Gram Negative Cocco Bacilli.pptx

Gram negative cocci bacteria presentation.

1. Gram Negative Cocco Bacilli A  coccobacillus   is a type of bacterium with a shape intermediate between  cocci  (spherical bacteria) and bacilli (rod-shaped bacteria). They are nonmotile, non – spore forming, with complex nutritional growth requirements for blood-containing media.   Haemophilus (Haemophilus influenzae ), Bordetella (B. pertussis)   are Gram-negative coccobacillus responsible for causing whooping cough.  Yersinia pestis , the bacteria that causes plague, is also coccobacillus.

2. Haemophilus Haemophilus Influenzae are among the smallest of bacteria. The curved ends of the short (1.0 to 1.5 micro meter) bacilli makes many appear nearly round, hence the term coccobacilli . Sometimes occurring in pairs or short chains.

3. Haemophilus influenzae is found on the mucous membranes of the upper respiratory tract in humans . Haemophilus influenzae is aerobic bacteria. H. influenzae can be found in the normal nasopharyngeal flora of 20 to 80% of healthy persons. It is an important cause of meningitis in children and causes upper and lower respiratory tract infections in children and adults.

4. P athogenesis H. influenzae strains commonly found in the normal flora of the nasopharynx occasionally invade into deeper epithelial tissues. Bacteremia then leads to spread to the central nervous system and metastatic infections at distant sites such as bones and joints . These events seem to take place within a short period (less then 3 days) after an encounter with a new virulent strain. H . influenzae can be seen to invade between the cells of the respiratory epithelium. Localized infection: Such as the otitis media sinuses or bronchi.

5. Cont ,… Cellulitis: A tender, reddish-blue swelling in the cheek or periorbital areas is the usual presentation of cellulitis . Meningitis: H. Influenzae cause meningitis follows the same pattern as other causes of acute purulent bacterial meningitis. Epiglottitis : in which the inflamed epiglottis and surrounding tissues obstruct the airway. Also cause conjuctivitis

6. Lab Diagnosis Specimens consist of expectorated sputum and other types of respiratory specimens, pus, blood, and spinal fluid for smears and cultures depending on the source of the infection Direct Identification Commercial kits are available for immunologic detection of H influenzae antigens in spinal fluid. Culture On chocolate agar, flat , grayish brown colonies with diameters of 1–2 mm are present after 24 hours of incubation. The cultivation of Haemophilus species requires the use of culture media enriched with blood or blood products

7. Haemophilus need growth factor such as exogenous hematin and NAD, also know is growth factor V ( N icotinamide adenine dinucleotide (NAD) ) and X (hematin) are both present in erythrocytes. These factors are gain from blood when blood is heated (chocolate agar ). Gram Stain: G ram-negative cocco bacilli are observed.

8. H. influenzae : production of indole , and urease negative. Treatment H. influenzae is often susceptible in vitro to ampicillin and amoxicillin, and usually susceptible to the newer cephalosporins .