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The article discusses the results of a special report on the complications arise in accidental ingestion of veterinary patients of bromethalin rodenticide conducted by Dr. Coppock. It mentions the propose intraosseos administration of lipid emulsion using a well-established protocol as therapeutic option for veterinary patients. It also suggests that animal healthcare providers who treat bromethalin-intoxicated veterinary patients with lipid emulsion should take into careful actions.

Brown rats are one of the most widespread urban species worldwide. Despite the nuisances they induce and their potential role as a zoonotic reservoir, knowledge on urban rat populations remains scarce. The main purpose of this study was to characterize an urban brown rat population from Chanteraines park (Hauts-de-Seine, France), with regards to haematology, population genetics, immunogenic diversity, resistance to anticoagulant rodenticides, and community of parasites. Haematological parameters were measured. Population genetics was investigated using 13 unlinked microsatellite loci. Immunogenic diversity was assessed for Mhc-Drb. Frequency of the Y139F mutation (conferring resistance to rodenticides) and two linked microsatellites were studied, concurrently with the presence of anticoagulant residues in the liver. Combination of microscopy and molecular methods were used to investigate the occurrence of 25 parasites. Statistical approaches were used to explore multiple parasite relationships and model parasite occurrence. Eighty-six rats were caught. The first haematological data for a wild urban R. norvegicus population was reported. Genetic results suggested high genetic diversity and connectivity between Chanteraines rats and surrounding population(s). We found a high prevalence (55.8%) of the mutation Y139F and presence of rodenticide residues in 47.7% of the sampled individuals. The parasite species richness was high (16). Seven potential zoonotic pathogens were identified, together with a surprisingly high diversity of Leptospira species (4). Chanteraines rat population is not closed, allowing gene flow and making eradication programs challenging, particularly because rodenticide resistance is highly prevalent. Parasitological results showed that co-infection is more a rule than an exception. Furthermore, the presence of several potential zoonotic pathogens, of which four Leptospira species, in this urban rat population raised its role in the maintenance and spread of these pathogens. Our findings should stimulate future discussions about the development of a long-term rat-control management program in Chanteraines urban park. [ABSTRACT FROM AUTHOR]

Background: Bartonella spp. are vector-borne pathogens transmitted to humans via blood-sucking arthropods. Rodents such as the black rat (Rattus rattus) and Norway rat (R. norvegicus) are thought to be the main reservoirs. An infection with rodent-associated Bartonella spp. may cause severe symptoms in humans such as endocarditis and neuroretinitis. The current knowledge of Bartonella prevalence in rats from western Europe is scarce. Methods: Rats and a few other rodent by-catches were trapped in the context of a rodenticide resistance study at different sites in Flanders, Belgium. During dissection, biometric data were collected, and spleen tissues were taken. DNA was extracted from spleen samples and tested for Bartonella spp. by conventional generic polymerase chain reaction (PCR). To determine the Bartonella species, a selected number of amplicons were sequenced and compared with GenBank entries. Results: In total, 1123 rodents were trapped. The predominate species was R. norvegicus (99.64%). Other rodents trapped included: two water voles (Arvicola amphibius, 0.18%); one colour rat (R. norvegicus forma domestica, 0.09%); and one muskrat (Ondatra zibethicus, 0.09%). PCR analysis of 1097 rodents resulted in 410 (37.37%, 95% CI: 34.50–40.31%) Bartonella spp. DNA-positive samples. Bartonella tribocorum (94.68%, 95% CI: 88.02–98.25%) was the most frequently detected Bartonella species, followed by B. grahamii (3.19%, 95% CI: 0.66–9.04%) and B. doshiae (1.06%, 95% CI: 0.03–5.79%). An uncultured Bartonella species occurred in one water vole (1.06%, 95% CI: 0.03–5.79%). There was a significantly higher Bartonella prevalence in older rats compared to juveniles and a significant difference in Bartonella prevalence concerning the localisation of trapping sites. In contrast, there was no statistically significant difference in Bartonella prevalence regarding sex, degree of urbanisation and season. Conclusions: Based on the high prevalence found, we conclude that the Norway rat seems to be a key reservoir host for zoonotic B. tribocorum in Belgium. [ABSTRACT FROM AUTHOR]

After the vkorc1 gene was first identified, changes occurring in the gene have been considered one of the main reasons of reduced susceptibility of house mice to anticoagulants. A no-choice feeding test was conducted according to standard EPPO (2004) methodology. Animals were fed for 21 days on baits containing difenacoum 0.005%. All animals were bromadiolone-resistant. Seven months earlier, all test animals had survived a 21-day bromadiolone (0.005%) no-choice feeding test, and sequencing of their vkorc1 gene had revealed the presence of Tyr139Cys and Leu1258Ser/Tyr139Cys VKOR variant. There were no survivors in the no-choice difenacoum feeding test. Consumption was not affected by VKOR variant, sex or genotype. A higher lethal dose was confirmed for Leu128Ser/Tyr139Cys than Tyr139Cys carriers, for females than males, and for homozygotes than heterozygotes. Our research showed that difenacoum 0.005% was effective against house mice carrying the Tyr139Cys VKOR variant, whether it occurred independently or in combination with the Leu128Ser variant in the Vkorc1 gene. [ABSTRACT FROM AUTHOR]

Despite the widespread use of anticoagulant rodenticides in baits for controlling commensal rodent pests, their application is problematic due to secondary intoxication and increasing resistance. In contrast to studies on Western European house mice (Mus musculus domesticus), few resistance studies have focused on Eastern European house mice (M. musculus musculus), which have a western distribution boundary in the Czech Republic. This study newly analysed the VKORC1 gene in M. m. musculus field populations from Czech farms and grain stores and identified a nonsynonymous mutation Tyr139Phe. This mutation was common throughout the Czech Republic and was present in 80.2% of the 86 individuals sampled. Additionally, all individuals exhibited a genotype with three synonymous mutations specific to the subspecies M. m. musculus. The functional (mortality–survival) response of the Tyr139Phe mutation was validated in a laboratory choice feeding test using bromadiolone-based bait, where all resistant homozygous individuals survived, while all susceptible mice died, with a mean survival of 6.9 days. [ABSTRACT FROM AUTHOR]

Museum collections serve as valuable repositories of biodiversity, offering a substantial amount of data and specimens for scientific research. This study describes the intrinsic value of the mammal collection at the National Museum of Natural History and Science of the University of Lisbon (Portugal) (MUHNAC), and its nationwide representativeness, with the final aim of revealing its potential to support research and conservation initiatives. The collection includes 6158 specimens, from 131 species, across 10 orders, the great majority collected within Portugal, although a small dataset mostly from other parts of Europe and Africa is also available. The most represented orders are Rodentia, Eulipotyphla, and Carnivora, in contrast to Chiroptera, Cetacea, and Artiodactyla. Approximately 40% of the species within these groups are of conservation concern according to both national and international conventions, with nearly 20% at risk of extinction based on IUCN criteria. Additionally, the representativity of species in MUHNAC reflects the museum's coverage of species records across the country, with smaller, non-threatened species being more prominently represented and larger, at-risk species being comparatively underrepresented. The influence of conservation, economic, legal, and ethical factors on the species spatial coverage is discussed, providing insights into the variability observed in museum collections. [ABSTRACT FROM AUTHOR]

In the context of evolutionary time, cities are an extremely recent development. Although our understanding of how urbanization alters ecosystems is well developed, empirical work examining the consequences of urbanization on adaptive evolution remains limited. To facilitate future work, we offer candidate genes for one of the most prominent urban carnivores across North America. The coyote (Canis latrans) is a highly adaptable carnivore distributed throughout urban and nonurban regions in North America. As such, the coyote can serve as a blueprint for understanding the various pathways by which urbanization can influence the genomes of wildlife via comparisons along urban–rural gradients, as well as between metropolitan areas. Given the close evolutionary relationship between coyotes and domestic dogs, we leverage the well-annotated dog genome and highly conserved mammalian genes from model species to outline how urbanization may alter coyote genotypes and shape coyote phenotypes. We identify variables that may alter selection pressure for urban coyotes and offer suggestions of candidate genes to explore. Specifically, we focus on pathways related to diet, health, behavior, cognition, and reproduction. In a rapidly urbanizing world, understanding how species cope and adapt to anthropogenic change can facilitate the persistence of, and coexistence with, these species. [ABSTRACT FROM AUTHOR]

Small rodents can cause problems on farms such as infrastructure damage, crop losses or pathogen transfer. The latter threatens humans and livestock alike. Frequent contacts between wild rodents and livestock favour pathogen transfer and it is therefore important to understand the movement patterns of small mammals in order to develop strategies to prevent damage and health issues. Miniaturised proximity loggers are a newly developed tool for monitoring spatial behaviour of small mammals. The strength of the Bluetooth Low Energy (BLE) signal can be used as an indicator of close contacts between wild rodents and livestock feeding sites, which is relevant for identifying possible transmission routes. This method study focussed on the use of the technology in an agricultural setting as well as dry runs for testing and calibrating this technology in farming environments used for animal husbandry. Results show that the battery life of the loggers was mainly influenced by the pre-set scan interval. Short scan intervals resulted in reduced battery lifespan and should be maximised according to the activity patterns of the target species. Habitat affects BLE signal strength resulting in higher signal strength indoors than outdoors. The height of the location of the loggers positively affected signal strength in livestock stables. Signal reception generally decreased with increasing distance and differed among loggers making calibration necessary. Within habitat specific distances, BLE proximity logging systems can identify contacts among small mammals and between animals and particular structures of interest. These results support the use of BLE based systems in animal husbandry environments and contribute to a body of evidence of validated techniques. In addition, such approaches can provide valuable insights into possible pathogen transmission routes. [ABSTRACT FROM AUTHOR]

Mutations in Exon 1, 2 and 3 of the vitamin K epoxide reductase complex subunit 1 (Vkorc1) gene are known to lead to anticoagulant rodenticide resistance. In order to investigate their putative resistance in rodenticides, we studied the genetic profile of the Vkorc1 gene in Turkish black rats (Rattus rattus) and brown rats (Rattus norvegicus). In this context, previously recorded Ala21Thr mutation (R. rattus) in Exon 1 region, Ile90Leu mutation (R. rattus, R. norvegicus) in Exon 2 region and Leu120Gln mutation (R. norvegicus) in Exon 3 region were identified as “missense mutations” causing amino acid changes. Ala21Thr mutation was first detected in one specimen of Turkish black rat despite the uncertainty of its relevance to resistance. Ile90Leu mutation accepted as neutral variant was detected in most of black rat specimens. Leu120Gln mutation related to anticoagulant rodenticide resistance was found in only one brown rat specimen. Furthermore, Ser74Asn, Gln77Pro (black rat) and Ser79Pro (brown rat) mutations that cause amino acid changes in the Exon 2 region but unclear whether they cause resistance were identified. In addition, “silent mutations” which do not cause amino acid changes were also defined; these mutations were Arg12Arg mutation in Exon 1 region, His68His, Ser81Ser, Ile82Ile and Leu94Leu mutations in Exon 2 region and Ile107Ile, Thr137Thr, Ala143Ala and Gln152Gln mutations in Exon 3 region. These silent mutations were found in both species except for Ser81Ser which was determined in only brown rats.

The Bonin Archipelago is a United Nations Educational, Scientific and Cultural Organization's World Natural Heritage Site in Japan with a unique ecosystem; however, the invasive rodents preying on endemic species have been a significant concern. The anticoagulant rodenticide, diphacinone, sprayed by the Ministry of the Environment, has succeeded; however, its repeated use leads to rodenticide resistance. This study evaluated the sensitivity by in vivo pharmacokinetics/pharmacodynamics (PK/PD) analysis and physiologically-based pharmacokinetic modeling to diphacinone in black rats (Rattus rattus) captured on the Bonin Archipelago in February 2022. The Bonin rats exhibited prolonged coagulation time after diphacinone administration. They recovered earlier than susceptible black rats, indicating that Bonin rats were less susceptible, though there were no genetic mutations in Vkorc1 , the target enzyme of diphacinone. After the administration of diphacinone, hepatic expression levels of Fsp1 , identified as the vitamin K reductase, was decreased, however, the Bonin rats exhibited the most minor suppression. The PK analysis showed that the excretion capacity of the Bonin rats was lower than that of the resistant black rats. In the PBPK modeling, the resistant black rats showed higher clearance than the Bonin and susceptible black rats due to high hepatic metabolic capacity. The Bonin rats demonstrated slow absorption and relatively low clearance. This study highlighted the reduced rodenticide-sensitive tendency of wild black rats in the Bonin Archipelago at an in vivo phenotype level. At the same time, they do not have known rodenticide resistance mechanisms, such as hepatic metabolic enhancement or Vkorc1 mutations. It is crucial to monitor the biological levels to evaluate rodenticide sensitivity accurately. [Display omitted] • Evaluation of rodenticide sensitivity in invasive rats in the Bonin Islands, Japan. • Bonin rats showed lower sensitivity characterized by prothrombin time measurement. • No genetic mutations in Vkorc1 : a target enzyme of rodenticides. • Bonin rats exhibited excretion capacities similar to those of sensitive rats. • Diphacinone treatment suppressed the expression of novel vitamin K reductase, Fsp1. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rat eradication from islands is a very effective tool that can free entire ecosystems from the pressure of alien predators. In this study we present the case study of Ventotene (Ponziane Archipelago, central Italy), which to date is the island with by far the greatest number of human inhabitants ever freed from the negative implications of rats. Rat eradication was carried out in the framework of the Life PonDerat project, co‐financed by the European Union. Besides considering the conservation benefits due to the removal of rats, we also considered the socio‐economic and pathogenic impacts from introduced rats. RESULTS: The overall economic cost of the rats was quantified to be at least €18 500 per year to the residents of the island. Several zoonotic pathogens were detected in the rat population prior to eradication. A reduction in the rodenticide distributed over time on the island was also estimated. Identifying the origin of the rat population allowed for the development of more targeted and effective biosecurity measures. The eradication effort was challenged by the presence of domestic animals and variability in support for baiting in urbanised areas. CONCLUSIONS: The results of this study open up new perspectives on island restoration projects. We demonstrated the cost‐effectiveness of the action, including ecosystem restoration, reduction of rat impacts in agricultural systems, and improving overall health and food safety. Our findings will have implications for similar interventions on other islands, potentially bringing significant benefits. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

We investigated the empirical evidence supporting chemical rodent control as a public health program via a systematic search of the scientific databases PubMed and Web of Science, searching with term-strings for the concepts: "rodent control" and "zoonotic disease." Retrieved results were screened by title and abstract to eliminate studies that (i) do not involve rodents, (ii) do not contain a zoonotic component, and (iii) involve rodents and zoonosis, but no rodent control. The remaining articles were read in full, eliminating studies that lack direct assessment of rodent control effects, with pre-/post-control measures of epidemiological outcomes. Overall, 957 entries were recovered, but only five passed all elimination criteria. Studies were concentrated in Iran, focusing on zoonotic cutaneous leishmaniasis control. The studies found significant effects on zoonotic incidence post-control, but achieved low scores in quality-of-report assessment. The effectiveness of chemical rodent control as a measure against a zoonotic disease is in its infancy, and more studies are necessary to allow an adequate assessment of the method. It is strongly recommended that future work in the subject should adopt standardized guidelines to report studies [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a quick, simple and inexpensive anticoagulant rodenticide resistance test method. The blood clotting response (BCR) test for resistance to chlorophacinone-Na in Mongolian Gerbils was prepared using small-volume blood samples. The normal Prothrombin time for Mongolian Gerbils was 9.92 ± 0.96 s using MDC Haemostasis thromboplastin-s (ISI: 1.86) reagent. Percent coagulation activity (PCA) calibration curves fitted the S curve and the PCA of 17% was found to correspond to a coagulation time International Normalized Ratio of 2.5. Dose-response baselines for BCR were obtained using susceptible Mongolian Gerbils and the ED99 values estimated for a quantal response were 0.27710 mg kg-1 for males and 0.26228 mg kg-1 for females. Based on the BCR test for resistance in wild Mongolian Gerbils from Zhenglanqi, Zhengxiangbaiqi, Kezhen in the Inner Mongolia Autonomous Region, we found that the populations of three areas have developed chlorophacinone-Na resistance populations with resistance ratios (%) of 34.0, 30.0 and 40.9, respectively. [ABSTRACT FROM AUTHOR]

Background: Rodent pests threaten agricultural cropping systems, impacting food security and small-holder farmers' income in cereal-growing areas., Results: This study investigated knowledge, attitude, and practices (KAPs) toward rodents infesting Moroccan cereal crops through a survey of 100 farmers in two regions (Rabat-Sale-Kenitra and Fes-Meknes). A constructive questionnaire about all rodent aspects was created and distributed to the farmers. Rodent infestation is perceived in most fields (80%), with Mus musculus (28%) and Rattus rattus (26%) being the most prevalent species. Farmers perceived rodents negatively (> 90%), considering them as a major threat. Most of the control attitudes against rodent infestation were positive when continuously established and promoted. The farmer profile was shown to influence rodent knowledge and control attitude. Younger, educated, and experienced farmers understood rodent damage trends better and adopted environmental-friendly management practices, while older, inexperienced respondents preferred to use rodenticides instead., Conclusion: The study revealed novel insights into rodent problems in Moroccan cereal fields and urged the need for ecologically-based rodent management (EBRM) practices. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

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We report on a genome-wide scan for introgression between the house mouse (Mus musculus domesticus) and the Algerian mouse (Mus spretus), using samples from the ranges of sympatry and allopatry in Africa and Europe. Our analysis reveals wide variability in introgression signatures along the genomes, as well as across the samples. We find that fewer than half of the autosomes in each genome harbor all detectable introgression, whereas the X chromosome has none. Further, European mice carry more M. spretus alleles than the sympatric African ones. Using the length distribution and sharing patterns of introgressed genomic tracts across the samples, we infer, first, that at least three distinct hybridization events involving M. spretus have occurred, one of which is ancient, and the other two are recent (one presumably due to warfarin rodenticide selection). Second, several of the inferred introgressed tracts contain genes that are likely to confer adaptive advantage. Third, introgressed tracts might contain driver genes that determine the evolutionary fate of those tracts. Further, functional analysis revealed introgressed genes that are essential to fitness, including the Vkorc1 gene, which is implicated in rodenticide resistance, and olfactory receptor genes. Our findings highlight the extent and role of introgression in nature and call for careful analysis and interpretation of house mouse data in evolutionary and genetic studies. [ABSTRACT FROM AUTHOR]

Norway rats (Rattus norvegicus) inhabit cities worldwide and live in close association with humans. Studies of urban rat zoonoses often rely on live-trapping, with fewer studies using rats sourced through lethal pest control interventions. Our objectives were to evaluate the utility of rats collected by pest control professionals for zoonotic pathogen surveillance and determine whether we could detect Leptospira interrogans and Streptobacillus moniliformis in pest control sourced rats. Rat carcasses were submitted from Windsor, Canada by pest control professionals between November 2018 and March 2020. Submissions were categorized by season and land use. Necropsies were performed to classify carcass quality, collect tissue samples, and record demographic data. The association between carcass quality and the ability to collect tissue samples for pathogen surveillance was assessed via an exact logistic regression model. Using PCR, a subset of kidney and spleen samples were tested for L. interrogans and S. moniliformis, respectively. Our sample of pest control sourced rats had similar sex and age distributions to those of live-trapping studies. Rats were primarily submitted from residential and industrial locations during fall, winter, and spring, which may reflect pest control service areas and peak business periods, rather than rat distribution. Of 124 submissions, 98 (79.0%) of rats showed only mild decomposition. The odds of collecting all tissue samples were reduced for fair compared to good-quality carcasses (OR: 0.029; 95% CI: 0-0.25; p = .0009) and for poor compared to fair-quality carcasses (OR: 0.048; 95% CI: 0.00085-0.53; p = .0065). Leptospira interrogans and S. moniliformis were detected in 9.1% (4/44) and 27.3% (15/55) of a subset of rats tested, respectively. Our results suggest that pest control sourced rats are suitable for surveillance for multiple zoonotic pathogens in urban environments. This method of rat collection may provide preliminary information to guide more detailed ecological studies., (© 2022 Wiley-VCH GmbH.)

Anticoagulant rodenticides (ARs) are used worldwide for the control of rodent pests and are the main method of control of rat pest populations in agricultural areas. The main aim of this review is to discuss the risk of ARs to non-target wildlife in oil palm areas in Southeast Asia, mainly Indonesia and Malaysia. We discussed AR use in oil palm areas and toxicities of ARs on target and non-target animals. We also reviewed published literature on wildlife species reported in oil palm areas in Southeast Asia and utilizing this information, we assessed the hazard risk of ARs to non-target wildlife in oil palm plantations. ARs are a secondary exposure hazard to rodent-consuming mammalian carnivores, such as leopard cats and civets, and rodent-consuming raptors, such as barn owls. Consumption of dead poisoned prey puts scavengers, such as water monitors, at high risk for AR exposure. Domestic livestock and granivorous birds are at high risk for AR exposure via primary exposure to toxic bait, while omnivores such as macaques and wild pigs are at moderate risk for both primary and secondary exposure to ARs. The effects of ARs on barn owls have been well studied in the field and in laboratory secondary toxicity studies. Thus, the nest-box occupancy and reproductive parameters of local barn owl populations can be monitored as an indicator of the AR exposure level in the area. CLINICAL TRIALS REGISTRATION: No clinical trials were involved in this study., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Central Eastern Asia, foremost the area bordering northern China and Mongolia, has been thought to be the geographic region where Norway rats (Rattus norvegicus) have originated. However recent fossil analyses pointed to their origin in southern China. Moreover, whereas analyses of fossils dated the species' origin as ∼1.2–1.6 million years ago (Mya), molecular analyses yielded ∼0.5–2.9 Mya. Here, to study the geographic origin of the Norway rat and its spread across the globe we analyzed new and all published mitochondrial DNA cytochrome-b (cyt-b; N = 156) and D-loop (N = 212) sequences representing wild rats from four continents and select inbred strains. Our results are consistent with an origin of the Norway rat in southern China ∼1.3 Mya, subsequent prehistoric differentiation and spread in China and Asia from an initially weakly structured ancestral population, followed by further spread and differentiation across the globe during historic times. The recent spreading occurred mostly from derived European populations rather than from archaic Asian populations. We trace laboratory strains to wild lineages from Europe and North America and these represent a subset of the diversity of the rat; leaving Asian lineages largely untapped as a resource for biomedical models. By studying rats from Europe we made the observation that mtDNA diversity cannot be interpreted without consideration of pest control and, possibly, the evolution of rodenticide resistance. However, demographic models explored by forward-time simulations cannot fully explain the low mtDNA diversity of European rats and lack of haplotype sharing with their source from Asia. Comprehensive nuclear marker analyses of a larger sample of Norway rats representing the world are needed to better resolve the evolutionary history of wild rats and of laboratory rats, as well as to better understand the evolution of anticoagulant resistance. [ABSTRACT FROM AUTHOR]

Background: Some rodent species living in arid areas show elevated physiological tolerance to anti-vitamin K rodenticides (AVKs), which seems to be due to some unknown selective pressures that rodents may experience in desert habitats. Genes involved in the ϒ-carboxylation of blood coagulation, including vitamin K epoxide reductase complex, subunit 1 (Vkorc1), ϒ-glutamyl-carboxylase (Ggcx) and NAD(P)H quinone one dehydrogenase (Nqo1) are associated with anticoagulant resistance, or some levels of elevated tolerance, in rodents. To detect whether the DNA sequences of the three genes are also under natural selection in the desert rodent species, we analyzed the Vkorc1, Ggcx and Nqo1 genes of the desert rodents and compared them with other rodent species., Results: We found an accelerated evolutionary rate in Vkorc1 of desert rodents, especially in Mus spretus, Nannospalax galili and Psammomys obesus. By contrast, signals of positive selection were absent for Ggcx and Nqo1 in all species. Mapping the amino acid variations on the VKORC1 protein three-dimensional model suggested most interspecific amino acid variations occur on the outer surface of the VKORC1 pocket, whereas most intraspecific amino acid changes and known AVK resistance mutations occurred on the inner surface and endoplasmic reticulum luminal loop regions. Some desert-species-specific amino acid variations were found on the positions where known resistance mutations occurred, indicating these variations might be related to the elevated physical tolerance to AVKs in desert rodents., Conclusion: The evolution of Vkorc1 has been accelerated in some desert rodent species, indicating genetic preadaptation to anticoagulant rodenticides. Positive selection and relaxed selection have been detected in Psammomys obesus and Nannospalax galili, indicating the two rodent species might also show tolerance to AVKs, which needs further verification. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Anticoagulant resistance was first discovered in UK Norway rats ( Rattus norvegicus Berk.) in 1958 and has been present ever since. The possible detrimental impact of resistance on effective rodent control was quickly recognised, and, for almost three decades, extensive research was conducted on the geographical distribution and severity of anticoagulant resistance in UK rats. Various schemes for the eradication of resistant rats were also implemented. At first, surveys showed resistance only to the first-generation anticoagulants, such as warfarin, chlorophacinone and coumatetralyl, but, later, resistance to the more potent second-generation anticoagulants, such as difenacoum and bromadiolone, was also discovered. Unlike some European countries, where only one or two resistance mutations occur, virtually all known rat resistance mutations occur in the United Kingdom, and five (Leu128Gln, Tyr139Ser, Tyr139Cys, Tyr139Phe and Leu120Gln) are known to have significant impacts on anticoagulant efficacy. Little is currently known of the geographical extent of anticoagulant resistance among Norway rats in the United Kingdom because no comprehensive survey has been conducted recently. At an operational level, anticoagulants generally retain their utility for Norway rat control, but it is impossible to control resistant rats in some areas because of restrictions on the use of the more potent resistance-breaking compounds. This paper reviews the development of resistance in Norway rats in the United Kingdom, outlines the present situation for resistance management and introduces a new resistance management guideline from the UK Rodenticide Resistance Action Group. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Rodents are mostly controlled by using anticoagulant rodenticides to minimise adverse effects along the food production chain. Genetic resistance to anticoagulant compounds occurs in populations of Norway rats (Rattus norvergicus) and other rodents throughout the world. This can be problematic for control operations and put predators and scavengers at risk because resistant prey individuals carry high anticoagulant loads. Single nucleotide polymorphisms (SNPs) in the vitamin K reductase complex subunit 1 (VKORC1) gene that are associated with rodenticide resistance are related to several pleiotropic effects including increased vitamin K requirement. The uptake of dietary vitamin K available from food sources present on farms including corn silage and garden herbs may mitigate such effects. We tested the preference for food rich in vitamin K1/3 in Norway rats susceptible or resistant to bromadiolone due to the homozygous amino acid variant Tyr139Cys. We also studied the effect of vitamin K consumption from several food sources on blood clotting in bromadiolone resistant and susceptible Norway rats. There was no general preference of rats for food sources rich in vitamin K. Surprisingly, there was no effect of vitamin K uptake on blood clotting times. However, the consumption of 4 of 5 corn silages prevented the rise in blood clotting times that otherwise occurred in vitamin K deficient bromadiolone resistant rats. This seemed to be due to substances with vitamin K activity present in silage and may contribute to the sustaining and spreading SNPs that are related to rodenticide resistance. As corn silage is becoming increasingly available to rats due to the expansion in generating bio-energy from corn silage, there may be a future increase in the occurrence of anticoagulant resistant Norway rats and associated problems in agro-ecosystems. [Copyright &y& Elsevier]

Accurate detection of invasive rodents is essential to guide appropriate management responses, including effective control. Due to the arboreal behaviour of some invasive rodent species, above-ground monitoring may provide managers with a clearer picture of rodent presence. Numerous ground-based rodent monitoring tools have been tested and compared, but how these tools perform in an arboreal context is unknown. Our study sought to compare the strata-specific detection capability of three widely applied rodent monitoring tools using a nested design. Over two month-long periods, we deployed 180 monitoring stations at the ground, mid-storey and canopy across 30 sites within a National Park forest. Each monitoring station consisted of a camera trap, chew card and tracking tunnel positioned to detect rodent presence. Device agreement was high, with all devices detecting rodent presence at 50% of stations. Chew cards were the most sensitive above-ground tool, implied by positive rodent detection 90% of the time, while tracking tunnels and camera traps generated a positive detection 74% and 75% of the time respectively. Low equipment costs also made chew cards the most cost-effective method. Detection performance differed according to the strata in which the device was deployed, thus a combination of methods that includes camera traps and chew cards was most effective when implementing a three-dimensional rodent monitoring network in forests. While not all methods are equal, traditionally ground-based rodent monitoring devices can be used to effectively monitor arboreal rodent activity. We provide evidence-based guidance for invasive rodent monitoring in an arboreal context to support future invasive rodent population control or eradication programs. [ABSTRACT FROM AUTHOR]

Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent populations. The current study is the first to assess the antifertility effects of quinestrol in male lesser bandicoot rat, Bandicota bengalensis which is the predominant rodent pest species in Southeast Asia. Rats in different groups were fed bait containing 0.00%, 0.01%, 0.02%, and 0.03% quinestrol for 10 days in laboratory and evaluated immediately, and 15, 30, and 60 days after treatment discontinuation for effect on reproduction and other antifertility parameters. Effect of 0.03% quinestrol treatment for 15 days was also observed in managing rodent populations in groundnut crop fields. Treatment resulted in average consumption of 19.53 ± 1.80, 67.63 ± 5.50, and 246.67 ± 1.78 mg/kg bwt active ingredient by three treated groups of rats, respectively. No reproduction was observed in female rats mated with male rats treated with 0.03% quinestrol, even 30 days after cessation of treatment. Post‐mortem examination showed a significant (P < 0.0001) effect of treatment on organ weights (testis, cauda epididymis, seminal vesicles, and prostate gland) and different sperm parameters (sperm motility, sperm viability, sperm count, and sperm abnormality) in the cauda epididymal fluid with partial reversibility after 60 days. A significant (P < 0.0001) effect of quinestrol on the histomorphology of testis and cauda epididymis was observed, suggesting its effect on spermatogenesis. Affected cell association and cell count in seminiferous tubules did not fully recover within 60 days of stopping treatment. Evaluation of the effects of quinestrol treatment in groundnut fields showed greater reductions in rodent activity in fields treated with 2% zinc phosphide followed by 0.03% quinestrol treatment as compared to fields treated with 2% zinc phosphide alone. Research concludes that quinestrol has the potential to reduce fecundity and post control rebuildup of B. bengalensis populations, but long‐term studies of the effectiveness of quinestrol under large‐scale field conditions are needed to use it as part of an integrated pest control program for rodents. [ABSTRACT FROM AUTHOR]

Background: Rodent management with lethal methods (e.g., rodenticides) comes with downsides for rodent welfare, the environment and non-target species. To reduce chemical use and prevent rodent nuisance, pest controllers in the Netherlands must work according to the principles of integrated pest management (IPM). A condition for the success of IPM is that there is sufficient engagement of all parties involved, including clients of pest controllers. The aim of this study was to gain insight into the attitudes of clients regarding rodent control, IPM and the application of preventive measures. Insight into their attitudes may contribute to a better implementation of IPM and with that to a more sustainable rodent management based on more effective prevention. An online survey among 248 clients of Dutch pest controllers from both the agricultural and other sectors was carried out., Results: Respondents from the agricultural sector had a relatively negative attitude towards IPM, the new IPM regulations in the Netherlands and had little confidence in prevention. In other sectors, respondents were more positive about IPM and had more confidence in prevention. The respondents from the latter subgroup had a similar attitude compared to Dutch pest controllers who participated in a previous survey., Conclusion: The findings of the study provide information for the further development and practical implementation of IPM and preventive measures and with that a more sustainable and animal friendly rodent management. They can also be helpful for a better communication and cooperation between pest controllers and their clients. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Grassland is not only an important part of the terrestrial ecosystem with multiple ecological functions, but also an important base for Chinese herdsmen to produce and live. However, the occurrence and spread of rodent infestation reduces the biodiversity and productivity of grassland ecosystems. It also severely threatens human life, health, and biosecurity through disease transmission. In this study, we explored the ability of the nanocomposite sterilant ND-1 to control grassland rodent populations. Semi-closed experimental and control plots were established in the desert area of Alashan, Inner Mongolia, China. In spring 2018, the nanocomposite sterile ND-1 (Nongda-1) was introduced once, and the control effect of ND-1 on the growth of the wild population of midday gerbils was measured for two years. We show that ND-1 significantly reduced the population of midday gerbils in the experimental area, with a negative population growth rate. In addition, in the second year, the ratio of female midday gerbils to sub-adults in the experimental area was significantly lower than that in the control area, which resulted in a significant difference in the sex ratio of midday gerbils. There were significantly fewer females than males, and the population growth of midday gerbils in the experimental area was significantly inhibited. ND-1 had no significant effect on the home range of midday gerbils, and sterile individuals continued to occupy the home range and consume resources. Therefore, ND-1 reduced the number of female midday gerbils during the breeding period and the sex ratio and population density and altered the age structure of the wild population. Additionally, competition between sterile and normal individuals had a significant control effect on the growth of wild populations. Our studies demonstrate the significance of ND-1 in the sustainable control of grassland rodent pests, with the potential for limiting grassland rodent damage in the future. [ABSTRACT FROM AUTHOR]

The management of invasive species has been greatly enhanced by population genetic analyses of multilocus single-nucleotide polymorphism (SNP) datasets that provide critical information regarding pest population structure, invasion pathways, and reproductive biology. For many applications there is a need for protocols that offer rapid, robust and efficient genotyping on the order of hundreds to thousands of SNPs, that can be tailored to specific study populations and that are scalable for long-term monitoring schemes. Despite its status as a model laboratory species, there are few existing resources for studying wild populations of house mice (Mus musculus spp.) that strike this balance between data density and laboratory efficiency. Here we evaluate the utility of a custom targeted capture genotyping-by-sequencing approach to support research on plaguing house mouse populations in Australia. This approach utilizes 3,651 hybridization capture probes targeting genome-wide SNPs identified from a sample of mice collected in grain-producing regions of southeastern Australia genotyped using a commercially available microarray platform. To assess performance of the custom panel, we genotyped wild caught mice (N = 320) from two adjoining farms and demonstrate the ability to correctly assign individuals to source populations with high confidence (mean >95%), as well as robust kinship inference within sites. We discuss these results in the context of proposed applications for future genetic monitoring of house mice in Australia. [ABSTRACT FROM AUTHOR]

On a planet experiencing constant human population growth, it is necessary to explore the anthropogenic effects on the genetic diversity of species, and specifically invasive species. Using an analysis that integrates comparative phylogeography, urban landscape genetics, macrogenetics and a systematic review, we explore the worldwide genetic diversity of the human commensal and anthropogenic species Rattus rattus and Rattus norvegicus. Based on metadata obtained considering 35 selected studies related to observed heterozygosity, measured by nuclear molecular markers (microsatellites, Single Nucleotide Polymorphisms—SNPs-, restrictition site-associated DNA sequencing -RAD-Seq-), socioeconomic and mobility anthropogenic factors were used as predictors of genetic diversity of R. rattus and R. norvegicus, using the Gini index, principal component analysis and Random Forest Regression as analysis methodology. Population density was on average the best predictor of genetic diversity in the Rattus species analyzed, indicating that the species respond in a particular way to the characteristics present in urban environments because of a combination of life history characteristics and human-mediated migration and colonization processes. To create better management and control strategies for these rodents and their associated diseases, it is necessary to fill the existing information gap in urban landscape genetics studies with more metadata repositories, with emphasis on tropical and subtropical regions of the world. [ABSTRACT FROM AUTHOR]

Second-generation anticoagulant rodenticides potentially build persistent residues in animals and accordingly pose a risk of secondary poisoning. We examined the effect of a low concentration of cholecalciferol in brodifacoum bait on bait consumption by Norway rats (Rattus norvegicus Berkenhout 1769) and on the control success in a laboratory study and in field trials. Additionally, the efficacy of both baits was determined against resistant Y139C rats. Cholecalciferol caused a strong stop-feed effect after two days in the laboratory study. On two field study sites each, bait containing either 25 mg kg−1 brodifacoum or 25 mg kg−1 brodifacoum and 100 mg kg−1 cholecalciferol was applied to treat infestations of Norway rats. Infestations were assessed pre- and post-treatment. Rats were radio-tagged, and carcasses were searched for during the treatment period. DNA of each rat was genotyped to determine the resistance status conferred by the VKORC1 gene. On all farms, control success exceeded 90%. On farms treated with brodifacoum only, the ratio of total bait consumption to pre-treatment census was significantly higher (6.6 and 4.8 times) than on farms treated with the combination (2.7 and 2.9 times). 78.8% of 183 rats were confirmed Y139C resistant. Bait ingestion was reduced by almost fifty per-cent when cholecalciferol was added to the bait with no impact on control success. All treatments resulted in control levels exceeding 90%, despite a high proportion of anticoagulant-resistant rats. When the use of highly toxic compounds is required in resistance management, addition of cholecalciferol to these baits may reduce the transfer of residues to the environment. [ABSTRACT FROM AUTHOR]

Seoul orthohantavirus (SEOV) is a rat-associated zoonotic pathogen with an almost worldwide distribution. In 2019, the first autochthonous human case of SEOV-induced hemorrhagic fever with renal syndrome was reported in Germany, and a pet rat was identified as the source of the zoonotic infection. To further investigate the SEOV reservoir, additional rats from the patient and another owner, all of which were purchased from the same vendor, were tested. SEOV RNA and anti-SEOV antibodies were found in both of the patient's rats and in two of the three rats belonging to the other owner. The complete coding sequences of the small (S), medium (M), and large (L) segments obtained from one rat per owner exhibited a high sequence similarity to SEOV strains of breeder rat or human origin from the Netherlands, France, the USA, and Great Britain. Serological screening of 490 rats from breeding facilities and 563 wild rats from Germany (2007–2020) as well as 594 wild rats from the Netherlands (2013–2021) revealed 1 and 6 seropositive individuals, respectively. However, SEOV RNA was not detected in any of these animals. Increased surveillance of pet, breeder, and wild rats is needed to identify the origin of the SEOV strain in Europe and to develop measures to prevent transmission to the human population. [ABSTRACT FROM AUTHOR]

Simple Summary: Current trends of human population growth and landscape development in Europe suggest that wildlife impacts will increase. Traditional methods to mitigate these impacts, such as culling, can be ineffective, environmentally harmful and often publicly opposed. Contraceptives might be an alternative to culling. This review focuses on contraceptives for mammals and birds, currently registered or widely tested, which might be considered for European wildlife. The review describes the effects of contraceptives on reproduction and welfare, the methods and challenges of contraceptive administration to large numbers of animals, the potential cost and feasibility of using fertility control and the knowledge gaps in this area. Contexts and species for using contraceptives to reduce the impacts of European wildlife include small, isolated wildlife populations, charismatic species and situations in which lethal control is either illegal or publicly unacceptable, such as urban environments and national parks. The review provides guidance to assist decisions about the potential use of wildlife fertility control and lists eight main reasons for Europe to invest in this area, and particularly in developing oral contraceptives which will allow large-scale applications of wildlife fertility control. This would be crucial for Europe, where humans and wildlife are increasingly sharing space and resources. Trends of human population growth and landscape development in Europe show that wildlife impacts are escalating. Lethal methods, traditionally employed to mitigate these impacts, are often ineffective, environmentally hazardous and face increasing public opposition. Fertility control is advocated as a humane tool to mitigate these impacts. This review describes mammalian and avian wildlife contraceptives' effect on reproduction of individuals and populations, delivery methods, potential costs and feasibility of using fertility control in European contexts. These contexts include small, isolated wildlife populations and situations in which lethal control is either illegal or socially unacceptable, such as urban settings, national parks and areas where rewilding occurs. The review highlights knowledge gaps, such as impact of fertility control on recruitment, social and spatial behaviour and on target and non-target species, provides a decision framework to assist decisions about the potential use of wildlife fertility control, and suggests eight reasons for Europe to invest in this area. Although developing and registering contraceptives in Europe will have substantial costs, these are relatively small when compared to wildlife's economic and environmental impact. Developing safe and effective contraceptives will be essential if European countries want to meet public demand for methods to promote human–wildlife coexistence. [ABSTRACT FROM AUTHOR]

Rats are abundant in the urban ecosystem, posing concerns for public health, infrastructural damage, and negative impacts for other urban wildlife. Sewers are considered to be one of the main reservoirs for urban rat populations, and rats may migrate between sewers and other surface areas in search of food and harbouring sites. Yet the ecology of rats in sewers has received little attention. To address this knowledge gap, this review identifies a number of sewer ecosystem characteristics that have been associated with rat activity. We demonstrate that sewers with narrower pipes, lower flow rates, and construction materials, such as brick and clay, are associated with more rat activity. Further, this review suggests that poorly maintained sewers may contain more crevices and cracks for rats to burrow, leading to greater levels of infestation. Finally, we find that sewers located in residential areas, or closer to food establishment, are more prone to rat presence. Together, these findings uncovered several significant implications for management of rats in sewers, as well as highlight the need for these characteristics to be considered in the urban planning process. Future work is needed to explore how rats in sewers and their management impact above ground populations of rats and other urban wildlife. [ABSTRACT FROM AUTHOR]

The article discusses about research on cognitive abilities and innovation propensity in small mammals, particularly ground-dwelling rodents, in urban environments with drastic environmental changes. Topic include the study explores the drivers of behavioral variation, individual differences in innovation propensity, and the role of animal personality in mediating cognitive performance, highlighting the importance of such traits in adapting to human-altered environments.