Parasitology Research最新文献

{"title":"A new intermediate host of Echinococcus shiquicus in Qinghai-Tibet Plateau, China.","authors":"Wei-Gang Chen, Li Li, Guo-Dong Dai, Yao-Dong Wu, Nigus Abebe Shumuye, Tharheer Oluwashola Amuda, Xue-Qi Tian, Sheng-Zhi Gao, Xue-Yi Hou, Nian-Zhang Zhang, Wen-Jun Tian, Lin-Sheng Zhang, Le Li, Fu-Heng Zhang, Min-Kuan Guo, Wen-Dong Li, Zhonggecao, Zhaxilamao, Gazangzhuoma, Doukao, Tao Yang, Bao-Quan Fu, Hong Yin, Hong-Bin Yan, Wan-Zhong Jia","doi":"10.1007/s00436-025-08494-0","DOIUrl":"10.1007/s00436-025-08494-0","url":null,"abstract":"<p><p>Echinococcosis is a severe parasitic zoonosis worldwide distribution, caused by the genus Echinococcus. One of its recently identified species, Echinococcus shiquicus, is believed to be endemic to the Qinghai-Tibet plateau in China. Research has confirmed that Tibetan foxes are the definitive hosts for E. shiquicus, while plateau pikas (Ochotona curzoniae) serve as intermediate hosts. In this study, cyst containing protoscolices was first observed in the lung of plateau zokor (Eospalax baileyi) in the Tibetan Autonomous Prefecture of Gannan, Gansu Province, China. This observation was confirmed using complete sequences of the cox1 and nad1 genes. We also characterized the cysts and examined the genetic diversity of Echinococcus shiquicus collected from the Qinghai-Tibet Plateau region, which includes Gansu Province, Qinghai Province, and the Tibet Autonomous Region. Phylogenetic trees and haplotype analyses for the isolates were constructed using the maximum likelihood method in MEGA 7.0.26 and DnaSP v6 software, based on the complete cox1 (1608 bp) and nad1 (897 bp) gene sequences, as well as a concatenated dataset of cox1-nad1 (2505 bp). The cyst containing protoscolices in the lung of plateau zokor was identified as Echinococcus shiquicus. The prevalence of E. shiquicus infection in plateau pikas in Luqu and Maqu counties in Gansu province was found to be 2.38% (3/126) and 3.36% (10/298), respectively, while in plateau zokors, it was 1.61% (1/62). Haplotype analysis, incorporating sequences from previous studies, revealed the presence of 17 haplotypes, indicating significant haplotype diversity in the study areas. The neutrality indices were Tajima's D =  - 1.438 (P > 0.05) and Fu's Fs =  - 3.169 (P > 0.05). This study provides important insights into Echinococcus shiquicus and its associations with plateau zokors and plateau pikas in the Qinghai-Tibet Plateau. We identified plateau zokors as a new natural intermediate host for E. shiquicus, emphasizing the complexity of its transmission dynamics and host interactions within this unique ecosystem. The observed morphological and developmental state differences in cysts between the liver and lung suggest that presence of tissue specificity in different organ. Additionally, the analysis of genetic diversity revealed high intraspecific variability, indicating a complex population structure influenced by various ecological factors.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"66"},"PeriodicalIF":1.8,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12174222/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144317620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The complete mitogenome of Hyalomma anatolicum: novel insights into the phylogenetics of Hyalomma.","authors":"Jin Che, Yijun Chai, Wei Li, Shuaiyang Zhao, Jin Luo, Qiaoyun Ren, Qingli Niu, Guiquan Guan, Jinming Wang, Hong Yin","doi":"10.1007/s00436-025-08497-x","DOIUrl":"10.1007/s00436-025-08497-x","url":null,"abstract":"<p><p>Ticks are obligate blood-sucking ectoparasite and common vector of a wide variety of zoonotic pathogens. In this research, we sequenced and assembled the circular complete mitogenome information of Chinese isolates of Hyalomma anatolicum maintained at the Laboratory. The 14,714 bp mitogenome consists of 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes and 2 ribosomal RNA (rRNA). The nucleotide sequence of Hy. anatolicum mitogenome includes approximately A (35.05%), G (8.70%), T (41.20%) and C (11.26%), the proportion of A + T (80.04%) is substantially higher than G + C (19.96%). We compared mitogenome selection pressure of the Hy. anatolicum and found that positive selection signatures were detected in atp8, contrasting sharply with the strong purifying selection observed in cox1. Phylogenomic reconstruction using concatenated PCGs robustly placed Hy. anatolicum within a clade sister to Hy. excavatum. We further validated cox3, cytb, nad1, nad2, nad3, nad4, nad4L, nad5 and nad6 as lineage-specific markers mirroring full mitogenome topology, proposing their cost-effective use in Hyalomma systematics. The divergence time analysis suggests that Hy. anatolicum was the most recent species in Hyalomma, 1.95 Mya. As far as we know, this is the first study exploring the complete mitogenome for Hy. anatolicum. Here, we obtained the whole mitogenome sequence for the species Hy. anatolicum, which enriched the mitogenome data of ticks, provided new idea for future research on the molecular evolution, population heredity and systematics of ticks.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"67"},"PeriodicalIF":1.8,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144326542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serological detection of Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi s.l. antibodies, and Dirofilaria immitis antigen in stray dogs in Bosnia and Herzegovina.","authors":"Denis Čamo, Amir Zahirović, Dajna Preldžić, Tarik Mutevelić, Jasminka Isović, Alan Maksimović","doi":"10.1007/s00436-025-08513-0","DOIUrl":"10.1007/s00436-025-08513-0","url":null,"abstract":"<p><p>Stray dogs may be highly exposed to vector-borne pathogens (VBP), including zoonotic agents, and therefore may pose a high risk of spreading infection to other animals and humans. Our study is the first large-scale prevalence study of VBP in stray dogs in Canton Sarajevo, Bosnia and Herzegovina. During the period 2016-2018, a total of 3720 blood samples of stray dogs were screened by the SNAP 4Dx plus test for antibodies against Anaplasma spp., Ehrlichia spp., B. burgdorferi s.l., and D. immitis. The 910 dogs (910/3720, 24.46%) were seropositive for one or more CVBPs. The proportion of seropositive dogs against one, two, or three pathogens was 864 (23.23%), 43 (1.15%), and 3 (0.08%), respectively. The most prevalent canine VBP was Anaplasma spp. (21.59%), followed by B. burgdorferi s.l. (2.47%) and Ehrlichia spp. (1.13%). The lowest prevalence was recorded for D. immitis (0.5%). The number of seropositive dogs older than 1 year was 704 (704/2497, 28.19%), while the number of dogs younger than 1 year was 206 (206/1223, 16.84%). The most common dual coinfection detected was with Anaplasma spp. and B. burgdorferi s.l. (26/3720, 0.7%). The results show that stray dogs are exposed to at least one of these four CVBD pathogens. Since some of these pathogens cause zoonoses, controlling these infections is crucial for both veterinary and public health. These findings highlight the need for continuous serological monitoring of CVBD pathogens in stray dogs due to their risks to animal and human health.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"65"},"PeriodicalIF":1.8,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12162782/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nematode diversity in Mastomys rodents (Rodentia: Muridae) across a wildlife-human/domestic animal interface and molecular characterization of Trichuris species from M. natalensis.","authors":"Jesse Mukisa Mutesasira, Sonja Matthee, Charles Byaruhanga, Milana Troskie, Munyaradzi Christopher Marufu","doi":"10.1007/s00436-025-08507-y","DOIUrl":"10.1007/s00436-025-08507-y","url":null,"abstract":"<p><p>Nematodes comprise many species with diverse life histories and zoonotic potential. Globally, over 10,500 nematode species were reported in mammals, particularly rodents. In South and southern Africa, data on nematode diversity in native rodent populations remains limited. The current study aimed to address this gap by reporting nematode diversity in two Mastomys species (Mastomys coucha and M. natalensis) and conducting molecular analysis of an unidentified Trichuris species recovered from M. natalensis. A total of 68 M. natalensis and 27 M. coucha rodents were trapped across a wildlife-human/domestic animal interface in South Africa during October 2020. Gastrointestinal nematodes were recovered and morphologically identified. Morphometric assessment and Sanger sequencing of mitochondrial markers, internal transcribed spacer 1 and 2 (ITS1, ITS2) and cytochrome b (cytb) were performed on the unidentified Trichuris species. In total, 46 nematodes were identified representing two genera, Trichuris and Abbreviata, with an overall prevalence of 21.1%. Trichuris sp. dominated in M. natalensis and anthropogenically transformed habitats, while Abbreviata sp. was associated with M. coucha in the natural habitats. Morphometrics of the unidentified Trichuris sp. aligned with reported ranges for the genus, while phylogenetic analyses revealed a novel clade distinct from known Trichuris spp. The current study emphasises the importance of integrating morphometric and molecular analyses for accurate nematode identification. The potential public health threat of the novel Trichuris sp. in M. natalensis needs further investigation, given the zoonotic capability of Trichuris spp. and the proximity of rodents to humans in the study area.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"64"},"PeriodicalIF":1.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152047/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144267009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding the molecular understanding of Theileria infections in cattle and yaks from Gansu and Qinghai, China.","authors":"Yijun Chai, Jin Che, Shuaiyang Zhao, Jinming Wang, Guiquan Guan, Hong Yin","doi":"10.1007/s00436-025-08491-3","DOIUrl":"10.1007/s00436-025-08491-3","url":null,"abstract":"<p><p>Piroplasmosis is a major tick-borne disease that causes significant economic losses in livestock production across various regions. The present study aimed to provide a comprehensive assessment of the prevalence of bovine piroplasmosis in Gansu and Qinghai provinces, China, offering crucial baseline data for the development of effective control and prevention strategies. A total of 736 bovine blood samples were collected from Tianshui, Pingliang, and Lanzhou in Gansu, and Xining and Haidong in Qinghai. These samples were analyzed using PCR with universal Piroplasma primers targeting the 18S rRNA gene. The overall prevalence of bovine Piroplasma infection was found to be 25.54% (188/736). Three Theileria species were identified, including T. orientalis (14.27%, 105/736), T. annulata (10.73%, 79/736), and T. sinensis (0.54%, 4/736). No cases of Babesia or mixed infections were detected in this study. Notably, T. sinensis was reported for the first time in Pingliang, highlighting its potential expansion in the region. In conclusion, bovine piroplasmosis remains prevalent in both Gansu and Qinghai provinces, with T. orientalis being the predominant species. These findings underscore the need for strengthened surveillance and improved strategies for the prevention and control of piroplasmosis in the region.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"63"},"PeriodicalIF":1.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152086/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144267000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Porrocaecum moraveci in red kites in England and Wales, a species of conservation concern.","authors":"William S Funk, Tammy Shadbolt, Mark T Fox, Anthony W Sainsbury, Damer P Blake","doi":"10.1007/s00436-025-08512-1","DOIUrl":"10.1007/s00436-025-08512-1","url":null,"abstract":"<p><p>The population of free-living red kites (Milvus milvus [Linnaeus 1758]) in England and Wales has increased since 1989 as a consequence of species reintroduction. The red kite, however, remains of conservation concern, with populations in Europe considered to be in decline. Plans to translocate birds from England to Spain have been initiated, prompting consideration of the disease risks associated with the translocation of parasites which may be present within the source population. This study utilized published morphological markers and molecular polymerase chain reaction techniques to identify archived adult helminth parasites extracted from the gastrointestinal tract of red kites found dead and examined post-mortem in England and Wales between 2014 and 2021. Helminths of the genus Porrocaecum (Railliet and Harry 1912) were identified in 22 out of the 23 helminth-infected red kites from a wide geographical distribution, suggesting that this parasite is common in the red kite population in England and Wales. Molecular characterization using internal transcribed spacer 2 (ITS-2) and 28S rDNA sequences identified Porrocaecum moraveci (Gu et al. 2023), the first report of this recently described species in the UK. Ascaridia (Dujardi 1845) sp., Capillaria (Zeder 1800) sp., and Syngamus trachea (Montagu 1811) ova were also detected during the post-mortem examinations (PMEs) and are known to be present within European red kite populations, suggesting that these parasites do not represent a novel disease risk to the destination population in Spain. Previous reports of Porrocaecum angusticolle (Molin, 1860) in British and other European red kite populations should now be revisited to confirm identity and assess the risk of parasite translocation.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"61"},"PeriodicalIF":1.8,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152035/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling hidden battles: Genetic insights into parasite diversity and competition in mottled triplefin (Forsterygion capito).","authors":"Sila Viriyautsahakul, Robert Poulin, Sheri L Johnson, Jerusha Bennett","doi":"10.1007/s00436-025-08495-z","DOIUrl":"10.1007/s00436-025-08495-z","url":null,"abstract":"<p><p>Parasites play an important role in ecosystems, often exhibiting complex life cycles that involve two to four host species and transmission through trophic interactions. By tracking parasite life cycles, predator-prey links can be identified, offering valuable insights into food webs. In this study, we examined the helminth community of the mottled triplefin (Forsterygion capito), one of the most common intertidal fish species in New Zealand, using molecular techniques. We identified 14 parasite species, including one new to science and three new host records. These findings established new predator-prey links in the previously known local food web. We also provide evidence of parasite competition, focusing on the trematode Cardiocephaloides ovicorpus, the most prevalent and abundant parasite found in the brain case of F. capito. As the intensity of C. ovicorpus metacercariae increased, their individual size decreased, suggesting intraspecific competition for resources within the limited space of the brain case. Additionally, C. ovicorpus may indirectly outcompete other parasite species using F. capito by inducing host behavioural manipulation to enhance its transmission to avian hosts given its encystment site within the brain case of the fish. Overall, our findings emphasise the importance of obtaining information about parasites in order to improve our understanding of species interactions within ecosystems.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"62"},"PeriodicalIF":1.8,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avian haemosporidian parasite prevalence and diversity in two populations of the American kestrel (Falco sparverius).","authors":"Laura Kwasnoski, Jordan Brown, Jessica Taylor, Jesse L Watson, Dave Oleyar, Vincenzo A Ellis","doi":"10.1007/s00436-025-08509-w","DOIUrl":"10.1007/s00436-025-08509-w","url":null,"abstract":"<p><p>Parasite communities vary among host species and across space. However, little is known about differences in parasite communities between geographically and genetically distinct populations of the same host species. American kestrels (Falco sparverius) are small falcons with regionally distinct genetic populations across North America. We sampled kestrels from Delaware and Utah for avian haemosporidian parasites (genera: Haemoproteus, Plasmodium, and Leucocytozoon) and used molecular barcoding of the parasite cytochrome b gene (cyt b) to quantify parasite genetic lineage diversity. We identified four lineages of Haemoproteus parasites and one Leucocytozoon lineage infecting kestrels. A comparison with previous studies suggests that most of these lineages are largely restricted to kestrels. We found similar infection prevalence and lineage composition between the sites. All kestrels sampled in Utah were adults (i.e., sampled after hatch year), but in Delaware, we found adult birds had a higher infection prevalence than juveniles (i.e., hatch-year birds). Despite harboring largely the same parasite lineages, kestrels are unlikely to disperse between Utah and Delaware. The similarity in parasite lineages in the two kestrel populations could be due to a number of factors including broadly distributed vector species (of which little is known), movement of alternative and undetected host species, or transmission during migration or on overwintering grounds. Alternatively, the cyt b gene might not capture recent genetic differentiation among the parasites. Future studies should explore these various possibilities to understand the mechanisms underpinning parasite distributions across genetically structured host populations.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"60"},"PeriodicalIF":1.8,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12149002/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144249146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro molting of Dirofilaria immitis third-stage larvae derived from microfilariae collected from doxycycline-treated dogs.","authors":"Yi Chu, Elyssa Campbell, Michael Dzimianski, Christopher C Evans, Cassan Pulaski, Kaori Sakamoto, Andrew R Moorhead","doi":"10.1007/s00436-025-08506-z","DOIUrl":"10.1007/s00436-025-08506-z","url":null,"abstract":"<p><p>Dirofilaria immitis, also known as canine heartworm, contains an endosymbiont, Wolbachia, in all life stages. The antibiotic, doxycycline, has been incorporated into heartworm treatment protocols to eliminate Wolbachia. Previous studies indicate that subsequent infection cannot be established using viable third-stage larvae (L3) developed from doxycycline-treated microfilariae (mf). The stages in which the development of larvae is impacted by doxycycline remain unknown. We examined the impact of doxycycline on the third-stage to fourth-stage larval molt, as it is the first molt of D. immitis after it invades the vertebrate host. Microfilaremic blood was collected weekly from D. immitis-infected dogs with or without doxycycline treatment at 10 mg/kg as recommended by the American Heartworm Society. Blood was collected weekly until the end of doxycycline treatment. The blood was used for L3 production and mf isolation. Wolbachia levels in mf and L3 were measured using real-time quantitative PCR. L3 were cultured in vitro for 9 days to assess whether molting occurred. The Fisher's exact test and Bonferroni correction were used for statistical analysis. The molting of L3 from the doxycycline-treated groups did not show a significant difference compared to the L3 from the control group at weeks 0, 1, 2, 3, and 4. The Wolbachia levels in mf and L3 decreased starting from 7 days post-treatment and remained less than five percent of controls throughout the treatment. Doxycycline treatment can eliminate Wolbachia in both mf and subsequently developed L3. The molts of the mf to L3 in the mosquito and the L3 to L4 molt in vitro do not appear to be impacted by the reduction or elimination of Wolbachia.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"59"},"PeriodicalIF":1.8,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12133980/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144209118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmentally derived Balamuthia mandrillaris contains endosymbiotic bacteria.","authors":"Kanako Yamanouchi, Takamasa Nagai, Takakiyo Tsujiguchi, Mitsuru Chiba, Miyuki Fujioka, Chowdhury Rafiqul Ahsan, Tomoh Matsumiya","doi":"10.1007/s00436-025-08505-0","DOIUrl":"10.1007/s00436-025-08505-0","url":null,"abstract":"<p><p>Balamuthia mandrillaris is an environmentally derived, free-living amoeba that causes fatal meningoencephalitis. We previously isolated B. mandrillaris from soil in the Aomori Prefecture and attempted to culture the cell-free amoeba using liquid medium; however, this was difficult to achieve because of contamination of the medium with endogenous bacteria. The aim of this study was to determine the presence of endogenous bacteria in environmentally derived B. mandrillaris and identify bacteria. Two new environmentally derived B. mandrillaris strains were isolated from soil samples collected throughout Japan. Environmentally derived B. mandrillaris was cultured under nutrient-free conditions for 60 days, and the induced cysts contained large amounts of viable bacteria. The sequence of the endophytic bacteria revealed that the genus Chitinophaga was common between the two strains of B. mandrillaris. The opportunistic pathogens Inquilinus and Brevundimonas were also detected. All of these bacteria were pigment-producing species. Bacterial pigment production helps protect organisms from extremes of heat and cold, increases the virulence of pathogenic strains, and protects organisms from protein and DNA damage caused by UV light and ionizing radiation. This suggests that B. mandrillaris preserving bacteria in a viable state for a long time under severe conditions with no nutrition may be the ability of the bacteria to produce pigments.</p>","PeriodicalId":19968,"journal":{"name":"Parasitology Research","volume":"124 6","pages":"57"},"PeriodicalIF":1.8,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12130064/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144199854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}