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NAME: Aerococcus spp.

SYNONYM OR CROSS REFERENCE: Aerococcus christensenii, Aerococcus sanguinicola, Aerococcus urinae, Aerococcus urinaehominis, Aerococcus viridans (Footnote 1) Aerococcus urinaeequi (previously Pediococcus urinaeequi) (Footnote 2), Aerococcus suis (Footnote 3, Footnote 4).

CHARACTERISTICS: Gram-positive coccoid bacterium that divides on two planes at right angles, resulting in tetrad and cluster arrangements on Gram stains; some pairs and singles may also be found (Footnote 1, Footnote 5). Most Aerococci are facultatively anaerobic (A. viridans is classified as a microaerophile), non-motile, non-spore-forming, and catalase negative, although some strains can produce a weakly positive catalase-like reaction. Cytochrome enzymes are absent (Footnote 1, Footnote 5).


PATHOGENICITY/TOXICITY: A. urinae and A. sanguinicola have been implicated as urinary tract pathogens in patients predisposed to infection such as immunocompromised patients, and elderly men with urinary tract pathologies. A. urinae and A. sanguinicola have also been isolated from blood of patients suffering from urogenic septicaemia, balanitis, soft tissue infections, and endocarditis (Footnote 1, Footnote 4, Footnote 6, Footnote 7). A. viridans has been isolated from patients with meningitis, endocarditis, and bacteremia with granulocytopenia, and from human immunodeficiency virus-positive patients (Footnote 7, Footnote 8). A. viridans is the causative agent of gaffkemia, a fatal lobster disease (Footnote 9, Footnote 10).

EPIDEMIOLOGY: Occurs worldwide (Footnote 3, Footnote 6, Footnote 8).

HOST RANGE: Humans (Footnote 1), pigs (A. suis) (Footnote 3, Footnote 4), horses (A. urinaeequi) (Footnote 2, Footnote 3), lobsters (A. viridans) (Footnote 9, Footnote 10), immunodeficient mice (A. viridans) (Footnote 11).


MODE OF TRANSMISSION: Aerococcus spp. are opportunistic pathogens that are mainly pathogenic in vulnerable patients (Footnote 1, Footnote 8).


COMMUNICABILITY: Not known to be transmitted from human-to-human.


RESERVOIR: Unknown, Aerococci spp. have been isolated from air, vegetation, dust, hospital and marine environments, and in the indigenous microbiota of humans and animals (Footnote 1, Footnote 4, Footnote 12). In humans, A. viridians has been isolated from skin, ears, and eyes (Footnote 1, Footnote 13), A. urinae has been isolated from the urinary tract, A. christensenii has been isolated from vaginal specimens, A. urinaehominis has been isolated from urine and A. sanguinicola has been isolated from urine and blood (Footnote 1).




DRUG SUSCEPTIBILITY: A. viridans is sensitive to macrolides, tetracyclines, and chloramphenicol, and strains are variably sensitive to penicillin (Footnote 1, Footnote 7). A. urinae is susceptible to penicillin, amoxicillin, piperacillin, cefepime, rifampin, and nitrofurantoin (Footnote 1). A. sanguinicola is susceptible to beta-lactam antimicrobials (Footnote 7), cefotaxime, cefuroxime, erythromycin, chloramphenicol, quinupristin-dalfopristin, rifampin, linezolid, and tetracycline (Footnote 1). Although A. viridans is often susceptible to macrolides, tetracyclines, and chloramphenicol, resistance to these antibiotics has been reported (Footnote 1). A. viridans shows low level resistance to aminoglycosides (Footnote 1, Footnote 14). Penicillin resistance among some A. viridans strains has also been reported in the literature (Footnote 7, Footnote 8). A. urinae is resistant to sulfonamides, trimethoprim, and netilmicin (Footnote 1, Footnote 15).

SUSCEPTIBILITY TO DISINFECTANTS: Information specific to Aerococcus spp. is not available; however, most gram-positive cocci are susceptible to disinfectants such as 70 % ethanol (Footnote 16), formaldehyde (Footnote 17) or sodium hypochlorite (Footnote 16, Footnote 17).

PHYSICAL INACTIVATION: Information specific to Aerococcus spp. is not available; however, most vegetative bacteria can be killed by exposure to moist heat (121°C for at least 15 min) and dry heat (160°C for 1 to 2 hours) (Footnote 18).

SURVIVAL OUTSIDE HOST: Survives well in the environment: air, soil, water (Footnote 1, Footnote 5).


SURVEILLANCE: Monitor for symptoms. Culture of the bacteria from clinical specimens such as urine and blood followed by gram staining, and biochemical tests (Footnote 1).

FIRST AID/TREATMENT: Administration of appropriate antibiotic therapy (Footnote 1, Footnote 3). Antibiotic therapy will differ based on the clinical syndrome and the Aerococcus species involved.




LABORATORY-ACQUIRED INFECTIONS: No reported cases of laboratory-acquired infections with Aerococcus spp.

SOURCES/SPECIMENS: Aerococcus spp. have been isolated from the air, soil, water, and human infections (Footnote 1, Footnote 5, Footnote 9, Footnote 11). A. viridans has been isolated from blood, urine, synovial fluid, and CSF (Footnote 5). A. urinae and A. sanguinicola have been isolated from urinary tract samples and blood (Footnote 1).

PRIMARY HAZARDS: Hazard of infection is very low; however, avoid accidental parenteral inoculation, ingestion, and inhalation of infectious droplets (Footnote 19).

SPECIAL HAZARDS: No special hazards.


RISK GROUP CLASSIFICATION: Risk group 2. This risk group applies to the genus as a whole, and may not apply to every species within the genus.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures (Footnote 19). These containment requirements apply to the genus as a whole, and may not apply to each species within the genus.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes (Footnote 19).

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities (Footnote 19).


SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (Footnote 19).

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration (Footnote 19).

STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labeled (Footnote 19).


REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: December 2011

PREPARED BY: Pathogen Regulatory Directorate, Public Health Agency of Canada.

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Public Health Agency of Canada, 2011


Footnote 1
Ruoff, K. L. (2007). Aerococcus, Abiotrophia, and Other Aerobic Catalase-Negative, Gram-Positive Cocci. In P. R. Murray, E. J. Baron, M. L. Landry, J. H. Jorgensen & M. A. Pfaller (Eds.), (9th ed., pp. 443-454). Washington, D.C.: ASM Press.

Footnote 2
Felis, G. E., Torriani, S., & Dellaglio, F. (2005). Reclassification of Pediococcus urinaeequi (ex Mees 1934) Garvie 1988 as Aerococcus urinaeequi comb. nov. International Journal of Systematic and Evolutionary Microbiology, 55(3), 1325-1327.

Footnote 3
Ibler, K., Truberg Jensen, K., Østergaard, C., Wolff Sönksen, U., Bruun, B., Schønheyder, H. C., Kemp, M., Dargis, R., Andresen, K., & Jørgen Christensen, J. (2008). Six cases of Aerococcus sanguinicola infection: Clinical relevance and bacterial identification. Scandinavian Journal of Infectious Diseases, 40(9), 761-765.

Footnote 4
Vela, A. I., García, N., Latre, M. V., Casamayor, A., Sánchez-Porro, C., Briones, V., Ventosa, A., Domínguez, L., & Fernández-Garayzábal, J. F. (2007). Aerococcus suis sp. nov., isolated from clinical specimens from swine. International Journal of Systematic and Evolutionary Microbiology, 57(6), 1291-1294.

Footnote 5
Facklam, R., & Elliott, J. A. (1995). Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci. Clinical Microbiology Reviews, 8(4), 479-495.

Footnote 6
Ebnöther, C., Altwegg, M., Gottschalk, J., Seebach, J. D., & Kronenberg, A. (2002). Aerococcus urinae endocarditis: Case report and review of the literature. Infection, 30(5), 310-313.

Footnote 7
Facklam, R., Lovgren, M., Shewmaker, P. L., & Tyrrell, G. (2003). Phenotypic description and antimicrobial susceptibilities of Aerococcus sanguinicola isolates from human clinical samples. Journal of Clinical Microbiology, 41(6), 2587-2592.

Footnote 8
Uh, Y., Son, J. S., Jang, I. H., Yoon, K. J., & Hong, S. K. (2002). Penicillin-resistant Aerococcus viridans bacteremia associated with granulocytopenia. Journal of Korean Medical Science, 17(1), 113-115.

Footnote 9
Battison, A. L., Cawthorn, R. J., & Horney, B. (2004). Response of American lobsters Homarus americanus to infection with a field isolate of Aerococcus viridans var. homari (gaffkemia): Survival and haematology. Diseases of Aquatic Organisms, 61(3), 263-268.

Footnote 10
Stewart, J. E., Cornick, J. W., Zwicker, B. M., & Arie, B. (2004). Studies on the virulence of Aerococcus viridans (var.) homari, the causative agent of gaffkemia, a fatal disease of homarid lobsters. Diseases of Aquatic Organisms, 60(2), 149-155.

Footnote 11
Dagnæs-Hansen, F., Kilian, M., & Fuursted, K. (2004). Septicaemia associated with an Aerococcus viridans infection in immunodeficient mice. Laboratory Animals, 38(3), 321-325.

Footnote 12
Volterra, L., Bonadonna, L., & Aulicino, F. A. (1986). Fecal streptococci recoveries in different marine areas. Water, Air, & Soil Pollution, 29(4), 403-413.

Footnote 13
Murray, P. R. (1998). Human Microbiota. In L. Collier, A. Balows & M. Sussman (Eds.), Topley & Wilson's Microbiology and Microbial Infectionsm: Systematic Bacteriology (9th ed., pp. 295-306). London: Hodder Arnold Publication.

Footnote 14
Buu-Hoi, A., Le Bouguenec, C., & Horaud, T. (1989). Genetic basis of antibiotic resistance in Aerococcus viridans. Antimicrobial Agents and Chemotherapy, 33(4), 529-534.

Footnote 15
Zhang, Q., Kwoh, C., Attorri, S., & Clarridge III, J. E. (2000). Aerococcus urinae in urinary tract infections. Journal of Clinical Microbiology, 38(4), 1703-1705.

Footnote 16
Sopwith, W., Hart, T., & Garner, P. (2002). Preventing infection from reusable medical equipment: A systematic review. BMC Infectious Diseases, 2

Footnote 17
Rusell, A. D. (2001). Principles of Antimicrobial Activity and Resistance. In S. S. Block (Ed.), Disinfection, Sterilization, and Preservation (5th ed., pp. 31-55). Philadelphia, USA: Lippincott Williams & Wilkins.

Footnote 18
Pflug, I. J., Holcomb, R. G., & Gomez, M. M. (2001). Principles of the Thermal Destruction of Microorganisms. In S. S. Block (Ed.), Disinfection, Sterilization, and Preservation (5th ed., pp. 79-129). Philadelphia, USA: Lippincott Williams & Wilkins.

Footnote 19
Public Health Agency of Canada. (2004). In Best M., Graham M. L., Leitner R., Ouellette M. and Ugwu K. (Eds.), The Laboratory Biosafety Guidelines (3rd ed.). Canada: