A stochastic assessment of the public health risks of fluoroquinolone resistance Campylobacter and the use of the drug in broiler production in Japan

Purpose: Antimicrobial resistance (AMR) is a major global public health and a food safety issue. Risk analysis is an essential tool in assessing the risk to human health from foodborne AMR microorganisms and determining appropriate risk management strategies to control those risks. Although quantitative risk assessments are encouraged and have been performed in some EU countries and the US, so far only qualitative risk assessments are performed in Japan. This project was commissioned by the Japan Food Safety Commission in the context of its programme to develop a quantitative risk assessment, with Campylobacter in broiler and use of fluoroquinolone (FQ) for broiler production as an example. Methods: The risk assessment model was subdivided into the release, exposure, and consequence assessment sections. In the release section, FQ resistance mechanism and data from Japanese Veterinary Antimicrobial Resistance Monitoring Program were utilized for the model development. The model output was percentage of FQ resistance Campylobacter (FRC) among broiler borne human campylobacteriosis. In order to take uncertainties in the data into account, the model was built, and simulations were performed using @Risk 4.5 (Palisade Corp.) . Results: The average percentage of broilers infected with FRC was estimated to be 34.0%. Among FRC strains, 10.4% carried a mutation at Thr86Ile of gyrA with overexpression producing strains of efflux pump, 20.8% carried a same mutation of gyrA with low expression producing strains of efflux pump, and 2.8% carried a mutation of GyrA other places than Thr86Ile. The estimated that an average and the maximum annual number of Campylobacter infections per person were 1.02, and 88 times, respectively. Conclusions: In the maximum (88 infections per year) scenario, the patient is estimated to be infected with FRC 30 times, and 28 times out of 30 times, he or she is estimated to be infected with Campylobacter with a mutation of Thr86Ile of GyrA. Relevance: By using this model, use of FQ in the farm and the effect on the percentage of FRC in broilers was not identified. We couldn't find any adverse human health effects associated with FRC strains

Oxidative cleavage-based near-infrared fluorescent probe for hypochlorous acid detection and myeloperoxidase activity evaluation

10.1021/ac403603rAnalytical Chemistry861671-677ANCH

Semiconducting polymer nanoparticles as photoacoustic molecular imaging probes in living mice

Photoacoustic (PA) imaging holds great promise for the visualization of physiology and pathology at the molecular level with deep tissue penetration and fine spatial resolution. To fully utilize this potential, PA molecular imaging probes have to be developed. Herein we introduce near infrared (NIR) light absorbing semiconducting polymer nanoparticles (SPNs) as a new class of contrast agents for PA molecular imaging. SPNs can produce stronger signal than commonly used single-wall carbon nanotubes and gold nanorods on a per mass basis, permitting whole-body lymph node PA mapping in living mice at a low systematic injection mass. Furthermore, SPNs possess high structural flexibility, narrow PA spectral profiles, and strong resistance to photodegradation and oxidation, which enables development of the first NIR ratiometric PA probe for in vivo real-time imaging of reactive oxygen species—vital chemical mediators of many diseases. These results demonstrate SPNs an ideal nanoplatform for developing PA molecular probes

Bovine Serum Albumin Nanoparticles with Fluorogenic Near-IR-Emitting Squaraine Dyes

Two squaraine (SQ) dyes, N-propanesulfonate-benzothiazolium squaraine (SQ-1) and N-propanesulfonate-benzoindolium squaraine (SQ-2), were synthesized with sulfonate groups to increase water solubility. Both dyes are almost nonfluorescent in aqueous solution with fluorescent quantum yields of 0.03, but exhibited fluorescence enhancement after noncovalently binding with bovine serum albumin (BSA). Upon addition of BSA, the fluorescence intensity increased by ca. a factor of 10, along with a 10-fold extension in the fluorescence lifetime. SQ-1 and SQ-2 interacted with BSA efficiently and appeared to show a preference for binding at site II, which involves combinational effects of electrostatic and hydrophobic interactions. The fluorogenic squaraine dyes were then used to label BSA, forming BSA-based nanoparticles (NPs) through noncovalent binding. The resulting BSA-SQ NPs exhibited enhanced near-IR fluorescence and reduced aggregation of the squaraine moiety. The BSA-SQ NPs were used for cell incubation and bioimaging studies. Confocal fluorescent images were obtained for HCT 116 cells incubated with the BSA-SQ NPs and LysoSensor Green, demonstrating the utility of the NP probes for intracellular imaging. This strategy ovecomes the generally low fluorescence emission of SQ dyes in water and aggregation-reduced fluorescence, providing a versatile strategy for sensing and imaging in biological environments