What organism requires X and V factor for growth?
H. influenzae is a fastidious organism which grows best at 35-37°C with ~5% CO2 (or in a candle-jar) and requires both X factor and V factor for growth.
What is X factor and V factor in microbiology?
The X factor (hemin) is needed for synthesis of cytochrome C and other iron-containing respiratory enzymes. The V factor (NAD and NADP) is required for reduction-oxidation (redox) processes in the cell metabolism.
What is the X factor in microbiology?
X factor comprises protoporphyrin IX, also called haemin or other iron-containing porphyrins. These are required for growth because X-dependent strains are unable to convert d-aminolaevulinic acid to protoporphyrin. They are heat stable.
Which Haemophilus species require both X and V factors for growth?
Haemophilus influenzae requires both factors X and V; accordingly, it grows on chocolate agar but not on blood agar (Fig. 30-2), although it may appear on a blood agar plate as tiny satellite colonies around the colonies of other bacteria that have lysed red blood cells.
Which of the bacteria shows phenomenon of Satellitism?
Staphylococcus aureus produces NAD as a metabolic byproduct when growing in a culture media containing blood. Therefore, Haemophilus spp may grow on sheep blood agar very close to the colonies of Staphylococcus aureus (as it produces NAD-factor V); this phenomenon is known as satelliting.
Why does Haemophilus influenzae only grow on chocolate agar?
Growth occurs on a CAP because NAD is released from the blood during the heating process of chocolate agar preparation (the heating process also inactivates growth inhibitors) and hemin is available from non-hemolyzed as well as hemolyzed blood cells. Alternatively, NAD can be included as a component of liquid H.
What is Satellitism?
Medical Definition of satellitism : the growth of bacteria of one type in culture about colonies of another type that supply needed micronutrients or growth factors.
Does H. influenzae grow on MacConkey?
Haemophilus spp. do not grow on MacConkey agar. Haemophilus influenzae has been shown to cause invasive infection such as meningitis and there is direct spread from water droplets from the upper respiratory tract of infected individuals. The development of the H. influenza type B vaccine has decreased mortality.
What does Haemophilus influenzae require for growth?
H. influenzae is a fastidious organism which grows best at 35-37°C with ~5% CO2 (or in a candle-jar) and requires hemin (X factor) and nicotinamide-adenine-dinucleotide (NAD, also known as V factor) for growth.
What is Satellitism phenomenon?
[sat´ĕ-li-tizm] the phenomenon in which certain bacterial species grow more vigorously in the immediate vicinity of colonies of other unrelated species, owing to the production of an essential metabolite by the latter species.
What is Satellitism in regards to the genus Haemophilus?
What are the characteristics of X and V growth factors?
They are heat stable. V factor comprises nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP). They are heat labile. However, different species of Haemophilus have varying requirements for X and V growth factors.
What is the difference between X Factor and V factor?
X factor indicates hemin and V factor indicates nicotinamide-adenine-dinucleotide, NAD. Consequently, the significant differences in growth factor requirements of Haemophilus spp. allows for their differentiation. Haemophilus spp are small, pleomorphic, gram-negative bacilli or coccobacilli with random arrangements.
What is the difference between X and V growth factors in Haemophilus?
Haemophilus spp. have varying requirements for X and V growth factors. X factor indicates hemin and V factor indicates nicotinamide-adenine-dinucleotide, NAD. Consequently, the significant differences in growth factor requirements of Haemophilus spp. allows for their differentiation. Haemophilus spp are small, pleomorphic,
Does growth around the XV disk require X or V factor?
Growth around the XV disk only shows a requirement for both factors. Growth around the V disk, no growth around the X disk, and light growth around the XV disk shows a V factor requirement. Negative test: Growth over the entire surface of the agar indicates no requirement for either X or V factor.