Upper and Lower Respiratory Tract Infection

Upper Respiratory Tract Infection “Throat Swab”

Throat swap culture First step : Breath deeply. Second step: open mouth widely& push the tongue out& phonate “AAHHH”

Third step: insert the cotton swap through the mouth and rotate on the area of tonsil or both tonsil.

5th step: transport the specimen to the lab as soon (avoid dry) 4th step: remove the cotton swap from the mouth, avoid touch the tongue, teeth… 5th step: transport the specimen to the lab as soon (avoid dry)

6th step take the swap under sterile condition, rotate it on the first quadrant of blood agar plate

7th step # then do the streaking method by loop and stab it few times, then incubate at 37 c / 24 h. # Search for hemolytic ß hemolytic: Clear zone. Streptolysin S Streptolysin O (v. imp)

Streptococcus pyogenes Colonies of Streptococcus pyogenes on sheep blood agar. Notice: * Presence of b hemolysis around colonies * Enhanced hemolysis around stabbing sites * Sensitivity to bacitracin (Disk A)

Streptococcus pyogenes Pin point colony: (white or gray) Gram stain: G+ve, cocci, single chain. Catalase enzyme: differentiate between Streptococcus –ve Staphylococcus +ve

Streptococcus pyogenes Antibiotic susceptibility of S. pyogenes. Bacitracin Sensitive Optochin Resistance

Haemophilus influenzae G-ve, blood lover, fastidious M.O. need: X factor heme extra & intracellular. V factor NAD intracellular. Best media Choclate

Haemophilus influenzae G-negative coccobacilli, typical of H. influenzae Grayish mucoid colonies of H. influenzae on chocolate agar  

Haemophilus influenzae Shows phenomena Satellitism: growth on blood agar near a line of Staphylococcus aureus.

Haemophilus influenzae

Lower Respiratory Tract Infections Sputum Examination: Sputum: Trachiobroncial secretions, visco-elastic (95% water and only 5% solids) as it comes out, it is contaminated by nasal and salivary secretions and normal bacterial flora of the oral cavity.

Specimen collection In case of Adult: 1- mouth should be pre-rinsedremove contaminants. 2- first morning specimen, Good specimen <10 epith and >25 WBCs.

In case of children Nasopharyngeal swab. Cough Swab method. 1- the child mouth is held open by using tongue depressor. 2- Epiglottis is visualized and is touched with swab to induce cough.

3- Material expelled deposited on the swab and cultured in three different media. * Blood media. * Chocolate. * MacConcy.

Macroscopic Examination Consistency and Appearance. normal sputum is clear and watery. Color of Sputum: Normal color is clear and colorless.in case of infections

Color of Sputum yellow (indicates pus and epithelial cells)=pneumonic+ Staphylococcus aureus.  Green (pseudomonas)== Otitis.  Red (blood) TB.

Microscopic Examination Mycobacterium tuberculosis Acid fast bacilli

Mycobacterium tuberculosis Culture on Lowenestein-Jensen media. Yellowish colony on green background

Streptococcus pneumoniae Lancet-shaped, G-positive diplococci, typical of S. pneumoniae

a hemolysis on 5% sheep blood agar, S. pneumoniae a hemolysis on 5% sheep blood agar, typical of S. pneumoniae. Sensitivity to optochin is also demonstrated

Klebsiella pneumoniae Colonies of Klebsiella pneumoniae on MacConkey agar, showing lactose fermentation and mucoid appearance

IMViC reaction of K. pneumoniae: - - + +

Pseudomonas aeruginosa Greenish discoloration of media due to production of pyocyanin by Pseudomonas aeruginosa

Pseudomonas aeruginosa Results of oxidase test

Corynebacterium diphtheriae G+ve non motile, pleomorphic rod. Formation of pseudomembrane covering the mouth & pharynx. Can be severe and sometimes fatal disease.

Paragonimus westermani Adult worm in the lung. Hermaphrodite (both sex)

Paragonimus westermani Eggs in sputum : diagnostic stages.

Paragonimus westermani

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