NAME: Moraxella spp.
SYNONYM OR CROSS REFERENCE: M. atlantae, M. bovis, M. canis, M. caprae. M. catarrhalis, M. equi, M. lacunata, M. lincolnii, M. nonliquefaciens, M. oblonga, M. osloensis, M. pluranimalium. Moraxella phenylpyruvica is now known as Pyschrobacter phenylpyruvicus.
CHARACTERISTICS: The genus Moraxella is a member of the family Moraxellaceae; these are coccobacillary gram negative rods that are usually in short chains or pairs(1,2). For the most part, they are non-motile in liquid; however, some species have a "twitching" mobility(2). Species that are rod shaped range from 1.0-1.5 x 1.5-2.5 μm in size and species that are cocci shaped are 0.6-1.0 μm in diameter(2). Most species are aerobic, and oxidase and catalase positive(2).
PATHOGENICITY/ TOXICITY: Moraxella species are normally present in the oropharynx, mucous membranes, skin, and genital tract, although they can cause certain diseases in humans(1-4). Moraxella catarrhalis is the most commonly isolated species and is responsible for cases of acute otitis media (in children older than 3 months old), chronic and serious otitis media (fever, acute ear pain, irritability, and can escalate to sepsis and CNS infection), acute and chronic sinusitis (occasional fever, nasal or postnasal discharge, cough, fetid breath, sinus pain, and headache), upper and lower respiratory tract infections and sometimes systemic infections, meningitis, bacteraemia, endocarditis, keratitis and suppurative arthritis(1-4). Other Moraxella species can cause conjunctivitis and keratitis (Moraxella lacunata), meningitis, and arthritis (Moraxella oloensis), endocarditis (Moraxella lacunata), osteomyelitis (Moraxella oloensis), upper and lower respiratory tract infections (Moraxella nonliquefaciens) and otolaryngologic infections (Moraxella lacunata)(2-4). Several species are found in the natural human flora; however, their pathogenicity, if any, has not been established(2).
EPIDEMIOLOGY: These bacteria are disseminated worldwide. Infections with these bacteria are most commonly seen in cold months(4). Epidemics of conjunctivitis due to this bacterium have been reportedly caused by girls sharing makeup(4). 75% of children and 1-3% of healthy adults are carriers for the bacterium(5).
HOST RANGE: Humans and mammals (cattle, horses, sheep, mice, cats, dogs, goats, guinea pigs, rabbits and pigs)(2).
INFECTIOUS DOSE: Not known
MODE OF TRANSMISSION: Person-to-person spread can occur, especially in hospitals (nosocomial infections)(6). Environmental contamination and aerosol transmission are also possible modes of transmission(5,6).
INCUBATION PERIOD: Not clearly defined
RESERVOIR: Moraxella species have been isolated from the conjunctiva, upper respiratory tract, blood, inflammatory secretions of the middle ear, maxillary sinus, bronchial aspirate, nasal cavity, spleen, cerebrospinal fluid, genitourethral tract, joints and bursa of humans(2). They have also been found in conjunctivae and nasal cavities of cattle, sheep, horses, saliva of dogs and cats, mouth and pharynx of guinea pigs and rabbits, nasal cavity of goats, genital tract of pigs, intestines of goats, and genital tract and brain of sheep and cattle(2). Pathogenicity and infectivity of several species of Moraxella is not known(2).
ZOONOSIS: Several animal species are hosts to various Moraxella species, and although zoonosis has not been documented, it may occur(2).
DRUG SUSCEPTIBILITY: Moraxella species, with the exception of Moraxella catarrhalis, are susceptible to penicillin(1,2). Moraxella catarrhalis is resistant to penicillin, ampicillin, amoxicillin, vancomycin, and clindamycin but susceptible to amoxicillin-clavulanate, expanded-spectrum or broad-spectrum cephalosporins, tetracyclines, rifampin, and erythromycin(3,4,7). Most Moraxella species are also susceptible to cephalosporins, tetracyclines, quinolones, and aminoglycosides(3).
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 2-5% phenol, 1% sodium hypochlorite, 4% formaldehyde, 2% glutaraldehyde, 70% ethanol, 70% propanol, 2% peracetic acid, 3-6% hydrogen peroxide, and iodine(8).
PHYSICAL INACTIVATION: Bacteria are susceptible to moist heat (121 °C for at least 15 minutes) and dry heat (160-170 °C for at least 1 hour)(9).
SURVIVAL OUTSIDE HOST: Moraxella bovis has been found to survive up to 3 days on insect legs and Moraxella nonliquefaciens can survive up to 40 weeks if stored at temperatures between -70 and -80 °C(10,11). The bacteria may also survive up to 27 days in dried secretions in the environment(12). M. catarrhalis can survive in expectorated sputum for at least 3 weeks(13).
SURVEILLANCE: Monitor for symptoms. Culture and biochemical tests are used to identify Moraxella in laboratories(14). Molecular detection methods have also been used for nosocomial infections in hospital settings(15).
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Antibiotic therapy may be used, where necessary(1).
PROPHYLAXIS: Antibiotic prophylaxis for children with recurring otitis media has been shown to be effective(17).
LABORATORY-ACQUIRED INFECTIONS: No infections reported to date.
SOURCES/SPECIMENS: Depending on the species, Moraxella have been isolated from various secretions in humans which could be a potential source of infection(2). Because zoonosis could be possible, infected animals and their secretions could also be infective(2).
PRIMARY HAZARDS: Primary hazards include mucocutaneous contact with the infective agent, accidental parenteral inoculation and aerosol exposure(18).
SPECIAL HAZARDS: None
RISK GROUP CLASSIFICATION: Risk group 2(19).
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures. 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(20). Eye protection must be used where there is a known or potential risk of exposure to splashes.
OTHER PRECAUTIONS: All procedures that may produce aerosols, involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC)(20). 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.
SPILLS: Allow aerosols to settle, then, wearing protective clothing, gently cover the spill with absorbent paper towel and apply the appropriate disinfectant starting at the perimeter and working towards the center. Allow sufficient contact time before starting the clean up.
DISPOSAL: All wastes should be decontaminated before disposal either by steam sterilization, incineration or chemical disinfection.
STORAGE: The infectious agent should be stored in a sealed and identified container.
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: August 2010
PREPARED BY: Pathogen Regulation 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.
Public Health Agency of Canada, 2010