Klebsiella+pneumoniae

**__Backgroun d __**
The genus //Klebsiella// belongs to the group Klebsiellae, which is a member of the Enterobacteriaceae family. Named after German microbiologist Edwin Klebs in the 19th century. Klebsiellae is a nonmotile, rod-shaped, gram-negative bacterium with a prominent polysaccharide capsule. This capsule covers the entire cell surface, which accounts for the large appearance of the organism on a gram stain, and provides resistance against many host defense mechanisms. Members of the //Klebsiella// genus typically exhibit 2 types of antigens on their cell surface. The first is a lipopolysaccharide (O antigen); the other is a capsular polysaccharide (K antigen). Both of these antigens give way to pathogenicity. About 77 K antigens and 9 O antigens exist. The structural variability of these antigens forms the basis for classification into various serotypes. The virulence of all serotypes appears to be similar. The genus was originally divided into 3 main species based on biochemical reactions. Today, 7 species with demonstrated similarities in DNA homology are known. These are (1) //Klebsiella pneumoniae,// (2) //Klebsiella ozaenae,// (3) //Klebsiella rhinoscleromatis,// (4) //Klebsiella oxytoca,// (5) //Klebsiella planticola,// (6) //Klebsiella terrigena,// and (7) //Klebsiella ornithinolytica//. //K pneumoniae// is the most medically important species of the group. //K oxytoca// and //K rhinoscleromatis// have also been demonstrated in human clinical specimens. In recent years, klebsiellae have become important pathogens in nosocomial infections.



__Cell Structure__
Klebsiella pnuemoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium.

__**Methods of identification**__
There are three different strains of Klebsiella pneumoniae on Endo agar with biochemical slope (see here). Klebsiella pneumoniae is urea positive (blue color of the slope), metabolise glucose with production of gas (bubbles under a piece of glass - in detail left down side of each plate) and is lactose positive (but on Endo agar its colonies often remain quite pale). Unlike some similarly looking strains of Enterobacter cloacae is K. pneumoniae lysine "+", ornithine "-", arginine "-" (E. cloacae lysine "-", ornithine "+", arginine "+").

**__BASIC TESTS FOR IDENTIFICATION__**
MacConkey growth+ Indole production- Methyl red- Voges-Proskauer+ Citrate(Simmons)+ Hydrogen sulfide(TSI)- Urea hydrolysis+ Lysine decarboxylase+ Arginine dihydrolase- Ornithine decarboxylase- Motility (36 °C)- D-glucose acid/gas+/+ D-mannitol fermentation+ Sucrose fermentation+ Lactose fermentation+ D-sorbitol fermentation+ Cellobiose+ Esculin hydrolisis+ Acetate utilizationD ONPG test+

**__Infectious Disease__** Klebsiella Pneumoniae is found in the normal flora of the mouth, skin, and intestines. It is clinically the most important member of the Klebsiella genus of Enterobacteriaceae. It naturally occurs in the soil and about 30% of strains can fix nitrogen in anaerobic condition. As a general rule, Klebsiella infections tend to occur in people with a weak immune system from improper diet (alcoholics and diabetics). Many of these infections are obtained when a person is in the hospital for some other reason (a nosocomial infection). The most common infection caused by Klebsiella bacteria outside the hospital is pneumonia. New antibiotic resistant strains of K. pneumoniae are appearing, and it is increasingly found as a nosocomial infection.Klebsiella ranks second to E. coli for urinary tract infections in older persons. It is also an opportunistic pathogen for patients with chronic pulmonary disease, enteric pathogenicity, nasal mucosa atrophy, and rhinoscleroma. Feces are the most significant source of patient infection, followed by contact with contaminated instruments.

**__How Klebsiella bacteria are spread__**
To get a Klebsiella infection, a person must be exposed to the bacteria. For example, Klebsiella must enter the respiratory (breathing) tract to cause pneumonia, or the blood to cause a bloodstream infection. In healthcare settings, Klebsiella bacteria can be spread through person-to-person contact (for example, from patient to patient via the contaminated hands of healthcare personnel, or other persons) or, less commonly, by contamination of the environment. The bacteria are not spread through the air. Patients in healthcare settings also may be exposed to Klebsiella when they are on ventilators (breathing machines), or have intravenous (vein) catheters or wounds (caused by injury or surgery). Unfortunately, these medical tools and conditions may allow Klebsiella to enter the body and cause infection.

**__Preventing Klebsiella from spreading__**
To prevent spreading Klebsiella infections between patients, healthcare personnel must follow specific infection control precautions (see: Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings 2007). These precautions may include strict adherence to hand hygiene and wearing gowns and gloves when they enter rooms where patients with Klebsiella–related illnesses are housed. Healthcare facilities also must follow strict cleaning procedures to prevent the spread of Klebsiella.

**__To prevent the spread of infections, patients also should clean their hands very often, including:__**
Before preparing or eating food Before touching their eyes, nose, or mouth Before and after changing wound dressings or bandages After using the restroom After blowing their nose, coughing, or sneezing After touching hospital surfaces such as bed rails, bedside tables, doorknobs, remote controls, or the phone

**__Drug-resistant Klebsiella__**
Some Klebsiella bacteria have become highly resistant to antibiotics. When bacteria such as Klebsiella pneumoniae produce an enzyme known as a carbapenemase (referred to as KPC-producing organisms), then the class of antibiotics called carbapenems will not work to kill the bacteria and treat the infection. Klebsiella species are examples of Enterobacteriaceae, a normal part of the human gut bacteria, that can become carbapenem-resistant. CRE, which stands for carbapenem-resistant Enterobacteriaceae, are a family of germs that are difficult to treat because they have high levels of resistance to antibiotics. Unfortunately, carbapenem antibiotics often are the last line of defense against Gram-negative infections that are resistant to other antibiotics.

**__Treating Klebsiella infections__**
Klebsiella infections that are not drug-resistant can be treated with antibiotics. Infections caused by KPC-producing bacteria can be difficult to treat because fewer antibiotics are effective against them. In such cases, a microbiology laboratory must run tests to determine which antibiotics will treat the infection.

__**The following video is a creative and informative sketch of a Klebsiella and some other bacteria.**__
media type="youtube" key="IY5KPRc6nj0" width="420" height="315"


 * Duration:** (8:25)
 * User:** SketchyMicro

__**REFERENCES:**__
__[]__ [] [] [|http://www.cdc.gov/HAI/organisms/klebsiella/klebsiella.html#a8]