Let's evaluate each of the statements for accuracy:

(A) Colostrum is recommended for the new born because it is rich in antigen.

This statement is partially correct but is somewhat misleading. Colostrum, the first form of milk produced by mammals immediately following delivery of the newborn, is indeed recommended for newborns, but not merely because it is rich in antigens. It contains a variety of beneficial components like antibodies (especially IgA), growth factors, and nutrients. The antibodies are crucial for passive immunity which protects the infant from infections during the early days of life. Therefore, the rationale behind recommending colostrum is not just because it is 'rich in antigen' but because it contains antibodies and other immune components essential for the newborn's defense.

(B) Chikungunya is caused by a Gram-negative bacterium.

This statement is false. Chikungunya is not caused by a bacterium at all; rather, it is a viral disease caused by the Chikungunya virus, which is transmitted to humans by mosquitoes, namely Aedes aegypti and Aedes albopictus. The categorization of bacteria as Gram-negative or Gram-positive is based on their cell wall composition and staining properties, which are irrelevant to viruses like the Chikungunya virus.

(C) Tissue culture has proved useful in obtaining virus-free plants.

This statement is true. Tissue culture techniques can be used to produce virus-free plants by culturing tissues from plants that are infected with a virus, and then using a technique called meristem culture, which often results in the production of new, virus-free plants. This is an important practice in agriculture and horticulture for maintaining the health and productivity of crops.

(D) Beer is manufactured by distillation of fermented grape juice.

This statement is false. Beer is usually made from the fermentation of cereal grains, primarily barley, although other grains can be used. The production of beer involves malting, mashing, boiling, fermenting, conditioning, filtering, and packaging. Distillation is not a part of the beer brewing process; it is a process used in the production of spirits. Furthermore, fermented grape juice results in wine, not beer.

Considering the above explanations: statement (B) is unquestionably wrong; statement (D) is also wrong; and, while statement (A) contains an element of truth, the wording is misleading and could be considered incorrect for the purpose of this question. Therefore, it is reasonable to conclude that:

Three out of the four given statements are wrong, which corresponds with Option D: Three.