Environmental resistance development to influenza antivirals: a case exemplifying the need for a multidisciplinary One Health approach including physicians

Medicinal Chemistry Gone Wild

Earth is currently experiencing a mass extinction event. The flora and fauna of our planet are experiencing mass die-offs from a multitude of factors, with wildlife disease emerging as one parameter where medicinal chemists are equipped to intervene. While contemporary medicinal chemistry focuses on human health, many traditional pharmaceutical companies have historic roots in human health, animal health, and plant health. This trifecta of health sciences perfectly maps to the current field of One Health, which recognizes that optimal health outcomes can only be achieved through the health of humans, plants, animals, and their shared environments. This Perspective imagines a world where state-of-the-art medicinal chemistry tactics are used to prevent the extinction of endangered species and points to preliminary work in the emerging area of conservation medicine.

Neuraminidase characterisation reveals very low levels of antiviral resistance and the presence of mutations associated with reduced antibody effectiveness in the Irish influenza 2018/2019 season

•

Very low antiviral resistance in Irish 2018/2019 influenza season.

•

Supports current antiviral use.

•

Continued molecular neuraminidase surveillance essential for resistance emergence.

•

Surveillance also useful for monitoring vaccine effectiveness.

•

Mutations associated with reduced antibody effectiveness detected.

Neuraminidase inhibitor (NAI) resistance levels globally are currently low. However, as antivirals are increasingly being used, and even in the absence of selective pressure, resistance may increase or emerge. The neuraminidase (NA) genes from influenza viruses from the Irish 2018/2019 season were sequenced: 1/144 (0.7 %) A(H1N1)pdm09 sequences harboured a substitution associated with highly-reduced susceptibility to NAIs. The very low NAI resistance we describe supports current Irish NAI use recommendations. However, continued monitoring is essential. NA characterisation also identified substitutions associated with reduced antibody effectiveness, thereby highlighting the potential of NA sequence surveillance as an additional tool for investigating influenza vaccine effectiveness (VE).

INFLUENZA REQUIERE UN MANEJO BAJO LA PERSPECTIVA DE “ONE HEALTH” EN COLOMBIA

La influenza es una infección viral de importancia y distribución mundial, cuyo agente causal es el Alfainfluenzavirus o influenza virus tipo A (IAV). El cual se caracteriza por poseer un genoma de tipo ssRNA segmentado, lo cual le confiere una alta variabilidad y capacidad recombinante. Esto, sumado al amplio rango de huéspedes susceptibles y la posibilidad de transmisión entre especies, se constituye en un reto tanto para la salud humana como animal. El IAV es capaz de infectar una amplia variedad de huéspedes, incluyendo múltiples especies de aves y mamíferos, tanto domésticos como salvajes y al humano, así como a reptiles y anfibios, entre otros. Dentro de los Alphainfluenzavirus se reconocen 16 subtipos de Hemaglutinina (HA) y 9 de Neuraminidasa (NA), siendo su principal reservorio las aves silvestres acuáticas. Adicionalmente se han reconocido dos nuevos subtipos en murciélagos (H17-18 y N10-11), los cuales se han denominado Influenza-like virus. Teniendo en cuenta lo anterior y conocedores de la riqueza en biodiversidad que posee Colombia, país en el que está demostrada la circulación del virus en cerdos y en humanos y hay resultados preliminares de la presencia de Orthomyxovirus en murciélagos, es imperativo estudiar y conocer los IAV circulantes en el medio, establecer factores de riesgo y analizar el efecto que ha tenido y seguirán teniendo condiciones asociadas al cambio climático, los factores sociodemográficos y el papel de diferentes especies en la ecología de este agente viral. Todo lo anterior bajo el contexto de “una salud” en la infección por IAV.

Impact of long-term parental exposure to Tamiflu metabolites on the development medaka offspring (Oryzias latipes)

Despite the widespread use of the antiviral drug, Tamiflu®, little is known about the long-term toxic effects of drug or its metabolites in an aquatic ecosystem. This study integrated epidemiological and ecotoxicological methods to determine environmentally relevant concentrations of Tamiflu. A model based on the species medaka (Oryzias latipes) was then used to determine the health status and reproductivity of adults exposed to the drug as well as the embryonic development of offspring. The proposed ecotoxicological model was also used to quantitatively and qualitatively evaluate the toxicodynamic parameters related to egg production, hatchability, and development. Our results revealed that at an environmentally relevant exposure, Tamiflu and its metabolites had no adverse effects on growth, survival, or fecundity of adult medaka. Nonetheless, we observed a reduction in hatchability under exposure to 300 μg L^-1 and a reduction in body length under exposure exceeding 90 μg L^-1. Under exposure to 300 μg L^-1, the estimated spawning time to reach 50% of the maximum percentage of cumulative egg production (ET50) far exceeded that of the control group (without exposure to Tamiflu). We also observed a ∼ 3-fold decrease in maximum egg hatching (E_max). Based on an integrated epidemiological and ecotoxicological model, predictions of environmental concentrations of Tamiflu and its metabolites revealed that the influenza subtypes associated with increases in environmental concentrations: A(H3N2) > A(H1N1) > type B (in order of their effects). We also determined that A(H3N2) posed a potential risk to hatchability and development. Note however, the environmental concentrations of Tamiflu and its metabolites in most countries are lower than the effect concentrations derived in this study, indicating no hazards for aquatic environments. We recommend the use of hatchability and embryonic development as indicators in assessing the effects of long-term parental exposure to Tamiflu metabolites.

Evolutionary, genetic, structural characterization and its functional implications for the influenza A (H1N1) infection outbreak in India from 2009 to 2017

Influenza A (H1N1) continues to be a major public health threat due to possible emergence of a more virulent H1N1 strain resulting from dynamic changes in virus adaptability consequent to functional mutations and antigenic drift in the hemagglutinin (HA) and neuraminidase (NA) surface proteins. In this study, we describe the genetic and evolutionary characteristics of H1N1 strains that circulated in India over a period of nine years from 2009 to 2017 in relation to global strains. The finding is important from a global perspective since previous phylogenetic studies have suggested that the tropics contributed substantially to the global circulation of influenza viruses. Bayesian phylogenic analysis of HA sequences along with global strains indicated that there is a temporal pattern of H1N1 evolution and clustering of Indian isolates with globally circulating strains. Interestingly, we observed four new amino acid substitutions (S179N, I233T, S181T and I312V) in the HA sequence of H1N1 strains isolated during 2017 and two (S181T and I312V) were found to be unique in Indian isolates. Structurally these two unique mutations could lead to altered glycan specificity of the HA gene. Similarly, sequence and structural analysis of NA domain revealed that the presence of K432E mutation in H1N1 strains isolated after 2015 from India and in global strains found to induce a major loop shift in the vicinity of the catalytic site. The findings presented here offer an insight as to how these acquired mutations could be associated to an improved adaptability of the virus for efficient human transmissibility.

Inventory of molecular markers affecting biological characteristics of avian influenza A viruses

Avian influenza viruses (AIVs) circulate globally, spilling over into domestic poultry and causing zoonotic infections in humans. Fortunately, AIVs are not yet capable of causing sustained human-to-human infection; however, AIVs are still a high risk as future pandemic strains, especially if they acquire further mutations that facilitate human infection and/or increase pathogenesis. Molecular characterization of sequencing data for known genetic markers associated with AIV adaptation, transmission, and antiviral resistance allows for fast, efficient assessment of AIV risk. Here we summarize and update the current knowledge on experimentally verified molecular markers involved in AIV pathogenicity, receptor binding, replicative capacity, and transmission in both poultry and mammals with a broad focus to include data available on other AIV subtypes outside of A/H5N1 and A/H7N9.

The enzyme toilet rim block 'pCure' does not efficiently remove drug residues in a hospital setting - exemplifying the importance of on-site implementation testing

Introduction: Negative environmental effects of active pharmaceutical ingredients (APIs) are increasingly recognized, especially concerning antibiotics, and hospitals are important point sources. “pCure” is a toilet rim block containing API-degrading enzymes; the producing company claims positive in vitro results but no implementation studies have been performed. Materials and methods: In a university hospital setting, 16 weeks were randomized to installation or no installation of pCure in all 261 toilets connected to the same cesspit where sewage water was sampled daily. Ninety-six samples were analyzed for 102 APIs using liquid chromatography/tandem mass spectrometry. Results and Discussion: Fifty-one APIs were detected with a large variation in levels but no significant differences in the initial statistical analysis. More statistical testing of API level ratios (pCure installed/not installed) yielded some cases of significant decrease. Differences were small and not consistent when comparing means and medians. We cannot exclude a small pCure effect but clearly pCure has no effect of biological importance. Conclusion: pCure is not useful to reduce drug residue discharge in a hospital setting. In a bigger perspective, our study exemplifies that products claiming to reduce an environmental problem need to be tested in on-site implementation studies by independent researchers before reaching the market.