Microplastic ingestion by pelagic and demersal fish species from the Eastern Central Atlantic Ocean, off the Coast of Ghana

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordWe present data on the occurrence of microplastics in fish from the Guinea current region off Ghana's Coast. Frequency of occurrence of microplastics in the fish species followed the order: Sardinella maderensis (41%) > Dentex angolensis > (33%) > Sardinella aurita (26%). Mean numbers of microplastics ingested were 40.0 ± 3.8, 32.0 ± 2.7 and 25.7 ± 1.6 for S. maderensis, D. angolensis and S. aurita respectively. Industrially produced pellets were the most dominant (31%) microplastic type followed by microbeads (29%), burnt film plastics (22%) and unidentified fragments (9%). Microfibers (2%), threads (2%) and foams (1 and below 1 for S. maderensis. The findings of the study show the common occurrence of microplastics in fish stocks and pave the way for future studies on microplastics in this Region.Academy of Medical Science

New planetary systems from the Calan–Hertfordshire Extrasolar Planet Search

We report the discovery of eight new giant planets, and updated orbits for four known planets, orbiting dwarf and subgiant stars using the CORALIE, HARPS, and MIKE instruments as part of the Calan–Hertfordshire Extrasolar Planet Search. The planets have masses in the range 1.1–5.4 MJ’s, orbital periods from 40 to 2900 d, and eccentricities from 0.0 to 0.6. They include a double-planet system orbiting the most massive star in our sample (HD147873), two eccentric giant planets (HD128356b and HD154672b), and a rare 14 Herculis analogue (HD224538b). We highlight some population correlations from the sample of radial velocity detected planets orbiting nearby stars, including the mass function exponential distribution, confirmation of the growing body of evidence that low-mass planets tend to be found orbiting more metal-poor stars than giant planets, and a possible period–metallicity correlation for planets with masses >0.1 MJ, based on a metallicity difference of 0.16 dex between the population of planets with orbital periods less than 100 d and those with orbital periods greater than 100 d

Weakly haemolytic variants of Brachyspira hyodysenteriae newly emerged in Europe belong to a distinct subclade with unique genetic properties.

Brachyspira (B.) hyodysenteriae is widespread globally, and can cause mucohaemorrhagic colitis (swine dysentery, SD) with severe economic impact in infected herds. Typical strains of B. hyodysenteriae are strongly haemolytic on blood agar, and the haemolytic activity is believed to contribute to virulence in vivo. However, recently there have been reports of atypical weakly haemolytic isolates of B. hyodysenteriae (whBh). In this study, 34 European whBh and 82 strongly haemolytic isolates were subjected to comparative genomic analysis. A phylogenetic tree constructed using core single nucleotide polymorphisms showed that the whBh formed a distinct sub-clade. All eight genes previously associated with haemolysis in B. hyodysenteriae were present in the whBh. No consistent patterns of amino acid substitutions for all whBh were found in these genes. In contrast, a genome region containing six coding sequences (CDSs) had consistent nucleotide sequence differences between strongly and whBh isolates. Two CDSs were predicted to encode ABC transporter proteins, and a TolC family protein, which may have a role in the export of haemolysins from B. hyodysenteriae. Another difference in this region was the presence of three CDSs in whBh that are pseudogenes in strongly haemolytic isolates. One of the intact CDSs from whBh encoded a predicted PadR-like transcriptional repressor that may play a role in repression of haemolysis functions. In summary, a sub-clade of whBh isolates has emerged in Europe, and several genomic differences, that potentially explain the weakly haemolytic phenotype, were identified. These markers may provide targets for discriminatory molecular tests needed in SD surveillance

Neutrophil elastase and interleukin 17 expressed in the pig colon during Brachyspira hyodysenteriae infection synergistically with the pathogen induce increased mucus transport speed and production via mitogen-activated protein kinase 3

Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucoid hemorrhagic diarrhea and mucus layer changes. These changes are characterized by a disorganized mucus structure and massive mucus induction with de novo expression of MUC5AC and increased production of MUC2. To investigate the mechanisms behind this altered mucin environment, we quantified the mRNA levels of mucin pathway genes and factors from the immune system in the colons of infected and control pigs and observed upregulation of neutrophil elastase, SPDEF, FOXA3, MAPK3/ ERK1, IL-17A, IL-1 beta, IL-6, and IL-8 expression. In vitro, colonic mucus-producing mucosal surfaces were treated with these factors along with B. hyodysenteriae infection and analyzed for their effect on mucin production. Neutrophil elastase and infection synergistically induced mucus production and transport speed, and interleukin 17A (IL-17A) also had similar effects, in both the presence and absence of infection. A mitogen-activated protein kinase 3 (MAPK3)/extracellular signal-regulated kinase 1 (ERK1) inhibitor suppressed these effects. Therefore, we suggest that the SPDEF, FOXA3, and MAPK3/ERK1 signaling pathways are behind the transcriptional program regulating mucin biosynthesis in the colon during B. hyodysenteriae infection. In addition to furthering the knowledge on this economically important disease, this mechanism may be useful for the development of therapies aimed at conditions where enhancing mucus production may be beneficial, such as chronic inflammatory disorders of the colon