Infections Caused by Actinomyces neuii: A Case Series and Review of an Unusual Bacterium

Table 1

Characteristics of patients from which A. neuii was detected and susceptibility profiles of isolates.

Age, sex	Comorbidities	Infection	Gram smear	Coisolates	MICs of A. neuii isolates (mg/L)	Treatment
30, M	Previous head injury, right ACL repair	Left thigh abscess	4+WBC; 4+GPC; 4+GPB	Prevotella bivia; Anaerobic GPC	Penicillin G 0.016; Amox/clav 0.016; Imipenem 0.023; Vancomycin 0.5; Clindamycin 256	Incision and drainage; Cephalexin 7 days
45, M	TIIDM, dyslipidemia	Left inguinal abscess	3+WBC; 2+GPC; 2+GNB; 1+GPB	Staphylococcus lugdunensis; Anaerobic GPC	Penicillin G 0.016; Amox/clav 0.016; Imipenem 0.023; Vancomycin 0.5; Clindamycin 0.016	Incision and drainage; Cephalexin 7 days
46, M	Paraplegia, renal calculi, atrial fibrillation, previous endocarditis, sacral ulcer	Right axillary abscess	3+WBC; 3+GPB; 2+GPC	None	Penicillin G 0.03; Amox/clav 0.016; Imipenem 0.023; Vancomycin 0.5; Clindamycin 0.016	Incision and drainage; Cephalexin (unknown duration)
48, M	Hypertension, TIIDM, obesity, previous Fournier’s gangrene, diabetic foot infections	Right groin abscess	3+WBC; 3+GPB; 3+GNB; 2+GPC	Proteus mirabilis; Staphylococcus lugdunensis; Actinomyces sp.; Mixed anaerobes	Penicillin G 0.006; Amox/clav 0.016; Imipenem 0.023; Vancomycin 0.5; Clindamycin 0.023	Incision and drainage; Ceftriaxone 3 days; Ertapenem 5 days; Amox/clav 10 days
68, M	Bilateral spermatoceles with spermatocelectomies	Postoperative right scrotum abscess	2+WBC; 3+GPC; 2+GPB; 2+GNB	Coagulase-negative Staphylococcus; Coryneform bacillus; Propionibacterium sp.	Penicillin G 0.016; Amox/clav 0.016; Imipenem 0.032; Vancomycin 0.5; Clindamycin 0.032	Ciprofloxacin 28 days
85, F	Hypertension, hypothyroidism, celiac disease	Postbiopsy left ankle ulcer	3+GNB; 2+GPC	Acinetobacter baumannii/calcoaceticus complex; Streptococcus agalactiae	Penicillin G 0.06; Amox/clav 0.016; Imipenem 0.023; Vancomycin 0.38; Clindamycin 0.023	Wound care; Clindamycin 10 days; Cephalexin 7 days

TIIDM, type II diabetes mellitus; ACL, anterior cruciate ligament.
WBC, white blood cells; GPC, Gram-positive cocci; GPB, Gram-positive bacilli; GNB, Gram-negative bacilli; for WBC, 1+ represents <1 cell per high power field (100 oil immersion lens), 2+ represents 1–5 cells, 3+ represents 6–10 cells, and 4+ represents >10 cells; for bacteria, 1+ represents 1 cell per high power field, 2+ represents 2–10 cells, 3+ represents 11–50 cells, and 4+ represents >50 cells.
MIC, minimal inhibitory concentration; amox/clav, amoxicillin-clavulanate.