The repeated use of conventional synthetic pesticides in crop protection leads to resistance development by pests along with a negative impact on the environment, particularly non-target arthropods. Plant-derived active compounds, such as essential oils (EOs), play a key role in sustainably controlling pests. The lethal and sublethal activity of citrus peel EOs as emulsions and included in polyethylene glycol (PEG) nanoparticles (EO-NPs) was determined against the invasive tomato pest Tuta absoluta. Their effects on the plants were also assessed. The results showed an overall good insecticidal activity of the compounds tested, with a higher mortality through contact on eggs and larvae by EO emulsions and through ingestion on larvae by EO-NPs. The nanoformulation also significantly reduced the visible toxic effects on the plants. The data collected suggest that these natural compounds, especially when nanoformulated, could be successfully used in integrated pest management programs for T. absoluta.

Noble metal nanomaterials, such as gold or silver nanoparticles, exhibit unique photonic, electronic, catalytic and therapeutic properties. The high versatility in their synthesis, especially size and shape features, as well as in the surface functionalization by, e.g., physisorption, direct chemisorption of thiol derivatives and covalent binding through bifunctional linkers or specific affinity interactions, prompted their widespread and rising use as multifunctional platforms for theranostic purposes. In this paper, the recent developments of gold and silver nanoparticles for application in biosensing, medical imaging, diagnosis and therapy is reviewed from the following five aspects: (1) the gold and silver nanomaterials intrinsic properties of biomedical interest; (2) the synthesis of noble metal nanoparticles by chemical, physical and biological/green processes; (3) the applications of gold and silver nanoparticles in imaging, diagnostic and therapeutic mode; (4) the surface functionalization processes for targeting, controlled drug loading and release, triggered pathways of cellular uptake and tissue distribution; and (5) nanotoxicity. The historical developments and the most recent applications have been focused on, together with suggested strategies for future more efficacious, targeted delivery.

Threatening sporadic outbreaks of avian influenza and the H1N1 pandemic of 2009 highlight the need for rapid and accurate detection and typing of influenza viruses. In this paper, we describe the validation of the VereFlu™ Lab-on-Chip Influenza Assay, which is based on the integration of two technologies: multiplex reverse transcription (RT)-PCR followed by microarray amplicon detection. This assay simultaneously detects five influenza virus subtypes, including the 2009 pandemic influenza A (H1N1), seasonal H1N1, H3N2, H5N1 and influenza B virus. The VereFlu™ assay was clinically validated in Singapore and compared against reference methods of real-time PCR, virus detection by immunofluorescence of cell cultures and sequencing. A sensitivity and specificity of 96.8% and 92.8%, respectively, was demonstrated for pandemic H1N1; 95.7% and 100%, respectively, for seasonal H1N1; 91.2% and 97.6%, respectively, for seasonal H3N2; 95.2% and 100%, respectively, for influenza B. Additional evaluations carried out at the World Health Organization (WHO) Collaborating Centre, Melbourne, Australia, confirmed that the test was able to reliably detect H5N1. This portable, fast time-to-answer (3 hours) device is particularly suited for diagnostic applications of detection, differentiation and identification of human influenza virus subtypes.

We describe two mutants of Mycoplasma hominis PG-21 which show resistance to 16-membered macrolides but susceptibility to lincosamides, obtained by in vitro exposure to increasing doses of josamycin. The 23S rRNA gene showed that each had a mutation (A2062G and A2062T) corresponding to nucleotide 2062 in Escherichia coli, which was associated with the acquired phenotype.The genetic bases for macrolide-lincosamide-streptogramin B group resistance have been extensively studied for many bacteria (2, 4-6, 16, 18, 27, 29, 30, 32-34) and mycoplasmas (8, 14). In Mycoplasma pneumoniae (14,22), as well as in other microorganisms, resistance to erythromycin has been associated with point mutations (A-to-G transition) in the loop of domain V of the 23S rRNA (2, 4-6, 8, 16, 18, 27, 29, 30, 32). Specific residues within domain V of 23S rRNA are involved in the action of macrolide-lincosamide-streptogramin antibiotics and chloramphenicol (2-6, 8, 11, 14-18, 20, 27-30, 32). It is well known that Mycoplasma hominis and many other mycoplasmas are resistant to erythromycin but susceptible to 16-membered macrolides (josamycin and miocamycin) (1, 7-9, 19, 23) and lincosamides (23). Recently the natural resistance of M. hominis to erythromycin has been associated with a guanine-to-adenine transition in position 2057 (Escherichia coli numbering), located in the central loop of the 23S rRNA domain V (8), and such a transition is present in Mycoplasma flocculare and Mycoplasma hyopneumoniae, which are also resistant to erythromycin (24).These features encouraged us to investigate the ability of josamycin to select for resistance in M. hominis strains, in order to see whether the acquired resistance pattern includes either macrolides only or both macrolides and lincosamides and to establish a possible relationship between the resistant phenotype and the appearance of specific point mutations in the region coding for the peptidyl transferase loop in the 23S rRNA gene.The type strain M. hominis PG-21 was chosen for our study. The strain was grown in SP-4 broth (pH 7.0) (7,8,21,25,26,31). The MIC was determined by a broth microdilution assay as previously described (7-9, 23).For multistep selection for resistance, SP-4 broth medium containing doubling concentrations of josamycin was inoculated with strain PG-21, incubated at 37°C, and examined for growth each day. To test for the development of resistance, 0.1 ml of the culture was withdrawn from each tube every day and spread on an SP-4 agar plate containing 1 g of josamycin/ml. All the colonies growing on josamycin-agar were challenged with increasing concentrations of the drug in broth (from 16 to 128 g/ml). All selected mutants were single colony purified on SP-4 agar-josamycin and drug-free SP-4 agar. Resistance to josamycin was assayed after the microrganisms were repeatedly transferred to antibiotic-free media.Two resistant clones of the M. hominis PG-21 strain were obtained by the selection procedure outlined above and were found to be stably resistant. The resistance/susceptibi...

No abstract