Endoplasmic reticulum stress-mediated apoptosis is activated in intestines of mice with Trichinella spiralis infection.

Gastrointestinal helminth infection, including Trichinella spiralis, initiates a series of intestinal structural, cellular and physiological changes. Intestinal invasion is an important stage of trichinellosis because it determines the development and subsequent course of the disease and its consequences. Apoptosis mediated by endoplasmic reticulum stress (ERS) plays a key role in infectious diseases, but the effect of T. spiralis infection on inducing apoptosis in the small intestine has been neglected. We investigated apoptosis and changes in ERS-associated apoptosis molecules in the intestine of mice with T. spiralis infection. TUNEL staining and detection of the apoptotic marker cleaved caspase 3 revealed that apoptosis occurred in the mouse intestine at days 3 and 7 post-infection. The ER chaperone 78-kDa glucose-regulated protein (GRP78) was upregulated at days 3 and 7 post-infection. The ERS-associated apoptosis molecules C/EBP homologous protein, cleaved caspase 12 and c-Jun NH2-terminal kinase were upregulated at days 3 and 7, days 3, 7 and 10 and days 7 and 10 post-infection, respectively. Thus, apoptosis occurred in the intestine of mice with T. spiralis infection, and the ERS-mediated apoptosis pathway was activated by infection with this small intestine dwelling nematode.

Immuno-PCR for detection of Giardia lamblia cysts in water.

Giardia lamblia cysts at low concentrations were detected in water samples using a highly sensitive immunological-PCR (IPCR) method. Magnetic gold particles were precoated with monoclonal anti-Giardia antibodies, and Giardia lamblia cysts ranging from 1 to 100 cysts were diluted in 500 microL of water. A biotinylated detection antibody bound to the G. lamblia cysts was then linked by a streptavidin bridge to biotinylated Giardia-reporter DNA. After extensive washing, reporter DNA was released by denaturation, transferred to PCR tubes, amplified, electrophoresed, and visualized. An optimized immuno-PCR method detected as little as five G. lamblia cysts. To further evaluate the specificity and the clinical application of this IPCR assay for G. lamblia cysts, Entamoeba histolytica and Cryptosporidium parvum were also collected and detected by IPCR. The data demonstrated that this monoclonal antibody-based IPCR method is particularly useful for analysis of environmental water samples in which the densities of G. lamblia cysts is very low, and provides a platform capable of rapid screening of samples from drinking water, wells, rivers, lakes, and recreational swimming pools for trace levels of G. lamblia cysts.

Systemic cytokine profiles and splenic toll-like receptor expression during Trichinella spiralis infection.

Parasitic helminth and their products can suppress or modulate the host immune response for long-term survival and continued infection. Commonly, helminth can induce conditional T helper cell type 2 (Th2) response, regulatory T cell and cytokines, and altered function of antigen presentation cells by modulating toll-like receptors (TLRs). The helminth Trichinella spiralis establishes chronic infection in skeletal muscles of a wide range of mammalian hosts. We infected mice with T. spiralis and investigated Th1/Th2/Th17 cytokine profiles in serum and expression of TLRs and related signal molecules in spleen at various times post-infection. The infection evoked a mixed Th1/Th2 and inhibited Th17 immune response, with initial predominance of a Th1 response in intestine stage and subsequent predominance of a Th2 response in muscle stage. Different stages of infection had different impacts on the expression of TLRs and related signaling molecules. In the adult stage of infection, TLR1 and TLR4 were upregulated and the MyD88-dependent signal pathway was activated. The muscle larvae inhibited TLR4 and TRIF-dependent signal pathway. Our results implied that T. spiralis infection may regulate Th1/Th2/Th17 cytokine production through TLRs.

A highly sensitive immuno-PCR assay for detection of H5N1 avian influenza virus.

With an aim at detecting the ultra-low concentration of avian influenza virus (AIV), a highly sensitive hybrid assay based on immunology and polymerase chain reaction was developed. The TopYield microtiter plates were coated with ten-fold serial dilutions of H5N1 subtype AIV ranging from 10 EID(50 )ml(-1)~10(-4) EID(50) ml(-1),which was recognized by mouse anti-AIV H5 monoclonal antibody (MAb) that was directly linked with reporter DNA using a heterobifunctional cross-linker. After extensive washing, the reporter DNA including a BamH I-restriction site was released by a specific enzymatic restriction, then transferred to PCR tubes, amplified, and used as the signal for detection of AIV. Under the optimized condition, MAb-based immuno-PCR (IPCR) method could measure 100 µl of AIV H5N1 with 10(-4 )EID(50) ml(-1).To evaluate the sensitivity of IPCR, the same concentration and volume of AIV H5N1 were detected by conventional RT-PCR and sandwich ELISA. The results showed that IPCR had an approximately 1,000-fold improvement over the conventional ELISA, and a 100-fold enhancement compared with RT-PCR in detection sensitivity. To further evaluate the specificity of IPCR for AIV H5 subtype, the tracheal swab specimens, taken from chickens which were infected with H9N2, and the allantoic fluid from eggs inoculated by AIV H3N2, H7N1, H9N2, were detected by IPCR. To mimic clinical samples, pharyngeal-tracheal swab specimens were collected from healthy chickens and spiked with H5N1, H5N2, H5N3 for analysis by immuno-PCR. The results demonstrated that IPCR was a highly sensitive and specific assay for AIV H5, and could be applied to clinical detection for low amount of AIV H5 subtype. This MAb-based immuno-PCR method provided a platform capable of mass screening of clinical samples for AIV H5 subtype and could serve as a model for other immuno-PCR assays.

Development of Reverse Transcription Thermostable Helicase-Dependent DNA Amplification for the Detection of Tomato Spotted Wilt Virus.

A protocol for the reverse transcription-helicase-dependent amplification (RT-HDA) of isothermal DNA was developed for the detection of tomato spotted wilt virus (TSWV). Specific primers, which were based on the highly conserved region of the N gene sequence in TSWV, were used for the amplification of virus's RNA. The LOD of RT-HDA, reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP), and reverse transcriptase-polymerase chain reaction (RT-PCR) assays were conducted using 10-fold serial dilution of RNA eluates. TSWV sensitivity in RT-HDA and RT-LAMP was 4 pg RNA compared with 40 pg RNA in RT-PCR. The specificity of RT-HDA for TSWV was high, showing no cross-reactivity with other tomato and Tospovirus viruses including cucumber mosaic virus (CMV), tomato black ring virus (TBRV), tomato mosaic virus (ToMV), or impatiens necrotic spot virus (INSV). The RT-HDA method is effective for the detection of TSWV in plant samples and is a potential tool for early and rapid detection of TSWV.

Fuzzy State Transition and Kalman Filter Applied in Short-Term Traffic Flow Forecasting.

Traffic flow is widely recognized as an important parameter for road traffic state forecasting. Fuzzy state transform and Kalman filter (KF) have been applied in this field separately. But the studies show that the former method has good performance on the trend forecasting of traffic state variation but always involves several numerical errors. The latter model is good at numerical forecasting but is deficient in the expression of time hysteretically. This paper proposed an approach that combining fuzzy state transform and KF forecasting model. In considering the advantage of the two models, a weight combination model is proposed. The minimum of the sum forecasting error squared is regarded as a goal in optimizing the combined weight dynamically. Real detection data are used to test the efficiency. Results indicate that the method has a good performance in terms of short-term traffic forecasting.

First report of zoonotic Cryptosporidium spp., Giardia intestinalis and Enterocytozoon bieneusi in golden takins (Budorcas taxicolor bedfordi).

Genetic study of Cryptosporidium spp., Giardia intestinalis and Enterocytozoon bieneusi at species/assemblage/genotype/subtype level facilitates understanding their mechanical transmissions and underpins their control. A total of 191 fresh faecal samples were collected from golden takins in China and examined using multilocus sequence typing (MLST). Cryptosporidium spp. was detected in 15 faecal samples (7.9%), including Cryptosporidium parvum (2/15) and Cryptosporidium andersoni (13/15). MLST tool identified C. andersoni subtypes (A1, A4, A4, A1) and (A4, A4, A4, A1), and C. parvum gp60 gene subtype IId A19G1. The prevalence of G. intestinalis infection was 8.9% (17/191) and assemblage analysis identified 14 assemblage E and three assemblage B. Intra-variations were observed at triose phosphate isomerase (tpi), beta giardin (bg) and glutamate dehydrogenase (gdh) loci within the assemblage E, showing seven, three and three new subtypes in respective locus. Ten and one multilocus genotypes (MLGs) were present in assemblages E and B, respectively. E. bieneusi infection was positive in 14.7% (28/191) of the examined specimens, with three genotypes known (BEB6, D and I) and four novel internal transcribed spacer (ITS) genotypes (TEB1-TEB4). The present study revealed, for the first time, the presence of zoonotic C. parvum IId A19G1, G. intestinalis assemblage B and E. bieneusi genotype D and four novel genotypes in golden takins in China. These findings expand the host range of three zoonotic pathogens and have important implications for controlling cryptosporidiosis, giardiasis and microsporidiosis in humans and animals.