Hamster and Murine Models of Severe Destructive Lyme Arthritis

Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology

Use of optical mapping to sort uropathogenic Escherichia coli strains into distinct subgroups

Optical maps were generated for 33 uropathogenic Escherichia coli (UPEC) isolates. For individual genomes, the NcoI restriction fragments aligned into a unique chromosome map for each individual isolate, which was then compared with the in silico restriction maps of all of the sequenced E. coli and Shigella strains. All of the UPEC isolates clustered separately from the Shigella strains as well as the laboratory and enterohaemorrhagic E. coli strains. Moreover, the individual strains appeared to cluster into distinct subgroups based on the dendrogram analyses. Phylogenetic grouping of these 33 strains showed that 32/33 were the B2 subgroup and 1/33 was subgroup A. To further characterize the similarities and differences among the 33 isolates, pathogenicity island (PAI), haemolysin and virulence gene comparisons were performed. A strong correlation was observed between individual subgroups and virulence factor genes as well as haemolysis activity. Furthermore, there was considerable conservation of sequenced-strain PAIs in the specific subgroups. Strains with different antibiotic-resistance patterns also appeared to sort into separate subgroups. Thus, the optical maps distinguished the UPEC strains from other E. coli strains and further subdivided the strains into distinct subgroups. This optical mapping procedure holds promise as an alternative way to subgroup all E. coli strains, including those involved in infections outside of the intestinal tract and epidemic strains with distinct patterns of antibiotic resistance

Microbial mercury resistance and potential methylation rates in the Upper Wisconsin River

Microbial mercury resistance and potential mercury methylation rates were examined in water, sediment-floc, and sediment cores from the Upper Wisconsin River. Mercury (II) resistance was quantified using aerobic and anaerobic heterotrophic media containing 0-75 Hg/ml pg+2. Methylation activity was determined by measuring CH32O3Hg+ formation from 203Hg(N03)2. Sediment incubations were carried out under strict anaerobic conditions. Aerobic and anaerobic heterotrophic bacteria were highly resistant to 14 pg/ml Hg+2. Anaerobic heterotrophic bacteria were more resistant to higher concentrations of Hg+2 than aerobic heterotrophic bacteria. Mercury methylation activity was near background in the water, highest in surface sediments, and decreased with increasing sediment depth. More than 98% of the added 203Hg was bound to sediments within 4 hrs of inoculation, while more than 3% was methylated during a 10-day incubation. As much as 7% of the added 203Hg was methylated in other experiments. This suggests that bound Hg+2 was available for methylation. Organical1y enriched sediments exhibited higher methylation actiity than less eutrophic sediments. The addition of peptone to sediments caused highly significant (p < 0.01) increases in methylation activity, while vitamin B12 and sewage sludge caused significant (p < 0.05) increases. The presence of oxygen in sediments inhibited methylation activity. This indicates that mercury methylation in the Upper Wisconsin River is primarily an anaerobic process. The optimum temperature for methylation was 35degreesC, although the maximum in situ temperature was 24degreesC. A seasona1 summer peak in methylation activity was observed in water, f1oc, and sediments. These data suggest that the Upper Wisconsin River sediments have the potential to release large amounts of toxic methylmercury to the overlying water

Borreliacidal OspC Antibodies Specific for a Highly Conserved Epitope Are Immunodominant in Human Lyme Disease and Do Not Occur in Mice or Hamsters

Humans produce highly specific borreliacidal antibodies against outer surface protein C (OspC) shortly after infection with Borrelia burgdorferi sensu stricto. We previously demonstrated the epitope recognized by immunoglobulin M (IgM) and IgG OspC borreliacidal antibodies was located within the 50 amino acids nearest the carboxy (C) terminus. In this study, we show the immunodominant epitope is located in the highly conserved region within the seven C-terminal amino acids. Six early Lyme disease sera that contained borreliacidal activity and IgM and/or IgG OspC antibodies were chosen randomly and adsorbed with truncated OspC containing the 16 or 7 amino acids nearest the C terminus. Adsorptions with each truncated protein abrogated the borreliacidal activity completely. In addition, only small concentrations of OspC antibodies remained detectable by enzyme-linked immunosorbent assay and Western blotting. Moreover, borreliacidal OspC antibodies were not induced in laboratory mice or hamsters despite heavy infections with B. burgdorferi spirochetes. These findings confirm that borreliacidal antibodies comprise the majority of the IgM and IgG OspC antibody response in human Lyme disease and that the epitope is located in the highly conserved C terminus. In addition, rodent animal models appear to be inappropriate subjects for assessing the effectiveness of the epitope for serodiagnosis or as a human Lyme disease vaccine

C-Terminal Region of Outer Surface Protein C Binds Borreliacidal Antibodies in Sera from Patients with Lyme Disease

Borreliacidal antibodies specific for outer surface protein C (OspC) are induced shortly after infection with Borrelia burgdorferi. In this study, we identified the region of OspC recognized by immunoglobulin M (IgM) and IgG borreliacidal antibodies. Sera from patients with early Lyme disease were screened for borreliacidal activity specific for B. burgdorferi 50772 and OspC antibodies. Seven sera that contained similarly high titers of each response were then chosen randomly and adsorbed with OspC or a truncated OspC (OspC-Dra) containing the 50 amino acids nearest the carboxy terminus. Adsorption with OspC or OspC-Dra completely eliminated the borreliacidal activity in six (86%) of seven sera and significantly decreased the activity in the remaining serum (titer of 10,240 to 1,280). Moreover, OspC antibodies were no longer detected by OspC enzyme-linked immunosorbent assay or in a Western blot that contained native OspC. The findings confirmed that sera from patients with early Lyme disease contain high concentrations of IgM or IgG borreliacidal antibodies that bind a conserved region of OspC

Reassessment of a Midwestern Lyme Disease Focus for Borrelia burgdorferi and the Human Granulocytic Ehrlichiosis Agent

Previous studies from the late 1980s defined the risk of human Lyme disease by determining the prevalence of Borrelia burgdorferi infection in Ixodes scapularis ticks and Peromyscus sp. mice captured from areas around La Crosse, Wis. High percentages of B. burgdorferi-infected I. scapularis ticks and P. leucopus mice were common in areas located north of Interstate 90 but were not detected in areas south of this major east-west thoroughfare. In this study, we reevaluated the extent of B. burgdorferi infection. High percentages of mice captured from sites north of the interstate were still infected with B. burgdorferi. In addition, B. burgdorferi was recovered from 12 (67%) of 18 mice captured from a site well south of the highway. However, none of 104 mice or 713 I. scapularis ticks captured from the study sites were infected with Ehrlichia spp. The results confirmed the continued high risk for humans to contract infection with B. burgdorferi and the significant southward expansion of the area in which Lyme disease is endemic. In contrast, the risk of acquiring human granulocytic ehrlichiosis remains minimal despite the abundance of appropriate vector ticks and reservoir rodents

Borrelia miyamotoi Infection in Patients from Upper Midwestern United States, 2014–2015

We confirmed Borrelia miyamotoi infection in 7 patients who had contracted an illness while near La Crosse, Wisconsin, USA, an area where Ixodes scapularis ticks are endemic. B. miyamatoi infection should now be considered among differential diagnoses for patients from the midwestern United States who have signs and symptoms suggestive of tickborne illness

High Prevalence of Genital Mycoplasmas among Sexually Active Young Adults with Urethritis or Cervicitis Symptoms in La Crosse, Wisconsin

Sexually active young adults in the small college town of La Crosse, Wisconsin, were evaluated for conventional sexually transmitted pathogens and tested for infections with mycoplasmas. The prevalence in 65 symptomatic men or women and 137 healthy volunteers (67 men and 70 women) was compared. Urine specimens from both cohorts were tested by ligase chain reaction for Chlamydia trachomatis or Neisseria gonorrhoeae. In addition, the urethral or cervical swabs from the symptomatic subjects were tested by PCR for Mycoplasma genitalium and cultured for Mycoplasma hominis and the ureaplasmas. The results confirmed a relatively low prevalence of gonorrhea among symptomatic men (12%) and chlamydia among symptomatic men (15%) and normal women (3%). In contrast, infections with mycoplasmas, especially the ureaplasmas (57%), were common and the organisms were the only potential sexually transmitted pathogen detected in 40 (62%) symptomatic subjects. Because of the high prevalence, we also evaluated urethral swabs from an additional 25 normal female volunteers and recovered ureaplasmas from 4 (16%) subjects. Additionally, the participants rarely used protection during sexual intercourse and some symptomatic subjects apparently acquired their infections despite using condoms regularly. The findings demonstrate a strong association between abnormal urogenital findings and detection of myoplasmas, particularly ureaplasmas, and suggest the infections will remain common