Contents


**1**

**Figure 1.**

*Cell wall comparison according to Gram staining [2].*

**Chapter**

**Abstract**

60 min.

*Horacio Bach*

A New Era without Antibiotics

The appearance of multidrug-resistant bacteria is challenging the research community to find new antimicrobial agents. The problem is exacerbated because of the lack of new antibiotics and an uncontrolled use of antibiotics in the human and husbandry health. All these factors contributed to the development of more resistant pathogenic bacteria, which is alarming the health systems. In this chapter, the problems related to the lack of R&D in the development of new antibiotics in pharmaceutical companies as well as the misuse of antibiotics will be discussed. In addition, the new avenues of research in the development of new antimicrobial entities will be also examined.

**Keywords:** antibiotics, multidrug-resistant bacteria, antibiotic misuse, bacteriocins,

Bacteria are ubiquitous unicellular organisms able to adapt to the environmental changes in a very fast way. The double time of bacterial cells varies between 20 and

To visualize bacteria, a microscope is required. However, as a result of their transparency, their visualization is impaired unless a stain is used. In 1884, the Danish bacteriologist Hans C. Gram published a technique by which, bacterial cells can be divided into two groups according to their color after the staining [1]. Based on the staining remnant, bacteria are classified as Gram-positive (purple) and Gramnegative (pink). This separation is based on the ability of the Gram-positive bacteria to retain the dye crystal violet, according to their cell wall composition (**Figure 1**).

bacteriophages, antibacterial peptides, nanoparticles

**1. Brief overview of Bacteria**
