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

Table 2

Characteristics of previously reported cases of A. neuii infections in the literature.

Infection	Number of cases	Coisolates	Treatment	Outcomes	References
Abscess/infected atheroma	56	Coagulase-negative staphylococci; Enterococcus spp.; Corynebacterium spp.; Anaerobes	Incision and drainage, with or without antibiotic therapy (usually -lactams, occasionally tetracycline, ciprofloxacin)	Generally favourable if source control is achieved	[6, 17, 19, 22–26]
Cutaneous infection	9	Coagulase-negative staphylococci (eight cases)	Not reported	Favourable	[17, 19]
Genitourinary infection	6	None	Antibiotic therapy with β-lactams	Favourable	[19, 27]
Bacteremia	8	None	Two cases reported therapy: Ampicillin with gentamicin (two weeks), followed by PO penicillin (four weeks); Initial ciprofloxacin followed by imipenem	Generally favourable (one mortality)	[19, 27]
Endocarditis	1	None	Aortic valve excision with homograft implantation followed by ampicillin (three weeks), ceftriaxone (nine weeks), and then PO doxycycline (nine months)	Favourable	[28]
Chronic pericarditis	1	None	Pericardial fluid drainage and antibiotic therapy (specific antibiotics not reported)	Not reported	[29]
Lymphadenitis	1	Viridans group streptococci; Prevotella timonensis; Anaerobic Gram-positive cocci	Lymph node and fistula excision followed by IV and then PO amoxicillin-clavulanate (six months)	Favourable	[30]
Osteomyelitis	2	Dermabacter hominis (one case)	Surgical curettage followed by -lactam therapy for multiple months	Favourable	[25, 31]
Peritonitis (secondary to peritoneal dialysis)	2	None	Catheter retention with either intraperitoneal cefazolin and ceftazidime (two weeks) followed by penicillin G (four weeks), or intraperitoneal ampicillin, teicoplanin, and tobramycin (two weeks)	Favourable	[32, 33]
Endophthalmitis	6	None	Various systemic (PO or IV) and direct (intravitreal or subconjunctival injections, drops) antibiotics	Favourable	[34–38]
Prosthetic material infection	8	Typically none; Coagulase-negative staphylococci and mixed anaerobes (breast implant case)	Removal/replacement of prosthetic material followed by prolonged antibiotic therapy (weeks to one year, depending on the infection)	Favourable	[25, 39–45]

Including breast, axillary, inguinal, iliac crest, ischiorectal, and pilonidal abscesses; one case of hidradenitis suppurativa; most sites were not specified.
Including ulcer infections, diabetic foot ulcer infections, and cellulitis.
Including urinary tract infections, prostatitis, and chorioamnionitis.
Including one case of neonatal sepsis secondary to chorioamnionitis; the remaining cases had unclear or unreported sources.
The patient treated with this regimen is the single mortality reported in the literature associated with A. neuii infection.
Including infections of an intravenous catheter, a mechanical heart valve, a hip prosthesis, a penile prosthesis, breast implants, and ventriculoperitoneal shunts.