| a comparative study of three methods of detection of borrelia crocidurae in wild rodents in senegal. | in a rural area in sénégal with a high incidence of tick-borne relapsing fever in humans, borrelia crocidurae was studied in the blood and brain of wild rodents (mastomys erythroleucus, arvicanthis niloticus and rattus rattus) using 3 methods: (i) direct examination of thick blood films; (ii) intraperitoneal inoculation of blood into white mice; (iii) intraperitoneal inoculation of homogenized cerebral tissue into white mice. of the 82 rodents examined, the proportion of infected animals was res ... | 1994 | 7570827 |
| the spread of tick-borne borreliosis in west africa and its relationship to sub-saharan drought. | in west africa, tick-borne relapsing fever is due to the spirochete borrelia crocidurae and its geographic distribution is classically limited to the sahel and saharan regions where the vector tick alectorobius sonrai is distributed. we report results of epidemiologic investigations carried out in the sudan savanna of senegal where the existence of the disease was unknown. a two-year prospective investigation of a rural community indicated that 10% of the study population developed an infection ... | 1996 | 8600768 |
| phylogenetic analysis of borrelia species based on flagellin gene sequences and its application for molecular typing of lyme disease borreliae. | we determined almost complete flagellin gene sequences of various borrelia species and aligned them with previously published sequences. a neighbor-joining phylogenetic analysis showed that the genus borrelia was divided into the following three major clusters: new world relapsing fever borreliae (borrelia turicatae, borrelia parkeri, and borrelia hermsii), old world relapsing fever borreliae (borrelia crocidurae, borrelia duttonii, and borrelia hispanica), and lyme disease borreliae (borrelia b ... | 1996 | 8863416 |
| the spirochete borrelia crocidurae causes erythrocyte rosetting during relapsing fever. | several species of the genus borrelia exhibit antigenic variation of variable major proteins on their surface during relapsing fever. we have investigated the african relapsing fever species borrelia crocidurae during infections in mice and compared it with the thoroughly studied north american species borrelia hermsii. a major difference between the two species is that b. crocidurae can bind and become completely covered with erythrocytes. in addition, b. crocidurae causes a prolonged spirochet ... | 1998 | 9453646 |
| tick-borne relapsing fever imported from west africa: diagnosis by quantitative buffy coat analysis and in vitro culture of borrelia crocidurae. | west african tick-borne relapsing fever (tbrf) is difficult to diagnose due to the low number of spirochetes in the bloodstream of patients. previously, the causative microorganism, borrelia crocidurae, had never been cultured in vitro. tbrf was rapidly diagnosed for two patients returning from western africa with fever of unknown origin by quantitative buffy coat (qbc) analysis. diagnosis was confirmed by intraperitoneal inoculation of blood specimens from patients into laboratory mice. in vitr ... | 1999 | 10325370 |
| erythrocyte-aggregating relapsing fever spirochete borrelia crocidurae induces formation of microemboli. | the african relapsing fever spirochete borrelia crocidurae forms aggregates with erythrocytes, resulting in a delayed immune response. mice were infected with b. crocidurae and monitored during 50 days after infection. spirochetes were observed extravascularly at day 2 after infection. two days later, inflammatory responses, cell death, and tissue damage were evident. the pathologic responses in lungs and kidneys were similar, whereas the symptoms in the brains were delayed, with a less pronounc ... | 1999 | 10558950 |
| the relapsing fever spirochaete, borrelia crocidurae, activates human endothelial cells and promotes the transendothelial migration of neutrophils. | the blood-borne, erythrocyte-aggregating borrelia crocidurae, the causative agent of african relapsing fever, have been shown to induce severe cellular lesions in mice. in this paper, we present the first report of how the endothelium is stimulated during an african relapsing fever b. crocidurae infection. b. crocidurae co-incubated with cultured human umbilical vein endothelial cells (huvecs) activated endothelium in such way that e-selectin and intercellular adhesion molecule 1 (icam-1) became ... | 2000 | 11207611 |
| testicular damage by microcirculatory disruption and colonization of an immune-privileged site during borrelia crocidurae infection. | the agent of african relapsing fever, borrelia crocidurae, causes reversible multiple organ damage. we hypothesize that this damage is caused when the spirochete forms aggregate with erythrocytes in vivo, creating rosettes that plug the microcirculatory system. to test this hypothesis, we compared testicular microcirculation over an extended time period in two groups of rats: one experimentally inoculated with b. crocidurae, the other with the nonerythrocyte rosette-forming borrelia hermsii. in ... | 2001 | 11342584 |
| delayed invasion of the kidney and brain by borrelia crocidurae in plasminogen-deficient mice. | borrelia crocidurae is an etiologic agent of relapsing fever in africa and is transmitted to humans by the bite of soft ticks of the genus ornithodoros. the role of the plasminogen (plg) activation system for the pathogenicity of b. crocidurae was investigated by infection of plg-deficient (plg(-/-)) and plg wild-type (plg(+/+)) mice. no differences in spirochetemia were observed between the plg(-/-) and plg(+/+) mice. however, signs indicative of brain invasion, such as neurological symptoms an ... | 2001 | 11500461 |
| arvicanthis niloticus desmarest, 1822, a new host for borrelia crocidurae in egypt. | | 1963 | 14028028 |
| [studies on the behavior of relapsing fever spirochetes especially the borrelia crocidurae group in the body louse. 2]. | | 1963 | 14047093 |
| [the preservation of an egyptian strain of borrelia crocidurae in ornithodorus moubata]. | | 1963 | 14111369 |
| [use of the guinea pig in the differentiation of relapsing fever spirocheta; the individuality of the borrelia crocidurae group]. | | 1954 | 14378931 |
| identifying relapsing fever borrelia, senegal. | we describe a nested polymerase chain reaction for the identification of borrelia species from serum of patients with unidentified fevers. this technique, based on single nucleotide polymorphisms of the 16s ribosomal rna gene, was used to test blood samples from 7,750 patients, 33 of whom were diagnosed with spirochete infections. borrelia crocidurae was the only species identified. | 2005 | 15757570 |
| the loss and gain of marginal zone and peritoneal b cells is different in response to relapsing fever and lyme disease borrelia. | t cell-independent abs are protective against lyme disease and relapsing fever, illnesses caused by borrelia spirochetes with distinct blood-borne phases of infection. to understand this protective response, we characterized splenic and peritoneal b cell compartments during infection using flow cytometry and immunohistochemistry. in the spleen, early after infection, borrelia crocidurae, a relapsing fever species, induced a striking loss of marginal zone (mz) b cells from the mz, while borrelia ... | 2009 | 19109181 |
| borrelia crocidurae infection of ornithodoros erraticus (lucas, 1849) ticks in tunisia. | tick-borne relapsing fever (tbrf) is caused by borrelia species transmitted to humans by infected ornithodoros sp. ticks. the disease has been rarely described in north africa, and in tunisia the local transmission of tbrf seems to have disappeared or is undiagnosed. a longitudinal study was conducted in 14 sites located in four different bioclimatic zones of tunisia to assess both the distribution of ornithodoros sp. and their infection rate with the relapsing fever borrelia sp. three polymeras ... | 2010 | 20420529 |
| molecular identification of borrelia crocidurae in a patient returning from senegal. | borrelia spp. are pathogens responsible for worldwide tickborne relapsing fever (tbrf). in west africa, tbrf is due to a single species, borrelia crocidurae, transmitted by the soft-body tick ornithodoros sonrai. we report a case of b crocidurae infection in a french tourist in senegal, diagnosed by molecular biology using 16s rdna, flab, and the 16s-23s intergenic spacer. we found six imported cases reported in travellers (since 1999). we review here clinical and molecular aspects and pathophys ... | 2009 | 21691399 |
| endemic foci of the tick-borne relapsing fever spirochete borrelia crocidurae in mali, west africa, and the potential for human infection. | tick-borne relapsing fever spirochetes are maintained in endemic foci that involve a diversity of small mammals and argasid ticks in the genus ornithodoros. most epidemiological studies of tick-borne relapsing fever in west africa caused by borrelia crocidurae have been conducted in senegal. the risk for humans to acquire relapsing fever in mali is uncertain, as only a few human cases have been identified. given the high incidence of malaria in mali, and the potential to confuse the clinical dia ... | 2012 | 23209863 |
| multiplex real-time pcr diagnostic of relapsing fevers in africa. | in africa, relapsing fever borreliae are neglected arthropod-borne pathogens causing mild to deadly septicemia and miscarriage. the closely related borrelia crocidurae, borrelia duttonii, borrelia recurrentis and borrelia hispanica are rarely diagnosed at the species level, hampering refined epidemiological and clinical knowledge of the relapsing fevers. it would be hugely beneficial to have simultaneous detection and identification of borrelia to species level directly from clinical samples. | 2013 | 23390560 |
| maldi-tof mass spectrometry detection of pathogens in vectors: the borrelia crocidurae/ornithodoros sonrai paradigm. | in africa, relapsing fever borreliae are neglected vector-borne pathogens that cause mild to deadly septicemia and miscarriage. screening vectors for the presence of borreliae currently requires technically demanding, time- and resource-consuming molecular methods. matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof-ms) has recently emerged as a tool for the rapid identification of vectors and the identification of cultured borreliae. we investigated whether m ... | 2014 | 25058611 |
| african relapsing fever borreliae genomospecies revealed by comparative genomics. | relapsing fever borreliae are vector-borne bacteria responsible for febrile infection in humans in north america, africa, asia, and in the iberian peninsula in europe. relapsing fever borreliae are phylogenetically closely related, yet they differ in pathogenicity and vectors. their long-term taxonomy, based on geography and vector grouping, needs to be re-apprised in a genomic context. we therefore embarked into genomic analyses of relapsing fever borreliae, focusing on species found in africa. | 2014 | 25229054 |
| laboratory diagnosis of tick-borne african relapsing fevers: latest developments. | in africa, relapsing fevers caused by ectoparasite-borne borrelia species are transmitted by ticks, with the exception of borrelia recurrentis, which is a louse-borne spirochete. these tropical diseases are responsible for mild to deadly spirochetemia. cultured borrelia crocidurae, borrelia duttonii, and borrelia hispanica circulate alongside at least six species that have not yet been cultured in vectors. direct diagnosis is hindered by the use of non-specific laboratory tools. indeed, microsco ... | 2015 | 26618151 |
| blood-borne candidatus borrelia algerica in a patient with prolonged fever in oran, algeria. | to improve the knowledge base of borrelia in north africa, we tested 257 blood samples collected from febrile patients in oran, algeria, between january and december 2012 for borrelia species using flagellin gene polymerase chain reaction sequencing. a sequence indicative of a new borrelia sp. named candidatus borrelia algerica was detected in one blood sample. further multispacer sequence typing indicated this borrelia sp. had 97% similarity with borrelia crocidurae, borrelia duttonii, and borr ... | 2015 | 26416117 |
| monoclonal antibodies for the diagnosis of borrelia crocidurae. | relapsing fever borreliae, produced by ectoparasite-borne borrelia species, cause mild to deadly bacteremia and miscarriage. in the perspective of developing inexpensive assays for the rapid detection of relapsing fever borreliae, we produced 12 monoclonal antibodies (mabs) against borrelia crocidurae and characterized the two exhibiting the highest titers. p3a10 mab reacts with the 35.6-kda flagellin b (flab) of b. crocidurae while p6d9 mab recognizes a 35.1-kda variable-like protein (vlp) in b ... | 2016 | 26598566 |
| the epidemiology and geographic distribution of relapsing fever borreliosis in west and north africa, with a review of the ornithodoros erraticus complex (acari: ixodida). | relapsing fever is the most frequent bacterial disease in africa. four main vector / pathogen complexes are classically recognized, with the louse pediculus humanus acting as vector for b. recurrentis and the soft ticks ornithodoros sonrai, o. erraticus and o. moubata acting as vectors for borrelia crocidurae, b. hispanica and b. duttonii, respectively. our aim was to investigate the epidemiology of the disease in west, north and central africa. | 2013 | 24223812 |
| ubiquitous bacteria borrelia crocidurae in western african ticks ornithodoros sonrai. | in west africa, tick-borne relapsing fever is a neglected arthropod-borne infection caused by borrelia crocidurae transmitted by the argasid tick ornithodoros sonrai. from an epidemiological point of view, it is of interest to know whether some genotypes of the vector are specialized in carrying certain genotypes of the pathogen. | 2015 | 26382232 |
| complete genome sequence of borrelia crocidurae. | we announce the draft genome sequence of borrelia crocidurae (strain achema). the 1,557,560-bp genome (27% gc content) comprises one 919,477-bp linear chromosome and 638,083-bp plasmids that together carry 1,472 open reading frames, 32 trnas, and three complete rrnas, with almost complete colinearity between b. crocidurae and borrelia duttonii chromosomes. | 0 | 22740657 |
| borrelia crocidurae infection in acutely febrile patients, senegal. | as malaria cases in africa decline, other causes of acute febrile illness are being explored. to determine incidence of borrelia crocidurae infection during june 2010-october 2011, we collected 1,566 blood specimens from febrile patients in senegal. incidence was high (7.3%). new treatment strategies, possibly doxycycline, might be indicated for febrile patients. | 2014 | 25062495 |
| borrelia crocidurae meningoencephalitis, west africa. | borrelia crocidurae-associated relapsing fever is endemic to west africa and is considered benign. we report 4 patients with b. crocidurae-associated neurologic symptoms; 2 of their cases had been misdiagnosed. frequency and severity of this disease could be underestimated; molecular methods and serodiagnostic tests for lyme disease might be helpful in its detection. | 2013 | 23347436 |
| genome sequence of borrelia crocidurae strain 03-02, a clinical isolate from senegal. | the draft genome sequence of borrelia crocidurae strain 03-02, a blood isolate from a febrile senegalese patient, comprises a 920,021-bp linear chromosome (27.7% g+c content), 32 trnas, 818 open reading frames, and one cluster of regularly interspaced short palindromic repeats. its genotype differs from that of the achema reference strain. | 2014 | 25377717 |
| multispacer sequence typing relapsing fever borreliae in africa. | in africa, relapsing fevers are neglected arthropod-borne infections caused by closely related borrelia species. they cause mild to deadly undifferentiated fever particularly severe in pregnant women. lack of a tool to genotype these borrelia organisms limits knowledge regarding their reservoirs and their epidemiology. | 2012 | 22679518 |
| relapsing fever borreliae in africa. | the study of relapsing fever borreliae in africa has long suffered from the use of non-specific laboratory tools for the direct detection of these spirochetes in clinical and vector specimens. accordingly, borrelia hispanica, borrelia crocidurae, borrelia duttonii, and borrelia recurrentis have traditionally been distinguished on the basis of geography and vector and the unproven hypothesis that each species was exclusive to one vector. the recent sequencing of three relapsing fever borrelia gen ... | 2013 | 23926141 |
| new concepts for the old challenge of african relapsing fever borreliosis. | relapsing fever, caused by spirochaetes belonging to the genus borrelia, was once the cause of worldwide epidemic disease. this was largely through infection with the louse-borne form of the disease, caused by borrelia recurrentis (louse-borne relapsing fever (lbrf)). during the last century, we have witnessed the demise of this infection, largely owing to improved standards of living and the introduction of the insecticide ddt, resulting in a reduction in the incidence of the body louse, the ve ... | 2009 | 19489922 |
| tickborne relapsing fever diagnosis obscured by malaria, togo. | given the prevalence of relapsing fever (rf) in senegal, this disease may cause illness and death in other areas of west africa. we performed a cross-sectional, clinic-based study to investigate the presence of rf in togo during 2002-2004. blood samples from patients with fever were examined for rf spirochetes by microscopy, pcr, and dna sequencing of amplicons and for antibodies to the glycerophosphodiester phosphodiesterase antigen. although no spirochetes were seen in blood smears, approximat ... | 2007 | 17370524 |
| molecular divergences of the ornithodoros sonrai soft tick species, a vector of human relapsing fever in west africa. | the soft tick ornithodoros sonrai is recognized as the only vector of borrelia crocidurae causing human relapsing fever in west africa. its determination has been exclusively based on morphological features, geographical distribution and vector competence. some ambiguities persist in its systematics and may cause misunderstanding about west african human relapsing fevers epidemiology. by amplifying and aligning 16s and 18s rdna genes in o. sonrai specimens collected from 14 distinct sites in sen ... | 2006 | 16962358 |
| incidence of tick-borne relapsing fever in west africa: longitudinal study. | the ongoing drought in sub-saharan countries has led to the colonisation of west african savanna by ornithodoros sonrai; this tick acts as a vector for borrelia crocidurae, which causes tick-borne relapsing fever (tbrf). our aim was to ascertain the incidence of tbrf in west africa. | 2006 | 16815378 |
| relapsing fever in a traveller from senegal: determination of borrelia species using molecular methods. | we describe a case of a febrile patient returning from senegal in which haemoscopic and molecular investigation confirmed tick-borne relapsing fever (tbrf), suggesting borrelia crocidurae as the causative agent. this case emphasises the need to include tbrf in the differential diagnosis of fever following a journey from endemic countries, including malarial areas. | 2006 | 16455121 |
| [west african tick-borne relapsing fever]. | west african tick-borne relapsing fever is an endemic disease due to borrelia crocidurae. the tick alectorobius sonrai is the only known vector of this bacterium. several species of rodents and insectivores may be reservoir for this spirochete. the geographic distribution of borrelia crocidurae is not well known. the zone where the presence of the vector has been recorded is situated in sahelian regions, from mauritania and northern senegal up to chad. in senegal, it has been shown that the pers ... | 2003 | 14671751 |
| phylogenesis of relapsing fever borrelia spp. | the phylogenetic relationships of 20 relapsing fever (rf) borrelia spp. were estimated on the basis of the sequences of rrs genes. complete sequences were aligned and compared with previously published sequences, and the similarity values were found to be 97.7 to 99.9%. phylogenetic trees were constructed by using the three neighbor-joining, maximum-parsimony, and maximum-likelihood methods. the results of the comparative phylogenetic analysis divided the rf borrelia spp. into three major cluste ... | 1996 | 8863409 |
| a longitudinal survey of borrelia crocidurae prevalence in rodents and insectivores in senegal. | we report results of a longitudinal survey designed to determine the importance and the dynamics of borrelia crocidurae, the spirochete responsible for tick-borne relapsing fever in west africa in rodents and insectivores in a rural area of northern senegal. a total of 954 animals were caught during bimonthly capture sessions over a two-year period. positive thick blood smears were recorded in 17.6% of the 740 rodents and 7.3% of the 55 musk shrews tested. variations of prevalence were analyzed ... | 1994 | 8116808 |
| borrelia crocidurae: venereal transfer in egyptian ornithodoros erraticus ticks. | | 1982 | 6889976 |
| hyperparasitism in ornithodoros erraticus. | hyperparasitism is common in laboratory colonies of egyptian ornithodoros erraticus whether the ticks are on or off the rodent host. sex, recent engorgement, and size appear to be major factors in this feeding relationship. males, and nymphs that produced males (n-male), parasitized females and nymphs that produced females (n-female) more frequently than they parasitized males and n-male. females and n-female seldom parasitized females and n-female and did not parasitize males or n-male. engorgi ... | 1983 | 6827441 |
| borrelia crocidurae localization and transmission in ornithodoros erraticus and o. savignyi. | borrelia crocidurae infection rates in different organs of adult ornithodoros (pavlovskyella) erraticus and o. (ornithodoros) savignyi were studied at intervals during a 60-day period following an infective meal. the spirochaetes persisted in tick guts for 1 month, were first observed in other organs 1-7 days post-feeding, and persisted for 20-60 days in different organs. the ovaries, gene's organ, testes and male accessory glands of only o. erraticus were infected. the infection rates in adult ... | 1984 | 6739127 |
| seasonal dynamics of ornithodoros (pavlovskyella) erraticus (acari: ixodoidea: argasidae) and the spirochete borrelia crocidurae in egypt. | | 1984 | 6502613 |
| experimental studies on the replication and dissemination of qalyub virus (bunyaviridae: nairovirus) in the putative tick vector, ornithodoros (pavlovskyella) erraticus. | a study was undertaken to determine if the argasid tick, ornithodoros (pavlovskyella) erraticus, can serve as a biological vector of qalyub (qyb) virus. the suckling mice used as viremic vertebrate hosts were acceptable hosts for all feeding stages of this tick and developed relatively high titered viremias (4.4-6.5 log10pfu/ml) 24-120 hr post intracerebral inoculation. larval, nymphal, and adult ticks became orally infected with qyb virus after ingesting 4.4-6.4 log10pfu/ml. the overall infecti ... | 1985 | 3918473 |
| tick-borne borreliosis in west africa. | reported cases of tick-borne relapsing fever due to the spirochaete borrelia crocidurae are rare in west africa, and few epidemiological data are available. to see how common relapsing fever is in senegal thick blood smears from cases of fever of unknown origin and from randomly selected clinic outpatients from a rural dispensary were examined for borrelia. the prevalence of borrelia infections in small mammals was also assessed. borrelia was seen in smears of 12 (0.9%) of 1340 children. all chi ... | 1991 | 1671481 |
| borrelia crocidurae in ornithodoros ticks from northwestern morocco: a range extension in relation to climatic change? | tick-borne relapsing fever (tbrf) is caused by borrelia spirochetes transmitted to humans by argasid soft ticks of the genus ornithodoros. we investigated the presence of ornithodoros ticks in rodent burrows in nine sites of the gharb region of northwestern morocco where we recently documented a high incidence of tbrf in humans. we assessed the borrelia infection rate by nested pcr and sequencing. all sites investigated were colonized by ticks of the ornithodoros marocanus complex and a high pro ... | 2014 | 25424260 |
| borrelia infection in small mammals in west africa and its relationship with tick occurrence inside burrows. | tick-borne relapsing fever (tbrf) is a zoonotic disease caused by several borrelia species transmitted to humans by ornithodoros tick vectors. in west africa, borrelia crocidurae is a common cause of disease in many rural populations. small mammals act as reservoirs of infection. we report here the results of surveys that investigated the occurrence of b. crocidurae infection in rodents and insectivores from eight countries of west and central africa. animals were identified at the species level ... | 2015 | 26327444 |
| plasmodium falciparum malaria co-infection with tick-borne relapsing fever in dakar. | west african tick-borne relapsing fever (tbrf) due to borrelia crocidurae and malaria are co-endemics in senegal. although expected to be high, co-infections are rarely reported. a case of falciparum malaria and b. crocidurae co-infection in a patient from velingara (south of senegal) is discussed. | 2017 | 28077149 |