Catalytic Intermolecular Deoxygenative Coupling of Carbonyl Compounds with Alkynes by a Cp*Mo(II)-Catalyst.

Carbonyl is highly accessible and acts as an essential functional group in chemical synthesis. However, the direct catalytic deoxygenative functionalization of carbonyl compounds via a putative metal carbene intermediate is a formidable challenge due to the requirement of a high activation energy for the cleavage of strong C═O double bonds. Here, we report a class of bench stable and readily available Cp*Mo(II)-complexes as efficient deoxygenation catalysts that could catalyze the direct intermolecular deoxygenative coupling of carbonyl compounds with alkynes. Enabled by this powerful Cp*Mo(II)-catalyst, various valuable heteroarenes (10 different classes) were obtained in generally good yields and remarkable chemo- and regioselectivities. Mechanistic studies suggested that this reaction might proceed via a sequence of C═O double bonds cleavage, carbene-alkyne metathesis, cyclization, and aromatization processes. This strategy not only provided a general catalytic platform for the rapid preparation of heteroarenes but also opened a new window for the applications of Cp*Mo(II)-catalysts in organic synthesis.

Assessment of probiotic adhesion and inhibitory effect on Escherichia coli and Salmonella adhesion.

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73-55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application.

Changes in TFG gene expression in bovine leucocytes transformed by Theileria annulata.

Theileria annulata schizont-infected host cells in culture in vitro show unlimited proliferation similar to tumor cells; thus far, T. annulata and T. parva are the only eukaryotes that have been found to transform mammalian cells (immortalized). The transformation of these cells is reversible; when the parasite is eliminated in transformed cells by buparvaquone (BW720c), the host cells show normal growth and apoptosis. TFG is a tropomyosin-receptor kinase fused gene that is conserved among many species and is an important proto-oncogene. In this study, the bovine TFG gene was amplified by PCR from the cDNA of T. annulata schizont-transformed cells, cloned into the pGEX-4T-1 vector and expressed in Escherichia coli BL21 (DE3). After purification, the fusion protein was injected into rabbits to produce polyclonal antibodies. Using T. annulata-transformed cells together with BW720c treatment to kill the parasite, we aimed to identify changes in TFG gene expression by real-time PCR and Western blotting. The results showed that the bovine TFG gene was ~582 bp in size; SDS-PAGE analysis showed that the fusion protein was expressed in BL21 (DE3) cells with a molecular mass of 48 kD, and Western blotting indicated that the polyclonal antibodies could react with bovine TFG proteins from T. annulata-transformed cells and showed high specificity. Compared with that in the control group, the transcription level of the host TFG gene decreased significantly in the BW720c test group, and the expression of host tumor-related TFG protein decreased sharply after 72 h of drug treatment, suggesting that the TFG protein expression in transformed cells was directly related to T. annulata. This finding laid a foundation for further study on the interaction between T. annulata and host cells.

Metabolomic profiling of bovine leucocytes transformed by Theileria annulata under BW720c treatment.

BACKGROUND: When Theileria annulata infects host cells, it undertakes unlimited proliferation as tumor cells. Although the transformed cells will recover their limited reproductive characteristics and enter the apoptosis process after treatment with buparvaquone (BW720c), the metabolites and metabolic pathways involved are not clear. METHODS: The transformed cells of T. annulata were used as experimental materials, and the buparvaquone treatment group and DMSO control group were used. Qualitative and quantitative analysis was undertaken of 36 cell samples based on the LC-QTOF platform in positive and negative ion modes. The metabolites of the cell samples after 72 h of drug treatment were analyzed, as were the different metabolites and metabolic pathways involved in the BW720c treatment. Finally, the differential metabolites and metabolic pathways in the transformed cells were found. RESULTS: A total of 1425 metabolites were detected in the negative ion mode and 1298 metabolites were detected in the positive ion mode. After drug treatment for 24 h, 48 h, and 72 h, there were 56, 162, and 243 differential metabolites in negative ion mode, and 35, 121, and 177 differential metabolites in positive ion mode, respectively. These differential metabolites are mainly concentrated on various essential amino acids. CONCLUSION: BW720c treatment induces metabolic disturbances in T. annulata-infected cells by regulating the metabolism of leucine, arginine, and L-carnitine, and induces host cell apoptosis.

First report on the occurance of intestinal Entamoeba spp. In pigs In China.

Three Entamoeba spp. including E. suis, zoonotic E. polecki, and E. histolytica, have been described in pigs to date. However, little is known about the molecular epidemiology of these neglected parasites in pigs globally. In this study we surveyed the occurrence and molecular epidemiology of porcine Entamoeba spp. in pigs in eastern China and evaluated their zoonotic potential. Five hundred fresh fecal samples, collected from seven pig farms in Anhui province, eastern China,were examined for the presence of E. histolytica, E. suis, and E. polecki ST1 and ST3 infections by a combination of nested PCR targeting the small subunit ribosomal DNA gene and subsequent sequencing.The overall occurrence of Entamoeba spp. was 45.8% (229/500). Infection with E. polecki ST1 (38.2%; 191/500) was the most common, followed by E. polecki ST3 (10.0%; 50/500), and E. suis (0.8%; 4/500). No E. histolytica infection was detected. Double infections with E. polecki ST1 and E. suis, and with E. polecki ST1 and ST3 were found in two (0.4%) and 14 (2.8%) samples, respectively. No age predisposition to infection with Entamoeba spp. was observed. PCR and subsequent sequencing confirmed the validity and feasibility of the nested PCR method used in this study in identifying species/subtypes of porcine Entamoeba spp.This is the first report to describe the occurrence and molecular epidemiology of Entamoeba species in pigs in China. The presence of two zoonotic E. polecki subtypes implies that pigs can be reservoirs for human E. polecki infections. More studiess are needed to better understand the transmission and public health significance of porcine Entamoeba spp.

Molecular evidence for piroplasms in wild Reeves' muntjac (Muntiacus reevesi) in China.

DNA from liver samples of 17 free-ranging wild Reeves' muntjac (Muntiacus reevesi) was used for PCR amplification of piropalsm 18S rRNA gene. Of 17 samples, 14 (82.4%) showed a specific PCR product which were cloned and sequenced. BLAST analysis of the sequences obtained showed similarities to Babesia sp., Theileria capreoli, Theileria uilenbergi and Theileria sp. BO302-SE. Phylogenetic analysis showed that the Babesia sp. detected in the present study was distantly separated from known Babesia species of wild and domestic animals. Six sequences showed 100% similarity to T. capreoli while five sequences were separated from all known Theileria species and constituted an independent clade with Theileria sp. BO302-SE derived from roe deer in Italy; two sequences were close to T. uilenbergi with 97% similarity. This is the first description of hemoparasite infection in free-ranging wild Reeves' muntjac in China. Our results indicate that wild Reeves' muntjac may play an important reservoir role for hemoparasites.

Polymorphism analysis of Chinese Theileria sergenti using allele-specific polymerase chain reaction of the major piroplasm surface protein gene.

Theileria sergenti is a tick-borne parasite found in many parts of the world. The major piroplasm surface protein (MPSP), a conserved protein in all Theileria species, has been used as a marker for epidemiological and phylogenetic studies of benign Theileria species. In this study, Chinese species of T. sergenti were characterized by allele-specific polymerase chain reaction (PCR) and DNA sequence analysis of the MPSP gene. Using universal or allele-specific primer sets for PCR amplification of the MPSP gene, 98 of 288 cattle blood samples, collected from 6 provinces in China, were found to be positive. Among the positive samples, only 3 allelic MPSP gene types (Chitose [C]-, Ikeda [I]-, and buffeli [B]-type) were successfully amplified. Moreover, the results revealed that the majority of the parasites sampled in this study were C- and I-type (prevalence of 84 and 69%, respectively), whereas the B-type was less common (prevalence of 36%). Co-infections with C-, I-, and B-type T. sergenti also were found. An additional known allele, Thai-type, was not detected. Phylogenetic analysis based on the MPSP gene sequences, including 3 standard stocks generated in the laboratory ( T. sergenti Wenchuan, T. sergenti Ningxian, and T. sergenti Liaoyang), revealed that the isolates of Chinese sergenti were comprised of at least 4 allelic MPSP gene types, i.e., C-, I-, B1-, and B2-type, and these parasites with 6 MPSP types 1-5 and 7 were present in China.