Gram-Positive and Gram-Negative Bacteria: The Differences Explained

Gram-Positive and Gram-Negative Bacteria: The Differences Explained

Gram-Positive and Gram-Negative Bacteria

When it comes to bacteria, not all are created equal. There are two major categories of bacteria, gram-positive and gram-negative. While both types pose a potential risk to human health, understanding the difference between them can help you make better decisions about how to protect yourself from harm. Let’s take a closer look at these two categories of bacteria and how they differ from one another. 

Distinguishing the Characteristics 

The most easily identifiable difference between gram-positive and gram-negative bacteria is that gram-positive bacteria have thicker cell walls than gram-negative bacteria. This means that they are more resistant to antibiotics, which can make treating infections caused by these types of bacteria difficult. On the other hand, gram-negative bacteria have thinner cell walls, making them easier to treat with antibiotics. 

Another distinguishing characteristic is that gram-positive bacteria usually form clusters when viewed under a microscope, while gram-negative bacteria tend to appear as single cells or in pairs. This makes it easier for researchers and doctors alike to identify the type of bacteria present in a sample.  

Gram staining is an important tool used in determining whether a particular bacterial strain is gram positive or negative; this test involves applying specific dyes to the sample, which causes different results based on the type of cell wall present in the bacterium being studied. 

The following information will provide more of an overview on Gram-positive and Gram-negative bacteria:

Gram-positive bacteria

Color after bram testing = blue or purple

Cell wall thickness = thick

Toxins include:

• emetic toxin
• diarrheal enterotoxins
• neurotoxins
• enterotoxin


• Staphylococcus aureus
• Staphylococcus epidermidis
• Staphylococcus saprophyticus
• Streptococcus pneumoniae
• Streptococcus pyogenes
• Streptococcus agalactiae
• Enterococci
• Corynebacterium diphtheriae
• Bacillus anthracis

Gram-negative bacteria

Color after gram testing = pink or red

Cell wall thickness = thin


• endotoxins


• Vibrio cholerae
• Escherichia coli
• Bartonella henselae
• Campylobacter
• Legionella
• Salmonella
• Salmonella typhi

Health Implications

Both gram-positive and gram-negative bacteria can cause serious illnesses if left untreated; however, each type has its own unique set of associated risks. Gram-positive bacterial infections tend to be less severe but more widespread than those caused by their gram-negative counterparts; they also tend to cause more long term damage due to their resistance to antibiotics. On the other hand, infections caused by gram negative bacteria can be more severe but are typically localized rather than systemic (affecting the entire body). In either case, it’s important that these types of infections be treated quickly and properly in order to avoid further complications down the line. 

The Bottom Line on Gram-Positive and Gram-Negative Bacteria

Although gram positive and gram negative bacteria are two distinct categories of infectious agents with different characteristics and health implications for humans. It’s important for people to understand these differences so they can make informed decisions about how best to prevent infection by either type of bacterium. Knowing what you’re up against when it comes to bacterial skin infection will go a long way toward helping you stay healthy!

If you work in healthcare, then please consider using Vitastem Ultra to treat a variety of bacterial skin infections. Vitastem is an FDA-registered drug and one of the world’s strongest topical antibiotics. Vitastem Ultra quickly kills all harmful Gram-positive and Gram-negative bacteria that have been available for testing (bacteria that is associated with eczema, psoriasis, acne scars, diabetic wounds, cuts, and others) along with antibiotic-resistant bacteria like MRSA (flesh-eating bacteria) and staph infection too.