Disease: CRE Bacteria Infection
(Carbapenem-Resistant Enterobacteriaceae)

    What is CRE?

    CRE (carbapenem-resistant Enterobacteriaceae) bacteria are members of related bacterial genera that are commonly found almost everywhere in the world, often colonizing humans and animals (living in or on humans and animals mucosal surfaces, gastrointestinal tracts, and on some areas on the skin). However, CRE possess a unique genetic makeup that allows the bacteria to make an enzyme that protect CRE bacteria from a powerful antibiotic: carbapenem. The most notable genera that can share and even transfer this genetic trait to other members of the Enterobacteriaceae are E. coli and Klebsiella pneumoniae. Because these bacteria generate similar problems for patients (especially treatment difficulties), most investigators simply group them together and term them CRE bacteria (some researchers term those bacteria that produce the enzyme carbapenemase CP-CRE bacteria). Similar types of components are termed KPC (Klebsiella pneumoniae carbapenemase) and NDM (New Delhi metallo-beta-lactamase).

    In February 2015, UCLA Ronald Regan Medical Center in California reported that two patients died and five others were infected with the drug-resistant superbug CRE. An additional 179 patients may have been exposed to the bacteria. These potential exposures to this bacterium likely came from contamination of an endoscope used to treat pancreaticobillary diseases at the facility.

    News agencies have presented short but eyebrow-raising comments made by the Centers for Disease Control and Prevention (CDC) about new and "dangerous" bacteria. The bacteria go by many names in the public press; "superbug 2013," "nightmare bacteria," and "dangerous bacteria" are some of the names. Unfortunately, most news stories have only a few minutes to explain a somewhat complicated situation involving genetics, bacterial adaptation to environmental pressures, and the impact on human populations that makes the CDC researchers, scientists, and doctors concerned. This article is designed to present readers with some further insights into these "dangerous" bacteria. The CDC name for these bacteria is CRE bacteria; the CRE stands for carbapenem-resistant Enterobacteriaceae.

    What causes CRE infections? How is CRE transmitted?

    This resistance to carbapenem is not the only reason CRE bacteria are considered dangerous. CRE bacteria that reach the bloodstream have a mortality (death) rate of 40%-50%. CRE are transmitted person to person, usually by direct contact with contaminated feces, skin, or instruments used in hospitals.

    How do CRE bacteria develop?

    The genetics of Enterobacteriaceae are complex; many genera and strains possess genetic material that codes for resistance against many types of antibiotics; unfortunately, as a strain develops resistance to an antibiotic, not only does it become resistant to that antibiotic, the genes that confer resistance to one antibiotic become linked to each other. Consequently, as different antibiotic resistance occurs, the genetic material can become linked together thus conferring antibiotic resistance to several antibiotics in a single bacterial strain. Such bacteria that are resistant to several antibiotics are considerably more dangerous to humans they may infect than are bacteria susceptible to antibiotics.

    As new antibiotics are introduced, they can pressure the bacteria to adapt to survive even the newest and most powerful ones; bacteria survive by allowing to replicate those few bacteria that develop stable resistance components that are genetically coded and then pass on genetic antibiotic resistance to other bacteria. Unfortunately, this new genetic ability is then again linked to other antibiotic-resistant genetic material, thus resulting in "dangerous" bacterial strains that are resistant to many, if not all, antibiotics. That is the current situation for CRE bacteria. Keep in mind that there are strains of CRE bacteria that can fairly easily transfer genetic information to other bacterial strains that do not have multiple drug resistance but may have the potential to be dangerous under certain circumstances (for example, enterotoxigenic E. coli).

    What are symptoms and signs of CRE infections?

    Symptoms of CRE infections vary with the infected organ system(s) (for example, kidney or flank pain with pyelonephritis, fevers, or pain and pus production in wound infections). Nevertheless, these symptoms can also be caused by non-CRE infections. There are no specific symptoms of CRE infections; however, there are problems that can develop that make physicians suspicious that CRE infections may be the cause of symptoms. They include the following:

    • isolating organisms that show resistance to antibiotic therapy,
    • severe pneumonia,
    • severe urinary tract infection,
    • high fever,
    • sepsis,
    • septic shock.

    How do doctors diagnose a CRE infection?

    Doctors diagnose CRE (and other antibiotic-resistant superbugs) by blood tests called blood cultures. These blood cultures contain the bacteria responsible for infection. To demonstrate whether the organism is antibiotic resistant, a test is done called a drug sensitivity. An antibiotic-resistant superbug is one whose growth is not markedly inhibited in the presence of several antibiotics, one of which is carbapenem. PCR (polymerase chain reaction) tests may also be done to determine which type of bacterium is causing the patient's infection.

    What is the treatment for CRE infections?

    Treatment of CRE infections is difficult. Some doctors may choose a combination of antibiotics that show some ability to kill or inhibit CRE bacteria from growing. Antibiotics such as aminoglycosides, polymyxins, tigecycline (Tygacil), fosfomycin (Monurol), and temocillin have been used with some success to treat CRE infections. Infectious-disease experts should be consulted if an individual is diagnosed with a CRE infection.

    Learn more about: Tygacil | Monurol

    Is it possible to prevent a CRE infection?

    Currently, outbreaks of CRE bacteria are small. However, it may not remain that way. The CDC and other researchers know that many strains of Enterobacteriaceae can be deadly and difficult to treat even without being resistant to most antibiotics (for example, E. coli 0157:H7). How much damage could E. coli do to humans if it became a CRE bacterium by genetic transfer and retained its current pathogenic characteristics? Researchers and the CDC do not want to see this happen.

    In addition, when a patient becomes infected with a CRE bacterium, the death rate is 40%-50%, even with multiple antibiotic treatments and supportive measures. With additional pathogenic traits (easy person-to-person transfer, the ability to synthesize toxins such as enterotoxins) added to the ability to be resistant to most, if not all, antibiotics, the bacteria could devastate large populations of people. Since there are very few drug companies developing new antibiotics, the survival advantage may tip in favor of the bacterial pathogens, not to the infected people being treated with antibiotics.

    Because recent CRE outbreaks have been small and often confined to hospital intensive-care units, nursing homes, and other treatment areas where the use of new and powerful antibiotics is most frequent, the CDC has developed an attack method to keep CRE and other similar bacteria away from the general population and to reduce the "dangerous" bacteria's chances for survival and passage from these areas. The detailed method is described in the reference below and all health-care workers are urged to participate to prevent widespread outbreaks of CRE and similar bacteria. An abbreviated version of the CDC recommendations is as follows:

    Summary of Prevention (of CRE Infections) Strategies for Acute and Long-Term Care Facilities (CDC 2012)Core Measures for All Acute and Long-Term Care Facilities

    1. Hand hygiene

    • Promote hand hygiene
    • Monitor hand hygiene adherence and provide feedback
    • Ensure access to hand hygiene stations

    2. Contact precautions

    Acute care

    • Place CRE colonized or infected patients on Contact Precautions (CP)
      • Preemptive CP might be used for patients transferred from high-risk settings
    • Educate healthcare personnel about CP
    • Monitor CP adherence and provide feedback
    • No recommendation can be made for discontinuation of CP
    • Develop lab protocols for notifying clinicians and IP (Inpatients or Hospitalized patients) about potential CRE

    Long-term care

    • Place CRE colonized or infected residents that are high-risk for transmission on CP (as described in text); for patients at lower risk for transmission use Standard Precautions for most situations

    3. Patient and staff cohorting (grouping)

    • When available group (cohort) CRE colonized or infected patients and the staff that care for them even if patients are housed in single rooms
    • If the number of single patient rooms is limited, reserve these rooms for patients with highest risk for transmission (for example, incontinence)

    4. Minimize use of invasive devices

    5. Promote antimicrobial stewardship

    6. Screening (screening for CRE bacterial strains in patients and in high acuity areas, for example, intensive care units and isolation rooms used for patients with infections)

    The CDC further recommends that patients identified with CRE infections should be bathed with 2% chlorhexidine and that areas that house or treat CRE-infected patients undergo strict decontamination treatments. Instruments that may be in contact or used to diagnose or treat CRE-infected patients should also undergo rigorous decontamination. The instruments used at UCLA were decontaminated, but now the hospital has instituted even more stringent decontamination protocols.

    What causes CRE infections? How is CRE transmitted?

    This resistance to carbapenem is not the only reason CRE bacteria are considered dangerous. CRE bacteria that reach the bloodstream have a mortality (death) rate of 40%-50%. CRE are transmitted person to person, usually by direct contact with contaminated feces, skin, or instruments used in hospitals.

    How do CRE bacteria develop?

    The genetics of Enterobacteriaceae are complex; many genera and strains possess genetic material that codes for resistance against many types of antibiotics; unfortunately, as a strain develops resistance to an antibiotic, not only does it become resistant to that antibiotic, the genes that confer resistance to one antibiotic become linked to each other. Consequently, as different antibiotic resistance occurs, the genetic material can become linked together thus conferring antibiotic resistance to several antibiotics in a single bacterial strain. Such bacteria that are resistant to several antibiotics are considerably more dangerous to humans they may infect than are bacteria susceptible to antibiotics.

    As new antibiotics are introduced, they can pressure the bacteria to adapt to survive even the newest and most powerful ones; bacteria survive by allowing to replicate those few bacteria that develop stable resistance components that are genetically coded and then pass on genetic antibiotic resistance to other bacteria. Unfortunately, this new genetic ability is then again linked to other antibiotic-resistant genetic material, thus resulting in "dangerous" bacterial strains that are resistant to many, if not all, antibiotics. That is the current situation for CRE bacteria. Keep in mind that there are strains of CRE bacteria that can fairly easily transfer genetic information to other bacterial strains that do not have multiple drug resistance but may have the potential to be dangerous under certain circumstances (for example, enterotoxigenic E. coli).

    What are symptoms and signs of CRE infections?

    Symptoms of CRE infections vary with the infected organ system(s) (for example, kidney or flank pain with pyelonephritis, fevers, or pain and pus production in wound infections). Nevertheless, these symptoms can also be caused by non-CRE infections. There are no specific symptoms of CRE infections; however, there are problems that can develop that make physicians suspicious that CRE infections may be the cause of symptoms. They include the following:

    • isolating organisms that show resistance to antibiotic therapy,
    • severe pneumonia,
    • severe urinary tract infection,
    • high fever,
    • sepsis,
    • septic shock.

    How do doctors diagnose a CRE infection?

    Doctors diagnose CRE (and other antibiotic-resistant superbugs) by blood tests called blood cultures. These blood cultures contain the bacteria responsible for infection. To demonstrate whether the organism is antibiotic resistant, a test is done called a drug sensitivity. An antibiotic-resistant superbug is one whose growth is not markedly inhibited in the presence of several antibiotics, one of which is carbapenem. PCR (polymerase chain reaction) tests may also be done to determine which type of bacterium is causing the patient's infection.

    What is the treatment for CRE infections?

    Treatment of CRE infections is difficult. Some doctors may choose a combination of antibiotics that show some ability to kill or inhibit CRE bacteria from growing. Antibiotics such as aminoglycosides, polymyxins, tigecycline (Tygacil), fosfomycin (Monurol), and temocillin have been used with some success to treat CRE infections. Infectious-disease experts should be consulted if an individual is diagnosed with a CRE infection.

    Learn more about: Tygacil | Monurol

    Is it possible to prevent a CRE infection?

    Currently, outbreaks of CRE bacteria are small. However, it may not remain that way. The CDC and other researchers know that many strains of Enterobacteriaceae can be deadly and difficult to treat even without being resistant to most antibiotics (for example, E. coli 0157:H7). How much damage could E. coli do to humans if it became a CRE bacterium by genetic transfer and retained its current pathogenic characteristics? Researchers and the CDC do not want to see this happen.

    In addition, when a patient becomes infected with a CRE bacterium, the death rate is 40%-50%, even with multiple antibiotic treatments and supportive measures. With additional pathogenic traits (easy person-to-person transfer, the ability to synthesize toxins such as enterotoxins) added to the ability to be resistant to most, if not all, antibiotics, the bacteria could devastate large populations of people. Since there are very few drug companies developing new antibiotics, the survival advantage may tip in favor of the bacterial pathogens, not to the infected people being treated with antibiotics.

    Because recent CRE outbreaks have been small and often confined to hospital intensive-care units, nursing homes, and other treatment areas where the use of new and powerful antibiotics is most frequent, the CDC has developed an attack method to keep CRE and other similar bacteria away from the general population and to reduce the "dangerous" bacteria's chances for survival and passage from these areas. The detailed method is described in the reference below and all health-care workers are urged to participate to prevent widespread outbreaks of CRE and similar bacteria. An abbreviated version of the CDC recommendations is as follows:

    Summary of Prevention (of CRE Infections) Strategies for Acute and Long-Term Care Facilities (CDC 2012)Core Measures for All Acute and Long-Term Care Facilities

    1. Hand hygiene

    • Promote hand hygiene
    • Monitor hand hygiene adherence and provide feedback
    • Ensure access to hand hygiene stations

    2. Contact precautions

    Acute care

    • Place CRE colonized or infected patients on Contact Precautions (CP)
      • Preemptive CP might be used for patients transferred from high-risk settings
    • Educate healthcare personnel about CP
    • Monitor CP adherence and provide feedback
    • No recommendation can be made for discontinuation of CP
    • Develop lab protocols for notifying clinicians and IP (Inpatients or Hospitalized patients) about potential CRE

    Long-term care

    • Place CRE colonized or infected residents that are high-risk for transmission on CP (as described in text); for patients at lower risk for transmission use Standard Precautions for most situations

    3. Patient and staff cohorting (grouping)

    • When available group (cohort) CRE colonized or infected patients and the staff that care for them even if patients are housed in single rooms
    • If the number of single patient rooms is limited, reserve these rooms for patients with highest risk for transmission (for example, incontinence)

    4. Minimize use of invasive devices

    5. Promote antimicrobial stewardship

    6. Screening (screening for CRE bacterial strains in patients and in high acuity areas, for example, intensive care units and isolation rooms used for patients with infections)

    The CDC further recommends that patients identified with CRE infections should be bathed with 2% chlorhexidine and that areas that house or treat CRE-infected patients undergo strict decontamination treatments. Instruments that may be in contact or used to diagnose or treat CRE-infected patients should also undergo rigorous decontamination. The instruments used at UCLA were decontaminated, but now the hospital has instituted even more stringent decontamination protocols.

    Source: http://www.rxlist.com

    Treatment of CRE infections is difficult. Some doctors may choose a combination of antibiotics that show some ability to kill or inhibit CRE bacteria from growing. Antibiotics such as aminoglycosides, polymyxins, tigecycline (Tygacil), fosfomycin (Monurol), and temocillin have been used with some success to treat CRE infections. Infectious-disease experts should be consulted if an individual is diagnosed with a CRE infection.

    Learn more about: Tygacil | Monurol

    Source: http://www.rxlist.com

    Health Services in

    Define Common Diseases

    Senior Healthcare Matters helps you find information, definitaions and treatement options for most common diseases, sicknesses, illnesses and medical conditions. Find what diseases you have quick and now.