Why Is It Called Chocolate Agar?

Why is blood agar used?

Many species of bacteria produce toxic by-products that are capable of destroying red blood cells.

Blood agar is a general purpose enriched medium often used to grow fastidious organisms and to differentiate bacteria based on their hemolytic properties..

Can you get sick from eating old chocolate?

Expired candy can also carry microbes that can make you sick. Aramouni, who studies food safety and food allergies in his lab, said that there have even been cases of salmonella poisoning from the consumption of old chocolate. … “Heat can cause many candies to melt and get too sticky,” Blakeslee said.

Why does Haemophilus influenzae 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.

Can bacteria grow in chocolate?

The pulp surrounding the cocoa beans is fermented by various microbes including yeasts, lactic acid bacteria, and acetic acid bacteria. The resulting high temperature and products produced by these microbes, such as the ethanol from yeast, kill the beans and contribute to the flavoring of the chocolate [2].

What bacteria does not grow on blood agar?

Blood agar is an enriched, bacterial growth medium. Fastidious organisms, such as streptococci, do not grow well on ordinary growth media. Blood agar is a type of growth medium (trypticase soy agar enriched with 5% sheep blood) that encourages the growth of bacteria, such as streptococci, that otherwise wouldn’t grow.

Where is Haemophilus influenzae found?

The one that people are most familiar with is H. influenzae type b or Hib. These bacteria live in people’s nose and throat, and usually cause no harm. However, the bacteria can sometimes move to other parts of the body and cause infection.

Is chocolate agar a selective medium?

Chocolate Agar supplemented with bacitracin is a selective medium used to improve the primary isolation of H. influenzae from specimens containing a mixed flora of bacteria and/or fungi.

What does chocolate agar contain?

Chocolate Agar consists of GC Agar Base with added hemoglobin and KoEnzyme Enrichment. GC Agar Base contains proteose peptone which provides nitrogenous nutrients. Hemoglobin releases hemin (X-factor) components. The phosphate buffer is added to maintain the pH of the medium.

What is the difference between blood agar and chocolate agar?

The composition of chocolate agar and the Blood Agar is the same and the only difference is while preparing chocolate agar, the red blood cells are lysed. … Neither of these species is able to grow on sheep blood agar. Chocolate agar slants are used for the short-term storage of pathogens such as N.

What grows MacConkey Agar?

MacConkey agar is a selective and differentiating agar that only grows gram-negative bacterial species; it can further differentiate the gram-negative organisms based on their lactose metabolism.

Can chocolate give you food poisoning?

Cadbury’s chocolate was the most likely cause of the salmonella outbreak that affected dozens of people earlier this year, the Government’s health watchdog said yesterday.

Is Haemophilus influenzae a virus or bacteria?

H influenzae meningitis is caused by Haemophilus influenzae type b bacteria. This illness is not the same as the flu (influenza), which is caused by a virus. Before the Hib vaccine, H influenzae was the leading cause of bacterial meningitis in children under age 5.

What type of bacteria grow on blood agar?

Blood Agar is used to grow a wide range of pathogens particularly those that are more difficult to grow such as Haemophilus influenzae, Streptococcus pneumoniae and Neisseria species. It is also required to detect and differentiate haemolytic bacteria, especially Streptococcus species.

Why do we use chocolate agar?

Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. … Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis. In addition, some of these bacteria, most notably H.

Is chocolate agar selective or differential?

Yellowing of chocolate agar was associated with alpha-hemolytic species of Streptococcus. The study demonstrated that reactions occurring on chocolate agar are useful in identifying gram-positive cocci. Chocolate agar, a differential medium for gram-positive cocci.

Does chocolate kill dogs?

In large enough amounts, chocolate and cocoa products can kill your dog. Why not chocolate? The toxic component of chocolate is theobromine. … With large amounts, theobromine can produce muscle tremors, seizures, an irregular heartbeat, internal bleeding or a heart attack.

What does Haemophilus influenzae look like?

Haemophilus influenzae is a small (1 µm × 0.3 µm), pleomorphic, gram-negative coccobacillus. Some strains of H influenzae possess a polysaccharide capsule, and these strains are serotyped into 6 different types (a-f) based on their biochemically different capsules. The most virulent strain is H influenzae type b (Hib).

Which Agar is both selective and differential?

MacConkey Agar. This medium is both selective and differential. The selective ingredients are the bile salts and the dye, crystal violet which inhibit the growth of Gram-positive bacteria.