A Case of Nocardia brasiliensis in a Gardening Wound
Robekah McDougall – Launceston General Hospital
A 65-year-old male presented to the Emergency Department at the Launceston General Hospital on the 29th of November 2018 with suspected cellulitis on his right arm and wrist. He was also systemically unwell with fever, rigors and was hypotensive. He had a history of rheumatoid arthritis and was on medication that is known to be an immunosuppressant. It was noted that he had initially injured his right wrist gardening 4 weeks prior. Routine pathology tests were ordered. His total WCC was 15.0 109/L, neutrophil count 12.4 109/L and CRP 193 mg/L. These results all pointed towards an infection. At this point the patient was sent to theatre to operate on his infected wrist. A right wrist tissue and right wrist swab was collected and sent to the microbiology department for routine microscopy, culture and sensitivity testing. The direct gram stain of the tissue and the swab showed numerous leukocytes however, no organisms were observed. The culture plates had no growth after 24 hours incubation and were re-incubated for a further 24 hours. After 48 hours incubation, a light growth of dry, white colonies was observed on the chocolate and blood agar CO2 plates. A Gram stain of the colonies was performed, and branching Gram positive bacilli were seen. Following suspicion based upon these results, a Ziehl-Neelsen and Modified Ziehl-Neelsen stain was performed. The Ziehl-Neelsen stain was negative and the Modified Ziehl-Neelsen stain demonstrated partially acid-fast bacilli. These results were pointing towards the isolate being a Nocardia species. As our laboratory is unable to formally identify Nocardia or perform susceptibility testing, this isolate was forwarded to a reference laboratory for confirmation of identification and susceptibility testing. The isolate was later confirmed to be Nocardia brasiliensis by polymerase chain reaction (PCR). The patient is expected to make a full recovery.