Thread by @IUIDfellowship

#idboardreview 30 F 🇦🇺 s/p biomesotherapy presents with skin lesions. Biopsy shown citrate+ catalase+ oxidase- nitrate-
Diagnosis? #medEd #idmedEd #IDtwitter

#Mycobacterium chelonae #NTM wwwnc.cdc.gov/eid/article/19…

#mycobacterium #chelonae more dramatic presentation here in a gardener sciencedirect.com/science/articl…

M #chelonae ubiquitous in environment: soil, water, and aquatic animals. grows at 30-32 °C commonly associated w/ skin and soft tissue infections, especially of extremities (cellulitis, abscessus). Can causes catheter-related or post-surgical infections post implants, injections

bacteremia, osteomyelitis, intraabdominal abscess, disseminated cutaneous infections common in immunosuppressed on steroids, monoclonal antibodies, post-transplant immunosuppression. cancer and or CKD also susceptible to disseminated and invasive disease due to M. #chelonae

Skin lesions due to M. #chelonae rusk: sclerotherapy, acupuncture tattoos, other injections. Skin lesions can progress to pustules, hemorrhagic crusts, and abscess formation. M. chelonae can also present with Nodular lymphangitis (sporotrichoid lymphocutaneous infection)

M. #chelonae uniformly resistant to cefoxitin. Isolates are susceptible to tobra, clarithromycin, linezolid. Less susceptible to imipenem (60%), amikacin (50%), clofazimine, doxycycline (25%), and ciprofloxacin (20%).

SSTI: Use 2 agents x 4 months #chelonae tmp-smx, levaquin, doxy, clarithro/azithro

#NTM cmr.asm.org/content/32/1/e…

Biochemically, M #chelonae are nitrate negative, do not tolerate 5% NaCl, fail to turn dark brown when grown on ferric ammonium citrate (iron uptake).

M#chelonae & M#abscessus can be separated biochemically by citrate
#chelonae 100% citrate+ unlike #abscessus 80% citrate-
chelonae catalase+ oxidase-
but biochemical methods inadequate for clinical use. molecular techniques are used for diagnosis of atypical NTM

Previous case #mycobacterium #chelonae

https://twitter.com/IUIDfellowship/status/1318337335021502465