Science Behind Superbug Infection
The Klebsiella genus is part of the Enterobacteriaceae family and are nonmotile, rod-shaped, gram negative bactaria with a major polysaccharide capsule which cover the entire cell surface providing protection against most host defense mechanisms.
Klebsiella genus generally display two types of antigens on the surface of the cell, lipopolysaccharide (O antigen) and capsular polysaccharide (K antigen), both contributing to pathogenicity.
Host defense against bacterial invasion is influenced by phagocytosis by polymorphonuclear granulocytes and the bactericidal result of serum, mainly mediated by complement proteins.
Studies and proteins
Preclinical studies imply a role for neutrophil myeloperoxidase and lipopolysaccharide-binding protein in host defense against K pneumoniae infection. Neutrophil myeloperoxidase is considered to mediate oxidative inactivation of elastase, an enzyme involved in the pathogenesis of different tissue destroying infections.
The bacteria defeat natural host immunity by various means, as they hold a polysaccharide capsule, which is the major determinant of their pathogenicity. The capsule’s huge layer provides protection from phagocytosis by polymorphonuclear granulocytes and avoids bacterial death from bactericidal serum factors. The numerous adhesins produced by the bacteria is responsible for the microorganism to hold on to host cells, which is crucial to the infectious process.
Klebsiellae are everywhere in nature, while in humans they can inhabit the skin, pharynx or gastrointestinal tract and also sterile wounds and urine.
Taxonomy and Prevention
K pneumoniae and K oxytoca are members of the genus that cause most human infections and they can found in the environment and in mammalian mucosal surfaces. The main pathogenic source of infections is the gastrointestinal tract of patients and the hands of hospital staff
Klebsiella infection takes place in the lungs, causing devastating changes and generally affects old or middle aged men with weakening diseases, such as diabetes or alcoholism.
Klebsiella have also been responsible for nosocomial infections in such sites as urinary tract, biliary tract, lower respiratory tract or surgical wound sites. Invasive apparatus, pollution of respiratory support equipment, urinary catheters and the use of antibiotics are also increasing the probability of nosocomial infection with various Klebsiella species.
Rhinoscleroma and ozena are two other rare infections set off by Klebsiella species.
The wide use of all-purpose antibiotics in hospitalized patients resulted in an amplified carriage of klebsiella and the appearance of multidrug-resistant strains. These strains are are very powerful and have an amazing ability to spread.
Besides previous antibiotic use, risk factors contributing to infection include indwelling catheter, feeding tube, venous catheter or weak health status. The acquisition of these species has become an important issue in numerous hospitals due to its resistance to several antibiotics and possible transfer of plasmids to various other organisms.
Occurrence of neonatal septicemia takes place worldwide while infection with K pneumoniae also occurs across the world. Although infection with K rhinoscleromatis is not frequent in the United States, it is generally observes is some areas of Eastern Europe, Southern Asia, Centra Africa and Latin America.
Klebsiella pneumonia has an increased mortality rate of roughly 50% even in the case of antimicrobial therapy. Even more, the mortality rate is close to 100% for people with alcoholism and bacteremia.