A novel therapeutic strategy for mycoplasma infectious diseases

Galactocerebroside biosynthesis pathways of Mycoplasma species: an antigen triggering Guillain-Barré-Stohl syndrome

Infection by Mycoplasma pneumoniae has been identified as a preceding factor of Guillain-Barré-Stohl syndrome. The Guillain-Barré-Stohl syndrome is triggered by an immune reaction against the major glycolipids and it has been postulated that M. pneumoniae infection triggers this syndrome due to bacterial production of galactocerebroside. Here, we present an extensive comparison of 224 genome sequences from 104 Mycoplasma species to characterize the genetic determinants of galactocerebroside biosynthesis. Hidden Markov models were used to analyse glycosil transferases, leading to identification of a functional protein domain, termed M2000535 that appears in about a third of the studied genomes. This domain appears to be associated with a potential UDP-glucose epimerase, which converts UDP-glucose into UDP-galactose, a main substrate for the biosynthesis of galactocerebroside. These findings clarify the pathogenic mechanisms underlining the triggering of Guillain-Barré-Stohl syndrome by M. pneumoniae infections.

Outcome of an outpatient specialty clinic for chronic epipharyngitis

OBJECTIVE

In Japan, chronic epipharyngitis became a subject of interest in the 1960s and is currently garnering renewed attention. Previous studies have focused only on the similarities between the immunological characteristics of the tonsil and epipharynx and reported the efficacy of epipharyngeal abrasive therapy (EAT) in patients with IgA nephropathy. However, endoscopic findings of chronic epipharyngitis have not yet been fully evaluated, and. this study aimed to elucidate those findings.

METHODS

The study period was from November 2016 to October 2017. Two hundred and twelve new patients visited the specialty outpatient clinic for EAT. Age distribution and mean age of patients, sex, chief complaint, diagnosis at other departments and outcomes were retrospectively reviewed based on medical records. Band-limited light endoscopy was performed, and the findings were videotaped in 102 of the 212 new patients, who underwent endoscopic EAT for the first time.

RESULTS

The study included 32 men and 70 women with a mean age of 46.0 years (range, 22-83 years). The most common complaint was postnasal drip (42 patients), followed by pharyngeal pain (12 patients), and throat discomfort (11 patients). The outcomes of 74 patients who continued treatment until the last session were; complete cure in 48.6% of cases, marked improvement in 21.6%, improvement in 16.2%, and no change in 13.5%. Band-limited light endoscopic findings included black spots (73%), granular changes (76%), vessel truncations (92%), crust/mucus adhesion (54%), adenoidal hypertrophy (31%) and tonsil cysts (7%). With regard to the appearance of the mucous membranes, 48% patients had an ivory-like-colored mucous membrane, 72% had a green vascular network, and 89% had a dark red to reddish-brown appearance. Six to nine months' EAT remarkably improved their symptoms with resolution of the endoscopic findings in 86% of the patients.

CONCLUSION

Nasal endoscopy using band-limited light is useful for diagnosis and management of chronic epipharyngitis. We believe that this study not only provides information to help the diagnosis of chronic epipharyngitis but also contributes to treat sick patients suffering from chronic epipharyngitis.

Chemosynthetic homologues of Mycoplasma pneumoniae β-glycolipid antigens for the diagnosis of mycoplasma infectious diseases

Mycoplasma pneumoniae expresses β-glycolipids (β-GGLs) in cytoplasmic membranes, which possess a unique β(1 → 6)-linked disaccharide epitope, which has high potential in biochemical and medicinal applications. In the present study, a series of β-GGLs homologues with different acyl chains (C12, C14, C16, and C18) were prepared from a common precursor. An ELISA assay using an anti-(β-GGLs) monoclonal antibody indicated that the synthetic homologues with long acyl chains had greater diagnostic potential in the order C18 > C16 > C14 > C12. Toward a simultaneous detection of natural glycolipids by mass spectrometry (MS), a deuterium-labeled C16 homologue (β-GGL-C16-d₃) was prepared and applied as an internal standard for a high-resolution electrospray ionization MS (ESI-MS) analysis. The ESI-MS analysis was used to identify and quantify acyl homologues (C16/C16, C16/C18, and C18/C18) of β-GGL-C16 in cultured M. pneumoniae. A β-GGLs homologue with a 1,2-diacetyl group (C2) was also prepared as a "water soluble" glycolipid homologue and characterized by ¹H NMR spectroscopy. We envisage that each of these chemosynthetic homologues will provide promising approaches to solve medical and biological problems associated with mycoplasma infectious diseases (MIDs).