RATTUS (Rat Thoracic Ultrasound): diagnosis of pneumothorax in pet rats.

Introduction: Rat thoracic ultrasound (RATTUS) is a non-invasive, easy-to-perform method for the evaluation of the pleural space and lungs in pet rats. The aim of the article is to present species-specific differences in the sonographic diagnosis of pneumothorax (PTX) in pet rats. Methods: In total, 158 client-owned pet rats were examined during the period from July 2023 to January 2024. PTX was diagnosed in 20 of the examined rats (13.25%, the age of the animals ranged from 2 months to 32 months (19.08 ± 6.93 months; mean ± SD) and their body weight ranged from 97 g to 885 g (461.27 ± 138.97 g; mean ± SD). Radiographic confirmation of PTX was performed in all these 20 rats, in the control group radiography was used to confirm that PTX was not present. Results: The lung point and the barcode sign was found in 7/20 animals with sensitivity of 33.3% (95% CI, 0.16-0.59) and specificity of 100% (95% CI, 0.97-1.0). The abnormal curtain sign was found in 19/20 of animals with the sensitivity of 95% (95% CI, 0.73-0.99.7) and the specificity of 89% (95% CI, 0.82-0.93). The abnormalities in the substernal access were in 17/20 of animals with the sensitivity of 85% (95% CI, 0.61-0.96) and the specificity of 71% (95% CI, 0.62-0.78). Discussion: In conclusion, RATTUS is a non-invasive method for the diagnosis of PTX in rats. Lung point and barcode sign are specific but not easily diagnosed signs. The curtain sign in RATTUS is not specific for PTX, as there are e.g. geriatric rats (rats older than 1,5 years) in which the abnormal curtain sign is visible without the presence of PTX. The presence of moderate to severe PTX can be assessed by the substernal approach based on the presence of cardiac displacement toward the collapsed lung lobe, and on evaluation of the lung inflation symmetry. This sign is not specific for PTX but in conjunction with other ultrasonic signs described makes the RATTUS a feasible tool for PTX diagnosis in rats.

Cardiotoxic Effects of Lachesis acrochorda Snake Venom in Anesthetized Wistar Rats.

Ophidism is a public health problem in tropical countries, occurring predominantly in rural areas. In Colombia, among the species responsible for snakebite envenomation, inflicting high mortality, is the Chocoan bushmaster, Lachesis acrochorda, better known locally by the names "verrugosa (warty)" and "pudridora (rot-causing)". In this research, the cardiotoxic effect of the venom of L. acrochorda in male Wistar rats weighing 230 ± 20 g was evaluated. A statistical design of randomized blocks was implemented with three treated groups, injected with lyophilized venom (doses of 3.22 µg/g, 6.43 µg/g, 12.86 µg/g), and a control group injected with 0.9% saline solution. Electrocardiographic (ECG) recordings were taken from the anesthetized animals, revealing an increase in the amplitude of the P and T waves and an increase in the duration of the QT intervals in the electrocardiographic recordings. These increases were not observed in the control biomodels. In the analysis of the CK and CK-MB enzyme levels, increases were also observed in the levels of cardiac isoenzymes in the injected animals, but none in the control animals. The histopathological analyses carried out reveal that the injected animals showed effects such as interfibrillar and perivascular edema, cellular shortening of the cardiomyocytes, foci with tissue destructuring, and necrosis with contraction bands. In conclusion, the venom of the Lachesis acrochorda snake increases the P and T waves and the QT interval and increases the CK and CK-MB enzymes in the blood. Additionally, it causes interfibrillar and perivascular edema in the cardiac tissue, cardiocytolysis, and contraction bands.

Dynamic movement patterns of commensal rodents Mastomys natalensis and Rattus rattus: determining differential habitat use using Rhodamine B.

BACKGROUND: Understanding movement patterns of rodent pests is essential for planning management strategies. Currently, for many rural village contexts, there is limited information on how rodents move between domestic and peridomestic areas, and the surrounding habitats. We investigated movement of the multimammate rat, Mastomys natalensis and the black rat, Rattus rattus in nine villages in Kilombero District, Tanzania. We used Rhodamine B (RhB) baits placed inside houses (R. rattus preferred habitat) in five villages and placed outside (M. natalensis preferred habitat) in four villages. RESULTS: Whilst both species were rarely captured in their nonpreferred habitat (5% M. natalensis inside houses; 23% R. rattus outside houses), evidence of RhB consumption when bait was in nonpreferred habitat was high for both species (50% M. natalensis; 57% R. rattus), indicating frequent movement to nonpreferred habitats. Whilst R. rattus movement distances were consistent with previous studies (maximum 81 m), within our village context, M. natalensis moved further (maximum 132 m) compared to previous published studies. Although bait consumption rates varied seasonally, we found no evidence that utilization of nonpreferred habitat varied seasonally. M. natalensis females moved into houses more frequently than males, whilst immature R. rattus moved outside houses more than mature individuals. CONCLUSION: These findings highlight the dynamic movement patterns of commensal rodents with implications for control and disease transmission. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

No evidence of mutations associated with anticoagulant resistance in gene Vkorc1 in brown and black rats from Barcelona.

Synanthropic rodents such as the brown rat (Rattus norvegicus) and black rat (Rattus rattus) are a source of disturbance in urban areas and the focus of control programs. Control measures often rely on anticoagulant rodenticides, but their broad use is compromised by the emergence of resistance. Here we studied the prevalence of anticoagulant resistance genotypes in the Vkorc1 gene in rats in the metropolitan area of Barcelona. In this area, part of the management practices to control brown rats include anticoagulant rodenticide use, but rodenticides with different active ingredients are used in rotation. Brown rats were sampled from the sewage system during two periods: from December 2016 to November 2017 when difenacoum and brodifacoum were used, and from August 2021 to July 2022 when bromadiolone was used. Because black rats have just recently been detected in Barcelona, we only studied them during the latter sampling period, with samples obtained from a control action carried out in a green urban area. Exon 3 of the Vkorc1 gene was characterized in both species, while exon 1 was additionally analyzed in black rats. Synonymous mutations, not resulting in amino-acid changes, were found in both exons, indicating no evidence of anticoagulant resistance in the rats of Barcelona. This finding indicates that the current rodent management plan in Barcelona, which involves anticoagulant rotation for brown rats and the use of life capture traps in specific situations for black rats, has helped to prevent the emergence of resistance to anticoagulant rodenticides in rats in Barcelona. Future actions should aim to diversify the control measures included in the rodent management plan.

Capillaria hepatica (syn. Calodium hepaticum) infection and factors influencing infection carriage in rats (Rattus spp.) in Hong Kong.

Capillaria hepatica (syn. Calodium hepaticum) (Bancroft, 1893) is a nematode, which colonises the liver of a wide range of hosts including humans. The worldwide prevalence of infection in the genus Rattus can be as high as 100% and the Norway rat (R. norvegicus) and black rat (R. rattus) are considered the main host species. This study is the first to investigate the epidemiology of C. hepatica infection in wild rats trapped in various geographical locations in Hong Kong. Four species of trapped rats were identified, with 65% being R. norvegicus, followed by 30% R. tanezumi (Asian house rat), 4% R. andamanensis (Sikkim rat), and 1% Niviventer huang (South China white-bellied rat). The overall prevalence of C. hepatica infection was 36.7% (81/221) (95% CI 30.4-43.4) and R. norvegicus was the most common rat species trapped during this study, with the highest prevalence of C. hepatica infection. Two risk factors for host infection were skin wounds and geographical region, whilst sex, body weight, stage of development, and presence of ectoparasites were not risk factors for this infection. Gross hepatic lesions were absent in 17% of infected rats and when present, were not pathognomonic for the infection. Infected rats lacked severe hepatic inflammation or fibrosis, indicating that rats tolerate the infection well. Egg production was observed in the livers of 69% of infected rats, which emphasizes their role as reservoirs of this zoonotic parasite. Several infected rats in this study were trapped inside residential buildings, which highlights the zoonotic risk of C. hepatica to humans following the potential ingestion of embryonated eggs from contaminated food, water, or soil.

Hematological and biochemical profiles, infection and habitat quality in an urban rat population.

Host condition is key in understanding disease dynamics. In an urban population of Rattus norvegicus, we aimed to assess whether infection of Leptospira interrogans and helminths was associated with patterns of host hematological and hormone-biochemical stress-related conditions. Rat kidney imprints and urine were used to identify and quantify L. interrogans, and feces samples for helminth eggs and corticosterone metabolites. Blood samples were taken for complete blood counts and specific biochemicals in rats' sera. Principal Component Analyses were performed to check whether rats would be grouped according to health profiles. We obtained hematological and hormone-biochemical data from 95 and 61 rats, respectively. Hematological PCA revealed distinct rat groups: typical (T), eosinophil deficient (Eos-D), eosinophil- and monocyte- deficient (EM-D) and monocyte deficient with high immature neutrophils (Mon-D). No association between L. interrogans or helminths and rat health profiles was observed, except with Trichiuridae, which mean intensity was significantly higher when all deficient groups were pooled together compared to the T-group. The poorest condition group was found in areas with fewer rat burrows than the T-group, indicating EM-D had a reduced ability to occupy "good" quality habitats. In natural populations, hematological profiles may reflect host's overall condition, instead of responses to specific infections.

Vkorc1 polymorphisms of the Norway rats in China: Implications for rodent management and evolutionary origin of anticoagulant resistance mutations.

The extensive utilization of second-generation anticoagulant rodenticides (SGARs) has raised concerns regarding non-target animal safety and environmental contamination. It is essential to assess the anticoagulant resistance level in rodent populations and prioritize the use of relative low toxic first-generation anticoagulant rodenticides (FGARs) in susceptible rodent populations. Mutations in the vitamin K epoxide reductase complex subunit 1 (Vkorc1) gene confer anticoagulant resistance in Norway rats. However, the Vkorc1 polymorphisms remain unclear in most Norway rat populations in China although anticoagulant rodenticides have been widely used in China since the 1980s. Analysis of the Vkorc1 polymorphisms in 489 rats across China, combined with in silico binding affinity analysis, revealed three potential resistance mutations A26T, C96Y, and A140T at three distinct locations. In the remaining locations, Vkorc1 resistance mutations were absent, indicating that the FGARs could be effective in these areas. Additional evolutionary analysis of different Vkorc1 mutations suggested that the three missense mutations identified in China might have evolved independently as de novo mutations, and the resistance mutations in Europe are unlikely to be pre-existing variations in China. Further analysis of Vkorc1 haplotypes among European resistant rat populations is essential for understanding the origin of these resistance mutations. These findings emphasize the importance of customizing rodent control strategies in China based on regional resistance levels and gaining insights into the origins of Vkorc1 mutations for more effective rodent management strategies.

The complete mitochondrial genome and phylogenetic analysis of Rattus tanezumi (Niethammer, 1975), captured from North China.

Rattus tanezumi (Niethammer, 1975) is one of the commensal rodent species in South China. With the development of transportation and climate change, R. tanezumi has gradually migrated north and become the dominant rat species for the past few years. In this study, we assembled a complete mitochondrial genome of R. tanezumi, captured from North China. The mitogenome contains 16,307 nucleotide pairs, including 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, as well as one non-coding control region. Based on whole mitogenome phylogenetical analysis showed that R. tanezumi captured from North China had a close phylogenetic relationship with that from Japan and South Korea. These findings are valuable for further studies on the evolution, genetic diversity, and taxonomy of Asian commensal rodent.

Status and analysis of undetected plague cases in Yunnan Province, China.

Background: The virulence of Yersinia pestis strains in the Rattus flavipectus plague focus is relatively low. The purpose of this study was to investigate the undetected, sporadic plague cases in plague foci and provide the basis for plague prevention and control. Methods: A 3-year-old plague-confirmed case was investigated in the R. flavipectus plague focus of Yunnan Province in 2020 due to the intensive screening for fever symptoms during the coronavirus disease 2019 (COVID-19) pandemic. Epidemiological investigation, laboratory testing, and clinical treatment were conducted for the case. The expanded survey was carried out around the case within a 7-km radius, including the resident population, domesticated dogs, and rats. PCR and indirect hemagglutination tests were performed on the collected samples. Results: The isolation rates of Y. pestis were 100.0% (7 out of 7) in dead rats and 4.00% (3 out of 75) in live rats in the survey area of the foci. A total of 5.00% (6 out of 120) of the domesticated dogs were F1 antibody positive. Nine local people were determined for plague infection recently (0.92%, 9 out of 978). The locations of human cases coincided with the Y. pestis epidemic area among the animals. Conclusion: This study discovered the existence of plague cases that had not been detected by routine surveillance in the R. flavipectus plague focus, and the actual epidemic of human infection may be underestimated.

Intraspecific Variation of Brown Rat Rattus norvegicus in Russia by D-Loop mtDNA Data.

For the first time in Russia, the intraspecific structure of the brown rat Rattus norvegicus was studied using the mitochondrial control region (D-loop) as a molecular marker. The mtDNA sequence was determined in brown rats from eight regions of European and Asian Russia. Three rat clades were identified, including one in European Russia and two in Asian Russia. The synanthropic subspecies R. n. norvegicus was found to have two, European and Asian, lineages. The European lineage included haplotypes from central and southern regions of Russia, and the Asian lineage included haplotypes from Eastern Siberia and the Russian Far East. The exoanthropic subspecies R. n. caraco from the Russian Far East formed a separate genetic lineage.

Comparative morphology of the rhinarium and upper lip in sigmodontine rodents: Refined nomenclature, intertribal variation in a phylogenetic framework, and functional inferences.

Rodents have received substantial attention in the study of olfaction. However, the rhinarium, the naked part of the nose, which plays an important role in chemical, tactile, and thermal perception, has been relatively overlooked. This study presents a comprehensive analysis of the rhinarium morphology and spatially associated structures (i.e., upper lip, and philtrum) in sigmodontines, a diverse group within the Cricetidae rodents. The research covers 483 specimens representing 145 species, accounting for 74% of genera in the clade, including all 13 recognized tribes, three incertae sedis genera, and the murid representatives Mus musculus and Rattus norvegicus. The inconsistent use of terminology in describing rhinarium traits across the literature poses a challenge for comparative analyzes. To address this issue, a standardized terminology was proposed to characterize the rhinarium. A paired complex protuberance typically with epidermal ridges (i.e., rhinoglyphics), termed here the tubercle of Hill, was identified as a distinctive feature in muroid rhinaria. Comparative assessments among tribes revealed unique sets of features defining each major clade, encompassing variations in hairiness, dorsum nasi complexity, size and positioning of the tubercle of Hill, and other key attributes. Two primary rhinarium configurations were discerned: one shared by Oryzomyalia and Sigmodontini and another specific to Ichthyomyini. The former groups display a ventrally positioned rhinarium prominently featuring the tubercle of Hill and sculptured areola circularis. In contrast, Ichthyomyini exhibit a frontally directed rhinarium characterized by an enlarged dorsum nasi fused to the tubercle of Hill, resulting in a distinctive "cherry" appearance. Convergent rhinarium structures observed in fossorial species, characterized by well-developed plica alaris and hair fringes, are presumed to mitigate potential damage during digging. Conversely, semiaquatic carnivorous sigmodontines showcase an integrated apical structure in their rhinarium, facilitating enhanced somatosensory capabilities crucial for predation activities during diving expeditions.

Brown rats (Rattus norvegicus) as potential reservoirs of Enterocytozoon bieneusi in Heilongjiang Province, China: high prevalence, genetic heterogeneity, and potential risk for zoonotic transmission.

Introduction: Enterocytozoon bieneusi, an obligatory intracellular fungus, is prevalent among animals and humans. Due to their close interaction with humans and their extensive regional distribution, brown rats (Rattus norvegicus) are important pathogen reservoirs. To assess the zoonotic transmission potential of E. bieneusi, a molecular investigation was conducted on 817 R. norvegicus from four cities in Heilongjiang Province, China. Methods: A total of 817 R. norvegicus were collected from four cities in Heilongjiang Province, China. The genotyping of E. bieneusi was conducted through PCR amplification of the small subunit ribosomal RNA (SSU rRNA)'s internal transcribed spacer (ITS) segments. Phylogenetic and similarity analyses were used to examine zoonotic potential and genetic characteristics of the E. bieneusi-positive specimens. Results: Among the 817 R. norvegicus, the total infection rate was 33.3% (272/817). Seventy-five genotypes were identified, including 14 known genotypes D (n = 167), A (n = 15), HLJ-CP1 (n = 12), WR8 (n = 6), EbpC (n = 2), BEB6 (n = 1), CS-4 (n = 1), CHPM1 (n = 1), Henan-II (n = 1), HNH-22 (n = 1), HNH-25 (n = 1), I (n = 1), JLD-XI (n = 1), SDD5 (n = 1), and 61 novel genotypes designated as SHWR1 (n = 10), SYSWR1 (n = 2), and SHWR2 to SHWR17, SYSWR2 to SYSWR36 and QTHWR1 to QTHWR8 (n = 1, each). Moreover, 10 samples exhibited mixed genotype infections, including D + A (n = 3), D + EbpC (n = 1), D + HLJ-CP1 (n = 1), D + SHWR1 (n = 1), D + SHWR16 (n = 1), D + SHWR17 (n = 1), SDD5 + WR8 (n = 1), and CS-4 + SYSWR36 (n = 1). Phylogenetic analysis grouped the genotypes into three main groups: group 1 (n = 67), group 2 (n = 5), and group 9 (n = 3). Discussion: The high prevalence and genetic diversity of E. bieneusi in Heilongjiang Province's R. norvegicus imply that these animals spread the pathogen. The R. norvegicus that E. bieneusi carries can spread zoonotic disease, making it a serious hazard to the local human population. Therefore, it is imperative to raise awareness about the dangers posed by R. norvegicus and implement measures to reduce their population to prevent environmental contamination.

Isolation of community-associated methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 30 from house rats (Rattus tanezumi) in Hong Kong.

Methicillin-resistant Staphylococcus aureus (MRSA) is of major public health concern due to its resistance to multiple antibiotics. This resistance has been observed in various settings, including hospitals and communities, and has been detected in both animals and humans. Although peridomestic rat species (Rattus spp.) are well described reservoirs of several human pathogens and antimicrobial resistant bacteria, little is known about their role in MRSA epidemiology. In order to investigate whether Rattus spp. in Hong Kong are potential carriers of MRSA, 221 rats were caught from various ecological areas and nasopharyngeal samples were cultured on MRSA selective media. Genotypic characteristics of MRSA were confirmed by whole genome sequencing. Two clonal sequence type (ST) 30 MRSA isolates, harbouring mecA on staphylococcal chromosome cassette (SCC) mec type IVc, were cultured from two house rats (Rattus tanezumi) caught in two densely populated urban areas. To the best of the authors' knowledge, this is the first detection of community-associated (CA)-MRSA strain ST30 SCCmec IVc in peridomestic rodents in Hong Kong and globally. Our finding indicates that house rats can be carriers of MRSA strains that are widely distributed in the community.

Are Rattus rattus fleas invasive? Evaluation of flea communities in invasive and native rodents in Chile.

Co-invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co-invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S-53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus' adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found.

Impacts of rainfall and rainfall anomalies on the population dynamics of rodents in southeast Asian rice fields.

BACKGROUND: The mechanisms that regulate multi-annual population dynamics of rodent pest species of cereal crops is often unknown. Better knowledge of such aspects can aid pest management and in turn improve food security and human health. The patterns and processes of the population dynamics of Rattus argentiventer, in rice fields of Indonesia, and Rattus tanezumi, in rice fields of the Philippines were assessed in this article. RESULTS: The meta-analysis of trapping data over 20 years in Indonesia, and 16 years in the Philippines indicated that rodent populations in rice fields did not show a regular multi-annual pattern. Rattus argentiventer populations in Indonesia responded to less rainfall from the current year. Rattus tanezumi populations in the Philippines responded positively to both rainfall and rainfall anomaly with a 1-year time lag. CONCLUSIONS: Our study of long-term population data indicates that certain combinations of rainfall parameters could be useful to predict years when there is higher rodent abundance in rice fields. The key rodent pest species in rice fields in Indonesia (R. argentiventer) and the Philippines (R. tanezumi) differ, and the populations of each species respond differently to rainfall anomalies. Other factors such as crop cover and water availability may also be important and should be considered in future work. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Reaching new lands: Updating the distribution of Angiostrongylus cantonensis in South America with the first record in Argentina.

BACKGROUND: Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in temperate areas and considered the leading cause of eosinophilic meningitis in humans. Synanthropic rodents such as Rattus norvegicus and Rattus rattus are the most frequent definitive hosts of this parasite. METHODS AND RESULTS: The presence of this parasite was detected in the pulmonary arteries of three specimens of R. norvegicus in the city of Buenos Aires representing the species' southernmost known record in natural hosts. Species confirmation was achieved through partial sequences of 18S and COI genes. By comparing the COI gene sequences with those available in GenBank through the construction of a haplotype network, we obtained that the analysed specimen presents high similarity with those reported in Japan and Southeast Asia. CONCLUSIONS: All infected rats were captured in an area surrounding a port with significant import and export activity, suggesting that A. cantonensis may have been introduced through commercial ships. Specifically, the parasite was detected in a neighbourhood with vulnerable socio-economic conditions and in a nature reserve, which exhibit biotic and abiotic characteristics conducive to sustaining high-density rat populations, scattered waste, areas of spontaneous vegetation, debris accumulation and flooded areas or lagoons offering suitable habitats for intermediate hosts such as snails. Thus, the close proximity of the port to these sites creates a favourable ecological context for the establishment of A. cantonensis. This study shows the need to conduct research to detect A. cantonensis in non-endemic areas but with the characteristics that promote its arrival and development of its life cycle in order to implement control measures to prevent expansion of this parasite and its transmission to humans and other animals.

Identification of Aichivirus in a Pet Rat (Rattus norvegicus) in Italy.

We investigated the occurrence of eight potential zoonotic viruses in 91 exotic companion mammals from pet shops in southern Italy via real-time PCR and end-point PCR. The animals were screened for aichivirus, sapovirus, astrovirus, hepatitis A, noroviruses (GI and GII), rotavirus, circovirus, and SARS-CoV-2. Among the nine species of exotic pets studied, only one rat tested positive for aichivirus. The high sequence similarity to a murine kobuvirus-1 strain previously identified in China suggests that the virus may have been introduced into Italy through the importation of animals from Asia. Since exotic companion mammals live in close contact with humans, continuous sanitary monitoring is crucial to prevent the spread of new pathogens among domestic animals and humans. Further investigations on detecting and typing zoonotic viruses are needed to identify emerging and re-emerging viruses to safeguard public health.

Technologies to Study Genetics and Molecular Pathways.

Over the last few decades, the study of congenital heart disease (CHD) has benefited from various model systems and the development of molecular biological techniques enabling the analysis of single gene as well as global effects. In this chapter, we first describe different models including CHD patients and their families, animal models ranging from invertebrates to mammals, and various cell culture systems. Moreover, techniques to experimentally manipulate these models are discussed. Second, we introduce cardiac phenotyping technologies comprising the analysis of mouse and cell culture models, live imaging of cardiogenesis, and histological methods for fixed hearts. Finally, the most important and latest molecular biotechniques are described. These include genotyping technologies, different applications of next-generation sequencing, and the analysis of transcriptome, epigenome, proteome, and metabolome. In summary, the models and technologies presented in this chapter are essential to study the function and development of the heart and to understand the molecular pathways underlying CHD.

Intramolecular Disulfide Bridges in Voltage-Dependent Anion Channel 2 (VDAC2) Protein from Rattus norvegicus Revealed by High-Resolution Mass Spectrometry.

Voltage-Dependent Anion Channel isoforms (VDAC1, VDAC2, and VDAC3) are relevant components of the outer mitochondrial membrane (OMM) and play a crucial role in regulation of metabolism and in survival pathways. As major players in the regulation of cellular metabolism and apoptosis, VDACs can be considered at the crossroads between two broad families of pathologies, namely, cancer and neurodegeneration, the former being associated with elevated glycolytic rate and suppression of apoptosis in cancer cells, the latter characterized by mitochondrial dysfunction and increased cell death. Recently, we reported the characterization of the oxidation pattern of methionine and cysteines in rat and human VDACs showing that each cysteine in these proteins is present with a preferred oxidation state, ranging from the reduced to the trioxidized form, and such an oxidation state is remarkably conserved between rat and human VDACs. However, the presence and localization of disulfide bonds in VDACs, a key point for their structural characterization, have so far remained undetermined. Herein we have investigated by nanoUHPLC/High-Resolution nanoESI-MS/MS the position of intramolecular disulfide bonds in rat VDAC2 (rVDAC2), a protein that contains 11 cysteines. To this purpose, extraction, purification, and enzymatic digestions were carried out at slightly acidic or neutral pH in order to minimize disulfide bond interchange. The presence of six disulfide bridges was unequivocally determined, including a disulfide bridge linking the two adjacent cysteines 4 and 5, a disulfide bridge linking cysteines 9 and 14, and the alternative disulfide bridges between cysteines 48, 77, and 104. A disulfide bond, which is very resistant to reduction, between cysteines 134 and 139 was also detected. In addition to the previous findings, these results significantly extend the characterization of the oxidation state of cysteines in rVDAC2 and show that it is highly complex and presents unusual features. Data are available via ProteomeXchange with the identifier PXD044041.

Older urban rats are infected with the zoonotic nematode Angiostrongylus cantonensis.

Rats, being synanthropic, are hosts to agents of zoonotic diseases that pose a threat to human and domestic animal health. The nematode parasite Angiostrongylus cantonensis, commonly known as the rat lungworm, is no exception; it can cause potentially fatal neural disease in humans, dogs and other species. The distribution of A. cantonensis (haplotypes SYD.1 and Ac13) and its close relative, Angiostrongylus mackerrasae is not well understood in Australia. We investigated the prevalence of Angiostrongylus in rats in Sydney, Australia, primarily via faecal qPCR, and identified the species and haplotypes using partial cox1 sequencing. We found a moderate prevalence of infection (29%; 95% CI: 16.1-46.6%) in black (Rattus rattus) and brown (Rattus norvegicus) rats around public parks and residential areas. This study demonstrates that Sydney's urban rat population is a reservoir for A. cantonensis. Modelling infection status as a function of rat species, sex, tibia length (as a proxy for age), and health index (a measure of weight by size) revealed that older rats are statistically more likely to be infected (χ 2 1 = 5.331, P = 0.021). We observed a dominant presence of the A. cantonensis SYD.1 haplotype, for which the implications are not yet known. No A. mackerassae was detected, leading us to suspect it may have a more restricted host- and geographical range. Overall, this study illustrates the presence and potential risk of A. cantonensis infection in Sydney. Public education regarding transmission routes and preventative measures is crucial to safeguard human and animal health.