What is the Difference Between ESBL and CRE

Enterobacterales is an order of Gram-negative, non-spore forming, facultative anaerobic, rod-shaped bacteria. ESBL and CRE are two different Enterobacterale groups resistant to different antibiotics as they produce enzymes that breakdown antibiotics.

The key difference between ESBL and CRE is the type of antibiotic resistance they show. ESBL-producing Enterobacterales are resistant to penicillins and cephalosporins by producing ESBL enzymes, which break down these antibiotics. Similarly, CRE are Enterobacterales resistant to carbapenems by producing carbapenemase enzymes, which degrade carbapenem antibiotics.

CONTENTS

1. Overview and Key Difference
2. What is ESBL  
3. What is CRE
4. Similarities – ESBL and CRE
5. ESBL vs CRE in Tabular Form
6. Summary – ESBL vs CRE
7. FAQ: ESBL and CRE

What is ESBL?

ESBL are Enterobacterales resistant to penicillin and cephalosporin. This is because they produce an ESBL enzyme that breaks down the penicillin and cephalosporin antibiotics. However, ESBLs have no effect on carbapenems. Therefore, extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales may require complex treatments. Furthermore, infections caused by ESBL-producing Enterobacterales can occur both in and outside of healthcare settings.

Figure 01: Culture of ESBL-producing Escherichia coli

ESBL-producing Enterobacterales include germs like Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae). Furthermore, carbapenems often help to treat serious ESBL-producing Enterobacterales infections, but resistance is increasing for them, too.

What is CRE?

CRE or carbapenem-resistant enterobacterales are bacteria resistant to one or several antibiotics called carbapenems. Carbapenems antibiotics include ertapenem, imipenem, meropenem, and doripenem. CRE has caused about 13,100 infections in hospital patients and about 1,100 deaths in the United States. Examples of these Gram-negative bacteria are usually from the genera Klebsiella, Enterobacter, Citrobacter, Salmonella, Escherichia, Shigella, Proteus, and Serratia.

Figure 02: CRE

People who use medical devices such as ventilators, urinary (bladder) catheters, or intravenous catheters, those taking long courses of certain antibiotics, and individuals with weakened immune systems are at a higher risk of developing CRE infections. Furthermore, CRE infections are typically difficult to treat because they are resistant to most antibiotics, including carbapenems.

Similarities Between ESBL and CRE

• ESBL and CRE are two different Enterobacterale groups that show different antibiotic resistance.
• They are Gram-negative.
• Both are resistant to different antibiotics.
• Both are causing hospital-acquired infections.

Difference Between ESBL and CRE

Definition

1. ESBL are Enterobacterales that are resistant to penicillin and cephalosporins due to the production of ESBL enzymes, which break down these antibiotics.
2. CRE are Enterobacterales that are resistant to carbapenems due to the production of carbapenemase enzymes, which break down carbapenem antibiotics.

Examples

1. Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) are in ESBL Enterobacterales.
2. Klebsiella, Enterobacter, Citrobacter, Salmonella, Escherichia, Shigella, Proteus and Serratia are in CRE Enterobacterales.

Risk Factors

1. People who are in healthcare settings like hospitals and nursing homes and traveling home after visiting abroad are at greater risk of getting infections from ESBL.
2. People who require devices like ventilators, urinary (bladder) catheters, or intravenous catheters are taking long courses of certain antibiotics and have weakened immune systems, so they are at greater risk of getting infections from CRE.

Treatment

1. Carbapenems often help to treat serious ESBL-producing Enterobacterales infections.
2. CRE infections are difficult to treat as they are resistant to most antibiotics, including carbapenems.

The following table summarizes the difference between ESBL and CRE.

Summary – ESBL vs CRE

Enterobacterales are is a large family of bacteria and includes many familiar pathogens, such as Salmonella, Shigella, Klebsiella, and Escherichia coli. ESBL and CRE are two different Enterobacterale groups resistant to different antibiotics as they produce enzymes that break down the antibiotics. ESBL-producing bacteria are resistant to penicillins and cephalosporins due to the production of ESBL enzymes, which break down these antibiotics. In contrast, CRE is resistant to carbapenems by producing carbapenemase enzymes, which degrade carbapenem antibiotics such as ertapenem, imipenem, meropenem, and doripenem. This is the summary of the difference between ESBL and CRE.

FAQ: ESBL and CRE

1. What are the common bacteria in ESBL?

• There is a wide range of Gram-negative bacterial species of different families harboring ESBL genes. Among them, Escherichia coli is the most common host, followed by Klebsiella pneumoniae.

2. What is an ESBL infection?

• ESBL stands for extended spectrum beta-lactamase. It is an enzyme found in some strains of bacteria. The infections caused by these bacteria are known as ESBL-infections. ESBL producing bacteria can’t be killed by many of the antibiotics doctors use to treat infections such penicillins and some cephalosporins. This makes it harder to treat.

3. How to identify ESBL?

• ESBL group is usually identified by NDP test. Therefore, it is possible to identify ESBL group by using the ESBL Nordmann/Dortet/Poirel (NDP) test, which is based on the biochemical detection of the hydrolysis of the β-lactam ring of cefotaxime, a broad-spectrum cephalosporin.

4. What are examples of CRE bacteria?

• These Gram-negative bacteria are usually from the genera  Klebsiella, Enterobacter, Citrobacter, Salmonella, Escherichia, Shigella, Proteus, and Serratia are examples of CRE. Other bacteria can also become resistant to carbapenems, such as Acinetobacter and Pseudomonas.

5. How do you treat CRE bacteria?

• CRE infections can be hard to treat since common antibiotics don’t work against them. A provider may treat people with a different antibiotic or a carbapenem antibiotic with an added drug that will inhibit the bacteria’s carbapenemase. The drug prevent CRE from destroying the carbapenem.

Reference:

1. Husna, Asmaul, et al. “Extended-Spectrum β-Lactamases (ESBL): Challenges and Opportunities.” Biomedicines, U.S. National Library of Medicine.
2. “About Carbapenem-Resistant Enterobacterales.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention.

Image Courtesy:

1. “ESBL Stokes” By GrahamColm at English Wikipedia (CC BY-SA 3.0) via Commons Wikimedia

2. “18169 lores” By National Institute of Allergy and Infectious Diseases (NIAID) – (CC0) via Commons Wikimedia

Related posts:

Difference Between Agar Well and Disc Diffusion Method Difference Between Photosynthetic and Chemosynthetic Bacteria What is the Difference Between Candida and Malassezia What is the Difference Between Trichomonas and Gardnerella What is the Difference Between Bioburden and Microbial Limit Test