The bacterial culture is performed on agar plates and preferably the chocolate agar is added with hemin and nicotinamide adenine dinucleotide factors at 37 degree celcius in a CO2 enriched incubator. Blood agar growth is only achieved as a satellite phenomenon around other bacteria. Colonies of H.influenza appears as convex, smooth, pale, grey or transparent colonies.
The cultured organisms shows catalase and oxidase test positive. Serological testing is necessary to distinguish the capsules polysaccharide and differentiate between H.influenza b and non encapsulated species.
Although highly specific, bacterial culture of H. influenzae lacks sensitivity. Use of antibiotics prior to sample collection greatly reduces the isolation rate by killing the bacteria before identification is possible. Beyond this, H. influenzae is a finicky bacterium to culture, and any modification of culture procedures can greatly reduce isolation rates. Poor quality of laboratories in developing countries has resulted in poor isolation rates of H. influenzae
The bacteria will grow in the hemolytic zone of staphylococcus aureus on blood agar plates. The bacterium will not grow outside the hemolytic zone of S. aureus due to lack of nutrients. Flides agar is the best for the isolation of the bacteria. In Levinthal medium, the capsulated strains shows distinctive iridescence.
Latex particle agglutination:
The latex particle agglutination test is a more sensitive metho to detect H.influenzae than in culture. Because this method relies on antigen rather than viable bacteria. The antibiotic sensitivity testing is not possible with latex agglutination test alone and hence parallel cultivation of the bacteria is also indicated.
Polymerase chain reaction (PCR) assays have been proven to be more sensitive than either LAT or culture tests, and highly specific. However, PCR assays have not yet become routine in clinical settings. Countercurrent immunoelectrophoresis has been shown to be an effective research diagnostic method but has been largely supplanted by PCR.
The chest x ray predicts any abnormal area in the lungs
It reveals the slice of the lung. It uses both the combination of x ray and computer aided device.
It helps to analyse the size, shape and position of any lung tumour and also it helps in the detection of enlarged lymph nodes.
It also looks for any masses in the adrenal gland, liver, brain and other organs.
CT guided needle Biopsy:
CT scan might be used to guide a biopsy needle into this area to get the tissue for lung and further investigations are made.
It uses the soft tissue image of the organ. It uses the both the magnet and radiowaves and aids in the view of soft tissues of the internal organs.
Immunosorbent assay- detect the specific IgM or IgG antibodies.
Lumbar puncture or spinal tap:
The fluid is drawn from the spinal cord and further investigations are made.