazole, valpromide) and pesticides or insect repellents (icaridin, myristyl sulfate, nootkatone). Therefore, FUSLE in cold acetonitrile combined with Captiva ND-Lipid filters and liquid chromatography tandem high-resolution mass spectrometry (LC-q-Orbitrap) were successfully applied to both multitarget quantitative analysis and suspect screening of approx. 17,800 compounds.

Application of the Sea Urchin Embryo Test in Toxicity Evaluation and Effect-Directed Analysis of Wastewater Treatment Plant Effluents

Sea urchin embryo assay was used to assess general toxicity at four wastewater treatment plant effluents of Biscay (Gorliz, Mungia, Gernika, and Galindo), and within the tested range, all the extracts showed embryo growth inhibition and skeleton malformation activities with EC₅₀ values, in relative enrichment factor units, between 1.1-16.8 and 1.1-8.8, respectively. To identify the causative compounds, effect-directed analysis was successfully applied for the first time using a sea urchin embryo test to the secondary treatment of the Galindo effluent. To this end, two subsequent fractionation steps were performed using C18 (21 fractions) and aminopropyl columns (15 fractions). By this fractionation, the number of features detected by LC-HRMS in the raw sample was drastically reduced from 1500 to 9, and among them, two pesticides (mexacarbate, 17 ng/L, and fenpropidin, 23 ng/L), two antidepressants (amitriptyline, 304 ng/L, and paroxetine, 26 ng/L), and two anthelmintic agents (mebendazole, 65 ng/L, and albendazole, 48 ng/L) could be identified in the two toxic fractions. The artificial mixture of the identified six compounds could explain 79% of the observed effect, with albendazole and paroxetine as the predominant contributors (49% and 49%, respectively) affecting the sea urchin embryogenesis activity.

Temporal and spatial spread of Hypoderma actaeon infection in roe deer from peninsular Spain determined by an indirect enzyme-linked immunosorbent assay

The host switching of Hypoderma actaeon (Diptera: Oestridae), a specific parasite of red deer (Cervus elaphus), towards roe deer (Capreolus capreolus) has been recently reported in Spain. To provide information about the temporal and spatial spreading of H. actaeon infection in roe deer, 244 serum samples from animals hunted in Spain between 2013 and 2018 were analysed by an indirect enzyme-linked immunosorbent assay. The overall seropositivity was 13.9%. Seropositivity was higher in continental (27.7%) and mountainous (12%) areas from central Spain, followed by southern-Mediterranean (11.2%) and northern-oceanic regions (3.5%). Differences were significant between central-continental and northern-oceanic regions (P = 0.003). No differences were found according to the sex and age of roe deer (P > 0.05). In 2013, all seropositive animals were concentrated in two distant areas in central and southern Spain, suggesting that the host switch could have occurred independently in both regions. Changes in the pattern of distribution of red deer and roe deer could have favoured the spreading of this myiasis towards roe deer, indicating that roe deer may become infested by H. actaeon in areas where both cervids coexist at high densities.

Short-term stability assessment for the analysis of emerging contaminants in seawater

This paper describes the stability study performed in seawater and seawater extracts (spiked at ~ 200 ng/L) for 23 emerging contaminants. Four different alternatives were tested at six different times (0, 3, 10, 17, 24 and 31 days): (i) seawater at 4 °C, (ii) mixed-mode solid-phase extraction cartridge (Bond Elute Plexa and Strata X-AW) stored at - 20 °C, (iii) polyethersulfone hollow fibre stored at - 20 °C and (iv) methanol extracts once the samples were extracted from PES hollow fibre and stored at - 20 °C. Moreover, the integrity of the supporting polymeric phases was studied by Raman, optical microscopy, differential scanning calorimetric and thermogravimetric analysis. As may be expected, seawater samples showed the lowest stability (losses between 21 and 99%) while methanol extract provides stable results (losses < 30%) over the tested period. In the case of solid-phase cartridges, the stability profile showed an average loss of 7% while, in polyethersulfone hollow fibres, losses up to 58% were observed. Finally, we were able to relate the lower efficiency of polyethersulfone fibres with the wettability of this material based on the thermogravimetric analysis.

Association of Ureaplasma diversum with reproductive disease in cattle

Aims: To examine the association between the detection of Ureaplasma diversum in vaginal swabs from dairy cows in north western Spain with the diagnosis of granular vulvovaginitis (GVV) and reproductive performance, and the association with subclinical endometritis (SE) in slaughterhouse material. The presence of this microorganism in cases of abortion was also investigated. Methods: From 106 dairy farms in the province of Lugo, 40 herds were randomly selected. Vaginal swabs were obtained from 10 randomly selected cows per farm, then pooled for analysis to detect the presence of U. diversum by quantitative real-time PCR (qPCR). In five of these herds samples from the 10 animals were individually tested for U. diversum, and the presence of GVV lesions and their reproductive efficiency (number of inseminations to achieve pregnancy over two subsequent pregnancies) were determined. Vaginal swabs from uteri of cattle obtained at a slaughterhouse (n = 100) were tested for U. diversum and the presence of SE, defined as >5% polymorphonuclear cells in cytobrush smears, was determined. Sixteen farms with abortion problems submitted samples for culture and PCR testing including for U. diversum. Results: Of the 40 herds, 39 (98%) tested positive for U. diversum. On the five farms, 25/50 (50%) cows tested positive for U. diversum, and more cows with GGV-lesions (16/25; 64%) tested positive than cows without lesions (9/25; 36%) (p = 0.047). There were more cows with poor reproductive efficacy that tested positive (8/11; 57%) than tested negative (3/17; 18%) for U. diversum (p = 0.029). Of the 100 uteri, five tested positive for U. diversum and there were more uteri with SE that tested positive (3/19; 16%) than uteri without SE (2/81; 2%) (p = 0.036). U. diversum was also diagnosed in 4/16 farms with abortion problems and liver appeared to be the best tissue for detecting U. diversum DNA in the fetuses analysed. Conclusions and Clinical Relevance: Infection with U. diversum was present in most of herds investigated and it was statistically associated with GVV, SE and poor reproductive performance. It was also detected in abortions and the liver may also be an additional tissue to be considered in the diagnosis of U. diversum abortion by PCR. The possible association with different diseases in the same area suggests that different presentations should be considered when studying the implications of U. diversum on the reproductive diseases of cattle.

In vitro toxicity testing in hemocytes of the marine mussel Mytilus galloprovincialis (L.) to uncover mechanisms of action of the water accommodated fraction (WAF) of a naphthenic North Sea crude oil without and with dispersant

Dispersants used in oil spills could result toxic to marine organisms and could influence the toxicity of oil compounds. The aim of this work was to uncover the mechanisms of action of the water accommodated fraction (WAF) of a naphthenic North Sea crude oil produced at 10, 15 and 20 °C without and with the dispersant Finasol OSR52 (WAF and WAFD, respectively) using hemocytes of the marine mussel Mytilus galloprovincialis. Primary cultures of hemocytes were exposed in glass-coated microplates to different WAF or WAFD dilutions (0.25, 2.5, 25, 50 and 100%) and to the dispersant alone at the same concentrations present in the WAFD dilutions (1.25, 12.5, 125, 250 and 500 mg/L). Of the two in vitro approaches tested, the second one was selected which involved exposure of hemocytes for 4 h to unfiltered WAF, WAFD and dispersant dilutions without cell culture media. WAF decreased hemocytes viability only at the highest dilution whereas WAFD and the dispersant alone were cytotoxic at the three highest concentrations. Temperature of production of WAF, WAFD and dispersant did not influence their cytotoxicity to hemocytes. WAF increased ROS production and MXR transport activity in hemocytes. Exposure to WAFD and dispersant increased ROS production, provoked plasma membrane and actin cytoskeleton disruption and decreased phagocytic activity. In conclusion, the dispersant tested was toxic to mussel hemocytes and it greatly increased the toxicity of WAFD. The present data could be useful for the environmental risk assessment of oil spills and their remediation strategies in the marine environment.

Role of age and comorbidities in mortality of patients with infective endocarditis

PURPOSE

The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.

METHODS

Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.

RESULTS

A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32-3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39-1.88),and non-performed surgery (HR:1.64;95% CI:11.16-1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality.

CONCLUSION

There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group.

Amitriptyline at an Environmentally Relevant Concentration Alters the Profile of Metabolites Beyond Monoamines in Gilt-Head Bream

The antidepressant amitriptyline is a widely used selective serotonin reuptake inhibitor that is found in the aquatic environment. The present study investigates alterations in the brain and the liver metabolome of gilt-head bream (Sparus aurata) after exposure at an environmentally relevant concentration (0.2 µg/L) of amitriptyline for 7 d. Analysis of variance-simultaneous component analysis is used to identify metabolites that distinguish exposed from control animals. Overall, alterations in lipid metabolism suggest the occurrence of oxidative stress in both the brain and the liver-a common adverse effect of xenobiotics. However, alterations in the amino acid arginine are also observed. These are likely related to the nitric oxide system that is known to be associated with the mechanism of action of antidepressants. In addition, changes in asparagine and methionine levels in the brain and pantothenate, uric acid, and formylisoglutamine/N-formimino-L-glutamate levels in the liver could indicate variation of amino acid metabolism in both tissues; and the perturbation of glutamate in the liver implies that the energy metabolism is also affected. These results reveal that environmentally relevant concentrations of amitriptyline perturb a fraction of the metabolome that is not typically associated with antidepressant exposure in fish. Environ Toxicol Chem 2019;00:1-13. © 2019 SETAC.

Occurrence of emerging pollutants in estuaries of the Basque Country: Analysis of sources and distribution, and assessment of the environmental risk

In this study, the spatial and temporal-distribution of 41-multiclass organic compounds were assessed in three estuaries of the Basque Country, from winter 2016 to winter 2017 by grab (active) sampling methods and an extra campaign combining both, grab and passive sampling methods. Wastewater treatment plant (WWTP) effluents were also evaluated to assess their impact on the estuaries. Moreover, the physicochemical features (phosphate and nitrate concentrations, pH, etc.) of each site were measured and included in the statistical analysis. Anti-inflammatory drugs (diclofenac and acetaminophen), hypertensive drugs (irbesartan and valsartan), a stimulant (caffeine), an artificial sweetener (acesulfame) and a corrosion inhibitor (2-hydroxybenzothiazole) were the most ubiquitous compounds. Due to the stratification of the waters in the estuary of Bilbao two independent sources were identified: WWTP and harbour activities. In the case of Gernika and Plentzia, both are estuaries with a high tidal dilution, and the main sources were localized in the effluents of the WWTPs. In addition to this, the use of POCIS provides an efficient way to monitor emerging pollutants over a relatively long sampling period. Finally, risk quotient (RQ) values of each contaminant were estimated from the maximum values determined at each estuary and WWTP effluent for acute and chronic effects. In the case of acute toxicity the highest RQ values (»1) were obtained for the angiotensin II receptor blockers (telmisartan, eprosartan, etc.), diuron and diclofenac. In the case of the chronic toxicity the highest RQ values (»1) were estimated for caffeine, diclofenac, bezafibrate and sulfadiazine.

Multiresidue analytical method for the determination of 41 multiclass organic pollutants in mussel and fish tissues and biofluids by liquid chromatography coupled to tandem mass spectrometry

In this work, the full optimisation and validation procedure to analyse a wide set of emerging organic contaminants in biotissues (mussel and fish muscle, liver, gills and brain) and biofluids (fish plasma and bile) is described. The target families include artificial sweeteners, industrial products, hormones, pharmaceutical and personal care products, pesticides and phytoestrogens. Different clean-up strategies (hydrophilic-lipophilic-balanced (HLB) solid-phase extraction, Florisil solid-phase extraction and liquid-liquid extraction followed by HLB solid-phase extraction and microextraction based on polyethersulfone polymer) were evaluated for the clean-up of focused ultrasonic solid-liquid extraction (FUSLE) extracts before the analysis by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). The methods afforded satisfactory apparent recovery values (71-126%) using isotopically labelled analytes and matrix-matched calibration approach, regardless of the matrix. Method detection limits in the range of 4-48 ng/g and 0.3-111 ng/L were obtained for biotissues and biofluids, respectively. The developed method was applied to determine the uptake and tissue distribution in juvenile gilt-head bream (Sparus aurata) during 7 days in seawater, and unexpectedly, perfluoro-1-butanesulfonate tended to accumulate in liver and, to a lesser extent, in muscle and gills. Furthermore, real mussel samples collected in the Basque coast were also analysed and the presence of the highly consumed valsartan (7 ng/g) and telmisartan (6.8 ng/g) compounds in bivalves is reported for the first time here. Graphical abstract ᅟ.

Non-targeted metabolomics reveals alterations in liver and plasma of gilt-head bream exposed to oxybenzone

The extensive use of the organic UV filter oxybenzone has led to its ubiquitous occurrence in the aquatic environment, causing an ecotoxicological risk to biota. Although some studies reported adverse effects, such as reproductive toxicity, further research needs to be done in order to assess its molecular effects and mechanism of action. Therefore, in the present work, we investigated metabolic perturbations in juvenile gilt-head bream (Sparus aurata) exposed over 14 days via the water to oxybenzone (50 mg/L). The non-targeted analysis of brain, liver and plasma extracts was performed by means of UHPLC-qOrbitrap MS in positive and negative modes with both C18 and HILIC separation. Although there was no mortality or alterations in general physiological parameters during the experiment, and the metabolic profile of brain was not affected, the results of this study showed that oxybenzone could perturb both liver and plasma metabolome. The pathway enrichment suggested that different pathways in lipid metabolism (fatty acid elongation, α-linolenic acid metabolism, biosynthesis of unsaturated fatty acids and fatty acid metabolism) were significantly altered, as well as metabolites involved in phenylalanine and tyrosine metabolism. Overall, these changes are signs of possible oxidative stress and energy metabolism modification. Therefore, this research indicates that oxybenzone has adverse effects beyond the commonly studied hormonal activity, and demonstrates the sensitivity of metabolomics to assess molecular-level effects of emerging contaminants.

Study of bioconcentration of oxybenzone in gilt-head bream and characterization of its by-products

The widespread occurrence of UV filters such as oxybenzone (OXY) in the aquatic ecosystems has raised social and scientific concern due to their high bioaccumulation potential and possible adverse effects in organisms. Within this context, the aim of the present work was to study the uptake, distribution, metabolization and elimination of OXY in different tissues (liver, gill and muscle) and biofluids (bile and plasma) of gilt-head bream (Sparus aurata) in a controlled seawater ecosystem (50 ng/mL OXY) within a 14-day exposure. The highest OXY concentrations in all the tissue/biofluids were found at the end of the experiment. The highest OXY levels were found in bile (1.8-17 μg/mL). In the case of liver, the concentrations found (9-160 ng/g) were lower than those expected for a lipidic matrix, which could be explained by a high OXY metabolization. Up to 20 Phase I and Phase II by-products of OXY were annotated by means of liquid chromatography-high resolution mass spectrometry, of which 12 were reported for the first time. In addition to OXY, its by-products might also cause adverse effects and their biomonitoring is advisable in order to fully characterize OXY exposure.

Molecular characterisation and risk factor analysis of Cryptosporidium spp. in calves from Italy

To provide up-to-date information on the occurrence of Cryptosporidium in pre-weaned calves from Sardinia (Italy), the species implicated and their zoonotic potential, 147 faecal samples from 22 cattle herds were microscopically examined for Cryptosporidium oocysts; positive isolates were molecularly characterised. A questionnaire was developed to identify risk factors for Cryptosporidium infection. Overall, the percentage of positive calves and farms was 38.8 and 68.2%, respectively. The SSU rRNA-based PCR identified two Cryptosporidium species, Cryptosporidium parvum (95.8%) and C. bovis (4.2%). Sequence analyses of the glycoprotein (gp60) gene revealed that all C. parvum isolates belonged to the subtype family IIa (IIaA15G2R1 and IIaA16G3R1), with the exception of three isolates that belonged to the subtype family IId (IIdA20G1b and IIdA20). Mixed logistic regression results indicated that calves aged 15-21 days were more likely to be Cryptosporidium-positive. The risk of being positive was also significantly higher in herds from Central Sardinia and in farms using non-slatted flooring. In addition, the application of disinfectants and milk replacers was significantly associated with higher Cryptosporidium prevalence. In contrast, the risk of being positive was significantly reduced in halofuginone-treated calves. Our results reveal that a significant percentage of suckling calves are carriers of zoonotic subtypes of C. parvum. Thus, both healthy and diarrhoeic calves younger than 1 month may represent a risk for the transmission of cryptosporidiosis in humans and animals.

Evolution of Bacterial Global Modulators: Role of a Novel H-NS Paralogue in the Enteroaggregative Escherichia coli Strain 042

Bacterial genomes sometimes contain genes that code for homologues of global regulators, the function of which is unclear. In members of the family Enterobacteriaceae, cells express the global regulator H-NS and its paralogue StpA. In Escherichia coli, out of providing a molecular backup for H-NS, the role of StpA is poorly characterized. The enteroaggregative E. coli strain 042 carries, in addition to the hns and stpA genes, a third gene encoding an hns paralogue (hns2). We present in this paper information about its biological function. Transcriptomic analysis has shown that the H-NS2 protein targets a subset of the genes targeted by H-NS. Genes targeted by H-NS2 correspond mainly with horizontally transferred (HGT) genes and are also targeted by the Hha protein, a fine-tuner of H-NS activity. Compared with H-NS, H-NS2 expression levels are lower. In addition, H-NS2 expression exhibits specific features: it is sensitive to the growth temperature and to the nature of the culture medium. This novel H-NS paralogue is widespread within the Enterobacteriaceae. IMPORTANCE Global regulators such as H-NS play key relevant roles enabling bacterial cells to adapt to a changing environment. H-NS modulates both core and horizontally transferred (HGT) genes, but the mechanism by which H-NS can differentially regulate these genes remains to be elucidated. There are several instances of bacterial cells carrying genes that encode homologues of the global regulators. The question is what the roles of these proteins are. We noticed that the enteroaggregative E. coli strain 042 carries a new hitherto uncharacterized copy of the hns gene. We decided to investigate why this pathogenic E. coli strain requires an extra H-NS paralogue, termed H-NS2. In our work, we show that H-NS2 displays specific expression and regulatory properties. H-NS2 targets a subset of H-NS-specific genes and may help to differentially modulate core and HGT genes by the H-NS cellular pool.

Ciprofloxacin by-products in seawater environment in the presence and absence of gilt-head bream

The widespread use of pharmaceuticals has caused a growing concern on the presence of pharmaceuticals such as the antibiotic ciprofloxacin (CIPRO) in the aquatic environment, since they may exert adverse effects on non-target organisms, including fish. In order to study the uptake, distribution in different tissues (liver, muscle, brain and gill) and biofluids (plasma and bile), metabolism and elimination of CIPRO in gilt-head bream (Sparus aurata), controlled dosing experiments for 8 days at 200 μg/L concentration were carried out. CIPRO was only observed in bile at concentration up to 315 ± 4 ng/mL, probably due to its low octanol-water partition coefficient (log P = -2.4 at pH 7.4) and the zwitterionic behavior (pKa₁ = 5.76 and pKa₂ = 8.68). CIPRO by-products (BPs) were also identified in seawater environment, both in presence and absence of fish. The analysis done by means of liquid chromatography-high resolution mass spectrometry (hybrid quadrupole-Orbitrap) permitted the annotation of up to 35 BPs of CIPRO in seawater and bile, from which 30 structures were reported for the first time. These results confirm that CIPRO is very susceptible to photolysis, and that it goes through various phase I and phase II metabolisms in the fish. All these results suggested that, for a complete characterization of CIPRO exposure, BPs should also be included in the biomonitoring campaigns since they might also be toxicologically relevant.