A novel bacterial symbiont in the nematode Spirocerca lupi.
ABSTRACT BACKGROUND: The parasitic nematode Spirocerca lupi (Spirurida: Thelaziidae), the canine esophagealworm, is the causative agent of spirocercosis, a disease causing morbidity and mortality indogs. Spirocerca lupi has a complex life cycle, involving an obligatory coleopteranintermediate host (vector), an optional paratenic host, and a definitive canid host. Thediagnosis of spirocercosis is challenging, especially in the early disease stages, when adultworms and clinical signs are absent. Thus, alternative approaches are needed to promote earlydiagnosis. The interaction between nematodes and their bacterial symbionts has recentlybecome a focus of novel treatment regimens for other helminthic diseases. RESULTS: Using 16S rDNA-based molecular methods, here we found a novel bacterial symbiont in S.lupi that is closely related to Comamonas species (Brukholderiales: Comamonadaceae) of thebeta-proteobacteria. Its DNA was detected in eggs, larvae and adult stages of S. lupi. Usingfluorescent in situ hybridization technique, we localized Comamonas sp. to the gut epithelialcells of the nematode larvae. Specific PCR enabled the detection of this symbiont's DNA inblood obtained from dogs diagnosed with spirocercosis. CONCLUSIONS: The discovery of a new Comamonas sp. in S. lupi increase the complexity of the interactionsamong the organisms involved in this system, and may open innovative approaches fordiagnosis and control of spirocercosis in dogs.
Article: Improved diagnosis of low intensity Spirocerca lupi infection by the sugar flotation method.Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 08/1996; 8(3):400-1. · 1.21 Impact Factor
Article: Central (intraosseous) adenoid cystic carcinoma of the mandible: report of a case with periapical involvement.[show abstract] [hide abstract]
ABSTRACT: Primary intraosseous salivary gland tumors are rare, with mucopidermoid carcinoma being the most frequent histotype. The authors present a case of adenoid cystic carcinoma, located in the mandibular incisor region, associated with pain. Endodontic treatment resulted in increased pain and progressive mandibular expansion. An apicoectomy was conducted, and an intraosseous adenoid cystic carcinoma was diagnosed at histological examination. The patient was treated by wide surgical resection, and is alive and well without recurrences or distant metastases 14 yr after the original diagnosis. The case presented herein calls attention to the preoperative clinical diagnosis of periapical lesions. Radiologically, focal sclerosing osteitis, cementoblastoma, cementifying and ossifying fibroma, periapical cemental dysplasia, complex odontoma, and calcifying epithelial odontogenic tumor should be considered in the differential diagnosis. In addition the unusual occurrence of salivary gland tumors in intraosseous location stresses the importance of systematic histological examination of any tissue sample obtained after endodontic procedures.Journal of Endodontics 01/2001; 26(12):760-3. · 2.88 Impact Factor
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ABSTRACT: Developing axons are attracted to the CNS midline by Netrin proteins and other as yet unidentified signals. Netrin signals are transduced in part by Frazzled (Fra)/DCC receptors. Genetic analysis in Drosophila indicates that additional unidentified receptors are needed to mediate the attractive response to Netrin. Analysis of Bolwig's nerve reveals that Netrin mutants have a similar phenotype to Down Syndrome Cell Adhesion Molecule (Dscam) mutants. Netrin and Dscam mutants display dose sensitive interactions, suggesting that Dscam could act as a Netrin receptor. We show using cell overlay assays that Netrin binds to fly and vertebrate Dscam, and that Dscam binds Netrin with the same affinity as DCC. At the CNS midline, we find that Dscam and its paralog Dscam3 act redundantly to promote midline crossing. Simultaneous genetic knockout of the two Dscam genes and the Netrin receptor fra produces a midline crossing defect that is stronger than the removal of Netrin proteins, suggesting that Dscam proteins also function in a pathway parallel to Netrins. Additionally, overexpression of Dscam in axons that do not normally cross the midline is able to induce ectopic midline crossing, consistent with an attractive receptor function. Our results support the model that Dscam proteins function as attractive receptors for Netrin and also act in parallel to Frazzled/DCC. Furthermore, the results suggest that Dscam proteins have the ability to respond to multiple ligands and act as receptors for an unidentified midline attractive cue. These functions in axon guidance have implications for the pathogenesis of Down Syndrome.Development 11/2008; 135(23):3839-48. · 6.60 Impact Factor