Atom-photon dressed states in a waveguide-QED system with multiple giant atoms.

We study the properties of bound states in waveguide-QED systems consisting of multiple giant atoms coupled to a coupled-resonator waveguide. Based on the general analytical expressions for these states and the corresponding energy spectra, we analyze in detail the threshold conditions for the appearance of bound states and the photon-mediated interactions between dressed atoms for different configurations. In addition, when multiple giant atoms are coupled to the waveguide, different types of interacting atomic chain can be obtained by manipulating the coupling configurations. Accordingly, the energy spectra of the bound states form metaband structures in the photonic band gaps. This makes the system a useful platform for quantum simulation and quantum information processing.

Single-photon switches, beam splitters, and circulators based on the photonic Aharonov-Bohm effect.

Single-photon devices such as switches, beam splitters, and circulators are fundamental components to construct photonic integrated quantum networks. In this paper, two V-type three-level atoms coupled to a waveguide are proposed to simultaneously realize these functions as a multifunctional and reconfigurable single-photon device. When both the two atoms are driven by the external coherent fields, the difference in the phases of the coherent driving induces the photonic Aharonov-Bohm effect. Based on the photonic Aharonov-Bohm effect and setting the two-atom distance to match the constructive or destructive interference conditions among photons travelling along different paths, a single-photon switch is achieved since the incident single photon can be controlled from complete transmission to complete reflection by adjusting the amplitudes and phases of the driving fields. When properly changing the amplitudes and phases of the driving fields, the incident photons are split equally into multiple components as a beam splitter operated with different frequencies. Meanwhile, the single-photon circulator with reconfigurable circulation directions can also be obtained.

First report of Echinococcus granulosus sensu stricto (G1) in Nigeria, West Africa.

Echinococcus granulosus sensu stricto is regarded to have the highest zoonotic potential of all Echinococcus taxa. Globally, human infection due to this species constitutes over 88.44% of the total cystic echinococcosis (CE) burden. Here, we report a CE infection in a Nigerian camel caused by E. granulosus G1 genotype. To the best of our knowledge, this report is the first encounter of the G1 genotype in the West Africa sub-region where the G6 genotype is reportedly prevalent, suggesting that the epidemiology of this highly zoonotic group could have a wider host range and distribution in the sub-region, and emphasizes the need for further investigation into the genetic diversity of Echinococcus spp. in Nigeria and across the sub-region.

[Advances in research on echinococcus shiquicus tapeworm].

Echinococcosis is an age-old disease that causes serious damage to the animal husbandry and the human health perennially. As a newly discovered species of Echinococus, E. shiquicus has the potential public health significance and could be a potential parasitic zoonosis. In this review, its etiology, life cycle, epidemiology, detection and diagnoses, public health etc. are discussed or summarized. Also, a series of comparisons among E. granulosus, E. multilocularis and E. shiquicus are made.

Transcriptomic analysis of the larva Taenia multiceps.

Taenia multiceps is an adult worm affiliated to Taeniidae family, Platyhelminthes phylum. The larvae of the parasite (Coenurus cerebralis) parasitic in the brain and spinal cord in domestic and wild ruminants or humans can led to a fatal central nervous system (CNS) disease. The aims of the present study were to define the transcriptome profiles of the larvae of T. multiceps by RNA-Seq approach, and to generate large functional gene datasets that could be used to predict the key molecular pathways linked to this cestode. Our results generated a total of 39,094,890 clean reads that were assembled from the sequence data in 90,833 contigs. Briefly, 70,253 unigenes with a mean length of 1492bp were formed. Based on a sequence similarity search against the databases (NR, Swissport, GO, COG, KEGG) using BLASTX with an E-value cutoff of 10-5, 40,465 of unigenes were identified as coding sequences (CDS) and 3261 were scanned by ESTScan. The present study carried out the transcriptome of the larval stage of T. multiceps, which provides a solid foundation for further studies in molecular biology and biochemistry as well as identification of candidate genes used in diagnosis and vaccine development.

Proteomic analysis of differentially expressed proteins in the three developmental stages of Trichinella spiralis.

Trichinella spiralis, an intracellular parasitic nematode, can cause severe foodborne zoonosis, trichinellosis. The life cycle of T. spiralis consists of adult (Ad), muscle larvae (ML) and newborn larvae (NBL). The protein profiles in different developmental stages of the parasite remain unknown. In the present study, proteins from lysates of Ad, ML and NBL were identified by isobaric tags for relative and absolute quantitation (iTRAQ). A total of 4691 proteins were identified in all the developmental stages, of which 1067 proteins were differentially expressed. The number of up-regulated proteins in NBL was higher than that of the other two groups. The protein profiles from Ad, ML and NBL were compared in pairs. The identified proteins were involved in various functions of T. spiralis life cycle, including sexual maturity, metabolism, utilization of carbohydrates, lipids and nucleotides, and other crucial developmental processes that occur at distinct stages. Further investigation of the transcriptional levels of major sperm protein, serine protease, zinc finger protein, etc. from the different protein profiles using quantitative RT-PCR showed identical results to the iTRAQ analysis. The differentially expressed proteins that are involved in developmental regulation and host-parasite interactions should be further studied.

Cloning and characterization of thioredoxin peroxidases from Trichinella spiralis.

The intracellular parasitic nematode, Trichinella spiralis, can initiate a high level of oxidative stress, especially during rapid growth and generative propagation phases. Thioredoxin peroxidases (TPXs) protect helminths against oxidative stress, but none has been identified in T. spiralis. Here, 3 members of the TPX family were cloned from T. spiralis muscle larvae (ML). The lengths of TsTPX ORFs were 747bp, 588bp and 594bp, respectively, and the deduced proteins predicted to contain AhpC-TSA and 1-cys Prx_C domains. Interestingly, qRT-PCR data showed that TsTPX genes were expressed in all three developmental stages of T. spiralis. The TsTPX2 and TsTPX3 genes were up-regulated in day 3 adults (Ad3) compared with newborn larvae (NBL) and ML (P<0.05); expression levels of the TsTPX1 gene in ML were higher compared with Ad3 and NBL amounts (P<0.05). After prokaryotic expression, the reactivity of rTsTPX proteins was assessed by Western-blotting: only rTsTPX1 was specifically recognized by T. spiralis infection sera from pigs. Enzyme catalytic experiments showed that rTsTPX proteins could deoxidize H2O2 in the presence of DTT, with the catalytic ability increasing with protein concentration and time.

Molecular characterization of enolase gene from Taenia multiceps.

Taenia multiceps is a cestode parasite with its larval stage, known as Coenurus cerebralis, mainly encysts in the central nervous system of sheep and other livestocks. Enolase is a key glycolytic enzyme and represents multifunction in most organisms. In the present study, a 1617bp full-length cDNA encoding enolase was cloned from T. multiceps and designated as TmENO. A putative encoded protein of 433 amino acid residues that exhibited high similarity to helminth parasites. The recombinant TmENO protein (rTmENO) showed the catalytic and plasminogen-binding characteristics after the TmENO was subcloned and expressed in the pET30a(+) vector. The TmENO gene was transcribed during the adult and larval stages and was also identified in both cyst fluid and as a component of the adult worms and the metacestode by western blot analysis. Taken together, our results will facilitate further structural characterization for TmENO and new potential control strategies for T. multiceps.

Molecular characterization of subcutaneous and muscular coenurosis of goats in United Arab Emirates.

Coenurosis is a parasitic disease caused by the larval stage of Taenia multiceps, which affects various ruminants species, particularly sheep and goats, and occasionally humans. In this note, non-cerebral coenurosis in goats with the goal to compare morphological and biomolecular characteristics is focused in order to determine if the non-cerebral specimens should be considered a new specie or a strain of T. multiceps. Three hundred goats slaughtered with macroscopic lesions due to the presence of metacestodes were examined in an abattoir in Dubai, United Arab Emirates in order to evaluate the presence of extra-cerebral coenuri. Forty-eight coenuri were found under the skin, between fasciae of the skeletal muscles, diaphragm and in the abdominal cavities. Morphologically, the examined non-cerebral coenuri recovered showed the same features reported by other authors for Coenurus cerebralis, but their location outside the central nervous system suggests that they may be a different strain or genetic variants of T. multiceps. Nine caprine coenuri were then processed for sequencing of mitochondrial partial COI (396 bp) and ND1 (471 bp) genes indicating that they had a pairwise distance of 1.0-1.3% and 2.4-4.1% compared with parasite' COI sequences from Italy (Tm1-Tm3 strains) and Erzurum strains of ovine origin, respectively; whereas it had 0.6-1.3% and 0.4-1.1% pairwise distance for ND1. Phylogenetic trees of their ND1 and COI sequences using the maximum composite likelihood method with MEGA showed that these nine parasites recovered in Emirates abattoir could be grouped into a new strain. In conclusion, morphological and molecular characterization of caprine coenurosis from Dubai, United Arab Emirates, shows that the specimens are significantly different from other strains or genotypes in COI sequence, which suggests that they should belong to different genotypes or strains of T. multiceps.

Ipr1 gene mediates RAW 264.7 macrophage cell line resistance to Mycobacterium bovis.

Tuberculosis caused by Mycobacterium bovis (M. bovis) seriously affects efficiency of animal production with impacts on public health as well. Effective programmes of prevention and eradication of M. bovis infection therefore are urgently needed. Intracellular pathogen resistance gene 1 (Ipr1) is well known to mediate innate immunity to Mycobacterium tuberculosis (MTB), but there are no reports as to whether Ipr1 can enhance the phagocytic ability of macrophage against M. bovis. In this investigation, RAW 264.7 macrophage was transduced with lentiviral vector carrying Ipr1 (named Lenti-Ipr1); transgenic cells were identified by RT-PCR and western blotting. Transgenic positive cells (R-Ipr1) were then infected with an M. bovis virulent strain, with non-transduced cells used as control. When cell proliferation, viability and apoptosis of the two groups were investigated, it was found that infected RAW 264.7 died by necrosis whereas R-Ipr1 underwent apoptosis. Furthermore, the numbers of intracellular bacteria in R-Ipr1 were lower than those in control cells (P < 0.05). To identify the role of Ipr1, we measured the genes of Casp3, Mcl-1 and NOS2A which associated with macrophage activation and apoptosis by real-time quantitative PCR. The results demonstrated that Ipr1 gene expression can enhance anti-M. bovis infection of macrophage. This establishes a basis for the future production of Ipr1-transgenic cattle to strengthen the tuberculosis resistance.

Molecular cloning of rhamnose-binding lectin gene and its promoter region from snakehead Channa argus.

Lectins are sugar-binding proteins that mediate pathogen recognition and cell-cell interactions. A rhamnose-binding lectin (RBL) gene and its promoter region have been cloned and characterized from snakehead Channa argus. From the transcription initiation site, snakehead rhamnose-binding lectin (SHL) gene extends 2,382 bp to the end of the 3' untranslated region (UTR), and contains nine exons and eight introns. The open reading frame (ORF) of the SHL transcript has 675 bp which encodes 224 amino acids. The molecular structure of SHL is composed of two tandem repeat carbohydrate recognition domains (CRD) with 35% internal identity. Analysis of the gene organization of SHL indicates that the ancestral gene of RBL may diverge and evolve by exon shuffling and gene duplication, producing new forms to play their own roles in various organisms. The characteristics of SHL gene 5' flanking region are the presence of consensus nuclear factor of interleukin 6 (NF-IL6) and IFN-gamma activation (GAS) sites. The results provide indirect evidence that up-regulation of SHL expression may be induced in response to inflammatory stimuli, such as lipopolysaccharide (LPS), interleukin 6 (IL-6), and interferon gamma (IFN-gamma). The transcript of SHL mRNA was expressed in the head kidney, posterior kidney, spleen, liver, intestine, heart, muscle, and ovary. No tissue-specific expressive pattern is different from reported STLs, WCLs, and PFLs, suggesting that different types of RBLs exist in species-specific fish that have evolved and adapted to their surroundings.