Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rhodococcus equi”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources
PubMedDate not supplied

Relapsing systemic infection due to Rhodococcus equi in a drug abuser seropositive for human immunodeficiency virus.

A case of recurrent multisystemic infection due to Rhodococcus equi in a patient with antibody to the human immunodeficiency virus (HIV) but without AIDS is reported. This case, which occurred in a woman with a history of alcohol and drug abuse, is, to our knowledge, the first such case described. The infection involved the lungs, kidneys, brain, and bloodstream. Despite several courses of therapy with antibiotics to which her isolates of R. equi were susceptible in vitro, the patient experienced multiple relapses before her death. On the basis of this case and a few others reported in HIV-infected patients, we recommend an initial antibiotic course at least 6-8 weeks in duration, and we suggest that combination antibiotic treatment be considered. We also suggest that infection with R. equi be included in the diagnostic criteria for AIDS.

Actinomycetales Infections↗
PubMed1997

Macroamphiphilic cell envelope components of Rhodococcus equi and closely related bacteria.

Recent progress towards an understanding of the architecture of the mycobacterial cell envelope (P.J. Brennan and H. Nikaido, Annual Review of Biochemistry 64 (1995) 29-63) provides a model with features more generally applicable to cell envelope organisation in other mycolic acid-containing bacteria. Using this archetype, a model for the organisation of the rhodococcal cell envelope is presented here, with particular reference to cell envelope composition in Rhodococcus equi. The likelihood that mycolic acids bound to the cell wall arabinogalactan contribute to the formation of a distinct outer lipid layer is emphasised. Furthermore, the model incorporates recent work which has characterised rhodococcal macroamphiphiles (lipoglycans and lipoproteins), including the VapA virulence-associated lipoproteins of R. equi.

Antigens, Bacterial↗
PubMed1995

Rhodococcus equi Virulence-Associated Antigens and Specific Antibody Response in AIDS Patients Infected with R. equi.

OBJECTIVES: To analyze the expression of the 15- to 17-kDa plasmid-encoded antigens from Rhodococcus equi isolates of 7 AIDS patients and determine the immunologic response to these proteins in the patients' sera. METHODS: The expression of the virulence proteins in R. equi isolates and the specific antibody response were investigated by immunoblotting. Plasmid DNA was analyzed by agarose gel electrophoresis. RESULTS: The only patient infected with a strain carrying the virulence 85-kb plasmid and expressing the 15- to 17-kDa antigens developed a fatal pneumonia and did not produce specific antibodies to the virulence proteins. Of the 6 patients infected with R. equi strains lacking both proteins and plasmid, only 1 subject had a pulmonary disease with poor clinical outcome and exhibited a negligible humoral immune response to R. equi antigenic components, whereas the other patients who produced a remarkable antibody response developed either an asymptomatic infection (1 case) or pneumonia (4 cases) which completely cleared up. CONCLUSIONS: Our findings suggest that R. equi disease can be induced without the expression of the 15- to 17-kDa virulence-associated plasmid-encoded antigens in HIV-infected patients with very low CD4+ cell counts. Nevertheless, both the synthesis of the virulence proteins and a defective humoral immune response to R. equi may contribute to the severity of rhodococcal disease.

Journal Article↗
PubMed1987

Rhodococcus equi in fecal and environmental samples from Kansas horse farms.

Horse farms in Kansas were surveyed for the incidence of Rhodococcus equi. Fecal specimens and soil or cobweb samples were collected from each farm and cultured on selective media. One control farm (with no history of R. equi infection), one farm which had an outbreak 3 and 4 years previously and 2 farms which had R. equi-infected foals that season were surveyed. In addition, fecal samples from 21 horses hospitalized in the Kansas State University Veterinary Hospital were cultured. There was no significant difference in the incidence of R. equi in fecal samples from the 2 farms with recent disease problems. The farm with a history of disease had a significantly higher percentage of positive fecal cultures than the 2 farms with a more recent history of disease. Neither ration composition nor sex of the horses appeared to affect the fecal culture results. Fecal samples from 2 birds on 1 farm were positive for R. equi.

Animals↗
PubMedDate not supplied

Pulmonary malacoplakia associated with Rhodococcus equi infection in an AIDS patient. Report of a case with diagnosis by fine needle aspiration.

BACKGROUND: Malacoplakia is an uncommon, peculiar inflammatory disease with few cytologic descriptions. It is seen mostly in the lower urinary tract, with rare occurrences in the lungs. Escherichia coli is the most common underlying etiologic agent, with only a few cases reported with Rhodococcus equi infection. CASE: A 36-year-old female with AIDS presented with dysphagia, dry cough and fever. Physical examination revealed diffuse bronchi and wheezing. Chest roentgenography showed multiple cavitary lesions bilaterally in the lungs. Fine needle aspiration (FNA) of one of these lesions revealed clusters of granular histiocytes with numerous intracytoplasmic and extracytoplasmic Michaelis-Gutman bodies. Also noted were numerous coccobacillary bacteria, which, on culture, were identified as R equi. Ultrastructural findings are also presented. CONCLUSION: The case illustrates the cytologic findings of malacoplakia in a rare pulmonary lesion associated with R equi infection in an AIDS patient. It reiterates the diagnostic role of FNA in dealing with a nonneoplastic entity for timely and definitive treatment and follow-up.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Infections with Rhodococcus equi in children.

Three cases of serious infection in children, including the first two reports of bacteremia, due to Rhodococcus equi are described. Only seven pediatric cases have been reported to date. In the laboratory, R. equi can easily be misidentified as a nonpathogenic Corynebacterium spp. (diphtheroid) or a Mycobacterium spp. Despite an overall mortality rate of 25% in adults, no pediatric deaths have occurred due to R. equi. The organism is generally susceptible to vancomycin, aminoglycosides, chloramphenicol, and erythromycin, but, optimal duration of antibiotic therapy is unknown. Treatment with multiple antibiotics was successful in all three cases reported here. Although only a small number of cases have been reported in children, R. equi appears to be an important pediatric pathogen.

Actinomycetales Infections↗
PubMed1987

Rhodococcus equi pneumonia in 48 foals: response to antimicrobial therapy.

Case records of 48 foals with pneumonia due to Rhodococcus equi were reviewed. Twenty of the 48 foals survived and 28 died or were euthanized. There was no significant difference between the survivors and non-survivors in the age of onset of illness, duration of illness prior to admission, the mean white blood cell (WBC) count, or the mean plasma fibrinogen content. All foals had R. equi isolated from a tracheobronchial aspirate or lung specimens obtained at necropsy. All organisms were susceptible in vitro (Kirby-Bauer) to erythromycin and gentamicin. Susceptibilities to other drugs were: trimethoprim-sulfamethoxazole (88%), tetracycline (87%), chloramphenicol (83%); 97% were resistant to cephalothin and 83% to penicillin. Thirteen of the 20 surviving foals were treated with erythromycin and/or rifampin. A decline in mortality rate was observed with the introduction of the combination of erythromycin and rifampin. None of the 17 foals treated with penicillin and gentamicin survived. Chronic, active, non-septic synovitis was confirmed in 17 foals. These foals had joint distension with mild or no apparent lameness.

Actinomycetales Infections↗
PubMed1998

[Other infections (Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Salmonella spp., Campylobacter spp., Nocardia asteroides, Rhodococcus equi and Bartonella spp.)].

People infected with human immunodeficiency virus (HIV) are at increased risk for bacterial infections due to HIV-associated immunologic defects. Bacterial infections were found to be, both a predictor of progression to AIDS and a substantial cause of mortality in pre-AIDS stages. Most bacterial infections are caused by Streptococcus pneumoniae, Haemophilus influenzae, Salmonella spp. and Pseudomonas aeruginosa. Rhodococcus equi, Nocardia spp., Campylobacter spp. and Bartonella spp. are less common. Data derived from two AIDS Clinical Trials Group studies showed that the most common bacterial infections were sinusitis (8.5 per 100 episodes per person years [py]), bacterial pneumonia (5.0 per 100 py), bronchitis (4.1 per 100 py) and soft tissue infections (3.5 per 100 py). In this review clinical characteristics and treatment recommendations according to data available in the literature for these infections are summarized.

AIDS-Related Opportunistic Infections↗
PubMed2004

Isolation and characterisation of Mycobacterium avium and Rhodococcus equi from granulomatous lesions of swine lymph nodes in Slovenia.

Granulomatous lesions in bovine and especially swine lymph nodes are still frequently observed during routine veterinary meat inspections even though Mycobacterium bovis infections are no longer detected in domestic animals in Slovenia. Different lymph nodes of pigs (n = 260) were investigated using classical bacteriological and molecular methods. Mycobacterium avium alone was isolated in 47.3% of pigs and in mixed infection with Rhodococcus equi in 3.9% of pigs. R. equi alone was isolated in 27.3% and in mixed infection with mycobacteria other than M. avium in 1.5% of pigs. A total of 133 M. avium isolates were typed using the IS1245, IS901 and FR300 PCR. Almost two thirds (60.9%) of isolates belonged to M. avium hominissuis (IS901-, IS1245+ genotype), 33.8% of isolates belonged to M. avium avium (IS901+, IS1245+ genotype) and 5.3% of isolates remained non-typed. Fifty out of 85 R. equi isolates were tested for the virulence-associated antigens (VapA and VapB). Nearly two thirds (60.0%) were positive for VapB while all the other isolates were VapA- and VapB-negative.

Actinomycetales Infections↗
PubMedDate not supplied

Application of Sartwell's model (lognormal distribution of incubation periods) to age at onset and age at death of foals with Rhodococcus equi pneumonia as evidence of perinatal infection.

The distributions of the incubation periods for infectious and neoplastic diseases originating from point-source exposures, and for genetic diseases, follow a lognormal distribution (Sartwell's model). Conversely, incubation periods in propagated outbreaks and diseases with strong environmental components do not follow a lognormal distribution. In this study Sartwell's model was applied to the age at onset and age at death of foals with Rhodococcus equi pneumonia. The age at onset of clinical signs and age at death were compiled for 107 foals that had been diagnosed with R. equi pneumonia at breeding farms in Argentina and Japan. For each outcome (disease and death), these data followed a lognormal distribution. A group of 115 foals with colic from the University of California were used as a comparison group. The age at onset of clinical signs for these foals did not follow a lognormal distribution. These results were consistent with the hypothesis that foals are infected with R. equi during the 1st several days of life, similar to a point-source exposure.

Actinomycetales Infections↗
PubMed1987

Studies of the pathogenesis of Rhodococcus equi infection in foals.

Pyogranulomatous pneumonia was induced in Thoroughbred foals by intranasal challenge with freeze-dried cultures of Rhodococcus equi (previously Corynebacterium equi). The incubation period was about 18 days and clinical signs were not seen for a further week. There were marked seasonal and individual foal differences in responses to infection. Elevations in serum caeruloplasmin oxidase activity and copper concentrations appeared to be sensitive indicators of infection. Serum zinc concentrations and serum alpha-mannosidase and alkaline phosphatase activities fell in the more severely infected foals. Use of trace elements and trace element-related parameters along with faecal culture for R. equi could prove useful for early diagnosis of field cases.

Actinomycetales Infections↗
PubMedDate not supplied

Peripheral blood lymphocyte subpopulations and immunoglobulin concentrations in healthy foals and foals with Rhodococcus equi pneumonia.

Infectious diseases are common in foals aged 1-5 months. The objectives of this investigation were to evaluate immunologic parameters in foals from birth to weaning to establish reference values for the proportion of circulating lymphocytes that were helper (CD4+) or cytotoxic (CD8+) T cells, or B cells; to measure serum immunoglobulin (IgM and IgG) concentrations; and to compare these immunologic parameters to values in foals with naturally occurring Rhodococcus equi pneumonia and in adult horses. Peripheral blood lymphocyte subpopulations were determined by flow cytometric analysis, and serum IgG and IgM concentrations were determined by radial immunodiffusion. Flow cytometric analysis of lymphocyte subpopulations suggested age-related changes in the cell-mediated immune system in horses. Absolute circulating CD4+ and CD8+ T lymphocytes and B cells increased linearly up to 3 months of age. Circulating B cell concentrations from birth to 6 months of age were greater than values in adult horses and the lymphocyte differences among the age groups are mainly due to variation in B lymphocytes. Both absolute and proportional B cell concentrations were greater in foals with R equi pneumonia than in healthy foals at the same age. The increase in absolute cell counts of each subpopulation was dependent on the increase of absolute peripheral blood lymphocyte count. Serum IgG concentration increased linearly from 1 to 3 months of age, and serum IgM concentrations increased from 1 to 6 months of age. These data suggest age-dependent cell-mediated and humoral development in young foals.

Actinomycetales Infections↗
PubMed1996

Cytologic features of pulmonary malakoplakia related to Rhodococcus equi in an immunocompromised host.

Cytologic features are described in bronchial brushings of a large cavitary lung mass from an immunosuppressed patient who had undergone liver transplantation. Scattered histiocytes with abundant eosinophilic, vacuolated cytoplasm were noted in a background of bronchial cells. Within approximately one fourth of the histiocytes, targetoid intracytoplasmic inclusions were present, consistent with Michaelis-Gutmann bodies. They were diffusely positive by histo-chemical staining with von Kossa, Gomori methenamine silver, and periodic acid-Schiff stains, and focally positive with Prussian blue stain. Cultures of the abscess yielded Rhodococcus equi. The characteristic microscopic features of pulmonary malakoplakia can be discerned in bronchial brushings, and should be sought, particularly in immunocompromised patients.

Cytodiagnosis↗
PubMed2003

Osteomyelitis of the pelvis caused by Rhodococcus equi in a two-year-old horse.

A 2-year-old female Quarter Horse was evaluated for hind limb lameness, fever (40 degrees C [104 degrees F]), and lethargy of 2 weeks' duration. Hypoproteinemia characterized by hypoalbuminemia and hyperfibrinogenemia was detected. Abdominal ultrasonography revealed thickening of the right dorsal colon wall. Treatment was instituted for putative right dorsal coliis. Lameness evaluation localized signs of pain to the lumbar vertebrae or pelvis. Radiography performed with the horse standing and nuclear scintigraphy revealed no abnormalities. Ventrodorsal pelvic radiography revealed a focal area of bony lysis and proliferation involving the cranial portion of the pubic symphysis. Aspiration yielded purulent exudate containing Rhodococcus equi, which was susceptible to erythromycin. Treatment included surgical debridement of the abscess and oral administration of erythromycin and rifampin. The horse's hind limb lameness completely resolved within 20 days. Infections of the pubic symphysis should be considered when lameness localized to the pelvis is associated with fever and an inflammatory leukogram.

Actinomycetales Infections↗
PubMed1987

Use of erythromycin-rifampin combination in treatment of Rhodococcus equi pneumonia.

The selection of lipid-soluble antibiotics capable of intracellular penetration is considered critical for the successful treatment of Rhodococcus equi pneumonia and lung abscesses in foals. Two such antibiotics: erythromycin (25 mg kg-1, three times daily) and rifampin (5 mg kg-1 twice daily) have been used in combination for this purpose at the University of Florida since 1981. Positive evidence of R. equi was present on culture of tracheal aspirates in 57 foals, most of which exhibited radiographic evidence of extensive lung abscessation. The duration of therapy ranged from 4 to 9 weeks. Mild diarrhea was sometimes noted, but was never severe enough to require the termination of therapy. No other adverse side effects were apparent. Judged by a return of chest radiographs and hematologic parameters to normal, 50 of the 57 foals were considered to have recovered from the disease; a success rate of 88%.

Actinomycetales Infections↗
PubMed1987

The taxonomic status of Rhodococcus equi.

The species Corynebacterium equi was proposed for strains isolated from foals suffering from purulent pneumonia. The taxon has had a confused history and is currently listed under both Corynebacterium and Rhodococcus in the Approved Lists of Bacterial Names. Data from modern taxonomic studies indicate that Corynebacterium equi Magnusson 1923 should be reduced to a synonym of Rhodococcus equi (Magnusson) Goodfellow and Alderson 1980. Rhodococcus equi has repeatedly been shown to be a good species on the basis of chemical, molecular biological, numerical phenetic and serological data. Improved methods are needed to differentiate Rhodococcus equi from closely related species of Rhodococcus.

Nocardiaceae↗
PubMed2006

Granulomatous lesions in lymph nodes of slaughter pigs bacteriologically negative for Mycobacterium avium subsp. avium and positive for Rhodococcus equi.

The prevalence of granulomatous lesions in lymph nodes of pigs was studied. From January till August 2004 in two slaughterhouses in The Netherlands 2,116,536 pigs were examined for the presence of granulomatous lesions in the sub-maxillary lymph nodes. In 15,900 (0.75%) of these pigs, lesions could be detected. Nine farms with the highest incidence of lesions were selected for a more detailed pathological and bacteriological examination. On these farms, the prevalence of lesions in sub-maxillary lymph nodes ranged from 2.3 to 5.7% with a mean of 3.0%. From 1276 pigs that were sampled, 98 (7.7%) displayed granulomatous lesions in the sub-maxillary lymph nodes and one (0.1%) pig showed lesions in its mesenteric lymph node. Mycobacterium avium subsp. avium (MAA) could not be isolated from the lymph nodes of the 99 pigs with lesions and from a selection of lymph nodes (n=61) of pigs without lesions. Rhodococcus equi was isolated from 44 out of 98 (44.9%) of the sub-maxillary lymph nodes with granulomatous lesions and from two mesenteric lymph nodes without lesions. A comparison of former studies and the current results indicate that the prevalence of MAA infections in slaughter pigs has strongly decreased over the last decade, whereas R. equi is highly prevalent. The high incidence of granulomatous lesions associated with the bacteriological presence of R. equi could be considered as a serious cause of misdiagnosis of MAA infections in cases where meat inspection is carried out by inspection for granulomatous changes of lymph nodes only.

Actinomycetales Infections↗
PubMed1999

Pulmonary malacoplakia associated with Rhodococcus equi infection in a patient with AIDS.

An AIDS patient with a cavitary lung lesion was found to have pulmonary malacoplakia associated with Rhodococcus equi infection. The diagnosis was based on the typical histologic features of transbronchial biopsy and a positive bacterial culture. All 13 reported cases of AIDS patients with pulmonary malacoplakia were associated with R equi. The recognition of this unique entity is important because of its responsiveness to therapy.

Acquired Immunodeficiency Syndrome↗