Real-Time PCR-Based Methods for Detection of Hepatitis E Virus in Pork Products: A Critical Review.

Standard methods for detection of hepatitis A virus and norovirus in at-risk foodstuffs are available, but currently there is no standard method for detection of hepatitis E virus (HEV) in pork products or other foods that can be contaminated with the virus. Detection assays for HEV are mainly based on nucleic acid amplification, particularly the reverse transcription polymerase chain reaction (RTPCR) in real-time format. RTPCR-based methods can be sensitive and specific, but they require a suite of controls to verify that they have performed correctly. There have been several RTPCR methods developed to detect HEV in pork products, varying in details of sample preparation and RTPCR target sequences. This review critically discusses published HEV detection methods, with emphasis on those that have been successfully used in subsequent studies and surveys. RTPCR assays have been used both qualitatively and quantitatively, although in the latter case the data acquired are only reliable if appropriate assay calibration has been performed. One particular RTPCR assay appears to be ideal for incorporation in a standard method, as it has been demonstrated to be highly specific and sensitive, and an appropriate control and calibration standard is available. The review focuses on the detection of HEV in pork products and similar foodstuffs (e.g., boar). The information may be useful to inform standardisation activities.

Transcriptional Response of Ovine Lung to Infection with Jaagsiekte Sheep Retrovirus.

Jaagsiekte sheep retrovirus (JSRV) is the etiologic agent of ovine pulmonary adenocarcinoma (OPA), a neoplastic lung disease of sheep. OPA is an important economic and welfare issue for sheep farmers and a valuable naturally occurring animal model for human lung adenocarcinoma. Here, we used RNA sequencing to study the transcriptional response of ovine lung tissue to infection by JSRV. We identified 1,971 ovine genes differentially expressed in JSRV-infected lung compared to noninfected lung, including many genes with roles in carcinogenesis and immunomodulation. The differential expression of selected genes was confirmed using immunohistochemistry and reverse transcription-quantitative PCR. A key finding was the activation of anterior gradient 2, yes-associated protein 1, and amphiregulin in OPA tumor cells, indicating a role for this oncogenic pathway in OPA. In addition, there was differential expression of genes related to innate immunity, including genes encoding cytokines, chemokines, and complement system proteins. In contrast, there was little evidence for the upregulation of genes involved in T-cell immunity. Many genes related to macrophage function were also differentially expressed, reflecting the increased abundance of these cells in OPA-affected lung tissue. Comparison of the genes differentially regulated in OPA with the transcriptional changes occurring in human lung cancer revealed important similarities and differences between OPA and human lung adenocarcinoma. This study provides valuable new information on the pathogenesis of OPA and strengthens the use of this naturally occurring animal model for human lung adenocarcinoma.IMPORTANCE Ovine pulmonary adenocarcinoma is a chronic respiratory disease of sheep caused by jaagsiekte sheep retrovirus (JSRV). OPA is a significant economic problem for sheep farmers in many countries and is a valuable animal model for some forms of human lung cancer. Here, we examined the changes in host gene expression that occur in the lung in response to JSRV infection. We identified a large number of genes with altered expression in infected lung, including factors with roles in cancer and immune system function. We also compared the data from OPA to previously published data from human lung adenocarcinoma and found a large degree of overlap in the genes that were dysregulated. The results of this study provide exciting new avenues for future studies of OPA and may have comparative relevance for understanding human lung cancer.

Novel host-related virulence factors are encoded by squirrelpox virus, the main causative agent of epidemic disease in red squirrels in the UK.

Squirrelpox virus (SQPV) shows little evidence for morbidity or mortality in North American grey squirrels (Sciurus carolinensis), in which the virus is endemic. However, more recently the virus has emerged to cause epidemics with high mortality in Eurasian red squirrels (S. vulgaris) in Great Britain, which are now threatened. Here we report the genome sequence of SQPV. Comparison with other Poxviridae revealed a core set of poxvirus genes, the phylogeny of which showed SQPV to be in a new Chordopoxvirus subfamily between the Molluscipoxviruses and Parapoxviruses. A number of SQPV genes were related to virulence, including three major histocomaptibility class I homologs, and one CD47 homolog. In addition, a novel potential virulence factor showing homology to mammalian oligoadenylate synthetase (OAS) was identified. This family of proteins normally causes activation of an endoribonuclease (RNaseL) within infected cells. The putative function of this novel SQPV protein was predicted in silico.

Preliminary characterisation of Pentlands paramyxovirus-1, -2 and -3, three new paramyxoviruses of rodents.

A paramyxovirus was discovered by chance during the primary culture of grey squirrel (Sciurus carolinensis) kidney cells from the UK. Amplification, sequencing and phylogenetic analysis of part of the genome encoding a region of the RNA polymerase (L gene) confirmed that the virus was a member of the Paramyxovirinae subfamily, but that it did not partition with any of the currently recognised paramyxovirus genera and instead segregated with the unclassified rodent viruses, J-virus, Beilong virus and Tailam virus as well as paramyxoviruses recently detected in rodents in Africa. A subsequent examination of kidney samples from red squirrels (Sciurus vulgaris) revealed that they too harboured a paramyxovirus, but sequence analysis of the corresponding region of the L gene revealed that it was approximately 67% identical to the grey squirrel virus, suggesting the presence of a second species of virus. In addition, one of the red squirrels examined harboured a second virus with approximately 69% identity to the grey squirrel virus, but only approximately 63% identity to the other red squirrel viruses, signifying the presence of a third species of paramyxovirus. In a sample of 22 red and grey squirrels 68% of those examined were found to harbour virus suggesting that paramyxovirus infection in squirrels may be common within the UK.

Design and evaluation of novel primers for the detection of genes encoding diverse enzymes of methylotrophy and autotrophy.

The phylogenetic significance of the diversity of key enzymes of methylotrophic and autotrophic metabolism is discussed. Primers for these key enzymes were designed using gene sequences encoding methanol dehydrogenase (mxaF; using subsets from database sequences for 22 Bacteria), hydroxypyruvate reductase (hpr; 36 sequences), methylamine dehydrogenase (mauA; 12 sequences), methanesulfonate monooxygenase (msmA; four sequences), and the ccbL and cbbM genes of ribulose bisphosphate carboxylase (26 and 23 sequences). These were effective in amplifying the correct gene products for the target genes in reference organisms and in test organisms not previously shown to contain the genes, as well as in some methylotrophic Proteobacteria isolated from the human mouth. The availability of the new primers increases the probability of detecting diverse examples of the genes encoding these key enzymes both in natural populations and in isolated bacterial strains.

Connectivity, small islands and large distances: the Cellana strigilis limpet complex in the Southern Ocean.

The Southern Ocean contains some of the most isolated islands on Earth, and fundamental questions remain regarding their colonization and the connectivity of their coastal biotas. Here, we conduct a genetic investigation into the Cellana strigilis (limpet) complex that was originally classified based on morphological characters into six subspecies, five of which are endemic to the New Zealand (NZ) subantarctic and Chatham islands (44-52°S). Previous genetic analyses of C. strigilis from six of the seven island groups revealed two lineages with little or no within-lineage variation. We analysed C. strigilis samples from all seven island groups using two mitochondrial (COI and 16S), one nuclear (ATPase ß) and 58 loci from four randomly amplified polymorphic DNA markers (RAPDs) and confirmed the existence of two distinct lineages. The pronounced genetic structuring within each lineage and the presence of private haplotypes in individual islands are the result of little genetic connectivity and therefore very high self-recruitment. This study supports the significance of the subantarctic islands as refugia during the last glacial maximum and adds to the knowledge of contemporary population connectivity among coastal populations of remote islands in large oceans and the distance barrier to gene flow that exists in the sea (despite its continuous medium) for most taxa.

Facultative methylotrophs from the human oral cavity and methylotrophy in strains of Gordonia, Leifsonia, and Microbacterium.

We show that bacteria with methylotrophic potential are ubiquitous in the human mouth microbiota. Numerous strains of Actinobacteria (Brevibacterium, Gordonia, Leifsonia, Microbacterium, Micrococcus, Rhodococcus) and Proteobacteria (Achromobacter, Klebsiella, Methylobacterium, Pseudomonas, Ralstonia) were isolated, and one strain of each of the eleven genera was studied in detail. These strains expressed enzymes associated with methylotrophic metabolism (methanol, methylamine, and formate dehydrogenases), and the assimilation of one-carbon compounds by the serine pathway (hydroxypyruvate reductase). Methylotrophic growth of the strains was enhanced by the addition of glass beads to cultures, suggesting that they may naturally occur in biofilms in the mouth. This is the first report of Gordonia, Leifsonia, and Rhodococcus being present in the mouth and of the unequivocal demonstration for the first time of the methylotrophic potential of strains of Gordonia, Leifsonia, and Microbacterium.

Purification and characterization of dimethylsulfide monooxygenase from Hyphomicrobium sulfonivorans.

Dimethylsulfide (DMS) is a volatile organosulfur compound which has been implicated in the biogeochemical cycling of sulfur and in climate control. Microbial degradation is a major sink for DMS. DMS metabolism in some bacteria involves its oxidation by a DMS monooxygenase in the first step of the degradation pathway; however, this enzyme has remained uncharacterized until now. We have purified a DMS monooxygenase from Hyphomicrobium sulfonivorans, which was previously isolated from garden soil. The enzyme is a member of the flavin-linked monooxygenases of the luciferase family and is most closely related to nitrilotriacetate monooxygenases. It consists of two subunits: DmoA, a 53-kDa FMNH2-dependent monooxygenase, and DmoB, a 19-kDa NAD(P)H-dependent flavin oxidoreductase. Enzyme kinetics were investigated with a range of substrates and inhibitors. The enzyme had a K(m) of 17.2 (± 0.48) µM for DMS (k(cat) = 5.45 s⁻¹) and a V(max) of 1.25 (± 0.01) µmol NADH oxidized min⁻¹ (mg protein⁻¹). It was inhibited by umbelliferone, 8-anilinonaphthalenesulfonate, a range of metal-chelating agents, and Hg²(+), Cd²(+), and Pb²(+) ions. The purified enzyme had no activity with the substrates of related enzymes, including alkanesulfonates, aldehydes, nitrilotriacetate, or dibenzothiophenesulfone. The gene encoding the 53-kDa enzyme subunit has been cloned and matched to the enzyme subunit by mass spectrometry. DMS monooxygenase represents a new class of FMNH2-dependent monooxygenases, based on its specificity for dimethylsulfide and the molecular phylogeny of its predicted amino acid sequence. The gene encoding the large subunit of DMS monooxygenase is colocated with genes encoding putative flavin reductases, homologues of enzymes of inorganic and organic sulfur compound metabolism, and enzymes involved in riboflavin synthesis.

Nurse and patient activities and interaction on psychiatric inpatients wards: a literature review.

BACKGROUND: Despite major developments in community mental health services, inpatient care remains an important yet costly part of the service system and patients who are admitted frequently spend a long period of time in hospital. It is, therefore, crucial to have a good understanding of activities that take place on inpatient wards. OBJECTIVE: To review studies that have measured nursing and patient activity and interaction on psychiatric inpatient wards. DATA SOURCES AND REVIEW METHODS: This literature review was performed by searching electronic databases and hand-checking reference lists. RESULTS: The review identified 13 relevant studies. Most used observational methods and found that at best 50% of staff time is spent in contact with patients, and very little time is spent delivering therapeutic activities. Studies also showed that patients spend substantial time apart from staff or other patients. CONCLUSION: On inpatient psychiatric wards, evidence over 35 years has found little patient activity or patient social engagement. The reasons for this trend and recommendations for the future are discussed.

Further evidence to justify reassignment of Mycoplasma mycoides subspecies mycoides Large Colony type to Mycoplasma mycoides subspecies capri.

Analysis, using the polymerase chain reaction (PCR), restriction enzyme endonuclease analysis (REA), protein profile patterns, random amplification of polymorphic DNA (RAPD) fingerprinting, 16S rRNA gene sequencing and antisera growth inhibition tests, of 22 strains of Mycoplasma mycoides subsp. mycoides Large Colony type (MmmLC) and eight strains of M. mycoides subsp. capri (Mmc) are presented, along with a summary of comparative data from the literature for over 100 strains, all of which supports the reclassification of the MmmLC and Mmc strains into the single subspecies, M. mycoides subspecies capri.

Kinetics of substrate oxidation and hydrogen peroxide production by Mycoplasma mycoides subsp. mycoides Large Colony (LC) type and Mycoplasma mycoides subsp. capri.

Mycoplasma mycoides subsp. mycoides Large Colony (LC) type is a pathogen of goats causing contagious agalactia and respiratory disease, found on all continents where small ruminants are kept. It shares close genetic characteristics with M. mycoides subsp. capri. Substrate oxidation by 22 strains of M. mycoides subsp. mycoides LC from nine countries was compared with that of eight strains of M. mycoides subsp. capri from five countries. There was considerable similarity in the substrates used, but substrate saturation coefficients (K(s)) varied for different substrates. Substrate utilization patterns and K(s) values did not (1) significantly differentiate the LC strains from each other, (2) show any correlation with geographical origin, or (3) distinguish the LC strains from the capri strains. These results support previous studies justifying the reclassification of these subspecies as a single species.

Novel methylotrophic bacteria isolated from the River Thames (London, UK).

Enrichment and elective culture for methylotrophs from sediment of the River Thames in central London yielded a diversity of pure cultures representing several genera of Gram-negative and Gram-positive bacteria, which were mainly of organisms not generally regarded as typically methylotrophic. Substrates leading to successful isolations included methanol, monomethylamine, dimethylamine, trimethylamine, methanesulfonate and dimethylsulfone. Several isolates were studied in detail and shown by their biochemical and morphological properties and 16S rRNA gene sequencing to be Sphingomonas melonis strain ET35, Mycobacterium fluoranthenivorans strain DSQ3, Rhodococcus erythropolis strain DSQ4, Brevibacterium casei strain MSQ5, Klebsiella oxytoca strains MMA/F and MMA/1, Pseudomonas mendocina strain TSQ4, and Flavobacterium sp. strains MSA/1 and MMA/2. The results show that facultative methylotrophy is present across a wide range of Bacteria, suggesting that turnover of diverse C(1)-compounds is of much greater microbiological and environmental significance than is generally thought. The origins of the genes encoding the enzymes of methylotrophy in diverse heterotrophs need further study, and could further our understanding of the phylogeny and antiquity of methylotrophic systems.

Proposal that the strains of the Mycoplasma ovine/caprine serogroup 11 be reclassified as Mycoplasma bovigenitalium.

This proposal is our response to the recommendation of the International Committee on Systematics of Prokaryotes (Subcommittee on the taxonomy of Mollicutes) that we 'write a proposal to classify Mycoplasma bovigenitalium and ovine/caprine serogroup 11 as a single species'. Physiological and phylogenetic comparisons between 27 strains of M. bovigenitalium and Mycoplasma serogroup 11 showed that (i) growth and patterns of organic acid substrate use completely overlapped among strains; (ii) all had lipase and phosphatase activities; (iii) the strains were indistinguishable in their SDS-PAGE whole-cell protein profiles, which differed from five other species; (iv) strains were indistinguishable in immunoblotting of cell proteins and cross-reactivity in ELISA, but differed from other Mycoplasma species; (v) DNA-DNA hybridization did not distinguish between the two groups, and (vi) comparison of 16S and 23S rRNA gene sequences of ten strains of Mycoplasma serogroup 11 and six strains of M. bovigenitalium showed that they shared 98-100% similarity across all strains tested, but only 86-95% to other Mycoplasma species. Strains of the Mycoplasma ovine/caprine serogroup 11 must therefore be reassigned as Mycoplasma bovigenitalium.

Reassessment of the phylogenetic relationships of Thiomonas cuprina.

The published sequence of the 16S rRNA gene of Thiomonas cuprina strain Hö5 (=DSM 5495T) (GenBank accession no. U67162) was found to be erroneous. The 16S rRNA genes from the type strain held by the DSMZ since 1990 (DSM 5495T=NBRC 102145T) and strain Hö5 maintained frozen in the Universität Regensburg for 23 years (=NBRC 102094) were sequenced and found to be identical, but to show no significant similarity to the U67162 sequence. This also casts some doubt on the previously published 5S and 23S rRNA gene sequences (GenBank accession nos U67171 and X75567). The correct 16S rRNA gene sequence showed 99.8% identity to those from Thiomonas delicata NBRC 14566T and 'Thiomonas arsenivorans' DSM 16361. The properties of these three species are re-evaluated, and emended descriptions are provided for the genus Thiomonas and the species Thiomonas cuprina.

A molecular phylogeny of the marine mussel genus Perna (Bivalvia: Mytilidae) based on nuclear (ITS1&2) and mitochondrial (COI) DNA sequences.

A molecular phylogeny is presented for marine mussels of the genus Perna, based on nuclear (ITS1,ITS2) and mitochondrial (COI) DNA sequence data. The three generally recognised species (Perna viridis, Perna perna and Perna canaliculus) and one putative species (Perna picta) were each sampled from several locations within their known geographic distributions. A range of phylogenetic analyses was used to investigate the current taxonomic assignments, evolutionary relationships and the biogeographical history of the genus. The different analyses produced similar, well supported topologies and verified the monophyly of the genus with respect to five mytilid outgroup species. P. perna (Atlantic), P. viridis (Indo-West Pacific), and P. canaliculus (New Zealand) each formed distinct clades, confirming their specific status. Putative P. picta from North Africa clustered within the P. perna clade and is not regarded as a separate species. P. perna and P. canaliculus were the most closely related of the three species. Possible biogeographic explanations for the present species distributions are evaluated.

Confirmation of Thiomonas delicata (formerly Thiobacillus delicatus) as a distinct species of the genus Thiomonas Moreira and Amils 1997 with comments on some species currently assigned to the genus.

The transfer of Thiobacillus delicatus to the genus Thiomonas as a distinct species, Thiomonas delicata (type strain NBRC 14566T), is confirmed by its morphological and physiological properties, DNA-DNA hybridization and the grouping of its 16S rRNA gene sequence with those of other species of the genus. An emended formal description of Thiomonas delicata is given. The status of Thiomonas cuprina DSM 5495T as a member of the genus is reconsidered.

Redefining Paracoccus denitrificans and Paracoccus pantotrophus and the case for a reassessment of the strains held by international culture collections.

An outline of the current taxonomic diversity of the genus Paracoccus is presented. A definitive summary is given of the valid type strains of Paracoccus denitrificans and Paracoccus pantotrophus and of culture collection strains that can be assigned to these species. The case is established for a critical reassessment of the P. denitrificans strains held by international culture collections, to ensure that they are assigned to the correct species.