Spirochetal infections

Case Report: Leptospirosis Complicated by Persistent, Bilateral Sensorineural Hearing Loss

The clinical manifestations of leptospirosis range from mild to life-threatening and can impact on multiple organ systems. A wide array of neurological manifestations of leptospirosis have been reported, although the pathophysiology of neuroleptospirosis remains incompletely understood. We present a case of leptospirosis complicated by bilateral sensorineural deafness, with nodular meningitis demonstrated in the internal auditory meatus on magnetic resonance imaging. The patient was treated with doxycycline, ceftriaxone, systemic and topical steroids, and hyperbaric oxygen therapy, with modest, but incomplete, improvement.

Sexually Transmitted Infections in Pregnant Women: Integrating Screening and Treatment into Prenatal Care

Chlamydia, gonorrhea, and syphilis continue to be significant burdens to the health of pregnant women and their children despite easy and effective guidance for screening and treatment. Specific guidelines exist for screening for these infections as well as treatment and follow-up. In this article, we review the epidemiology of chlamydia, gonorrhea, and syphilis. Testing methodology is also reviewed as molecular-based techniques have replaced culture as the current gold standard tests of choice for chlamydia and gonorrhea. The nontreponemal and treponemal serologic diagnostic and screening approach to syphilis has undergone less change. Treatment for gonorrhea includes a one-time dose of parenteral ceftriaxone and oral azithromycin. This treatment regimen not only addresses the possible gonococcal resistance seen in recent years but also treats chlamydia, which may present similarly or co-infect the same patient. Syphilis treatment in both pregnant women and their infected neonates remains with penicillin G formulations. It is crucial to establish close follow-up evaluation for the pregnant woman infected with these sexually transmitted infections to ensure adequate treatment and help prevent perinatal spread of the infection.

The potential use of cholestyramine to reduce the risk of developing Clostridium difficile-associated diarrhoea in patients receiving long-term intravenous ceftriaxone

Intravenous pharmacotherapy with the third-generation cephalosporin ceftriaxone is unfortunately associated with a relatively high incidence of Clostridium difficile-associated diarrhoea. Cholestyramine (colestyramine) is an anion-binding resin which can bind luminal C.difficile toxin A (TcdA) and toxin B (TcdB) and which may be beneficial in the treatment of recurrent antibiotic-associated pseudomembranous colitis. We therefore hypothesised that concomitant oral cholestyramine might reduce the risk of C.difficile-associated diarrhoea in patients receiving long-term intravenous ceftriaxone. A pilot study was carried out in which it was found that only three out of 46 (6.5%) such patients being treated with 2 g ceftriaxone daily for Lyme borreliosis, who also received 4 g cholestyramine daily, developed C.difficile-associated diarrhoea. This is smaller than a published report of the incidence of this complication in six out of 26 (23.1%) patients following 1-3 days' treatment with 1 g intravenous ceftriaxone, but without oral cholestyramine (p=0.06). We therefore recommend that a larger, double-blind placebo-controlled trial be carried out to test this hypothesis.

Interaction of variable bacterial outer membrane lipoproteins with brain endothelium

Background

Previously we reported that the variable outer membrane lipoprotein Vsp1 from the relapsing fever spirochete Borrelia turicatae disseminates from blood to brain better than the closely related Vsp2 [1]. Here we studied the interaction between Vsp1 and Vsp2 with brain endothelium in more detail.

Methodology/Principal Findings

We compared Vsp1 to Vsp2 using human brain microvascular endothelial cell (HBMEC) association assays with aminoacid radiolabeled Vsp-expressing clones of recombinant Borrelia burgdorferi and lanthanide-labeled purified lipidated Vsp1 (LVsp1) and Vsp2 (LVsp2) and inoculations of the lanthanide-labeled proteins into mice. The results showed that heterologous expression of LVsp1 or LVsp2 in B. burgdorferi increased its association with HBMEC to a similar degree. Purified lanthanide-labeled lipidated Vsp1 (LVsp1) and LVsp2 by themselves were capable of associating with HBMEC. The association of LVsp1 with brain endothelium was time-dependent, saturable, and required the lipidation. The association of Vsp1 with HBMEC was inhibited by incubation at lower temperature or with excess unlabeled LVsp1 or LVsp2 but not with excess rVsp1 or mouse albumin or an anti Vsp1 monoclonal antibody. The association of LVsp2 with HBMEC and its movement from blood to brain parenchyma significantly increased in the presence of LVsp1.

Conclusions/Significance

Variable bacterial outer membrane lipoproteins interact with brain endothelium differently; the lipidation and variable features at the protein dome region are key modulators of this interaction.