Final answer:
In the early stages, a bacterial infection on the nail plate is identified as a yellow green spot, resulting from different bacteria that cause discoloration and brittleness of the nail, which is primarily made of keratin.
Step-by-step explanation:
In the early stages, a typical bacterial infection on the nail plate can be identified as a yellow green spot. This is because various types of bacteria, including opportunistic pathogens like Candida albicans, can cause discoloration and other changes in the appearance of the nails. For instance, fungal infections such as tinea unguium, which can be caused by dermatophytes or Candida species, result in the nail becoming yellow, brittle, and prone to breaking. Observing the characteristics of the infection, such as color and texture, can help in the preliminary identification of the pathogen.
The nail plate, which is the portion that is external to the skin, can be visibly affected during an infection. Nails are mainly composed of a protein called keratin, and recognizing changes in the nail plate can be an important indicator of a potential infection. Infections that progress can also lead to nail deformities and possibly separation of the nail, among other symptoms, but the early stage is most commonly identified by the discoloration referenced above.