A superbug is a term used in the lay-media to describe a strain of bacteria that is resistant to most prescribed antibiotics. These emerging strains of bacteria can be pretty frightening, since treatments for infection are usually very limited. Keep reading to find out which kinds of infectious bacteria have developed antibiotic resistance and are now considered Superbugs.
What are Some Emerging Superbugs?
Methicillin-resistant Staphylococcus aureus (MRSA)
Staphylococcus aureus (or informally referred to as “Staph”) manifests itself in many ways, but is probably most famously known as “flesh-eating bacteria”. About 25% to 30% of the general population is colonized with Staph in their nose or on the surface of their skin, but if it finds its way beyond the skin barrier, it can cause a variety of infections, ranging from minor skin infections, including pimples or boils, to more serious infections that can lead to fatal outcomes, such as pneumonia or sepsis.
For many years, penicillin and methicillin were considered excellent treatments for Staph infections. Strains of Staph that are resistant to methicillin were first observed in hospitals and other healthcare facilities. However, in recent years, community-associated MRSA has become more prevalent. A recent article in JAMA estimated that in 2005, MRSA infected nearly 9,000 Americans, in whom 1 in 5 infections were deadly.
Drug-resistant tuberculosis (MDR- and XDR-TB)
Tuberculosis, also known as “consumption”, is a horrific wasting disease that is acquired by inhalation into the lungs, where it can cause disease (pulmonary tuberculosis), but can spread to other organs in the body, resulting in various presentations (meningitis, Pott's Disease, etc.). Prior to the discovery of antibiotics, tuberculosis was untreatable. However, even with the widespread use of antibiotics that began in the 1940s, multidrug-resistant tuberculosis (MDR-TB) has emerged and is a leading cause of death, particularly among HIV-infected individuals. MDR-TB is caused by strains of Mycobacterium tuberculosis that are resistant to at least the antibiotics isoniazid and rifampicin. A subset of MDR-TB, extensively drug-resistant tuberculosis (XDR-TB), is caused by rare strains that are resistant to isoniazid and rifampicin, as well as second-line (or follow-up) medications. Both MDR- and XDR-TB are rare in the U.S., but individuals with HIV are at greatest risk for getting infected.
Enterococcus faecalis and Enterococcus faecium are found in the bowel and female genital tract and can cause urinary tract infections, blood infections, and meningitis. Enterococci can cause fatal infections in individuals with compromised health, such as infants and the elderly. Several strains of drug-resistant enterococci have emerged in the last 30 years, including those that are resistant to penicillin, vancomycin, and linezolid.
Drug-resistant Streptococcus pneumoniae
Streptococcus pneumoniae is a common cause of ear infections in children, meningitis, systemic infection, and pneumonia. Strains that are resistant to penicillin and other penicillin-like antibiotics have increased over the last 30 years and are responsible for a large percentage of death and sickness in the U.S.
Antibiotic resistance is being detected in many different bacterial species at alarming rates. Other bacterial strains with reported antibiotic resistance include, but are not limited to, Pseudomonas aeruginosa (an “opportunistic pathogen” that infects immunocompromised individuals), Streptococcus pyogenes (another species of flesh-eating bacteria and the cause of strep throat, impetigo, and scarlet fever) and Proteus vulgaris (a cause of many urinary tract infections).
Community-Associated MRSA Information for the Public. CDC. 11 August 2008
Klevens, R. Monina, et al. ”Invasive Methicillin-Resistant Staphylococcus aureus Infections in the United States”. JAMA 2007 298:1763-1771. 30 July 2008.
Fact Sheet. Multidrug-Resistant Tuberculosis (MDR TB) . Division of Tuberculosis Elimination. CDC. 11 August 2008
Fact Sheet. Extensively Drug-Resistant Tuberculosis (XDR TB) . Division of Tuberculosis Elimination. CDC. 11 August 2008
Hyucke, Mark M, Daniel F. Sahm, and Michael S. Gilmore ”Multiple-Drug Resistant Enterococci: The Nature of the Problem and an Agenda for the Future”. Emerging Infectious Diseases Apr-Jun 1998 4:239-249. 30 July 2008.