In order to explore the genetic variation and molecular characteristics of H9N2 subtype avian influenza viruses in Shanghai, fourteen H9N2 subtype avian influenza viruses were isolated from live poultry markets, poultry farms and pig slaughterhouses in 2002 and 2006－2014. These specimens included paired tracheal and cloacal swabs from chickens, ducks, pigeons and domestic wild chickens and lung samples from pigs. They were determined as H9 subtype by real－time reverse transcriptase－polymerase chain reaction (RT－PCR) and then isolated by using 10－day－old specific pathogen free chicken eggs, further identified as H9 subtype by hemagglutination inhibition (HI) test. The eight gene segments of the fourteen virus strains were amplified by RT－PCR and sequenced. Phylogenetic analysis revealed that the isolates were reassortants mainly of A/chicken/Shanghai/F/1998, A/duck/HongKong/Y280/1997, A/quail/ HongKong/G1/1997. Five virus strains isolated from 2002 and 2006－2008 represented four different genotypes. The other nine virus strains isolated in 2008－2014 was different from the above four genotypes. This may be related to the pressure of immune selection by vaccine.

To study the impact of T131N/M133T substitutions in hepatitis B virus surface antigen (HBsAg), the proteins expressed in Huh7 and HeLa cells were subjected to Western blotting, enzyme－linked immunosorbent assay (ELISA) and immunofluorescence (IF) staining. The results showed that T131N/M133T substitutions created a new site for N－glycosylation. The detected level of T131N/M133T was significantly low, indicating a potential negative impact on stability and antigenicity of HBsAg.

The present paper aims to explore the synergistic effect of maraviroc (MRV) [an inhibitor of human immunodeficiency virus type 1 (HIV－1) co－receptor chemokine (C－C motif) receptor 5 (CCR5)] and sifuvirtide (SFT) (HIV－1 entry inhibitor) on HIV infection. Three HIV－1 pseudovirus strains including SVPB16, SVPC12 and CRF01_AE subtypes were used to infect TZM－bl cells in vitro. The effects of MRV and SFT, alone or combined, on the HIV－1/TZM－bl infection system were investigated, and their 50% effective concentration (EC₅₀) values were calculated. The synergistic effect of SFT and MRV was predicted by CalcuSyn software according to the combined index (CI) values. The CI values indicated a synergistic effect when <1, an antagonistic effect when >1, and an additive effect when equal to 1. The cytotoxic effects of MRV and SFT, alone or combined, were also evaluated by methylthiazolyl tetrazolium (MTT) method. When used alone, the EC₅₀ values of SFT were 0.91, 0.17 and 0.71 nmol/L against SVPB16, SVPC12 and CRF01_AE pseudoviruses, respectively; and the EC₅₀ values of MRV were 4.84, 0.47 and 0.45 nmol/L, respectively. When SFT and MRV were used in combination, the EC₅₀ values of them were reduced by two to four times for SFT (0.45, 0.09 and 0.15 nmol/L), and two to three times for MRV (1.52, 0.12 and 0.11 nmol/L). The results calculated by isobologram software indicated that there was a good synergistic effect between SFT and MRV. It is suggested that combination of SFT and MRV has a good synergistic effect on HIV－1 infection in vitro with no significant cell toxicity.

Infections granuloma is a kind of chronic hyperplastic inflammation which is rarely caused by Actinomyces and Nocardia. As clinical symptoms and physical examination results of infectious granuloma caused by Actinomyces and Nocardia are similar, it is easily to lead to misdiagnosis or missed diagnosis. Here we presented a case of infectious granuloma caused by Actinomyces and a case of infectious granuloma caused by Nocardia. The final diagnosis was confirmed by pathological examination, bacterial culture and identification, and gene sequencing. We also summarized the etiology, epidemiology, clinical features, differential diagnosis, treatment and recent advances in these two infections, which could help to make the correct diagnosis without delay and choose the optimal treatment. There two infections have many similarities, and we need to distinguish them for proper therapy. The differential diagnosis with other granulomatous infections, such as tuberculosis, cutaneous sporotrichosis or chromoblastomycosis was also discussed.

The main purpose of the research is to evaluate the application feasibility of multiplex polymerase chain reaction (PCR) in serotyping of Streptococcus pneumoniae. A total of 568 strains were subjected to multiplex PCR and capsular swelling test respectively. The results demonstrated that 37.5% of the strains (213/568) could be successfully serotyped by capsular swelling test into 16 different serotypes, including serotypes 19 (23.1%, 131/568), 6 (5.3%, 30/568), 23 (1.6%, 9/568), 14 (1.4%, 8/568), 9 (1.1%, 6/568) and 15 (1.1%, 6/568); while 62.7% of the strains (356/568) could be successfully serotyped by multiplex PCR into 21 different serotypes, including serotypes 19 (27.8%, 158/568), 23 (8.5%, 48/568), 6 (7.4%, 42/568), 14 (4.4%, 25/568), 3 (4.2%, 24/568) and 15 (3.5%, 20/568). The multiplex PCR could not identify serotypes 4 and 18 which could be identified by capsular swelling test, while the capsular swelling test could not identify serotypes 5, 12, 35, 16, 17 and 22 which could be successfully identified by multiplex PCR. There was no significant difference between the two methods to identify serotypes 19F and 19A. The results suggest that there is significant difference between the two methods in serotyping of Streptococcus pneumoniae. Multiplex PCR is more effective than the conventional capsular swelling test, especially for those specimens collected from complicated sources. The combination of the two methods can improve the serotyping efficiency of Streptococcus pneumoniae.

This study aims to evaluate the efficacy of phage therapy against Serratia marcescens infections in mice and to provide the basis of phage therapy applied in bacterial infections. Double－agar overlay plaque method was employed to screen lytic phages from sewage, using Serratia marcescens isolates as hosts. Serratia marcescens strains at minimal lethal dose (MLD) were injected intraperitoneally (i.p.) into BALB/c mice and an i．p. of phage was followed. The survival rate of animals and protective dose of phage were examined at different time points (0, 20, 40, 60 and 180 min) after the bacterial challenge. Pharmacokinetics of phages injected alone or with bacteria was analyzed respectively. The results showed that a lytic phage, designated φSM9－3Y, was isolated and characterized from sewage. Electron microscope revealed that phage φSM9－3Y was in Siphoviridae family, Caudovirales order. After injection of Serratia marcescens isolates, immediate phage therapy at dose of 10⁸ PFU/ml reached a protection rate of 100%. The protection rate was around 60% with a phage therapy (10¹⁰ PFU/ml) delivered 60 min after the infection. Pharmacokinetics analysis showed that phage titer in blood was maintained at level of 10¹⁰ PFU/ml within 6 h when phages were injected i．p. together with bacteria. These data indicate that phages can save animals from pathogenic Serratia marcescens infection and suggest that phage therapy may be potentially used for the control of bacterial infections.

Norovirus is the pathogen causing recent outbreaks of acute viral gastroenteritis in Beijing, Shanghai, Zhejiang and Guangdong in China. This short review introduces the biological and epidemiological characteristics of Norovirus and the current development of vaccine against its infection.

Human cytomegalovirus (HCMV) is a widespread opportunistic pathogen, causing chronic and persistent infections by controlling body’s immune system. During the long evolution process of the virus and the host, the virus has developed mechanisms to evade the host immune system. The viral genome encodes a large number of products to control the central functions of both innate and adaptive immunity of the host by inhibiting the functions of natural killer (NK) cells and dendritic cells, down－regulating the expressions of major histocompatibility complex (MHC) class I and II in infected cells, impairing IgG－mediated humoral immunity as well as regulating the functions of chemokines and cytokines. This paper reviews the immune interfering mechanisms by HCMV, and probes into the occurrence, development and outcomes of the interaction between the virus and the host.

With the wide use of antifungals in the clinic, there have been increasing reports of resistant strains of Aspergillus spp. to antifungals. The resistance of Aspergillus spp. has important impact on the diagnosis and treatment of invasive aspergillosis. Currently, the determination of antifungal resistance of pathogenic Aspergillus spp. relies on antifungal susceptibility testing and molecular detection. Recently, the resistance of Aspergillus spp. to antifungals is mainly focused on azole antifungals. The research progress on antifungal resistance of pathogenic Aspergillus spp., including the diagnosis for resistance and the molecular mechanisms, such as over－expression of efflux pumps, mutations in the target enzyme (Cyp51), formation of biofilm and heat shock protein 90 (Hsp90)－mediated signaling pathways are reviewed.

Cryptococcus neoformans species complex is one of the most common fungal pathogens for solid organ transplantation, which invades the host mostly through respiratory tract and then disseminated to remote organs especially central nervous system. Without prompt treatment, cryptococcal infection has very high mortality and morbidity. The main risk factors include preoperative fever, postoperative application of antibiotics and immunosuppressors, postoperative bacterial and (or) viral infection, and the large dose use of glucocorticoid. Due to its lack of unique clinical features, it is difficult to make early diagnosis of cryptococcal infection. At present, amphotericin B, fluconazole and flucytosine are still the first－line drugs. The exact therapeutic regimen depends on the immune status and organ function of the host. This review mainly focuses on the progress in the diagnosis and treatment of cryptococcal infection after solid organ transplantation.

Bacterial secretion systems are responsible for the secretion of bacterial produced moleculars or DNA, and closely related to the growth and pathogenicity of bacteria. So far, seven types of secretion systems have been identified. TypesⅠ－Ⅵ exist in Gram－negatives and types Ⅳ and Ⅶ exist in Gram－positives. Type Ⅶ secretion system (T7SS) is identified recently. It is involved in the secretion of virulence－associated proteins, the interaction between pathogens and hosts, and the balance of zinc/iron ions, and is implicated in growth and pathogenesis of Gram－positive bacteria. The classification, regulation and biological functions of T7SS are reviewed in the present paper.