Disease Information for Rhodococcus Equi Zoonosis/Infection

Clinical Manifestations
Clinical Presentation & Variations
Presentation/Fever in Cellular Immune Defect
AIDS with Chest Infection
AIDS with Pulmonary infiltrate
Disease Progression
Course/Difficult Diagnosis
Demographics & Risk Factors
Exposure Factors
Travel, Geographic & Climate Related Factors
Residence/travel/Farm (work)
Established Disease Population
Patient/AIDS established population
Patient/Cellular immune defect
Patient/Immune compromised/Immune suppressed
Occupational Factors
Occupation/Animal handler/cattle/farms
Laboratory Tests
Microbiology & Serology Findings
Microlab/Acid fast bacteria/specimen
Microlab/Corynebacterium species isolation
Microlab/Gram positive bacteria
Microlab/Pleomorphic bacteria on stain
Abnormal Lab Findings (Non Measured)
CD4 T-Cell Count below 200
CD4 T-Cell Count below 50
Diagnostic Test Results
Xray/Cavitation/Cavitary lung lesion/Chest
Xray/Multiple cavitary lesions of lungs/Chest
Xray/Pulmonary Infiltrates in AIDS/Chest
Xray/Pulmonary Lesion/Nodule/Lung
Xray/Pulmonary Lesions/Lung
Associated Diseases & Rule outs
Rule Outs
Actinomycosis, thoracic
Mycobacterium avium intracellulare
Nocardia, pulmonary
Pneumonia, abscessing staphylococcal
Tuberculosis, pulmonary
Associated Disease & Complications
Necrotizing infections
Necrotizing pneumonia/Lung infection
Opportunistic infections triggers/causes
Pneumonia, unresolved/Chronic
Rhodococcus Equi Zoonosis
Disease Synergy - Causes
Synergy/Immune deficiency
Disease Mechanism & Classification
Specific Agent
AGENT/Actinobacterium (ex)
AGENT/Aerobic bacteria (example)
AGENT/Bacteria (category)
AGENT/Catalase producing bacteria (ex)
AGENT/Coryneform bacteria
AGENT/Endemic disease (ex)
AGENT/Epizootic disease (ex)
AGENT/Gram positive bacteria (ex)
AGENT/Gram positive cocci (ex)
AGENT/Infection/Purulent/pyogenic/suppurative (ex)
AGENT/Intracellular organism pathophysiology
AGENT/Mycolic Acid in Cell wall
AGENT/Nocardia Species/Actinobacter
AGENT/Possible unclassified infectious/specific agent
AGENT/Propionobacterium/corynobacterim bacteria (ex)
AGENT/Rod to Coccus pleomorphism
AGENT/Saprophytic organism (ex)
AGENT/Ubiqitous in soil
PROCESS/INCIDENCE/Regional specific
PROCESS/Infection/agent specific (category)

CDC and Emedicine websites adapted 2006; Treatment erythromycin with rifampin, glycopeptide antibiotics including vancomycin, teicoplanin, and rifampin or macrolide erythromycin, clarithyromic, often combination is used and required ; Rhodococcus equi primarily causes zoonotic infections that affect grazing animals, mainly horses and foals; Although R equi is an unusual cause of infection in humans who are immunocompetent, it nevertheless is emerging as an important pathogen in patients who are immunocompromised; R equi is a facultative, intracellular, nonmotile, non–spore-forming, gram-positive coccobacillus (an organism that has the ability to exist as a coccus or bacillus or intermediate form); Called Rhodococcus because of its ability to form a red (salmon-colored) pigment, R equi can be weakly acid-fast and bears a similarity to diphtheroids; R equi previously was called Corynebacterium equi and currently is grouped with the aerobic actinomycetes; Of the 40 genera in the actinomycetes group, Rhodococcus is placed among the nocardioform bacteria, along with Mycobacterium, Nocardia, Gordonia, Tsukamurella, and Corynebacterium;

It has become an important opportunistic pathogen in patients who are immunocompromised, especially those with acquired immunodeficiency syndrome (AIDS); Infection with R equi is associated with significant mortality; Treatment may require combination antibiotic therapy of prolonged duration, sometimes in combination with surgical therapy; Pathophysiology: Necrotizing pneumonia is the commonest form of infection caused by R equi; Extrapulmonary infections described in human beings include wound infection, subcutaneous abscess, brain abscess, thyroid abscess, retroperitoneal abscess, peritonitis, meningitis, pericarditis, osteomyelitis, endophthalmitis, lymphadenitis, lymphangitis, septic arthritis, osteitis, bloody diarrhea, and fever of unknown origin, among others; Bacteremia and dissemination of infection follow from the primary site of infection, which usually is the lung; The primary source of infection also may be from the alimentary tract;


External Links Related to Rhodococcus Equi Zoonosis/Infection
PubMed (National Library of Medicine)
NGC (National Guideline Clearinghouse)
Medscape (eMedicine)
Harrison's Online (accessmedicine)
NEJM (The New England Journal of Medicine)