Zinc-binding properties of Junín virus nucleocapsid protein

The arenavirus nucleocapsid protein (N) is a highly basic 63 kDa protein with a dual function during the virus life-cycle. First, it is involved in essential steps of genome replication, promoting the synthesis of the full-length antigenomic copy of S RNA, and second it associates with the genomic RNA to form the nucleocapsid. We have expressed the N protein of Junín virus in E. coli and shown that it binds zinc in vitro. This property is in agreement with the presence in the carboxy-terminal region of the N protein of the CX2HX23CX4C sequence, which resembles a classical zinc-finger motif. The specificity for zinc binding was demonstrated by competition with other divalent metal ions. The ability of the predicted motif to bind zinc was established by analysis of a series of N mutants, including truncated variants and amino acid substitutions. In addition, alternative zinc-binding sites were found.Instituto de Biotecnologia y Biologia Molecula

Influence of distance from the host on parasitisation by Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)

The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited at 2.5 and 3 mm due to the ovipositor length of the parasitoid females (2.7 mm). Hosts were easily parasitised at distances between 0 and 1.5 mm. The thin fruit pulp (up to 3.5 mm) of field collected olives allowed the parasitisation to occur also in mature fruits. At the best combination distance/time (0 mm, 30 min), tests performed with different larvae/parasitoid female ratio showed an increasing emergence of P. concolor (from 20% to 57%) with larvae/parasitoid ratio increasing from 0.11 to 0.74. The results of the present study might optimise the mass rearing of P. concolor, through a proper setting of its parameters, such as the host/parasitoid ratio, exposure distances, and interaction time

A morphological, biological and molecular approach reveals four cryptic species of Trissolcus Ashmead (Hymenoptera, Scelionidae), egg parasitoids of Pentatomidae (Hemiptera)

Accurate identification of parasitoids is crucial for biological control of the invasive brown marmorated stink bug, Halyomrpha halys (Stål). A recent work by Talamas et al. (2017) revised the Palearctic fauna of Trissolcus Ashmead, egg-parasitoids of stink bugs, and treated numerous species as junior synonyms of T. semistriatus (Nees von Esenbeck). In the present paper, we provide a detailed taxonomic history and treatment of T. semistriatus and the species treated as its synonyms by Talamas et al. (2017) based on examination of primary types, molecular analyses and mating experiments. Trissolcus semistriatus, T. belenus (Walker), T. colemani (Crawford), and T. manteroi (Kieffer) are here recognized as valid and a key to species is provided. The identification tools provided here will facilitate the use of Trissolcus wasps as biological control agents and as the subject of ecological studies

The invasive tomato pest Tuta absoluta can transmit the emergent tomato brown rugose fruit virus.

The tomato brown rugose fruit virus (ToBRFV) currently represents one of the most significant threats to tomato crop worldwide. Its transmission occurs mainly through contact between plants and infected surfaces, and only one case of mechanical transmission by arthropods has been reported. Here, we aim to assess the role of an invasive tomato pest, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in ToBRFV transmission. Laboratory tests demonstrated the presence of the ToBRFV in adult moths obtained from larvae developed on ToBRFV-infected plants. Infected adults of T. absoluta were able to infect healthy tomato plants. In order to evaluate whether the occurrence of ToBRFV on T. absoluta adults was internal or external to the pupae, as results of larvae feeding on infected plants, pupae obtained from larvae fed on infected plants were externally disinfected and then analyzed for the presence of ToBRFV by RT-qPCR. Adults obtained from disinfected and not-disinfected pupae were also analyzed. Both adults and pupae were positive for the virus, suggesting its presence in the inner surface of the pupal exuvia. Electron microscopy, western blot analyses and hemolymph bioassay showed the absence of ToBRFV virions and viral coat protein in the hemolymph collected from disinfected pupae, demonstrating that the ToBRFV is not circulative in the progeny of T. absoluta adults obtained from larvae fed in infected plants, but probably adults got contaminated during their emergence, due to virus presence in the inner surface of pupal exuvia. This study demonstrates for the first time that T. absoluta can carry an infectious primary inoculum of ToBRFV, highlighting a potential epidemiological role of T. absoluta in spreading ToBRFV in the field

incidence of hepatitis c virus infection in patients with chronic kidney disease on conservative therapy

Summary Hepatitis C virus (HCV) infection is a never-ending public health problem. Many studies have investigated the incidence of HCV infection among dialysis patients, but there have only been a few epidemiological studies in renal conservative therapy. We studied 320 subjects with pre-dialysis chronic kidney disease living in Sicily, Italy. The incidence of HCV infection was 6.25%. In Europe, incidence ranges from 0.2% to 3.5%. It appears that the incidence of HCV infection is higher in the studied patient population than in the population as a whole