A Rare Case of a Subcutaneous Abscess Caused by Nocardia cyriacigeorgica in an Immunocompetent Patient

Figures & data

Table 1 Clinical and Laboratory Indicators of the Patient

Laboratory Indicators/Clinical Indicators	Measurements/Measurements	Normal Interval
WBC	6.83×10^9 /L	3.5–9.5×10^9 /L
Lymphocytes	17.4%	20–50%
Monocytes	5.3%	3–10%
Neutrophils	75.6%	40–75%
Eosinophils	0.09×10^9 /L	0.02–0.52×10^9 /L
Basophils	0.03×10^9 /L	0–0.06×10^9 /L
RBC	3.98×10^12 /L	3.8–5.1×10^12 /L
Hemoglobin	121 g/L	115–150 g/L
Platelets	196×10^9 /L	125–350×10^9 /L
CRP	29.1 mg/L	<10 mg/L
ESR	2 mm/h	<26 mm/h
Right iliopsoas MS	Level 5
MS of right quadriceps femoris	Level 5
Right foot dorsum extensor MS	Level 1
Right foot planar flexor MS	Level 5
Right great toe Dorsum flexor MS	Level 1
Right plantar flexor MS	Level 5
Tendon reflex	++
Blood pressure	115/79 mmHg
Respiratory rate	18 Breaths/minute
Heart rate	75 Beats/minute
Temperature	36.9°C

Abbreviations: WBC, white blood cell count; RBC, red blood cell count; C-reactive protein, CRP; ESR, erythrocyte sedimentation rate; MS, muscle strength.

Figure 1 Imaging examination. (A) Magnetic resonance imaging (MRI) of vertebra lumbalis showed a 26 mm × 73 mm subcutaneous abscess with low signal intensity on T1WI and high signal intensity on T2WI (arrows). (B) The chest radiograph showed that the patient’s lungs were normal.

Table 2 Antimicrobial Susceptibility of the Nocardia Cyriacigeorgica by Kirby–Bauer method and Epsilometer Test

Antibiotics	Method	Result	Breakpoint	Unit	Interpratation
Amoxicillin/clavulanic acid	Etest	4	8–32	μg/mL	S
Amikacin	KB	23	–	mm	–
Clarithromycin	KB	15	–	mm	–
Minocycline	KB	18	–	mm	–
Imipenem	Etest	0.25	1–4	μg/mL	S
Linezolid	Etest	1	4–8	μg/mL	S
Levofloxacin	Etest	8	–	μg/mL	–

Figure 2 Pathogenic examination. (A) Gram-positive and branching rod-shaped bacterium was observed by Gram staining under oil mirror (×1000 magnification). (B) Acid fast staining showed weak positive mycelia, which proved that it was probably Nocardia spp. (C) Wrinkled, dry and white colonies of different sizes were observed by culture on the blood plate. (D) Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) confirm it was Nocardia cyriacigeorgica.