NAME: Mycoplasma spp. (excluding M. hominis , M. genitalium , M. pneumoniae)
SYNONYM OR CROSS REFERENCE: Mycoplasmas, pleuropneumonia-like organism (PPLO), L-form(Footnote 1)
CHARACTERISTICS: Mycoplasmas are ubiquitous intracellular pleomorphic gram negative bacteria, which belong to the family Mycoplasmataceae , in the Mollicutes class (Footnote 2,Footnote 3) . Most are motile, using gliding motility instead of pili or flagella(Footnote 4,Footnote 5). They are the smallest organism capable of self replication (0.2 to 2 µm in diameter), and they lack the genes coding for the cell wall, leading them to a parasitic and saprophytic existence(Footnote 6). Instead of a cell wall, they possess a three-layered membrane, containing sterol, which is taken up from the environment. Most are facultative anaerobic, but some are strictly anaerobic. In Mycoplasmas, the UGA codon codes for tryptophan rather than being a Stop codon(Footnote 7). Mycoplasmas may metabolize glucose or arginine, but not urea.
PATHOGENICITY/TOXICITY: Mycoplasmas (except M. pneumoniae) are usually commensal respiratory and urogenital tract inhabitants, but they can become pathogenic(Footnote 4). M. orale and M. salivarium , usually commensals of the oro-pharynx, may be found in the lower respiratory tract of patients with chronic bronchitis, although it is not clear that they have an effect on severity of bronchitis(Footnote 2). M. salivarium has been found in a biofilm of an occluded biliary stent and is implicated in periodontal disease(Footnote 8,Footnote 9). This pathogen may also cause arthritis in cases of hypogammaglobulinemia(Footnote 4). M. fermentans is a co-factor of HIV and may cause lung and brain infection in AIDS patients(Footnote 10). M. fermentans is also detected in patients with inflammatory arthritic disorders, gulf war syndrome. It may implicated in the chronic fatigue syndrome but it is unclear, since other reports have infirmed that. It has been detected in adults suffering from an acute influenza-like illness, sometimes progressing rapidly to an often-fatal respiratory distress syndrome, proving that this pathogen is not always opportunistic(Footnote 2). The prevalence of infection with mycoplasmas is probably underestimated, because they are often contaminants of cell cultures and are usually ignored(Footnote 10).
EPIDEMIOLOGY: These pathogens are prevalent worldwide(Footnote 3). Immunocompromised, agammaglobulinemia suffering patients and patients taking immunosuppressive drug are particularly at risk.
HOST RANGE: 16 species are known to colonize humans(Footnote 3). M. orale and M. salivarium may also colonize non-human primate. M. fermentans have been found in genital infections of sheep. Other animals can be hosts, depending on the species.
INFECTIOUS DOSE: Unknown.
INCUBATION PERIOD: Days to months depending of bacterium(Footnote 2).
COMMUNICABILITY: Since most human mycoplasmas are considered part of the normal human flora, their communicability is unknown(Footnote 2).
RESERVOIR: Almost all animals may contain mycoplasmas(Footnote 3).
VECTORS: Deer ticks (Ixodes scapularis) have been reported to be a vector for M. fermentans(Footnote 11).
DRUG SUSCEPTIBILITY: Mycoplasmas are susceptible to tetracycline, macrolides, and lincosamides, and they are all resistant to penicillins and rifampin(Footnote 4).
SUSCEPTIBILITY TO DISINFECTANTS: Phenolic disinfectants, 1% sodium hypochlorite, 70% ethanol, formaldehyde, glutaraldehyde, iodophore, and peracedic acid are effective against Mycoplasma spp .(Footnote 13) .
PHYSICAL INACTIVATION: Mycoplasma spp. are inactivated by UV, microwave, gamma radiation, moist heat (121°C for at least 20 min) and dry heat (165-170°C for 2 h)(Footnote 14,Footnote 15,Footnote 16,Footnote 17).
SURVIVAL OUTSIDE HOST: If protected from evaporation, Mycoplasma spp . can survive for one hour in liquid specimen(Footnote 18).
SURVEILLANCE: Monitor for symptoms. Diagnosis can be confirmed with microbial culture and PCR(Footnote 18).
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Give appropriate drug therapy(Footnote 4).
IMMUNIZATION: Vaccines are used in animals (e.g. cattle, goat, sheep, pigs, and poultry), but none are currently available for humans(Footnote 19).
PROPHYLAXIS: None available.
SOURCES/SPECIMENS: Mycoplasmas may be found in blood, synovial fluid, urine, oro- pharynx, lower respiratory tract, bronchoalveolar lavage, amniotic fluid, cerebrospinal fluid, prostatic secretion, semen, wound aspirate, sputum, pleural fluid, swabs from naso-pharynx, cervix, vagina, wounds, urethra placenta, endometrium, bone chip, and urinary calculi, depending on the species and clinical conditions(Footnote 18).
PRIMARY HAZARDS: Laboratory workers should pay attention to droplets exposure of mucous membrane, infectious aerosol, parenteral inoculation, and ingestion(Footnote 18). Infections may also be transmitted by laboratory animals(Footnote 20,Footnote 21).
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk Group 2(Footnote 22). This risk group classification applies to the genus as a whole, but may not be representative of 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. 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 slashes, and respirator should be used when exposed to infectious aerosols(Footnote 23).
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(Footnote 23). Additional precautions should be considered with work involving animals or large scale activities.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (30 min)(Footnote 23).
DISPOSAL: All material should be decontaminated before disposal with steam sterilization, incineration or chemical disinfection(Footnote 23).
STORAGE: Samples and biological material should be store in appropriately labelled sealed containers(Footnote 23).
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: September 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