Common Pathogens

Methicillin Resistant Staphylococcus Aureus

MRSA has been featured in the news and on television programs a great deal recently. MRSA stands for Methicillin-resistant Staphylococcus aureus. This type of bacteria causes “staph” infections that are resistant to treatment with usual antibiotics.

Vancomycin Resistant Enterococcus

Enterococci are bacteria that are normally present in the human intestines and in the female genital tract and are often found in the environment. These bacteria can sometimes cause infections. Vancomycin is an antibiotic that is often used to treat infections caused by enterococci. In some cases, enterococci have become resistant to vancomycin and are called vancomycin-resistant enterococci or VRE. Most VRE infections occur in people in hospitals. VRE can live in the human intestines and female genital tract without causing disease (often called colonization). However, sometimes, it can be the cause of infections of the urinary tract, the bloodstream or of wounds.

Clostridium difficille

Clostridium difficile (klo-STRID-ee-um dif-uh-SEEL) is a bacterium that causes diarrhea and more serious intestinal conditions such as colitis. They are diseases that result from C. difficile infections such as Colitis, more serious intestinal conditions, sepsis, and rarely death.


Acinetobacter (ass in ée toe back ter) is a group of bacteria commonly found in soil and water. It can also be found on the skin of healthy people, especially health care personnel. While there are many types or “species” of Acinetobacter and all can cause human disease, Acinetobacter baumannii accounts for about 80% of reported infections. Outbreaks of Acinetobacter infections typically occur in intensive care units and health care settings housing very ill patients. Acinetobacter infections rarely occur outside of health care settings.

Extended Spectrum Beta Lactamase Producers

Extended-spectrum b-lactamase (ESBL)–producing gram-negative bacteria are emerging pathogens. Clinicians, microbiologists, infection control practitioners, and hospital epidemiologists are concerned about ESBL producing bacteria because of the increasing incidence of such infections, the limitations of effective antimicrobial drug therapy, and adverse patient outcomes.