病原微生物感染的蛋白质组学研究

基于质谱的蛋白质组学在近20年有巨大的发展。在其应用中,病原微生物和与感染相关的蛋白质组学具有重要科学意义,体系复杂度又相对较小,一直受到广泛关注并有较快发展。本文从感染中病原微生物和宿主的蛋白质组学两方面入手,简要综述应用蛋白质组学研究感染过程的相关工作,着重介绍该领域近几年的主要进展,并对其发展做出展望。     

Sorting out the value of spectroscopic tools to assess the Colletotrichum acutatum impact in olive cultivars with different susceptibilities

The olive tree (Olea europaea L.) can be affected by Colletotrichum acutatum, causing a loss of yield and quality of the final products, whilst the incidence of this fungal infection depends on several factors, including cultivar susceptibility. Thus, the effect of C. acutatum infection in cultivars displaying different susceptibilities to this fungal disease (‘Galega Vulgar’ ‐ susceptible, ‘Cobrançosa’ ‐ moderately susceptible, ‘Picual’ ‐ tolerant) has been assessed through spectrophotometric methods and HPLC, while the FTIR spectra of the cuticles have been concomitantly registered, resorting to the ATR accessory. With the support of multivariate analysis, these spectra allowed to discriminate olives with distinct infection times, besides retrieving evidences concerning the different susceptibility of each cultivar, while these observations were reinforced by the spectrophotometric and chromatographic methods. Furthermore, the assessment of the phenolic profile evidenced individual compounds in the distinct cultivars, so as their variations in response to the fungal infection.     

Fungal keratitis infected eye treatment with antibiotic-loaded zinc ions tagged polyvinyl acetate phthalate-g-polypyrrole drug carrier

Currently, the treatment of fungal keratitis (FK) infection remains a major clinical challenge, and current investigations, development in the field have widened approaches. The present work was aimed to synthesis a dual role novel carrier system consisting of Ofloxacin (OFL) and Nepafenac (NF) hydrophobic drugs incorporated in Zinc ions (Zn²⁺) tagged Polyvinyl acetate phthalate (PVAP) grafted Polypyrrole (PPy) carrier (OFL&NF-Zn²⁺/PVAP-g-PPy) to treat FK infection. The FT-IR, SEM, and dynamic light scattering revealed the carrier chemical structure, spherical shape, and the average particle size of 691.3 ± 1 nm. The carrier’s entrapment of OFL and NF drugs has been observed at 78.23% and 60.03%. The carrier exhibited significant antifungal activity at the concentration of 58 mg mL⁻¹ against Candida albicans which was lower than that of the free ofloxacin. The cell viability results suggested up to 70 μg/mL concentration of OFL&NF-Zn²⁺/PVAP-g-PPy did not induce any cytotoxicity on cultured ADSC cells at 48 h treatment time. It confirms the fact that the OFL&NF-Zn²⁺/PVAP-g-PPy carrier showed good biocompatibility and good anti-fungal activity. Thus the carriers provide a significant potential to improve the bioavailability of topically applied drugs to treat fungal eye infection.     

99mTc-amoxicillin: A novel radiopharmaceutical for infection imaging

Amoxicillin, a penicillin derivative was synthesized as ready-to-used single vial kit and radiolabeled with technetium-99m. Various trials have been carried out to optimize the concentration of stannous chloride, amoxicillin, pH and reaction time. Radiochemical purity, in vitro and in vivo stability, partition co-efficient, protein binding and biodistribution in rabbit infected with Streptococcus pneumoniae were studied. The biodistribution studies in rabbit showed that ^99mTc-amoxicillin started to accumulate in the infected area at 1-h postadministration. ^99mTc-amoxicillin may prove itself as potential novel radiopharmaceutical for imaging infections caused by many bacteria.     

Inflammation markers in point-of-care testing (POCT)

Inflammation is a central issue in medicine. Inflammatory processes may be local or systemic, acute or chronic, and they may be benign or fatal. In bacterial or viral infections fast and reliable diagnosis is essential for appropriate treatment, e.g. antimicrobial therapy. The time to diagnosis is critical because uncontrolled infections may lead to sepsis with a mortality rate close to 50%. Beside clinical signs, laboratory markers are important in detecting, differentiating, and monitoring inflammation, particularly acute infections. Currently several inflammation markers including leukocyte count and leukocyte differentiation, C-reactive protein (CRP), procalcitonin (PCT), and interleukins (IL) 6 and 8, is available, and potential future serum markers are under development. In this article the clinical use of these markers in routine laboratory and in point-of-care testing is described and the diagnostic value of the four groups of laboratory marker is compared. Current data show that leukocyte count or, better, neutrophil count, CRP, and PCT are well suited to support of rapid diagnosis of inflammation and infections in children and adults whereas measurement of IL-6 and 8 are preferable for detection of sepsis in neonates.     

Assessing the heterogeneity of a disease spread through a community

A multivariate non-parametric test and a semi-parametric regression model via counting process are proposed for detecting the heterogeneity of a disease spread through a community. The infection rates are allowed to depend on time in an arbitrary manner. Infectious data usually are not completely observed, nevertheless only partial information of the epidemic is needed for the suggested methods. The testing procedures and the associated methods of analysis are illustrated with reference to epidemics of respiratory disease on the Island of Tristan da Cunha in the South Atlantic     

Infectious Behavior in Photo-oxidation of Polymers

When a polymer is used together with others,its aging process will be affected by the adjacent polymers.This infectious behavior between polymers makes the aging process more complex than that of an individual material.In this study,infectious behavior in photooxidation of polymers was investigated.Polypropylenes(PPs),an unstabilized PP and a commercial PP,were chosen as the infection sources.Six typical polymers,high density polyethylene(HDPE),low density polyethylene(LDPE),polystyrene(PS),polycarbonate(PC),poly(ethylene terephthalate)(PET),and polyamide 6(PA6),were used as the targets.The degree of oxidation of the targets was evaluated by attenuated total reflection-Fourier transform infrared spectroscopy(ATR-FTIR).An accelerating effect of two infection sources on the photo-oxidation of the target polymers was observed.Potential infectious agents from the infection sources were detected by pyrolysis-gas chromatography-mass spectrometry(Py-GC-MS)and gas chromatography(GC).The acceleration effect of two main infectious agents,i.e.acetone and acetic acid,on the photo-oxidation of the commercial PP was verified.The infectious effect of the infection source on the target polymer was considered to be a comprehensive result of the effects of a variety of infectious agents.     

Global dynamics of a two-patch SIS model with infection during transport

A two-patch SIS model is formulated and studied. The standard incidence rate and mass-action incidence rate are used within each patch and during transport, respectively. The basic reproduction number is calculated and the global dynamics is investigated. The simulation results show the influence of travel rates, the different dynamics by using standard incidence rate and mass-action incidence rate. The importance of border screening is also explored by numerical simulation.     

Oxygen-carrying biomimetic nanoplatform for sonodynamic killing of bacteria and treatment of infection diseases

Among various novel antimicrobial therapies, sonodynamic therapy (SDT) exhibits its advantages for the treatment of bacterial infections due to its high penetration depth and low side effects. In this study, a new nanosonosensitizer (HFH@ZIF-8) that loads sonosensitizer hematoporphyrin monomethyl ether (HMME) into zeolitic imidazolate framework-8 (ZIF-8), was constructed for killing multidrug-resistant (MDR) bacteria and treatment of in vivo infection diseases by SDT. In particular, the developed HFH@ZIF-8 exhibited enhanced water-solubility, good biocompatibility, and improved disease-targeting capability for delivering and releasing HMME and ablating the infected lesion. More importantly, the presence of oxygen-carrying hemoglobin for HFH@ZIF-8 can offer sufficient oxygen consumption by SDT, augmenting the efficacy of SDT by improving ROS generating efficiency against deep tissue multidrug-resistant bacterial infection. Therefore, this study paves a new avenue for treating infection disease, particularly for antibiotic resistant bacterial infection.     

A discrete time version for models of population dynamics in the presence of an infection

We present a set of difference equations which represents the discrete counterpart of a large class of continuous model concerning the dynamics of an infection in an organism or in a host population. The limiting behavior of the discrete model is studied and a threshold parameter playing the role of the basic reproduction number is derived.