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Plant parasitic nematodes (PPN) are important pests of numerous agricultural crops especially vegetables, able to cause remarkable yield losses correlated to soil nematode population densities at sowing or transplant. The concern on environmental risks, stemming from the use of chemical pesticides acting as nematicides, compels to their replacement with more sustainable pest control strategies. To verify the effect of aqueous extracts of the agro-industry waste coffee silverskin (CS) and brewers’ spent grain (BSG) on the widespread root-knot nematode Meloidogyne incognita, and on the physiology of tomato plants, a pot experiment was carried out in a glasshouse at 25 ± 2 °C. The possible phytotoxicity of CS and BSG extracts was assessed on garden cress seeds. Tomato plants (landrace of Apulia Region) were transplanted in an artificial nematode infested soil with an initial population density of 3.17 eggs and juveniles/mL soil. CS and BSG were applied at rates of 50 and 100 % (1L/pot). Untreated and Fenamiphos EC 240 (nematicide) (0.01 μL a.i./mL soil) treated plants were used as controls. Reactive oxygen species (ROS) and chlorophyll content of tomato plants were estimated during the experiment. CS extract, at both doses, significantly reduced nematode population in comparison to the untreated control, although it was less effective than Fenamiphos. BSG extract did not reduce final nematode population compared to the control. Ten days after the first treatment, CS 100 %, BSG 50 % and BSG 100% elicited the highest ROS values, which considerably affected the growth of tomato plants in comparison to the untreated plants. The control of these pests is meeting with difficulties because of the current national and international regulations in force, which are limiting the use of synthetic nematicides. Therefore, CS extracts could assume economic relevance, as alternative products to be used in sustainable strategies for nematode management.

Extremophiles are organisms able to thrive in extreme environmental conditions and some of them show the ability to survive high doses of heavy metals thanks to defensive mechanisms provided by primary and secondary metabolic products, i.e., extremolytes, lipids, and extremozymes. This is why there is a growing scientific and industrial interest in the use of thermophilic bacteria in a host of tasks, from the environmental detoxification of heavy metal to industrial activities, such as bio-machining and bio-metallurgy. In this work Thermus thermophilus was challenged against increasing Pb 2+ concentrations spanning from 0 to 300 ppm in order to ascertain the sensitiveness of this bacteria to the Pb environmental pollution and to give an insight on its heavy metal resistance mechanisms. Analysis of growth parameters, enzyme activities, protein profiles, and lipid membrane modifications were carried out. In addition, genotyping analysis of bacteria grown in the presence of Pb 2+ , using random amplified polymorphic DNA-PCR and DNA melting evaluation, were also performed. A better knowledge of the response of thermophilic bacteria to the different pollutants, as heavy metals, is necessary for optimizing their use in remediation or decontamination processes., Competing Interests: The authors declare no conflict of interest.

The occurrence of Clostridium difficile in nine wastewater treatment plants in the Ticino Canton (southern Switzerland) was investigated. The samples were collected from raw sewage influents and from treated effluents. Forty-seven out of 55 characterized C. difficile strains belonged to 13 different reference PCR ribotypes (009, 010, 014, 015, 039, 052, 053, 066, 070, 078, 101, 106, and 117), whereas 8 strains did not match any of those available in our libraries. The most frequently isolated ribotype (40%) was 078, isolated from six wastewater treatment plants, whereas ribotype 066, a toxigenic emerging ribotype isolated from patients admitted to hospitals in Europe and Switzerland, was isolated from the outgoing effluent of one plant. The majority of the isolates (85%) were toxigenic. Forty-nine percent of them produced toxin A, toxin B, and the binary toxin (toxigenic profile A(+) B(+) CDT(+)), whereas 51% showed the profile A(+) B(+) CDT(-). Interestingly, eight ribotypes (010, 014, 015, 039, 066, 078, 101, and 106) were among the riboprofiles isolated from symptomatic patients admitted to the hospitals of the Ticino Canton in 2010. Despite the limitation of sampling, this study highlights that toxigenic ribotypes of C. difficile involved in human infections may occur in both incoming and outgoing biological wastewater treatment plants. Such a finding raises concern about the possible contamination of water bodies that receive wastewater treatment plant effluents and about the safe reuse of treated wastewater.

Six thermophilic extremophiles, Anoxybacillus amylolyticus, Geobacillus thermoleovorans, Geobacillus thermoleovorans subspecies stromboliensis, Geobacillus toebii subspecies decanicus, Bacillus thermantarcticus and Thermus oshimai, isolated from different environmental sites, were studied for their heavy metal resistance. The effects of heavy metals on microorganism growth were studied here in a pilot fermenter tank spiked with various trace metals, (Ni(2+), Zn(2+), Co(2+), Hg(2+), Mn(2+), Cr(6+), Cu(2+), Fe(3+) and Cd(2+)) at concentrations spanning from 0.01 to 20 mM. Trace metal toxicity varied depending on the species and metal considered. Among the tested microorganisms, attention was focused on alpha-amylase producing-A. amylolyticus, an acidothermophilic bacterium recently isolated from geothermal soil samples from Mount Rittmann in Antarctica. The effect of heavy metals on the biosynthesis and activity of alpha-amylase of A. amylolyticus was investigated. When bacteria were grown in the presence of heavy metals, a decrease in alpha-amylase activity, correlated with a decrease in alpha-amylase production, was observed, suggesting an effect on the biosynthesis of the enzyme. A decrease in enzyme activity was also noted when the assay was performed in the presence of heavy metals. Thus, alpha-amylase could represent a potential sensitive bioassay for detecting trace heavy metals.

A case of food poisoning outbreak involving Aeromonas hydrophila is reported in this study. A group of 27 people consumed a typical Swedish food "landgång" which is a type of smörgåsbord containing shrimps with mayonnaise, liver paté, ham, sausage, and legume salad which was purchased from a food store. Twenty-two of the 27 persons became ill within 20-34 hr of consumption of the food and reported the symptoms ranging from severe acute diarrhea, abdominal pain, headache, fever and vomiting. One person also fainted. The symptoms lasted for a couple of days. Of the remaining 5 healthy persons who consumed the left-over food the next day, 2 became ill with similar symptoms. The bacteriological examination of left-over food samples resulted in the isolation of A. hydrophila from shrimps with mayonnaise, smoked sausage, liver paté and boiled ham. The total number of A. hydrophila in these foods were log 10(6) to log > 10(7) organisms per gram of food sample. A. hydrophila was however, not isolated from legume/mayonnaise salad samples. All the food samples tested showed low numbers of other expected food contaminating organisms such as coliforms at 37 C and 44 C, fecal streptococci, Staphylococcus aureus, fungi and yeast etc., while Bacillus cereus, Clostridium perfringens and Salmonella spp. were not detected in the food samples. Investigations of the virulence profiles of the A. hydrophila isolates showed their capacity to produce beta-hemolysin, cytotoxins, cytotonic toxins, enterotoxins, and adhesion to and invasion of human intestinal (Henle 407) cells in culture.

An outbreak of Aeromonas hydrophila infection with a high rate of mortality (95%) in turtles (Pseudemis scripta) in Italy is reported. Pure cultures of the pathogen were isolated from liver, lung, kidney, and heart specimens of the turtles. The A. hydrophila isolate was resistant to amoxicillin, ampicillin, cephalothin, and trimethoprim-sulfamethoxazole but was sensitive to a number of other antibiotics tested. The study indicates that pet turtles can act as reservoirs of this pathogen and may play an important role in the etiology of Aeromonas-associated human infections.