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For decades, we have observed a major biodiversity crisis impacting all taxa. Avian species have been particularly well monitored over the long term, documenting their declines. In particular, farmland birds are decreasing worldwide, but the contribution of pesticides to their decline remains controversial. Most studies addressing the effects of agrochemicals are limited to their assessment under controlled laboratory conditions, the determination of lethal dose 50 (LD50) values and testing in a few species, most belonging to Galliformes. They often ignore the high interspecies variability in sensitivity, delayed sublethal effects on the physiology, behaviour and life-history traits of individuals and their consequences at the population and community levels. Most importantly, they have entirely neglected to test for the multiple exposure pathways to which individuals are subjected in the field (cocktail effects). The present review aims to provide a comprehensive overview for ecologists, evolutionary ecologists and conservationists. We aimed to compile the literature on the effects of pesticides on bird physiology, behaviour and life-history traits, collecting evidence from model and wild species and from field and lab experiments to highlight the gaps that remain to be filled. We show how subtle nonlethal exposure might be pernicious, with major consequences for bird populations and communities. We finally propose several prospective guidelines for future studies that may be considered to meet urgent needs. [ABSTRACT FROM AUTHOR]

Background: The house mouse (Mus musculus) is a globally distributed rodent pest species against which anticoagulant rodenticides are widely used for the protection of human and animal health and the conservation of threatened wildlife. Anticoagulant‐resistant house mice have been known for more than half a century. A house mouse strain was developed in the laboratory that was homozygous resistant for the single nucleotide polymorphism (SNP) Tyrosine139Cysteine (Y139C) and, subsequently, heterozygous resistant animals were produced from this strain by crossing with the homozygous susceptible strain. Results: Using blood clotting response tests, resistance factors at the ED50 level in the homozygous resistant strain for the first‐generation anticoagulants warfarin, chlorophacinone, diphacinone and coumatetralyl were in the range 31.5 to 628.0 for males (M) and 21.6 to 628.0 for females (F), thus indicating that Y139C house mice are substantially resistant to all these substances. Resistance factors at the ED50 level for the homozygous strain generated against the second‐generation compounds were: brodifacoum (M, 1.7; F, 1.9), bromadiolone (M, 16.6; F, 21.0), difenacoum (M, 1.2; F, 2.7), difethialone (M, 1.5; F, 1.5), and flocoumafen (M, 0.9; F, 1.2). Equivalent values for the heterozygous strain were: brodifacoum (M, 1.6; F, 1.4), bromadiolone (M, 5.6; F, 6.5), difenacoum (M, 1.0; F, 1.3), difethialone (M, 1.1; F, 1.1), flocoumafen (M, 0.9; F, 1.1). Conclusion: Y139C SNP homozygous resistant mice are more resistant to anticoagulants than heterozygous resistant animals. All first‐generation anticoagulants are highly resisted and, among the second‐generation compounds, Y139C mice are resistant to bromadiolone and sometimes to difenacoum. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Chemical substances are used worldwide as rodenticides, insecticides and herbicides, and also to protect animals against ectoparasites. Poisoning from chemical substances can occur in dogs and cats from both non-accidental and accidental causes. Non-accidental causes include the intentional abuse of chemical substances. This is regarded as animal cruelty and is illegal in many countries. By contrast, accidental causes result from animals ingesting poisonous substances unintentionally such as baits containing rodenticides or eating dead or alive poisoned rodents. Knowledgeable use of poisonous chemicals is vital for the safety of pets. Clinical signs of poisoning in dogs and cats depend on the type of chemical substances, species, lethal dose (LD50) and duration after exposure. This review summarises the common chemical substances that can endanger dogs and cats including rodenticides, insecticides, molluscicides, herbicides, paracetamol and antifreeze chemicals (ethylene glycol). [ABSTRACT FROM AUTHOR]

Background: Invasive non-typhoidal Salmonella (iNTS–mainly serotypes Enteritidis and Typhimurium) are major causes of bloodstream infections in children in sub-Saharan Africa, but their reservoir remains unknown. We assessed iNTS carriage in rats in an urban setting endemic for iNTS carriage and compared genetic profiles of iNTS from rats with those isolated from humans. Methodology/Principal findings: From April 2016 to December 2018, rats were trapped in five marketplaces and a slaughterhouse in Kisangani, Democratic Republic of the Congo. After euthanasia, blood, liver, spleen, and rectal content were cultured for Salmonella. Genetic relatedness between iNTS from rats and humans—obtained from blood cultures at Kisangani University Hospital—was assessed with multilocus variable-number tandem repeat (VNTR) analysis (MLVA), multilocus sequence typing (MLST) and core-genome MLST (cgMLST). 1650 live-capture traps yielded 566 (34.3%) rats (95.6% Rattus norvegicus, 4.4% Rattus rattus); 46 (8.1%) of them carried Salmonella, of which 13 had more than one serotype. The most common serotypes were II.42:r:- (n = 18 rats), Kapemba (n = 12), Weltevreden and Typhimurium (n = 10, each), and Dublin (n = 8). Salmonella Typhimurium belonged to MLST ST19 (n = 7 rats) and the invasive ST313 (n = 3, isolated from deep organs but not from rectal content). Sixteen human S. Typhimurium isolates (all ST313) were available for comparison: MLVA and cgMLST revealed two distinct rat-human clusters involving both six human isolates, respectively, i.e. in total 12/16 human ST313 isolates. All ST313 Typhimurium isolates from rats and humans clustered with the ST313 Lineage 2 isolates and most were multidrug resistant; the remaining isolates from rats including S. Typhimurium ST19 were pan-susceptible.s1 Conclusion: The present study provides evidence of urban rats as potential reservoirs of S. Typhimurium ST313 in an iNTS endemic area in sub-Saharan Africa. Author summary: Dadi (°1974, DR Congo) is a Medical Doctor (Kisangani University 2005) with a master in pediatrics (Kisangani University 2015) with special interest in infectious diseases and tropical medicine. He has 11 years of field research experience. He was team member of scientific expedition "Boyekoli Ebale Congo" in 2010 as medical support of the researchers. He conducted work field in a multidisciplinary framework with biologists from faculty of sciences (university of Kisangani) exploring zoonotic diseases in several places in the Congo. Currently, he is doing his PhD research at KU Leuven and Institute of Tropical Medicine Antwerp (ITM), Belgium. Passionate about transmissible diseases, Dadi is exploring the potential reservoirs of Non-typhoidal Salmonella in Kisangani, DR Congo. [ABSTRACT FROM AUTHOR]

Genetic resistance to anticoagulants caused by mutations in the Vkorc1 gene of the most invasive rodent species—Norway rats and house mice, has not been studied in Russia. We analyzed the variability of the Vkorc1 gene in house mice and Norway rats in various settlements of Russia, and identified mutations responsible for resistance to rodenticides. Two exons of the Vkorc1 gene were analyzed in 71 Norway rats from four cities (Moscow, Tyumen, Chita, Rostov-on-Don) and 108 house mice from cities and small settlements (Moscow region, Tormosin, Nizhny Tsasuchei). Three Norway rats (15.8% of the studied individuals) in Moscow have a heterozygous state the Tyr139Ser mutation, which is responsible for resistance. House mice were not found to have mutations in the Vkorc1 gene responsible for resistance to anticoagulants of the first and second generation in the Leu128Ser and Tyr139Cys positions located in the third exon. However, in cities in the first exon, we identified two heterozygous mutations have not be described previously in the scientific literature: Lys58Arg and Ser31Trp. In Russia, the genetic resistance to rodenticides in settlements in the populations of house mice and Norway rats is significantly lower than in Western Europe. [ABSTRACT FROM AUTHOR]

House mouse (Mus musculus) is a cosmopolitan pest in agricultural facilities, commodity stores and rural and urban environments. It is regularly controlled by anticoagulant-based baits. Since the number of registered active ingredients is limited, the producers are trying to develop new formulations with increased tamper-resistance, attractiveness and palatability. Reliable and economical methods for laboratory screening/testing are needed. Therefore, this work compared simple no-choice with more economically demanding choice feeding tests for laboratory evaluation of efficacy of rodenticide anticoagulant-based preparations in wild populations of house mouse. We analyzed mice survival and bait intake of the various rodenticide commercial preparations differing in a toxic active substance (warfarin, bromadiolone, brodifacoum, difethialone) and nontoxic food lure components. In most cases, we found insignificant differences in survival of house mice treated with eight test baits within the no-choice and choice feeding tests. We rejected the tested hypothesis that there would be significant differences in all tested preparations for two different testing approaches. [ABSTRACT FROM AUTHOR]

Anticoagulant rodenticides (ARs) continue to be used across the United States as a method for controlling pest rodent species. As a consequence, wild birds of prey are exposed to these toxicants by eating poisoned prey items. ARs prevent the hepatic recycling of vitamin K and thereby impede the post-translational processing of coagulation factors II, VII, IX, and X that are required for procoagulant complex assembly. Through this mechanism of action, ARs cause hemorrhage and death in their target species. Various studies have documented the persistence of these contaminants in birds of prey but few have attempted to use affordable and accessible diagnostic tests to diagnose coagulopathy in free-ranging birds of prey. In our study free-ranging red-tailed hawks were found to be exposed to difethialone and brodifacoum. Eleven of sixteen (68%) livers tested for AR exposure had detectable residues. Difethialone was found in 1/16 (6%), and brodifacoum was detected in 10/16 (62%) liver samples that were tested for rodenticide residues. Difethialone was found at a concentration of 0.18 ug/g wet weight and brodifacoum concentrations ranged from 0.003–0.234 ug/g wet weight. Two out of 34 (6%) RTHA assessed for blood rodenticide had brodifacoum in serum with measured concentrations of 0.003 and 0.006 ug/g. The range of clotting times in the prothrombin time (PT) and Russell's viper venom time assays for control RTHA were 16.7 to 39.7 s and 11.5 to 91.8 s, respectively. One study bird was diagnosed with clinical AR intoxication with a brodifacoum levels in blood of 0.006 and 0.234 ug/g wet weight in blood and liver respectively, a packed cell volume (PCV) of 19%, and PT and RVVT times of >180 s. No correlation was found between PT and RVVT in the control or free-range RTHA, and there was no relationship found between the presence of liver anticoagulant residues and clotting times in the PT and RVVT. [ABSTRACT FROM AUTHOR]

Commensal rodents are those species that have adapted to feeding, breeding and travelling around the world with humans, as opposed to their relatives who remain fully wild. Three species of commensal rodents each invaded New Zealand many times before about 1830. All carry in their genomes evidence of their origins, which not only confirm known precolonial trade routes in the south-western Pacific during the late eighteenth and early nineteenth centuries, but also extend them into conclusions invisible to archival records. Pacific rats (Rattus exulans) arrived with Polynesian colonists from their home islands in eastern Polynesia in about 1280 CE. They have become a mine of genetic information for deducing the history of human colonisation of the Pacific islands. House mice (Mus musculus) and Norway rats (Rattus norvegicus) both originated in Asia, and spread from there along with people to western Europe by the mid-1700s. Both were carried by the early European and American ships among cargo, livestock and immigrants to Australia, and thence to New Zealand. They provide evidence of a hitherto unknown short but important clandestine connection with China over about 20 years after 1800. A fourth species of commensal rodent to reach New Zealand, the ship rat (Rattus rattus), arrived only in about 1830-50. [ABSTRACT FROM AUTHOR]

Warfarin is commonly used worldwide as a rodenticide. It inhibits coagulation of blood by inhibiting vitamin K 2,3-epoxide reductase (VKOR) activity. An inadequate supply of vitamin K blocks the production of prothrombin and causes hemorrhage. It has been reported that repeated or long-term treatments with this drug cause resistance in wild rodents. However, the mechanism of warfarin resistance in rodents is still not known precisely. Recent studies reported and identified the function of the molecule, vitamin K epoxide reductase complex subunit 1 (VKORC1), which is the main unit of VKOR. An amino acid substitution in VKORC1 is one of the supposed mechanisms of warfarin resistance. An accelerated detoxification system involving cytochrome P450 (CYP) could also cause the rodenticide resistance Administration of SKF 525A, a potent inhibitor for P450, increased the mortality due to reduction of warfarin metabolism in warfarin-resistant rats. Meanwhile, the appearance of warfarin resistant rodents has led to the development of the more effective and toxic rodenticide superwarfarin, which is widely used in Europe and the USA. However, animals resistant to this second generation rodenticide have already been reported in Europe. In this review, we focus on the mechanism and the pleiotropic effects of pesticide resistance in wild rodents. [ABSTRACT FROM AUTHOR]

Vector control remains an important strategy in preventing rodent-borne diseases. Studies quantifying the impact of anticoagulant bait use on rodent populations are scarce in tropical settings. This study examined the impact of anticoagulant bait use on three measures of rodent activity in Singapore to inform rodent-borne disease control strategies. Using a controlled interrupted time-series analytical design with negative binomial and linear regression models, the average rodent activity levels were compared in the pre- and post-intervention periods. There was a 62.7% (Incidence Rate Ratio (IRR): 0.373, 95% CI: [0.224, 0.620]) reduction in the number of rodents caught, a 25.8-unit (coefficient = -25.829, 95% CI: [-29.855, -21.804]) reduction in the number of 30 g/unit baits consumed and a 61.9% (IRR: 0.381, 95% CI: [0.218, 0.665]) reduction in the number of marred bait stations relative to the pre-intervention period. There was a rise in all three outcome measures within four months after the post-intervention period. This study provided strong evidence that anticoagulant baits substantially reduces rodent activity. The population resurgence after the post-intervention period reinforces the importance of timing the resumption of control measures aimed at reducing rodent-borne disease transmission. [ABSTRACT FROM AUTHOR]

The present genetic diversity of commensal rodent populations is often used to inform the invasion histories of these species, and as a proxy for historical events relating to the movement of people and goods. These studies assume that modern genetic diversity generally reflects early colonising events. We investigate this idea by sequencing the mitochondrial DNA of rodent bones found in a 19th-century archaeological site in The Rocks area of Sydney, Australia, the location of the first historical European port (Port Jackson) in Australasia. We also interpret the history of rodent invasions in New Zealand based on this evidence, as Sydney was the primary port from which European boats sailed to New Zealand. We identified 19th-century bones from two species, Norway rats (Rattus norvegicus) and house mice (Mus musculus domesticus). We found six historical genetic haplotypes in the 39 Norway rats, showing either multiple early introductions or a diverse initial founding population. One of them was identical with Norhap01 common in the North Island of New Zealand, but none was like the haplotype Norhap02 found throughout the South Island. We found three haplotypes in seven house mice, all belonging to the dominant subspecies established in Australia, M.m. domesticus. We had few modern Norway rat and house mouse DNA sequences from Sydney, but those we had did tentatively support the hypotheses that (1) modern samples can represent at least a preliminary estimate of historical diversities and origins, and (2) Asian haplotypes of both Norway rats and of house mice reached the South Island of New Zealand early in colonial times direct from China rather than through Port Jackson. [ABSTRACT FROM AUTHOR]

Invasive mice (Mus spp.) can negatively impact island species and ecosystems. Because fewer island rodent eradications have been attempted for mice compared to rats (Rattus spp.), less is known about efficacy and palatability of rodenticide baits for mouse eradications. We performed a series of bait acceptance and efficacy cage trials using a standard formulation of brodifacoum-based rodenticide on wild-caught mice from Sand Island, Midway Atoll, to help inform a proposed eradication there. Mice were offered ad libitum brodifacoum pellets along with various alternative food sources, and a "no choice" treatment group received only bait pellets. Mortality in the no choice trial was 100%; however, when offered alternative foods, mice preferred the alternative diets to the bait, leading to low mortality (40%). Because there was concern that the bittering agent Bitrex® in the formulation may have reduced palatability, we conducted a subsequent trial comparing brodifacoum bait with and without Bitrex. Mortality in the with-Bitrex treatment group was slightly higher, indicating that the bittering agent was not likely responsible for low efficacy. Laboratory trials cannot account for the numerous environmental and behavioral factors that influence bait acceptance nor replicate the true availability of alternative food sources in the environment, so low efficacy results from these trials should be interpreted cautiously and not necessarily as a measure of the likelihood of success or failure of a proposed eradication. [ABSTRACT FROM AUTHOR]

BACKGROUND: Norway rats (Rattus norvegicus) need to be controlled to prevent transmission of pathogens and damages to stored products and material, leading to considerable economic risks and losses. Given increasing resistance in Norway rats, the most persistent, bio‐accumulative and toxic anticoagulant rodenticides are widely used for management, which presents hazards to the environment especially for non‐target species. We investigated how sanitary measures improved management of Norway rats on 12 paired livestock farms in a region of Germany with a high population of resistant rats for reducing application of rodenticides. We recorded food intake, and tracked activity and resistance frequency during the pre‐treatment, treatment and post‐treatment periods. RESULTS: In the post‐treatment period, farms using sanitary measures had a higher control success with > 13% more bait boxes without feeding than farms not using sanitary measures. In addition, the reoccurrence of rats was delayed by 85 days. With increasing accessibility to buildings and more precise positioning of the boxes, control success improved, especially when rats could not spread from water‐bearing ditches through the sewer system, and when rat‐hunting animals were present. Resistant animals were more common indoors than outdoors, and there were more resistant rats recorded before and during treatment than in the post‐treatment period. CONCLUSION: The control success was substantially higher and reoccurrence was delayed using sanitary measures on farms. Sanitary measures can reduce resistance indirectly due to delayed re‐colonization and establishment of resistant populations inside buildings. Hence, sanitary measures help to reduce economic losses, rodenticides required for rat management and environmental risk especially in the resistance area. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess the potential of synthetic predatory cue containing sulphurous odours as an area repellent to reduce rodent damage. Groups of mature Rattus rattus of both sexes were exposed to 0.5%, 1% and 2% concentrations of 2,4,5-trimethylthiazole (TMTZ), a synthetic predatory cue, applied through cotton swab under laboratory and simulated indoor store conditions. Laboratory experiment revealed lower food consumption by rats from the treated side of chamber compared to the untreated side at all three concentrations of TMTZ exposed once in a week with up to 61.70% and 67.90% repellency in male and female rats, respectively. Daily exposure of TMTZ resulted in up to 84.90% repellency in males and 76.70% in females. Under simulated store conditions, 1% TMTZ exposed once completely prevented damage to treated bags containing wheat grains for up to 12 days in male and 14 days in female rats indicating sex-specific differences in response towards TMTZ. The present study suggests the potential of TMTZ in reducing damage caused by R. rattus under indoor storage conditions. [ABSTRACT FROM AUTHOR]

Alleles that introgress between species can influence the evolutionary and ecological fate of species exposed to novel environments. Hybrid offspring of different species are often unfit, and yet it has long been argued that introgression can be a potent force in evolution, especially in plants. Over the last two decades, genomic data have increasingly provided evidence that introgression is a critically important source of genetic variation and that this additional variation can be useful in adaptive evolution of both animals and plants. Here, we review factors that influence the probability that foreign genetic variants provide long-term benefits (so-called adaptive introgression) and discuss their potential benefits. We find that introgression plays an important role in adaptive evolution, particularly when a species is far from its fitness optimum, such as when they expand their range or are subject to changing environments. [ABSTRACT FROM AUTHOR]

Among invasive squirrels in Europe, the Siberian chipmunk Eutamias sibiricus, native to North-East Asia, shows the highest number of free-ranging populations in European countries, due to the intense pet trade it underwent between the 1960s and the 1980s. We describe 628-bp cytochrome b sequences from the Netherlands (N = 3), Belgium (N = 4) and Switzerland (N = 1), and through phylogenetic analysis show that they belong to the Korean subspecies. This confirms previous findings that the Korean subspecies (Eutamias sibiricus barberi) has been the most commonly introduced to Europe. Another subspecies (the Northern subspecies, Eutamias sibiricus sibiricus) has only been reported previously in an Italian free-living population. If the splitting of the Korean taxon as a proper species (Eutamias barberi) will be confirmed by analysis of nuclear markers, a revision of the European Regulation 1143/2014 should be conducted to explicitly ban the trade of newly identified taxa. [ABSTRACT FROM AUTHOR]

Treatments efficacy assessed for rodent incidence and tiller damage revealed that all the treatments caused significant reduction of rat live burrows and rat tiller damage over control. Integration of rodent management techniques in Module-1 (trapping-bromadiolone poison baiting - burrow smoking) and Module-2 (Zinc Phosphide poison baitingbromadiolone poison baiting-Aluminium Phosphide burrow application) found promising with significantly lowered rodent incidence and crop damage. % reduction in live burrows was 68.6 and 71.1 during 2017-18 and 61.8 and 65.8 during 2018-19 in Module-1 and 2, respectively. Tiller damage protection % was 65.9 and 68.9 in 2017-18 and 67.2 and 69.9 during 2018-19 for these treatments. Continuous application of rodenticides solo in M-5 (ALP) and M-4 (bromadiolone) also showed superior performance in containing the rodent damage and they are at par with the integrated treatments at certain crop stages. All the treatments recorded significant yield advantage over the control, but the benefit cost ratio were found relatively higher in the rodenticide treatments, highest (8:1) in the Module-2. [ABSTRACT FROM AUTHOR]

Insecticide resistance is a long‐standing problem affecting the efficacy and utility of crop protection compounds. Insecticide resistance also impacts the ability and willingness of companies around the world to invest in new crop protection compounds and traits. The Insecticide Resistance Action Committee (IRAC) was formed in 1984 to provide a coordinated response by the crop protection industry to the problem of insecticide resistance. Since its inception, participation in IRAC has grown from a few agrochemical companies in Europe and the US to a much larger group of companies with global representation and an active presence (IRAC Country Groups) involving an even wider array of companies in more than 20 countries. The focus of IRAC has also evolved from that of defining and documenting cases of insecticide resistance to a pro‐active role in addressing insecticide resistance management (IRM) providing an array of informational and educational tools (videos, posters, pamphlets) on insect pests, bioassay methods, insecticide mode of action and resistance management, all publicly available through its website (https://irac-online.org/). A key tool developed by IRAC is the Insecticide Mode of Action (MoA) Classification Scheme, which has evolved from a relatively simple acaricide classification started in 1998 to the far broader scheme that now includes biologics as well as insecticides and acaricides. A separate MoA Classification Scheme has also been recently developed for nematicides. The IRAC MoA Classification Scheme coupled with expanding use of MoA labeling on insecticide and acaricide product labels provides a straightforward means to implement IRM. An overview of the history of IRAC along with some of its notable accomplishments and future directions are reviewed. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The role of food‐producing environments in the emergence and spread of antimicrobial resistance (AMR) in EU plant‐based food production, terrestrial animals (poultry, cattle and pigs) and aquaculture was assessed. Among the various sources and transmission routes identified, fertilisers of faecal origin, irrigation and surface water for plant‐based food and water for aquaculture were considered of major importance. For terrestrial animal production, potential sources consist of feed, humans, water, air/dust, soil, wildlife, rodents, arthropods and equipment. Among those, evidence was found for introduction with feed and humans, for the other sources, the importance could not be assessed. Several ARB of highest priority for public health, such as carbapenem or extended‐spectrum cephalosporin and/or fluoroquinolone‐resistant Enterobacterales (including Salmonella enterica), fluoroquinolone‐resistant Campylobacter spp., methicillin‐resistant Staphylococcus aureus and glycopeptide‐resistant Enterococcus faecium and E. faecalis were identified. Among highest priority ARGs blaCTX‐M, blaVIM, blaNDM, blaOXA‐48-like, blaOXA‐23, mcr, armA, vanA, cfr and optrA were reported. These highest priority bacteria and genes were identified in different sources, at primary and post‐harvest level, particularly faeces/manure, soil and water. For all sectors, reducing the occurrence of faecal microbial contamination of fertilisers, water, feed and the production environment and minimising persistence/recycling of ARB within animal production facilities is a priority. Proper implementation of good hygiene practices, biosecurity and food safety management systems is very important. Potential AMR‐specific interventions are in the early stages of development. Many data gaps relating to sources and relevance of transmission routes, diversity of ARB and ARGs, effectiveness of mitigation measures were identified. Representative epidemiological and attribution studies on AMR and its effective control in food production environments at EU level, linked to One Health and environmental initiatives, are urgently required. [ABSTRACT FROM AUTHOR]

Wild rats are known to carry different microorganisms and are considered a reservoir of zoonotic pathogens worldwide. The urban rats were collected from five districts of Tehran and Gram-negative bacteria (GNB) were isolated from fecal samples and were identified using classical biochemical tests. The antibiotic susceptibility patterns of isolated bacteria were determined by Kirby–Bauer disk diffusion method, the results of which were interpreted in line with CLSI guideline. The frequency of antibiotic-resistant genes was identified using multiplex-PCR. Moreover, PCR method was used to identify the frequency of Escherichia coli O157:H7 and main categories of diarrheagenic E. coli including EPEC, ETEC, EIEC, EAEC, and STEC pathotypes. A total of 100 Rattus norvegicus were trapped and fecal samples were collected. Overall, 72 fecal samples were positive for GNB. E. coli (n = 46/72) had the highest frequency among the isolated GNB. Among E. coli isolates, the highest and lowest resistance rates belonged to ampicillin (56.5%) and ceftriaxone (0%), respectively. Klebsiella spp. was 100% resistant to imipenem, and streptomycin (0%) was the most effective antimicrobial agent on Klebsiella spp. Among surveyed genes, blaTEM (95.8%) and blaaadA-1 (58.3%) had the highest frequency, while blaKPC, and blaCMY-2 were not detected among Enterobacteriaceae. Herein, O157: H7 serotype was not detected and aEPEC (87%) was the most common pathotype detected. Results suggested that rodents might be a reservoir of antimicrobial-resistant pathogens and rodent control along with implementation of surveillance programs should be considered as a critical priority for urban health. [ABSTRACT FROM AUTHOR]

Well-known 4-hydroxycoumarin derivatives, such as warfarin, act as inhibitors of the vitamin K epoxide reductase (VKOR) and are used as anticoagulants. Mutations of the VKOR enzyme can lead to resistance to those compounds. This has been a problem in using them as medicine or rodenticide. Most of these mutations lie in the vicinity of potential warfarin-binding sites within the ER-luminal loop structure (Lys30, Phe55) and the transmembrane helix (Tyr138). However, a VKOR mutation found in Tokyo in warfarin-resistant rats does not follow that pattern (Leu76Pro), and its effect on VKOR function and structure remains unclear. We conducted both in vitro kinetic analyses and in silico docking studies to characterize the VKOR mutant. On the one hand, resistant rats (R-rats) showed a 37.5-fold increased IC 50 value to warfarin when compared to susceptible rats (S-rats); on the other hand, R-rats showed a 16.5-fold lower basal VKOR activity (V max /K m). Docking calculations exhibited that the mutated VKOR of R-rats has a decreased affinity for warfarin. Molecular dynamics simulations further revealed that VKOR-associated warfarin was more exposed to solvents in R-rats and key interactions between Lys30, Phe55, and warfarin were less favored. This study concludes that a single mutation of VKOR at position 76 leads to a significant resistance to warfarin by modifying the types and numbers of intermolecular interactions between the two. [Display omitted] • Mutation located outside of the binding pocket decreased the ligand-protein affinity. • Rats with mutated VKOR show a 37-fold higher IC 50 to warfarin than wild type rats. • Docking studies show that mutated VKOR has a lower affinity for warfarin in silico. • Mutated VKOR has weak interactions between binding sites in the loop and warfarin. [ABSTRACT FROM AUTHOR]

Abstract Background Due to the risk of spreading epizootic diseases through rodents, pest control is mandatory in pig farming in European countries. However, there is limited research focused on rodent control practices, usage of anticoagulant rodenticides, and the acceptance of Pest Control Operators (PCOs) in pig farming in Germany. Therefore, the present study aims to investigate current control practices in pig holdings and to analyze the potential of a financial support on the implementation of professional pest control. Results Data were collected from monitoring records of PCOs and personal interviews with farmers and PCOs. 33 of 47 farmers, who were offered the possibility to outsource rodent control to PCOs supported by financial contribution of the North Rhine-Westphalian Animal Disease Fund (TSK) for a period of 2 years, joined the project. Despite the widespread opinion that the professional would not be beneficial – the authors figured out that farmers could financially benefit in time saved and by improved rodent control measures from the work of the PCOs. Costs of pest control measures per operation on average did not differ significantly between costs incurred by employment of PCOs (1.310 € per year) and calculated costs that arise by farmers themselves (1.217 € per year). All PCOs used Difenacoum and Brodifacoum against pest infestations. In doing so, the infestation with rodents was reduced and most of the participating farmers assessed the project as successful and employ the PCOs permanently. However, mapping the farm locations to resistance areas of the Rodenticide Resistance Action Committee (RRAC) shows that Brodifacoum was frequently used in areas which are marked as areas that are at low risk or rather have no risk for resistance. The environmental risks, however, are increased in these areas. Conclusion The instrument of temporal start-up financing professional pest control allows ensuring the continuous engagement of PCOs after the project period. This could possibly lead to long-term effects on the individual farm hygiene and on disease prevention. Nevertheless, important research questions with regard to the application of anticoagulant rodenticides of farmers and PCOs in livestock farming and with regard to risk mitigation measures were generated, meriting further investigation.

Norway rats (Rattus norvegicus) cause extensive crop loss, infrastructure damage, and are vectors for zoonotic diseases. Due to reduced efficacy, environmental and animal welfare concerns related to traditional pest management tools, such as rodenticides, it is imperative to find new methods for controlling commensal rodents. Fertility control is emerging as a safe, humane, and effective method of long-term population management. Vinylcyclohexene diepoxide (VCD) and triptolide are 2 compounds that are known to target and inhibit ovarian function. Furthermore, triptolide debilitates spermatogenesis and sperm motility. We prepared liquid bait containing no active ingredients (control) or containing VCD (0.098%) and triptolide (0.0012%, treatment) and offered ad libitum for 56 days to male and female Norway rats placed in open, indoor arenas and allowed to breed for 4 rounds (a total of 138 days). The first 3 breeding rounds of treatment-matched matings produced fewer pups in the treatment rats compared to control rats (P < 0.001). In the fourth breeding round, control rats were cross-bred with treatment rats. There were no differences in pup numbers between these cross-breeding groups, but the litter sizes in both groups were smaller than those seen in the control female/control male matings. In addition to reduced pup numbers, treatment males and females exhibited decreased reproductive organ weights without any effect on adrenal, kidney, spleen, and liver weights compared to control rats. Use of a liquid contraceptive bait containing VCD and triptolide may be a suitable alternative to the traditional pest management tools used to control wild rat pest populations. [ABSTRACT FROM AUTHOR]

Brown rats are widespread in agroecosystems, but our understanding of factors affecting their activity is incomplete due to cryptic, nocturnal behaviours. Indirect monitoring methods include tracking plates and camera traps. Supplementary feeding of game birds may provide resources for rats away from farm buildings, allowing them to persist in winter when there is little other food available. Developing reliable methods to monitor such populations will facilitate landscape-scale studies of rat populations in farm environments and aid ecologically based approaches for controlling rats on farms. We compared camera traps and tracking plates to monitor brown rat activity near game bird feeders at a mixed farm in Northumberland, UK. Generalized linear models (GLM) were used to compare rat incidence estimated from camera traps and tracking plates. A strong positive relationship was found between the two methods, although tracking plate estimates were less reliable when rat activity was very low. Factors that affected populations of brown rats near game bird feeders were assessed via linear mixed-effect models (LMM) of monthly tracking plate data (October 2017 to September 2018). Populations were highest at the feeders (0 m) compared with further away (10 m, 20 m) and were also higher in periods of cold, wet weather and when more food was available from the feeders. Rodenticide application near feeders did not significantly affect activity, nor did land cover 100 m around each feeder. A highly significant relationship was detected with food supply, suggesting that the use of game bird feeders could potentially have major impacts on rat population dynamics. [ABSTRACT FROM AUTHOR]

Human–wildlife interactions, including human–wildlife conflict, are increasingly common as expanding urbanization worldwide creates more opportunities for people to encounter wildlife. Wildlife–vehicle collisions, zoonotic disease transmission, property damage, and physical attacks to people or their pets have negative consequences for both people and wildlife, underscoring the need for comprehensive strategies that mitigate and prevent conflict altogether. Management techniques often aim to deter, relocate, or remove individual organisms, all of which may present a significant selective force in both urban and nonurban systems. Management‐induced selection may significantly affect the adaptive or nonadaptive evolutionary processes of urban populations, yet few studies explicate the links among conflict, wildlife management, and urban evolution. Moreover, the intensity of conflict management can vary considerably by taxon, public perception, policy, religious and cultural beliefs, and geographic region, which underscores the complexity of developing flexible tools to reduce conflict. Here, we present a cross‐disciplinary perspective that integrates human–wildlife conflict, wildlife management, and urban evolution to address how social–ecological processes drive wildlife adaptation in cities. We emphasize that variance in implemented management actions shapes the strength and rate of phenotypic and evolutionary change. We also consider how specific management strategies either promote genetic or plastic changes, and how leveraging those biological inferences could help optimize management actions while minimizing conflict. Investigating human–wildlife conflict as an evolutionary phenomenon may provide insights into how conflict arises and how management plays a critical role in shaping urban wildlife phenotypes. [ABSTRACT FROM AUTHOR]

Cities are uniquely complex systems regulated by interactions and feedbacks between nature and human society. Characteristics of human society—including culture, economics, technology and politics—underlie social patterns and activity, creating a heterogeneous environment that can influence and be influenced by both ecological and evolutionary processes. Increasing research on urban ecology and evolutionary biology has coincided with growing interest in eco‐evolutionary dynamics, which encompasses the interactions and reciprocal feedbacks between evolution and ecology. Research on both urban evolutionary biology and eco‐evolutionary dynamics frequently focuses on contemporary evolution of species that have potentially substantial ecological—and even social—significance. Still, little work fully integrates urban evolutionary biology and eco‐evolutionary dynamics, and rarely do researchers in either of these fields fully consider the role of human social patterns and processes. Because cities are fundamentally regulated by human activities, are inherently interconnected and are frequently undergoing social and economic transformation, they represent an opportunity for ecologists and evolutionary biologists to study urban "socio‐eco‐evolutionary dynamics." Through this new framework, we encourage researchers of urban ecology and evolution to fully integrate human social drivers and feedbacks to increase understanding and conservation of ecosystems, their functions and their contributions to people within and outside cities. [ABSTRACT FROM AUTHOR]

Background: Humans routinely attempt to manage pest rodent populations with anticoagulant rodenticides (ARs). We require information on resistance to ARs within rodent populations to have effective eradication programs that minimise exposure in non-target species. Mutations to the VKORC1 gene have been shown to confer resistance in rodents with high proportions of resistance in mice found in all European populations tested. We screened mutations in Mus musculus within Western Australia, by sampling populations from the capital city (Perth) and a remote island (Browse Island). These are the first Australian mouse populations screened for resistance using this method. Additionally, the mitochondrial D-loop of house mice was sequenced to explore population genetic structure, identify the origin of Western Australian mice, and to elucidate whether resistance was linked to certain haplotypes. Results: No resistance-related VKORC1 mutations were detected in either house mouse population. A genetic introgression in the intronic sequence of the VKORC1 gene of Browse Island house mouse was detected which is thought to have originated through hybridisation with the Algerian mouse (Mus spretus). Analysis of the mitochondrial D-loop reported two haplotypes in the house mouse population of Perth, and two haplotypes in the population of Browse Island. Conclusions: Both house mouse populations exhibited no genetic resistance to ARs, in spite of free use of ARs in Western Australia. Therefore weaker anticoagulant rodenticides can be employed in pest control and eradication attempts, which will result in reduced negative impacts on non-target species. Biosecurity measures must be in place to avoid introduction of resistant house mice, and new house mouse subspecies to Western Australia. [ABSTRACT FROM AUTHOR]