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PloS One 2018Rhodococcus equi is one of the most important causes of disease in foals. Infection is typically characterized by pyogranulomatous pneumonia although extrapulmonary...
Rhodococcus equi is one of the most important causes of disease in foals. Infection is typically characterized by pyogranulomatous pneumonia although extrapulmonary infections occur occasionally. Uveitis and polysynovitis have been reported in foals naturally infected with R. equi and are thought to be the result of an immune-mediated process. However, the pathogenesis of these conditions is poorly understood. The objectives of this study were to document the occurrence of uveitis and polysynovitis after experimental infection with R. equi and to determine if these disorders are the direct result of infection at these sites. Foals between 3 and 4 weeks of age were infected intratracheally with virulent R. equi using inocula of 1×108 CFU (high inoculum; n = 16) or 1×107 CFU (low inoculum; n = 12). Foals were monitored twice daily and necropsy was performed 14 days post-infection. Aqueous humor and synovial fluid were collected aseptically and the percentage of affected lung was calculated. The mean (± SD) percentage of affected lung was significantly higher with the high inoculum (31.8 ± 14.6%) than with the low inoculum (14.4 ± 11.4%). Fourteen of 25 foals developed uveitis and 20 of 28 foals developed polysynovitis. R. equi was cultured from the aqueous humor of 11 foals and from the synovial fluid of 14 foals. The risk of development of polysynovitis and protein concentration in the aqueous humor were significantly higher in foals that received the high inoculum. These results indicate that polysynovitis and uveitis are septic complications associated with the severity of lung disease.
Topics: Actinomycetales Infections; Animals; Horse Diseases; Horses; Pneumonia, Bacterial; Rhodococcus equi; Sepsis; Synovitis; Uveitis; Virulence
PubMed: 29415076
DOI: 10.1371/journal.pone.0192655 -
Indian Journal of Ophthalmology 1984
Topics: Actinomycetales Infections; Adult; Dacryocystitis; Humans; Male; Streptomyces
PubMed: 6519735
DOI: No ID Found -
Clinical Microbiology and Infection :... May 2004As recent external quality control results have shown, the diagnosis of Rothia dentocariosa infection still presents problems for clinical laboratories. This review... (Review)
Review
As recent external quality control results have shown, the diagnosis of Rothia dentocariosa infection still presents problems for clinical laboratories. This review describes the taxonomy, as well as the chemotaxonomic, morphological and biochemical characteristics, of this organism, and surveys bacteria that may be confused with Rothia dentocariosa.
Topics: Actinomycetales Infections; Bacteriological Techniques; Diagnosis, Differential; Humans; Micrococcaceae; Phylogeny
PubMed: 15113315
DOI: 10.1111/j.1469-0691.2004.00784.x -
Veterinary Microbiology Jun 1997Rhodococcal pneumonia is an important, life threatening disease of foals and immunosuppressed humans. Increased knowledge of the mechanisms of protective immunity are... (Review)
Review
Rhodococcal pneumonia is an important, life threatening disease of foals and immunosuppressed humans. Increased knowledge of the mechanisms of protective immunity are required in order to develop an effective immunoprophylaxis strategy for horses and immunotherapeutic regiments for people. Both humoral and cellular components of the immune system may be involved in immune clearance of R. equi. The susceptibility of foals less than 4-6 months of age is postulated to reflect waning maternal antibody, and passive transfer of hyperimmune plasma can provide protection on endemic farms. However, effective clearance is likely to require appropriate cellular responses, including the secretion of cytokines. In murine models, both CD4+ and CD8+ T lymphocytes can reduce bacterial counts in the lung. CD4+ cells appear to be both required and sufficient, and IFN-gamma is a primary mediator. Clearance appears to be a type 1 immune response while type 2 responses may lead to a failure to clear and lesion development. It remains to be determined how the cellular immunity experiments reported in mice relate to horses and humans. Likewise, the role of specific R. equi antigens in protective immunity has not been determined.
Topics: Actinomycetales Infections; Animals; Antibody Formation; Disease Susceptibility; Female; Horse Diseases; Horses; Humans; Immunity, Cellular; Immunity, Maternally-Acquired; Mice; Pregnancy; Rhodococcus equi
PubMed: 9226832
DOI: 10.1016/s0378-1135(97)00086-2 -
Emerging Infectious Diseases Mar 2022To help clarify the clinical manifestations, diagnosis, and treatment for Whipple disease, we report a case of a man in China infected with Tropheryma whipplei. The...
To help clarify the clinical manifestations, diagnosis, and treatment for Whipple disease, we report a case of a man in China infected with Tropheryma whipplei. The patient had multiple subcutaneous nodules as the only manifestation, which was not consistent with the typical symptoms of T. whipplei infection.
Topics: Actinomycetales Infections; China; Humans; Male; Skin Neoplasms; Tropheryma; Whipple Disease
PubMed: 35202530
DOI: 10.3201/eid2803.211989 -
Journal of Clinical Microbiology Aug 2022
Review
Topics: Actinomycetales Infections; Anti-Bacterial Agents; Humans; Tropheryma; Whipple Disease
PubMed: 35975989
DOI: 10.1128/jcm.01595-21 -
Postgraduate Medical Journal Nov 1999
Topics: Actinomycetales; Actinomycetales Infections; Female; Foot Bones; Foot Diseases; Humans; Middle Aged; Radiography
PubMed: 10621878
DOI: 10.1136/pgmj.75.889.671 -
Microbiology Spectrum Jun 2022A previously reported method for evaluating the intracellular growth of Rhodococcus equi using enhanced green fluorescent protein is unsuitable for the quantitative...
A previously reported method for evaluating the intracellular growth of Rhodococcus equi using enhanced green fluorescent protein is unsuitable for the quantitative evaluation of the entire sample because the signal can be detected only in the excitation region. Therefore, we created an autobioluminescent using luciferase (). First, we connected to the functional promoter P and introduced it into the chromosomes of ATCC33701 and ATCC33701_P-. Luminescence was detected in both transformants, and a correlation between the bacterial number and luminescence intensity in the logarithmic phase was observed, indicating that is functionally and quantitatively expressed in . The luminescence of ATCC33701 was significantly higher than that of ATCC33701_P- at 24 h after infection with J774A.1. Next, RNA-Seq analysis of ATCC33701 to search for endogenous high-expression promoters resulted in the upstream sequences of RS29370, RS41760, and being selected as candidates. Luminescence was detected in each transformant expressing the using these upstream sequences. We examined the luminescence intensity by coexpressing the gene, an enhancer of the luciferase reaction, with . The luminescence intensity of the coexpressing transformant was significantly enhanced in J774A.1 compared with the non-coexpressing transformant. Finally, we examined the luminescence . The luminescence signals in the organs peaked on the third day following the administration of ATCC33701 derivatives in mice, but no luminescence signal was detected when the ATCC33701_P- derivative was administered. The autologous bioluminescent method described herein will enhance the and quantitative analysis of proliferation. We established an autologous bioluminescent strain of and a method to evaluate its proliferation and quantitatively. This method overcomes the weakness of the fluorescence detection system that only measures the site of excitation light irradiation. It is expected to be used as an and growth evaluation method with excellent quantitative properties. In addition, it was suggested that the selection of a promoter that expresses could produce a luminescence with high intensity. Although this method needs further improvement, such as creating transformants that can maintain high luminescence intensity regardless of environmental changes such as temperature fluctuations, it is possible to observe bacterial growth over time in mice without killing them. Therefore, this method can be used to not only evaluate the pathogenicity of various wild and gene-deficient strains but also to screen preventive and therapeutic methods such as vaccines.
Topics: Actinomycetales Infections; Animals; Bacterial Proteins; Mice; Rhodococcus equi; Virulence Factors
PubMed: 35638814
DOI: 10.1128/spectrum.00758-22 -
Journal of Clinical Microbiology Apr 2011Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a... (Review)
Review
Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a case of Gordonia bronchialis bacteremia and pleural space infection in the absence of an indwelling intravascular catheter and review the breadth of reported infections with this emerging pathogen.
Topics: Actinomycetales; Actinomycetales Infections; Bacteremia; Blood; DNA, Bacterial; DNA, Ribosomal; Female; Humans; Microscopy; Middle Aged; Molecular Sequence Data; Pleurisy; RNA, Ribosomal, 16S; Radiography, Thoracic; Sequence Analysis, DNA; Tomography, X-Ray Computed
PubMed: 21270217
DOI: 10.1128/JCM.02121-10 -
Microbes and Infection May 2012The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic organisms, exhibiting filamentous branching structures... (Review)
Review
The order Actinomycetales includes phylogenetically diverse but morphologically similar aerobic and anaerobic organisms, exhibiting filamentous branching structures which fragment into rods or coccoid forms. Lung pathogens of the order comprise Mycobacterium, Nocardia, Corynebacterium, Actinomyces, Kytococcus, Rothia, Williamsia, as well as Gordonia, Tsukamurella and Rhodococcus. Particularly, members of the last three genera are uncommon aerobic agents of lung cavitations and tuberculosis(TB)-like syndromes, that should be carefully considered in the aetiology of parenchymal lesions. Correct identification of such organisms is hard to obtain, but is crucial to provide patients with adequate diagnose and treatment. Then, this review aims to unearth their airway tropism, as well as their clinical impact as agents of lung disease.
Topics: Actinomycetales; Actinomycetales Infections; Humans; Pneumonia, Bacterial
PubMed: 22192786
DOI: 10.1016/j.micinf.2011.11.014