Towards an actionable One Health approach

BACKGROUND

Despite the increasing focus on strengthening One Health capacity building on global level, challenges remain in devising and implementing real-world interventions particularly in the Asia-Pacific region. Recognizing these gaps, the One Health Action Commission (OHAC) was established as an academic community for One Health action with an emphasis on research agenda setting to identify actions for highest impact.

MAIN TEXT

This viewpoint describes the agenda of, and motivation for, the recently formed OHAC. Recognizing the urgent need for evidence to support the formulation of necessary action plans, OHAC advocates the adoption of both bottom-up and top-down approaches to identify the current gaps in combating zoonoses, antimicrobial resistance, addressing food safety, and to enhance capacity building for context-sensitive One Health implementation.

CONCLUSIONS

By promoting broader engagement and connection of multidisciplinary stakeholders, OHAC envisions a collaborative global platform for the generation of innovative One Health knowledge, distilled practical experience and actionable policy advice, guided by strong ethical principles of One Health.

China's application of the One Health approach in addressing public health threats at the human-animal-environment interface: Advances and challenges

Background

Due to emerging issues such as global climate change and zoonotic disease pandemics, the One Health approach has gained more attention since the turn of the 21st century. Although One Health thinking has deep roots and early applications in Chinese history, significant gaps exist in China's real-world implementation at the complex interface of the human-animal-environment.

Methods

We abstracted the data from the global One Health index study and analysed China's performance in selected fields based on Structure-Process-Outcome model. By comparing China to the Belt & Road and G20 countries, the advances and gaps in China's One Health performance were determined and analysed.

Findings

For the selected scientific fields, China generally performs better in ensuring food security and controlling antimicrobial resistance and worse in addressing climate change. Based on the SPO model, the "structure" indicators have the highest proportion (80.00%) of high ranking and the "outcome" indicators have the highest proportion (20.00%) of low ranking. When compared with Belt and Road countries, China scores above the median in almost all indicators (16 out of 18) under the selected scientific fields. When compared with G20 countries, China ranks highest in food security (scores 72.56 and ranks 6th), and lowest in climate change (48.74, 11th).

Conclusion

Our results indicate that while China has made significant efforts to enhance the application of the One Health approach in national policies, it still faces challenges in translating policies into practical measures. It is recommended that a holistic One Health action framework be established for China in accordance with diverse social and cultural contexts, with a particular emphasis on overcoming data barriers and mobilizing stakeholders both domestically and globally. Implementation mechanisms, with clarified stakeholder responsibilities and incentives, should be improved along with top-level design.

Phenotypic and genetic characterization of hypervirulent Klebsiella pneumoniae in patients with liver abscess and ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) and pyogenic liver abscess (PLA) due to Klebsiella pneumoniae infection can trigger life-threatening malignant consequences, however, there are few studies on the strain-associated clinical pathogenic mechanisms between VAP and PLA. A total of 266 patients consist of 129 VAP and 137 PLA were included for analysis in this study. We conducted a comprehensive survey for the two groups of K. pneumoniae isolates, including phenotypic experiments, clinical epidemiology, genomic analysis, and instrumental analysis, i.e., to obtain the genomic differential profile of K. pneumoniae strains responsible for two distinct infection outcomes. We found that PLA group had a propensity for specific underlying diseases, especially diabetes and cholelithiasis. The resistance level of VAP was significantly higher than that of PLA (78.57% vs. 36%, P < 0.001), while the virulence results were opposite. There were also some differences in key signaling pathways of biochemical processes between the two groups. The combination of iucA, rmpA, hypermucoviscous phenotype, and ST23 presented in K. pneumoniae infection is more important and highly prudent for timely treatment. The present study may contribute a benchmark for the K. pneumoniae clinical screening, epidemiological surveillance, and effective therapeutic strategies.

Assessing food security performance from the One Health concept: an evaluation tool based on the Global One Health Index

BACKGROUND

Food systems instantiate the complex interdependencies across humans, physical environments, and other organisms. Applying One Health approaches for agri-food system transformation, which adopts integrated and unifying approaches to optimize the overall health of humans, animals, plants, and environments, is crucial to enhance the sustainability of food systems. This study develops a potential assessment tool, named the global One Health index-Food Security (GOHI-FS), aiming to evaluate food security performance across countries/territories from One Health perspective and identify relevant gaps that need to be improved for sustainable food systems.

METHODS

We comprehensively reviewed existing frameworks and elements of food security. The indicator framework of GOHI-FS was conceptualized following the structure-process-outcome model and confirmed by expert advisory. Publicly available data in 2020 was collected for each indicator. The weighting strategy was determined by the Fuzzy Analytical Hierarchy Process. The data for each indicator was normalized and aggregated by weighted arithmetic mean. Linear regressions were performed to evaluate the associations of GOHI-FS with health and social-economic indicators.

RESULTS

The GOHI-FS includes 5 first-level indicators, 19 second-level indicators and 45 third-level indicators. There were 146 countries/territories enrolled for evaluation. The highest average score of first-level indicators was Nutrition (69.8) and the lowest was Government Support and Response (31.3). There was regional heterogeneity of GOHI-FS scores. Higher median scores with interquartile range (IQR) were shown in North America (median: 76.1, IQR: 75.5-76.7), followed by Europe and Central Asia (median: 66.9, IQR: 60.1-74.3), East Asia and the Pacific (median: 60.6, IQR: 55.5-68.7), Latin America and the Caribbean (median: 60.2, IQR: 57.8-65.0), Middle East and North Africa (median: 56.6, IQR: 52.0-62.8), South Asia (median: 51.1, IQR: 46.7-53.8), and sub-Saharan Africa (median: 41.4, IQR: 37.2-46.5). We also found significant associations between GOHI-FS and GDP per capita, socio-demographic index, health expenditure and life expectancy.

CONCLUSIONS

GOHI-FS is a potential assessment tool to understand the gaps in food security across countries/territories under the One Health concept. The pilot findings suggest notable gaps for sub-Saharan Africa in numerous aspects. Broad actions are needed globally to promote government support and response for food security.

Tackling global health security by building an academic community for One Health action

BACKGROUND

One Health approach is crucial to tackling complex global public health threats at the interface of humans, animals, and the environment. As outlined in the One Health Joint Plan of Action, the international One Health community includes stakeholders from different sectors. Supported by the Bill & Melinda Gates Foundation, an academic community for One Health action has been proposed with the aim of promoting the understanding and real-world implementation of One Health approach and contribution towards the Sustainable Development Goals for a healthy planet.

MAIN TEXT

The proposed academic community would contribute to generating high-quality scientific evidence, distilling local experiences as well as fostering an interconnected One Health culture and mindset, among various stakeholders on different levels and in all sectors. The major scope of the community covers One Health governance, zoonotic diseases, food security, antimicrobial resistance, and climate change along with the research agenda to be developed. The academic community will be supported by two committees, including a strategic consultancy committee and a scientific steering committee, composed of influential scientists selected from the One Health information database. A workplan containing activities under six objectives is proposed to provide research support, strengthen local capacity, and enhance global participation.

CONCLUSIONS

The proposed academic community for One Health action is a crucial step towards enhancing communication, coordination, collaboration, and capacity building for the implementation of One Health. By bringing eminent global experts together, the academic community possesses the potential to generate scientific evidence and provide advice to local governments and international organizations, enabling the pursuit of common goals, collaborative policies, and solutions to misaligned interests.

Assessment of performance for a key indicator of One Health: evidence based on One Health index for zoonoses in Sub-Saharan Africa

BACKGROUND

Zoonoses are public health threats that cause severe damage worldwide. Zoonoses constitute a key indicator of One Health (OH) and the OH approach is being applied for zoonosis control programmes of zoonotic diseases. In a very recent study, we developed an evaluation system for OH performance through the global OH index (GOHI). This study applied the GOHI to evaluate OH performance for zoonoses in sub-Saharan Africa.

METHODS

The framework for the OH index on zoonoses (OHIZ) was constructed including five indicators, 15 subindicators and 28 datasets. Publicly available data were referenced to generate the OHIZ database which included both qualitative and quantitative indicators for all sub-Sahara African countries (n = 48). The GOHI algorithm was used to estimate scores for OHIZ. Indicator weights were calculated by adopting the fuzzy analytical hierarchy process.

RESULTS

Overall, five indicators associated with weights were generated as follows: source of infection (23.70%), route of transmission (25.31%), targeted population (19.09%), capacity building (16.77%), and outcomes/case studies (15.13%). Following the indicators, a total of 37 sub-Sahara African countries aligned with OHIZ validation, while 11 territories were excluded for unfit or missing data. The OHIZ average score of sub-Saharan Africa was estimated at 53.67/100. The highest score was 71.99 from South Africa, while the lowest score was 40.51 from Benin. It is also worth mentioning that Sub-Sahara African countries had high performance in many subindicators associated with zoonoses, e.g., surveillance and response, vector and reservoir interventions, and natural protected areas, which suggests that this region had a certain capacity in control and prevention or responses to zoonotic events.

CONCLUSIONS

This study reveals that it is possible to perform OH evaluation for zoonoses in sub-Saharan Africa by OHIZ. Findings from this study provide preliminary research information in advancing knowledge of the evidenced risks to strengthen strategies for effective control of zoonoses and to support the prevention of zoonotic events.

Clonorchis sinensis infection modulates key cytokines for essential immune response impacted by sex

Infection with helminths can modulate the host immune response, which ultimately shape morbidity and mortality of the associated diseases. We studied key cytokines for essential immune response in sera from 229 southeastern China individuals infected with Clonorchis sinensis and 60 individuals without C. sinensis infection, and measured serum specific IgG and IgE against worms in these people. Individuals infected with C. sinensis had significantly higher antigen-specific IgG and IgE levels, which were positively correlated with egg counts in feces. However, less enhancement of IgE antibody was observed in females when compared to males with similar infection levels. C. sinensis infection caused diminished Th1 cytokines (IL-1β, IL-2, IL-12p70, IFN-γ and TNF-α), Th2 cytokine (IL-4), as well as Th17 cytokine (IL-17A) in sera, which showed decreasing trend by infection intensity. Notably, these phenotypes were more significant in females than those in males. Although C. sinensis infection is associated with the development of hepatobiliary diseases, there was no significant correlation between the dampened cytokine profiles and the hepatobiliary morbidities. Our study indicates C. sinensis infection is strongly related to the immune suppression in human. Sex differences shape the immune milieus of clonorchiasis. This study provides a better understanding of how worms affect immune responses and cause a long-term immune alternation in humans with C. sinensis infection.

Key immunity characteristics of diverse stages of brucellosis in rural population from Inner Mongolia, China

Background

Brucellosis poses a serious threat to human and animal health, particularly in developing countries such as China. The Inner Mongolia Autonomous Region is one of the most severely brucellosis-endemic provinces in China. Currently, the host immune responses functioning to control Brucella infection and development remain poorly understood. The aim of this study is to further clarify the key immunity characteristics of diverse stages of brucellosis in Inner Mongolia.

Methods

We collected a total of 733 blood samples from acute (n = 137), chronic (n = 316), inapparent (n = 35), recovery (n = 99), and healthy (n = 146) groups from the rural community of Inner Mongolia between 2014 and 2015. The proportions of CD4⁺, CD8⁺, Th1, Th2, and Th17 T cells in peripheral blood and the expression of TLR2 and TLR4 in lymphocytes, monocytes and granulocytes were examined using flow cytometry analysis. The differences among the five groups were compared using one-way ANOVA and the Kruskal–Wallis method, respectively.

Results

Our results revealed that the proportions of CD4⁺ and CD8⁺ T cells were significantly different among the acute, chronic, recovery, and healthy control groups (P < 0.05), with lower proportions of CD4⁺ T cells and a higher proportion of CD8⁺ T cells in the acute, chronic, and recovery groups. The proportion of Th1 cells in the acute, chronic, and inapparent groups was higher than that in the healthy and recovery groups; however, there was no significant difference between patients and healthy individuals (P > 0.05). The proportion of Th2 lymphocytes was significantly higher in the acute and healthy groups than in the inapparent group (P < 0.05). The proportion of Th17 cells in the acute group was significantly higher than that in the healthy control, chronic, and inapparent groups (P < 0.05). Finally, the highest expression of TLR4 in lymphocytes, monocytes and granulocytes was observed in the recovery group, and this was followed by the acute, chronic, healthy control, and inapparent groups. There was a significant difference between the recovery group and the other groups, except for the acute group (P < 0.05). Moreover, a correlation in TLR4 expression was observed in lymphocytes, monocytes and granulocytes among the five groups (r > 0.5), except for the inapparent group between lymphocytes and granulocytes (r = 0.34).

Conclusions

Two key factors (CD8⁺ T cells and TLR4) in human immune profiles may closely correlate with the progression of brucellosis. The detailed function of TLR4 in the context of a greater number of cell types or tissues in human or animal brucellosis and in larger samples should be further explored in the future.

Graphical Abstract

Towards a global One Health index: a potential assessment tool for One Health performance

Background

A One Health approach has been increasingly mainstreamed by the international community, as it provides for holistic thinking in recognizing the close links and inter-dependence of the health of humans, animals and the environment. However, the dearth of real-world evidence has hampered application of a One Health approach in shaping policies and practice. This study proposes the development of a potential evaluation tool for One Health performance, in order to contribute to the scientific measurement of One Health approach and the identification of gaps where One Health capacity building is most urgently needed.

Methods

We describe five steps towards a global One Health index (GOHI), including (i) framework formulation; (ii) indicator selection; (iii) database building; (iv) weight determination; and (v) GOHI scores calculation. A cell-like framework for GOHI is proposed, which comprises an external drivers index (EDI), an intrinsic drivers index (IDI) and a core drivers index (CDI). We construct the indicator scheme for GOHI based on this framework after multiple rounds of panel discussions with our expert advisory committee. A fuzzy analytical hierarchy process is adopted to determine the weights for each of the indicators.

Results

The weighted indicator scheme of GOHI comprises three first-level indicators, 13 second-level indicators, and 57 third-level indicators. According to the pilot analysis based on the data from more than 200 countries/territories the GOHI scores overall are far from ideal (the highest score of 65.0 out of a maximum score of 100), and we found considerable variations among different countries/territories (31.8–65.0). The results from the pilot analysis are consistent with the results from a literature review, which suggests that a GOHI as a potential tool for the assessment of One Health performance might be feasible.

Conclusions

GOHI—subject to rigorous validation—would represent the world’s first evaluation tool that constructs the conceptual framework from a holistic perspective of One Health. Future application of GOHI might promote a common understanding of a strong One Health approach and provide reference for promoting effective measures to strengthen One Health capacity building. With further adaptations under various scenarios, GOHI, along with its technical protocols and databases, will be updated regularly to address current technical limitations, and capture new knowledge.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00979-9.

[One Health: Re-thinking of zoonoses control]

Under the dual pressure of emerging zoonoses and the difficulty in eliminating conventional zoonoses, many uncertainties in global control of infectious diseases are challenging the achievement of sustainable development goals set by the United Nations General Assembly. One Health, developed on the basis of understanding the relationship between human diseases and animal diseases, is conducive to the prevention and control of zoonoses. The connotation of "One Health" is mainly explained by three aspects, namely the systems thinking mode of "unity of environment and man", the practice guidance of "multi-sectoral concert" and the economic evaluation strategy of "cost-effectiveness analysis". One Health approach has been successfully applied in the control of major infectious diseases in China, such as schistosomiasis, leading to remarkable achievements; however, there are still multiple challenges. This review proposes that much attention should be paid to top-level design, the difference between emerging zoonoses and conventional zoonoses, and the dynamic process of One Health governance during the development and application of One Health.

[Safety evaluation of hyperthermic intraperitoneal chemotherapy in patients with local advanced gastric cancer after radical resection for prevention of peritoneal metastasis]

Objective: Patients with advanced gastric cancer have a poor prognosis and a possibility of peritoneal metastasis even if receiving gastrectomy. Hyperthermic intraperitoneal chemotherapy (HIPEC) can effectively kill free cancer cells or small lesions in the abdominal cavity. At present, preventive HIPEC still lacks safety evaluation in patients with locally advanced gastric cancer. This study aims to explore the safety of radical resection combined with HIPEC in patients with locally advanced gastric cancer. Methods: A descriptive case series study was carried out. Clinicopathological data of 130 patients with locally advanced gastric cancer who underwent radical resection + HIPEC at the Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2020 to February 2021 were retrospectively analyzed. Inclusion criteria: (1) locally advanced gastric adenocarcinoma confirmed by postoperative pathology; (2) no distant metastasis was found before surgery; (3) radical resection; (4) at least one HIPEC treatment was performed. Exclusion criteria: (1) incomplete clinicopathological data; (2) tumor metastasis was found during operation; (3) concomitant with other tumors. HIPEC method: all the patients received the first HIPEC immediately after D2 radical resection, and returned to the ward after waking up from anesthesia; the second and the third HIPEC were carried out according to the patient's postoperative recovery and tolerance; interval between two HIPEC treatments was 48 h. Observation indicators: (1) basic information, including gender, age, body mass index, etc.; (2) treatment status; (3) perioperative adverse events: based on the standard of common adverse events published by the US Department of Health and Public Health (CTCAE 5.0), the adverse events of grade 2 and above during the treatment period were recorded, including hypoalbuminemia, bone marrow cell reduction, wound complications, abdominal infection, lung infection, gastroparesis, anemia, postoperative bleeding, anastomotic leakage, intestinal obstruction, pleural effusion, abdominal distension, impaired liver function, and finally a senior professional title chief physician reviewed the above adverse events and made a safety evaluation of the patient; (4) association between times of HIPEC treatment and adverse events in perioperative period; (5) analysis of risk factors for adverse events in perioperative period. Results: Among the 130 patients, 79 were males and 51 were females with a median age of 59 (54, 66) years and an average body mass index of (23.9±7.4) kg/m(2). The tumor size was (5.4±3.0) cm and 100 patients (76.9%) had nerve invasion. All the 130 patients received radical resection + HIPEC and 125 (96.2%) patients underwent laparoscopic surgery. The mean operative time was (345.6±52.3) min and intraoperative blood loss was (82.0±36.5) ml. One HIPEC treatment was performed in 54 patients (41.5%), 2 HIPEC treatments were in 57 (43.8%), and 3 HIPEC treatments were in 19 (14.6%). The average postoperative hospital stay was (13.1±7.5) d. A total of 57 patients (43.8%) had 71 cases of postoperative complications of different degrees. Among them, the incidence of hypoalbuminemia was 22.3% (29/130), and the grade 2 and above anemia was 15.4% (20/130), lung infection was 3.8% (5/130), bone marrow cell suppression was 3.7% (4/130), abdominal cavity infection was 2.3% (3/130), and liver damage was 2.3% (3/130), wound complications was 1.5% (2/130), abdominal distension was 1.5% (2/130), anastomotic leakage was 0.8% (1/130), gastroparesis was 0.8% (1/130) and intestinal obstruction was 0.8% (1/130), etc. These adverse events were all improved by conservative treatments. There were no statistically significant differences in the incidence of adverse events during the perioperative period among patients undergoing 1, 2, and 3 times of HIPEC treatments (all P>0.05). Univariate and multivariate logistic analyses showed that age > 60 years (OR: 2.346, 95%CI: 1.069-5.150, P=0.034) and neurological invasion (OR: 2.992, 95%CI: 1.050-8.523, P=0.040) were independent risk factors for adverse events in locally advanced gastric cancer patients undergoing radical resection+HIPEC (both P<0.05). Conclusions: Radical surgery + HIPEC does not significantly increase the incidence of perioperative complications in patients with advanced gastric cancer. The age >60 years and nerve invasion are independent risk factors for adverse events in these patients.

A Molecular Investigation of Malaria Infections From High-Transmission Areas of Southern Togo Reveals Different Species of Plasmodium Parasites

Malaria particularly burdens people in poor and neglected settings across the tropics of Africa. Meanwhile, a large proportion of the Togo population have poor understanding of malaria epidemiology and parasites. This study carried out a molecular survey of malaria cases in southern Togo during 2017–2019. We estimated Plasmodium species infection rates and microscopic examination compliance with nested PCR results. Sensitivity and specificity analyses were performed in conjunction with predictive values. Also, phylogenetic characterization of species of malaria parasites was assessed. Plasmodium genus-specific nested PCR identified 565 positive cases including 536/611 (87.8%) confirmed cases from the microscopy-positive group and 29/199 (14.6%) diagnosed malaria cases from the microscopy-negative group. Our findings revealed a disease prevalence (69.8%) higher than that reported (25.5–55.1%) for the country. The diagnostic test had 94.9% sensitivity and 69.4% specificity, i.e., it missed 120 of the people who had malaria and about one-third of the people tested positive for the disease, which they did not have, respectively. In conjunction, the test showed 87.7% positive predictive value and 85.4% negative predictive value, which, from a clinical perspective, indicates the chance that a person with a positive diagnostic test truly has the disease and the probability that a person with a negative test does not have the disease, respectively. Further species-specific nested PCR followed by analysis of gene sequences confirmed species of malaria parasites and indicated infection rates for Plasmodium falciparum (Pf), 95.5% (540/565); P. ovale (Po), 0.5% (3/565); and P. malariae (Pm), 0.4% (2/565). In addition, 20 cases were coinfection cases of Pf-Po (15/565) and Pf-Pm (5/565). This study publicly reports, for the first time, a molecular survey of malaria cases in Togo and reveals the presence of other malaria parasites (Po and Pm) other than Pf. These findings might provide answers to some basic questions on the malaria scenario and, knowledge gained could help with intervention deployment for effective malaria control in Togo.

[Comparison of short-term and long-term outcomes between thoracoscopic pneumonectomy and open pneumonectomy for non-small cell lung cancer: a study based on propensity score matching]

Objective: To compare the short-term and long-term results of thoracoscopic and open pneumonectomy for non-small cell lung cancer. Methods: The clinical data of patients with non-small cell lung cancer who underwent pneumonectomy in the Department of Thoracic Surgery, Qingdao University Hospital from January 2008 to December 2016 were collected. Totally 142 patients (55 in the thoracoscopic group and 87 in the open group) were included in the study. A total of 29 pairs of patients were successfully matched by propensity score matching (PSM). Perioperative outcomes and overall survival were compared between the two groups using t test, χ(2) test, Kaplan-Meier curve and Log-rank test, respectively. Results: Camparion with open group, the thoracoscopic group had longer operative time ((209.7±70.2) minutes vs. (171.3±43.5) minutes, t=2.50, P=0.02), more mediastinal lymph node dissection (M(Q(R)): 17(9) vs. 11(10), W=388, P=0.02) and shorter postoperative hospital stay (7.0(3.5) vs. 9.0(3.0), W=285, P=0.03). There was no significant difference in estimated blood loss, postoperative drainage time, dissected lymph node number, dissected lymph node station and perioperative complications. After PSM, there were no signifificant differences found in 3-year survival (71.4% vs. 48.1%, P=0.10) and 3-year disease-free survival (67.4% vs. 47.2%, P=0.13) between the two groups. Conclusion: Thoracoscopic pneumonectomy is safe and feasible for the treatment of non-small cell lung cancer with more mediastinal lymph node dissection and accelerating recovery, and equivalent long-term prognosis when compared with open approach.

PRL2 serves as a negative regulator in cell adaptation to oxidative stress

High levels of ROS cause oxidative stress, which plays a critical role in cell death. As a ROS effector protein, PRL2 senses ROS and controls phagocyte bactericidal activity during infection. Here we report PRL2 regulates oxidative stress induced cell death. PRL2 senses oxidative stress via highly reactive cysteine residues at 46 and 101. The oxidation of PRL2 causes protein degradation and supports pro-survival PDK1/AKT signal which in turn to protect cells against oxidative stress. As a result, PRL2 levels have a high correlation with oxidative stress induced cell death. In vivo experiments showed PRL2 deficient cells survive better in inflammatory oxidative environment and resist to ionizing radiation. Our finding suggests PRL2 serves as a negative regulator in cell adaptation to oxidative stress. Therefore, PRL2 could be targeted to modulate cell viability in inflammation or irradiation associated therapy.

Genomic Characterization Provides New Insights for Detailed Phage- Resistant Mechanism for Brucella abortus

As the causative agent of cattle brucellosis, Brucella abortus commonly exhibits smooth phenotype (by virtue of colony morphology) that is characteristically sensitive to specific Brucella phages, playing until recently a major role in taxonomical classification of the Brucella species by the phage typing approach. We previously reported the discrepancy between traditional phenotypic typing and MLVA results of a smooth phage-resistant (SPR) strain Bab8416 isolated from a 45-year-old custodial worker with brucellosis in a cattle farm. Here, we performed whole genome sequencing and further obtained a complete genome sequence of strain Bab8416 by a combination of multiple NGS technologies and routine PCR sequencing. The detailed genetic differences between B. abortus SPR Bab8416 and large smooth phage-sensitive (SPS) strains were investigated in a comprehensively comparative genomic study. The large indels between B. abortus SPS strains and Bab8416 showed possible divergence between two evolutionary branches at a far phylogenetic node. Compared to B. abortus SPS strain 9-941 (Bab9-941), the specific re-arrangement event in Bab8416 displaying a closer linear relationship with B. melitensis 16M than other B. abortus strains resulted in the truncation of c-di-GMP synthesis, and 3 c-di-GMP-metabolizing genes, were present in Bab8416 and B. melitensis 16M, but absent in Bab9-941 and other B. abortus strains, indicating potential SPR-associated key determinants and novel molecular mechanisms. Moreover, despite almost completely intact smooth LPS related genes, only one mutated OmpA family protein of Bab8416, functionally related to flagellar and efflux pump, was newly identified. Several point mutations were identified to be Bab8416 specific while a majority of them were verified to be B. abortus ST2 characteristic. In conclusion, our study therefore identifies new SPR-associated factors that could play a role in refining and updating Brucella taxonomic schemes and provides resources for further detailed analysis of mechanism for Brucella phage resistance.

[Changes of oral bacteria flora after wearing complete denture]

PURPOSE

This study investigateed the influence of complete denture on oral bacteria flora.

METHODS

Bateria plaque samples in oral mucosa, saliva and denture surfaces in 11 edentulous patients were collected, then the 16S rRNA gene clone libraries were constructed. Pyrosequencing was used to analyze the 16S rRNA gene V3~V4 regions, oral bacteria flora were classified and identified.

RESULTS

There were 64800 sequences in complete denture-wearing subjects, Streptococcus mitis, Gemella haemolysans, Rothia mucilaginosa, Porphyromonas sp, Neisseria zoodegmatis, Granulicatella elegans, Acinetobacter baumannii, Pseudomonas citrinum, Granulicatella adiacens and Fusobacterium canifelinum were the predominant species (37416 sequences). The species of denture tissue surface were similar to these of buccal vestibule after wearing denture, and the species of denture smooth surface were similar to these of tongue ventrum and the floor of mouth.

CONCLUSIONS

The effect of complete denture on oral flora is still limited, and the composition of oral flora is influenced by many other factors.

Antimicrobial susceptibility and molecular epidemiology of clinical Enterobacter cloacae bloodstream isolates in Shanghai, China

BACKGROUND

Enterobacter cloacae is a major nosocomial pathogen causing bloodstream infections. We retrospectively conducted a study to assess antimicrobial susceptibility and phylogenetic relationships of E. cloacae bloodstream isolates in two tertiary university-affiliated hospitals in Shanghai, in order to facilitate managements of E. cloacae bloodstream infections and highlight some unknowns for future prevention.

METHODS

Fifty-three non-duplicate E. cloacae bloodstream isolates were consecutively collected from 2013 to 2016. Antimicrobial susceptibility was determined by disk diffusion. PCR was performed to detect extended-spectrum β-lactamase (ESBL), carbapenemase and colistin resistance (MCR-1) gene. Plasmid-mediated AmpC β-lactamase (pAmpC) genes were detected using a multiplex PCR assay targeting MIR/ACT gene (closely related to chromosomal EBC family gene) and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. eBURST was applied to analyze multi-locus sequence typing (MLST).

RESULTS

The rates of resistance to all tested antibiotics were <40%. Among 53 E. cloacae isolates, 8(15.1%) were ESBL producers, 3(5.7%) were carbapenemase producers and 18(34.0%) were pAmpC producers. ESBL producers bear significantly higher resistance to cefotaxime (100.0%), ceftazidime (100.0%), aztreonam (100.0%), piperacillin (87.5%), tetracycline (75.0%), and trimethoprim-sulfamethoxazole (62.5%) than non-producers (p<0.05). PAmpC- and non-producers both presented low resistance rates (<40%) to all antibiotics (p>0.05). SHV (6/8, 75.0%) and MIR/ACT (15/18, 83.3%) predominated in ESBL and pAmpC producers respectively. Moreover, 2 isolates co-carried TEM-1, SHV-12, IMP-26 and DHA-1. MLST analysis distinguished the 53 isolates into 51 STs and only ST414 and ST520 were assigned two isolates of each (2/53).

CONCLUSION

The antimicrobial resistance rates were low among 53 E. cloacae bloodstream isolates in the two hospitals. Multiclonality disclosed no evidence on spread of these isolates in Shanghai. The simultaneous presence of ESBL, carbapenemase and pAmpC detected in 2 isolates was firstly reported in Shanghai, which necessitated active ongoing surveillances and consistent prevention and control of E. cloacae.

Antimicrobial Resistance and Molecular Characterization of Staphylococcus aureus Causing Childhood Pneumonia in Shanghai

Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing pneumonia among children. To estimate the prevalence and molecular properties of S. aureus in children pneumonia in Shanghai, China, 107 hospitalized children with S. aureus pneumonia from two children's hospitals from January 2014 through June 2015 were studied. S. aureus isolates from the respiratory specimens were characterized by antimicrobial susceptibility, agr typing, toxin genes, multilocus sequence typing (MLST), spa, and SCCmec typing. Fifty-eight (54.2%, 58/107) were MSSA (methicillin-susceptible Staphylococcus aureus) and 49 (45.8%, 49/107) were MRSA. No isolates were found resistant to teicoplanin, sulfamethoxazole/trimethoprim, rifampicin, quinupristin/dalfopristin, linezolid, or vancomycin. However, these isolates showed high resistant rates to erythromycin, fosfomycin-trometamol and clindamycin. The agrI (87/107, 81.3%) was the most common agr allele, followed by agrIII(10/107, 9.3%), agrII(9/107, 8.4%), and agrIV(1/107, 0.9%). Six pvl-positive isolates (3 MRSA and 3 MSSA) and 7 isolates of livestock associated clone ST398 (4 MRSA, 3 MSSA) were identified. CC59 was found in 35 isolates (33 MRSA and 2 MSSA), constituting majority of MRSA (33/49, 67.35%). The dominant CC were CC59 (32.7%), CC188 (13.1%), CC7 (12.1%) and CC398 (9.3%) while t172 (16.8%), t189 (12.1%), t437 (9.3%), and t091 (9.3%) were the most common spa types. In conclusion, more particular concern should appeal to ST59-SCCmecIV-t172/t437 as it is the most common epidemic clone causing pneumonia among children in Shanghai.

A Novel Pan-Genome Reverse Vaccinology Approach Employing a Negative-Selection Strategy for Screening Surface-Exposed Antigens against leptospirosis

Reverse vaccinology (RV) has been widely used for screening of surface-exposed proteins (PSEs) of important pathogens, including outer membrane proteins (OMPs), and extracellular proteins (ECPs) as potential vaccine candidates. In this study, we applied a novel RV negative strategy and a pan-genome analysis for screening of PSEs from 17 L. interrogans strains covering 11 predominately epidemic serovars and 17 multilocus typing (MLST) sequence types (STs) worldwide. Our results showed, for instance, out of a total of 633 predicted PSEs in strain 56601, 92.8% were OMPs or ECPs (588/633). Among the 17 strains, 190 core PSEs, 913 dispensable PSEs and 861 unique PSEs were identified. Of the 190 PSEs, 121 were further predicted to be highly antigenic and thus may serve as potential vaccine candidates against leptospirosis. With the exception of LipL45, OmpL1, and LigB, the majority of the 121 PSEs were newly identified antigens. For example, hypothetical proteins BatC, LipL71, and the OmpA family proteins sharing many common features, such as surface-exposed localization, universal conservation, and eliciting strong antibody responses in patients, are regarded as the most promising vaccine antigens. Additionally, a wide array of potential virulence factors among the predicted PSEs including TonB-dependent receptor, sphingomyelinase 2, leucine-rich repeat protein, and 4 neighboring hypothetical proteins were identified as potential antigenicity, and deserve further investigation. Our results can contribute to the prediction of suitable antigens as potential vaccine candidates against leptospirosis and also provide further insights into mechanisms of leptospiral pathogenicity. In addition, our novel negative-screening strategy combined with pan-genome analysis can be a routine RV method applied to numerous other pathogens.

Molecular Epidemiology of Staphylococcus aureus among Patients with Skin and Soft Tissue Infections in Two Chinese Hospitals

Background:

Staphylococcus aureus is one of the predominant causes of skin and soft tissue infections (SSTIs), but limited data were available regarding the characterization of S. aureus from SSTIs patients in Jiangsu Province in China. We aimed to investigate the molecular epidemiology of S. aureus among SSTIs patients in two hospitals of Jiangsu Province.

Methods:

Sixty-two patients with SSTIs from two Chinese hospitals in Jiangsu Province were enrolled in this study, and 62 S. aureus isolates were collected from February 2014 to January 2015. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, Staphylococcus protein A gene type, accessory gene regulator (agr) group, and Staphylococcal cassette chromosome mec type.

Results:

Sixteen (25.8%) methicillin-resistant S. aureus (MRSA) isolates were detected, and there was no isolate found resistant to vancomycin, teicoplanin, sulfamethoxazole-trimethoprim, and linezolid. The sei was the toxin gene most frequently found, and no lukS/F-PV-positive isolates were detected among the SSTIs’ patients. Molecular analysis revealed that ST398 (10/62, 16.1%; 2 MRSA and 8 methicillin-susceptible S. aureus) to be the dominant clone, followed by ST5 (8/62, 12.9%) and ST7 (8/62, 12.9%).

Conclusions:

The livestock ST398 was the most common clone among patients with S. aureus SSTIs in Jiangsu Province, China. Surveillance and further studies on the important livestock ST398 clone in human infections are necessarily requested.

The Resistance Phenotype and Molecular Epidemiology of Klebsiella pneumoniae in Bloodstream Infections in Shanghai, China, 2012-2015

Klebsiella pneumoniae (K.pneumoniae) is a common nosocomial pathogen causing bloodstream infections. Antibiotic susceptibility surveillance and molecular characterization will facilitate prevention and management of K. pneumoniae bloodstream infections. K. pneumoniae isolates causing bloodstream infections were consecutively collected between January 2012 and December 2015 in Shanghai. Eighty isolates (20 per year) were randomly selected and enrolled in this study. Drug susceptibility were determined by the disk diffusion method. Polymerase chain reaction (PCR) was employed to detect extended-spectrum β-lactamases (ESBLs), carbapenemases, and seven housekeeping genes of K. pneumoniae. eBURST was used for multi-locus sequence typing (MLST). More than 50% isolates were resistant to cefuroxime, ampicillin-sulbactam, and piperacillin, while carbapenems had lower resistant rates than other antibiotics. Of the 80 isolates, 22 produced ESBLs, and 14 were carbapenemase producers. In the ESBL-producing K. pneumoniae isolates, the most common ESBL genes were bla_SHV and bla_CTX-M. Thirteen carbapenemase producers harbored bla_KPC-2 and one other carried bla_NDM-5. ST11 (14/80) was the most frequent sequence type (ST), followed by ST15 (7/80) and ST29 (4/80). Our data revealed high prevalence of antibiotic resistant K. pneumoniae isolates from bloodstream infections but their genetic diversity suggested no clonal dissemination in the region. Also, one K. pneumoniae isolate harbored bla_NDM-5 in this study, which was firstly reported in Shanghai.

Reduced Staphylococcus aureus biofilm formation in the presence of chitosan-coated iron oxide nanoparticles

Staphylococcus aureus can adhere to most foreign materials and form biofilm on the surface of medical devices. Biofilm infections are difficult to resolve. The goal of this in vitro study was to explore the use of chitosan-coated nanoparticles to prevent biofilm formation. For this purpose, S. aureus was seeded in 96-well plates to incubate with chitosan-coated iron oxide nanoparticles in order to study the efficiency of biofilm formation inhibition. The biofilm bacteria count was determined using the spread plate method; biomass formation was measured using the crystal violet staining method. Confocal laser scanning microscopy and scanning electron microscopy were used to study the biofilm formation. The results showed decreased viable bacteria numbers and biomass formation when incubated with chitosan-coated iron oxide nanoparticles at all test concentrations. Confocal laser scanning microscopy showed increased dead bacteria and thinner biofilm when incubated with nanoparticles at a concentration of 500 µg/mL. Scanning electron microscopy revealed that chitosan-coated iron oxide nanoparticles inhibited biofilm formation in polystyrene plates. Future studies should be performed to study these nanoparticles for anti-infective use.

Risk factors for methicillin-resistant Staphylococcus aureus carriage among residents in 7 nursing homes in Shanghai, China

BACKGROUND

Nursing home residents are a population at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage, but few data about MRSA in this setting in Shanghai are available. The aim of this study is to determine the prevalence and risk factors for MRSA carriage in nursing home residents in Shanghai, China.

METHODS

Four hundred forty-three residents from 7 nursing homes in Shanghai, China, participated in this study; nasal and axillary swabs were obtained from these residents. Laboratory identification for S aureus and antimicrobial susceptibility testing were performed when isolated. Data, including individual resident characteristics and nursing home characteristics, were collected and analyzed.

RESULTS

Of the 443 participating residents, 99 (22.3%) and 45 (10.2%) residents were colonized by S aureus and MRSA, respectively. Previous hospitalization (odds ratio [OR], 2.564; 95% confidence interval [CI], 1.214-5.415; P = .014), presence of an invasive device (OR, 3.455; 95% CI, 1.678-7.113; P = .001), chloramphenicol therapy (OR, 7.672; 95% CI, 1.807-32.580; P = .006), and macrolides therapy (OR, 2.796; 95% CI, 1.056-7.403; P = .038) were independent risk factors for MRSA colonization. Low expenditure per month and less good sanitary condition also increased the risk for MRSA colonization.

CONCLUSIONS

Our study suggests that nursing homes are significant reservoirs for MRSA. Implementation of infection control strategies must be given high priority in nursing homes to fight the high prevalence of MRSA, and increased convenience and feasibility should also be realized with these control strategies for MRSA colonization.

Antimicrobial Resistance and Molecular Epidemiology of Escherichia coli Causing Bloodstream Infections in Three Hospitals in Shanghai, China

Escherichia coli (E. coli) is one of the most frequent and lethal causes of bloodstream infections (BSIs). We carried out a retrospective multicenter study on antimicrobial resistance and phylogenetic background of clinical E. coli isolates recovered from bloodstream in three hospitals in Shanghai. E. coli isolates causing BSIs were consecutively collected between Sept 2013 and Sept 2014. Ninety isolates randomly selected (30 from each hospital) were enrolled in the study. Antimicrobial susceptibility testing was performed by disk diffusion. PCR was used to detect antimicrobial resistance genes coding for β-lactamases (TEM, CTX-M, OXA, etc.), carbapenemases (IMP, VIM, KPC, NDM-1 and OXA-48), and phylogenetic groups. eBURST was applied for analysis of multi-locus sequence typing (MLST). The resistance rates for penicillins, second-generation cephalosporins, fluoroquinolone and tetracyclines were high (>60%). Sixty-one of the 90 (67.8%) strains enrolled produced ESBLs and no carbapenemases were found. Molecular analysis showed that CTX-M-15 (25/61), CTX-M-14 (18/61) and CTX-M-55 (9/61) were the most common ESBLs. Phylogenetic group B2 predominated (43.3%) and exhibited the highest rates of ESBLs production. ST131 (20/90) was the most common sequence type and almost assigned to phylogenetic group B2 (19/20). The following sequence types were ST405 (8/90) and ST69 (5/90). Among 61 ESBL-producers isolates, B2 (26, 42.6%) and ST131 (18, 29.5%) were also the most common phylogenetic group and sequence type. Genetic diversity showed no evidence suggesting a spread of these antimicrobial resistant isolates in the three hospitals. In order to provide more comprehensive and reliable epidemiological information for preventing further dissemination, well-designed and continuous surveillance with more hospitals participating was important.

Typing Discrepancy Between Phenotypic and Molecular Characterization Revealing an Emerging Biovar 9 Variant of Smooth Phage-Resistant B. abortus Strain 8416 in China

A newly isolated smooth colony morphology phage-resistant strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of Brucella melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO₂ requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 could not be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella sp. is subject to variation and the routine Brucella biovar typing needs further studies.

First report of two rapid-onset fatal infections caused by a newly emerging hypervirulent K. Pneumonia ST86 strain of serotype K2 in China

Here, we present the first report of one suspected dead case and two confirmed rapid-onset fatal infections caused by a newly emerging hypervirulent Klebsiella pneumoniae ST86 strain of serotype K2. The three cases occurred in a surgery ward during 2013 in Shanghai, China. A combination of multilocus sequence typing, pulsed-field gel electrophoresis, phenotypic and PCR tests for detecting virulence factors (VFs) was used to identify the isolates as K2 ST86 strains with common VFs, including Aerobactin and rmpA. Furthermore, the two K2 ST86 strains additionally harbored a distinct VF kfu (responsible for iron uptake system), which commonly existed in invasive K1 strains only. Thus, the unusual presence of both K1 and K2 VFs in the lethal ST86 strain might further enhance its hypervirulence and cause rapid onset of a life-threatening infection. Nevertheless, despite the administration of a combined antibiotic treatment, these three patients all died within 24 h of acute onset, thereby highlighting that the importance of early diagnosis to determine whether the ST86 strains harbor key K2 VF and unusual K1 kfu and whether patients should receive a timely and targeted antibiotic therapy to prevent ST86 induced fatal pneumonia. Finally, even though these patients are clinically improved, keeping on with oral antibiotic treatment for additional 2–3 weeks will be also vital for successfully preventing hvKP reinfection or relapse.

Comparative genomic and phenomic analysis of Clostridium difficile and Clostridium sordellii, two related pathogens with differing host tissue preference

Background

Clostridium difficile and C. sordellii are two anaerobic, spore forming, gram positive pathogens with a broad host range and the ability to cause lethal infections. Despite strong similarities between the two Clostridial strains, differences in their host tissue preference place C. difficile infections in the gastrointestinal tract and C. sordellii infections in soft tissues.

Results

In this study, to improve our understanding of C. sordellii and C. difficile virulence and pathogenesis, we have performed a comparative genomic and phenomic analysis of the two. The global phenomes of C. difficile and C. sordellii were compared using Biolog Phenotype microarrays. When compared to C. difficile, C. sordellii was found to better utilize more complex sources of carbon and nitrogen, including peptides. Phenotype microarray comparison also revealed that C. sordellii was better able to grow in acidic pH conditions. Using next generation sequencing technology, we determined the draft genome of C. sordellii strain 8483 and performed comparative genome analysis with C. difficile and other Clostridial genomes. Comparative genome analysis revealed the presence of several enzymes, including the urease gene cluster, specific to the C. sordellii genome that confer the ability of expanded peptide utilization and survival in acidic pH.

Conclusions

The identified phenotypes of C. sordellii might be important in causing wound and vaginal infections respectively. Proteins involved in the metabolic differences between C. sordellii and C. difficile should be targets for further studies aimed at understanding C. difficile and C. sordellii infection site specificity and pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1663-5) contains supplementary material, which is available to authorized users.

Characterization of Staphylococcus aureus Isolated from Non-Native Patients with Skin and Soft Tissue Infections in Shanghai

BACKGROUND

Staphylococcus aureus is one predominant cause of skin and soft-tissue infections (SSTIs), but little information exists regarding the characterization of S. aureus from non-native patients with SSTIs in China.

METHODS

In this study, we enrolled 52 non-native patients with S. aureus SSTIs, and 65 native control patients with S. aureus SSTIs in Shanghai. 52 and 65 S. aureus isolates were collected from both groups, respectively. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, spa type, agr group and SCCmec type.

RESULTS

Methicillin-resistant S. aureus (MRSA) was detected in 8 non-native patients and 14 native patients with SSTIs. Overall, antimicrobial susceptibilities of S. aureus isolated from non-native patients were found higher than those from native patients. CC59 (ST338 and ST59) was found in a total of 14 isolates (4 from non-native patients; 10 from native patients), 9 of which were carrying lukS/F-PV (3 from non-native patients; 6 from native patients). ST7 was found in 12 isolates and all 12 isolates were found in native patients. The livestock-associated clone ST398 was found in 11 isolates (6 from non-native patients; 5 from native patients), and 5 ST398 lukS/F-PV-positive methicillin-susceptible S. aureus (MSSA) were all discovered among non-native patients. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. lukS/F-PV was more frequent in isolates originating from non-native patients with SSTIs compared to native patients (31 vs. 7, P <0.0001).

CONCLUSIONS

CC59 was the most common clonal complex among patients with SSTIs in Shanghai. The other most common sequence types were ST7 and Livestock ST398. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. S. aureus isolated from non-native patients was more likely to carry lukS/F-PV.

Activation of the chromosomally encoded mazEF(Bif) locus of Bifidobacterium longum under acid stress

Toxin-antitoxin (TA) systems are distributed within the genomes of almost all free-living bacteria. Although the roles of chromosomally encoded TA systems are still under debate, they are suspected to be involved in various stress responses. Here, we provide the first report of a type II TA system in the probiotic bacterium Bifidobacterium longum. Bioinformatic analysis of the B. longum JDM301 genome identified a pair of linked genes encoding a MazEF-like TA system at the locus BLJ_811-BLJ_812. Our results showed that B. longum mazEF(Bif) genes form a bicistronic operon. The over-expression of MazF(Bif) was toxic to Escherichia coli and could be neutralized by the co-expression of its cognate antitoxin MazE(Bif). We demonstrated that MazEF(Bif) was activated during acid stress, which would most likely be encountered in the gastrointestinal tract. In addition, we found that the protease ClpPX(Bif), in addition to MazEF(Bif), was induced under acid stress. Furthermore, we examined antitoxin levels over time for MazEF(Bif) and observed that the antitoxin MazE(Bif) was degraded by ClpPX(Bif), which suggested that MazEF(Bif) was activated through the hydrolysis of MazE(Bif) by ClpP1X(Bif) and ClpP2X(Bif) under acid stress. Our results suggest that the MazEF(Bif) TA module may play an important role in cell physiology and may represent a cell growth modulator that helps bacteria to cope with acid stress in the gastrointestinal tract and environment.

Drug susceptibility and molecular epidemiology of Escherichia coli in bloodstream infections in Shanghai, China, 2011-2013

BACKGROUND

Prevention and management of Escherichia coli bloodstream infections (EC-BSIs) have become increasingly complicated by antimicrobial resistance and rapid dissemination. We investigated the antimicrobial epidemiology and phylogenetic background of clinical E. coli isolates from patients with bloodstream infections in Shanghai from 2011 to 2013.

METHODS

Escherichia coli isolates causing bloodstream infections were consecutively collected between June 2011 and June 2013. Antimicrobial susceptibility testing was performed by disk diffusion. Drug resistance genes coding for extended-spectrum β-lactamases (ESBLs) and carbapenemases, and phylogenetic groups were detected by polymerase chain reaction. eBURST was used for multilocus sequence typing.

RESULTS

Of the strains 128 collected, 80 produced ESBLs. No carbapenem-resistant isolates were found. The resistance rates to penicillins, fluoroquinolone, folate pathway inhibitors, tetracyclines and second generation cephalosporins were high. Molecular analysis showed that CTX-M-14 (40/80) was the most common β-lactamase, followed by CTX-M-55 (17/80) and CTX-M-15 (14/80). Phylogenetic group B2 predominated (37.5%), but phylogenetic group D exhibited the highest rates of ESBL production. ST131 (17/128) was the most common sequence type, followed by ST69 (12/128) and ST648 (10/128).

CONCLUSIONS

The antimicrobial resistance rate was high among EC-BSI isolates, but amikacin, piperacillin-tazobactam and carbapenem could be options for empiric therapy. Genetic diversity showed no correlation with the nosocomial origin of the isolates.

Isolation and characterization of two novel plasmids from pathogenic Leptospira interrogans serogroup Canicola Serovar Canicola strain Gui44

Background

Previous genomic analysis of pathogenic Leptospira has identified two circular chromosomes but no plasmid. This study aims to investigate potential extrachromosomal elements of L.interrogans serovar Canicola strain Gui44.

Methodology

Two novel plasmids, pGui1 and pGui2, were isolated from the pathogenic strain Gui44, using a modified alkaline lysis method. Southern blotting was performed to determine the presence and size of them. Then, 454 and Hiseq sequencing were applied to obtain and analyze the complete sequences of the two plasmids. Furthermore, real-time quantitative PCR and next-generation sequencing were used to compare relative copy numbers of the two plasmids with that of the chromosomes. Finally, after serial passages in vitro for more than 2 years, the strain Gui44 was subsequently re-sequenced to estimate stability of the two plasmids.

Principal Findings

The larger plasmid, pGui1, 74,981 base pairs (bp) in length with GC content of 34.63%, possesses 62 open reading frames (ORFs). The smaller plasmid, pGui2, is 66,851 bp in length with GC content of 33.33%, and contains 63 ORFs. The replication initiation proteins encoded by pGui1 and pGui2 demonstrate significant sequence similarity with LA1839 (86% and 88%), a well-known replication protein in another pathogenic L.interrogans serovar Lai strain Lai, suggesting the ability for autonomous plasmid replication. Quantitative PCR and next-generation sequencing confirms a single copy of both plasmids and their stable presence in the strain Gui44 with in vitro serial passages after more than 2 years. Interestingly, the two plasmids both contain a significant number of novel genes (35 in pGui1 and 52 in pGui2).

Conclusions

This report confirms the presence of two separate circular plasmids in serovar Canicola strain Gui44 and provides a new understanding of genomic organization, adaptation, evolution and pathogenesis of Leptospira, which will aid in the development of in vivo genetic manipulation systems in pathogenic Leptospira species.

Leptospira species are the causative agent of leptospirosis, one of the most common animal to human transmitted diseases. Previous genomic analysis of L.interrogans serovar Lai and Copenhageni has identified the presence of large (4.33 mega base) and small (350 kilo base) circular chromosomes without evidence of any plasmids. Detailed understanding of Leptospira and its pathogenicity was delayed by the lack of available genetic tools. In this study we confirm the existence of two novel plasmids in L.interrogans serovar Canicola strain Gui44, an epidemic strain in China. Some novel genes identified in the two plasmids may play important roles in the characterization of the strain. The two plasmids will provide useful information in understanding the diversity of Leptospira genome and markedly improve our understanding of the evolution and pathogenesis of L.interrogans. In particular, it will contribute to the development of genetic manipulation systems in pathogenic Leptospira species.

Mycobacterial 3-hydroxyacyl-l-thioester dehydratase Y derived from Mycobacterium tuberculosis induces COX-2 expression in mouse macrophages through MAPK-NF-κB pathway

Tuberculosis (TB) is a leading cause of global mortality due to infectious diseases. Expression of cyclooxygenase-2 (COX-2) acts as an important influencing factor favoring bacillary survival during TB infection. In this study, we investigated the Mycobacterium tuberculosis proteins recognized by sera from TB patient collected before and after anti-TB therapy by dynamic immunoproteomics and identified a novel immune-regulating protein 3-hydroxyacyl-l-thioester dehydratase Y (HtdY), which could induce COX-2 expression in mouse macrophages. Signaling perturbation data showed that the activation of p38, ERK 1/2 and JNK 1/2 MAPK as well as NF-κB played critical role in this immune response. Taken together, our findings indicated that mycobacterial HtdY might contribute to the persistence of the TB infection by inducing COX-2 expression through MAPK-NF-κB signaling pathway.

Characterization of a bifunctional enzyme with (p)ppGpp-hydrolase/synthase activity in Leptospira interrogans

Alarmone Guanosine 5'-diphosphate (or 5'-triphosphate) 3'-diphosphate [(p)ppGpp] is the key component that globally regulates stringent control in bacteria. There are two homologous enzymes, RelA and SpoT in Escherichia coli, which are responsible for fluctuations in (p)ppGpp concentration inside the cell, whereas there exists only a single RelA/SpoT enzyme in Gram-positive bacteria. We have identified a bifunctional enzyme with (p)ppGpp-hydrolase/synthase activity in Leptospira interrogans. We show that the relLin gene (LA_3085) encodes a protein that fully complements the relA/spoT double mutants in E. coli. The protein functions as a (p)ppGpp degradase as well as a (p)ppGpp synthase when the cells encounter amino acid stress and deprivation of carbon sources. N-terminus HD and RSD domains of relLin (relLinN ) were observed to restore growth of double mutants of E. coli. Finally, We demonstrate that purified RelLin and RelLinN show high (p)ppGpp synthesis activity in vitro. Taken together, our results suggest that L. interrogans contain a single Rel-like bifunctional protein, RelLin , which plays an important role in maintaining the basal level of (p)ppGpp in the cell potentially contributing to the regulation of bacterial stress response.

Corrosion behavior of pure titanium in the presence of Actinomyces naeslundii

It is well known that some microorganisms affect the corrosion of dental metal. Oral bacteria such as Actinomyces naeslundii may alter the corrosion behavior and stability of titanium. In this study, the corrosion behavior of titanium was studied in a nutrient-rich medium both in the presence and the absence of A. naeslundii using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). A. naeslundii was able to colonize the surface of titanium and then form a dense biofilm. The SEM images revealed the occurrence of micropitting corrosion on the metal surface after removal of the biofilm. The electrochemical corrosion results from EIS showed a significant decrease in the corrosion resistant (R(p)) value after immersing the metal in A. naeslundii culture for 3 days. Correspondingly, XPS revealed a reduction in the relative levels of titanium and oxygen and an obvious reduction of dominant titanium dioxide (TiO₂) in the surface oxides after immersion of the metal in A. naeslundii culture. These results suggest that the metabolites produced by A. naeslundii can weaken the integrity and stability of the protective TiO₂ in the surface oxides, which in turn decreases the corrosion resistance of titanium, resulting in increased corrosion of titanium immersed in A. naeslundii solution as a function of time.

Biocompatibility of chitosan-coated iron oxide nanoparticles with osteoblast cells

Background:

Bone disorders (including osteoporosis, loosening of a prosthesis, and bone infections) are of great concern to the medical community and are difficult to cure. Therapies are available to treat such diseases, but all have drawbacks and are not specifically targeted to the site of disease. Chitosan is widely used in the biomedical community, including for orthopedic applications. The aim of the present study was to coat chitosan onto iron oxide nanoparticles and to determine its effect on the proliferation and differentiation of osteoblasts.

Methods:

Nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, x-ray diffraction, zeta potential, and vibrating sample magnetometry. Uptake of nanoparticles by osteoblasts was studied by transmission electron microscopy and Prussian blue staining. Viability and proliferation of osteoblasts were measured in the presence of uncoated iron oxide magnetic nanoparticles or those coated with chitosan. Lactate dehydrogenase, alkaline phosphatase, total protein synthesis, and extracellular calcium deposition was studied in the presence of the nanoparticles.

Results:

Chitosan-coated iron oxide nanoparticles enhanced osteoblast proliferation, decreased cell membrane damage, and promoted cell differentiation, as indicated by an increase in alkaline phosphatase and extracellular calcium deposition. Chitosan-coated iron oxide nanoparticles showed good compatibility with osteoblasts.

Conclusion:

Further research is necessary to optimize magnetic nanoparticles for the treatment of bone disease.

Safety assessment of Bifidobacterium longum JDM301 based on complete genome sequences

AIM

To assess the safety of Bifidobacterium longum (B. longum) JDM301 based on complete genome sequences.

METHODS

The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resistance genes and genes encoding enzymes responsible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test.

RESULTS

JDM301 was shown to contain 36 genes associated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence factors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, amikacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imipenem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated.

CONCLUSION

The safety assessment of JDM301 using information derived from complete bacterial genome will contribute to a wider and deeper insight into the safety of probiotic bacteria.

Evaluation of a novel fusion protein antigen for rapid serodiagnosis of tuberculosis

The detection of Mycobacterium tuberculosis-specific antibodies in human sera has been a rapid and important diagnostic aid for tuberculosis (TB) control and prevention. However, any single antigen is not enough to be used to cover the antibody profiles of all TB patients. In this study, a novel fusion protein was constructed using gene splicing by overlap extension (SOEing), and then the antibody level against it in 171 TB patients and 86 controls was evaluated by enzyme-linked immunosorbent assay. Compared with the three individual antigen (16 kDa: sensitivity 19.9%, specificity 96.5%; MPT64: sensitivity 75.4%, specificity 34.9%; 38 kDa: sensitivity 33.3%, specificity 83.7%), the fusion protein antigen (sensitivity 42.1%, specificity 89.5%) gave the best diagnostic performance with the largest receiver operating characteristic curve area 0.656 (95% confidence interval [CI], 0.590-0.721; P<0.01). These results suggested that the novel fusion protein antigen successfully constructed by gene SOEing provided the improved diagnostic performance for TB, and other mycobacterial multiepitope fusion proteins may also be worthy of investigation for further enhancing the detection sensitivity.

Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route

Background

Leptospires are presumed to enter their host via small abrasions or breaches of the skin. The intraperitoneal route, although commonly used in guinea pig and hamster models of leptospirosis, does not reflect conditions encountered during natural infection. The aim of this study is to develop a novel leptospirosis guinea pig model through epicutaneous route and to elucidate the pathogenesis of leptospirosis in experimental guinea pigs by comparing the data from other studies using different infection routes.

Methods

The guinea pigs were inoculated with 5 × 10⁸ Leptospira interrogans strain Lai onto either shaved-only or abraded skin. The guinea pigs were sacrificed at 2, 8, 24, 48, 72, 96 and 144 h post-infection (p.i.) followed by harvest of the lungs, liver, kidneys, spleen, and the skin around the inoculated sites for further examinations. Hematoxylin and eosin (HE) staining and electron microscopy were used to detect the pathologic changes. Real time PCR and immunohistochemistry staining were performed to detect dynamic distribution of leptospires in blood and tissues, respectively.

Results

In the guinea pigs with abraded skin inoculations, leptospires were detected in blood as early as 2 h post infection (p.i.) and then disseminated to the liver, lungs and kidneys of almost all animals within 96 h p.i.. Leptospires were also detected engulfed in the swelling vascular endothelial cells and were frequently aggregated around the capillaries in the dermis and subcutaneous tissue under the inoculated site. For the guinea pigs with abraded skin inoculations, hemorrhage at the dermis around the inoculated site was found before the appearance of internal organs hemorrhage, severe lesions such as hemorrhages in the lungs, nephritis, jaundice, haematuria were also observed, and two of seven guinea pigs died at 144 h p.i. while no lesions and leptospires were detected in the shaved-only guinea pigs using the same dose of strain Lai.

Conclusion

Intact keratinocyte layer is a very efficient barrier against leptospires, and intact skin can prevent the infiltration of leptosipres to the host. Leptospires can penetrate abraded skin and quickly establish a systemic infection by crossing tissue barriers. We have successfully established a novel leptospirosis guinea pig model through epicutaneous inoculations route, which replicates a natural course of infection and appears to be an alternative way to investigate the pathogenesis of leptospirosis, especially in terms of early stage of host-pathogen interactions. This novel model may also be advantageous for studies of the mechanisms involved in cutaneous barriers and epidermal interactions with this organism.

Bacterial diversity of subgingival plaque in 6 healthy Chinese individuals

The subgingival microbial ecology is complex, and little is known regarding its bacteria species composition in healthy Chinese individuals. This study aimed to identify the subgingival microbiota from 6 healthy Chinese subjects. Subgingival samples from 6 volunteers were collected, the 16S rRNA gene was amplified using broad-range bacterial primers, and clone libraries were constructed. For the initial 2,439 sequences analyzed, 383 species-level operational taxonomic units (SLOTUs) belonging to seven phyla were identified, estimated as 51% [95% confidence interval (CI) 44-55] of the SLOTUs in this ecosystem. Most (85%) of the bacterial sequences, falling into 228 types of species, corresponded to known and cultivated species. However, 146 (6%) sequences, comprising 104 phylotypes, had <97% similarity to prior database sequences. Ten bacterial genera were conserved among all 6 individuals, comprising 2,000 (82%) of the 2,439 clones analyzed. Ten species were noted in all of the 6 subjects, comprising 1,435 (58.8%) of the 2,439 clones. Streptococcus infantis was the species most frequently cloned. Furthermore, certain species which may participate in the pathogenesis of periodontal disease were present in the 6 subjects. Although the initial subgingival plaque community of each subject was unique in terms of diversity and composition, 10 common key species were found in the 6 Chinese individuals. These ten species of bacteria in the human subgingival plaque in the 6 healthy individuals may be key species which, to some extent, affect periodontal health. Destruction of these key species in subgingival bacteria may break the microbiota balance and may easily lead to over-breeding conditions resulting in pathogenic oral disease.

α-Galactosylceramide protects mice from lethal Coxsackievirus B3 infection and subsequent myocarditis

Myocarditis is an inflammation of the myocardium which often follows virus infections. Coxsackievirus B3 (CVB3), as a marker of the enterovirus group, is one of the most important infectious agents of virus-induced myocarditis. Using a CVB3-induced myocarditis model, we show that injection α-galactosylceramide (α-GalCer), a ligand for invariant natural killer (NK) T (iNK T) cells, can protect the mice from viral myocarditis. After the systemic administration of α-GalCer in CVB3 infected mice, viral transcription and titres in mouse heart, sera and spleen were reduced, and the damage to the heart was ameliorated. This is accompanied by a better disease course with an improved weight loss profile. Compared with untreated mice, α-GalCer-treated mice showed high levels of interferon (IFN)-γ and interleukin (IL)-4, and reduced proinflammatory cytokines and chemokines in their cardiac tissue. Anti-viral immune response was up-regulated by α-GalCer. Three days after CVB3 infection, α-GalCer-administered mice had larger spleens. Besides NK T cells, more macrophages and CD8(+) T cells were found in these spleens. Upon stimulation with phorbol myristate acetate plus ionomycin, splenocytes from α-GalCer-treated mice produced significantly more cytokines [including IFN-γ, tumour necrosis factor-α, IL-4 and IL-10] than those from untreated mice. These data suggest that administration of α-GalCer during acute CVB3 infection is able to protect the mice from lethal myocarditis by local changes in inflammatory cytokine patterns and enhancement of anti-viral immune response at the early stage. α-GalCer is a potential candidate for viral myocarditis treatment. Our work supports the use of anti-viral treatment early to reduce the incidence of virus-mediated heart damage.

Adhesion and immunomodulatory effects of Bifidobacterium lactis HN019 on intestinal epithelial cells INT-407

AIM: To elucidate the adherence and immunomodulatory properties of a probiotic strain Bifidobacterium lactis (B. lactis) HN019.

METHODS: Adhesion assays of B. lactis HN019 and Salmonella typhimurium (S. typhimurium) ATCC 14028 to INT-407 cells were carried out by detecting copies of species-specific genes with real-time polymerase chain reaction. Morphological study was further conducted by transmission electron microscopy. Interleukin-1β (IL-1β), interleukin-8, and tumor necrosis factor-α (TNF-α) gene expression were assessed while enzyme linked immunosorbent assay was used to detect IL-8 protein secretion.

RESULTS: The attachment of S. typhimurium ATCC 14028 to INT407 intestinal epithelial cells was inhibited significantly by B. lactis HN019. B. lactis HN019 could be internalized into the INT-407 cells and attenuated IL-8 mRNA level at both baseline and S. typhimurium-induced pro-inflammatory responses. IL-8 secretion was reduced while IL-1β and TNF-α mRNA expression level remained unchanged at baseline after treated with B. lactis HN019.

CONCLUSION: B. lactis HN019 does not up-regulate the intestinal epithelium expressed pro-inflammatory cytokine, it showed the potential to protect enterocytes from an acute inflammatory response induced by enteropathogen.

Development of O-antigen gene cluster-specific PCRs for rapid typing six epidemic serogroups of Leptospira in China

Background

Leptospira is the causative agent of leptospirosis. The O-antigen is the distal part of the lipopolysaccharide, which is a key component of outer membrane of Gram-negative bacteria and confers serological specificity. The epidemiology and clinical characteristics of leptospirosis are relative to the serology based taxonomic unit. Identification of Leptospira strains by serotyping is laborious and has several drawbacks.

Results

In this study, the O-antigen gene clusters of four epidemic Leptospira serogroups (serogroup Canicola, Autumnalis, Grippotyphosa and Hebdomadis) in China were sequenced and all genes were predicted in silico. Adding published sequences of two serogroups, Icterohaemorrhagiae (strain Lai and Fiocruz L1-130) and Sejroe (strain JB197 and L550), we identified six O-antigen-specific genes for six epidemic serogroups in China. PCR assays using these genes were developed and tested on 75 reference strains and 40 clinical isolates.

Conclusion

The results show that the PCR-based assays can be reliable and alternative means for rapid typing of these six serogroups of Leptospira.

Evidence for calcifying nanoparticles in gingival crevicular fluid and dental calculus in periodontitis

BACKGROUND

Calcifying nanoparticles (CNPs), also known as nanobacteria, can produce carbonate apatite on their cell walls and initiate pathologic calcification. The objective of this study was to determine whether CNPs are present in the gingival crevicular fluid (GCF) from subjects with periodontal disease and whether they can induce the pathologic calcification of primary cultured human gingival epithelial cells.

METHODS

GCF and dental calculus samples were collected from 10 subjects with gingivitis and 10 subjects with chronic periodontitis. CNPs in GCF and calculus filtrates were detected with nanocapture enzyme-linked immunosorbent assay kits. The CNPs in cultures of dental calculus filtrates were also identified using immunofluorescence staining, transmission electron microscopy (TEM), and chemical analysis. Pathologic changes in the CNP-treated gingival epithelial cells were observed with TEM, alizarin red staining, and disk-scanning confocal microscopy.

RESULTS

CNPs were found in GCF samples from two subjects with chronic periodontitis. Based on chemical analysis, the surface-associated material from CNPs isolated and cultured from calculus has a composition similar to dental calculus. The pathologic calcification of CNP-treated gingival epithelial cells was also observed.

CONCLUSIONS

Self-replicating calcifying nanoparticles can be cultured and identified from dental calculus. This raises the issue of whether CNPs contribute to the pathogenesis of periodontitis.

High-coverage proteome analysis reveals the first insight of protein modification systems in the pathogenic spirochete Leptospira interrogans

Leptospirosis is a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira that infects humans and a wide range of animals. By combining computational prediction and high-accuracy tandem mass spectra, we revised the genome annotation of Leptospira interrogans serovar Lai, a free-living pathogenic spirochete responsible for leptospirosis, providing substantial peptide evidence for novel genes and new gene boundaries. Subsequently, we presented a high-coverage proteome analysis of protein expression and multiple posttranslational modifications (PTMs). Approximately 64.3% of the predicted L. interrogans proteins were cataloged by detecting 2 540 proteins. Meanwhile, a profile of multiple PTMs was concurrently established, containing in total 32 phosphorylated, 46 acetylated and 155 methylated proteins. The PTM systems in the serovar Lai show unique features. Unique eukaryotic-like features of L. interrogans protein modifications were demonstrated in both phosphorylation and arginine methylation. This systematic analysis provides not only comprehensive information of high-coverage protein expression and multiple modifications in prokaryotes but also a view suggesting that the evolutionarily primitive L. interrogans shares significant similarities in protein modification systems with eukaryotes.

Antibiotic resistance of probiotic strains of lactic acid bacteria isolated from marketed foods and drugs

OBJECTIVE

To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probiotics.

METHODS

Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR.

RESULTS

Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis.

CONCLUSION

Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.

Influence of E3 region on conditionally replicative adenovirus mediated cytotoxicity in hepatocellular carcinoma cells

Virotherapy employing conditionally replicative adenovirus (CRAd) represents a novel targeted strategy for the hepatocellular carcinoma (HCC) treatment. In this study, we explored the potential influence of E3 region, which encodes several TRAIL-inhibiting proteins (E3-6.7K, E3-10.4K/14.5K and E3-14.7K), on CRAd mediated cytotoxicity to HCC cells. Two E1B-55 kDa-deleted CRAds containing E3 region (Ad.DeltaE1B) or no E3 region (Ad.DeltaE1B.DeltaE3) were fabricated. Ad.DeltaE1B.DeltaE3 exhibited higher cytocidal potency than Ad.DeltaE1B in all tested HCC cells (Hep3B, BEL-7404, BEL-7402, HuH7, PLC/PRF/5 and HepG2), suggesting that Ad.DeltaE1B.DeltaE3 mediated cytotoxicity was partly attributed to the absence of E3 region encoding TRAIL-inhibiting proteins. In representative Hep3B cells, Ad.DeltaE1B.DeltaE3 led to more drop of mitochondrial membrane potential (MMP) and much lower ATP level than Ad.DeltaE1B. Moreover, Ad.DeltaE1B.DeltaE3 induced early apoptotic cells and the late apoptotic/necrotic cells for three and four times more than those infected by Ad.DeltaE1B. The cytotoxicity to all TRAIL endogenously expressing HCC cells and MMP drop of Hep3B cells induced by Ad.DeltaE1B.DeltaE3 but not Ad.DeltaE1B could be significantly inhibited by z-vad-fmk, a pan caspase inhibitor, suggesting that the endogenous TRAIL-mediated apoptotic pathway may be implicated in the cytocidal potency of Ad.DeltaE1B.DeltaE3 on HCC cells although other unknown mechanisms may be also involved. Our findings provided the first evidence that CRAd without E3 region might be a smart choice for the virotherapy of HCC.