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Symbiosis between insects and bacteria has been established countless times. While it is well known that the symbionts originated from a variety of different bacterial taxa, it is usually difficult to determine their environmental source and a route of their acquisition by the host. In this study, we address this question using a model of Neisseriaceae symbionts in rodent lice. These bacteria established their symbiosis independently with different louse taxa (Polyplax, Hoplopleura, Neohaematopinus), most likely from the same environmental source. We first applied amplicon analysis to screen for candidate source bacterium in the louse environment. Since lice are permanent ectoparasites, often specific to the particular host, we screened various microbiomes associated with three rodent species (Microtus arvalis, Clethrionomys glareolus, and Apodemus flavicollis). The analyzed samples included fur, skin, spleen, and other ectoparasites sampled from these rodents. The fur microbiome data revealed a Neisseriaceae bacterium, closely related to the known louse symbionts. The draft genomes of the environmental Neisseriaceae, assembled from all three rodent hosts, converged to a remarkably small size of approximately 1.4 Mbp, being even smaller than the genomes of the related symbionts. Our results suggest that the rodent fur microbiome can serve as a source for independent establishment of bacterial symbiosis in associated louse species. We further propose a hypothetical scenario of the genome evolution during the transition of a free-living bacterium to the member of the rodent fur-associated microbiome and subsequently to the facultative and obligate louse symbionts., (© 2024. The Author(s).)

Background: Bartonella quintana is a body louse-borne bacterium causing bacteremia and infective endocarditis. We aimed to describe B. quintana detection among arthropods and their hosts., Methods: We searched databases in PubMed Central/MEDLINE, Scopus, Embase, and Web of Science from January 1, 1915 (the year of B. quintana discovery) to January 1, 2024, to identify publications containing specific search terms relating to B. quintana detection among arthropods. Descriptive statistics and meta-analysis of pooled prevalence using random-effects models were performed for all arthropods and body and head lice., Results: Of 1265 records, 62 articles were included, describing 8839 body lice, 4962 head lice, and 1692 other arthropods, such as different species of fleas, bedbugs, mites, and ticks. Arthropods were collected from 37 countries, of which 28 had arthropods with B. quintana DNA. Among articles that reported B. quintana detection among individual arthropods, 1445 of 14,088 (0.1026, 95% CI [0.0976; 0.1077]) arthropods tested positive for B. quintana DNA, generating a random-effects model global prevalence of 0.0666 (95% CI [0.0426; 0.1026]). Fifty-six studies tested 8839 body lice, of which 1679 had B. quintana DNA (0.1899, 95% CI [0.1818; 0.1983]), generating a random-effects model pooled prevalence of 0.2312 (95% CI [0.1784; 0.2843]). Forty-two studies tested 4962 head lice, of which 390 head lice from 20 studies originating from 11 different countries had B. quintana DNA (0.0786, 95% CI [0.0713; 0.0864]). Eight studies detected B. quintana DNA exclusively on head lice. Five studies reported greater B. quintana detection on head lice than body lice; all originated from low-resource environments., Conclusions: Bartonella quintana is a vector-borne bacterium with a global distribution, disproportionately affecting marginalized populations. Bartonella quintana DNA has been detected in many different arthropod species, though not all of these arthropods meet criteria to be considered vectors for B. quintana transmission. Body lice have long been known to transmit B. quintana. A limited number of studies suggest that head lice may also act as possible vectors for B. quintana in specific low-resource contexts., (© 2024. The Author(s).)

Human lice have always been a major public health concern due to their vector capacity for louse-borne infectious diseases, like trench fever, louse-borne relapsing fever, and epidemic fever, which are caused by Bartonella quintana, Borrelia recurrentis, and Rickettsia prowazekii, respectively. Those diseases are currently re-emerging in the regions of poor hygiene, social poverty, or wars with life-threatening consequences. These louse-borne diseases have also caused outbreaks among populations in jails and refugee camps. In addition, antibodies and DNAs to those pathogens have been steadily detected in homeless populations. Importantly, more bacterial pathogens have been detected in human lice, and some have been transmitted by human lice in laboratories. Here, we provide a comprehensive review and update on louse-borne infectious diseases/bacterial pathogens., Competing Interests: Declaration of competing interest We declare no competing interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Wild rodents are considered as potential carriers of several zoonotic vector-borne bacteria but their epidemiology is poorly understood in Tunisia. A total of 305 biological samples (100 spleens, 100 livers, 100 kidneys, and 5 pooled ectoparasites (Xenopsylla cheopis, Laelaps echidninus, Ornithonyssus sp., Hoplopleura sp. and eggs of the rat fleas)) were collected from 100 wild rodents from three Tunisian governorates. Molecular screening was performed to reveal infections with main vector-borne bacteria. Captured rodents belonged to three rodent genera and species including Rattus rattus (n = 51, 51%), Meriones shawi (n = 24, 24%) and Mus musculus (n = 25, 25%). Examined rodents were found to be heavily infested by the rat flea X. cheopis (n = 32, 47%) and the rat mite L. echidninus (n = 22, 32.3%). However, the rat mite Ornithonyssus sp. (n = 13, 19.1%) and the rat lice Hoplopleura sp. (n = 1, 1.5%) were rarely identified. Based on 16S rRNA and msp4 genes, infection with Anaplasmataceae bacteria was detected in six specimens of R. rattus and one M. shawi. Pathogenic A. phagocytophilum (n = 1), A. phagocytophilum-like 1 (Anaplasma sp. Japan) (n = 1), and A. ovis (n = 5) were identified. On the basis of ompB, ompA and gltA genes, infection with Rickettsia spp. was identified in three specimens of R. rattus and one of M. shawi. Five Rickettsia species of the spotted fever group, corresponding to R. monacensis, R. helvetica, R. massiliae, R. africae, and R. aeschlimannii, were detected in mixed infections. Bartonella henselae DNA was also found in two R. rattus, based on rpoB partial sequences. All revealed Anaplasma, Rickettsia and Bartonella bacteria were detected in spleen samples. Ehrlichia, Coxiella and Borrelia spp. were not identified in any of the tested samples. In Tunisia, this is the first report indicating infections with Anaplasma, Rickettsia and Bartonella spp. in wild rodents, particularly present alongside domestic livestock and human. This represents a serious risk of potential bacterial transmission. Thus, controlling rodent population in animal herds, residential areas and sensitizing local people to this risk seem absolutely necessary., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Bacterial infection is a highly complex biological process involving a dynamic interaction between the invading microorganism and the host. Specifically, intracellular pathogens seize control over the host cellular processes including membrane dynamics, actin cytoskeleton, phosphoinositide metabolism, intracellular trafficking and immune defense mechanisms to promote their host colonization. To accomplish such challenging tasks, virulent bacteria deploy unique species-specific secreted effectors to evade and/or subvert cellular defense surveillance mechanisms to establish a replication niche. However, despite superficially similar infection strategies, diverse Rickettsia species utilize different effector repertoires to promote host colonization. This review will discuss our current understandings on how different Rickettsia species deploy their effector arsenal to manipulate host cellular processes to promote their intracytosolic life within the mammalian host., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS.)

The rodent-murine ectoparasite-human model of plague transmission does not correspond with historical details around plague pandemics in Europe. New analysis of ancient genomes reveal that Yersinia pestis was unable to be transmitted by rat fleas until around 4000 Before Present, which challenges the rodent-murine ectoparasite-human model of plague transmission and historical details around plague pandemics in Europe. In this Review, we summarise data regarding Y pestis transmission by human lice in the context of genomic evolution and co-transmission of other major epidemic deadly pathogens throughout human history, with the aim of broadening our view of plague transmission. Experimental models support the efficiency of human lice as plague vectors through infected faeces, which suggest that Y pestis could be a louse-borne disease, similar to Borrelia recurrentis, Rickettsia prowazekii, and Bartonella quintana. Studies have shown that louse-borne outbreaks often involve multiple pathogens, and several cases of co-transmission of Y pestis and B quintana have been reported. Furthermore, an exclusive louse-borne bacterium, namely B recurrentis, was found to be circulating in northern Europe during the second plague pandemic (14th-18th century). Current data make it possible to attribute large historical pandemics to multiple bacteria, and suggests that human lice probably played a preponderant role in the interhuman transmission of plague and pathogen co-transmission during previous large epidemics, including plague pandemics., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Arthropod-borne diseases are widespread worldwide and are a complex interaction between animals, humans and ectoparasites. The understanding of the diversity and epidemiology of organisms transmitted by arthropod vectors, and the role of hosts and vectors in transmission of infections remain limited in Lao PDR. What knowledge does exist is primarily focused on more rural regions of the country. This study screened ectoparasites from domestic dogs in Vientiane city for the presence of bacterial pathogens of zoonotic importance. A total of 3,511 arthropod vectors were collected from 112 dogs. Vectors collected were Rhipicephalus sanguineus ticks, Ctenocephalides felis felis and Ctenocephalides felis orientis fleas and Heterodoxus spiniger lice. A sub-sample of vectors from each dog was analysed by PCR to identify the potential bacteria. From 129 vector pools, Rickettsia spp. was detected in 6.7% (7/105) pools of ticks, 86.4% (19/22) pools of fleas and both pools of lice. Sequencing analysis confirmed Rickettsia felis in 13 flea pools and one louse pool and Rickettsia asembonensis in six flea pools. Anaplasmataceae was identified in 14.3% (15/105) tick pools and 100% (22/22) flea pools. Sequencing revealed the presence of Anaplasma platys in ticks and Wolbachia pipientis in fleas. Leptospira spp. was detected in one tick and one louse pool, and Brucella spp. was detected in 12.4% (13/105) tick pools. All samples were negative for Bartonella spp., Coxiella burnetii and Borrelia burgdorferi. This is the first study providing evidence of R. asembonensis in fleas in Laos. Results from this study show arthropods are potential vectors to transmit zoonotic infection in Vientiane city, suggesting humans are at risk of zoonotic infections in the city., (© 2020 The Authors. Zoonoses and Public Health published by Blackwell Verlag GmbH.)

Ectoparasites and livestock-associated insects are a major concern throughout the world because of their economic and welfare impacts. Effective control is challenging and relies mainly on the use of chemical insecticides and acaricides. Wolbachia, an arthropod and nematode-infecting, maternally-transmitted endosymbiont is currently of widespread interest for use in novel strategies for the control of a range of arthropod-vectored human diseases and plant pests but to date has received only limited consideration for use in the control of diseases of veterinary concern. Here, we review the currently available information on Wolbachia in veterinary ectoparasites and disease vectors, consider the feasibility for use of Wolbachia in the control of livestock pests and diseases and highlight critical issues which need further investigation., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

We sought to evidence the presence of emerging bacterial pathogens in clothes lice collected from sheltered homeless individuals from Marseille, France. During the 2013-2018 period, a total of 507 lice were collected from 37 individuals and were processed for molecular analysis. We reported a low prevalence of Bartonella quintana DNA carriage (1.2%). No louse tested positive for Rickettsia sp., Rickettsia prowazekii , Borrelia sp., Anaplasma sp., Yersinia Pestis , or Coxiella burnetii . A comparison with studies conducted before 2013 showed a 17.5-fold reduction in the rate of B. quintana DNA positivity. By contrast, a high prevalence of Acinetobacter species DNA carriage (40.8%), mostly A. baumannii (32.9%), was observed, tending to increase over time. In addition, we detected Acinetobacter ursingii DNA in clothes lice for the first time. Genotypic characterization and antimicrobial susceptibility testing of A. baumannii isolates from clothes lice are needed to assess whether these A. baumannii strains present in lice are similar to those responsible for human infections and harbor mechanisms of resistance against antibiotics.

Worldwide, Bartonella species are known to infect a wide range of mammalian and arthropod hosts, including humans. The current study aimed to investigate the prevalence of Bartonella spp. in synanthropic mammals captured in peri-urban areas from Central-Western and Southern Brazil and their ectoparasites. For this aim, 160 mammals belonging to four species, and 218 associated arthropods were sampled. DNA was extracted and subjected to different Bartonella screening assays. Additionally, blood samples from 48 small rodents were submitted to liquid BAPGM culture followed by qPCR assay and solid culture. Two out of 55 Rattus captured in Santa Catarina state were PCR-positive for Bartonella when targeting the nuoG, 16S, and ITS loci. Sequences showed high homology with Bartonella coopersplainsensis. Conversely, all 48 small rodents, 14 capybaras and 43 opossum DNA samples from animals trapped in Mato Grosso do Sul were Bartonella negative in the HRM real time PCR assays targeting the ITS locus and gltA gene. Additionally, all mammal-associated ectoparasites showed negativity results based on HRM real time PCR assays. The present study showed, for the first time, the occurrence of B. coopersplainsensis in Brazil, shedding some light on the distribution of rats-related Bartonella in South America. In addition, the majority of rodents and marsupials were negative for Bartonella spp. Since B. coopersplainsensis reservoirs - Rattus spp. - are widely dispersed around the globe, their zoonotic potential should be further investigated., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Bacterial arthropod-borne pathogens can often cause fever in Africa, but rural laboratories in these settings are usually too basic to provide a precise picture of their epidemiological impact. Our aim was to determine the prevalence of bacterial pathogens in fleas and lice in a rural area of southeast Ethiopia. Between July and November 2013, we extracted DNA from 91 fleas ( Ctenocephalides felis [ n  = 50; 54.9%], Pulex irritans [ n  = 37; 40.1%], and C. canis [ n  = 4; 4.4%] and 30 lice ( Pediculus humanus capitis [ n  = 16; 53.3%] and Pediculus humanus humanus [ n  = 14; 46.7%]), using two quantitative PCR (qPCR) analyses to look for bacteria from the genera: Anaplasma , Bartonella , Borrelia , Coxiella , Ehrlichia , Francisella , and Rickettsia . Of the 91 fleas analyzed, pathogens were present in 79 (86.8%), including Rickettsia felis ( n  = 41; 45%), Anaplasma platys ( n  = 40; 44.0%), Rickettsia monacensis ( n  = 2; 2.2%), Ehrlichia muris- like agent ( n  = 1; 1.1%), and Bartonella clarridgeiae ( n  = 1; 1.1%). P. irritans was the flea species most frequently infected with A. platys (67.7%), followed by C. felis (30.7%) ( p  < 0.001). Of the 30 lice identified, pathogens were present in 7 (23.3%): Bartonella quintana ( n  = 4; 16.7%), E. muris ( n  = 2, 6.7%), and Borrelia recurrentis ( n  = 1, 3.3%). Thus, in this rural area of Africa, fleas and lice can transmit parasitic pathogens to humans, causing febrile symptoms.

Human infestation with head lice, Pediculus humanus capitis De Geer, is the most prevalent ectoparasitic condition in the modern world. The purpose of this study was to test human head lice from Madagascar for infection with 2 louse-borne bacteria, Bartonella quintana and Acinetobacter spp. including Acinetobacter baumannii , to assess the potential risk of exposure to these pathogens in rural populations experiencing head-louse pediculosis. A second aim was to determine the occurrence of a biomarker for permethrin resistance in head lice from 6 isolated human communities in Madagascar. Deoxyribonucleic acid (DNA) of B. quintana was detected using species-specific Fab3 gene TaqMan in 12.6% of lice from 4 villages. DNA of Acinetobacter spp. was detected using rpo B TaqMan in 42.1% of lice collected from all locations; 58.3% of rpo B-positive lice had the bla OXA51 -like enzyme gene specific for A. baumannii . The kdr -resistant allele was detected in 70% of lice tested and was found in lice from each location. These results provide the first information regarding these combined characteristics of head-louse infestations in Madagascar. This approach can be applied to larger and broader surveys of lice from pediculosis capitis occurring in other geographic locations.

Arthropods are small invertebrate animals, among which some species are hematophagous. It is during their blood meal that they can transmit pathogenic microorganisms that they may be harboring to the vertebrate host that they parasitize, which in turn will potentially develop a vector-borne disease. The transmission may occur directly through their bite, but also through contaminated feces. Zoonotic diseases, diseases that can naturally be transmitted between humans and animals, are a considerable part of emerging diseases worldwide, and a major part of them are vector-borne. Research and public attention has long been focused on malaria and mosquito-borne arboviruses, and bacterial vector-borne diseases remains today a neglected field of medical entomology. Despite the emphasis on Lyme disease in recent decades, and despite the major outbreaks caused by bacteria in the last few centuries, this field has in fact been poorly explored and is therefore relatively poorly known, other than the most famous examples such as the plague and epidemic typhus outbreaks. Here we propose to review the state of knowledge of bacterial agents transmitted by arthropod vectors.

The objective of this study was to screen and identify rickettsial organisms in ectoparasites collected from dogs in a shelter in Gomez Palacio, Durango, Mexico. One hundred dogs were inspected for ectoparasites. All the dogs were parasitized with Rhipicephalus sanguineus ticks, three with Heterodoxus spiniger lice and one with Ctenocephalides felis fleas. DNA was extracted from the ectoparasites found on each dog, and PCR with the primers for the Anaplasmataceae 16S rRNA and citrate synthase gltA genes were performed. Eight DNA samples obtained from ticks, three from lice and one from fleas were positive to 16S rRNA. Only one sample from C. felis and one from H. spiniger were positive to gltA. Sequence analysis of amplified products from C. felis showed identity to Rickettsia felis, Wolbachia pipientis, and Wolbachia spp., while a sequence from H. spiniger showed identity to Wolbachia spp. Herein we report the molecular detection of R. felis, W. pipientis, and Wolbachia spp. in C. felis and H. spiniger in northern Mexico. These results contribute to the knowledge of the microorganisms present in ectoparasites from dogs in Mexico., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Vector-borne infections are persistent public health threats worldwide. In recent years, a number of mosquito-borne viruses have emerged or re-emerged to cause major disease outbreaks. Other vector-borne pathogens, however, remain understudied and much neglected especially in the developing regions of the world including Southeast Asia. In this study, the brown dog tick Rhipicephalus sanguineus sensu lato, cat louse Felicola subrostratus, and cat fleas Ctenocephalides felis and Ctenocephalides orientis collected from free-ranging cats and dogs in Malaysia were molecularly screened for the presence of Bartonella and Rickettsia bacteria, and Dipylidium tapeworm. Our results showed the presence of Bartonella clarridgeiea, Bartonella henselae (lineage Marseille and lineage Houston-1), and Rickettsia sp. in C. felis. We also detected Rickettsia asembonensis in C. orientis and R. sanguineus s.l. Additionally, this study provides the first documentation on a potentially new species of Dipylidium infecting F. subrostratus and C. felis. Our results highlight the role of ectoparasites from free-ranging animals including cats and dogs, in harboring multiple transmissible pathogens., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Rickettsioses are re-emerging vector-borne zoonoses with a global distribution. Recently, Rickettsia sp. strain Atlantic rainforest has been associated with new human spotted-fever (SF) cases in Brazil, featuring particular clinical signs: eschar formation and lymphadenopathy. These cases have been associated with the tick species, Amblyomma ovale From 2010 until 2015, the Brazilian Health Department confirmed 11 human SF cases in the Maciço de Baturité region, Ceará, Brazil. The present study reports the circulation of Rickettsia spp. in vectors from this entirely new endemic area for SF. A total of 1,727 ectoparasites were collected in this area from the environment, humans, and wild and domestic animals. Samples (n = 887) were screened by polymerase chain reaction (PCR), targeting the gltA and ompA rickettsial genes. Sequencing and phylogenetic analyses of gltA gene amplicons were carried out for 13 samples positive for both screening PCRs. Fragments of gltA and ompA from three samples were cloned, sequenced, and analyzed further. A. ovale and Rhipicephalus sanguineus specimens, collected from dogs, were found to be infected with Rickettsia sp. str. Atlantic rainforest, suggesting the importance of dogs in the epidemic cycle. Candidatus Rickettsia andeanae, Rickettsia felis, and Rickettsia bellii were also found infecting ticks and fleas in five municipalities, demonstrating the broad diversity of rickettsiae in circulation in the studied area. This study reports, for the first time, evidence of infection with Rickettsia sp. strain Atlantic rainforest in A. ovale and R. sanguineus in Ceará, and Ca. R. andeanae in an Atlantic rainforest environment of Brazil., (© The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

In August 2012, laboratory tests confirmed a mixed outbreak of epidemic typhus fever and trench fever in a male youth rehabilitation center in western Rwanda. Seventy-six suspected cases and 118 controls were enrolled into an unmatched case-control study to identify risk factors for symptomatic illness during the outbreak. A suspected case was fever or history of fever, from April 2012, in a resident of the rehabilitation center. In total, 199 suspected cases from a population of 1,910 male youth (attack rate = 10.4%) with seven deaths (case fatality rate = 3.5%) were reported. After multivariate analysis, history of seeing lice in clothing (adjusted odds ratio [aOR] = 2.6, 95% confidence interval [CI] = 1.1-5.8), delayed (≥ 2 days) washing of clothing (aOR = 4.0, 95% CI = 1.6-9.6), and delayed (≥ 1 month) washing of beddings (aOR = 4.6, 95% CI = 2.0-11) were associated with illness, whereas having stayed in the rehabilitation camp for ≥ 6 months was protective (aOR = 0.20, 95% CI = 0.10-0.40). Stronger surveillance and improvements in hygiene could prevent future outbreaks., (© The American Society of Tropical Medicine and Hygiene.)

We have been involved in the field of paleomicrobiology since 1998, when we used dental pulp to identify Yersinia pestis as the causative agent of the great plague of Marseille (1720). We recently designed a specific technique, "suicide PCR," that can prevent contamination. A controversy arose between two teams, with one claiming that DNA must be altered to amplify it and the other group claiming that demographic data did not support the role of Y. pestis in the Black Death (i.e., the great plague of the Middle Ages). These controversies led us to evaluate other epidemiological models and to propose the body louse as the vector of this pandemic. This proposal was substantiated by experimental models, the recovery of Y. pestis from lice in the Congo, and the identification of epidemics involving both Y. pestis and Bartonella quintana (the agent of trench fever, transmitted by the body louse) in ancient corpses from mass graves. Paleomicrobiology has led to a re-evaluation of plague pandemics.

Background: Multiple important human and livestock pathogens employ ticks as their primary host vectors. It is not currently known whether this means of infecting a host arose once or many times during evolution., Results: In order to address this question, we conducted a comparative genomics analysis on a set of bacterial pathogens from seven genera - Borrelia, Rickettsia, Anaplasma, Ehrlichia, Francisella, Coxiella, and Bartonella, including species from three different host vectors - ticks, lice, and fleas. The final set of 102 genomes used in the study encoded a total of 120,046 protein sequences. We found that no genes or metabolic pathways were present in all tick-borne bacteria. However, we found some genes and pathways were present in subsets of tick-transmitted organisms while absent from bacteria transmitted by lice or fleas., Conclusion: Our analysis suggests that the ability of pathogens to be transmitted by ticks arose multiple times over the course of evolution. To our knowledge, this is the most comprehensive study of tick transmissibility to date.

European badgers and raccoon dogs and their associated ticks and lice were assayed for the presence of Lyme borreliosis and relapsing fever-group spirochete DNA in western Poland. Analyses of blood, ear-biopsy and liver samples revealed that 25% of 28 raccoon dogs and 12% of 34 badgers were PCR positive for borreliae. Borrelia garinii was the dominant species in raccoon dogs (62.5%), followed by B. afzelii (25%) and B. valaisiana (12.5%). PCR-positive badgers were infected only with B. afzelii. A total of 351 attached ticks was recovered from 23 (82%) of the raccoon dogs and 13 (38%) of the badgers. Using a nested PCR targeting the ITS2 fragments of Ixodes DNA, four Ixodes species were identified: I. ricinus, I. canisuga, I. hexagonus, and one provisionally named I. cf. kaiseri. Ixodes canisuga and I. ricinus prevailed on both host species. The highest infection prevalence was detected in I. ricinus, followed by I. canisuga and I. cf. kaiseri. Borrelia garinii and B. afzelii accounted for 61.6% and 30.1% of the infections detected in all PCR-positive ticks, respectively. Four other Borrelia species (B. burgdorferi sensu stricto, B. valaisiana, B. lusitaniae and B. miyamotoi) were detected only in I. ricinus from raccoon dogs. Moreover, Borrelia DNA, mostly B. garinii, was detected in 57 (81.4%) of 70 Trichodectes melis lice derived from 12 badgers. The detection of B. afzelii in one-half of PCR-positive biopsies reconfirms previous associations of this species with mammalian hosts, whereas the high prevalence of B. garinii in feeding lice and I. ricinus ticks (including larvae) demonstrates that both carnivores serve as hosts for B. garinii. The lack of B. garinii DNA in the tissues of badgers versus its prevalence in raccoon-dog biopsies, however, incriminates only the latter carnivore as a potential reservoir host., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

An extracellular 1,3-1,4-β-glucanase-producing strain S2 was isolated from booklice and identified as Bacillus methylotrophicus. Furthermore, a homogeneous extracellular 1,3-1,4-β-glucanase GCS2 was purified by ammonium sulfate precipitation and cation-exchange chromatography. The gene for the 1,3-1,4-β-glucanase was cloned, and the nucleotide sequence was determined. Characterization of the purified enzyme revealed the molecular mass of 26 kDa and the optimum activity at pH 7.5, 55°C. The purified enzyme can highly hydrolyze carboxymethylcellulose including oat gum, barley β-glucan, CMC and lichenan, while low activity on avicel, cellobiose, filter paper, p-nitrophenyl β-d-cellobioside, and p-nitrophenyl β-d-glucoside, but no activity against microcrystalline cellulose or salicin. The enzyme was stable at wide range of pHs 5-10 and still maintained above 60% activity at 70°C. The enzyme activity was stimulated by Trixon X-100. The property of the enzyme GCS2 makes this enzyme a broad prospect in brewing and commercial detergent industry. To our knowledge, this is the first report of a 1,3-1,4-β-glucanase from microbes associated with booklice., (Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Our study highlights the surveillance of Bartonella species among rodents and their associated ectoparasites (ticks, fleas, lice, and mites) in several regions across Thailand. A total of 619 rodents and 554 pooled ectoparasites (287 mite pools, 62 flea pools, 35 louse pools, and 170 tick pools) were collected from 8 provinces within 4 regions of Thailand. Bandicota indica (279), Rattus rattus (163), and R. exulans (96) were the most prevalent species of rats collected in this study. Real-time PCR assay targeting Bartonella-specific ssrA gene was used for screening and each positive sample was confirmed by PCR using nuoG gene. The prevalence of Bartonella DNA in rodent (around 17%) was recorded in all regions. The highest prevalence of Bartonella species was found in B. savilei and R. rattus with the rate of 35.7% (5/14) and 32.5% (53/163), respectively. High prevalence of Bartonella-positive rodent was also found in B. indica (15.1%, 42/279), and R. norvegicus (12.5%, 5/40). In contrast, the prevalence of Bartonella species in ectoparasites collected from the rats varied significantly according to types of ectoparasites. A high prevalence of Bartonella DNA was found in louse pools (Polyplax spp. and Hoplopleura spp., 57.1%) and flea pools (Xenopsylla cheopis, 25.8%), while a low prevalence was found in pools of mites (Leptotrombidium spp. and Ascoschoengastia spp., 1.7%) and ticks (Haemaphysalis spp., 3.5%). Prevalence of Bartonella DNA in ectoparasites collected from Bartonella-positive rodents (19.4%) was significantly higher comparing to ectoparasites from Bartonella-negative rodents (8.7%). The phylogenetic analysis of 41 gltA sequences of 16 Bartonella isolates from rodent blood and 25 Bartonella-positive ectoparasites revealed a wide range of diversity among Bartonella species with a majority of sequences (61.0%) belonging to Bartonella elizabethae complex (11 rodents, 1 mite pool, and 5 louse pools), while the remaining sequences were identical to B. phoceensis (17.1%, 1 mite pool, 5 louse pools, and 1 tick pool), B. coopersplainensis (19.5%, 5 rodents, 1 louse pool, and 2 tick pools), and one previously unidentified Bartonella species (2.4%, 1 louse pool).

Symbiosis between insects and bacteria result in a variety of arrangements, genomic modifications, and metabolic interconnections. Here, we present genomic, phylogenetic, and morphological characteristics of a symbiotic system associated with Melophagus ovinus, a member of the blood-feeding family Hippoboscidae. The system comprises four unrelated bacteria representing different stages in symbiosis evolution, from typical obligate mutualists inhabiting bacteriomes to freely associated commensals and parasites. Interestingly, the whole system provides a remarkable analogy to the association between Glossina and its symbiotic bacteria. In both, the symbiotic systems are composed of an obligate symbiont and two facultative intracellular associates, Sodalis and Wolbachia. In addition, extracellular Bartonella resides in the gut of Melophagus. However, the phylogenetic origins of the two obligate mutualist symbionts differ. In Glossina, the mutualistic Wigglesworthia appears to be a relatively isolated symbiotic lineage, whereas in Melophagus, the obligate symbiont originated within the widely distributed Arsenophonus cluster. Although phylogenetically distant, the two obligate symbionts display several remarkably similar traits (e.g., transmission via the host's "milk glands" or similar pattern of genome reduction). To obtain better insight into the biology and possible role of the M. ovinus obligate symbiont, "Candidatus Arsenophonus melophagi," we performed several comparisons of its gene content based on assignments of the Cluster of Orthologous Genes (COG). Using this criterion, we show that within a set of 44 primary and secondary symbionts, "Ca. Arsenophonus melophagi" is most similar to Wigglesworthia. On the other hand, these two bacteria also display interesting differences, such as absence of flagellar genes in Arsenophonus and their presence in Wigglesworthia. This finding implies that a flagellum is not essential for bacterial transmission via milk glands., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Background: Rickettsia felis is a recently described flea-borne spotted fever group Rickettsia that is an emerging human pathogen. Although there is information on the organism from around the world, there is no information on the organism in China., Methods: We used a commercial ELISA to detect antibodies reactive against R. felis in blood samples and developed a PCR to detect the gltA of the organism in blood samples and external parasites., Results: We found reactive antibodies in people (16%; 28/180), dogs (47%; 128/271) and cats (21%; 19/90) and positive PCRs with DNA from people (0.1%; 1/822), dogs (0.8%; 8/1,059), mice (10%; 1/10), ticks (Rhipicephalus sanguineus; 10%; 15/146), lice (Linognathus setosus; 16%; 6/37), fleas (Ctenocephalides felis felis; 95%; 57/60) and mosquitoes (Anopheles sinensis, Culex pipiens pallens; 6%; 25/428), but not from cats (0/135) or canine fecal swabs (0/43)., Conclusions: This is the first report of R. felis in China where there is serological and/ or PCR evidence of the organism in previously reported [people, dogs, cats, ticks (Rhipicephalus sanguineus), fleas (Ctenocephalides felis felis) and mosquitoes (Anopheles sinensis, Culex pipiens pallens)] and novel species [mice and lice (Linognathus setosus)].

The obligate-heritable endosymbionts of insects possess some of the smallest known bacterial genomes. This is likely due to loss of genomic material during symbiosis. The mode and rate of this erosion may change over evolutionary time: faster in newly formed associations and slower in long-established ones. The endosymbionts of human and anthropoid primate lice present a unique opportunity to study genome erosion in newly established (or young) symbionts. This is because we have a detailed phylogenetic history of these endosymbionts with divergence dates for closely related species. This allows for genome evolution to be studied in detail and rates of change to be estimated in a phylogenetic framework. Here, we sequenced the genome of the chimpanzee louse endosymbiont (Candidatus Riesia pediculischaeffi) and compared it with the closely related genome of the human body louse endosymbiont. From this comparison, we found evidence for recent genome erosion leading to gene loss in these endosymbionts. Although gene loss was detected, it was not significantly greater than in older endosymbionts from aphids and ants. Additionally, we searched for genes associated with B-vitamin synthesis in the two louse endosymbiont genomes because these endosymbionts are believed to synthesize essential B vitamins absent in the louse's diet. All of the expected genes were present, except those involved in thiamin synthesis. We failed to find genes encoding for proteins involved in the biosynthesis of thiamin or any complete exogenous means of salvaging thiamin, suggesting there is an undescribed mechanism for the salvage of thiamin. Finally, genes encoding for the pantothenate de novo biosynthesis pathway were located on a plasmid in both taxa along with a heat shock protein. Movement of these genes onto a plasmid may be functionally and evolutionarily significant, potentially increasing production and guarding against the deleterious effects of mutation. These data add to a growing resource of obligate endosymbiont genomes and to our understanding of the rate and mode of genome erosion in obligate animal-associated bacteria. Ultimately sequencing additional louse p-endosymbiont genomes will provide a model system for studying genome evolution in obligate host associated bacteria., (Copyright © 2014 Boyd et al.)

Symbiosis is a widespread biological phenomenon, and is particularly common in arthropods. Bloodsucking insects are among the organisms that rely on beneficial bacterial symbionts to complement their unbalanced diet. This review is focused on describing symbiosis, and possible strategies for the symbiont-based control of insects and insect-borne diseases, in three bloodsucking insects of medical importance: the flies of the genus Glossina, the lice of the genus Pediculus, and triatomine bugs of the subfamily Triatominae. Glossina flies are vector of Trypanosoma brucei, the causative agent of sleeping sickness and other pathologies. They are also associated with two distinct bacterial symbionts, the primary symbiont Wigglesworthia spp., and the secondary, culturable symbiont Sodalis glossinidius. The primary symbiont of human lice, Riesia pediculicola, has been shown to be fundamental for the host, due to its capacity to synthesize B-group vitamins. An antisymbiotic approach, with antibiotic treatment targeted on the lice symbionts, could represent an alternative strategy to control these ectoparasites. In the case of triatominae bugs, the genetic modification of their symbiotic Rhodococcus bacteria, for production of anti-Trypanosoma molecules, is an example of paratransgenesis, i.e. the use of symbiotic microorganism engineered in order to reduce the vector competence of the insect host.

Domestic farm animals (n=145) were sampled for the presence of ectoparasites in northwestern Peru during March, 2008. Ninety domestic animals (62%) were positive for the presence of an ectoparasite(s) and produced a total collection of the following: 728 ticks [Amblyomma maculatum, Anocentor nitens, Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus, and Otobius megnini], 12 lice (Haematopinus suis), and 3 fleas (Ctenocephalides felis). A Rickettsia genus-specific qPCR assay was performed on nucleic acid preparations of the collected ectoparasites that resulted in 5% (37/743, 35 ticks and 2 fleas) of the ectoparasites positive for the presence of Rickettsia. DNA from the positive individual ticks was tested with 2 other qPCR assays for the presence of the ompB gene in Candidatus Rickettsia andeanae or Rickettsia parkeri. Candidatus R. andeanae was found in 25 A. maculatum ticks and in two Rh. sanguineus ticks, whereas R. parkeri was detected in 6 A. maculatum ticks. Two A. maculatum were co-infected with both Candidatus R. andeanae and R. parkeri. Rickettsia felis was detected in 2 fleas, Ctenocephalides felis, by multilocus sequence typing of the 17-kD antigen and ompA genes. These findings expand the geographic range of R. parkeri to include Peru as well as expand the natural arthropod vector of Candidatus R. andeanae to include Rhipicephalus sanguineus.

Relapsing fever, caused by spirochaetes belonging to the genus Borrelia, was once the cause of worldwide epidemic zoonotic disease. This was largely through infection with the louse-borne form of the disease, caused by Borrelia recurrentis [(louse-borne relapsing fever (LBRF)]. Another form of replasing fever is caused by Borrelia duttonii [(tick-borne relapsing fever (TBRF)]. The introduction and the wide use of DDT in the last century, which is forbidden now, the incidence and prevalence of both LBRF and TBRF markedly decreased. However, with the increase of rapid transportation, crowdedness and poverty, as well as abundance of lice and ticks, replasing fever is still endemic to some countries. Besides, with the appearance of others closely related Borrelia species that begins to emerge, the threat or the burden of these arthropod-borne zoonotic may be unpredicted or underestimated.

The microsporidian Paranucleospora theridion (syn. Desmozoon lepeophtheirii) is a parasite of Atlantic salmon Salmo salar and also a hyperparasite of the salmon louse Lepeophtheirus salmonis. The parasite develops 2 types of spores in salmon, cytoplasmic spores in phagocytes and intranuclear spores in epidermal cells. The former type of development is assumed to be propagative (autoinfection), while the epidermal spores transfer the parasite to lice. Development in lice is extensive, with the formation of xenoma-like hypertrophic cells filled with microsporidian spores. We show that salmon are infected in the absence of lice, likely through waterborne spores that initiate infections in the gills. During summer and autumn the parasite propagates in the kidney, as evidenced by peaking normalised expression of P. theridion rRNA. Lice become infected during autumn, and develop extensive infections during winter. Lice mortality in winter and spring is likely responsible for a reservoir of spores in the water. Salmon transferred to sea in November (low temperature) did not show involvement of the kidney in parasite propagation and lice on such fish did not become infected. Apparently, low temperatures inhibit normal P. theridion development in salmon.

Introduction: Ectoparasites are the main vectors of rickettsiosis. In Panama, however, limited data are available concerning the arthropod species that serve as vectors or reservoirs., Objectives: Data are presented concerning the presence of Rickettsia in ectoparasites of wildlife and domestic animals in the Cerro Chucantí private nature reserve and in neighboring villages., Materials and Methods: Nine humans, 95 domestic mammals and 48 wild mammals were examined. Twenty-one species of ectoparasites were obtained, including fleas, lice, ticks and mites. These were preserved in 95% ethanol. Later, the DNA was extracted from the ticks and fleas and analyzed by molecular techniques to detect presence of Rickettsia., Results: Of a total of 425 PCR reactions, 270 were positive for Rickettsia and 155 negative. Among the positive samples, 86 PCR amplified for the gltA gene (55% of positives) and 41 of these also amplified the ompA gene. DNA of Rickettsia amblyommii was found in horses ticks (Amblyomma cajennense, Dermacentor nitens), dogs ticks (Rhipicephalus sanguineus) and free living nymphs in the forest. Additionally, DNA of R. felis was found in fleas from dogs Ctenocephalides felis., Conclusions: The presence of R. amblyommii and R. felis was detected in ticks and fleas of domestic animals in villages near Cerro Chucanti; however no Rickettsia DNA was found in ectoparasites of non-domestic wildlife.

Several of the infectious diseases associated with human lice are life-threatening, including epidemic typhus, relapsing fever, and trench fever, which are caused by Rickettsia prowazekii, Borrelia recurrentis, and Bartonella quintana, respectively. Although these diseases have been known for several centuries, they remain a major public health concern in populations living in poor-hygiene conditions because of war, social disruption, severe poverty, or gaps in public health management. Poor-hygiene conditions favour a higher prevalence of body lice, which are the main vectors for these diseases. Trench fever has been reported in both developing and developed countries in populations living in poor conditions, such as homeless individuals. In contrast, outbreaks of epidemic typhus and epidemic relapsing fever have occurred in jails and refugee camps in developing countries. However, reports of a significantly high seroprevalence for epidemic typhus and epidemic relapsing fever in the homeless populations of developed countries suggest that these populations remain at high risk for outbreaks of these diseases. Additionally, experimental laboratory studies have demonstrated that the body louse can transmit other emerging or re-emerging pathogens, such as Acinetobacter baumannii and Yersinia pestis. Therefore, a strict survey of louse-borne diseases and the implementation of efficient delousing strategies in these populations should be public health priorities., (© 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.)

Recent studies of molecular and genomic data from the parasitic lice of birds and mammals, as well as their mutualistic endosymbiotic bacteria, are changing the phylogenetic relationships and taxonomy of these organisms. Phylogenetic studies of lice suggest that vertebrate parasitism arose multiple times from free-living book and bark lice. Molecular clocks show that the major families of lice arose in the late Mesozoic and radiated in the early Cenozoic, following the radiation of mammals and birds. The recent release of the human louse genome has provided new opportunities for research. The genome is being used to find new genetic markers for phylogenetics and population genetics, to understand the complex evolutionary relationships of mitochondrial genes, and to study genome evolution. Genomes are informing us not only about lice, but also about their obligate endosymbiotic bacteria. In contrast to lice and their hosts, lice and their endosymbionts do not share common evolutionary histories, suggesting that endosymbionts are either replaced over time or that there are multiple independent origins of symbiosis in lice. Molecular phylogenetics and whole genome sequencing have recently provided the first insights into the phylogenetic placement and metabolic characteristics of these distantly related bacteria. Comparative genomics between distantly related louse symbionts can provide insights into conserved metabolic functions and can help to explain how distantly related species are fulfilling their role as mutualistic symbionts. In lice and their endosymbionts, molecular data and genome sequencing are driving our understanding of evolutionary relationships and classification, and will for the foreseeable future., (© 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.)

Although Mongolia is regarded as one of the possible places of plague radiation, only few data are available from Mongolian Yersinia pestis strains. In this study a total of 100 Mongolian Y. pestis strains isolated from wild mammals and their parasites between the years 1960 and 2007 were analyzed for their phenotype. All strains grew well on selective Cefsulodin-Irgasan-Novobiocin agar and were positive for the F1-antigen, the F1-gene (caf1), and the plasminogen activator gene (pla). Biochemical analyses using the API20E® system identified 93% of the strains correctly as Y. pestis. The BWY in-house system consisting of 38 biochemical reactions was used to differentiate among Y. pestis subspecies pestis biovars Antiqua and Medievalis and also between the subspecies microtus biovars Ulegeica and Caucasica. Antibiotic susceptibility testing according to Clinical and Laboratory Standards Institute-guidelines identified one strain as being multiresistant. This strain was isolated from a wildlife rodent with no anthropogenic influence and thus suggests naturally acquired resistance.

Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors Ctenocephalides orientis and Ctenocephalides felis felis were infected with R. felis. The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsia detected in two Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both R. felis and B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

This study was conducted to determine the presence of Acinetobacter and Rickettsia species DNA in lice and Melophagus ovinus (sheep ked) of animals from Oromia Regional State in Ethiopia. From September through November 2011, a total of 207 cattle, 85 sheep, 47 dogs and 16 cats were examined for ectoparasites. Results of morphological identification revealed several species of ectoparasites: Linognathus vituli (L. vituli), Bovicola bovis (B. bovis) and Solenopotes capillatus (S. capillatus) on cattle; B. ovis and Melophagus ovinus (M. ovinus) on sheep; and Heterodoxus spiniger (H. spiniger) on dogs. There was a significantly (p≤0.0001) higher prevalence of L. vituli observed in cattle than both S. capillatus and B. bovis. Molecular identification of lice using an 18S rRNA gene analysis confirms the identified lice species by morphological methods. We detected different Acinetobacter species among lice (11.1%) and keds (86.4%) including A. soli in L. vituli of cattle, A. lowffii in M. ovinus of sheep, A. pittii in H. spiniger of dogs, 1 new Acinetobacter spp. in M. ovinus and 2 new Acinetobacter spp. in H. spiniger of dogs using partial rpoB gene sequence analysis. There was a significantly higher prevalence of Acinetobacter spp. in keds than in lice (p≤0.00001). Higher percentage of Acinetobacter spp. DNA was detected in H. spiniger than in both B. ovis and L. vituli (p≤0.00001). Carbapenemase resistance encoding genes for blaOXA-23, blaOXA-24, blaOXA-58, blaNDM-1 and blaOXA-51 were not found in any lice and keds. These findings suggest that synanthropic animals and their ectoparasites might increase the risk of human exposure to zoonotic pathogens and could be a source for Acinetobacter spp. infections in humans. However, additional epidemiological data are required to determine whether ectoparasites of animals can act as environmental reservoirs and play a role in spreading these bacteria to both animal and human hosts.

Mainly through vector transmission, domestic cats and dogs are infected by several Bartonella spp. and represent a large reservoir for human infections. This study investigated the relationship of prevalences of Bartonella infection in shelter dogs and cats and various ectoparasite species infesting them (fleas, ticks, and lice). Moreover, relationships between Bartonella infection and animal gender and age and presence of ectoparasites were analyzed. Blood samples were collected from 120 dogs and 103 cats. There were 386 ticks and 36 fleas harvested on these dogs, and 141 fleas, 4 ticks, and 2 lice harvested on these cats. Isolation/detection of Bartonella sp. was performed by culture, polymerase chain reaction (PCR), and partial sequencing. Bartonella was isolated from 21 (20.4%) cats and detected by PCR from 20 (19.4%) cats, 2 (1.7%) dogs, 55 (39%) fleas collected from cats, 28 (10%) ticks DNA samples, and 1 (2.8%) flea collected from dogs. When combining culture and PCR data, 27 cats and 55 fleas collected on cats were positive for Bartonella henselae or Bartonella clarridgeiae, but none were coinfected. Approximately half of the B. henselae isolates from 21 cats were B. henselae type I. Moreover, B. henselae, Bartonella phoceensis, Bartonella queenslandensis, Bartonella rattimassiliensis, Bartonella elizabethae DNA was detected in ticks collected from dogs and one flea was B. clarridgeiae PCR positive. This is the first report of such a wide variety of Bartonella spp. detected in Rhipicephalus sanguineus. Further studies are required to understand the relative importance of these ectoparasites to transmit Bartonella spp. in dogs and cats.

A wide range of blood-sucking arthropods have either been confirmed or are suspected as important vectors in Bartonella transmission to mammals, including humans. Overall, it appears that the diversity of Bartonella species DNA identified in ectoparasites is much broader than the species detected in their mammalian hosts, suggesting a mechanism of adaptation of Bartonella species to their host-vector ecosystem. However, these mechanisms leading to the fitness between the vectors and their hosts still need to be investigated., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR., Methods: We identified a mass grave in Douai, France dating from the early XVIII(th) century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples., Results and Discussion: In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XX(th) century., Conclusion: Louse-borne outbreaks were raging during the XVIII(th) century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America.

Background: Bartonella is the agent of cat-scratch disease, but is also responsible for more severe conditions such as retinitis, meningoencephalitis, endocarditis and bacillary angiomatosis. Its seroprevalence is unknown in Brazil., Methods: Patients in an AIDS clinic, asymptomatic at the time of the study, were enrolled prospectively. They answered a structured questionnaire and had blood taken for serological and molecular assays. Cat breeder's pets were tested serologically and collected ectoparasites were tested by molecular biology techniques. Blood donors, paired by age and sex, were tested for Bartonella IgG antibodies., Results: 125 HIV positive patients with a median age of 34 were studied; 61 were male and 75% were on HAART. Mean most recent CD4 count was 351-500 cells/mm(3). A high rate of contact with ticks, fleas and lice was observed. Bartonella IgG seroreactivity rate was 38.4% in HIV positive individuals and breeding cats was closely associated with infection (OR 3.6, CI 1.1-11.9, p<0.05). No difference was found between the sexes. Titers were 1:32 in 39 patients, 1:64 in seven, 1:128 in one and 1:256 in one. In the control group, IgG seroreactivity to Bartonella spp. was 34%, and female sex was correlated to seropositivity. Fourteen of 61 (23%) males vs 29/64 (45.3%) females were seroreactive to Bartonella (OR 2.8, CI 1.2-6.5, p<0.01). Titers were 1:32 in 29 patients, 1:64 in ten and 1:128 in four., Conclusions: Bartonella spp. seroprevalence is high in HIV positive and in blood donors in Rio de Janeiro. This may be of public health relevance., (2010 Elsevier B.V. All rights reserved.)

To explore whether harbor seals (Phoca vitulina) are exposed to Bartonella spp., 35 seal lice (Echinophtirius horridus) were collected from seven seals, during their rehabilitation period in the Seal Rehabilitation and Research Center at Pieterburen, The Netherlands. Forty-eight spleen samples were collected during necropsies of other harbor seals that died during rehabilitation, or had stranded dead and were brought to the Seal Rehabilitation and Research Center for postmortem investigation. Lice were grouped into six pools, and DNA was extracted from each pool and from all the seals' spleen samples. One of the six lice pools and one spleen sample were found positive by high-resolution melt, real-time PCR amplifying partial loci of the rpoB gene, and the intergenic spacer (ITS) region. The Bartonella spp. identified in the spleen and lice were found to be identical to each other. One hundred percent sequence similarity with Bartonella henselae was found in the ITS, and 97% sequence similarity with Bartonella grahamii was detected in the rpoB gene. To the best of the authors' knowledge, this is the first report describing the detection of Bartonella spp. from a seal or any other pinniped, and from seal lice, E. horridus. The 100% sequence similarity in the ITS of the Bartonella sp. identified with the zoonotic B. henselae warrants further investigation and characterization of this organism, which may be found to be of public health importance.

In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed.

We describe the epidemiological and clinical aspects of louse-borne relapsing fever (LBRF) in a series of children attending in a rural hospital in Ethiopia during 1997-2007. From a total of 249 cases of LBRF, 154 (61.4%) were children (<15 years). The most frequent symptoms were: fever, headache, dizziness and musculoskeletal pains. The overall case fatality rate was 2.4 (10% for patients <1.1 years; 3.4% for 1.1 to 4.0 years; and 0% >4.0 years [P = 0.05]). The mortality in children was less than in adults (13.2%) (P = 0.003).

In an effort to understand how a tick-borne pathogen adapts to the body louse, we sequenced and compared the genomes of the recurrent fever agents Borrelia recurrentis and B. duttonii. The 1,242,163-1,574,910-bp fragmented genomes of B. recurrentis and B. duttonii contain a unique 23-kb linear plasmid. This linear plasmid exhibits a large polyT track within the promoter region of an intact variable large protein gene and a telomere resolvase that is unique to Borrelia. The genome content is characterized by several repeat families, including antigenic lipoproteins. B. recurrentis exhibited a 20.4% genome size reduction and appeared to be a strain of B. duttonii, with a decaying genome, possibly due to the accumulation of genomic errors induced by the loss of recA and mutS. Accompanying this were increases in the number of impaired genes and a reduction in coding capacity, including surface-exposed lipoproteins and putative virulence factors. Analysis of the reconstructed ancestral sequence compared to B. duttonii and B. recurrentis was consistent with the accelerated evolution observed in B. recurrentis. Vector specialization of louse-borne pathogens responsible for major epidemics was associated with rapid genome reduction. The correlation between gene loss and increased virulence of B. recurrentis parallels that of Rickettsia prowazekii, with both species being genomic subsets of less-virulent strains., Competing Interests: The authors have declared that no competing interests exist.

To assess the role of virulence factors identified in Caenorhabditis elegans in the transmission of plague by lice, we infected 100 lice by feeding them on rabbits and made them bacteremic; the rabbits had been intravenously inoculated with 10(9) CFU of six different mutant Yersinia pestis strains of lower pathogenicity for C. elegans, obtained from the KIM5 strain. This strain lacks genes used for biofilm formation. High mortality rates were observed in all lice, which excreted viable bacteria in their feces. Mutants killed rabbits when infected intravenously, but mutants were not transmitted to rabbits by infected lice. We conclude that the genes governing pathogenicity in C. elegans and louse are not identical.