Chinese Center for Disease Control and Prevention

About: Chinese Center for Disease Control and Prevention is a government organization based out in Beijing, China. It is known for research contribution in the topics: Population & Acquired immunodeficiency syndrome (AIDS). The organization has 16037 authors who have published 15098 publications receiving 423452 citations. The organization is also known as: China CDC & CCDC.

Balancing mcr-1 expression and bacterial survival is a delicate equilibrium between essential cellular defence mechanisms.

Abstract: MCR-1 is a lipid A modifying enzyme that confers resistance to the antibiotic colistin. Here, we analyse the impact of MCR-1 expression on E. coli morphology, fitness, competitiveness, immune stimulation and virulence. Increased expression of mcr-1 results in decreased growth rate, cell viability, competitive ability and significant degradation in cell membrane and cytoplasmic structures, compared to expression of catalytically inactive MCR-1 (E246A) or MCR-1 soluble component. Lipopolysaccharide (LPS) extracted from mcr-1 strains induces lower production of IL-6 and TNF, when compared to control LPS. Compared to their parent strains, high-level colistin resistance mutants (HLCRMs) show reduced fitness (relative fitness is 0.41–0.78) and highly attenuated virulence in a Galleria mellonella infection model. Furthermore, HLCRMs are more susceptible to most antibiotics than their respective parent strains. Our results show that the bacterium is challenged to find a delicate equilibrium between expression of MCR-1-mediated colistin resistance and minimalizing toxicity and thus ensuring cell survival.

Safety and immunogenicity from a phase I trial of inactivated severe acute respiratory syndrome coronavirus vaccine.

Abstract: Background Emergence of severe acute respiratory syndrome (SARS) from the winter of 2002 to the spring of 2003 has caused a serious threat to public health. Methods To evaluate the safety and immunogenicity of the inactivated SARS coronavirus (SARS-CoV) vaccine, 36 subjects received two doses of 16 SARS-CoV units (SU) or 32 SU inactivated SARS-CoV vaccine, or placebo control. Results On day 42, the seroconversion reached 100% for both vaccine groups. On day 56, 100% of participants in the group receiving 16 SU and 91.1% in the group receiving 32 SU had seroconverted. The geometric mean titre of neutralizing antibody peaked 2 weeks after the second vaccination, but decreased 4 weeks later. Conclusion The inactivated vaccine was safe and well tolerated and can elicit SARS-CoV-specific neutralizing antibodies.

Dynamic reassortments and genetic heterogeneity of the human-infecting influenza A (H7N9) virus.

Abstract: Influenza A (H7N9) virus has been causing human infections in China since February 2013, raising serious concerns of potential pandemics. Previous studies demonstrate that human infection is directly linked to live animal markets, and that the internal genes of the virus are derived from H9N2 viruses circulating in the Yangtze River Delta area in Eastern China. Here following analysis of 109 viruses, we show a much higher genetic heterogeneity of the H7N9 viruses than previously reported, with a total of 27 newly designated genotypes. Phylogenetic and genealogical inferences reveal that genotypes G0 and G2.6 dominantly co-circulate within poultry, with most human isolates belonging to the genotype G0. G0 viruses are also responsible for the inter- and intra-province transmissions, leading to the genesis of novel genotypes. These observations suggest the province-specific H9N2 virus gene pools increase the genetic diversity of H7N9 via dynamic reassortments and also imply that G0 has not gained overwhelming fitness and the virus continues to undergo reassortment.

Effect of meteorological variables on the incidence of hand, foot, and mouth disease in children: a time-series analysis in Guangzhou, China

Abstract: Over the last decade, major outbreaks of hand, foot, and mouth disease (HFMD) have been reported in Asian countries, resulting in thousands of deaths among children. However, less is known regarding the effect of meteorological variables on the incidence of HFMD in children. This study aims at quantifying the relationship between meteorological variables and the incidence of HFMD among children in Guangzhou, China. The association between weekly HFMD cases in children aged <15 years and meteorological variables in Guangzhou from 2008 to 2011 were analyzed using the generalized additive model (GAM) and time-series method, after controlling for long-term trend and seasonality, holiday effects, influenza period and delayed effects. Temperature and relative humidity with one week lag were significantly associated with HFMD infection among children. We found that a 1°C increase in temperature led to an increase of 1.86% (95% CI: 0.92, 2.81%) in the weekly number of cases in the 0–14 years age group. A one percent increase in relative humidity may lead to an increase of 1.42% (95% CI: 0.97, 1.87%) in the weekly number of cases in the 0–14 years age group. This study provides quantitative evidence that the incidence of HFMD in children was associated with high average temperature and high relative humidity. The one-week delay in the effects of temperature and relative humidity on HFMD is consistent with the enterovirus incubation period and the potential time lag between onset of children’s sickness and parental awareness and response.