MMSC 428 Exam 4 (Graded A+ Already)

CMI correct answers immune system response that is important for fighting off intracellular parasites (FIPs and OIPs), because once they are inside of the cells antibodies are not helpful mycobacterium characteristics correct answers -have a lot of hydrophobic myconic fatty acids in their cell wall, so they do not gram stain well -gram positive like bacilli -obligate aerobes -slow growers -colonies take 4-6 weeks to appear -produce dry, flat colonies with irregular filamentous edge that may produce orange or yellow carotenoid pigment -catalase + (measured with semiquantitative test) -have innate resistance to disinfectants and antimicrobial therapies due to slow growth and hydrophobic cell wall -show beading (irregular staining) and cording (clumped cells sticking together) in carbol fuschin stain -can be classified according to Runyun classification -MALDI-TOF, high pressure liquid chromatography (HPLC) MIDI, and NAAT are the best way to identify species -antibodies are detect with PPD skin test, active infections can be seen with chest X ray (granulomas) Mycobacterium tuberculosis clinical significance correct answers -most important member of the mycobacterium tuberculosis complex (MTBC) -causes tuberculosis (LRT infection) -bacteria cause a delayed type hypersensitivity response that causes overstimulation of the CMI, which causes the damage that is seen (not the bacteria) -bacteria are innately resistant to a lot of drugs and multi-drug resistant strains are appearing and making it more difficult to treat -most cases are seen in asia, africa and india -not seen a lot in the US, most cases are immigrants -vaccine is available (attenuated M. bovis) semiquantitative catalase test correct answers hydrogen peroxide is added to bacteria located in a test tube, and the height of the bubbles produced tells you approximately how much catalase enzyme is produced by the bacteria -used to differentiate the mycobacteria species mycobacterium tuberculosis correct answers -FIP that mainly infects monocytes and macrophages (latent infection) -most common mycobacterial infection in the world -causes respiratory infections -being a FIP is the most important virulence factor -gram positive-like cell wall that does not gram stain due to high myconic lipid content