Streptococcus suis serotype 2 (SS2) is widely recognized in the veterinary world as the cause of rapidly progressive and fatal sepsis in infant pigs, manifested with meningitis, polyarthritis and pneumonia. It has evolved into a highly infectious strain, and caused two large-scale outbreaks of human epidemic in China, characterized bytypical toxic-shock syndrome and invasive infection. However, the molecular basis of virulence of this emerging zoonotic pathogen is still largely unknown. The present study shows that the sequence type (ST)7 epidemic strain S. suis 05ZYH33 causes higher mortality, higher necrosis of polymorphonuclear neutrophils and a significantly higher damage to human umbilical vein endothelial cells compared to the non-epidemic strain S. suis 1940. These differences appear to associate with the enhanced secretion of suilysin (sly) by S. suis 05ZYH33 compared to the non-epidemic strain 1940. Inclusion of additional strains confirmed that the epidemic ST7 strains produce more sly protein (mean, 1.49 g/ml; range, 0.76–1.91 g/ml) than non-epidemic strains (mean, 0.33 g/ml; range, 0.07–0.94 g/ml), and this difference is significant (P<0.001). The nonpolar mutant strain S. suis Δsly, constructed from the epidemic ST7 strain S. suis 05ZYH33 confirmed the role of sly on the enhanced virulence of S. suis ST7 strains. These findings suggest that increased sly production in S. suis 05ZYH33 facilitates penetration to the epithelium and its survival in the bloodstream, thereby contributing to the invasive infection.

Background: Polarized M2 macrophages are an important type of tumor-associated macrophage (TAM), with roles in the growth, invasion, and migration of cancer cells in the tumor microenvironment. Dihydroartemisinin (DHA), a traditional Chinese medicine extract, has been shown to inhibit the progression and metastasis of head and neck squamous cell carcinoma (HNSCC); however, the effect of DHA on cancer prevention, and the associated mechanism, has not been investigated in the tumor microenvironment. Materials and Methods: First, human Thp-1 monocytes were induced and differentiated into M2 macrophages using phorbol 12-myristate 13-acetate (PMA), interleukin-6 (IL-6), and interleukin-4 (IL-4). Induction success was confirmed by cell morphology evaluation, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR). Then, DHA was applied to interfere with M2 macrophage polarization, and conditioned medium (CM), including conditioned medium from M2 macrophages (M2-CM) and conditioned medium from M2 macrophages with DHA (M2-DHA-CM), was obtained. CM was applied to Fadu or Cal-27 cells, and its effects on cancer invasion, migration, and angiogenesis were evaluated using transwell, wound-healing, and tube formation assays, respectively. Finally, Western blotting was used to evaluate the relationship between signal transducer and activator of transcription 3 (STAT3) signaling pathway activation and M2 macrophage polarization. Results: Human Thp-1 monocytes were successfully polarized into M2-like TAMs using PMA, IL-6, and IL-4. We found that M2-like TAMs promoted the invasion, migration, and angiogenesis of HNSCC cells; however, DHA significantly inhibited IL-4/IL-6-induced M2 macrophage polarization. Additionally, as DHA induced a decrease in the number of M2-like TAMs, M2-DHA-CM inhibited the induction of invasion, migration, and angiogenesis of Fadu and Cal-27 cells. Finally, DHA inhibited M2 macrophage polarization by blocking STAT3 pathway activation in macrophages. Conclusion: DHA inhibits the invasion, migration, and angiogenesis of HNSCC by preventing M2 macrophage polarization via blocking STAT3 phosphorylation.

Early and accurate diagnosis of invasive candidiasis (IC) is very important. In this study, a lateral flow immunoassay (LFIA) was developed to detect antibody against Candida albicans enolase (Eno). Colloidal gold particle labeled mouse anti human IgG (1.0 mg/L) was used as the detector reagent. Recombinant enolase (rEno, 1.0 mg/L) and goat anti IgG (1.0 mg/L) were immobilized in test and control lines, respectively, of a nitrocellulose membrane, acting as the capture reagents. The LFIA was used to detect anti Eno in 38 sera from clinically proven IC patients, as well as in 50 healthy control subjects. Compared with an indirect ELISA designed as a reference test, the specificity and sensitivity of the LFIA were 98.2 and 84.8%, respectively. Excellent agreement between the results obtained by ELISA and the LFIA (κ = 0.851) was observed in this study. In addition, the agreement between the blood culture results and LFIA test is strong (κ = 0.658). The data presented in the study indicate that the LFIA test is a suitable tool for the serological surveillance of IC in the field or in poorly equipped laboratories.

Background Candiduria is common in hospitalized patients. Its management is limited because of inadequate understanding. Previous epidemiological studies based on culture assay have been limited to small study populations. Therefore, data collected by automated systems from a large target population are necessary for more comprehensive understanding of candiduria in hospitalized patients. Methods To determine the performance of the Sysmex UF-1000i in detecting candiduria, a cross-sectional study was designed and conducted. A total of 203 yeast-like cell (YLC)-positive and 127 negative samples were randomly chosen and subjected to microbiologic analysis. The receiver operating characteristic curve (ROC) was used to evaluate the ability of YLC counts as measured by the Sysmex UF1000i to predict candiduria. Urinalysis data from 31,648 hospitalized patients were retrospectively investigated, and statistical analysis was applied to the data collected. Results Using a cutoff value of 84.6 YLCs/µL, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the yeast like cell (YLC) counts to predict candiduria were 61.7%, 84.1%, 88.6% and 66.3%, respectively. C. glabrata (33.6%) and C. tropicalis (31.4%) were more prevalent than C. albicans (24.3%) in the present study. Of the investigated hospitalized patients, 509 (1.61%) were considered candiduria-positive. Age, gender and basic condition were associated with candiduria in hospitalized patients. In the ICU setting, urinary catheterization appeared to be the only independent risk factor contributing to candiduria according to our investigation. Although antibiotic therapy has been reported to be a very important risk factor, we could not confirm its significance in ICU candiduria patients because of excessive antibiotic usage in our hospital. Conclusions The YLC measured by Sysmex UF-1000i is a practical and convenient tool for clinical candiduria screening prior to microbiologic culture. Candiduria is common in hospitalized patients, and its incidence varies according to age, gender and the wards where it is isolated. Candiduria had no direct connection with mortality but might be considered a marker of seriously ill patients who need particular attention in the clinic.

BackgroundInfectious diseases emerge frequently in China, partly because of its large and highly mobile population. Therefore, a rapid and cost-effective pathogen screening method with broad coverage is required for prevention and control of infectious diseases. The availability of a large number of microbial genome sequences generated by conventional Sanger sequencing and next generation sequencing has enabled the development of a high-throughput high-density microarray platform for rapid large-scale screening of vertebrate pathogens.MethodsAn easy operating pathogen microarray (EOPM) was designed to detect almost all known pathogens and related species based on their genomic sequences. For effective identification of pathogens from EOPM data, a statistical enrichment algorithm has been proposed, and further implemented in a user-friendly web-based interface.ResultsUsing multiple probes designed to specifically detect a microbial genus or species, EOPM can correctly identify known pathogens at the species or genus level in blinded testing. Despite a lower sensitivity than PCR, EOPM is sufficiently sensitive to detect the predominant pathogens causing clinical symptoms. During application in two recent clinical infectious disease outbreaks in China, EOPM successfully identified the responsible pathogens.ConclusionsEOPM is an effective surveillance platform for infectious diseases, and can play an important role in infectious disease control.