High Prevalence and High Incidence of Coinfection with Hepatitis B,Hepatitis C,and Syphilis and Low Rate of Effective Vaccination against Hepatitis B in HIV-Positive Men Who Have Sex with Men with Known Date of HIV Seroconversion in Germany

Objectives

Men who have sex with men (MSM) are at higher risk for coinfection with hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis than the general population. HIV infection and these coinfections accelerate disease progression reciprocally. This study evaluated the prevalence and incidence of these coinfections in HIV1-positive MSM in Germany.

Materials and Methods

As part of a nationwide, multicenter, prospective cohort study of HIV-infected MSM, plasma samples collected yearly were screened for HBsAg and antibodies to HBc, HBs, HCV, and syphilis. Samples with indications of active HBV or HCV infection were confirmed by polymerase chain reaction. Prevalence and incidence of each infection and incidence rates per study participant were calculated, and incidences over 4-year time intervals compared.

Results

This study screened 5,445 samples from 1,843 MSM. Median age at HIV seroconversion was 33 years. Prevalences of active, cleared, and occult HBV, and of active/cleared HCV were 1.7%, 27.1%, 0.2%, and 8.2%, respectively, and 47.5% had been effectively vaccinated against HBV. Prevalence of antibodies to Treponema pallidum and of triple or quadruple sexually transmitted infections (STIs) were 39.6% and 18.9%, respectively. Prevalence of STI, cleared HBV, HBV vaccination, and history of syphilis differed significantly among age groups. Incidences of HBV, HCV, and syphilis were 2.51, 1.54, and 4.06 per 100 person-years, respectively. Incidences of HCV and syphilis increased over time. HCV incidence was significantly higher in MSM coinfected with syphilis and living in Berlin, and syphilis incidence was significantly higher for MSM living in Berlin.

Discussion

Despite extensive HBV vaccination campaigns, fewer than 50% of screened MSM were effectively vaccinated, with a high proportion of HIV-positive MSM coinfected with HBV. High rates of STI coinfections in HIV-positive MSM and increasing incidences emphasize the need for better tailored campaigns for HBV vaccination and STI prevention.     

Behavioural Assessment of the A2a/NR2B Combination in the Unilateral 6-OHDA-Lesioned Rat Model: A New Method to Examine the Therapeutic Potential of Non-Dopaminergic Drugs

In Parkinson’s disease (PD), dopaminergic therapies are often associated with the development of motor complications. Attention has therefore been focused on the use of non-dopaminergic drugs. This study developed a new behavioural method capable of demonstrating the added value of combining adenosinergic and glutamatergic receptor antagonists in unilateral 6-OHDA lesioned rats. Rats were dosed orally with Tozadenant, a selective A_2A receptor antagonist, and three different doses of Radiprodil, an NR2B-selective NMDA receptor antagonist. The drugs were given alone or in combination and rats were placed in an open-field for behavioural monitoring. Video recordings were automatically analysed. Five different behaviours were scored: distance traveled, ipsi- and contraversive turns, body position, and space occupancy. The results show that A_2A or NR2B receptor antagonists given alone or in combination did not produce enhanced turning as observed with an active dose of L-Dopa/benserazide. Instead the treated rats maintained a straight body position, were able to shift from one direction to the other and occupied a significantly larger space in the arena. The highest “Tozadenant/Radiprodil” dose combination significantly increased all five behavioural parameters recorded compared to rats treated with vehicle or the same doses of the drugs alone. Our data suggest that the A_2A/NR2B antagonist combination may be able to stimulate motor activity to a similar level as that achieved by L-Dopa but in the absence of the side-effects that are associated with dopaminergic hyperstimulation. If these results translate into the clinic, this combination could represent an alternative symptomatic treatment option for PD.     

Characterization of the Newly Isolated Lytic Bacteriophages KTN6 and KT28 and Their Efficacy against Pseudomonas aeruginosa Biofilm

We here describe two novel lytic phages, KT28 and KTN6, infecting Pseudomonas aeruginosa, isolated from a sewage sample from an irrigated field near Wroclaw, in Poland. Both viruses show characteristic features of Pbunalikevirus genus within the Myoviridae family with respect to shape and size of head/tail, as well as LPS host receptor recognition. Genome analysis confirmed the similarity to other PB1-related phages, ranging between 48 and 96%. Pseudomonas phage KT28 has a genome size of 66,381 bp and KTN6 of 65,994 bp. The latent period, burst size, stability and host range was determined for both viruses under standard laboratory conditions. Biofilm eradication efficacy was tested on peg-lid plate assay and PET membrane surface. Significant reduction of colony forming units was observed (70-90%) in 24 h to 72 h old Pseudomonas aeruginosa PAO1 biofilm cultures for both phages. Furthermore, a pyocyanin and pyoverdin reduction tests reveal that tested phages lowers the amount of both secreted dyes in 48-72 h old biofilms. Diffusion and goniometry experiments revealed the increase of diffusion rate through the biofilm matrix after phage application. These characteristics indicate these phages could be used to prevent Pseudomonas aeruginosa infections and biofilm formation. It was also shown, that PB1-related phage treatment of biofilm caused the emergence of stable phage-resistant mutants growing as small colony variants.     

Expression of parasite genetic variation changes over the course of infection: implications of within-host dynamics for the evolution of virulence

How infectious disease agents interact with their host changes during the course of infection and can alter the expression of disease-related traits. Yet by measuring parasite life-history traits at one or few moments during infection, studies have overlooked the impact of variable parasite growth trajectories on disease evolution. Here we show that infection-age-specific estimates of host and parasite fitness components can reveal new insight into the evolution of parasites. We do so by characterizing the within-host dynamics over an entire infection period for five genotypes of the castrating bacterial parasite Pasteuria ramosa infecting the crustacean Daphnia magna. Our results reveal that genetic variation for parasite-induced gigantism, host castration and parasite spore loads increases with the age of infection. Driving these patterns appears to be variation in how well the parasite maintains control of host reproduction late in the infection process. We discuss the evolutionary consequences of this finding with regard to natural selection acting on different ages of infection and the mechanism underlying the maintenance of castration efficiency. Our results highlight how elucidating within-host dynamics can shed light on the selective forces that shape infection strategies and the evolution of virulence.     

Normal giants? Temporal and latitudinal shifts of Palaeozoic marine invertebrate gigantism and global change

During and after the Cambrian explosion, very large marine invertebrate species have evolved in several groups. Gigantism in Carboniferous land invertebrates has been explained by a peak in atmospheric oxygen concentrations, but Palaeozoic marine invertebrate gigantism has not been studied empirically and explained comprehensively. By quantifying the spatiotemporal distribution of the largest representatives of some of the major marine invertebrate clades (orthoconic cephalopods, ammonoids, trilobites, marine eurypterids), we assessed possible links between environmental parameters (atmospheric or oceanic oxygen concentrations, ocean water temperature or sea level) and maximum body size, but we could not find a straightforward relationship between both. Nevertheless, marine invertebrate gigantism within these groups was temporally concentrated within intervals of high taxonomic diversity (Ordovician, Devonian) and spatially correlated with latitudes of high occurrence frequency. Regardless of whether temporal and spatial variation in sampled diversity and occurrence frequency reflect true biological patterns or sampling controls, we find no evidence that the occurrences of giants in these groups were controlled by optimal conditions other than those that controlled the group as a whole; if these conditions shift latitudinally, occurrences of giants will shift as well. It is tempting to attribute these shifts to contemporary changes in temperature, oxygen concentrations in the atmosphere and the oceans as well as global palaeogeography over time, but further collection‐based studies are necessary on finer stratigraphic and phylogenetic resolution to corroborate such hypotheses and rule out sampling or collection biases.     

Fecundity selection does not vary along a large geographical cline of trait means in a passerine bird

Local environmental and ecological conditions are commonly expected to result in local adaptation, although there are few examples of variation in phenotypic selection across continent‐wide spatial scales. We collected standardized data on selection with respect to the highly variable plumage coloration of pied flycatcher (Ficedula hypoleuca Pall.) males from 17 populations across the species' breeding range. The observed selection on multiple male coloration traits via the annual number of fledged young was generally relatively weak. The main aim of the present study, however, was to examine whether the current directional selection estimates are associated with distance to the sympatric area with the collared flycatcher (Ficedula albicollis Temminck), a sister species with which the pied flycatcher is showing character displacement. This pattern was expected because plumage traits in male pied flycatchers are changing with the distance to these areas of sympatry. However, we did not find such a pattern in current selection on coloration. There were no associations between current directional selection on ornamentation and latitude or longitude either. Interestingly, current selection on coloration traits was not associated with the observed mean plumage traits of the populations. Thus, there do not appear to be geographical gradients in current directional fecundity selection on male plumage ornamentation. The results of the present study do not support the idea that constant patterns in directional fecundity selection would play a major role in the maintenance of coloration among populations in this species. By contrast, the tendency for relatively weak mosaic‐like variation in selection among populations could reflect just a snapshot of temporally variable, potentially environment‐dependent, selection, as suggested by other studies in this system. Such fine‐grained variable selection coupled with gene flow could maintain extensive phenotypic variation across populations. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 808–827.