IgG and IgA response to Simkania negevensis in sera of patients with respiratory and gastrointestinal symptoms.
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The presence of IgG and IgA antibodies to Simkania negevensis in adult Italian patients with respiratory or gastrointestinal symptoms was investigated by the microimmunofluorescence test. In patients with respiratory infections, IgG (50%) and IgA (13%) seropositivity was consistent with previous data. In patients with gastrointestinal disorders, IgG (68%) and IgA (18%) seroprevalence was significantly higher than in healthy controls. These results, in association with the previously described detection of S. negevensis in water sources, could suggest an oral route of infection other than droplets or close contact, and a possible association of S. negevensis with gastrointestinal infections. (+info)
Metabolic features of Protochlamydia amoebophila elementary bodies--a link between activity and infectivity in Chlamydiae.
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Epitheliocystis infection in cultured white sturgeon (Acipenser transmontanus): antigenic and ultrastructural similarities of the causative agent to the chlamydiae.
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A mild to moderate branchial epitheliocystis infection was diagnosed in subyearling (11 months old, 250-300 g) white sturgeon (Acipenser transmontanus) from a private culture facility with a 4-8% mortality in the population. Infected branchial epithelial cells contained the coccoid to coccobacillary epitheliocystis organisms, which appeared as cytoplasmic inclusions composed of a fine, homogeneous, dense, basophilic, granular material. The infected cells were variably enlarged with spherical to oval profiles and were randomly distributed throughout the branchial epithelium. The cytoplasmic inclusions stained positive with Macchiavello stain but negative with Brown and Brenn, periodic acid-Schiff, and Gimenez stains. Expression of chlamydial antigen was demonstrated within the cytoplasmic inclusions using a standard peroxidase-antiperoxidase immunohistochemical technique. Three stages of coordinated intracellular development were recognized by electron microscopy. The reticulate bodies were oval to spherical and 0.4-0.8 x 0.5-1.4 microns but often exhibited a pleomorphic and convoluted appearance because of variable membrane invaginations and evaginations suggestive of uneven fission and budding. Separate host cells contained intermediate bodies that were spherical to oval and 0.2-0.4 x 0.3-0.6 microns although often observed in the process of apparent uneven division. The presence of a cap or plaque composed of hexagonally arrayed fibrillar surface projections was initially recognized in this stage. A homogeneous population of 0.3-0.4 microns oval elementary bodies were observed separately in individual host cells. This developmental stage had a single, dense, compact, eccentrically located cytoplasmic condensation that occurred opposite to the location of the cap of hexagonally arrayed fibrillar surface projections. Morphologic characteristics of the epitheliocystis organism in these white sturgeon were similar to those previously described in other teleosts and expands the species catalogue of epitheliocystis infection. Furthermore, the ultrastructural similarities to the chalmydiae and the immunohistochemical detection of chlamydial antigen provides further evidence that the epitheliocystis agent is related to members of the Chlamydiales. Although the infection was considered mild to moderate and could not be definitively attributed to the mortality in this population, the potential adverse impact of epitheliocystis infection on sturgeon culture should be considered especially in intensive fish culture operations. (+info)
Rapid detection of the Chlamydiaceae and other families in the order Chlamydiales: three PCR tests.
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Few identification methods will rapidly or specifically detect all bacteria in the order Chlamydiales, family Chlamydiaceae. In this study, three PCR tests based on sequence data from over 48 chlamydial strains were developed for identification of these bacteria. Two tests exclusively recognized the Chlamydiaceae: a multiplex test targeting the ompA gene and the rRNA intergenic spacer and a TaqMan test targeting the 23S ribosomal DNA. The multiplex test was able to detect as few as 200 inclusion-forming units (IFU), while the TaqMan test could detect 2 IFU. The amplicons produced in these tests ranged from 132 to 320 bp in length. The third test, targeting the 23S rRNA gene, produced a 600-bp amplicon from strains belonging to several families in the order Chlamydiales. Direct sequence analysis of this amplicon has facilitated the identification of new chlamydial strains. These three tests permit ready identification of chlamydiae for diagnostic and epidemiologic study. The specificity of these tests indicates that they might also be used to identify chlamydiae without culture or isolation. (+info)