An estimated 300,000 people contract Lyme disease in the USA every year, 10-20% of whom will experience long-term symptoms even after antibiotic treatment. These patients are said to have Chronic Lyme Disease (CLD). However, diagnostic guidelines, treatment protocols, and the etiological existence of CLD have been the subject of much controversy in the biomedical field, leading to negative mental and physical health outcomes for of patients with CLD. Patient support networks focused on illness experience, known as biosocialities, have formed in response to this controversy. CLD biosocialities create opportunities for patients to participate in biomedical activism and the scientific research process. A historical precedent for biosocial impact on biomedical knowledge and improved health outcomes has been established from patient activists with HIV/AIDS, breast cancer, and PTSD. The impact of CLD patients’ biosocial activism on a scientific and sociological level is evaluated through an examination of the publications of CLD support networks and biomedical research publications. CLD biosocial activism has resulted in more patient-centered research endeavours, etiological proof of CLD, improved diagnostic technologies, and new treatment protocols. These biomedical results have implications for improved CLD patient health outcomes and credibility for CLD as a legitimate disease on a biological and sociological level.

In Europe, Lyme disease is caused by the species Borrelia (B.) burgdorferi sensu stricto, B. garinii and B. afzelii. The disease is the most common vector-borne infection in Europe and the United States, and the resulting manifestation can involve the skin, nervous system, heart and joints. The symptoms that arise are associated with the Borrelia species causing the infection. The species most associated with neuroborreliosis is B. garinii whilst B. burgdorferi sensu stricto is associated with arthritis and B. afzelii is associated with dermatological symptoms. Lyme disease normally has three phases in untreated patients. The first phase is characterised by erythema migrans, a reddening of the skin around the area of the tick bite. If the disease develops to the second phase the patient will suffer from neuroborreliosis which is characterised by neurological symptoms such as headache and peripheral facial paralysis. Cerebrospinal fluid (CSF) analysis is used to diagnose neuroborreliosis. The diagnosis is complicated by variations between the different Borrelia species and that many healthy individuals have antibodies directed against Borrelia. Antibodies in CSF can be found in different diseases. The antibodies can be produced in the central nervous system or come across the blood-brain barrier and thus derive originally from the blood. By measuring the concentration of total albumin in serum and in CSF it can be determined if the antibodies present in the CSF have been produced in the central nervous system or if they originate from the blood. The typical manifestation in the last phase of Lyme disease is severe arthritis. The aim of this examination project was to compare two ELISAs for detection of antibodies directed to Borrelia. Indirect ELISAs from DAKO and Euroimmun were compared for the diagnosis of neuroborreliosis in 100 individuals. Borrelia specific antibodies of class IgM or IgG were found in 16 of 100 patients by DAKO’s ELISA and in 20 of the same 100 patients by Euroimmun’s ELISA. The reason that Euroimmun’s method detected more cases of neuroborreliosis is probably that this method detects antibodies directed to all three pathological species of Borrelia while DAKO’s method only detects antibodies directed to B. burgdorferi. In conclusion, this study indicates that Euroimmun’s method to detect antibodies of class IgM and IgG directed to Borrelia is superior to DAKO’s method. The obtained results were confirmed by Western blot analysis which gave results in accordance with those of Euroimmun’s ELISA.

Borrelia burgdorferi is a pathogenic spirochete which cycles between its arthropod vector and vertebrate host. If transmitted to humans, B. burgdorferi causes Lyme disease, an infection which can impair different organs, such as the skin, joints, nervous system and heart. Alterations in protein expression due to the different environments Borrelia encounters during its complicated life cycle require advanced adaptation mechanisms. The outer surface-exposed proteins play a critical role in survival and pathogenesis of Borrelia in different hosts and tissues, being involved in avoiding the host immune response, adhesion to different tissues and nutrient acquisition. This thesis aimed to characterize integral outer membrane proteins which play a role in solute and nutrient uptake, and provides support for their role in the environmental adaptation of Borrelia. In this thesis, three B. burgdorferi proteins, P13, BBA01 and P66, were shown to be porins, and characterized structurally and functionally using a combination of biochemical, biophysical and genetic methods. The channel-forming function of the 13 kDa protein, P13, was elucidated by a lipid bilayer assay. Post-translational processing of P13 occurred at the C-terminus by C-terminal processing protease (CtpA)-dependent cleavage. The membrane-spanning architecture of P13 was determined by epitope mapping and computer-based structural predictions which revealed that P13 is an unusual porin, not possessing the structural properties of conventional porins: rather than forming β-barrels, it is predicted to span the membrane with hydrophobic α-helices. p13 belongs to a paralogous gene family. The transcription of p13 and other gene family members during in vitro growth and in a mouse infection model was therefore investigated. The paralog BBA01, which has the highest sequence homology to P13, is expressed during in vitro growth in all three Lyme disease causing species, although at very low levels. Like P13, BBA01 is also processed by CtpA and exhibits very similar channel-forming activity. Furthermore, in the absence of P13, a proportion of total BBA01 protein is relocated to the bacterial surface with strong indications that BBA01 and P13 are functionally interchangeable. P66, an integrin binding protein, was also determined to be a porin. The oligomeric state of native P66, elucidated by chemical cross-linking, indicated that P66 forms trimers, as do the majority of conventional porins. Electron crystallography and a projection map of P66 crystals at 2.2 nm resolution revealed tetragonal unit cell symmetry with the area intercalated between the assembled protein structures consistent with the approximate expected size of the channel formed by P66. Finally, the biological relevance of two porins, P13 and P66, was demonstrated in a double mutant displaying a stress response as revealed by increased sensitivity to high osmolarity and elevated expression of the B. burgdorferi heat-shock protein HtrA homolog.

The incidence of tick-borne zoonoses such as Ehrlichiosis, Rocky Mountain Spotted Fever, and Lyme disease has steadily increased in the southeastern United States in recent years. According to the Centers for Disease Control and Prevention (CDC), the southeastern states accounted for 1,200 of the 27,000 total cases of Lyme disease reported in the U.S. in 2007. Although Ixodes scapularis is the most commonly recognized vector for the Lyme disease spirochete Borrelia burgdorferi, Dermacentor variabilis (a common vector for Rocky Mountain Spotted Fever) also has been shown to be a viable host for this pathogen. The purpose of the present study was to use PCR and DNA sequencing technologies to determine if Borrelia burgdorferi sensu lato is present in ticks and whole blood samples removed from raccoons and opossums trapped in south-central Kentucky. Raccoons and opossums were trapped in Barren and Warren counties of Kentucky between June 2007 and June 2008. Ticks were removed and stored in 70% ethanol. Sterile blood samples were collected into three 10 ml tubes containing the anticoagulant K2EDTA and stored at 4°C. Genomic DNA was extracted from ticks and blood samples using a QIAamp DNA mini kit and a QIAamp DNA blood mini kit (Qiagen) respectively. DNA samples were analyzed by polymerase chain reaction (PCR) for the presence of B. burgdorferi using oligonucleotide primers specific for the OspA gene. A total of 976 ticks were collected. Three different species were obtained from raccoons; Dermacentor variabilis, Amblyomma americanum, and Ixodes sp. Dermacentor variabilis was the only tick species found on opossums. Twenty-five percent (163/642) of the tick DNA samples were positive for Borrelia burgdorferi. Prevalence of B. burgdorferi by tick species was 24.4% (141/577) in D. variabilis, 40.6% (13/32) in A. americanum, and 27.6% (8/29) in I. scapularis. In the present study, 15.7% (8/51) of the total raccoon blood samples examined by PCR were positive for B. burgdorferi, while no opossum blood samples were positive. The high prevalence of B. burgdorferi in ticks common to raccoons and opossums observed in this study, as well as in a tick species that aggressively bites humans in the southeast U. S. (A. americanum), creates concern that there are ample opportunities for people to come in contact with the infected ticks on these animals. Future studies are urgently needed to fully assess the presence and prevalence of B. burgdorferi in Kentucky and other southeastern states in the U. S.

Medicinsk entomologi

A cell's ability to sense and respond to mechanical signals highlights the significance of physical forces in biology; however, to date most biomedical research has focused on genetics and biochemical signaling. We sought to further understand the physical mechanisms that guide the cellular migrations that occur in a number of biological processes, such as tissue development and regeneration, bacterial infections and cancer metastasis. We investigated the migration of single cells and determined whether the biomechanics of these cells could be used to elucidate multi-cellular mechanisms. We first studied Borrelia burgdorferi (Bb), the bacterium that causes Lyme disease. We created a mathematical model based on the mechanical interactions between the flagella and cell body that explained the rotation and undulation of the cell body that occurs as the bacterium swims. This model further predicts how the swimming dynamics could be affected by alterations in flagellar or cell wall stiffnesses. Fitting the model to experimental data allowed us to calculate the flagellar torque and drag for Bb, and showed that Treponema pallidum (Tp), the syphilis pathogen, is biomechanically similar to Bb. Next, we used experimentally-determined parameters of Bb's motility to develop a population-level model that accounts for the morphology and spreading of the "bulls-eye" rash that is typically the first indicator of Lyme disease. This work supported clinical findings on the efficacy of antibiotic treatment regimes. Finally, we investigated the dynamics of epithelial monolayers. We found that intracellular contractile stress is the primary driving force behind collective dynamics in epithelial layers, a result previously predicted from a biophysical model. Taken together, these findings identify the relevance of physics in cellular migration and a role of mechanical signaling in biomedical science.

The objectives of this study were to determine the distribution of Borrelia burgdorferi (Bb), the bacterium that causes Lyme disease, and its tick vector (Ixodes scapularis) in the Thousand Islands in Ontario, and to assess the effects of various factors, including host populations, temperature, and vegetation, on the distribution of Bb and ticks in this new endemic region. Data were collected via drag sampling and small mammal trapping at 12 sites and multimodel inference was used to evaluate variables. There was inter-island variation in the abundance of ticks and prevalence of Bb in ticks. Important predictors of tick numbers and infection prevalence included deer abundance, distance to the United States, temperature, species richness, and relative mouse abundance. These results will contribute to management strategies to reduce Lyme disease risk in the Thousand Islands and to our understanding of the effects of biodiversity on disease risk. / Canadian Cooperative Wildlife Health Centre; Ontario Ministry of Natural Resources; Parks Canada; Public Health Agency of Canada; Ontario Graduate Scholarship

No description available.

Borrelia burgdorferi s. l. is a spirochete which causes the multisystemic disorder Lyme disease. As the borreliae lack toxin production, the pathogenicity is thought to involve, at least in part, molecules from the outer surface. Most Lyme disease Borrelia strains express two major outer surface lipoproteins, OspA (31 kD) and OspB (34 kD), on their surface. However, some strains lack the expression of OspA and OspB, but express a smaller 21 to 25 kD OspC protein instead. This thesis focuses on the importance of these proteins in the pathogenesis of Lyme disease. Biochemical and immunochemical studies of the OspA and OspB proteins from strains of various geographic origins show considerable differences in the apparent molecular weights and in their reactivities to monoclonal antibodies. The cloning and sequencing of the ospAB opérons from strains of different origins has demonstrated that the heterogeneity is found also at the DNA level Comparison of the ospAB sequences allows the classification of the strains into three types, which coincide with the recent species designations, B. burgdorferi sensu stricto, B. afzelii and B. garinii The genes are located on a linear plasmid about 50 kb in size, and are cotranscribed as a single message. The expression of the osp operon in different strains was studied by Western blot and Northern blot analysis. The ospAB operon of strains expressing varying amounts of the Osp proteins was cloned and sequenced. The DNA sequence was found to be &gt;99% identical. The regulation appears to be primarily at the transcriptional level. In patients who have received incomplete treatment, B. burgdorferi have been isolated several years after the onset of the disease. As mentioned above, the ospAB loci of different strains show considerable heterogeneity, and it has been speculated that the spirochetes evade the host’s immune system by antigenic variation of the Osp proteins. In a mouse model system it was shown that no variation of the osp genes occurs over the course of an infection, and that other escape mechanisms must be used. The OspB proteins in particular have been shown to be very heterogeneous in different isolates. The MAb 84C recognizes a wide variety of B. burgdorferi strains, and the binding epitope was mapped to a conserved region in the carboxyl terminus of the OspB protein with putative structural and/or functional importance. It is well known that antibodies can kill bacteria in the presence of complement and phagocytes. Some antibodies seem to have a bactericidal effect by themselves. H6831 is a monoclonal antibody recognizing the OspB protein of some B. burgdorferi strains. The bactericidal action of univalent FAb fragments from H6831 was further characterized, and the binding epitope was mapped to a very heterogeneous region of the carboxyl end of the OspB protein. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser</p> / digitalisering@umu

Lyme disease is a multisystemic, infectious disease caused by the tick-borne spirochete Borrelia burgdorferi. The CDC designated LD as a reportable disease in 1990 and evidence suggests underreporting of the disease in Indiana. Local health department nurses have a major role in the areas of disease recognition, reporting, and education about LD. The present study assessed local health department nurses' knowledge of LD to determine their competence as LD educators.The study consisted of 428 nurses in 92 counties and three cities with independent health departments who were mailed a questionnaire containing 30 multiple-choice and/or true/false questions. Twenty-four nurses participated in a pilot study to establish the reliability of the instrument.The results were: (1) nurses did not differ in knowledge regardless of their duties, (2) urban and rural counties did not differ in knowledge, (3) experience did not make a difference in knowledge, and (4) less educated nurses were more knowledgeable. The nurses were least knowledgeable about LD reporting criteria, late stage symptoms, and and description of EM and most knowledgeable about prevention. The following are some of the recommendations suggested: more research with nurses on vector- borne diseases, better dissemination of information from CDC and ISDH, inservice programs for nursing personnel, and educational materials to distribute to the public. / School of Nursing