Virulence of Rhodococcus equi for mice.

Nakazawa, Muneo; Haritani, Makoto; Sugimoto, Chihiro; Isayama, Y

doi:10.1292/jvms1939.45.679

Cited by 25 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nakazawa et al (13) reported the virulence of R. equi for mice and the phagocytosis of four strains of R. equi by cultured murine peritoneal macrophages. They found that there was a significant difference between virulent and less virulent strains in the growth of R. equi in the spleens of intravenously inoculated mice, but not in the rates of phagocytosis (13). Although the strains used differed among these studies, the fate of the bacteria in mice was almost the same except for the rates of phagocytosis by the macrophages.…”

Section: Discussionmentioning

confidence: 99%

Correlation of In Vitro Properties of Rhodococcus (Corynebacterium) equi with Virulence for Mice

Takaı̈

Michizoe

Matsumura

et al. 1985

Microbiology and Immunology

View full text Add to dashboard Cite

To study the virulence of Rhodococcus (Corynebacterium) equi, seven ATCC strains of different serotypes were tested for their LD50 in mice, clearance of the organism from the lungs and spleen following intravenous or intratracheal inoculation, and in vitro interaction with murine peritoneal macrophages. Strains ATCC 33704 and 33705 were virulent for mice and multiplied in the lungs and spleen, resulting in death of the animal in 5 days. The other five strains were avirulent for mice. The number of bacteria in the lungs and spleen of mice given these five strains decreased immediately. Pulmonary clearance of strains ATCC 33703, 33706, and 33707 was significantly more rapid than that of the virulent strains ATCC 33704 and 33705 12 hr after inoculation. Complete clearance of the avirulent strain ATCC 33707 occurred by day 14, while that of virulent ATCC 33704 and 33705 strains occurred by day 30. The virulent strains ATCC 33704 and 33705 were resistant not only to phagocytosis but also to intracellular killing by macrophages. Strains ATCC 33702 and 33706 were rapidly killed by macrophages although they were rather resistant to phagocytosis. Strain ATCC 33703 was easily phagocytized though resistant to killing by macrophages. The most avirulent strains, ATCC 33707 and 6939, were easily phagocytized and rapidly killed by macrophages. These results indicate that virulence appeared to be related to the ability of the organisms to resist clearance from the lungs and spleen and to resist phagocytosis and intracellular killing by macrophages.

show abstract

Section: Discussionmentioning

confidence: 99%

Correlation of In Vitro Properties of Rhodococcus (Corynebacterium) equi with Virulence for Mice

Takaı̈

Michizoe

Matsumura

et al. 1985

Microbiology and Immunology

View full text Add to dashboard Cite

show abstract

“…The type strain does not cause pneumonia in foals (371,575) and is avirulent in mice (409,577). The virulence of R equi isolates for mice infected intravenously is related to the ability of the isolates to resist clearance from the liver and spleen by resisting phagocytosis and intracellular killing by mouse macrophages (409,577).…”

Section: Pathogenicity Studiesmentioning

confidence: 99%

The medically important aerobic actinomycetes: epidemiology and microbiology

1994

View full text Add to dashboard Cite

The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes.

show abstract

“…Alveolar macrophages from immunized normal (BALB/c) mice were least effective in killing N. asteroides when compared with macrophages isolated from liver, the peritoneal cavity, and the spleen (9). In studies of mice infected by R. equi by the intravenous, intranasal, or intratracheal route normal mice without genetically defined defects in immune function were used (16,116,165).…”

Section: Natural Infections In Other Speciesmentioning

confidence: 99%

“…The type strain isolated by Magnusson (ATCC 6939, NCTC 1621) does not cause pneumonia in foals (100,163) and is avirulent for mice (116,165). Lethality of strains for mice infected intravenously was related to the ability of organisms to resist both clearance from the liver and spleen and phagocytosis and intracellular killing by mouse macrophages (116,165). Based on data from experimental infections, clinical isolates are more pathogenic than environmental isolates (16,52).…”

Section: Natural Infections In Other Speciesmentioning

confidence: 99%

Rhodococcus equi: an animal and human pathogen

1991

View full text Add to dashboard Cite

Recent isolations of Rhodococcus equi from cavitatory pulmonary disease in patients with AIDS have aroused interest among medical microbiologists in this unusual organism. Earlier isolations from humans had also been in immunosuppressed patients following hemolymphatic tumors or renal transplantation. This organism has been recognized for many years as a cause of a serious pyogranulomatous pneumonia of young foals and is occasionally isolated from granulomatous lesions in several other species, in some cases following immunosuppression. The last decade has seen many advances in understanding of the epidemiology, pathogenesis, diagnosis, treatment, and immunity to infection in foals. The particular susceptibility of the foal is not understood but can be explained in part by a combination of heavy challenge through the respiratory route coinciding with declining maternally derived antibody in the absence of fully competent foal cellular immune mechanisms. R. equi is largely a soil organism but is widespread in the feces of herbivores. Its growth in soil is considerably improved by simple nutrients it obtains from herbivore manure. About one-third of human patients who have developed R. equi infections had contact in some way with herbivores or their manure. Others may have acquired infection from contact with soil or wild bird manure. R. equi is an intracellular parasite, which explains the typical pyogranulomatous nature of R. equi infections, the predisposition to infection in human patients with defective cell-mediated immune mechanisms, and the efficacy of antimicrobial drugs that penetrate phagocytic cells.

show abstract

Virulence of Rhodococcus equi for mice.

Cited by 25 publications

References 0 publications

Correlation of In Vitro Properties of Rhodococcus (Corynebacterium) equi with Virulence for Mice

Correlation of In Vitro Properties of Rhodococcus (Corynebacterium) equi with Virulence for Mice

The medically important aerobic actinomycetes: epidemiology and microbiology

Rhodococcus equi: an animal and human pathogen

Contact Info

Product

Resources

About