Dissimilarity in flea and host assemblages and their interaction networks along a spatial distance gradient: different patterns revealed by different network dissimilarity metrics.

We investigated the distance-decay pattern (an increase in dissimilarity with increasing geographic distance) in regional assemblages of fleas and their small mammalian hosts, as well as their interaction networks, in four biogeographic realms. Dissimilarity of assemblages (ßtotal) was partitioned into species richness differences (ßrich) and species replacement (ßrepl) components. Dissimilarity of networks was assessed using two metrics: (a) whole network dissimilarity (ßWN) partitioned into species replacement (ßST) and interaction rewiring (ßOS) components and (b) D statistics, measuring dissimilarity in the pure structure of the networks, without using information on species identities and calculated for hosts-shared-by-fleas networks (Dh) and fleas-shared-by-hosts networks (Df). We asked whether the distance-decay pattern (a) occurs among interactor assemblages or their interaction networks; (b) depends on the network dissimilarity metric used; and (c) differs between realms. The ßtotal and ßrepl of flea and host assemblages increased with distance in all realms except for host assemblages in the Afrotropics. ßrich for flea and host assemblages increased with distance in the Nearctic only. In networks, ßWN and ßST demonstrated a distance-decay pattern, whereas ßOS was mainly spatially invariant except in the Neotropics. Correlations of Dh or Df and geographic distance were mostly non-significant. We conclude that investigations of dissimilarity in interaction networks should include both types of dissimilarity metrics (those that consider partner identities and those that consider the pure structure of networks). This will allow elucidating the predictability of some facets of network dissimilarity and the unpredictability of other facets.

Structure of compound and component communities of fleas parasitic on small mammals in six different regions as revealed by environmental-based co-occurrence geometry analyses.

We inferred the patterns of co-occurrence of flea species in compound (across all host species) and component (across conspecific hosts) communities from six regions of the world (Mongolia, Northwest Argentina, Argentinian Patagonia, West Siberia, Slovakia, and South Africa) using the novel eigenvector ellipsoid method. This method allows us to infer structural community patterns by comparing species' environmental requirements with the pattern of their co-occurrences. We asked whether: (a) communities are characterized by species segregation, nestedness, or modularity; (b) patterns detected by the novel method conform to the patterns identified by traditional methods that search for non-randomness in community structure; and (c) the pattern of flea species co-occurrences in component communities is associated with host species traits. The results of the application of the eigenvector ellipsoid method suggested that the co-occurrence of flea species was random in all compound communities except in South Africa, where this community demonstrated a tendency to be nested. Flea species co-occurrences were random in many component communities. Species segregation was detected in the flea community of one host, whereas the flea communities of 14 hosts from different regions appeared to be nested. No indication of a modular structure in any community was found. The nestedness of flea component communities was mainly characteristic of hosts with a low relative brain mass. We concluded that the application of this novel method that combines data on species distribution and their environmental requirements allows better identification of the community structural patterns and produces more reliable results as compared with traditional methods.

Epidemiological survey and genetic diversity of Bartonella in fleas collected from rodents in Fujian Province, Southeast China.

BACKGROUND: Fleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China. METHODS: From 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load. RESULTS: Bartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis. CONCLUSIONS: There is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns.

Functional similarity affects similarity in partner composition in flea-mammal networks.

Functional signal in an interaction network is a phenomenon in which species resembling each other in their traits interact with similar partners. We tested the functional signal concept in realm-specific and regional flea-host networks from four biogeographic realms and asked whether the species composition of (a) host spectra and (b) flea assemblages is similar between functionally similar flea and host species, respectively. Analogously to testing for phylogenetic signal, we applied Mantel tests to investigate the correlation between flea or host functional distances calculated from functional dendrograms and dissimilarities in sets of interacting partners. In all realm-specific networks, functionally similar fleas tended to exploit similar hosts often belonging to the same genus, whereas functionally similar hosts tended to harbour similar fleas, again often belonging to the same genus. The strength of realm-specific functional signals and the frequency of detecting a significant functional signal in the regional networks differed between realms. The frequency of detecting a significant functional signal in the regional networks correlated positively with the network size for fleas and with the number of hosts in a network for hosts. A functional signal in the regional networks was more frequently found for hosts than for fleas. We discuss the mechanisms behind the functional signal in both fleas and their hosts, relate geographic functional signal patterns to the historic biogeography of fleas and conclude that functional signals in the species composition of host spectra for fleas and of flea assemblages for hosts result from the interplay of evolutionary and ecological processes.

Searching for common patterns in parasite ecology: species and host contributions to beta-diversity in helminths of South African ungulates and fleas of South American rodents.

We searched for common patterns in parasite ecology by investigating species and host contributions to the beta-diversity of infracommunities (=assemblages of parasites harboured by a host individual) in helminths of three species of South African ungulates and fleas of 11 species of South American rodents, assuming that a comparison of patterns in distinctly different parasites and hosts would allow us to judge the generality or, at least, commonness of these patterns. We used data on species' composition and numbers of parasites and asked whether (i) parasite species' attributes (life cycle, transmission mode, and host specificity in helminths; possession of sclerotized combs, microhabitat preference, and host specificity in fleas) or their population structure (mean abundance and/or prevalence) and (ii) host characteristics (sex and age) affect parasite and host species' contributions to parasite beta-diversity (SCBD and HCBD, respectively). We found that parasite species' morphological and ecological attributes were mostly not associated with their SCBD. In contrast, parasite SCBD, in both ungulates and rodents, significantly increased with either parasite mean abundance or prevalence or both. The effect of host characteristics on HCBD was detected in a few hosts only. In general, parasite infracommunities' beta-diversity appeared to be driven by variation in parasite species rather than the uniqueness of the assemblages harboured by individual hosts. We conclude that some ecological patterns (such as the relationships between SCBD and parasite abundance/prevalence) appear to be common and do not differ between different host-parasite associations in different geographic regions, whereas other patterns (the relationships between SCBD and parasite species' attributes) are contingent and depend on parasite and host identities.

A RANGE-WIDE ECTOPARASITE SURVEY FOR ALLEGHENY WOODRATS (NEOTOMA MAGISTER).

Allegheny woodrats (Neotoma magister) are karst-specializing rodents that are rare or in conservation need in many states within their current range. Parasitism and habitat fragmentation have been suggested as primary reasons for declining populations. The presence, prevalence, and impact of ectoparasites, including fleas, ticks, and bots, is not fully understood rangewide. We collected Allegheny woodrat ectoparasites across 8 states in their range, identifying parasites via morphological and genetic means. Across contributions from 8 states, we discovered 2 woodrat-specific fleas parasitizing Allegheny woodrats: Orchopeas pennsylvanicus (all contributing states, n = 228) and Epitedia cavernicola (Indiana only, n = 9). The former was a new state record in New Jersey and Ohio. Woodrat specialists Ixodes woodi were morphologically identified as the dominant tick species (n = 38), and our contributions to genetic databases may ease confusion in future efforts. Three generalist species of ticks representing 8 individuals were identified as Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis. Only 2 bot fly species were recognized in Allegheny woodrats: 1 squirrel bot (Cuterebra emasculator) and 10 individuals of Cuterebra sp. not genetically conspecific to any known eastern U.S. rodent bot. The host specificity for fleas is not surprising, given that previous small-scale surveys and ticks primarily appear to be a mix of genus-specific (Ixodes woodi) and generalist species. There remains uncertainty with bots via morphological and genetic analyses. Our survey presents a wide-ranging baseline survey for Allegheny woodrats across their range, emphasizing the diversity (or specificity) of parasite groups for this species. An understanding of Allegheny woodrats and the health impact of ectoparasites is imperative because they face myriad challenges rangewide, especially considering the bot-driven demise of 1 woodrat in our study. Ectoparasites can have a marked impact on already-declining woodrat populations across their range and should not be overlooked in future surveys.

Relationships between functional alpha and beta diversities of flea parasites and their small mammalian hosts.

We studied the relationships between functional alpha and beta diversities of fleas and their small mammalian hosts in 4 biogeographic realms (the Afrotropics, the Nearctic, the Neotropics and the Palearctic), considering 3 components of alpha diversity (functional richness, divergence and regularity). We asked whether (a) flea alpha and beta diversities are driven by host alpha and beta diversities; (b) the variation in the off-host environment affects variation in flea alpha and beta diversities; and (c) the pattern of the relationship between flea and host alpha or beta diversities differs between geographic realms. We analysed alpha diversity using modified phylogenetic generalized least squares and beta diversity using modified phylogenetic generalized dissimilarity modelling. In all realms, flea functional richness and regularity increased with an increase in host functional richness and regularity, respectively, whereas flea functional divergence correlated positively with host functional divergence in the Nearctic only. Environmental effects on the components of flea alpha diversity were found only in the Holarctic realms. Host functional beta diversity was invariantly the best predictor of flea functional beta diversity in all realms, whereas the effects of environmental variables on flea functional beta diversity were much weaker and differed between realms. We conclude that flea functional diversity is mostly driven by host functional diversity, whereas the environmental effects on flea functional diversity vary (a) geographically and (b) between components of functional alpha diversity.

Immune Reactions of Vector Insects to Parasites and Pathogens.

This overview initially describes insect immune reactions and then brings together present knowledge of the interactions of vector insects with their invading parasites and pathogens. It is a way of introducing this Special Issue with subsequent papers presenting the latest details of these interactions in each particular group of vectors. Hopefully, this paper will fill a void in the literature since brief descriptions of vector immunity have now been brought together in one publication and could form a starting point for those interested and new to this important area. Descriptions are given on the immune reactions of mosquitoes, blackflies, sandflies, tsetse flies, lice, fleas and triatomine bugs. Cellular and humoral defences are described separately but emphasis is made on the co-operation of these processes in the completed immune response. The paper also emphasises the need for great care in extracting haemocytes for subsequent study as appreciation of their fragile nature is often overlooked with the non-sterile media, smearing techniques and excessive centrifugation sometimes used. The potential vital role of eicosanoids in the instigation of many of the immune reactions described is also discussed. Finally, the priming of the immune system, mainly in mosquitoes, is considered and one possible mechanism is presented.

Fleas of wild carnivores in Romania: diversity, distribution, and host-associations.

BACKGROUND: Fleas are important hematophagous insects, infesting mammals and birds with a worldwide distribution. Fleas of medical importance have been reported from various carnivores worldwide, such as felids, canids, or mustelids. Romania hosts a wide carnivore diversity, but very little is known about flea species that parasitize these animals in Romania. This study aimed to provide a better understanding of the fleas' diversity and their distribution in a relatively large and diverse number of wild carnivore hosts from Romania. METHODS: From 2013 to 2021, 282 carcasses of wild carnivores from different locations in Romania were collected and examined for the presence of ectoparasites. All collected fleas were morphologically identified using specific keys and descriptions. An analysis of the co-occurrence networks was performed. RESULTS: A total of 11 flea species were identified: Pulex irritans (41.09%), Paraceras melis (20.11%), Ctenocephalides felis (7.33%), Ctenocephalides canis (7.83%), Monopsyllus sciurorum (11.11%), Chaetopsylla trichosa (21.96%), Chaetopsylla homoea (5.5%), Chaetopsylla tuberculaticeps (100%), Chaetopsylla rothschildi (13.33%), Chaetopsylla sp. (14.34%), Chaetopsylla globiceps (5.12%), Echidnophaga gallinacea (10%). The statistical analyses showed a significant difference between the infestation of Martes foina with females being more frequently infected than males (66% versus 33%). Paraceras melis infesting Meles meles had a significantly higher prevalence in female badgers than in males (× 2 = 7.7977, P < 0.01) and higher intensities of infestations in males than in females (t = 1.871, P < 0.05). CONCLUSIONS: This is the first large-scale study investigating the distribution and diversity of flea species infesting wild carnivores in Romania. Three flea species were identified for the first time in Romania (E. gallinacea, C. homoea, and C. tuberculaticeps).

Metabolomic analysis to understand the mechanism of Ti3C2Tx (MXene) toxicity in Daphnia magna.

Due to their potential release into the environment, the ecotoxicity of Ti3C2Tx (MXene) nanomaterials is a growing concern. Unfortunately, little is known about the toxic effects and mechanisms through which Ti3C2Tx induces toxicity in aquatic organisms. The aim of this study is thus to investigate the toxic effects and mechanisms of Daphnia magna upon exposure to Ti3C2Tx with different sheet sizes (100 nm [Ti3C2Tx-100] and 500 nm [Ti3C2Tx-500]) by employing conventional toxicology and metabolomics analysis. The results showed that exposure to both Ti3C2Tx-100 and Ti3C2Tx-500 at 10 µg/mL resulted in a significant accumulation of Ti3C2Tx in D. magna, but no effects on the mortality or growth of D. magna were observed. However, the metabolomics results revealed that Ti3C2Tx-100 and Ti3C2Tx-500 induced significant changes in up to 265 and 191 differential metabolites in D. magna, respectively, of which 116 metabolites were common for both. Ti3C2Tx-100-induced metabolites were mainly enriched in phospholipid, pyrimidine, tryptophan, and arginine metabolism, whereas Ti3C2Tx-500-induced metabolites were mainly enriched in the glycerol-ester, tryptophan, and glyoxylate metabolism and the pentose phosphate pathway. These results indicated that the toxicity of Ti3C2Tx to D. magna has a size-dependent effect at the metabolic level, and both sheet sizes of Ti3C2Tx can lead to metabolic disturbances in D. magna by interfering with lipid and amino acid metabolism pathways.

New records of pathogenic bacteria in different species of fleas collected from domestic and peridomestic animals in Spain. A potential zoonotic threat?

Climate change is causing many vectors of infectious diseases to expand their geographic distribution as well as the pathogens they transmit are also conditioned by temperature for their multiplication. Within this context, it is worth highlighting the significant role that fleas can play as vectors of important pathogenic bacteria. For this purpose, our efforts focused on detecting and identifying a total of 9 bacterial genera (Rickettsia sp.; Bartonella sp.; Yersinia sp.; Wolbachia sp., Mycobacterium sp., Leishmania sp., Borrelia sp., Francisella sp. and Coxiella sp.) within fleas isolated from domestic and peridomestic animals in the southwestern region of Spain (Andalusia). Over a 19-months period, we obtained flea samples from dogs, cats and hedgehogs. A total of 812 fleas was collected for this study. Five different species were morphologically identified, including C. felis, C. canis, S. cuniculi, P. irritans, and A. erinacei. Wolbachia sp. was detected in all five species identified in our study which a total prevalence of 86%. Within Rickettsia genus, two different species, R. felis and R. asembonensis were mainly identified in C. felis and A. erinacei, respectively. On the other hand, our results revealed a total of 131 fleas testing positive for the presence of Bartonella sp., representing a prevalence rate of 16% for this genus identifying two species B. henselae and B. clarridgeiae. Lastly, both Y. pestis and L. infantum were detected in DNA of P. irritans and C. felis, respectively isolated from dogs. With these data we update the list of bacterial zoonotic agents found in fleas in Spain, emphasizing the need to continue conducting future experimental studies to assess and confirm the potential vectorial role of certain synanthropic fleas.

Essential oil pharmaceuticals for killing ectoparasites on dogs.

BACKGROUND: External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment. OBJECTIVES: The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella, citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils. METHODS: The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin. RESULTS: The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC50, LC90, and LC99) for the essential oils on tick larvae in 24 h were found to be low values. LC50, LC90, and LC99 for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects. CONCLUSIONS: This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment.

Detection of Rickettsia raoultii in Vermipsylla alakurt-Like Fleas of Sheep in Northwestern China.

INTRODUCTION: To date, a total of 2574 validated flea species have been discovered. Vermipsyllidae is a family of fleas that comprises at least eight species. Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Here a novel Vermipsylla species was described, and rickettsial agent was also detected in it. METHODS: A total of 128 fleas were collected directly from 260 pastured sheep in China. Of these, eight representative fleas (four males and four females) were identified by key morphological features. Meanwhile, 120 flea DNAs, including six flea samples for molecular taxonomy, were subjected to Rickettsia spp. DNA detection. The molecular identity of fleas was determined by amplification and sequenmce analysis of four genetic markers (the 28S rDNA genes, the 18S rDNA genes, the mitochondrial cytochrome c oxidase subunit I and subunit II). In addition, five Rickettsia-specific gene fragments were used to identify the species of the rickettsial agents. The amplified products were sequenced and phylogenetically analyzed. RESULTS: The morphological characteristics of the flea species identified in this study were similar to Vermipsylla alakurt, but presented difference in hair number of the metepimeron, the third tergum, the genitals and the tibiae of hind leg. The 18S rDNA, 28S rDNA and COII genetic markers from fleas showed the highest identity to those of V. alakurt, shared 98.45% (954/969), 95.81% (892/931) and 85.86% (571/665) similarities, respectively. However, the COI sequence showed the highest identity to that of Dorcadia ioffi with 88.48% (576/651) similarity. Rickettsia raoutii tested positive in 14.17% (17/120) flea DNA samples. CONCLUSION: Our study reports the detection of R. raoultii in V. alakurt-like fleas infesting sheep in China.

Morpho-molecular investigation of ectoparasitic infestation of companion animals in Sylhet city, Bangladesh.

Ticks (Ixodida) and Fleas (Siphonaptera) are considered among the most important arthropod of public health concern due to their ability to transmit vector-borne pathogens to humans. By sharing a common environment, vector-borne diseases constituted major setbacks to the development of a pet population in Bangladesh. This study aimed to determine companion animal-associated ticks and fleas based on morpho-molecular approaches. Between December 2021 and May 2022, 74 animals (62 cats and 12 dogs) were examined, of which 17 (27.4%) cats and 9 (75.0%) dogs had ectoparasitic infestations, with 35.1% overall prevalence. Morphometrical examination showed the ectoparasites in these animals were Ctenocephalides spp. (flea) and Riphicephalus spp. (tick). Genetic analysis using the mitochondrial markers i.e. Cytochrome c oxidase subunit 1 (cox1) revealed the presence of two flea species i.e., Ctenocephalides canis, Ctenocephalides felis, and one tick species Rhipicephalus sanguineus. Interviews of animal owners indicate that 35.14% of them had no concern about ectoparasitic infestation or ectoparasites-borne diseases. Our results indicated that fleas and ticks were the most common ectoparasites in companion animals of this area. The zoonotic nature of some ectoparasites can be regarded as a public health alert. The findings will assist epidemiologists and policymakers in offering customized guidance for upcoming monitoring and preventive tactics in this area.

Effects of Season, Habitat, and Host Characteristics on Ectoparasites of Wild Rodents in a Mosaic Rural Landscape.

Despite the large number of studies on rodent ectoparasites-most of them vectors of epidemiologically important pathogens-infestation patterns remain poorly understood in various ecological contexts, such as the highly patchy agricultural landscapes. We aimed to relate the infestation of rodents to temporal, habitat, and host variables. We assessed the difference in parasite prevalence and mean abundance depending on host sex, age, and body weight, season, and land use intensity. Furthermore, we analysed the effect of host species abundance and the differential responses of parasites in main and minor host species. The field survey was conducted in a rural landscape in southern Transylvania (Romania) between June and September 2010-2011. We live-trapped small mammals, collected the ticks and fleas, and recorded the presence of lice and mites. Overall, we found the same infestation patterns largely reported in the literature: higher prevalence and mean abundance in heavier adult males, significant seasonality and differences among host species, and evidence of the dilution effect. The uniqueness of our study system was the negative effect of the land use intensity on the prevalence and mean abundance of parasites, explained by the highly patchy mosaic landscape.

Nestedness of flea assemblages harboured by small mammalian hosts revisited: phylogenetic and functional nestedness do not follow compositional nestedness.

We studied compositional, phylogenetic, and functional nestedness in the flea assemblages of 14 host species across regions. Our main questions were (a) are a host's flea assemblages compositionally, phylogenetically, or functionally nested? (b) Do similar processes drive these nestedness facets? (d) Are a host's biological traits associated with nestedness of its flea assemblages? Rows of host matrices were ordered by decreasing species richness/the sum of the branch lengths of a phylogenetic tree/functional dendrogram or by decreasing region area or by increasing distance from the centre of a host's geographic range. None of the matrices sorted by species richness/sum of branch lengths were nested from a compositional perspective, but they were significantly nested from phylogenetic and functional perspectives. Compositional, phylogenetic, and functional nestedness of matrices sorted by region area or by distance from the host's geographic range centre varied between hosts. In some hosts, flea assemblages were nested from all three perspectives independently of how matrix rows were sorted, whereas in other hosts, the occurrence of significant nestedness depended on the order of the matrix rows. The degree of phylogenetic and functional nestedness for matrices sorted by the sum of branch lengths was associated with a host species' morphoecological traits and the latitude of its geographic range. We conclude that consideration of nestedness based solely on species composition does not allow a comprehensive understanding of the patterns of parasite community structure. Nestedness should also be considered from phylogenetic and functional perspectives.

Environment and traits affect parasite and host species positions but not roles in flea-mammal networks.

We studied spatial variation in the effects of environment and network size on species positions and roles in multiple flea-mammal networks from four biogeographic realms. We asked whether species positions (measured as species strength [SS], the degree of interaction specialization [d'], and the eigenvector centrality [C]) or the roles of fleas and their hosts in the interaction networks: (a) are repeatable/conserved within a flea or a host species; (b) vary in dependence on environmental variables and/or network size; and (c) the effects of environment and network size on species positions or roles in the networks depend on species traits. The repeatability analysis of species position indices for 441 flea and 429 host species, occurring in at least two networks, demonstrated that the repeatability of SS, d', and C within a species was significant, although not especially high, suggesting that the indices' values were affected by local factors. The majority of flea and host species in the majority of networks demonstrated a peripheral role. A value of at least one index of species position was significantly affected by environmental variables or network size in 41 and 36, respectively, of the 52 flea and 52 host species that occurred in multiple networks. In both fleas and hosts, the occurrence of the significant effect of environment or network size on at least one index of species position, but not on a species' role in a network, was associated with some species traits.

Molecular detection and characterization of Bartonella spp. in small mammals in the Amazonia and Cerrado biomes, midwestern Brazil.

Although Bartonella spp. have been worldwide described in rodents and bats, few studies have reported these agents in marsupials. The present work aimed to investigate the occurrence and genetic diversity of Bartonella in small mammals (rodents, marsupials, and bats) and associated ectoparasites in two ecoregions (Amazonia and Cerrado biomes) in midwestern Brazil. For this purpose, DNA samples from 378 specimens of small mammals (128 rodents, 111 marsupials, and 139 bats) and 41 fleas (Siphonaptera) were screened for the Bartonella genus employing a quantitative real-time PCR assay (qPCR) based on the nuoG (nicotinamide adenine dinucleotide dehydrogenase gamma subunit) gene. Then, positive samples in qPCR were submitted to conventional PCR (cPCR) assays targeting the gltA, ftsZ, and rpoB genes. One (0.78 %) rodent, 23 (16.54 %) bats, and 3 (7.31 %) fleas showed positive results in the qPCR for Bartonella sp. After cPCR amplification and sequencing, 13 partial Bartonella DNA sequences of the following genes were obtained only from bats´ blood samples: 9 gltA (citrate synthase), 3 ftsZ (cell division protein), and 1 rpoB (RNA polymerase beta subunit). The maximum likelihood inference based on the gltA gene positioned the obtained sequences in three different clades, closely related to Bartonella genotypes previously detected in other bat species and bat flies sampled in Brazil and other countries from Latin America. Similarly, the ftsZ sequences clustered in two different clades with sequences described in bats from Brazil, other countries from Latin America, and Georgia (eastern Europe). Finally, the Bartonella rpoB from a specimen of Lophostoma silvicolum clustered with a Bartonella sp. sequence obtained from a Noctilio albiventris (KP715475) from French Guiana. The present study provided valuable insights into the diversity of Bartonella genotypes infecting bats from two ecoregions (Amazonia and Cerrado) in midwestern Brazil and emphasized that further studies should be conducted regarding the description and evaluation of different lineages of Bartonella in wild small mammals and their ectoparasites in different Brazilian biomes.

Survey of flea infestation in cats and dogs in Western Andalusia, Spain: Seasonality and other risk factors for flea infestation.

This epidemiological survey aims to provide an update on the main flea species that parasitize domestic animals in the Western Andalusia assessing several ecological features that could be considered as possible risk factors for flea infestation. Over a 19-month period (June 2021 to January 2023), we obtained a total of 802 flea samples from 182 dogs (Canis lupus familiaris, Carnivora: Canidae, Linnaeus, 1758) and 78 cats (Felis silvestris catus, Carnivora: Felidae, Schreber, 1775). For each parasitized host, an epidemiological survey was completed, including the following information: geographical origin, age, sex, rural or urban habitat, type of animal's lifestyle (domestic or non-domestic), health status, cohabiting or not with other animals and the total number of collected fleas. The most common species was Ctenocephalides felis (Siphonaptera: Pulicidae) (Bouché, 1835) with a total of 713 specimens, which accounted for 89% of the total fleas. The second most abundant species was Pulex irritans (Siphonaptera: Pulicidae) (Linnaeus, 1758) with a total of 46 collected fleas (6% of the total). The remaining species identified were Archaeopsylla erinacei (Siphonaptera: Pulicidae) (Bouché, 1835) (25 specimens), Spilopsyllus cuniculi (Siphonaptera: Pulicidae) (Dale, 1878) (12 specimens) and Ctenocephalides canis (Siphonaptera: Pulicidae) (Curtis, 1826) (6 specimens), which accounted for 3%, 1% and 1%, respectively, of the total fleas collected. The months with the highest number of collected fleas were, in ascending order, May 2022, September 2021 and July 2021. Dogs had a greater diversity of flea species, and flea sex ratios were female biased in all identified species and among all studied hosts. Finally, we identified some potential host risk factors that promoted higher flea intensities, such as living in rural areas, or presenting other pathologies.

Ectoparasites of European hedgehogs (Erinaceus europaeus) in Germany and their health impact.

BACKGROUND: The European hedgehog (Erinaceus europaeus) is known for high levels of ectoparasitism that not only represents a health risk for the animals themselves, but also for pet animals and humans as hedgehogs are frequently taken into human care. In the present study, patterns of ectoparasite infestation were assessed in hedgehogs taken into care at northern German animal rehabilitation centres. METHODS: Ectoparasites (ticks, fleas and mites) of 498 hedgehogs were collected over a period of 3 years from July 2018 to May 2021. Species were identified based on morphological characteristics and also via amplification and sequencing of the partial cytochrome c oxidase subunit 2 (COX-2) gene for fleas of the family Ceratophyllidae. Seasonal changes in infestation patterns as well as correlations with animal age, body weight and health status were assessed using generalised linear models. RESULTS: Infestation with ticks, fleas and mites occurred throughout the year. Overall, 86.5% (431/498) of the examined hedgehogs were infested with ticks, 91.4% (455/498) with fleas and 17.7% (88/498) with mites. Ixodes ricinus and Ixodes hexagonus/Ixodes canisuga were the most common tick species detected, with the additional occurrence of one Ixodes frontalis. Significant seasonal changes were observed for I. ricinus, but not for I. hexagonus/I. canisuga. Additionally, I. ricinus nymph prevalence declined significantly as of 2020, probably as a consequence of the climate change-related drought as of 2018. In hedgehogs with flea infestations, Archaeopsylla erinacei, Ceratophyllus sciurorum, Nosopsyllus fasciatus and Ctenocephalides felis were identified. In all cases of mite infestation, Caparinia tripilis was detected, in addition to specimens of the family Macronyssidae and free-living mites of the family Acaridae. Statistical analyses showed correlations regarding the factors month, year, body weight and age, but no correlation was evident regarding the health status of the animals. CONCLUSIONS: With a detected infestation rate of 98.6%, almost all of the examined hedgehogs were infested with at least one ectoparasite species. The seasonal activity patterns of the different ectoparasite species together with the complex annual cycle of hedgehogs lead to different seasonal patterns in ectoparasite prevalence and infestation intensities. Due to the risk of transmission of zoonotic pathogens as well as the possible negative impact on the host itself, hedgehogs should be treated against ectoparasites when taken into care facilities.