Lab Gülfem hoca

• identify organism specific antibodies in the patient´s serum -> use known antigens

or

• identify the microorganism in patient -> use known antibody (more common)

• Slide/Tube Agglutination test

  • dilution of patients serum + standard bacterial suspension

  • f.e. typhoid fever

Titer of antibody

• Slide Agglutination

  • f.e. Salmonella & Shigella (directed against their cell wall O antigen

• Latex Aggl.

  • use Latex beat coated with antibodies

  • f.e. Cryptococcus neoforman (capsular antigen) -> meningitis

• ELISA

  • Enzyme Linked ImmunoSorbent Assay

• Fluorescence Antibody Test

  • label antibody with fluorescence dye

• sterile tissues, CSF, joint fluid, urine

• use Gram or acid fast stain

• sputum sample -> assess whether pneumonia by gram staining (pos.) -> if active tuberculosis suspected acid fast stain

• get CSF -> negative Gram stain -> start treatment because meningitis medical emergency

  -> perform acid fast stain if acute meningitis is suspected -> f.e. tuberculosis visible

  -> perform CSF culture for nucleic acid amplification methods

3 tubes (Microscopic exam., Microbiological culture, protein & glucose measurement)

• shape

• size

• arrangement

• stain -> type

• how many bacteria types present?

• bacteria or fungi

• streak specimen onto appropriate media & cultured under appropriate condition (aerobic or anaerobic) -> isolated colonies needed

• selective, only allows growth of certain bacteria (MacConkey/ESB, Shigella)

or

• distinguish due to biochemical reaction (Blood agar)

  
  

sample on blood agar media -> blood agar media contains RBC -> color changes if bacteria in sample that produce enzymes causing hemolysis -> different types of hemolysins detected (alpha, beta or gamma)

• contains Gram negative rods

• inhibit Gram positive bacteria growth and differentiates between lactose fermenters and non-fermenters

  -> e.coli lactose f. -> dark & green

  -> Salmonella & Shigella nonl. f. -> colorless

• ESB (used in Turkey)

• sepsis

• endocarditis

• osteomyelitis

• meningitis

• pneumonia

1. 2 bottles of blood (10ml) -> 1 aerobically & 1 anaerobically incubated -> bottle with organism growth shows CO2 production

2. Gram stain, subculture & antibiotic sensitivity testing with right bottle

children when streptococcus infection

• don´t touch mouth (microbiota interferes with pathogen growth)

• rub surface of both tonsils, tonsillar pillars & posterior pharyngeal wall

• blood agar plate used

• pneumonia or active pulmonary tuberculosis

• take sputum with minimal salive (>25 leukocytes &<10 epithelial cells per 100× field)

  -> in inturbated patients tracheal aspirate, bronchoalveolar lavage or lung biopsy

• severe, bloody or chronic diarrhea (for longer than 4 weeks and/or more than 200gr per day)

• ISP

• outbreak

• healthcare assoc. diarrhea

  
  

• process in lab within 2 hours

• pyelonephritis or cystitis

• wash external orfice & midstream used

• unsterile cup (microscope), sterile (culture)

  -> culture within 1 hour (or refrigerate for max. 18h at 4°C)

• 100 000 per ml (asymptomatic)

• if specimen taken via catheter or if symptomatic 1 000 per ml

• female: cervix and/or anal canal

  male: urethral canal and/or anal canal

• nucleic acid techniques, microscopy, culture or serology

• risk of infertility in women if fallopian tubes get damaged

• infections often polymicrobial (depending on site and predisposing factor)

• often anaerobes (esp. in diabetic patients) BUT bc polymicrobial culture under different conditions

• due to treponema pallidum -> doesn´t grow on lab media -> antibody detection needed (appears uniformly distributed if positive)

• confirming is important therefore multiple tests

• Cold agglutinin test -> autoimmune antibodies of patients aggl. at 4°C but not bdy temperature

  -> false positives because not only in pneumonia

• NAATs (Nucleic Acid Amplification Tests)

  • PCR to incr. number of specific DNA/RNA mol

• NAATs (Nucleic Acid Amplification Tests)

• Nucleic acid probes

• Nucleic acid sequence analysis

• robust, highly-specific, sensitive, faster than culture

• measures particles based on mass to charge ratio (in 4 min)

• only bacteria and some fungi

recognize foreign nucleic acids in a specific sequence and eliminate them by using endonucleases (CRISPR Cas enzyme)