We all have millions of bacteria in ourgastrointestinal tracts, primarily in the colon (or "large" bowel).These bacteria are important for normal bowel health and function. Klebsiella isthe genus name for one of these bacteria found in the respiratory, intestinal,and urinogenital tracts of animals and man. When Klebsiella bacteria get outside of the gut, however, seriousinfection can occur.
K. pneumoniae is second only to E. colias a urinary tract pathogen. Klebsiella infections are encountered far moreoften now than in the past. This is probably due to the bacterium's antibioticresistance properties.
Klebsiella pneumoniae is known as aresident of the intestinal track in about 40% of man and animals. It isconsidered to be an opportunistic human pathogen meaning that under certainconditions it may cause disease. For example, nosocomial infections are thosethat hospitalized patients pick up because they are in a weakened state1,2.
Klebsiella pneumoniae is also well knownin the environment and can be cultured from soil, water and vegetables. In fact,it is likely that we have K. pneumoniae in our intestine from eating raw foodssuch as salads. Two research papers on surveys of bacteria in sprouts found K.pneumoniae to be a predominant part of the microflora3. One research paper found 4% of the lettuce they tested containedKlebsiella pneumoniae4.
As a general rule, Klebsiella infectionstend to occur in people with a weakened immune system. Many of these infectionsare obtained when a person is in the hospital for some other reason. The mostcommon infection caused by Klebsiella bacteria outside the hospital ispneumonia.
Klebsiella pneumonia tends to affectpeople with underlying diseases, such as alcoholism, diabetes and chronic lungdisease. Classically, Klebsiella pneumonia causes a severe, rapid-onset illnessthat often causes areas of destruction in the lung.
Infected persons generally get highfever, chills, flu-like symptoms and a cough productive of a lot of mucous. Themucous (or sputum) that is coughed up is often thick and blood tinged and hasbeen referred to as "currant jelly" sputum due to its appearance.
Mortality in Klebsiella pneumonia isaround 50% due to the underlying disease that tends to be present in affectedpersons. While normal pneumonia frequently resolves without complication,Klebsiella pneumonia more frequently causes lung destruction and pockets of pusin the lung (known as abscesses). The mortality rate for untreated cases isaround 90%.
There may also be pus surrounding thelung (known as empyema), which can be very irritating to the delicate lungtissue and can cause scar tissue to form. At times, surgery may be needed to"rescue" a lung that is trapped in irregular pockets of pus and scartissue.
Klebsiella can also cause less seriousrespiratory infections, such as bronchitis, which is usually a hospital-acquiredinfection. Other common hospital-acquired infections caused by Klebsiella areurinary tract infections, surgical wound infections and infection of the blood.All of these infections can progress to shock and death if not treated early inan aggressive fashion.
Many hospital-acquired infections occurbecause of the invasive treatments that are often needed in hospitalizedpatients. For example, intravenous catheters used for fluid administration,catheters placed in the bladder for urine drainage and breathing tubes forpeople on a breathing machine can all increase the susceptibility to infection.
While these devices may be needed incertain patients, they allow bacteria to bypass the natural barriers toinfection and get into a person's body. The result may be an infection if theperson's immune system cannot fight the bacteria. Unfortunately, the peoplewho need invasive treatments often have weakened immune systems because of theirunderlying disease.
Klebsiella bacteria are a part of normallife and live inside almost all of us. Although it is something we generallydon't like to think about, we need Klebsiella in our colon to keep us healthy.Unfortunately, once Klebsiella escapes the gut, it can be one nasty bacterium.
Sproutsin Canada have been recalled because of the presence of Klebsiellapneumoniae, though there are no reported illnesses associated with sprouts.
None of the Klebsiella found on sprouts in Canada has been found to be pathogenic.5
Sproutgrowers have the opportunity, through seed sampling and testing, sanitizing, andpost testing, to produce the safest "leafy green vegetables" on the market.
1Eickhoff,T. C. 1972. Klebsiella pneumoniae infection: a review with reference to thewater-borne epidemiologic significance of K. pneumoniae presence in the naturalenvironment. national Council of the Paper Industry for Air and StreamImprovement, Inc. Technical Bulletin no. 254, New York, N.Y.
2Martin, W.J., P., K. W. Yu, and J. A. Washington. 1971. Epidemiological significance ofKlebsiella pneumoniae - a 3 month study. Mayo C.in. Proc. 46:785-793. 3) Selden,R., S. Lee, W. L. L. Wang, J. v. Bennett and T. C. Eickhoff. 1971. NosocomialKlebsiella infections: intestinal colonization as resevoir. Ann. Intern. Med.74:657-664.]
3J.E.Patterson, and M. J. Woodburn, 1980. Journal of food Science 45:492-495 and D.F. Splittstoesser, D. T. Queale & B. W. Andaloro. 1983. The microbiology ofvegetable sprouts during commercial production. Journal of Food Safety5:79-86.).
4Soriano JM,Rico H, Molto JC, Manes J., Int J Food Microbiol 2000 Jun 30;58(1-2):123-8,Assessment of the Microbiological Quality and Wash Treatments of Lettuce Servedin University Restaurants.
5Personal communication, Terry Peters, Health Canada.