We’d Love To help

Reach out to us we will get back to you

Preferable Time to Call


What Bacteria Causes Pink Eye? Know the Culprit Behind Bacterial Conjunctivitis

Gina Walters


what bacteria causes pink eye

Pink eye (or Conjunctivitis) is an infectious eye condition that leads to the swelling of the conjunctiva (tissue lining the inner eyelid). 

It is a highly contagious eye infection that can occur due to various factors, such as bacterial and viral infections.

Bacterial Conjunctivitis is prevalent in the U.S., occurring in around 135 per 10,000 individuals, according to BMC Ophthalmology.

But what bacteria causes pink eye? How do you identify the specific bacterial infection responsible for your symptoms?

This article explores the various bacterial infections that cause Conjunctivitis and compares their effects on the eyes. 

What is bacterial pink eye

As discussed, Bacterial Conjunctivitis (bacterial pink eye) is a condition that leads to the inflammation and infection of the conjunctiva. 

This thin, transparent membrane covers the white part of the eye and the inner surface of the eyelids.  

This type of pink eye primarily develops due to infections caused by bacterial pathogens. It is characterized by red eyes, irritation, and the formation of pus.

In addition, watery eyes, sensitivity to light, and swelling of the eyelids are common symptoms of bacterial pink eye. 

This condition is extremely contagious and spreads through direct or indirect contact with affected individuals or objects. 

A proper diagnosis and prescribed antibiotics are essential for effective treatment. 

Maintaining proper hygiene helps prevent its spread. This condition is common in adults and children, and prompt medical intervention is necessary.

Know which bacterias lead to Pink Eye with our article: What Bacteria Causes Pink Eye? Know the Culprit Behind Bacterial Conjunctivitis

Don’t compromise on eye health —- Find your perfect eye care product at GoodRxMedicine and see the benefits!
Order now: Eye Care

What bacteria causes pink eye

bacterial-pink-eye-treatmentSource: angeljana
Closeup of a woman suffering from Bacterial pink eye

The bacteria commonly responsible for the development of bacterial pink eye include Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae. 

In some cases, bacteria like Neisseria gonorrhoeae and Chlamydia trachomatis may also contribute to this infection. 

Let us discuss what bacteria causes pink eye in detail:

Want to know about the various causes of Pink Eye? Read our article: Uncovering Pink Eye Causes: A Comprehensive Guide

Staphylococcus aureus

Staphylococcus aureus is a common bacterium that may cause Bacterial Conjunctivitis in individuals who come into contact with it.

It can also cause various other infections, such as skin infections and abscesses. 

Pink eye caused by staphylococcus aureus typically results in symptoms like redness, swelling, and discharge from the eyes.

Streptococcus pneumoniae

Streptococcus pneumoniae, commonly known as pneumococcus, is responsible for respiratory infections such as Pneumonia and Sinusitis. 

However, in certain cases, it can also result in eye infections like Bacterial Conjunctivitis. 

According to research from 2010, it is the second-most leading cause of bacterial pink eye in children.

Conjunctivitis caused by streptococcus pneumoniae may have symptoms that are unique to this bacterium.

It often causes a thick, yellow, or greenish pink eye discharge, especially after sleep. It also causes redness, swelling, irritation, and blurry vision.

Know whether Pink Eye can cause blindness with our article: Can Pink Eye Cause Blindness? Exploring the Link Between the Two

Watch out for signs of worsening infection, like increasing pain, vision changes, or spreading redness.

Haemophiles influenzae

Haemophiles influenzae is commonly linked to respiratory tract infections, such as ear infections and Pneumonia. It is also a bacteria that causes pink eye in children.

However, as per a 2021 study, it is also the leading cause of Bacterial Conjunctivitis in children. 

Additionally, Conjunctivitis caused  due to Haemophilus influenzae has symptoms like bloodshot eyes, a watery pus-containing discharge, swelling, irritation, and blurred vision.

Understand why Pink Eye causes swelling with our article: Does Pink Eye Cause Swelling: Unraveling the Connection

Chlamydia trachomatis

Chlamydia trachomatis is an intracellular bacterium typically known for causing Sexually Transmitted Infections (STIs). 

In addition, it is also associated with the eye disease trachoma. 

This bacteria can cause neonatal Conjunctivitis in infants born to mothers with a chlamydial infection. This condition is commonly known as Chlamydial Conjunctivitis. 

In addition to the usual symptoms, such as redness and swelling, it also causes a mucopurulent discharge in the morning.

What is mucopurulent discharge? It is a liquid discharge containing mucus and pus.

Neisseria gonorrhoeae

Neisseria gonorrhoeae is a bacterium responsible for causing the Sexually Transmitted Infection (STI) known as Gonorrhea. 

If transmitted during childbirth, it can lead to a severe form of Bacterial Conjunctivitis in newborns called Gonococcal Conjunctivitis.

This type of pink eye can cause a thick pus-like discharge, severe redness and inflammation, pain and irritation, and blurry vision. Corneal ulcers may also be a potential symptom.

Recommended read: How do you know if you have bacterial pink eye? Get informed — What Are the Most Common Symptoms of Bacterial Pink Eye?

The bottom line

Bacterial pink eye is the inflammation of the conjunctiva that can occur due to various bacterial infections. 

But what bacteria causes pink eye? Understanding the bacteria responsible for your infection can help you seek appropriate treatment. 

Certain bacteria such as Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae are the most common bacterial pink eye causes.

In rare cases, the bacteria associated with STIs, like Chlamydia and Gonorrhea, can also cause Conjunctivitis. 

If you suspect you have Bacterial Conjunctivitis, consult a healthcare professional for accurate diagnosis and tailored treatment.

Recommended Article
Don’t suffer in silence – learn how to tackle bacterial pink eye today!
Read now: A Closer Look at Quick and Effective Bacterial Pink Eye Treatment

Frequently Asked Questions

What kind of bacteria causes bacterial pink eye?

Bacterial pink eye is primarily caused by bacteria like Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae, among others.

What causes bacterial pink eye in adults?

Bacterial pink eye in adults may result from contact with contaminated objects, inadequate hand hygiene, or exposure to infected individuals.

What bacteria causes pink eye and ear infections?

Bacteria such as streptococcus pneumoniae or Haemophilus influenzae can potentially cause Conjunctivitis and ear infections.

How do you get bacterial pink eye?

You can contract bacterial pink eye through direct or indirect contact with infected eye secretions or touching contaminated surfaces.

Will bacterial pink eye heal on its own?

While bacterial pink eye may heal without intervention, it is best to seek antibiotic treatment to speed up your recovery and minimize the chances of complications. It is advisable to seek guidance from a healthcare professional. 

When referencing outside resources, GoodrxMedicine always provides full citations. To learn more about the measures we use to maintain the quality of our content, please review our Content Information Policy.

More Articles Like This