Question

Discuss most common bacterial Reproduction method ,defined generation Time and the concept of relation between Microbial generation time and incubation period for a disease to developed

Answer 1

Most common bacterial reproduction method is binary fission. It is an asexual reproduction method . The organism divides into two, each part carrying one copy of genetic material. When bacterial cell reaches a certain size, it devides to form two daughter cells. Nuclear division proceeds the cell division and each new organism carrying a copy of DNA. The cell divides by a constructive or pinching process , or by the ingrowth of a transverse spectrum across the cell.

Steps in binary fission.

1. Chromosome replication

Here the DNA become uncoiled and replicates it's chromosome.

2. Cell growth

Bacterial cells grow in size. Increase in cytoplasmic content occur , the two strands of DNA migrate opposite poles of the cell.

3. Segregation of DNA

The cell elongate with a septum at the middle of the cell and two chromosomes are seperate.

4. Splitting of Cells

The cell splits into two, after the formation of a new cell wall.

Generation Time.

The interval time between two cell divisions , or the time required for a bacterium to give rise to two daughter cells under optimum conditions is known as the generation time or population doubling time.

The increase in bacterial population is like a geometrical progression.

Incubation period

Incubation period is the time interval between invasion by the infectious agent and appearance of the first sign or symptom of the disease in question.

In epidemiological perspective generation time is the interval of time between the receipt of infection by a host and maximum infectivity of that host. Entry of the organism and it's maximum multiplication inside the host.

General generation time and incubation periods are roughly equal, but not the same. The time between maximum communicability may precede or follow the incubation period. Generation time refers to the transmission of infection, whether clinical or sub clinical but incubation period can only applied to infections that results in manifestation of the disease( signs and symptoms.).