Legionella & Mycoplasma Dr.Qurat-Ul-Ain Senior Demonstrator Microbiology,KEMU, Lahore
Laboratory Diagnosis Specimens – throat swabs, respiratory secretions. Microscopy – Highly pleomorphic, varying from small spherical shapes to longer branching filaments. 2. Gram negative, but better stained with Giemsa,Dienes’ stain, crystal-fast violet, orcein or fluorochroming with nucleic acid stain as acredine orange
Laboratory Diagnosis Isolation of Mycoplasma (Culture) – Semi solid enriched medium containing 20% horse or human serum, yeast extract & DNA. Penicillium & Thallium acetate are selective agents. (serum – source of cholesterol & other lipids) 2. Incubate aerobically for 7 -12 days with 5–10% CO2 at 35-37°C. (temp range 22- 41°C, parasites 35- 37°C, saprophytes – lower temp)
Identification of Isolates Growth Inhibition Test – inhibition of growth around discs impregnated with specific antisera. Immunofluorescence on colonies transferred to glass slides. Molecular diagnosis PCR-based tests are being developed and these are expected to be the diagnostic test of choice in the future. These should have good sensitivity and be specific
Identification of Isolates Serological diagnosis Specific tests – IF, HAI 2. Non specific serological tests – cold agglutination tests (Abs agglutinate human group O red cells at low temperature, 4C). 1:32 titer or above is significant.