Humoral immune response in dogs naturally infected with Borrelia burgdorferi sensu lato and in dogs after immunization with a Borrelia vaccine.

Lyme arthritis in dogs can be induced under experimental and natural conditions. However, the veterinary relevance of canine borreliosis is still under extensive investigation. The prevalence of symptoms is clearly low, although the risk of tick exposure is high. Current research focuses on case definitions, methods for diagnosing clinical disease in dogs, and discrimination between an immune response to a natural infection and an immune response to vaccination. In this experimental study, 23 dogs raised under tick-free conditions were allocated to two groups. The 11 dogs in the first group were vaccinated with a commercial borrelia vaccine and subsequently developed detectable antibody titers. The 12 dogs in the second group were walked on two consecutive days in an area where ticks were endemic. On day 5 after exposure, engorged ticks were removed from the 12 dogs and were analyzed for Borrelia DNA by a real-time PCR assay. Blood samples were taken before exposure/vaccination and at defined time points thereafter. Antibody responses were evaluated using an immunofluorescence antibody test (IFAT) and Western blotting. Seven dogs from which Borrelia-positive ticks were removed seroconverted and developed individual immune responses. Blood and urine samples taken from the tick-exposed group at weeks 1 and 3 for real-time PCR analysis and culture were always negative for bacterial DNA. In conclusion, despite serological evidence of infection/immunization, no clinical signs of disease were observed. The antibody patterns in a single Western blot did not permit differentiation between the different antigen sources (vaccine versus natural infection). However, repeated Western blot analyses may be useful for the confirmation of infection or vaccination status, since the time courses of the levels of specific antibodies seem to be different.

Impact of a pertussis booster vaccination program in adolescents and adults on the epidemiology of pertussis in Austria.

BACKGROUND: A resurgence of pertussis has been observed in several countries; however, inconsistent data are available for Europe. In Austria, routine pertussis vaccination for babies is administered at 3, 4, and 5 months, and in the second year of life. Since 2002, regular boosters for all persons >6 years of age (including adults) are recommended. This study was undertaken to analyze epidemiologic trends of laboratory-reported pertussis to evaluate current vaccination strategy in Austria. METHODS: Epidemiologic surveillance of laboratory-reported pertussis was conducted from January 1, 2000, to December 31, 2005. Infection was confirmed by positive serology, by positive culture of Bordetella pertussis, or by detection of sequences of the pertussis toxin gene by real-time polymerase chain reaction (RT-PCR). Data were assessed by age, hospitalization rate, seasonality, and incidence rate. RESULTS: During the observation period 4395 reported cases of pertussis were eligible for analysis. The mean annual incidence increased from 6.4 per 100,000 population in 2000 to 11.1 cases per 100,000 population in 2005. Incidence rates were highest among children less than 1 year of age. Decreasing rates were observed for children and adolescents <16 years of age, whereas increasing rates were detected for persons 16 years of age and older. The mean age of reported pertussis cases increased from 30 years (+/-25.9 SD) in 2000 to approximately 44 years (+/-23.7 SD) in 2005. Hospitalization rates were highest in infants <6 months (86%) and lowest in those 10 to <50 years of age (17%), followed by an increase to 80% in persons 85 years of age and older. In general, no seasonal occurrence of disease was apparent. CONCLUSIONS: Pertussis incidence remains high among adults implying that coverage rates regarding booster vaccinations for adolescents and adults still are too low. Reinforced application of the current booster strategy is needed.

Seasonal variations in detecting Borrelia burgdorferi sensu lato in rodents from north eastern Austria.

Austria is well known as an endemic area of Lyme borreliosis. To assess the annual variation of rodent populations that may host agents of Lyme borreliosis we collected rodents in northeastern Austria. Life traps were set out every six weeks during a year consecutively in one each of the three different zones (Hohenau, Ernstbrunn, Vienna Woods) that cover the main habitat characteristics of small mammals in northeastern Austria. Rodents were collected and identified. Samples of heart, urine bladder and brain were removed under aseptic conditions for cultivation of borrelia. Samples of heart muscle were additionally used for molecular detection of borrelia by Real-Time polymerase chain reaction. PCR was performed with borrelia universal primers and with species-specific primers. 938 mice were caught, most frequently Apodemus flavicollis (44%), followed by Clethrionomys glareolus (35%), Microtus arvalis (9%), A. sylvaticus (7%) and Mus musculus (6%). Significant differences were seen in the total number of catch per area (Hohenau, Ernstbrunn, Vienna Woods equal 10:9:2) and in the distribution of the various rodent species in the respective areas. Borrelia strains were grown from only 65 (7%) animals, and more frequently isolated from bladder wall than from heart muscle, and only once from brain. Heart specimens of 223 animals were positive by borrelia PCR (24%), most frequently of the rodent species A. flavicollis (43%) and C. glareolus (38%). Borrelia afzelii was most frequently identified, followed by B. burgdorferi sensu stricto, B. garinii and by mixed infection of B. afzelii with B. burgdorferi sensu stricto. B. garinii was most frequently detected in heart samples of A. sylvaticus (about 20%). In about 3% of PCR positive samples the identification of one of the three mentioned genospecies of borrelia could not be ascertained with the test panel used. The results confirm the rodent species A. flavicollis, A. sylvaticus, M. arvalis and C. glareolus as reservoir animals for B. afzelii, B. garinii and B. burgdorferi sensu stricto, agents of Lyme borreliosis. Notable is the salient presence of B. garinii in heart specimens of A. sylvaticus.

Detection of Mycoplasma pneumoniae in serum specimens from patients with mycoplasma pneumonia by PCR.

There are few data on detection of Mycoplasma pneumoniae from blood, serum or plasma, and systematic studies on this diagnostic approach in community-acquired pneumonia (CAP) are scarce. Compared to testing respiratory specimens, this approach has the advantages that it is less dependent on proper specimen collection, serum is easily stored and handled, and the pathogen is detected in a primary sterile site, where colonization can be ruled out. In this study, acute-phase serum specimens from 29 patients of Vienna University Hospital (treated between 11/1994 and 6/2004; female: 14, male: 15; median age: 31 years, range: 15-66 years) with CAP and serologically verified M. pneumoniae infection, who had not received anti-mycoplasma therapy prior to serum collection, were tested for M. pneumoniae by conventional PCR and real-time PCR. Conventional PCR yielded negative results for all specimens, but real-time PCR detected M. pneumoniae in 15/29 patient sera (52%). These findings indicate that M. pneumoniae is present in the bloodstream of a substantial proportion of patients with mycoplasma pneumonia. Despite the possible adherence of M. pneumoniae to human erythrocytes, the pathogen can be detected from serum, if a method with enhanced sensitivity is applied. However, the negative predictive value of PCR from serum with regard to etiological diagnosis is low. With regard to the potential clinical benefit of blood-based PCR diagnosis of mycoplasma pneumonia the diagnostic accuracy of this approach using either serum or whole-blood specimens should be addressed by large-scale studies.

Emergence of lyme arthritis after autologous chondrocyte transplantation.

We report herein the first known incidence of the emergence of borrelial arthritis following autologous chondrocyte transplantation for repair of a cartilage defect. The patient had no recent manifestation of Lyme borreliosis, but 15 years earlier had had an expanding erythematous lesion after a tick bite. The current infection resulted in massive joint swelling, elevated body temperature, dissemination of the graft, and transplant failure. Results of routine bacteriologic studies were negative. A diagnosis of Lyme arthritis was first considered following the detection of Borrelia-specific serum antibodies. Additional evidence was provided when borrelial DNA sequences were detected in the synovial fluid through polymerase chain reaction. The diagnosis was confirmed by culture of Borrelia burgdorferi from the synovial fluid. The possibility of a dormant borrelial infection should be considered in patients who undergo repair of cartilage defects with autologous chondrocyte transplantation. We recommend that synovial fluid and joint tissue be screened for the presence of viable Borrelia before transplantation of an autologous graft.

Chlamydia pneumoniae in central retinal artery occlusion.

PURPOSE: There is increasing evidence that the common respiratory human pathogen Chlamydia pneumoniae has a causative role in atherosclerosis. We investigated the association of this pathogen with acute central retinal artery occlusion (CRAO). PATIENTS AND METHODS: Sera of 14 consecutive patients with CRAO and of 14 age- and sex-matched control subjects were examined. Antibodies against chlamydial lipopolysaccharide (LPS) and outer membrane proteins of C. pneumoniae were determined by an enzyme-linked immunosorbent assay (ELISA). RESULTS: In the CRAO group, seven patients (50%) were found to be IgA positive, 12 (86%) were IgG positive and one (7%) was IgM positive for chlamydial LPS antibodies. In the control group 36%, 79% and 14% were IgA, IgG and IgM positive, respectively. The results showed no significant difference between the groups. In the CRAO group, IgA, IgG and IgM antibodies to C. pneumoniae were found in 43%, 79% and 0% of subjects, respectively. These findings did not differ significantly from those pertaining to matched controls. CONCLUSIONS: These data do not support an association between acute CRAO and current C. pneumoniae infection.

Prevalence of coinfection with Francisella tularensis in reservoir animals of Borrelia burgdorferi sensu lato.

INTRODUCTION AND PURPOSE: Studies on Lyme borreliosis and other tick-borne zoonoses in the Austrian and Slovakian borderland, a region endemic for tularemia, revealed a relatively high prevalence of infection with Borrelia burgdorferi s.l. and Francisella tularensis in small terrestrial mammals, as well as in the ticks, during a one-year survey. The occurrence of coinfection with the agents of Lyme borreliosis and tularemia was assessed in different species of rodents. METHODS: Organs of small mammals, live-trapped mostly in six-week intervals from May 1994 to April 1995, were cultured on appropriate media in order to grow borreliae and F. tularensis. RESULTS: Infection with B. burgdorferi s.l. and also with F. tularensis was found in all the most abundant rodent species. A significant difference was observed in the time period of isolation of these agents. Borrelia was cultured from May to January (PCR detected borrelia up to April), while F. tularensis was isolated from August to December. Coinfection was seen in two species of voles, Clethrionomys glareolus trapped in August and Microtus arvalis in October. The Borrelia strains isolated from these animals were identified as B. garinii. Isolates of F. tularensis belonged to the subspecies holarctica, biovar II. CONCLUSIONS: Results obtained indicate that in endemic regions for tularemia the prevalence of infection with borreliae could be modified in different animal species mainly during epizootic outbreaks of tularemia.

Horses and Borrelia: immunoblot patterns with five Borrelia burgdorferi sensu lato strains and sera from horses of various stud farms in Austria and from the Spanish Riding School in Vienna.

Grazing animals are continuously exposed to tick bites. Consequently, one may expect that horses will become infected with the various pathogens carried by ticks including Borrelia burgdorferi sensu lato. Whether horses may develop clinical disease due to this pathogen is controversially discussed. We were interested to learn about the infection of horses with Borrelia burgdorferi sensu lato within one season by studying the dynamics of the humoral immune response in paired blood samples. The majority of horses examined were Lipizzaner from the stud farm in Piber/Steiermark, and from the Spanish Riding School in Vienna. Smaller groups of animals of different breeds were from stud farms in Kärnten, Niederösterreich, Salzburg and Steiermark. Clinical status and medical history were obtained and blood was drawn at the beginning of the highest tick activity and nine months later in 1998. Immunoblot technique (Western blot) was used in order to determine the dynamics in the immune response patterns. As antigens served the genospecies Borrelia afzelii, Borrelia burgdorferi sensu stricto, Borrelia garinii, Borrelia lusitaniae, and Borrelia valaisiana. 309 horses (age median 7 years, range 1/12 to 33 years) were seen at the first round. 186 of these animals (60.2%; median age 6 years, range 4/12 to 33 years) were re-examined in the second round. All animals were in normal health condition during both rounds of examination and blood sampling. Analysis of the immunoblot patterns was based on in-house-, Pko-, Pka2-, Pbi-, and European Union Concerted Action on Lyme Borreliosis (EUCALB) 2 & 3-criteria; analyses revealed a variety of positive results with different strains and criteria. Positive immunoblot results with 186 paired samples and B. afzelii as antigen, for example, ranged from 52 to about 91% in the first, and 53 to 93% in the second round. The age dependency analyses showed that the first infection with B. burgdorferi sensu lato occurs in the first year. Re-infection is characterised by appearance of additional bands. Continuously tick-exposed horses show a stable pattern of bands whilst in unexposed horses the number of bands decreases with age. In this study horses became repeatedly infected with B. burgdorferi sensu lato but, apparently, developed only rarely, if at all, clinical diseases. The infectious agent is predominantly B. afzelii. Antibodies to other borrelia genospecies are predominantly due to cross reactivity.

Anti chlamydia antibodies in patients with thoracic and abdominal aortic aneurysms.

BACKGROUND: Chlamydia species are suspected of being involved in the pathogenesis and progression of aortic aneurysms. We investigated serum levels of Chlamydia antibodies in patients with thoracic aortic aneurysms (TAA) and abdominal aortic aneurysms (AAA) compared to levels in healthy individuals. METHODS: We included 35 consecutive patients with TAA, 42 patients with AAA and 42 age- and sex-matched healthy controls in a case control study. Serum antibodies (IgM and IgG) against Chlamydia lipopolysaccharide (LPS), Chlamydia pneumoniae and Chlamydia trachomatis were measured by recombinant ELISA and quantified by measurement of optical density. RESULTS: Patients with TAA exhibited median immunoglobulin levels against Chlamydia LPS (IgM 0.090, IgG 0.266), C. pneumoniae (IgM 0.023, IgG 0.264) and C. trachomatis (IgG 0.247) comparable to those of healthy subjects [Chlamydia LPS IgM 0.209 (p = 0.1), IgG 0.301 (p = 0.2); C. pneumoniae IgM 0.051 (p = 0.07), IgG 0.516 (p = 0.1); C. trachomatis IgG 0.153 (p = 0.2)]. Patients with AAA had higher serum levels of IgG against Chlamydia LPS (0.560) compared to healthy individuals [0.301 (p = 0.04)], but no significant elevation of antibodies against C. pneumoniae [IgM 0.029 (p = 0.1), IgG 0.545 (p = 0.9)] and C. trachomatis [IgG 0.219 (p = 0.3)]. CONCLUSION: Thoracic aortic aneurysms were not associated with signs of Chlamydia infection or immunopathogenicity. In contrast, patients with abdominal aortic aneurysms exhibited elevated levels of immunoglobulin against Chlamydia LPS, reflecting an unspecific Chlamydia immunopathogenicity. However, elevated levels of antibodies against distinct Chlamydia species were also not found in AAA patients.