Rhodococcus equi infections
- Host Animals
- Hosts/Species Affected
- Systems Affected
- Distribution Table
- List of Symptoms/Signs
- Disease Course
- Impact: Economic
- Zoonoses and Food Safety
- Disease Treatment
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Rhodococcus equi infections
International Common Names
- English: lymphadenitis; lymphadenitis in cattle; lymphadenitis in pigs; mastitis; ovine pneumonia
Pathogen/sTop of page Rhodococcus equi
OverviewTop of page
Rhodococcus equi (previously Corynebacterium equi) is a Gram-positive coccobacillus belonging to the nocardioform actinomycete group (Goodfellow et al., 1982). It is a soil-dwelling bacterium that causes pulmonary and extrapulmonary pyogranulomatous infections in a variety of animal species and humans (reviewed by Vázquez-Boland et al., 2013). R. equi is an important cause of disease in foals, primarily those between 1 and 6 months of age (Ellenberger and Genetzky, 1986).
R. equi was first isolated by Magnusson (1923) from cases of foal pneumonia in Sweden. Since then it has been isolated throughout the world from a variety of lesions in a number of different species including pigs, cattle, buffalo, sheep and goats (Barton and Hughes, 1980), but clinical disease is much rarer in these species. It has been suggested that it is an opportunistic pathogen (Barton and Hughes, 1980). R. equi infection is of significance in pigs and cattle, as it can produce lymph node lesions (lymphadenitis) in these species that are difficult to distinguish from those of tuberculosis at postmortem inspection (McKenzie and Donald, 1979; Dvorská et al., 1999; Ocepek and Zdovoc, 2000; Flynn et al., 2001). Misdiagnosis can have serious consequences for the fate of the carcass and of the disease status of the farm from which the animal originated.
R. equi was first isolated from tuberculosis-like lesions of pigs in the 1930s (McCarter et al., 1935; Holth and Amundsen, 1936). Karlson et al. (1940) and Feldman et al. (1940) subsequently reported the isolation of R. equi from the lymph nodes of healthy pigs. The bacterium has since been isolated from the mandibular and submaxillary lymph nodes of pigs with and without tuberculosis-like lesions (Barton and Hughes, 1980; Rao et al., 1982; Takai and Tsubaki, 1985; Takai et al., 1986b; Katsumi et al., 1991; Madarame et al. 1998), but the causative role of R. equi in granulomatous lymphadenitis remains unclear (Takai et al., 1996). In some cases, Mycobacterium spp. and R. equi have been recovered together (Dvorská et al., 1999; Ocepek and Zdovc, 2000). R. equi has occasionally been associated with serious clinical disease in pigs, including one outbreak of oral abscesses and one of pneumonia (Thal and Rutquist, 1959; Rao et al., 1982). R. equi has also been isolated from wild boars (Makrai et al., 2008; Ribeiro et al., 2011; Sakai et al., 2012).
As in pigs, reports of R. equi infection in cattle have mainly been associated with lymph node lesions (Woolcock and Rudduck, 1973; McKenzie and Donald, 1979; Dürrling, 1991; Soedarmanto et al., 1997). In a recent study, the prevalence among 3.3 million cattle examined postmortem was 0.008% (Flynn et al., 2001). There have also been occasional reports of pyometra (Craig and Davis, 1940) and mastitis (Natarajan and Nilakantan, 1974; Garg and Kapoor, 1986; Wani et al., 2003) in cattle associated with R. equi and the bacterium has been isolated from buffaloes in India with mastitis (Rahman and Baxi 1983a,b), vaginal discharge (Rajagopalan and Gopalakrishnan, 1938) and pneumonia (Singh, 1982).
R. equi was isolated from abscesses of goats in the 1970s (Natarajan and Nilakantan, 1974; Whitford and Jones, 1974), but until recently was considered to be a rare cause of disease in this species. R. equi has now emerged as a relatively common cause of disseminated abscesses and mortality in goats (Guerrault et al., 1984; Diteko et al., 1988; Moraal et al., 1990; Ojo et al., 1993; Fitzgerald et al., 1994; Tkachuk-Saad et al., 1998; Davis et al., 1999; Jeckel et al., 2011). Lesions have been observed in the lungs, liver, spleen and lymph nodes. Osteomyelitis due to R. equi infection has also been reported (Carrigan et al., 1988; Kabongo et al., 2005).
Host AnimalsTop of page
|Animal name||Context||Life stage||System|
|Bos grunniens (yaks)||Domesticated host|
|Bos indicus (zebu)||Domesticated host||Cattle & Buffaloes: All Stages|
|Bos taurus (cattle)||Domesticated host|
|Bubalus bubalis (Asian water buffalo)||Domesticated host||Cattle & Buffaloes: All Stages|
|Capra hircus (goats)||Domesticated host||Sheep & Goats: All Stages|
|Equus caballus (horses)||Domesticated host||Other: Juvenile|
|Lama glama (llamas)||Domesticated host, Wild host|
|Ovis aries (sheep)||Domesticated host||Sheep & Goats: All Stages|
|Sus scrofa (pigs)||Domesticated host||Pigs: All Stages|
|wild boar||Wild host|
Hosts/Species AffectedTop of page
R. equi infections are common in foals, but adult horses develop resistance, and rarely show clinical signs of infection (Barton and Hughes, 1980). Infections have been reported sporadically in other species including pigs, cattle, sheep, goats, cats, humans, crocodilians, koalas, buffalo (Barton and Hughes, 1980), dogs (Cantor et al., 1998) and llamas (Hong and Donahue, 1995). Young animals and those with an immunological deficiency seem to be particularly vulnerable to infection (Barton and Hughes, 1980).
Species-specific tropism of R. equi for horses, pigs and cattle appears to be determined by host-adapted virulence plasmid types (Vázquez-Boland et al., 2013).
Systems AffectedTop of page blood and circulatory system diseases of large ruminants
blood and circulatory system diseases of pigs
blood and circulatory system diseases of small ruminants
digestive diseases of large ruminants
digestive diseases of pigs
digestive diseases of small ruminants
mammary gland diseases of large ruminants
multisystemic diseases of large ruminants
multisystemic diseases of pigs
multisystemic diseases of small ruminants
respiratory diseases of large ruminants
respiratory diseases of pigs
respiratory diseases of small ruminants
DistributionTop of page
In its principal host, the foal, R. equi causes disease on a worldwide basis. Infections in foals are usually sporadic, but the disease is endemic on some farms (Barton and Hughes, 1980). In other animals, such as pigs, cattle, sheep and goats, clinical disease is rare but widespread.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
PathologyTop of page
The lesions of R. equi infection are abscesses and granulomas. In cattle, R. equi sometimes occurs in localized lesions that cannot be easily differentiated from tuberculous processes either macroscopically or histologically (McKenzie and Donald, 1979; Rogers et al., 1980). Granulomata resembling tuberculosis have been seen in mesenteric lymph nodes; typically these lesions take the form of coagulation necrosis surrounded by a mixed cellular reaction of plasma cells, fibroblasts, macrophages, epithelioid cells, neutrophils and eosinophils with the occasional Langhans-type giant cell (Woolcock and Rudduck, 1973; McKenzie and Donald, 1979). There is usually mineralization. Flynn et al. (2001) detected lymph node lesions in 6719 cattle, from a total of 3.3 million examined postmortem in abattoirs in the Irish Republic. A total of 1122 of the lesions were cultured for R. equi because the histological findings were difficult to interpret or were suggestive of R. equi infection. R. equi was isolated from 264 lesions, giving a prevalence of 0.008% in the 3.3 million cattle examined. Almost all of the R. equi granulomas were confined to a single lymph node, and were present predominantly in the retropharyngeal, bronchial and mediastinal lymph nodes.
Similarly in pigs, it is not possible to differentiate the gross lesions of R. equi-induced lymphadenitis from those caused by Mycobacterium spp. (Dvorská et al. 1999; Ocepek and Zdovc, 2000). Affected submandibular and cervical nodes are enlarged, containing multiple yellow-tan foci, often in a subcapsular location. Caseation and calcification of these foci sometimes occur (Taylor, 1999).
In goats, postmortem examinations have revealed granulomatous or caseous abscesses in the liver, lungs, lymph nodes and spleen (Whitford and Jones, 1974; Carrigan et al., 1988; Tkachuk-Saad et al., 1998; Davis et al., 1999;). Pulmonary oedema, purulent pneumonia and fibrionopurulent pleuritis have also been recorded (Whitford and Jones, 1974). Carrigan et al. (1988) found osteomyelitis during postmortem examination of an R. equi-infected goat.
In sheep, infection with R. equi has been associated with purulent pneumonia and pleurisy with abscesses in the bronchial lymph glands (Roberts, 1957).
DiagnosisTop of page
Clinical signs of R. equi infection are rare in animals other than horses and diagnosis is usually at postmortem. Gross lesions of R. equi-induced lymphadenitis and those caused by Mycobacterium spp. are very similar (McKenzie and Donald, 1979; Dürrling, 1991; Dvorská et al., 1999). Definitive diagnosis cannot be made on histopathological examination alone, but heavy neutrophil infiltration of necrotic areas is sometimes a distinguishing feature (McKenzie and Donald, 1979). Clumps of intracellular cocci may be detected in the histology slice, but ultimately the diagnosis must be made on bacteriological culture of the fresh material. In sheep and goats, abscesses may be indistinguishable from lesions due to Corynebacterium pseudotuberculosis (Addo and Dennis, 1977).
Isolation of R. equi from clinical samples is easily achieved by aerobic culture on routine media at 37°C, although optimum temperature is 28-30°C. R. equi is identifiable after 2 days of culture. Selective media, such as that developed by Woolcock et al. (1979) are required for faecal isolation.
In foals, a combination of tracheal aspiration and bacterial isolation is the most valuable method for routine diagnosis of R. equi pneumonia. Radiography, serodiagnosis and faecal culture were shown to be valuable, but limited, diagnostic methods (Anzai et al., 1997). PCR tests are being developed for rapid diagnosis of R. equi infection and for use in epidemiological studies (Sellon et al. 1997; Sellon et al. 2001).
The majority of R. equi infections occur in young animals with immature immune responses. In horses, animals older than 6 months show signs of immunizing exposures to R. equi and are relatively resistant (Barton and Hughes, 1980). Humoral and cellular components of the immune system are involved in the clearance of R. equi (Hines et al., 1997). Both appear to be involved in enabling macrophages to kill infecting organisms. The rarity of reports in species other than horses suggests that most animals are resistant to infection unless predisposed by some immunosuppressive factor such as stress, illness or iatrogenic drug immunosuppression, as has been noted in humans receiving immunosuppressive therapy (Berg et al., 1977).
List of Symptoms/SignsTop of page
|Digestive Signs / Diarrhoea||Sheep & Goats:All Stages||Sign|
|General Signs / Fever, pyrexia, hyperthermia||Pigs:All Stages||Sign|
|General Signs / Head, face, ears, jaw, nose, nasal, swelling, mass||Pigs:Piglet||Sign|
|General Signs / Lymphadenopathy, swelling, mass or enlarged lymph nodes||Cattle & Buffaloes:All Stages,Pigs:All Stages,Sheep & Goats:All Stages||Sign|
|General Signs / Neck swelling, mass cervical region||Pigs:Piglet||Sign|
|General Signs / Sudden death, found dead||Sheep & Goats:All Stages||Sign|
|General Signs / Weight loss||Pigs:All Stages,Sheep & Goats:All Stages||Sign|
|Reproductive Signs / Mastitis, abnormal milk||Cattle & Buffaloes:Cow||Sign|
|Respiratory Signs / Purulent nasal discharge||Sheep & Goats:All Stages||Sign|
Disease CourseTop of page
R. equi enters the host by ingestion or inhalation and is spread via the bloodstream. In foals, infection leads to severe, suppurative bronchopneumonia with suppurative lymphadenitis of regional nodes and, in approximately 50% of animals, to necrotizing enterocolitis (Yager, 1987). Infections can be subacute, with foals dying within days of showing respiratory distress, or chronic, with pneumonia and unthriftiness progressing for weeks (Ellenberger and Genetzky, 1986).
In cattle and pigs, the primary targets of R. equi are the lymphoid organs, and the organism has been associated with lymphadenitis (Katsumi et al., 1991; Soedarmanto et al., 1997; Flynn et al., 2001). Lymphadenitis causes no significant clinical signs. R. equi can also be isolated from normal lymph nodes (Mutimer and Woolcock, 1980; Takai et al., 1986b; Katsumi et al., 1991; Madarame et al., 1998; Flynn et al., 2001) and its pathogenic role in pigs has been questioned (Madarame et al., 1998). After exposure of piglets to an aerosol of 107R. equi for seven consecutive days, the only clinical evidence of disease was elevated temperature (Zink and Yager, 1987). Intravenous and intramuscular inoculation of pigs produced no clinical signs other than transient fever and weight loss (Madarame et al., 1998). However, an acute outbreak of R. equi infection, resulting in oedematous swelling of the face, snout and neck has been reported in piglets (Rao et al. 1982).
R. equi is emerging as a relatively common cause of disseminated abscesses in goats (Guerrault et al., 1984; Diteko et al., 1988; Moraal et al., 1990; Ojo et al., 1993; Tkachuk-Saad et al., 1998; Davis et al., 1999) and infection may be fatal in some cases (Fitzgerald et al. 1994). Clinical signs reported by Carrigan et al. (1988) include lethargy, abdominal pain, and green watery diarrhoea. R. equi was reported by Roberts (1957) as the cause of purulent pneumonia and pleurisy with abscesses in the bronchial lymph glands of a sheep from Western Australia. The flock had about 0.5% deaths each year from a wasting disease characterized by nasal discharge. R. equi has also been associated with abortion (Dennis and Bamford, 1966) and bronchopneumonia (Addo and Dennis, 1977), but reports are very rare.
R. equi is a facultative intracellular bacterium and its ability to persist in macrophages forms the core of its pathogenesis (Hondalus, 1997). Its ability to replicate within the macrophage correlates with the possession of a large plasmid and expression of plasmid-encoded virulence associated proteins (Vap). Isolates of R. equi from pneumonic foals typically contain large, 85 or 90 kb plasmids encoding virulence-associated protein A (VapA), a highly immunogenic 15-17 kDa surface lipoprotein. Giguere et al. (1999) showed that the 85 kb plasmid of R. equi is essential for intracellular replication within mouse macrophages and for development of disease in the foal. R. equi strains of intermediate virulence for mice possess a 20 kDa protein designated virulence associated protein B (VapB) and a virulence plasmid of 79-100 kb, and can be recovered from the submaxillary lymph nodes of pigs (Takai et al., 1996; Fukunaga et al., 1999) and the environment of pig farms (Fukunaga et al., 1999). Takai et al. (2000) showed that R. equi strains possessing VapB are less virulent in foals than strains possessing VapA. In a study of R. equi isolates from the lymph nodes of cattle, the 15-17 and 20 kDa antigens, associated with virulence and intermediate virulence, respectively, were not detected (Flynn et al., 2001). In addition to the virulence associated proteins, the pathogenesis of R. equi infection is also thought to involve the granulomagenic activity related to lipids and cell wall structures (Takai et al., 1995).
EpidemiologyTop of page
R. equi is a soil organism that is ingested by many herbivores and is widespread in their environment (Barton and Hughes, 1980; Takai and Tsubaki, 1985; Prescott, 1991). It has been isolated from the faeces of cattle, goats, horses, pigs, poultry and sheep (Carman and Hodges, 1987). Environmental distribution of R. equi favours soils enriched with herbivore manure (Barton and Hughes, 1984; Prescott, 1991). Simple organic acids in faeces of herbivores, especially acetate and propionate, appear to be important for supporting its growth (Hughes and Sulaiman, 1987). The organism is robust and can survive in soil for at least a year and withstand drying and direct sunlight (Ellenberger and Genetzky, 1986). It multiplies progressively as temperatures rise (Prescott, 1987).
Compared with horses, little is known of the epidemiology of natural R. equi infections in livestock. R. equi infection is likely to be acquired from the environment (Woolcock et al., 1980). The normal mode of exposure in foals is ingestion (Takai et al., 1986a) and a similar situation probably occurs in other animals. Although R. equi may reach the lungs of foals after intestinal infection, pneumonic disease is usually the result of direct respiratory infection (Prescott et al., 1980). Aerosol infection via dust of paddocks is a major route of foal infections (Benoit et al., 2000). Foals are also an important source of airborne virulent R. equi as they breathe off high concentrations in exhaled air (Muscatello et al., 2007).
Pigs are extremely resistant to experimental infection. Early studies suggested that pigs are resistant to R. equi given by the oral and nasal routes (Cotchin, 1943; Thal and Rutqvist, 1959), although the organism has been recovered from the cervical and submaxillary lymph nodes of inoculated pigs (Karlson et al., 1940). Cotchin (1943) found that pigs are resistant to intravenous inoculation with R. equi, whereas Thal and Rutqvist (1959) produced local abscesses with regional lymphadenitis after subcutaneous injection of the bacterium. Zink and Yager (1987) showed that R. equi is cleared very slowly from the lungs of pigs after aerosol exposure, but clinical signs and pathological lesions of pneumonia were minimal despite exposure to 107 organisms on 7 consecutive days. Pneumonia has, however, been introduced by intratracheal inoculation of fluid inocula (Thal and Rutqvist, 1959).
There are very few reports of experimental infections in other species. Sheep and cattle have been shown to be refractory to experimental infection (Rajagopalan and Gopalikrishnan, 1938). McKenzie et al. (1981) produced granulomas at the sites of inoculation in cattle inoculated intratracheally, subcutaneously and into a prescapular lymph node, but no lung infections were produced. Magnusson (1923) produced a small local abscess in a goat by subcutaneous inoculation.
Impact: EconomicTop of page
The economic losses due to R. equi infections in pigs, cattle, sheep and goats are insignificant due to the rarity of clinical disease. Some losses may accrue from condemnation at slaughter, but there are no studies that indicate the extent of this loss.
Zoonoses and Food SafetyTop of page
The first report of lesions in man associated with R. equi was by Golub et al. (1967), although there are some indications that it had been isolated previously (Barton and Hughes, 1980). Recently, R. equi has emerged as an important pulmonary pathogen among immunosuppressed patients, especially those with human immunodeficiency virus (HIV) infection (Harvey and Sunstrum, 1991; Lasky et al., 1991; Prescott, 1991; Drancourt et al., 1992; Gradon et al., 1992). The route of infection in human cases remains obscure (Takai et al., 1996). Contact with farm animals and manure has been reported in some of the human cases (Drancourt et al., 1992; Harvey and Sunstrum, 1991; Lasky et al., 1991). Others may have acquired infection from contact with soil or wild bird manure (Prescott, 1991). Takai et al. (1996) found two plasmids in pig isolates that were the same size as those in human isolates. They speculate that some human cases may be of porcine origin.
Disease TreatmentTop of page
R. equi infections are rarely diagnosed antemortem. In foals, therapy requires long-term administration of antibiotics. This is usually not feasible for livestock on economic grounds. Rifampin in combination with erythromycin is effective in the treatment of foals. These expensive drugs can be given orally. They penetrate the phagocytic cells where R. equi are found, and are not toxic when used over prolonged periods. Most R. equi isolates are susceptible to rifampin and erythromycin, but some resistance has been reported (Kenney et al., 1994; Takai et al., 1997).
Prevention and ControlTop of page
There are few incentives to institute control measures in species other than horses. Vaccines have been developed for horses (Becu et al., 1997), but their use in other species is not warranted. Even in horses the sporadic nature of the disease in most situations makes the usefulness of vaccines doubtful (Barton and Hughes, 1980). Administration of hyperimmune plasma to foals has been shown to be useful for prevention of R. equi infections on endemic farms (Becu et al., 1997; Higuchi et al., 1999). As the growth of R. equi is promoted in herbivore faeces, sanitary measures aimed at reducing focal areas of faecal contamination in the environment should lessen the risk for R. equi infection (Hughes and Sulaiman, 1987).
ReferencesTop of page
Addo PB; Dennis SM, 1977. Ovine pneumonia caused by Corynebacterium equi. Veterinary Record, 101(4):80.
Anzai T; Wada R; Nakanishi A; Kamada M; Takai S; Shindo Y; Tsubaki S, 1997. Comparison of tracheal aspiration with other tests for diagnosis of Rhodococcus equi pneumonia in foals. Veterinary Microbiology, 56(3/4):335-345; 33 ref.
Barton MD; Hughes KL, 1980. Corynebacterium equi: a review. Veterinary Bulletin, 50(2):65-80.
Bendixen HC; Jepsen A, 1938. Corynebacterium equi (Magnusson, 1923) som aarsag til tuberkulosilignende suppurationsprocesser hos svin, navnlig I halslymfekirtler. Medlemsbl.danske Dyrlaegeforen 21:401-422.
Benoit S; Taouji S; Benachour A; Hartke A, 2000. Resistance of Rhodococcus equi to acid pH. International Journal of Food Microbiology, 55(1-3):295-298.
Berg R; Chmel H; Mayo J; Armstrong D, 1977. Corynebacterium equi infection complicating neoplastic disease. American Journal of Clinical Pathology, 68(1):73-77.
Biberstein EL, 1990. Corynebacteria; Actinomyces pyogenes; Rhodococcus equi. In: Biberstein EL, ZeeYC, eds. Review of Veterinary Microbiology. Boston, USA: Blackwell Scientific Publications.
Cantor GH; Byrne BA; Hines SA; Richards HMIII, 1998. VapA-negative Rhodococcus equi in a dog with necrotizing pyogranulomatous hepatitis, osteomyelitis, and myositis. Journal of Veterinary Diagnostic Investigation, 10(3):297-300; 15 ref.
Carman MG; Hodges RT, 1987. Distribution of Rhodococcus equi in animals, birds and from the environment. New Zealand Veterinary Journal, 35(7):114-115.
Cotchin E, 1943. Corynebacterium equi in the submaxillary lymph nodes of swine. Journal of Comparative Pathology, 53:298-309.
Craig JF; Davis GO, 1940. Corynebacterium equi in bovine pyometra. Veterinary Journal, 96:417-419.
Dennis SM; Bamford VW, 1966. The role of corynebacteria in perinatal lamb mortality. Veterinary Record, 79(4):105-108.
Dvorská L; Parmová I; Lávicková M; Bartl J; Vrbas V; Pavlík I, 1999. Isolation of Rhodococcus equi and atypical mycobacteria from lymph nodes of pigs and cattle in herds with the occurrence of tuberculoid gross changes in the Czech Republic over the period of 1996-1998. Veterinární Medicína, 44(11):321-330; 44 ref.
Ellenberger MA; Genetzky RM, 1986. Rhodococcus equi infections: literature review. Compendium on Continuing Education for the Practicing Veterinarian, 8(8):s414-s423.
Feldman WH; Moses HE; Karlson AG, 1940. Corynebacterium equi as a possible cause of tuberculosis-like lesions of swine. Cornell Vet., 30:465-481.
Fitzgerald SD; Walker RD; Parlor KW, 1994. Fatal Rhodococcus equi infection in an Angora goat. Journal of Veterinary Diagnostic Investigation, 6(1):105-107; 7 ref.
Flynn O; Quigley F; Costello E; O'Grady D; Gogarty A; McGuirk J; Takai S, 2001. Virulence-associated protein characterisation of Rhodococcus equi isolated from bovine lymph nodes. Veterinary Microbiology, 78(3):221-228.
Fukunaga N; Okoda T; Katsumi M; Takai S, 1999. Restriction cleavage patterns of plasmid DNA of intermediately virulent Rhodococcus equi isolates from the mandibular lymph nodes of pigs in Kagoshima, Aomori and Miyagi prefectures and the environment of pig-breeding farms. Journal of the Japan Veterinary Medical Association, 52(12):789-792; 17 ref.
Garg DN; Kapoor PK, 1986. Isolation and characterization of Rhodococcus (Corynebacterium) equi from cows with mastitis. Indian Journal of Comparative Microbiology, Immunology and Infectious Diseases, 7(2/3):91-95; 20 ref.
Giguere S; Hondalus MK; Yager JA; Darrah P; Mosser DM; Prescott JF, 1999. Role of the 85-kilobase plasmid and plasmid-encoded virulence-associated protein A in intracellular survival and virulence of Rhodococcus equi. Infection and Immunity, 67(7):3548-3557.
Golub BG; Falk G; Spink WW, 1967. Lung abscess due to Corynebacterium equi. Report of first human infection. Annals of Internal Medicine, 66(6):1174-1177.
Goodfellow M, 1987. The taxonomic status of Rhodococcus equi.. Veterinary Microbiology, 14(3):205-209; 8 ref.
Goodfellow M; Beckham AR; Barton MD, 1982. Numberical classification of Rhodococcus equi and related actinomycetes. Journal of Applied Bacteriology, 53(2):199-207.
Guerrault P; Gaillard-Perrin G; Polack B, 1984. Corynebacterium equi infection in a goat in the Deux-Sevres region of France. Les maladies de la chèvre, colloque international, Niort (France), 9-11 octobre 1984., 611-614; [Colloques de l'INRA No.28]; 3 ref.
Harvey RL; Sunstrum JC, 1991. Rhodococcus equi infection in patients with and without human immunodeficiency virus infection. Reviews of Infectious Diseases, 13(1):139-145.
Higuchi T; Arakawa T; Hashikura S; Inui T; Senba H; Takai S, 1999. Effect of prophylactic administration of hyperimmune plasma to prevent Rhodococcus equi infection on foals from endemically affected farms. Journal of Veterinary Medicine. Series B, 46(9):641-648; 14 ref.
Hines SA; Kanaly ST; Byrne BA; Palmer GH, 1997. Immunity to Rhodococcus equi. Veterinary Microbiology, 56(3/4):177-185; 49 ref.
Holth H; Amundsen H, 1936. Fortsatte undersøkelser over baciltypene ved tuberkulose hos svinet på Ostlandet. Norsk Veterinaertidsskrift, 48:2-17.
Hondalus MK, 1997. Pathogenesis and virulence of Rhodococcus equi. Veterinary Microbiology, 56(3/4):257-268; 77 ref.
Hughes KL; Sulaiman I, 1987. The ecology of Rhodococcus equi and physiochemical influences on growth. Veterinary Microbiology, 14(3):241-250.
Karlson AG; Moses HR; Feldman WH, 1940. Corynebacterium equi (Magnusson, 1923) in the submaxillary lymph nodes of swine. Journal of Infectious Diseases, 67:243-251.
Karlson AG; Thoen CO, 1971. Mycobacterium avium in tuberculous adenitis of swine. American Journal of Veterinary Research, 32(8):1257-1261.
Katsumi M; Kodama N; Miki Y; Hiramune T; Kikuchi N; Yanagawa R; Nakazawa M, 1991. Typing of Rhodococcus equi isolated from submaxillary lymph nodes of pigs in Japan. Journal of Veterinary Medicine. Series B, 38(4):299-302; 16 ref.
Kenney DG; Robbins SC; Prescott JF; Kaushik A; Baird JD, 1994. Development of reactive arthritis and resistance to erythromycin and rifampin in a foal during treatment for Rhodococcus equi pneumonia. Equine Veterinary Journal, 26(3):246-248; 15 ref.
Lasky JA; Pulkingham N; Powers MA; Durack DT, 1991. Rhodococcus equi causing human pulmonary infection: review of 29 cases. Southern Medical Journal, 84(10):1217-1220.
Lazovskaya AL; Levanova GF; Kashnikov SYu; Vorob'ev ZG, 2010. Detection of virulence plasmids in Rhodococcus equi strains isolated from pigs and cattle. Russian Agricultural Sciences, 36(4):309-311. http://springerlink.com/content/120687/
Lloyd J; Peet RL, 1979. Corynebacterium equi from a lesion resembling tuberculosis in a bovine lymph node. Australian Veterinary Journal, 55(4):198.
Madarame H; Yaegashi R; Fukunaga N; Matsukuma M; Mutoh K; Morisawa N; Sasaki Y; Tsubaki S; Hasegawa Y; Takai S, 1998. Pathogenicity of Rhodococcus equi strains possessing virulence-associated 15- to 17-kDa and 20-kDa antigens: experimental and natural cases in pigs. Journal of Comparative Pathology, 119(4):397-405; 29 ref.
Magnusson H, 1923. Spezifische Infektiose Pneumonie beim Fohlen: Ein neurer Eitererreger beim Pferde. Arch. Wiss. Prakt. Tierheilk., 50:22-38.
Magnusson H, 1940. Pyämie beim Fohlen und tuberkuloseähnliche Herde der Schweine, verursacht durch Corynebacterium equi. Z. Infektkr. Haust, 56:199-206.
Makrai L; Kobayashi A; Matsuoka M; Sasaki Y; Kakuda T; Dénes B; Hajtós I; Révész I; Jánosi K; Fodor L; Varga J; Takai S, 2008. Isolation and characterisation of Rhodococcus equi from submaxillary lymph nodes of wild boars (Sus scrofa). Veterinary Microbiology, 131(3/4):318-323. http://www.sciencedirect.com/science/journal/03781135
Makrai L; Takayama S; Dénes B; Hajtós I; Sasaki Y; Kakuda T; Tsubaki S; Major A; Fodor L; Varga J; Takai S, 2005. Characterization of virulence plasmids and serotyping of Rhodococcus equi isolates from submaxillary lymph nodes of pigs in Hungary. Journal of Clinical Microbiology, 43(3):1246-1250. http://jcm.asm.org/cgi/content/abstract/43/3/1246
McCarter J; Beach BA; Hastings EG, 1935. The relation of the avian tubercle bacillus to tuberculosis in swine and incidentally in cattle. Journal of the American Veterinary Medical Association, 86:168-175.
McKenzie RA; Donald BA, 1979. Lymphadenitis in cattle associated with Corynebacterium equi: a problem in bovine tuberculosis diagnosis. Journal of Comparative Pathology, 89(1):31-38.
McKenzie RA; Donald BA; Dimmock CK, 1981. Experimental Corynebacterium equi infections of cattle. Journal of Comparative Pathology, 91(3):347-353.
Moitra AK, 1972. Incidence of Corynebacterium equi in bovine pneumonic lungs. Indian Veterinary Journal, 49(10):973-974.
Muscatello G; Lowe JM; Flash ML; McBride KL; Browning GF; Gilkerson JR, 2007. Review of the epidemiology and ecology of Rhodococcus equi. Proceedings of the 53rd Annual Convention of the American Association of Equine Practitioners, Orlando, Florida, USA, 1-5 December, 2007 [Proceedings of the 53rd Annual Convention of the American Association of Equine Practitioners, Orlando, Florida, USA, 1-5 December, 2007.]:214-217. http://www.aaep.org
Mutimer MD; Woolcock JB, 1980. Corynebacterium equi in cattle and pigs. Veterinary Quarterly, 2(1):25-27.
Mutimer MD; Woolcock JB, 1981. Some problems associated with the identification of Corynebacterium equi. Veterinary Microbiology, 6(4):331-338.
Mutimer MD; Woolcock JB, 1982. API ZYM for identification of Corynebacterium equi. Zentralblatt fur Bakteriologie Mikrobiologie und Hygiene, 1 Abt. Originale, C, 3(3):410-415.
Natarajan C; Nilakantan PR, 1974. Studies on corynebacteria of animal origin, their isolation and biochemical characteristics. Indian Journal of Animal Sciences, 44(5):329-333.
Neave RMS, 1951. Outbreak of ulcerative lymphangitis in young heifers in Kenya. Veterinary Record, 63:185.
Ocepek M; Zdovc I, 2000. Rhodococcus equi kot vzrok granulomatoznih sprememb v bezgavkah prasicev, sumljivih na okuzbo z mikobakterijami. Veterinarske Novice, 26(Suppl. 1):35-37.
Ojo MO; Njoku CO; Freitas Jde; Nurse L; Romain H, 1993. Isolation of Rhodococcus equi from the liver abscess of a goat in Trinidad. Canadian Veterinary Journal, 34(8):504; 2 ref.
Pociecha JZ; Mahmoud GS, 1982. Studies on some coryneform bacteria isolated from clinical cases in Mosul area. Indian Journal of Veterinary Medicine, 2(2):8-14.
Poolkhet C; Chumsing S; Wajjwalku W; Minato C; Otsu Y; Takai S, 2010. Plasmid profiles and prevalence of intermediately virulent Rhodococcus equi from pigs in Nakhonpathom province, Thailand: identification of a new variant of the 70-kb virulence plasmid, type 18. Veterinary Medicine International, 2010:491624. http://www.hindawi.com/journals/vmi/2010/491624/
Prescott JF, 1987. Epidemiology of Rhodococcus equi infection in horses. Veterinary Microbiology, 14(3): 211-214.
Prescott JF; Johnson JA; Markham RJF, 1980. Experimental studies on the pathogenesis of Corynebacterium equi infection in foals. Canadian Journal of Comparative Medicine, 44(3):280-288.
Prescott JF; Lastra M; Barksdale L, 1982. Equi factors in the identification of Corynebacterium equi Magnusson. Journal of Clinical Microbiology, 16(5):988-990.
Prescott JF; Zubaidy AJ, 1979. Corynebacterium equi lymphadenitis in Ontario cattle. Canadian Veterinary Journal, 20(6):175.
Pullin JW, 1946. Tuberculous lesions of swine. 1. Survey of lesions found in Eastern Canada. Canadian Journal of Comparative Medicine, 10:159-163.
Rahman H; Baxi KK, 1983a. Corynebacterium equi in mastitis in a buffalo (Bubalus bubalis). Veterinary Record, 112(9):208-209.
Rahman H; Baxi KK, 1983b. Corynebacterium equi in mastitis in a buffalo. Veterinary Record, 113(7):167-168.
Rajagopalan Vr; Gopalakrishnan VR, 1938. The occurrence of Corynebacterium equi in a she-buffalo. Indian Journal of Veterinary Science, 8:225-234.
Rao MS; Zaki S; Keshavamurthy BS; Singh KC, 1982. An outbreak of an acute Corynebacterium equi infection in piglets. Indian Veterinary Journal, 59(6):487-488.
Ribeiro MG; Takai S; Guazzelli A; Lara GHB; Silva AVda; Fernandes MC; Condas LAZ; Siqueira AK; Salerno T, 2011. Virulence genes and plasmid profiles in Rhodococcus equi isolates from domestic pigs and wild boars (Sus scrofa) in Brazil. Research in Veterinary Science, 91(3):478-481. http://www.sciencedirect.com/science/journal/00345288
Roberts DS, 1957. Corynebacterium equi infection in a sheep. Australian Veterinary Journal, 33:21.
Roberts RJ; Hamilton JM, 1968. Tuberculous lymphadenitis in pigs. Veterinary Record, 83(9):215-217.
Rodriguez JL; Acosta B; Navarro R; Gutierrez C, 2000. Rhodococcus equi infection in goat: apropos of two cases. Journal of Applied Animal Research, 18(2):149-151.
Rogers RJ; Donald BA; Schultz K, 1980. The distribution of Mycobacterium bovis in Queensland cattle herds with observations on the laboratory diagnosis of tuberculosis. Australian Veterinary Journal, 56(11):542-546.
Sakai M; Ohno R; Higuchi C; Sudo M; Suzuki K; Sato H; Maeda K; Sasaki Y; Kakuda T; Takai S, 2012. Isolation of Rhodococcus equi from wild boars (Sus scrofa) in Japan. Journal of Wildlife Diseases, 48(3):815-817. http://www.jwildlifedis.org/content/48/3/815.full
Sellon DC; Besser TE; Vivrette SL; McConnico RS, 2001. Comparison of nucleic acid amplification, serology, and microbiologic culture for diagnosis of Rhodococcus equi pneumonia in foals. Journal of Clinical Microbiology, 39(4):1289-1293.
Sellon DC; Walker K; Suyemoto M; Altier C, 1997. Nucleic acid amplification for rapid detection of Rhodococcus equi in equine blood and tracheal wash fluids. American Journal of Veterinary Research, 58(11):1232-1237; 38 ref.
Singh NB, 1982. Corynebacterium equi as causative agent of pneumonia in buffalo calves. Indian Veterinary Journal, 59(8):662.
Soedarmanto I; Oliveira R; Lämmler C; Dürrling H, 1997. Identification and epidemiological relationship of Rhodococcus equi isolated from cases of lymphadenitis in cattle. Zentralblatt für Bakteriologie, 286(4):457-467; 38 ref.
Takai S; Anzai T; Fujita Y; Akita O; Shoda M; Tsubaki S; Wada R, 2000. Pathogenicity of Rhodococcus equi expressing a virulence-associated 20 kDa protein (VapB) in foals. Veterinary Microbiology, 76(1):71-80.
Takai S; Fukunaga N; Ochiai S; Imai Y; Sasaki Y; Tsubaki S; Sekizaki T, 1996. Identification of intermediately virulent Rhodococcus equi isolates from pigs. Journal of Clinical Microbiology, 34(4):1034-1037; 39 ref.
Takai S; Madarame H; Matsumoto C; Inoue M; Sasaki Y; Hasegawa Y; Tsubaki S; Nakane A, 1995. Pathogenesis of Rhodococcus equi infection in mice: roles of virulence plasmids and granulomagenic activity of bacteria. FEMS Immunology and Medical Microbiology, 11(3):181-190; 32 ref.
Takai S; Takeda K; Nakano Y; Karasawa T; Furugoori J; Sasaki Y; Tsubaki S; Higuchi T; Anzai T; Wada R; Kamada M, 1997. Emergence of rifampin-resistant Rhodococcus equi in an infected foal. Journal of Clinical Microbiology, 35(7):1904-1908; 34 ref.
Takai S; Takeuchi T; Tsubaki S, 1986. Isolation of Rhodococcus (Corynebacterium) equi and atypical mycobacteria from the lymph nodes of healthy pigs. Japanese Journal of Veterinary Science, 48(2):445-448; 20 ref.
Taylor DJ, 1999. Pig Diseases, 7th Edition, ISBN 09506932 6X, 18-23.
Thal E; Rutqvist L, 1959. The pathogenicity of Corynebacterium equi for pigs and small laboratory animals. Nord Vet Med, 11:298-304.
Vázquez-Boland JA; Giguère S; Hapeshi A; MacArthur I; Anastasi E; Valero-Rello A, 2013. Rhodococcus equi: the many facets of a pathogenic actinomycete. Veterinary Microbiology, 167(1/2):9-33. http://www.sciencedirect.com/science/journal/03781135
Whitford HW; Jones LP, 1974. Corynebacterium equi infection in the goat. Southwestern Veterinarian, 27(3):261-262.
Woolcock JB; Farmer AMT; Mutimer MD, 1979. Selective medium for Corynebacterium equi isolation. Journal of Clinical Microbiology, 9(5):640-642.
Woolcock JB; Mutimer MD, 1981. Corynebacterium equi in the gastrointestinal tract of ruminants. Veterinary Research Communications, 4(4):291-294.
Woolcock JB; Mutimer MD; Farmer; A-MT, 1980. Epidemiology of Corynebacterium equi in horses. Research in Veterinary Science, 28(1):87-90.
Woolcock JB; Rudduck HB, 1973. Corynebacterium equi in cattle. Australian Veterinary Journal, 49(6):319.
Yager JA, 1987. The pathogenesis of Rhodococcus equi pneumonia in foals. Veterinary Microbiology, 14(3):225-232.
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