1. A Lesser Known Rhodococcus Rhodococcus erythropolis
LOGO
A Lesser Known Rhodococcus
Rhodococcus erythropolis
H. SOULSBY1, L. COTTOM2 & A. DESPANDE1
Queen Elizabeth University Hospital, Govan Road, Glasgow, G51 4TF
2. Glasgow Royal Infirmary, Castle Street, Glasgow, G4 0SF
LOGO
CASE HISTORY
RHODOCOCCUS ERYTHROPLIS
This two and a half year old child with a history of renal hypoplasia leading to chronic kidney disease and daily peritoneal dialysis was admitted from clinic with a fluctuant swelling around his central line. This line was present for monthly iron infusions.
He was clinically well on admission with normal inflammatory markers. Treatment with Clindamycin for a possible Hickman line infection was commenced.
The day after admission two sets of blood cultures from the Hickman line flagged positive with branching gram positive cocci. Vancomycin was therefore added.
This organism was identified as Rhodococcus erythepolis on the MALDI-TOF. It was then sent to the Reference Laboratory and identified as Rhodoccocus species by 16S RNA Sequencing.
The line was subsequently removed and the patient was treated with a further two weeks of Vancomycin and Rifampicin. The patient remained well and was discharged at this point.
Two agents were used as a combination of antibiotics is generally used for the treatment of Rhodococcus infections. The use of Penicllin is avoided because resistance has been shown to develop rapidly during therapy1.
This organism has been isolated from peritoneal fluid, disseminated skin infection, sputum and the vitreous of the eye2. This is the third reported case of bacteraemia with this organism
It is worth highlighting it’s potentially pathogenic nature as there is a risk of dismissing gram positive rods as contaminating ‘diptheroids’ and not going on to further identification.
As the pool of immunosuppressed patients increases in the future cases of infections with non-equi Rhodococcus species such as R. erythropolis are expected.
CONCLUSION:
This organism has been isolated from peritoneal fluid, disseminated skin infection, sputum and the vitreous of the eye2. This is the third reported case of bacteraemia with this organism
It is worth highlighting it’s potentially pathogenic nature as there is a risk of dismissing gram positive rods as contaminating ‘diptheroids’ and not going on to further identification.
As the pool of immunosuppressed patients increases in the future cases of infections with non-equi Rhodococcus species such as R. erythropolis are expected.
DISCUSSION
Rhodococcus is a genus of oligately aerobic non-sporulating, non-motile, gram-positive bacteria. It is in the order Actinomycetales and family Nocardiaceae2.
Rhodococcus have been isolated from a variety of sources, including soils, rocks, groundwater, seawater, plants and animals2.
There has been increased interest in infections caused by Rhodococcus species in humans since the first clinical case caused by Rhodococcus equi was reported in
In contrast to R. equi, the pathogenic potential of Rhodococcus erythroplis as an invasive pathogen is not well known because R. erythropolis has rarely been isolated from human samples. There have been less than ten cases of R. erythropolis infection reported in the literature1,2.
Previous case reports have shown this organism to cause peritonitis during continuous ambulatory peritoneal dialysis, chronic endopthalmitis after lens implantation, skin and soft tissue infections and osteomyelitis1,2.
The first case of bacteraemia was reported in a patient who was TPN fed post oesophageal cancer in Symptoms resolved after removal of this line, as in this case.
BIBLIOGRAPHY
Park, Uh, Jang et al (2011) Rhodococcus erythroplis septicaemia in a patient with acute lymhocytic leukaemia Journal of Medical Microbiology
Baba, Nada, Ohkusu et al (2009) First Case of Bloodstream Infection Caused by Rhodococcus erythropolis. Journal of Clinical Microbiology 47(8)
Weinstock D, & Brown A (2002) Rhodococcus equi: an emerging pathogen. Clin Infect Dise 34,
Gray, P. Thornton H (1928) Soil bacteria that decompose certain aromatic compounds. Zentralbl. Bakteriol. Parasitenkd. Infektkrankh. Hyg. Abt. II 73: 74-96