Alleviation of enterotoxigenic Escherichia coli challenge by recombinant Lactobacillus plantarum expressing a FaeG- and DC-targeting peptide fusion protein

FaeG is the major subunit of K88 fimbriae. These cell surface attachments are considered to be the major virulence factor of enterotoxigenic Escherichia coli (ETEC), which causes diarrhoea in piglets. The use of dendritic cell-targeting peptide (DCpep) has been demonstrated to be an effective approach to enhance the immunity of vaccines. Lactobacillus plantarum is an attractive candidate for oral vaccination owing to its beneficial effects and safety. In this study, L. plantarum was employed to deliver a FaeG-DCpep fusion antigen, and the immune response in mice was evaluated. The synthesis of FaeG-DCpep dramatically increased the adhesion of recombinant L. plantarum (RLP) to IPEC-J2 cell surfaces, resulting in direct competition between L. plantarum and ETEC during adhesion assays. Significantly higher levels of body weight gain, sera immunoglobulin G and intestinal immunoglobulin A were observed in BALB/c mice immunised with RLP. In addition, the number of CD19+ B cells and CD11c+DC cells and the expression levels of several cytokines in the spleen and lymph nodes increased significantly compared to non-immunised mice. The oral administration of RLP also alleviated the symptoms of ETEC challenge, as shown by haematoxylin-eosin staining, indicating that RLP may be an efficient vaccine candidate.

The Effects of Lentivirus-mediated shRNA Interference Targeting Mcl-1 on Growth of NK/T-cell Lymphoma

Myeloid leukemia-1 (Mcl-1) gene has been reported as an important factor in various types of cancer, but little research was processed on natural killer (NK)/T-cell lymphoma, a kind of a highly aggressive disease with a poor prognosis. Here we investigated the expression of Mcl-1 in seven lymphoma cell lines and its potential role as a molecular drug target for NK/T-cell lymphoma therapy by using lentivirus-mediated shRNA interference targeting Mcl-1 (lenti-shMcl-1). In our study, the expression of Mcl-1 in different lymphoma cell lines were evaluated firstly, after that lenti-shMcl-1 was constructed and transduced into NK/T-cell lymphoma cell line SNK-6 which had a high level expression of Mcl-1. Methylthiazolete-Trazolium (MTT) assay and flow cytometry (FCA) were employed to detect the status of proliferation and apoptosis after infection. Lastly we investigated the effects of chemotherapy agent vincristine (VCR) combination with lenti-shMcl-1 by MTT and FCA assay. The results showed that Mcl-1 gene expressed in all seven lymphoma cell lines at different levels. Recombinant lentiviruses could infect SNK-6 cells effectively. Mcl-1 expression level was remarkably down-regulated after infection with lenti-shMcl-1. The growth of SNK-6 cells was inhibited significantly through apoptosis pathway. Otherwise, lenti-shMcl-1 also revealed a significant chemosensitizing effect in combination with vincristine. In a word, we demonstrated that lenti-shMcl-1 had a significant anti-NK/T cell lymphoma effect and targeting Mcl-1 therapy could be a promising novel approach in treatment of lymphoma.

[Surveillance on the epidemiological and etiological characteristics of hand-foot-mouth disease during the outbreaks in three cities of Jiangsu province, 2012-2015]

Objective: To analyze the epidemiological and etiological characteristics through monitoring the outbreaks of hand-foot-mouth disease (HFMD), in three cities of Jiangsu province from 2012 to 2015 and to provide evidence for prevention and control of the disease. Methods: Data related to cases of HFMD during the outbreaks was collected through active surveillance programs in three cities of Jiangsu province, under the guidelines of clusters and outbreaks of HFMD (2012 edition HFMD). Features related to clusters and outbreaks of the disease were identified according to the real-time RT-PCR detection. Descriptive analysis was conducted to understand the type/subtype of HFMD virus and time, area, place and extent of the outbreaks. Logistic regression was used to explore the influencing factors. Results: From 2012 to 2015, a total of 1 425 HFMD epidemics, including 1 314 clusters and 111 outbreaks were reported. Two incidence peaks were observed each year, between March and June, as well as between September and December, accounting for 58.18% (829/1 425), 33.68% (480/1 425), respectively. Most HFMD clusters and outbreaks were reported in Wuxi city, accounting for 59.30% (845/1 425) of the total. Most HFMD clusters and outbreaks happened in kindergartens, accounting for 68.63% (978/1 425) of the total. A total of 931 HFMD clusters and outbreaks were confirmed under laboratory findings. The main pathogens were Entervirus type 71 (EV71) in 2013 and Coxsackie A16 (Cox A16) in 2015, respectively, while both EV71 and Cox A16 were predominant in 2012 and 2014. With multivariate backward conditional regression, surrounding environment was identified as important risk factor associated with the attack rate. Health condition of the environment was quite good, with low attack rates (middle vs. bad: OR=0.150, 95% CI: 0.034-0.667; good vs. bad: OR=0.072, 95%CI: 0.016-0.317). Time between the onset of index patient and the reporting of HFMD clusters or outbreaks was important in the control program of HFMD epidemics (4-7 d vs. 1-3 d: OR=3.452, 95%CI: 2.293-5.198; 8 d vs. 1-3 d: OR=12.108, 95%CI: 7.767-18.763). Conclusions: The clusters and outbreaks of HFMD happened in Jiangsu province showed an obvious feature of seasonality. The predominant types or subtypes of the virus varied in different years. Kindergartens were the hard-hit places of HFMD clusters and outbreaks. Timely report of the disease appeared the key point regarding the control of HFMD clusters and outbreaks.

Inactivation of Cronobacter sakazakii in reconstituted infant formula by combination of thymoquinone and mild heat

AIMS

The objective of this study was to determine the combined effect of thymoquinone (TQ) and mild heat on Cronobacter sakazakii in reconstituted infant formula.

METHODS AND RESULTS

Reconstituted infant formula samples inoculated with a mixture of four C. sakazakii strains (approx. 6·5 log CFU ml(-1) ) were prepared with various concentrations of TQ (0, 5, 10, 20 and 30 mmol l(-1) ) and were heated to 45, 50 and 55°C for 0, 10, 20, 30, 60 and 120 min, and the surviving populations of C. sakazakii at each sampling time were enumerated. To elucidate the mode of action of TQ, membrane integrity and changes in cell morphology were examined by LIVE/DEAD(®) BacLight(™) bacterial viability kit and field emission scanning electron microscope respectively. TQ at 30 mmol l(-1) reduced the pathogen to undetectable level in between 60 and 120 min at 45°C, 60 min at 50°C and 10 min at 55°C respectively.

CONCLUSIONS

Our results demonstrated that the combined treatments significantly reduced (P < 0·05) the population of C. sakazakii, compared to the control. Cronobacter sakazakii numbers were reduced much more rapidly with higher temperatures and increased concentrations of TQ. And combined treatment inactivated pathogen partly by causing cell membrane disruption.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings suggested that TQ, together with mild heat, may have potential application in infant formula to control C. sakazakii before consumption and therefore is a possible way to prevent infections associated with C. sakazakii in infant formula.

UBE2S, a novel substrate of Akt1, associates with Ku70 and regulates DNA repair and glioblastoma multiforme resistance to chemotherapy

Glioblastoma multiforme (GBM) is the most common primary malignant brain cancer in adults. However, the molecular events underlying carcinogenesis and their interplay remain elusive. Here, we report that the stability of Ubiquitin-conjugating enzyme E2S (UBE2S) is regulated by the PTEN/Akt pathway and that its degradation depends on the ubiquitin-proteasome system. Mechanistically, Akt1 physically interacted with and phosphorylated UBE2S at Thr 152, enhancing its stability by inhibiting proteasomal degradation. Additionally, accumulated UBE2S was found to be associated with the components of the non-homologous end-joining (NHEJ) complex and participated in the NHEJ-mediated DNA repair process. The association of Ku70 with UBE2S was enhanced, and the complex was recruited to double-stranded break (DSB) sites in response to etoposide treatment. Furthermore, knockdown of UBE2S expression inhibited NHEJ-mediated DSB repair and rendered glioblastoma cells more sensitive to chemotherapy. Overall, our findings provide a novel drug target that may serve as the rationale for the development of a new therapeutic approach.

A clock network for geodesy and fundamental science

Leveraging the unrivalled performance of optical clocks as key tools for geo-science, for astronomy and for fundamental physics beyond the standard model requires comparing the frequency of distant optical clocks faithfully. Here, we report on the comparison and agreement of two strontium optical clocks at an uncertainty of 5 × 10⁻¹⁷ via a newly established phase-coherent frequency link connecting Paris and Braunschweig using 1,415 km of telecom fibre. The remote comparison is limited only by the instability and uncertainty of the strontium lattice clocks themselves, with negligible contributions from the optical frequency transfer. A fractional precision of 3 × 10⁻¹⁷ is reached after only 1,000 s averaging time, which is already 10 times better and more than four orders of magnitude faster than any previous long-distance clock comparison. The capability of performing high resolution international clock comparisons paves the way for a redefinition of the unit of time and an all-optical dissemination of the SI-second.

Comparing the frequency of two distant optical clocks will enable sensitive tests of fundamental physics. Here, the authors compare two strontium optical-lattice clocks 690 kilometres apart to a degree of accuracy that is limited only by the uncertainty of the individual clocks themselves.

Immunological mechanisms involved in probiotic-mediated protection against Citrobacter rodentium-induced colitis

Inflammatory bowel disease is a group of chronic, incurable inflammatory disorders of the gastrointestinal tract that cause severe diarrhoea, intestinal inflammation, pain, fatigue and weight loss. In this study, we first developed a model of Citrobacter rodentium-induced colitis and then evaluated the protective effects of selected probiotics on inflammation. The results showed that administration of a combination of probiotics including Lactobacillus rhamnosus ATCC 53103, Lactobacillus acidophilus ATCC 4356 and Lactobacillus plantarum A significantly increased the production of CD11c+ dendritic cells in the spleen (3.62% vs phosphate buffered saline (PBS)-treated control, P<0.01) and mesenteric lymph nodes (MLNs). In addition, the presence of probiotics significantly up-regulated the development of CD4+/CD25+/Foxp3+ regulatory T cells in MLNs by approximately 2.07% compared to the effect observed in the PBS-treated control (P<0.01) and down-regulated the expression of inflammatory cytokines, including interleukin-17, tumour necrosis factor-α and interferon-γ, by 0.11, 0.11 and 0.15%, respectively, compared to the effect observed in the PBS-treated control (P<0.01).These effects conferred protection against colitis, as shown by histopathological analyses.

Nodular melanoma in trophic ulceration of a leprosy patient: a case study

Non-healing chronic trophic ulceration is very common in leprosy patients. Marjolin's ulcer consists of the malignant transformation of a chronic ulcerative lesion. Nodular melanoma developing from Marjolin's ulcer, caused by a trophic ulceration of a leprosy patient, is very rare with only a few cases reported in the literature. Due to the disguised presentation of these malignancies within trophic ulceration lesions in leprosy, neoplastic transformation is frequently overlooked, leading to misdiagnosed and delayed treatment. This paper reports a case of an 83-year-old man with lepromatous leprosy and chronic ulceration on the foot for 22 years. Over a period of 2 months, the ulcer enlarged, turned black, and became more painful. The patient underwent regional excision and immunotherapy after the diagnosis of malignant nodular melanoma. After 9 months follow-up, no metastasis was found.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

Amino acid, phosphorus, and energy digestibility of Aspergillus niger fermented rapeseed meal fed to growing pigs

Fermented rapeseed meal (FRSM) contains greater levels of protein and less glucosinolates, NDF, and phytic acid than rapeseed meal (RSM) and might be an attractive feedstuff for swine, but its nutritional value has been poorly characterized. The aim of this study was to evaluate the nutritional value of RSM fermented by for growing pigs. In Exp. 1, 6 barrows (21.20 ± 1.47 kg initial BW) fitted with a T-cannula in the distal ileum were allotted to a repeated 3 × 3 Latin square with 3 diets and 3 periods per square to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA. A N-free diet and 2 diets containing RSM or FRSM as the only source of AA were formulated. Results indicated that there was no difference in AID and SID of CP and most AA between FRSM and RSM. However, the AID of 2 indispensable AA (Lys and Met) and 3 dispensable AA (Asp, Gly, and Tyr) were greater (P < 0.05) for FRSM than for RSM. The SID of only 2 dispensable AA (Gly and Tyr) were greater (P < 0.05) for FRSM than for RSM. In Exp. 2, 16 barrows (32.57 ± 2.67 kg initial BW) were allotted to 2 diets formulated to contain RSM or FRSM as the sole source of P to determine the apparent total tract digestibility (ATTD) of P. The ATTD and standardized total tract digestibility (STTD) of P in FRSM were 72.10 and 77.31%, respectively. These values were greater (P < 0.01) than in RSM (34.79 and 41.34%, respectively). In Exp. 3, 24 growing barrows (32.23 ± 1.33 kg initial BW) were fed 3 diets with 8 replicate pigs per diet to measure concentration of DE and ME of FRSM. A corn diet consisting of 98.40% corn was formulated and 2 additional diets were formulated by mixing corn with 35% RSM or FRSM. The DE and ME in FRSM (2,887 and 2,650 kcal/kg of DM, respectively) were greater (P < 0.05) than those in RSM (2,609 and 2,328 kcal/kg of DM, respectively). In summary, solid-state fermentation of RSM by has a greater nutritional value than RSM and is a promising alternative high-quality protein source.

Ethanol adaptation induces direct protection and cross-protection against freezing stress in Salmonella enterica serovar Enteritidis

AIMS

Salmonella enterica serovar Enteritidis (Salm. Enteritidis) encounters mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adaptation on stress tolerance of Salm. Enteritidis.

METHODS AND RESULTS

Salmonella Enteritidis was subjected to different ethanol adaptation treatments (2·5-10% ethanol for 1 h). Cellular morphology and tolerance to subsequent environmental stresses (15% ethanol, -20°C, 4°C, 50°C and 10% NaCl) were evaluated. It was found that 10% was the maximum ethanol concentration that allowed growth of the target bacteria. Ethanol adaptation did not cause cell-surface damage in Salm. Enteritidis as revealed by membrane permeability measurements and electron micrograph analysis. Salmonella Enteritidis adapted with 2·5-10% ethanol displayed an enhanced resistance to a 15%-ethanol challenge compared with an unchallenged control. The maximum ethanol resistance was observed when ethanol concentration used for ethanol adaptation was increased to 5·0%. Additionally, pre-adaptation to 5·0% ethanol cross-protected Salm. Enteritidis against -20°C, but not against 4°C, 50°C or 10% NaCl.

CONCLUSIONS

Ethanol adaptation provided Salm. Enteritidis direct protection from a high level ethanol challenge and cross-protection from freezing, but not other stresses tested (low temperature, high salinity or high temperature).

SIGNIFICANCE AND IMPACT OF THE STUDY

The results are valuable in developing adequate and efficient control measures for Salm. Enteritidis in foods.

Bifunctional alloys for the electroreduction of CO2and CO

We use density functional theory to study the reduction of CO₂and CO to hydrocarbons through a formyl pathway on (111) and (211) facets of L1₂alloys with an A₃B composition.