ISSN 1673-6184 CN 31-1966/R
The purpose of the present study is to monitor the etiological and epidemiological characteristics of hospitalized children with hand, foot and mouth disease (HFMD) in Shanghai, 2014. The stool samples, epidemiological and clinical data of hospitalized children with HFMD in Children’s Hospital of Fudan University were collected in 2014. One-step real-time fluorescence quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR were performed for enterovirus detection and typing. Among 19 622 children with HFMD, 1 059 (5.4%) were hospitalized and 547 inpatients were included into this study. Enterviruses were confirmed virologically in 448 (81.9%) children and nine types of enteroviruses were identified. EV71 was more prevalent during February and July; CA16 was relatively prevalent during June and September; CA6 was sporadic from January to July, but prevalent during August and December. One hundred and sixty-two (29.6%) cases had close contact with children suffering from HFMD or herpangina. Two hundred and ten (19.8%) cases were confirmed as severe cases with meningitis or encephalitis. The detection rates of EV71, CA16 and CA6 were 30.3% (70/231), 1.2% (1/83) and 0.9% (1/115)in severe cases, respectively. The results showed that HFMD was prevalent in Shanghai, 2014, and peaked in summer and autumn. Multiple enteroviruses co-circulated in HFMD children. Most cases had no definite exposure history. EV71, CA6 and CA16 were the predominant viruses causing the epidemics of HFMD in Shanghai, 2014, and EV71 remained the major cause for severe diseases.
In order to investigate the epidemic of hepatitis E virus (HEV) in human immunodeficiency virus (HIV)-infected patients，235 serum samples collected from HIV-infected patients were subjected to molecular detections for HEV infection, these including enzyme-linked immunosorbent assay (ELISA) for HEV IgG and IgM and antigen, and polymerase chain reaction (PCR) method for HEV RNA. Roche COBAS®AmpliPrep/COBAS®TaqMan HIV-1 Test was applied for HIV levels. No HEV RNA-positive results were found in this study. The positive rate of HEV IgG antibody in intravenous drug users, blood component donors and unexplained HIV infection population were 49.3%, 39.5% and 30.4%, respectively, and the collective positive rate in HIV-infected patients was 37.4%. There was no statistically significant difference (χ2＝2.978, P>0.05) in HIV viral load among three HIV-infected groups, and between HEV IgG-positive and -negative populations (P>0.05). The results suggest that more studies are required to elucidate the role of HEV infection in HIV patients, and to establish effective preventive measures, including vaccine inoculation for HIV-infected patients.
The interaction between pathogenic microbes and host cells is crucial for studies on infections and tumor cell biology. The kinetic studies of cell cycle are of significance for understanding the mechanisms mediated by microbes versus host cells. In this paper, a novel method for cell cycle analysis in mouse splenic cells by Ki67 and 4′，6-diamidino-2-phenylindole (DAPI) or propidium iodide (PI) co-staining is introduced.
The aim of this study is to investigate the immune regulation function of scavenger receptor class A type I (SR-AI) on macrophages for the treatment of two common pathogens of respiratory tract: Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa). The clinical isolates of K. pneumoniae and P. aeruginosa were collected. They were stained by fluorescent dyes and subjected to the peritoneal macrophages prepared from wide-type (WT) and SR-AI－/－ mice respectively. The results showed that SR-AI－/－ macrophages had lower phagocytic ability to K. pneumoniae, but higher phagocytic ability to P. aeruginosa than WT macrophages. Quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect mRNA expressions of inflammatory cytokines. The results showed that the inflammatory reactions of SR-AI－/－ macrophages were significantly improved than WT macrophages after infection of K. pneumoniae and P. aeruginosa. The data suggest that SR-AI could participate in the phagocytosis of K. pneumoniae by macrophages, but not in the phagocytosis of P. aeruginosa. Besides, SR-AI plays a role in downregulation of inflammatory reactions induced by infection of K. pneumoniae and P. aeruginosa.
In photodynamic therapy (PDT), the reactive oxygen species generated by the activation of photosensitizers by light of an appropriate wavelength, are able to inactivate microbes by damaging various microbial components. Due to its multi-targeting antimicrobial capability, PDT has shown a potential as an effective alternative therapeutic option against methicillin-resistant Staphylococcus aureus (MRSA). In this study, MRSA strains isolated from burn, acute pharyngitis, nasosinusitis and pneumonia patients were subjected to a 5-aminolevulinic acid (ALA) mediated light emitting diode (LED) array in vitro. The results showed that a significant reduction (1.8 log10 cfu) was achieved with an ALA treatment (1 h, 5 mmol/L) followed by 1 h of illumination [(633±10) nm wavelength light source, and a 360 J/cm2 light dose]. MRSA strains collected from different tissues showed a similar sensitivity to the treatment.
Ribosomes of pathogenic bacteria are major targets for antibiotics, and how to prepare ribosome samples with quality and quantity is a key step for structure and antibiotic studies. In particular, it is a challenge to purify enough ribosome from slow-growing Mycobacterium such as Mycobacterium tuberculosis due to slow growth rate and thick cell wall. With the optimized steps, including growing and processing bulk culture with biosafety measures, breaking the thick cell wall of Gram-positive bacteria with effective techniques, and purification methods to combine the fast protein liquid chromatography (FPLC) and sucrose gradient separation, enough ribosome samples with high purity were obtained from Mycobacterium. The prepared samples could be subjected to complex specificity studies, such as high-resolution structure studies with X-ray crystallography and cryo-electron microscopy (cryo-EM), and shed light on the mechanism of antibiotics. This improved method is applicable in other Gram-positive bacteria.
Aspergillus fumigatus (A. fumigatus) is a widespread opportunistic pathogen. The conidia produced by A. fumigatus are colonized in lungs after inhalation, leading to aspergilloma, allergic bronchopulmonary aspergillosis (ABPA) and invasive aspergillosis (IA). Currently, 1，3-β-D-glucan and galactomannan are used as serum immunological indexes for clinical diagnosis of A. fumigatus infection. Asp f3 and Asp f4 are two of the major antigens of A. fumigatus, and the corresponding circulating antibodies are present in the sera of infected persons. In this study, anti-Asp f3 and anti-Asp f4 rabbit sera were used to carry out antigen epitope scanning. Eight Asp f3 and six Asp f4 minimal motifs were identified. These identified minimal motifs can be used for constructing chimera antigens to improve the specificity and sensitivity of the diagnosis for A. fumigatus infection.
To improve the understanding of the clinical manifestations and dangers of liver abscess invasive syndrome caused by Klebsiella pneumoniae (K. pneumoniae) infection, the clinical courses, including treatment and outcomes of three cases were retrospectively analyzed. All infections were community-acquired. Their clinical manifestations and blood culture test results were in line with the clinical features of liver abscess invasive syndrome caused by K. pneumoniae infection. All had liver abscesses; two cases had complications with endophthalmitis leading to blindness; one patient was complicated with lumbar and abdominal aortic infection and infectious endocarditis. Two patients had diabetes history, and one patient was normal immunocompetent. The liver abscess invasive syndrome caused by K. pneumoniae infection should get more clinical attentions because it is hard to treat and may cause serious clinical dangers, not only liver abscess but also extrahepatic disseminated lesions. It is detected not only in diabetic and immunodeficient populations but also in the normal immunocompetent population.
The intracellular DNA sensors in host cells recognize viral nucleic acid and activate the innate immunity, then resulting in antiviral effects. However, the viral pathogens have also evolved with appropriate strategies to evade or suppress the innate immune responses. In this review, the characteristics and molecular mechanisms of the immune effects of PYHIN family, one of the DNA sensors in host cells that could recognize viral DNA and activate innate immunity are discussed. The strategies of how viruses escape from the immune surveillance are also summarized.
