Polymerase chain reaction in detection of human granulocytic ehrlichiosis (HGE) agent DNA in Ixodes ricinus ticks

PCR, or polymerase chain reaction, is the most hoped-for diagnostic method for ehrlichiosis detection. In European molecular laboratories, the gene encoding 16S rRNA for ribosomal small subunit has been the most frequently used Ehrlichia DNA marker. Due to a lack of PCR standardization, this work compares sensitivity of two pairs of primers that amplify the 16S rDNA gene fragments.

Inhibitors of benzamidine type influence the virulence properties of Porphyromonas gingivalis strains

Synthetic inhibitors of benzamidine type have been found to have inhibiting effects on arginine specific cysteine proteinases of P. gingivalis. The purpose of our study was to assess the effects of these inhibitors on the virulence properties of two P. gingivalis strains, the reference strain ATCC 33277 and JH16-1, a clinical isolate obtained from a patient with severe periodontitis. The inhibitors tested were pentamidine, benzamidine, three bis-benzamidine derivatives with a pentamidine-related structure, one bis-benzamidine derivative with another structure, and one arginine derivative as a negative control, each in the concentrations of 2 microM and 20 microM. As virulence criteria the following parameters were determined: arginine-specific amidolytic activity, growth inhibition, hemagglutination of sheep erythrocytes, adherence to KB cells and immuno-phagocytosis including intracellular killing. Pentamidine and the bis-benzamidine derivatives with pentamidine-related structure showed the most remarkable effects on reduction of amidolytic activity by 35%, growth inhibition and reduced hemagglutination. Except for the arginine derivative all other inhibitors tested enhanced the phagocytosis capacities of granulocytes. No clear influence of the inhibitors on adherence of P. gingivalis to KB cells was seen. Although in vitro effects of the synthetic inhibitors of cysteine proteinases on virulence of P. gingivalis were observed further in vitro tests concerning immunomodulatory effects should be done before these substances are used for therapy in clinically controlled studies.

Flow cytometric analysis of procalcitonin expression in human monocytes and granulocytes

Procalcitonin (PCT), a precursor of calcitonin is a useful indicator of severe systemic infection and sepsis. For a better understanding of the pathophysiological background of PCT induction, a study was made of the intracellular expression of PCT in various human white blood cell populations-i.e. monocytes and polymorphonuclear granulocytes (PMNs)-and the role of TNF-alpha in the stimulation of their PCT production. The expression of PCT was investigated by flow cytometric analysis with intracellular staining with antibodies to the PCT components calcitonin (CT) and katacalcin (KC). Both human peripheral monocytes and granulocytes expressed PCT, and increased intracellular amounts of the PCT components were demonstrated after stimulation with Staphylococcus aureus as TNF-alpha inducer. The S. aureus induced stimulation of PCT production was inhibited by anti-TNF-alpha monoclonal antibodies. The monocytic cell line U937 expressed considerable intracellular PCT, but S. aureus failed to induce an increase in PCT expression. The determination of intracellular PCT by flow cytometry is a promising and a sensitive method for further investigation of the effects of various cytokines and cytokine-inducing agents in PCT synthesis of human monocytes and granulocytes.

Identification and quantification of granulocytes in caecal mucosa and submucosa of chickens experimentally infected with Eimeria tenella and Salmonella enteritidis

1. Poultry granulocytes are not clearly distinguished from each other with haematoxylin-eosin (HE) stain; thus, histochemical techniques must be used. Three experiments were carried out using 4-week-old Leghorn chickens. 2. Three, 80-chicken groups were orally infected with (1) 10(8) colony forming units (CFUs) Salmonella enteritidis, or (2) 10(4) Eimeria tenella oocysts, or (3) 10(8) CFUs S. enteritidis + 10(4) E. tenella oocysts. Ten chickens from each group were euthanased and caecum samples obtained. Caecum samples were fixed in 10% formalin (buffered, pH 7.4) at 4, 8, 12 h, 1, 3, 5, 7, and 14 d post-inoculation (PI). 3. Samples were stained using three different staining techniques: HE for the identification of heterophils and eosinophils, Ziehl-Neelsen for mast cells, and p-phenilenediamine dihydrochloride plus pyrocatechol (PPD + PC) for eosinophils. 4. Birds from Experiment 1 showed no changes in the numbers of granulocytes. Birds from Experiments 2 and 3 showed higher numbers of heterophils in caecal mucosa and submucosa separately, on d 5 and 7. In Experiment 3, a decrease was observed in submucosal mast cells on d 3. Chickens from Experiments 2 and 3 showed increased numbers of mucosal mast cells between d 7 and 14. 5. PPD + PC positively stained eosinophils, but not heterophils. 6. Numbers of heterophils and mast cells were increased during the acute inflammatory process caused by E. tenella. Therefore, mast cells could play a role as primary inflammatory cells. Eosinophils seem not to be part of the inflammatory process caused by E. tenella.

Pharmacokinetics and pharmacodynamics of gatifloxacin against Streptococcus pneumoniae and Staphylococcus aureus in a granulocyte-rich exudate

The pharmacokinetics of gatifloxacin were assessed in serum and in skin blister fluid (SBF), as was the pharmacodynamic activity in SBF. Five hours after a single dose of gatifloxacin, SBF killed 2.5 logs of Streptococcus pneumoniae and 1.5 log of Staphylococcus aureus during a 2-h incubation ex vivo.

The mouse as a model for investigation of human granulocytic ehrlichiosis: current knowledge and future directions

The use of laboratory mice to investigate correlates of infectious disease, including infection kinetics, cellular alterations, cytokine profiles, and immune response in the context of an intact host has expanded exponentially in the last decade. A marked increase in the availability of transgenic mice and research tools developed specifically for the mouse parallels and enhances this research. Human granulocytic ehrlichiosis (HGE) is an emerging, zoonotic disease caused by tick-borne bacteria. The HGE agent (Anaplasma phagocytophila) is one of two recognized pathogens to cause human granulocytic ehrlichiosis (HGE). The mouse model of HGE complements in vitro tissue culture studies, limited in vivo large animal studies, and ex vivo studies of human and ruminant neutrophils, and promises new avenues to approach mechanisms of disease. In the overview reported here, we focus principally on current research into HGE pathogenesis using the mouse model. Included is a discussion of current changes in ehrlichial classification and nomenclature, a review of ehrlichial biology and ecology, and highlights of clinical disease in animals and people.

PCR detection of Borrelia burgdorferi sensu lato, tick-borne encephalitis virus, and the human granulocytic ehrlichiosis agent in Ixodes persulcatus ticks from Western Siberia, Russia

PCR assays were used to test adult Ixodes persulcatus ticks from Western Siberia, Russia, for Borrelia burgdorferi sensu lato, tick-borne encephalitis virus (TBEV), and the human granulocytic ehrlichiosis (HGE) agent. Of the 150 ticks that were studied, 38% were infected with B. burgdorferi, 46% were infected with TBEV, and 8% were infected with the HGE agent. These three pathogens were distributed in the ticks independently of one another.

Human granulocytic ehrlichiosis in a renal allograft recipient: review of the clinical spectrum of disease in solid organ transplant patients

BACKGROUND

Ehrlichiosis is a recently described zoonotic infection with two major expressions: human granulocytic ehrlichiosis (HGE) and human monocytic ehrlichiosis (HME). The organisms associated with HGE and HME have been detected in a tick vector in several regions of United States and cases of ehrlichiosis have been reported in the general population.

METHODS

We report a case of HGE in a renal allograft recipient and review the clinical spectrum of disease in solid organ transplant recipients and the epidemiological basis for risk.

RESULTS

Our patient demonstrated the typical epidemiological, clinical and laboratory features of human granulocytic ehrlichiosis and responded to treatment with doxycycline.

CONCLUSIONS

Human ehrlichiosis should be considered in the differential diagnosis of patients with solid organ transplants, who present with fever and thrombocytopenia. The incidence of ehrlichiosis in the solid organ transplant population is similar to that in the United States general population. As reported in immunocompetent patients, prompt diagnosis and treatment results in the rapid resolution of symptoms in transplanted individuals.

Granulocytic ehrlichiosis in Swedish dogs and horses

Granulocytic ehrlichiosis is a frequently diagnosed tick-borne disease in Swedish dogs and horses. The infection is caused by a granulocytic Ehrlichia species belonging to the Ehrlichia phagocytophila genogroup. In the acute stage, the disease is mainly characterized as a febrile illness and diagnosis can be confirmed by the demonstration of ehrlichial inclusions in blood granulocytes. Seropositivity in many healthy dogs and horses indicate that the infection also can be transient without clinical signs. The infection can persist in experimentally inoculated animals for months, but to what extent this persistance also occurs in naturally infected animals and is associated with clinical signs, is not clarified yet.

Seroprevalence of human granulocytic ehrlichiosis infection in Belgium

In order to determine the prevalence of human granulocytic ehrlichiosis (HGE) in Belgium, the sera of 216 patients previously diagnosed with Borrelia burgdorferi infection were analysed for possible coinfection with the agent of HGE. For this purpose, an indirect immunofluorescence assay was applied, and positive results were confirmed by Western blot using a 44-kilodalton recombinant protein (rP44) specific for the agent of HGE. Sixteen of the 216 (7.4%) sera tested were positive for the HGE agent using indirect immunofluorescence assay, and seven (3%) of them were confirmed positive by Western blot. These data suggest the agent for HGE is present in Belgium and may cause coinfection in patients infected with Borrelia burgdorferi, as has been reported in the USA and elsewhere in Europe. This is the first report documenting the identification of this agent in Belgium.

Human ehrlichioses

Human ehrlichioses represent one of the best examples of newly emergent infectious diseases in which the classic triad of host, infectious agent, and environment are intertwined closely. These pathogens have existed for eons on the planet, and some were described as veterinary pathogens decades ago. Because of dramatic increases of deer and small mammal populations in certain areas and the subsequent increased populations of particular blood-feeding ticks, the risk of developing these diseases is higher than before. Increasing human populations in suburban areas and increased immunosuppressed populations (transplant patients, human immunodeficiency virus patients, and cancer survivors) also have increased risk of developing severe forms of these diseases.

[Detection of the endotoxin of Gram-negative bacteria in human blood]

Recent new data on the important role played by lipopolysaccharides (endotoxin) of Gram negative bacteria in physiology and pathogenesis of the most important human infectious and noninfectious diseases testify to the necessity of wide clinical trials of different methods for LPS detection in blood and other physiological fluids. Among presently available diagnostic methods for endotoxinemia detection, the highly sensitive LAL (Limulus Amebocyte Lysate) test in various modifications is most widely used. The LAL test is known to be non-specific, however many drawbacks of this test have been successfully overcome. The results of clinical studies on the determination of the LPS activity in the systemic blood stream and antibody titers to its most common determinants, as well as the reserves of endotoxin binding with granulocytes give grounds for optimistic evaluation of the future studies on the role of LPS in human physiology and pathology. In clinical practice both positive sides and drawbacks of the presently known methods for LPS detection, including the LAL test, must be borne in mind for the complex evaluation of endotoxinemia levels.

In vitro and in vivo interactions of Haemophilus ducreyi with host phagocytes

We investigated the phagocytosis of Haemophilus ducreyi both in vitro and in vivo. Human granulocyte and monocyte phagocytosis of opsonized and nonopsonized, fluorescence-labeled H. ducreyi was assessed by flow cytometry. Both Escherichia coli and noncapsulated H. influenzae were included as controls. The maximal percentage of granulocytes taken up by H. ducreyi was 35% after 90 min. In contrast, 95% of H. influenzae bacteria were phagocytosed by granulocytes after 30 min. These results indicated that H. ducreyi phagocytosis was slow and inefficient. Bacterial opsonization by using specific antibodies increased the percentage of granulocytes phagocytosing H. ducreyi from 24 to 49%. The nonphagocytosed bacteria were completely resistant to phagocytosis even when reexposed to granulocytes, indicating that the H. ducreyi culture comprised a mixture of phenotypes. The intracellular survival of H. ducreyi in granulocytes, in monocytes/macrophages, and in a monocyte cell line (THP-1) was quantified after application of gentamicin treatment to kill extracellular bacteria. H. ducreyi survival within phagocytes was poor; approximately 11 and <0.1% of the added bacteria survived intracellularly after 2 and 20 h of incubation, respectively, while no intracellular H. influenzae bacteria were recovered after 2 h of incubation with phagocytes. The role of phagocytes in the development of skin lesions due to H. ducreyi was also studied in vivo. Mice that were depleted of granulocytes and/or monocytes and SCID mice, which lacked T and B cells, were injected intradermally with approximately 10(6) CFU of H. ducreyi. Within 4 days of inoculation, the granulocyte-depleted mice developed lesions that persisted throughout the experimental period. This result reinforces the importance of granulocytes in the early innate defense against H. ducreyi infection. In conclusion, H. ducreyi is insufficiently phagocytosed to achieve complete eradication of the bacteria. Indeed, H. ducreyi has the ability to survive intracellularly for short periods within phagocytic cells in vitro. Since granulocytes play a major role in the innate defense against H. ducreyi infection in vivo, bacterial resistance to phagocytosis probably plays a crucial role in the pathogenesis of chancroid.

Seroprevalence of human granulocytic ehrlichiosis in high-risk groups in Denmark

The aim of this study was to evaluate the seroprevalence of human granulocytic ehrlichiosis (HGE) among 300 residents in the county of Funen, Denmark. All of these people had either suspected or confirmed borreliosis. Two hundred control sera were included in the study. Samples were submitted by general practitioners and by hospital departments. An indirect immunofluorescence assay was used to identify sera reactive to HGE and an enzyme-linked immunosorbent assay was used to analyse Borrelia burgdorferi antibodies. There were 63 (21%) HGE-positive sera, 53 of which came from Borrelia-seropositive patients. Among patients with negative Borrelia serology, but with clinical suspicion of borreliosis, 14.3% were HGE-positive (n = 70). Of the 200 control sera, 3.5% were HGE-positive and 10.5% were Borrelia-positive. No HGE-positive samples were found among subjects < 20 y of age, wheras 20.4% of Borrelia seropositive samples where from subjects < 20 y of age. No mortality was observed in the HGE-positive group and the percentage of serum samples positive for both Borrelia and HGE did not differ significantly between hospitalized and non-hospitalized patients. Our study indicates that HGE infection with or without concomitant or previous Borrelia burgdorferi infection is common in tick-exposed individuals > 20 y old in the county of Funen, Denmark.

Lysosomal-cationic test and NBT reduction test just partially reflect the completeness of phagocytic process in human granulocytes

The results of NBT test correlated with the index of phagocytosis completeness in only 43% of 21 clinically healthy volunteers. The level of the lysosomal-cationic test was significantly reduced only if the phagocytosis completeness index was markedly decreased. The latter is an integral value reflecting the bactericidal activity of granulocytes.

The serological response of patients infected with the agent of human granulocytic ehrlichiosis

To characterize the serological response in humans to human granulocytic ehrlichiosis (HGE), we prospectively observed 152 patients for as long as 42 months. HGE was confirmed by detection of morulae in blood smears, polymerase chain reaction, blood culture, or a combination of these tests for 94 patients (62.3%), and 92 (97.8%) of the patients had specific serum antibodies thereafter. One hundred twenty-six (99.2%) of 127 patients tested at 1 month were seropositive (89 of 127 patients had seroconversion), and 150 (98.7%) of the 152 patients had become seropositive by 6 months. Eleven patients (7.3%) remained seropositive at 42 months. Neither antibiotic therapy initiated during the first week of illness nor preexisting immunosuppressive conditions abrogated a serological response. Indirect fluorescent antibody testing of acute-phase and convalescent-phase serum samples is a sensitive tool for laboratory confirmation of HGE.

The microbial receptor CEACAM3 is linked to the calprotectin complex in granulocytes

Engulfment of foreign pathogens is an evolutionary ancient host cell endocytic response. Signaling pathways effecting phagocytosis are divergent and largely depend on the structural features of the cell surface receptor utilized. CEACAM3, a member of the CD66 complex on human neutrophils, has been implicated as a cellular receptor promoting phagocytosis of microorganisms. The cytoplasmic domain of CEACAM3 (CEACAM3(cyt)) contains an immunoreceptor tyrosine-based activation motif. In this study we demonstrate that CEACAM3(cyt) is phosphorylated by protein kinase C, casein kinase I, and Src-kinase in vitro. To identify molecules binding to CEACAM3(cyt) in vivo, we used differentially phosphorylated recombinant expressed CEACAM cytoplasmic domains to isolate CEACAM3(cyt)-associated proteins from granulocyte extracts. Calprotectin, which modulates neutrophil integrin-mediated adhesion and leukocyte trafficking and displays antimicrobial activity, interacts specifically with CEACAM3(cyt). This interaction is calcium-modulated but independent of phosphorylation of CEACAM3(cyt). Although tyrosine-phosphorylated CEACAM3(cyt) binds and stimulates Src-kinases in vitro, no CEACAM3(cyt)-associated phosphokinase activity was copurified.

Western blot analysis of sera reactive to human monocytic ehrlichiosis and human granulocytic ehrlichiosis agents

Laboratory diagnosis of human ehrlichioses is routinely made by an indirect immunofluorescence assay (IFA) using cultured ehrlichia-infected whole cells as antigen. Concern has been raised that incorrect diagnoses of human monocytic ehrlichiosis (HME) or human granulocytic ehrlichiosis (HGE) may be made on the basis of serologic cross-reactivity between Ehrlichia chaffeensis and the agent of HGE. The present study examined whether two recombinant major outer membrane proteins, rP30 and rP44, that were previously shown to be sensitive and specific serodiagnostic antigens for HME and HGE, respectively, could be used to discriminate IFA dually reacting sera. Thirteen dually IFA-reactive sera, three sera that were IFA positive only with E. chaffeensis, and three sera that were IFA positive only with the HGE agent were examined by Western immunoblot analysis using purified whole organisms and recombinant proteins as antigens. All 16 E. chaffeensis IFA-positive sera reacted with rP30. However, none of these sera reacted with rP44, regardless of IFA reactivity with the HGE agent. The three HGE-agent-only IFA-positive sera reacted only with rP44, not with rP30. Western immunoblotting using purified E. chaffeensis and the HGE agent as antigens suggested that heat shock and other proteins, but not major outer membrane proteins, cross-react between the two organisms. Therefore, Western immunoblot analysis using rP44 and rP30 may be useful in discriminating dually HME and HGE IFA-reactive sera.

Uptake and killing of Listeria monocytogenes by normal human peripheral blood granulocytes and monocytes as measured by flow cytometry and cell sorting

Cellular components of innate immunity (NK cells, monocytes and granulocytes) play an important role in early resistance to Listeria monocytogenes in the mouse model. Minimally invasive methods of measuring the bacteriocidal capacity of these cells may be useful as a biomarker of susceptibility in humans. A technique was developed whereby the uptake and survival of L. monocytogenes could be measured in human granulocytes and monocytes using small volumes of peripheral blood. This method used flow cytometry to detect the presence of PKH-2-labeled bacteria within these cells. Survival of bacteria was determined by sorting of infected cells based on a combination of fluorescence and light scattering properties. Considerable variation in bacterial recovery was seen between normal volunteers. There was consistently greater survival of a fully virulent strain of L. monocytogenes within monocytes and granulocytes compared with an isogenic strain lacking the hemolysin, listeriolysin O, when measured at baseline. There was no evidence of longer-term bacterial survival or growth at 2 or 24 h. This technique may be useful for assessment of both host resistance and pathogen virulence.

Clinical and serological follow-up of patients with human granulocytic ehrlichiosis in Slovenia

An evaluation of the clinical outcome and the duration of the antibody response of patients with human granulocytic ehrlichiosis (HGE) was undertaken in Slovenia. Adult patients with a febrile illness occurring within 6 weeks of a tick bite were classified as having probable or confirmed HGE based on the outcome of serological or PCR testing. Thirty patients (median age, 44 years) were enrolled, and clinical evaluations and serum collection were undertaken at initial presentation and at 14 days, 6 to 8 weeks, and 3 to 4, 6, 12, 18, and 24 months. An indirect immunofluorescence assay (IFA) was performed, and reciprocal titers of > or =128 were interpreted as positive. Patients presented a median of 4 days after the onset of fever and were febrile for a median of 7.5 days; four (13.3%) received doxycycline. Seroconversion was observed in 3 of 30 (10.0%) patients, and 25 (83.3%) showed >4-fold change in antibody titer. PCR results were positive in 2 of 3 (66.7%) seronegative patients but in none of 27 seropositive patients at the first presentation. IFA antibody titers of > or =128 were found in 14 of 29 (48.3%), 17 of 30 (56.7%), 13 of 30 (43.4%), and 12 of 30 (40.0%) patients 6, 12, 18, and 24 months after presentation, respectively. Patients reporting additional tick bites during the study had significantly higher antibody titers at most time points during follow-up. No long-term clinical consequences were found during follow-up.

The value of in vitro cell culture of granulocytes in the detection of Ehrlichia

Peripheral blood leukocytes from different animals were isolated from whole blood and maintained in Dulbeco's medium containing homologous serum without antibiotics. After 72 hrs microscopic examination of these cells showed that most animals were infected with Ehrlichia. Observation of thin blood smears from the same animals showed that only two were positive for Ehrlichia. The results of this investigation show that leukocyte culture is superior to the traditional thin blood film method in the detection of Ehrlichia and that asymptomatic carriers are easily detected. The method is inexpensive and does not require specific cell lines although it is necessary to use sterile sera.

Immunopathology and ehrlichial propagation are regulated by interferon-gamma and interleukin-10 in a murine model of human granulocytic ehrlichiosis

Previous studies of human granulocytic ehrlichiosis (HGE) suggest a role for host immune response in resolving infection and in causing histopathological lesions. We hypothesize that interferon (IFN)-gamma allows tissue injury that is suppressed by interleukin (IL)-10 after initiation by ehrlichia infection. Thus, parental C57BL/6, IL-10-/-, and IFN-gamma-/- strains of mice were infected and then assayed for hepatic histopathological lesions, ehrlichial burden, and cytokine responses to ehrlichial antigen in primary splenic cultures during the first 21 days after infection. Histopathological severity in C57/BL6 and IL-10-/- mice rose in parallel through day 7, but then diverged as pathology in IL-10-/- mice continued to increase and remained high throughout the course of the study. The histopathological rank of C57BL/6 of mice decreased at day 10 and returned to baseline levels at days 14 and 21. In contrast, the IFN-gamma-/- strain had baseline pathology scores throughout the course of the infection, yet had significantly higher ehrlichial burden both in the blood and tissues than C57BL/6 or IL-10-/- mice. This suggests that histopathological lesions in the HGE murine model do not result from direct ehrlichia-mediated injury but from immunopathological mechanisms initiated by ehrlichial infection. The similarities with lesions in humans suggest an immunopathological basis for HGE.

Loss of virulence by heterophil-adapted Salmonella pullorum

We report that reduction of virulence for day-old chicks was achieved after eight-times-repeated heterophil passage of Salmonella pullorum (SP). The virulent source strain SP-V caused 64% mortality and 89% internal organ as well as 89% cecal colonization 10 days after administration of 10(7) colony-forming units (CFU) to day-old chicks. Eight-times-repeated passage of SP in heterophils resulted in attenuated strain SP-A that was nonlethal and reduced colonization of internal organs from 89% for SP-V strain to 4.3% for SP-A strain 10 days after administration of 10(7) or 10(8) CFU to day-old chicks. Cecal colonization was reduced from 89% for SP-V strain to 0 for SP-A strain 10 days after administration of 10(7) or 10(8) CFU to day-old chicks.

Comparison of heterophil phagocytosis for heterophil-adapted Salmonella enteritidis (HASE) and wild-type Salmonella enteritidis (SE)

Serial passage of Salmonella enteritidis (SE) yields heterophil-adapted SE (HASE) strains that have resulted in decreased shedding of SE in feces and reduced egg contamination. Additionally, increasing the number of heterophil passages further reduced the number and frequency of fecal shedding. To evaluate SE and heterophil interaction, nine SE strains were fluorescein isothiocyanate-labeled when viable. There were six wild-types: SE TK 474, SE TK 584, SE TK 599, SE TK 600, SE TK 655, and SE TK 657; and three HASE strains: TK 499 heterophil adapted five times, TK 598 heterophil adapted six times, and TK 605 heterophil adapted 11 times. Trials were repeated seven times in duplicate with heterophils isolated from seven healthy chickens. Heterophils were incubated with the bacterial strains at 41 C for 15 min, and 10,000 heterophils were analyzed by flow cytometry. Percentage of phagocytosis and mean channel number of fluorescence were compared. Both parameters were significantly increased for all HASE-type strains compared with wild-type, nonadapted SE strains. Increased phagocytosis of HASE bacterial strains may be significant in processing and elimination of the HASE strains and may be related to the protective effect of HASE by decreased shedding of wild-type SE challenge strains.

Human granulocytic ehrlichiosis presenting as facial diplegia in a 42-year-old woman

Neurologic manifestations of human ehrlichiosis are unusual and have been described almost exclusively in human monocytic ehrlichiosis associated with Ehrlichia chaffeensis. We report here a case of a previously healthy 42-year-old woman who developed bilateral facial nerve palsies in association with infection by the agent of human granulocytic ehrlichiosis (aoHGE). The diagnosis was made by specific polymerase chain reaction amplification of aoHGE sequences from samples of the patient's blood and cerebrospinal fluid (CSF), as well as propagation of aoHGE in culture of HL60 cells inoculated with the patient's CSF. To our knowledge, this is the first report directly demonstrating the presence of aoHGE in CSF, and it underscores the importance of considering HGE in patients presenting with a nonspecific febrile illness and unexplained neurologic manifestations. HGE should also be considered in the differential diagnosis of bilateral facial palsy-a rare occurrence.