Epidemiological characteristics of dogs with Lyme borreliosis in the province of Soria (Spain)

From the point of view of the human disease, dogs are the most important animal reservoir of Lyme borreliosis; therefore, they are used as sentinel animals. In order to know the epidemiological characteristics of dogs with antibodies against Borrelia burgdorferi, 146 canine sera samples collected during 1993–94 have been studied. The antibody detection was made by an indirect immunofluorescence method and confirmed by a haemagglutination test. Seventeen dogs (11.6%) were seropositive, of which seven were hunting dogs, three were shepherd dogs, five were domestic pets, one was a watchdog and one was a stray dog. Seven dogs had longhair phenotype, 2 medium length type, 4 hard-hair and the other 4 were short-haired. Twelve seropositive dogs were males and five were females. All seropositive dogs were more than 1 year old. The dogs with greater seroprevalence were those that harboured ticks more often than the rest. Spring and summer were the seasons when more ticks were observed. The seroprevalence found in dogs was similar to that previously obtained in humans in this area. This finding gave evidence to an intimate association between human and canine seroprevalence.     

Tick bite and Lyme borreliosis risk at a recreational site in England

The risk of tick bite and Lyme borreliosis in a forested area in England with public access was studied over a two-year period. Tick infestation levels were high with more than 1000 members of the public reporting for tick removal at a local clinic. Most of the attached ticks were nymphs (82%) and distinct differences in anatomical sites of attachment were observed in children and adults. Children sustained nymphal bites to the head, neck and axilla region much more frequently than adults (48 vs. 10%), whereas adults were bitten on the lower legs more frequently than children (46 vs. 9%). The vegetation was heavily infested with ticks and high numbers were particularly associated with areas used by deer. The average density of nymphs collected from the vegetation was 14.1 per 10 m²(range 5.1–43.6). Infection rates of these nymphs determined by PCR and indirect IFA ranged from 5.2–17.0%, and the genospeciesBorrelia valaisianaand B. gariniiwere detected, suggesting that birds may be important reservoir hosts in this area. It is estimated that, at the level of tick challenge observed here, at least 50 persons per year may be bitten by infected ticks at this site. However, no cases of Lyme borreliosis have been reported through the clinic follow-up procedure, and sera from 19 forest workers were negative for antibody to B. burgdorferisensu lato. Despite the high challenge from tick bites, this particular recreational forest site poses a low risk of infection to the general public, and prophylactic antibiotic treatment or serological testing following a bite is not justified.     

从粤东丰溪自然保护区台湾角血蜱体内分离出莱姆病螺旋体

目的：检测台湾角血蜱携带莱姆病螺旋体情况。方法：直接荧光抗体法（ＤＦＡ）和病原分离培养。结果：该蜱是粤东丰溪自然保护区优势蜱种，用采集的该蜱５０只取中肠涂片，ＤＦＡ检测８只为阳性，阳性率１６％；从１１５只（２３组）该蜱中分离出１株莱姆病螺旋体，命名为ＭＤ６。经单克隆抗体鉴定，结果与国内Ｍ７菌种反应相同。结论：从媒介蜱类分离出莱姆病螺旋体，在广东尚属首次，证实该地为莱姆病流行区     

Borrelia burgdorferi sigma54 is required for mammalian infection and vector transmission but not for tick colonization

Previous studies have shown that a sigma54-sigma(S) cascade regulates the expression of a few key lipoproteins in Borrelia burgdorferi, the agent of Lyme disease. Here, we demonstrate that these sigma factors, both together and independently, regulate a much more extensive number of genes and cellular processes. Microarray analyses of sigma54 and sigma(S) mutant strains identified 305 genes regulated by sigma54 and 145 regulated by sigma(S), whereas the sigma54-sigma(S) regulatory cascade appears to control 48 genes in B. burgdorferi. In silico analyses revealed that nearly 80% of genes with altered expression in the sigma54 mutant were linked to potential sigma54-dependent promoters. Many sigma54-regulated genes are expressed in vivo, and through genetic complementation of the mutant, we demonstrated that sigma54 was required by B. burgdorferi to infect mammals. Surprisingly, sigma54 mutants were able to infect Ixodes scapularis ticks and be maintained for at least 24 wk after infection, suggesting the sigma54-sigma(S) regulatory network was not involved in long-term survival in ticks. However, sigma54 mutants did not enter the salivary glands during tick feeding, indicating that sigma54-regulated genes were involved in the transmission process.     

PCR in lyme neuroborreliosis: a prospective study

OBJECTIVES: DNA proof is the only widely available direct diagnostic tool in Lyme borreliosis. Sensitive PCR detecting of spirochetal DNA was prepared and a prospective study in neuroborreliosis was performed. MATERIALS AND METHODS: 57 hospitalised patients with active neuroborreliosis and proved CSF antibodies synthesis were examined. Nested-PCR (utilizing three targets) was used for the detection of specific DNA in plasma, CSF and urine. RESULTS: Before treatment 36 positive patients (63.1%) were found in all tested specimens in parallel, 28 patients (49.1%) were positive in urine, 20 in CSF (35.0%) and 16 in plasma 28.0%). Later only urine was tested and the following results were obtained: 17 positive patients (30.0%) immediately after treatment, 8 (14.0%) after 3 months and one patient persisted positivity after 6 months. CONCLUSIONS: The highest sensitivity of PCR was achieved in the acute period of neuroborreliosis - 63.1% in three body fluids comparing with CSF antibody synthesis.     

Lyme disease of the brainstem

Lyme disease is a multisystem infectious disease caused by the tick-borne spirochete, Borrelia burgdorferi. Central nervous system (CNS) involvement typically causes local inflammation, most commonly meningitis, but rarely parenchymal brain involvement. We describe a patient who presented with clinical findings suggesting a brainstem process. Magnetic resonance imaging (MRI) and positron emission tomography (PET) suggested a brainstem neoplasm. Prior to biopsy, laboratory evaluation led to the diagnosis of Lyme disease. Clinical and imaging abnormalities improved markedly following antimicrobial therapy. We describe Lyme disease involvement of the cerebellar peduncles with hypermetabolism on PET. Although MRI is the primary imaging modality for most suspected CNS pathology, the practical applications of PET continue to expand.     

Persistent synovitis in children with Lyme arthritis: two unusual cases. An immunogenetic approach

We report on two patients with a persistent Lyme arthritis. In addition both had a peculiar disease history. The first patient had oligoarticular juvenile idiopathic arthritis in remission. Five months after an infected tick bite, she developed a relapse of arthritis in the same knee. We considered Lyme borreliosis as the possible trigger for this reactivation. The disease history of the second patient was that of a classical non-responder. After extensive antibiotic treatment osteolytic lesions became visible. MRI images suggested an erosive arthropathy and arthroscopy was used to investigate possible erosive arthritis. Studies on collected material made us consider the following hypothesis. Despite demonstration of a spirochete fragment in a synovial biopsy, the patient recovered without additional antibiotic treatment. Conclusion: delay of antibiotic treatment after appearance of erythema migrans may cause systemic spread of the antigen and predispose to Lyme arthritis. If intra-articular steroids are considered when spontaneous resolution of Lyme arthritis does not occur, magnetic resonance imaging of the affected joint, prior to administration, may provide additional information. The success of synovectomy may be related to removal of undegraded antigenic material which may prolong the inflammation.Abbreviations ELISA enzyme-linked immunosorbent assay - EM erythema migrans - JIA juvenile idiopathic arthritis - LA Lyme arthritis - LD Lyme disease - LIV Lyme index value     

Genomics-based identification of targets in pathogenic bacteria for potential therapeutic and diagnostic use

The availability of numerous complete microbial genome sequences has profoundly altered our understanding of a number of fundamental biological processes. For example the enzymes involved in aminoacyl-tRNA (AA-tRNA) synthesis, the key process responsible for the accuracy of protein synthesis, have been found to be highly species-specific. In particular, a number of pathogens contain certain pathways of AA-tRNA synthesis that are unrelated to those found in their mammalian hosts. Since AA-tRNA synthesis is indispensable for cell viability, the discovery of pathogen-specific pathways and enzymes presents novel therapeutic and diagnostic targets. Here we will review recent advances in the elucidation of AA-tRNA synthesis pathways and discuss the possible pharmaceutical exploitation of these discoveries. In particular, the integration of genomic and biochemical approaches to identify novel targets for the treatment of Chlamydial infections and the diagnosis and treatment of Lyme disease will be presented.     

In vitro dermal and transdermal delivery of doxycycline from ethanol/migliol 840 vehicles

This work investigated the feasibility of dermal and transdermal delivery of doxycycline from vehicles containing Migliol 840 (M840) and ethanol. Delivery of the drug via the skin would provide a useful alternative to oral delivery, which has many undesirable side-effects, such as oesophageal ulceration and disturbance of the normal gut flora. Potential applications include malaria prophylaxis, and the treatment of acne vulgaris, Lyme disease and Reiter syndrome. Experiments were performed to determine the permeation of doxycycline across excised full-thickness human skin and heat-separated epidermal membranes from saturated solutions in ethanol, 1:1 and 2:1 ethanol/M840. Unusual burst behaviour was observed using an ethanol vehicle, possibly as a result of the formation of dimers at saturation. Doxycycline permeated to a higher degree from ethanolic vehicles when M840 is present, suggesting that M840 is capable of enhancing the permeation of doxycycline. The flux across full-thickness skin was highest from a 2:1 ethanol:M840 vehicle (2.41 μg cm⁻² h⁻¹), sufficient to deliver 282 μg l⁻¹ using an area of application of 30 cm². The data also produced unexpected results in that permeability across heat separated skin was an order of magnitude greater than across full-thickness skin (28.75 μg cm⁻² h⁻¹ for the 2:1 ethanol:M840 vehicle). Depth profiling indicated that the drug distributed quite evenly throughout the epidermis. The mean amount of doxycycline recovered from the epidermis at the end of a permeation experiment was 458.4 μg ml⁻¹. This was far higher than the volume of extractable lipid present in the same unit area, approximately 52.3 μg ml⁻¹ and indicated that a large proportion of the drug must have been located within the proteinaceous domain. The data therefore suggest (1) significant amounts of doxycycline can be administered into and across the skin; (2) M840 is a potentially useful enhancing vehicle; and (3) the transcellular route was of significance.     

Persistence of borrelial DNA in the joints of Borrelia burgdorferi‐infected mice after ceftriaxone treatment

Yrjänäinen H, Hytönen J, Hartiala P, Oksi J, Viljanen MK. Persistence of borrelial DNA in the joints of Borrelia burgdorferi‐infected mice after ceftriaxone treatment. APMIS 2010; 118: 665–73. We have earlier shown that Borrelia burgdorferi‐infected and ceftriaxone‐treated mice have viable spirochetes in their body, since immunosuppressive treatment allows B. burgdorferi to be detected by culture. However, the niche of the persisting spirochetes remained unknown. In the present study, we analyzed the tissues of B. burgdorferi‐infected and ceftriaxone‐treated mice by culture and PCR to reveal the foci of persisting spirochetes. C3H/HeN mice were infected via intradermal needle injection with B. burgdorferi s.s. N40. The mice were treated as follows: (i) short (5 days) and (ii) long (18 days) course of ceftriaxone at 2 weeks of infection and killed after either 10 or 30 weeks, or (iii) the mice received ceftriaxone for 5 days at 18 weeks of infection and were killed 21 weeks after the treatment. All samples of ceftriaxone‐treated mice were culture negative, whereas all untreated controls were culture positive. Importantly, B. burgdorferi DNA was detected in the joints of 30–100% of the treated mice. In conclusion, these results combined with earlier results suggest that the joint or a tissue adjacent to the joint is the niche of persisting B. burgdorferi in ceftriaxone‐treated mice.