Medical and Veterinary Entomology最新文献

This study analysed the presence of Rickettsia (Rickettsiales: Rickettsiaceae) in fleas (Siphonaptera) associated with cricetid rodents in periurban localities of Gran La Plata, Argentina. Rodents were captured in three localities and fleas were collected directly from their fur. After DNA extraction, fleas were prepared for microscopic identification. PCR amplification of gltA and ompB genes was performed on each individual flea to detect and identify Rickettsia. The OmpB gene was sequenced and compared using nBLAST to initially identify its similarity with other sequences from GenBank. A phylogenetic tree was constructed to evaluate the relationships of the sequences obtained with others deposited in GenBank. Out of the 253 cricetids (seven species) captured, 87 fleas (four species) were collected. Of them, 10 fleas (11.5%) tested positive for Rickettsia. According to nBLAST and the phylogenetic tree results, sequences of this study were identified as R. felis Bouyer et al. Those sequences were obtained only from five of the seven cricetid species and from two of the three localities, as follows: from Street 143 and Diagonal 630, Arana neighbourhood, La Plata District: Polygenis (Polygenis) axius (Jordan and Rothschild) (n = 3) and Polygenis (Neopolygenis) atopus (Jordan and Rothschild) (n = 1); and from Balneario La Balandra, Berisso District: Polygenis (Polygenis) axius (n = 4), Polygenis (Neopolygenis) atopus (n = 1) and Craneopsylla minerva minerva (Rothschild) (n = 1). Our results confirm the presence of R. felis in fleas parasitizing cricetids in the periurban area of Gran La Plata, which could represent a risk to public health.

Dromedary camels Camelus dromedarius Linnaeus (Artiodactyla, Camelidae) are vital to the livelihoods of nomadic and pastoralist communities in the Sahara Desert. However, they are susceptible to ectoparasites, which can significantly impact their health and productivity, as well as their potential role in transmitting zoonotic diseases. This study aimed to investigate the prevalence, species composition and infestation levels of ectoparasites in dromedaries from different camel herds (CH) across northern Algeria's Sahara Desert. Additionally, we assessed the effects of CH and camel age and sex on parasite loads and infestation patterns regarding the host's affected body region. A total of 68 camels out of 135, randomly selected from four herds CH1-CH4, were surveyed for ectoparasites. Ectoparasites were counted, collected and identified in the laboratory. Pearson correlation tests were employed to analyse the relationship between parasite indices. Similarity analysis was conducted to compare ectoparasite species composition among the sampled CH. The overall infestation level of ectoparasites across the CH was 61.76% with 511 ectoparasite individuals identified. Significant regional variation in tick prevalence was observed: CH1 (88.24%), CH2 (64.71%), CH3 (58.82%) and CH4 (35.29%) (p < 0.001). The most prevalent ectoparasites were ticks, with four species identified: Hyalomma dromedarii Koch (Ixodida, Ixodidae) (45.21%), Hyalomma marginatum marginatum Koch (Ixodida, Ixodidae) (18%), Rhipicephalus sanguineus sensu lato Latreille (Ixodida, Ixodidae) (7.63%) and Ixodes ricinus Linnaeus (Ixodida, Ixodidae) (4.9%). In addition, one mite species Sarcoptes scabiei Linnaeus (Sarcoptiformes, Sarcoptidae), one flea species Ctenocephalides arabicus Jordan (Siphonaptera, Pulicidae) and one fly species Wohlfahrtia magnifica Schiner (Diptera, Sarcophagidae) were identified. Similarity analysis showed a 70% overlap in ectoparasite species composition between herds, suggesting common environmental and management-related risk factors. Overall, the abdomen exhibited the highest percentage of ectoparasites at 22.7%, followed by the neck and sternum (17.8%), and the anal and tail area (17.4%). Adults accounted for 86.1% of infestations, with notable contributions from the abdomen (17.0%) and neck/sternum (15.9%), while young camels made up only 13.9%. The high ectoparasite infestation level, particularly ticks, underscores the need for a comprehensive control plan, especially in herds managed under extensive or nomadic systems. Future research should focus on identifying risk factors and exploring ectoparasite control strategies to reduce the burden on camel health and prevent potential zoonotic disease transmission in the region.

This study reported hard tick (Ixodida: Ixodidae) infestation in sheep of Samara city, north of Baghdad, from June to December 2023. A total of 480 ticks were manually pulled out from the sheep with an ethanol-soaked tissue and preserved in plastic containers containing 70% ethyl alcohol. All samples were counted and examined individually under a light microscope to identify the genus. Preliminary microscopic examination revealed that the majority of the collected ticks were Hyalomma, with 91.4%, followed by Rhipicephalus (6.8%) and Ixodes (1.8%). Furthermore, Hyalomma was dominant across all months, with a peak relative abundance in October (100%). The peak relative abundances for Rhipicephalus (16%) and Ixodes (4.3%) occurred in July. Under further microscopic evaluation, morphological features demonstrated three species, namely, Hyalomma detritum (Koch), Hy. anatolicum (Koch) and Rhipicephalus sanguineus sensu lato (Latreille). To confirm genera and species, molecular diagnosis was performed, based on the COX1 gene, resulting in the identification of five species, namely, Hy. detritum, Hy. anatolicum, Hy. excavatum (Koch, 1844), Rh. sanguineus sensu lato and an unidentified Ixodes sp. While the Ixodes scapularis isolation unexpectedly revealed genetic resemblance to North American samples, indicating a wider geographical spread, the Hyalomma and Rhipicephalus isolates shared ancestry with other Middle Eastern strains, demonstrating regional genetic stability. These results showed the comprehensive diversity of tick species in sheep, including Hyalomma, Rhipicephalus and Ixodes, and also provided good epidemiological data to support the preventative procedures of tick-borne infections in Samarra city.

This study reports the first detection of Babesia aktasi and Anaplasma phagocytophilum in a bezoar goat (Capra aegagrus), providing insight into the presence of these pathogens in wild caprinae. The infected goat exhibited a localised ocular infection but showed no clinical signs of acute piroplasmid or Anaplasma infections. Microscopic examination of blood smears revealed low parasitemia of intra- and extraerythrocytic piroplasms and intragranulocytic morulae, consistent with chronic infection. PCR and sequence analysis confirmed that the Babesia species detected was B. aktasi, a recently described piroplasmid previously reported in domestic goats. Phylogenetic analysis placed the B. aktasi haplotype within the Babesia sensu stricto clade, closely related to sequences from domestic goats in Türkiye and an uncharacterised Babesia sp. from a red deer. The A. phagocytophilum strain detected in this study belonged to ecotype 1, which includes human pathogenic strains. These findings raise the possibility that bezoar goats may contribute to the natural maintenance of B. aktasi and A. phagocytophilum, highlighting their potential involvement in the enzootic cycles of these pathogens alongside domestic caprinae. Given that bezoar goats are the ancestors of modern domestic goats and that their habitats overlap in Anatolia, further research is needed to better understand the transmission dynamics, vector associations and zoonotic potential of these pathogens.

The blowflies (Calliphoridae) represent a significant portion of schizophoran fly diversity, comprising approximately 2000 known species. Among them, the genus Calliphora Robineau-Desvoidy is one of the largest, with over 100 species primarily distributed in the Holarctic Region and Australasia. Blowflies include several ubiquitous species and are primarily recognised for their medical and veterinary importance. In the Afrotropics, Calliphora was previously known from only two species: the native Calliphora croceipalpis Jaennicke and the introduced Calliphora vicina Robineau-Desvoidy. Two new distinctive species of Calliphora collected during recent fieldwork in Ethiopia are described using methods of integrative taxonomy. Calliphora teraramma sp. n. is characterised by peculiar male genitalia, with large cerci and a minute phallus. Calliphora mesay sp. n. is characterised by morphological and molecular traits, a close relative of the cosmopolitan C. vicina. In addition, we developed a cytochrome c oxidase subunit I (COI) barcode reference library for Palaearctic and Afrotropical Calliphora species, including 33 newly generated barcodes. Molecular species delimitation analyses using the software Automatic Barcode Gap Discovery (ABGD) and Assemble Species by Automatic Partitioning (ASAP), implemented through the recently developed integrative platform Spart Explorer, largely support morphological species concepts.

Hippobosca equina, a common ectoparasite of horses, poses a significant challenge to equine health worldwide. This study provides a molecular characterization of H. equina and examines its impact on host immune responses and oxidative stress. Genetic analysis of samples from various regions revealed notable homogeneity, indicating limited genetic variation among populations. Phylogenetic analysis demonstrated close genetic relationships among sequences from Egypt, France, Kazakhstan and Portugal, while also showing comparable but more distant identities to sequences from China, Denmark, Finland and other countries. Infested horses exhibited elevated levels of pro-inflammatory cytokines, including IL-6, TNF-α and IFN-γ, relative to uninfested control horses, indicating a strong immune response to the parasite. Additionally, there was a significant increase in oxidative stress markers, including malondialdehyde, catalase, glutathione peroxidase and nitric oxide, indicating substantial cellular damage. These findings highlight the dual impact of H. equina infestations on horse health, prompting both immune activation and oxidative stress. This study emphasizes the importance of targeted pest management strategies that consider the genetic uniformity of parasites and host physiological responses. By providing valuable insights into the complex host-parasite interactions between H. equina and equine hosts, this research enhances our understanding of equine ectoparasites and suggests potential avenues for improving horse health and welfare.

The biting midges, Culicoides peregrinus Kieffer and Culicoides oxystoma Kieffer (Diptera: Ceratopogonidae) are the most significant vector species of bluetongue virus (BTV) in the Oriental region, including India. Rearing of these vector species was cumbersome; previous researchers supplemented the rearing substrates primarily with cattle dung (the habitat), yeast and nutrient broth. Other investigations reiterated that an enriched milieu of live bacteria is required for the oviposition and developmental progression of the immatures as they failed to develop in sterile medium. Therefore, bacteria-based approaches provide novel opportunities for artificial rearing. This investigation tries to simplify and create a cleaner version of rearing based on different bacterial strains. The substrate bacterial strains were biochemically characterised, and their influence on oviposition, hatching and larval development was analysed and evaluated under laboratory conditions. We artificially reared two vector species by utilising three different strains of Bacillus cereus and one strain of Alcaligenes faecalis retrieved from the substrates. The results demonstrated that gravid females select their oviposition substrates based on stimuli derived from live microorganisms that indicate the suitability of the developmental substrate for immature development. Bacillus cereus 1B stimulated the greatest extent of egg hatching (>99%), larval survivability (>74%), pupae formation (>83%) and adult emergence (>98%) in both species. This present investigation proposes to utilise B. cereus 1B as an alternative approach to artificially rear and establish laboratory colonies of these vector species.

Bluetongue virus (BTV) is an arthropod-borne virus that is transmitted between ruminants by Culicoides (Order Diptera, Family Ceratopogonidae) midges. In September 2023, BTV serotype 3 (BTV-3/NET2023) emerged in the Netherlands, causing a devastating epidemic in sheep and cattle. The aim of this study was to determine which midge species contributed to the spread of BTV-3 and to what extent the virus is present in local midge populations. Midges were collected using Onderstepoort UV-light suction traps on BTV-affected farms in the centre of the Netherlands, from October 2023 till March 2024. Species, sex and parity of the midges were morphologically determined. Pooled female parous and gravid midges were subjected to pan-BTV and BTV-3 real-time polymerase chain reaction (PCR) testing. Pool prevalence, minimum infection rate (MIR) and infection rate (IR) were calculated. In total, 33,093 midges were morphologically identified, all being indigenous Culicoides species. Of these, 10,835 parous or gravid female midges were selected and pooled in 383 pools (mean 28.3 midges per pool, range 1-115). A total of 155 pools (40.5%) tested BTV positive, with a mean MIR/100 of 1.4 and an IR of 2.2 (95% confidence interval: 1.9-2.6). All positive pools were from batches that were collected in October 2023 (week 40 and 41). BTV-RNA was detected in the Culicoides species C. obsoletus Meigen, C. scoticus Downes and Kettle, C. chiopterus Meigen, C. dewulfi Goetghebuer and C. punctatus Meigen. The high proportion of BTV-PCR positive midge pools is indicative of a high vector competence for BTV-3/NET2023 of Dutch indigenous midges present on farms; it could potentially partly explain the rapid spread of the virus throughout the Netherlands.

The mitochondrial gene cytochrome c oxidase subunit 1 (cox1) has long been suspected to be ineffective for species identification when employed alone. Some Lucilia (=Phaenicia) cuprina Wiedemann have mtDNA haplotypes closely resembling those of Lucilia sericata Meigen (Diptera: Calliphoridae), indicating paraphyly of L. cuprina with respect to L. sericata. Therefore, we evaluated the nuclear 28S rRNA and the mitochondrial cox1 genes to distinguish between L. cuprina and L. sericata using new DNA data from Northwest Africa. The current study provides the first evidence that L. cuprina occurs in Northwest Africa. The cox1 and the 28S genes were sequenced, and phylogenetic trees were constructed using the maximum likelihood method with 1000 bootstrap replicates. Sequencing yielded around 675 bp for cox1 and 633 bp for 28S. All the sequences were accurately identified using the BLASTn and submitted to GenBank. The 28S analysis confirmed the two species' mutual monophyly. In contrast, the cox1 analysis showed that L. cuprina is divided into two distinct clades, paraphyletic with respect to L. sericata. The 28S sequences clustered together do not exhibit any geographical consistency. Despite the paraphyletic relationship between L. sericata and the two forms of L. cuprina, mtDNA appears to be useful in differentiating between these two species. However, L. cuprina subspecies, L. cuprina cuprina (Wiedemann) and L. cuprina dorsalis Robineau-Desvoidy cannot be differentiated using the 28S and cox1 genes, nor can their distinctions be assumed based on their geographic locations, especially in regions where they are found in coexistence.

Sucking lice (Anoplura) are highly specific parasites that depend extensively on their mammal hosts for survival. However, the climate to which their hosts are exposed can cause changes in their populations, independent of the protection provided by their hosts. Despite its harsh climate, arid northern Chile is home to a wide variety of rodents, particularly cricetids. This area comprises four distinct ecoregions with different sub-climates. We aimed to evaluate the spatial and seasonal variability of sucking lice (Anoplura) parasitizing rodents in northern Chile. Specifically, we analysed the association of environmental variables and host density with the louse point prevalence (P%), mean abundance (_MA) and mean infestation intensity (_MI). Rodent samples were collected during autumn and spring of 2011 and summer and winter of 2012 in 13 sites representative of the Coastal Desert (CD), Continental (Interior) Desert (ID), Andean Tropical (AT) and Pre-Andean Tropical (PAT) ecoregions. A total of 992 rodents of eight species were captured and anaesthetized, and lice were collected and identified. The P%, _MA and _MI of lice were estimated. The association of climatic variables (temperature, precipitation and relative humidity) and host density (capture success as a proxy) with louse P% and _MA was assessed using Spearman correlation and Fisher's test. Four lice species were identified based on external morphology (Hoplopleuridae: Hoplopleura aitkeni Johnson, Hoplopleura reducta Ferris, Hoplopleura sp. travassosi group; Poliplacidae: Polyplax spinulosa (Burmeister)). Hoplopleura aitkeni and H. reducta showed significant seasonal differences in P%, _MA and _MI in the AT and PAT ecoregions. In contrast, the H. sp. travassosi group showed no significant seasonal variation. Polyplax spinulosa was found exclusively on introduced rodents in the ID ecoregion, with distinct seasonal variations observed in Rattus norvegicus Berkenhout and Rattus rattus Linnaeus (Muridae). We reported 17 new host-parasite associations, and one lice species not previously described in the country. This study demonstrates that seasonal environmental variation does not equally impact all lice species, emphasizing the need for further research into the ecological and biological drivers of these dynamics.