Human-Associated Methicillin-Resistant Staphylococcus aureus from a Subtropical Recreational Marine Beach

Reports of Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) detected in marine environments have occurred since the early 1990s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible sources and to identify the risks to bathers of exposure to these organisms. During 40 days over 17 months, 1,001 water and 36 intertidal sand samples were collected by either bathers or investigators at a subtropical recreational beach. Methicillin-sensitive S. aureus (MSSA) and MRSA were isolated and identified using selective growth media and an organism-specific molecular marker. Antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) type, pulsed-field gel electrophoresis (PFGE) pattern, multi-locus sequence type (MLST), and staphylococcal protein A (spa) type were characterized for all MRSA. S. aureus was isolated from 248 (37 %) bather nearby water samples at a concentration range of <2–780 colony forming units per ml, 102 (31 %) ambient water samples at a concentration range of <2–260 colony forming units per ml, and 9 (25 %) sand samples. Within the sand environment, S. aureus was isolated more often from above the intertidal zone than from intermittently wet or inundated sand. A total of 1334 MSSA were isolated from 37 sampling days and 22 MRSA were isolated from ten sampling days. Seventeen of the 22 MRSA were identified by PFGE as the community-associated MRSA USA300. MRSA isolates were all SCCmec type IVa, encompassed five spa types (t008, t064, t622, t688, and t723), two MLST types (ST8 and ST5), and 21 of 22 isolates carried the genes for Panton–Valentine leukocidin. There was a correlation (r?=?0.45; p?=?0.05) between the daily average number of bathers and S. aureus in the water; however, no association between exposure to S. aureus in these waters and reported illness was found. This report supports the concept that humans are a potential direct source for S. aureus in marine waters.     

Cleanup of industrial effluents containing heavy metals: a new opportunity of valorising the biomass produced by brewing industry

Heavy metal pollution is a matter of concern in industrialised countries. Contrary to organic pollutants, heavy metals are not metabolically degraded. This fact has two main consequences: its bioremediation requires another strategy and heavy metals can be indefinitely recycled. Yeast cells of Saccharomyces cerevisiae are produced at high amounts as a by-product of brewing industry constituting a cheap raw material. In the present work, the possibility of valorising this type of biomass in the bioremediation of real industrial effluents containing heavy metals is reviewed. Given the auto-aggregation capacity (flocculation) of brewing yeast cells, a fast and off-cost yeast separation is achieved after the treatment of metal-laden effluent, which reduces the costs associated with the process. This is a critical issue when we are looking for an effective, eco-friendly, and low-cost technology. The possibility of the bioremediation of industrial effluents linked with the selective recovery of metals, in a strategy of simultaneous minimisation of environmental hazard of industrial wastes with financial benefits from reselling or recycling the metals, is discussed.     

Cathepsin L silencing enhances arsenic trioxide mediated in vitro cytotoxicity and apoptosis in glioblastoma U87MG spheroids

Despite improved treatment options, glioblastoma multiforme (GBM) remains the most aggressive brain tumour with the shortest post-diagnostic survival. Arsenite (As₂O₃) is already being used in the treatment of acute promyelocytic leukaemia (APL), yet its effects on GBM have not been evaluated in detail. In U87MG cell monolayers, we have previously shown that arsenite cytotoxicity significantly increases upon transient inhibition of lysosomal protease Cathepsin L (CatL). As multicellular spheroids more closely represent in vivo tumours, we aimed to evaluate the impact of permanent CatL silencing on arsenite treatment in U87MG spheroids. CatL was stably silenced using shRNA expression plasmid packed lentiviruses. By using metabolic- and cell viability assays, we demonstrated that long-term CatL silencing significantly increased arsenite cytotoxicity in U87MG spheroids. Silenced CatL also increased arsenite-mediated apoptosis in spheroids via elevated p53 expression, Bax/Bcl2 ratio and caspase 3/7 activity, though with lower efficacy than in monolayers. Arsenite cytotoxicity was enhanced by lower CatL activity, since similar cytotoxicity increase was also observed using the novel CatL inhibitor AT094. The results have significant translational impact, since stable CatL silencing would enable the application of lower systemic doses of arsenite to achieve the desired cytotoxic effects on GBMs in vivo.     

The first case of fatal pneumonia caused by Panton–Valentine leukocidin-producing Staphylococcus aureus in an infant in the Czech Republic

Panton–Valentine leukocidin-producing strains of Staphylococcus aureus can cause severe skin and soft tissue infections and necrotizing pneumonia with a high mortality rate. This is a report on the first case of fatal pneumonia with mediastinitis in an infant in the Czech Republic. The causative agent was a methicillin-susceptible S. aureus strain with pronounced production of the PVL toxin and hyperproduction of enterotoxin A.     

Involvement of virulence properties and antibiotic resistance in Escherichia coli strains causing pyelonephritis in children

A total of 145 Escherichia coli strains causing pyelonephritis in children were investigated for the prevalence of genes encoding the following virulence factors (VFs): P fimbria (67.6?%), S fimbria (53.8?%), AFA adhesins (2.8?%), cytotoxic necrotizing factor 1 (37.9?%), ??-hemolysin (41.4?%), and aerobactin (71.7?%). One hundred and thirty-six (93.8?%) isolates harbored at least one of the virulence genes detected in the present study. Statistically significant co-occurrent presence of two VF genes was found for ??-hly?Ccnf1, ??-hly?Csfa, cnf1?Csfa (p?<?0.001), and ??-hly?Cpap (p?=?0.001). Twenty-six profiles of VF genes were detected in this study. The combinations of aer?Cpap and aer?Cpap?Csfa?C??-hly?Ccnf1 were presented with the highest frequency??both of them in 28 isolates (19.3?%). All E. coli strains included in the study were susceptible to meropenem, amikacin, and tobramycin; the highest frequency resistance was found toward ampicillin (43.4?%), piperacillin (31.7?%), tetracycline (15.9?%), and trimethoprim/sulfamethoxazole (11.7?%). The resistance to the other tested antimicrobial drugs did not exceed 3?% incidence. Overall, 55.9?% strains were susceptible to all tested anti-infective agents. Antimicrobial resistance of E. coli strains toward trimethoprim/sulfamethoxazole statistically significantly correlated with the presence of ??-hly (p?<?0.001), sfa (p?<?0.01), and cnf1 (p?<?0.05).     

Influence of meteorological parameters on Olea flowering date and airborne pollen concentration in four regions of Portugal

For calculating the total annual Olea pollen concentration, the onset of the main pollen season and the peak pollen concentration dates, using data from 1998 to 2004, predictive models were developed using multiple regression analysis. Four Portuguese regions were studied: Reguengos de Monsaraz, Valença do Douro, Braga and Elvas. The effect of some meteorological parameters such as temperature and precipitation on Olea spatial and temporal airborne pollen distribution was studied. The best correlations were found when only the pre‐peak period was used, with thermal parameters (maximum temperature) showing the highest correlation with airborne pollen distribution. Independent variables, selected by regression analysis for the predictive models, with the greatest influence on the Olea main pollen season features were accumulated number of days with rain and rainfall in the previous autumn, and temperatures (average and minimum) from January through March. The models predict 59 to 99% of the total airborne pollen concentration recorded and the initial and peak concentration dates of the main Olea pollen season.     

DNA damage induction and antiproliferative activity of vanadium(V) oxido monoperoxido complex containing two bidentate heteroligands

Several peroxidovanadium(V) complexes have been shown as a potent anticancer agents. The aim of this study was to investigate the interaction of monoperoxidovanadium(V) complex Pr₄N[VO(O₂)(ox)(phen)], (Vphen), [phen = 1,10-phenantroline, ox = oxalate(2?) and Pr₄N = tetra(n-propyl)ammonium(1+)] with DNA. UV–Vis spectrophotometry and the alkaline single-cell gel electrophoresis (SCGE, the comet assay) were used to examine the possibility of the vanadium(V) complex to induce changes in DNA. The interaction of Vphen with calf thymus DNA resulted in absorption hyperchromicity in DNA spectrum and shift of the absorption band of DNA to longer wavelengths for the [complex]/[DNA] concentration ratio equals to 4 and after 60 min of incubation. The rise in DNA absorption (by 34%) and bathochromic shift (Δλ_max = 6 nm) are indicative of the interaction between DNA and the complex molecules. DNA strand breaks in cellular DNA were investigated using the comet assay. The human lymphocytes were exposed to various concentrations of Vphen for 30 min. The results revealed that Vphen contributed to the DNA damage expressed as DNA strand breaks in concentration dependent manner. The used concentrations of Vphen (ranging from 0.1 to 100 μmol/L) caused higher DNA damage in lymphocytes compared to untreated cells (from 1.2 times for 0.1 μmol/L to 1.8 times for 100 μmol/L). Vphen was screened for its potential antitumor activity towards murine leukemia cell line L1210. Vphen exhibited significant antiproliferative activity depending on its concentration and time of exposure. The IC₅₀ values were 0.247 μg/mL (0.45 μmol/L) for 24 h, 0.671 μg/mL (1.21 μmol/L) for 48 h and 0.627 μg/mL (1.13 μmol/L) for 72 h.     

Soybean lecithin-based extender as an alternative for goat sperm cryopreservation

The aim of this study was to evaluate the effect of different concentrations of soybean lecithin (SL) in extenders for sperm goat cryopreservation. Sexually mature male Saanen goats (n = 4) were used, and the ejaculates were obtained using an artificial vagina method. The semen samples were pooled and diluted in a skim milk-based extender (control group; CG) or Tris extender supplemented with SL at different concentrations (G1 = 0.04%, SL G2 = 0.08% SL and G3 = 0.16%) for a final concentration of 240 × 10⁶ spermatozoa/mL. The semen samples were packed in straws (0.25 mL), frozen using an automated system and stored in liquid nitrogen (?196 °C). After thawing (37 °C/30 s), the samples were evaluated for sperm quality parameters, including sperm motility, membrane integrity, acrosome integrity and mitochondrial activity. No significant difference was observed among the experimental and control groups for all of the parameters (P > 0.05). However, even though the control group presented a significantly lower mitochondrial membrane potential compared to fresh semen (P < 0.05), the same did not occur for the extender supplemented with soybean lecithin, that is, it did not differ from fresh sperm (P > 0.05). The extender containing soybean lecithin at different concentrations preserved the sperm quality parameters in a manner similar to the conventional skim milk-based extender. Thus, it is concluded that an extender containing soybean lecithin as the lipoprotein source can be used for freezing goat semen.     

Modelling shifts in agroclimate and crop cultivar response under climate change

This paper aims: (i) to identify at national scale areas where crop yield formation is currently most prone to climate‐induced stresses, (ii) to evaluate how the severity of these stresses is likely to develop in time and space, and (iii) to appraise and quantify the performance of two strategies for adapting crop cultivation to a wide range of (uncertain) climate change projections. To this end we made use of extensive climate, crop, and soil data, and of two modelling tools: N‐AgriCLIM and the WOFOST crop simulation model. N‐AgriCLIM was developed for the automatic generation of indicators describing basic agroclimatic conditions and was applied over the whole of Finland. WOFOST was used to simulate detailed crop responses at four representative locations. N‐AgriCLIM calculations have been performed nationally for 3829 grid boxes at a 10 × 10 km resolution and for 32 climate scenarios. Ranges of projected shifts in indicator values for heat, drought and other crop‐relevant stresses across the scenarios vary widely – so do the spatial patterns of change. Overall, under reference climate the most risk‐prone areas for spring cereals are found in south‐west Finland, shifting to south‐east Finland towards the end of this century. Conditions for grass are likely to improve. WOFOST simulation results suggest that CO₂ fertilization and adjusted sowing combined can lead to small yield increases of current barley cultivars under most climate scenarios on favourable soils, but not under extreme climate scenarios and poor soils. This information can be valuable for appraising alternative adaptation strategies. It facilitates the identification of regions in which climatic changes might be rapid or otherwise notable for crop production, requiring a more detailed evaluation of adaptation measures. The results also suggest that utilizing the diversity of cultivar responses seems beneficial given the high uncertainty in climate change projections.