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J Clin Microbiol. 2010 April; 48(4): 1508–1509.
Published online 2010 February 24. doi:  10.1128/JCM.02139-09
PMCID: PMC2849542

Soft Tissue Infections Caused by Actinomyces neuii, a Rare Pathogen[down-pointing small open triangle]

José Luis Gómez-Garcés,* Almudena Burillo, and Yolanda Gil
Clinical Microbiology Department
Hospital Universitario de Móstoles
Río Júcar s/n
28935 Móstoles, Spain

Actinomyces neuii rarely causes disease in humans. First described in 1985 in two patients with postcataract endophthalmitis (4), A. neuii represents 17% of all clinical Actinomyces isolates (8), with some 132 cases of infection caused by this microorganism reported to date. The sensitivity of direct Gram staining of skin and soft tissue samples is low (17 to 21%). It grows as round, smooth, convex, opaque, white colonies with complete 0.5- to 1.5-mm-diameter margins on sheep blood agar (SBA) after 48 h of incubation under a 5% CO2 atmosphere or anaerobic conditions. Like most species of the genus, A. neuii is aerotolerant and facultatively anaerobic. Although the different species were traditionally described as branching rods, A. neuii is nonbranching and may appear as short rods or even coccoids (6, 7). A. neuii does not cause typical actinomycosis. Its two subspecies, A. neuii subsp. neuii and A. neuii subsp. anitratus, can be readily identified by the API Coryne test, version 3.0 (bioMérieux). Though most microbiology laboratories use phenotypical methods of identification, the different kits or tests differ in their substrate specificities, so that reactions can vary depending on the system used (2, 17). Identification based on 16S rRNA gene sequence analysis is far more precise (2, 19). The two cases below illustrate its potential pathogenicity.

In case 1, a 28-year-old otherwise healthy man presented with a 3-day fever and an intergluteal indurated cyst. Physical examination revealed a painful, fluctuating, and tender mass diagnosed as a pilonidal sinus. A purulent fluid obtained on aspiration showed many leukocytes and Gram-positive coryneform rods after direct Gram staining.

In case 2, a 48-year-old woman with an uneventful medical history developed a painful lump in the left breast and fever 4 days before admission. On clinical examination, an excruciatingly painful, fluctuating, breast mass with skin erythema was detected. In a sample obtained during surgical debridement, numerous leukocytes but no microorganisms were revealed by Gram staining.

In both cases, Ziehl-Neelsen and modified Ziehl-Neelsen stains were negative. After 48 h of incubation in a 5% CO2 atmosphere and under anaerobic conditions, pure growth was achieved in both cultures on standard microbiological media. In both instances, the microorganism was identified by its staining characteristics, colony morphology, and biochemical reactions as Actinomyces neuii subsp. neuii. Both strains were catalase positive, did not hydrolyze urea or esculin, and fermented many carbohydrates. They showed a characteristic strong CAMP reaction. Phenotypic identification using API Coryne, version 3.0, gave the numerical profile 3410735 in both cases. Species identification of the two strains was confirmed using a BIOLOG GN panel with 95 carbon sources (BIOLOG, Hayward, CA) with a similarity of 96% (T, 0.515) and 100% (T, 0.600), respectively, with Actinomyces neuii subsp. neuii, and by 16S rRNA sequencing (1,157- and 1,390-bp fragments each) using a previously reported method (5). The 16S sequences showed a homology of 99.1% and 99.7% with Actinomyces neuii subsp. neuii (GenBank accession no. AM084228). Both cases were resolved by a course of penicillin V.

In around 50% of cases, the bacterium is detected in patients with abscesses (6, 8, 11). It also appears in patients with diabetic foot osteomyelitis (14), genitourinary infections (8, 13), bloodstream infections and native valve endocarditis (3, 8), pericarditis (12), and biomaterial infections (1, 9, 15, 16, 18). Treatment consists of surgical debridement. Antibiotics are reserved for patients with fever, cellulitis, or immunosuppression. The microorganism is susceptible to most antibiotics but shows diminished susceptibility to aminoglycosides and fluoroquinolones (10). Its frequent interpretation as a skin contaminant hinders its identification.

Footnotes

[down-pointing small open triangle]Published ahead of print on 24 February 2010.

REFERENCES

1. Brunner, S., S. Graf, P. Riegel, and M. Altwegg. 2000. Catalase-negative Actinomyces neuii subsp. neuii isolated from an infected mammary prosthesis. Int. J. Med. Microbiol. 290:285-287. [PubMed]
2. Clarridge, J. E., III, and Q. Zhang. 2002. Genotypic diversity of clinical Actinomyces species: phenotype, source, and disease correlation among genospecies. J. Clin. Microbiol. 40:3442-3448. [PMC free article] [PubMed]
3. Cohen, E., J. Bishara, B. Medalion, A. Sagie, and M. Garty. 2007. Infective endocarditis due to Actinomyces neuii. Scand. J. Infect. Dis. 39:180-183. [PubMed]
4. Coudron, P. E., R. C. Harris, M. G. Vaughan, and H. P. Dalton. 1985. Two similar but atypical strains of coryneform group A-4 isolated from patients with endophthalmitis. J. Clin. Microbiol. 22:475-477. [PMC free article] [PubMed]
5. Drancourt, M., C. Bollet, A. Carlioz, R. Martelin, J. P. Gayral, and D. Raoult. 2000. 16S ribosomal DNA sequence analysis of a large collection of environmental and clinical unidentifiable bacterial isolates. J. Clin. Microbiol. 38:3623-3630. [PMC free article] [PubMed]
6. Funke, G., G. M. Lucchini, G. E. Pfyffer, M. Marchiani, and A. von Graevenitz. 1993. Characteristics of CDC group 1 and group 1-like coryneform bacteria isolated from clinical specimens. J. Clin. Microbiol. 31:2907-2912. [PMC free article] [PubMed]
7. Funke, G., S. Stubbs, A. von Graevenitz, and M. D. Collins. 1994. Assignment of human-derived CDC group 1 coryneform bacteria and CDC group 1-like coryneform bacteria to the genus Actinomyces as Actinomyces neuii subsp. neuii sp. nov., subsp. nov., and Actinomyces neuii subsp. anitratus subsp. nov. Int. J. Syst. Bacteriol. 44:167-171. [PubMed]
8. Funke, G., and A. von Graevenitz. 1995. Infections due to Actinomyces neuii (former “CDC coryneform group 1” bacteria). Infection 23:73-75. [PubMed]
9. Garelick, J. M., A. J. Khodabakhsh, and R. G. Josephberg. 2002. Acute postoperative endophthalmitis caused by Actinomyces neuii. Am. J. Ophthalmol. 133:145-147. [PubMed]
10. Könönen, E., and W. G. Wade. 2007. Propionibacterium, Lactobacillus, Actinomyces, and other non-spore-forming anaerobic Gram-positive rods, p. 872-888. In P. R. Murray, E. J. Baron, J. H. Jorgensen, M. L. Landry, and M. A. Pfaller (ed.), Manual of clinical microbiology, 9th ed., vol. 1. ASM Press, Washington, DC.
11. Lacoste, C., J. Klijanienko, M. C. Escande, P. Jammet, and C. Nos. 2009. Breast Actinomyces neuii abscess simulating primary malignancy: a case diagnosed by fine-needle aspiration. Diagn. Cytopathol. 37:311-312. [PubMed]
12. Levy, P. Y., P. E. Fournier, R. Charrel, D. Metras, G. Habib, and D. Raoult. 2006. Molecular analysis of pericardial fluid: a 7-year experience. Eur. Heart J. 27:1942-1946. [PubMed]
13. Mann, C., S. Dertinger, G. Hartmann, R. Schurz, and B. Simma. 2002. Actinomyces neuii and neonatal sepsis. Infection 30:178-180. [PubMed]
14. Papaefstathiou, K. 2004. Actinomyces neuii isolation from a foot necrotic ulcer in an immunocompromised patient, abstr. 902, p. 1442. 14th Eur. Congr. Clin. Microbiol. Infect. Dis. European Society of Clinical Microbiology and Infectious Diseases, Prague, Czech Republic.
15. Perez-Santonja, J. J., E. Campos-Mollo, E. Fuentes-Campos, J. Samper-Gimenez, and J. L. Alio. 2007. Actinomyces neuii subspecies anitratus chronic endophthalmitis after cataract surgery. Eur. J. Ophthalmol. 17:445-447. [PubMed]
16. Raman, V. S., N. Evans, B. Shreshta, and R. Cunningham. 2004. Chronic postoperative endophthalmitis caused by Actinomyces neuii. J. Cataract Refract. Surg. 30:2641-2643. [PubMed]
17. Sarkonen, N., E. Kononen, P. Summanen, M. Kononen, and H. Jousimies-Somer. 2001. Phenotypic identification of Actinomyces and related species isolated from human sources. J. Clin. Microbiol. 39:3955-3961. [PMC free article] [PubMed]
18. Watkins, R. R., K. Anthony, S. Schroder, and G. S. Hall. 2008. Ventriculoperitoneal shunt infection caused by Actinomyces neuii subsp. neuii. J. Clin. Microbiol. 46:1888-1889. [PMC free article] [PubMed]
19. Woo, P. C., S. K. Lau, J. L. Teng, H. Tse, and K. Y. Yuen. 2008. Then and now: use of 16S rDNA gene sequencing for bacterial identification and discovery of novel bacteria in clinical microbiology laboratories. Clin. Microbiol. Infect. 14:908-934. [PubMed]

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