Diapause as escape strategy to exposure to toxicants: response of Brachionus calyciforus to arsenic

Invertebrate organisms commonly respond to environmental fluctuation by entering diapause. Production of diapause in monogonont rotifers involves a previous switch from asexual to partial sexual reproduction. Although zooplankton have been used in ecotoxicological assays, often their true vulnerability to toxicants is underestimated by not incorporating the sexual phase. We experimentally analyzed traits involved in sexual reproduction and diapause in the cyclically parthenogenetic freshwater rotifer, Brachionus calyciflorus, exposed to arsenic, a metalloid naturally found in high concentrations in desert zones, focusing on the effectiveness of diapause as an escape response in the face of an adverse condition. Addition of sublethal concentrations of arsenic modified the pattern of diapause observed in the rotifer: investment in diapause with arsenic addition peaked earlier and higher than in non-toxicant conditions, which suggests that sexual investment could be enhanced in highly stressed environmental conditions by increased responsiveness to stimulation. Nevertheless, eggs produced in large amount with arsenic, were mostly low quality, and healthy-looking eggs had lower hatching success, therefore it is unclear whether this pattern is optimum in an environment with arsenic, or if rather arsenic presence in water bodies disturbs the optimal allocation of offspring entering diapause. We observed high accumulation of arsenic in organisms exposed to constant concentration after several generations, which suggests that arsenic may be accumulated transgenerationally. The sexual phase in rotifers may be more sensitive to environmental conditions than the asexual one, therefore diapause attributes should be considered in ecotoxicological assessment because of its ecological and evolutionary implications on lakes biodiversity

Malaria vector species in Colombia: a review

Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai) is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species' geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species

Three years' experience of sexually transmitted diseases in Seville, Spain.

At present there are no reliable statistics on the relative prevalences of sexually transmitted diseases (STDs) in Spain. In a report of the first three years' experience in an STD diagnostic centre between 1977 and 1979 a total of 879 patients (534 men adn 345 women) were seen. They mainly consisted of university students and the mean age was 22 years in 1977 and 23 years in the following two years. All the patients were examined for syphilis and all women for gonorrhoea and trichomoniasis. Investigations for Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Candida albicans, and Herpesvirus hominis infections were carried out according to the presenting symptoms. Non-specific genital infections occurred most commonly (25.7%); chlamydia were isolated from 30% of the patients with non-gonococcal urethritis (NGU). The second commonest infection was candidosis (13.5%). Gonorrhoea, which was found in 10.6% of the patients, was diagnosed more frequently in men (13.5%) than in women (6%). No strains of beta-lactamase-producing Neisseria gonorrhoeae were detected and all were sensitive to penicillin. Syphilis was diagnosed in 4.4% of patients (2% women and 5% men). Condylomata acuminata were diagnosed in 2.8% of patients and more frequently in men (4%). Herpes genitalis and venereophobia were uncommon (1.9% and 1.2% respectively) and were diagnosed only in men

Genome sequencing and secondary metabolism of the postharvest pathogen Penicillium griseofulvum

BACKGROUND: Penicillium griseofulvum is associated in stored apples with blue mould, the most important postharvest disease of pome fruit. This pathogen can simultaneously produce both detrimental and beneficial secondary metabolites (SM). In order to gain insight into SM synthesis in P. griseofulvum in vitro and during disease development on apple, we sequenced the genome of P. griseofulvum strain PG3 and analysed important SM clusters. RESULTS: PG3 genome sequence (29.3 Mb) shows that P. griseofulvum branched off after the divergence of P. oxalicum but before the divergence of P. chrysogenum. Genome-wide analysis of P. griseofulvum revealed putative gene clusters for patulin, griseofulvin and roquefortine C biosynthesis. Furthermore, we quantified the SM production in vitro and on apples during the course of infection. The expression kinetics of key genes of SM produced in infected apple were examined. We found additional SM clusters, including those potentially responsible for the synthesis of penicillin, yanuthone D, cyclopiazonic acid and we predicted a cluster putatively responsible for the synthesis of chanoclavine I. CONCLUSIONS: These findings provide relevant information to understand the molecular basis of SM biosynthesis in P. griseofulvum, to allow further research directed to the overexpression or blocking the synthesis of specific SM.Work at the University of Torino was partially supported by the LIFE financial instrument of the European Union (Contract LIFE13 ENV/HR/000580). TG group research was partially funded by a grant from the Spanish Ministry of Economy and Competitiveness (BIO2012-37161), a grant from the Qatar National Research Fund (NPRP5-298-3-086), and a grant from the European Research Council (Grant Agreement ERC-2012-StG-310325). Work at LGC lab was partially supported by a grant from the Spanish Ministry of Economy and Innovation (AGL2011-30519-C03-01) and by the Generalitat Valenciana, Spain (PROMETEOII/2014/027). ARB is grateful to CSIC and the European Social Fund for her postdoctoral contract JAE-Do

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown−no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen−virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations

Characterization of ecologically diverse viruses infecting co-occurring strains of cosmopolitan hyperhalophilic bacteroidetes

Hypersaline environments close to saturation harbor the highest density of virus-like particles reported for aquatic systems as well as low microbial diversity. Thus, they offer unique settings for studying virus-host interactions in nature. However, no viruses have been isolated so far infecting the two most abundant inhabitants of these systems (that is, the euryarchaeon Haloquadratum walsbyi and the bacteroidetes Salinibacter ruber). Here, using three different co-occurring strains, we have isolated eight viruses infecting the ubiquitous S. ruber that constitute three new different genera (named as 'Holosalinivirus', 'Kryptosalinivirus' and 'Kairosalinivirus') according to their genomic traits, different host range, virus-host interaction capabilities and abundances in natural systems worldwide. Furthermore, to get a more complete and comprehensive view of S. ruber virus assemblages in nature, a microcosm experiment was set with a mixture of S. ruber strains challenged with a brine virus concentrate, and changes of viral populations were monitored by viral metagenomics. Only viruses closely related to kairosalinivirus (strictly lytic and wide host range) were enriched, despite their low initial abundance in the natural sample. Metagenomic analyses of the mesocosms allowed the complete recovery of kairosalinivirus genomes using an ad hoc assembly strategy as common viral metagenomic assembly tools failed despite their abundance, which underlines the limitations of current approaches. The increase of this type of viruses was accompanied by an increase in the diversity of the group, as shown by contig recruitment. These results are consistent with a scenario in which host range, not only virus and host abundances, is a key factor in determining virus fate in nature.This research was supported by the Spanish Ministry of Economy projects CLG2015_66686-C3-1 (to JA) and CLG2015_66686-C3-3 (to RRM), which were also supported with European Regional Development Fund (FEDER) funds