Klebsiella pneumonia is gram-negative bacteria and a common hospital-acquired pathogen, causing urinary tract infections, nosocomial pneumonia, and intraabdominal infections. K. pneumonia has high potential as a community-acquired pathogen. This article will talk about the characteristics of K. pneumonia and its contribution in causing community-acquired Klebsiella infection.
Klebsiella pneumonia is a gram-negative rod-shaped bacteria that is an important member of Klebsiella belonging to the genus Enterobacteriaceae. Even though, it is often implicated in hospital-acquired urinary tract and wound infections, it can cause pneumonia in people with weakened immune systems. It is posing a threat in hospitals as it is slowly developing its resistance to antibiotics.
The organism gets its name from a 19th century German microbiologist called Edwin Klebs. Klebsiellae are rod-shaped, gram-negative, non-motile bacteria with a defined polysaccharide capsule. Because of this capsule, these organisms appear large on samples stained with Gram Stain. K. pneumonia has the structural variability of the capsular polysaccharides (K antigens) and lipopolysaccharides (O antigens) and the serotypes are based on that. There are 8 O antigens and 77 K antigens and the virulence of all serotypes appears to be similar.
Klebsiellae are ubiquitous in nature and they may colonize the skin, pharynx, or gastrointestinal tract of humans. They have the tendency to even colonize sterile wounds and urine. Klebsiellae forms a part of the normal flora in many parts of the colon,intestinal tract and in the biliary tract.
K pneumonia and K oxytoca are the two members of this genus responsible for most human klebsiella infections. These opportunistic pathogens are found in the environment and in mammalian mucosal surfaces. The main pathogenic reservoirs of infection are the gastrointestinal tract of the patients and the hands of hospital staff. These organisms can spread rapidly leading to nosocomial outbreaks.
Klebsiella organisms infect the lungs by causing destructive changes like necrosis, inflammation, and hemorrhage of the lung tissue. Sometimes, they produce thick, bloody, mucoid sputum best described as currant jelly sputum. The illness, generally, affects the middle-aged and older men with debilitating diseases such as alcoholism, chronic bronchopulmonary disease or diabetes. This type of patient population usually has impaired respiratory host defenses that allow the organisms to gain access after the host aspirates, colonizing the oropharyngeal microbes and infecting the lower respiratory tract.
Klebsiellae causes nosocomial infections and the common sites of infections are urinary tract, lower respiratory tract, biliary tract, and surgical wound sites. The clinical syndromes that follows klebsiella infection includes pneumonia, bacteremia, thrombophlebitis, urinary tract infection (UTI), cholecystitis, diarrhea, upper respiratory tract infection, wound infection, osteomyelitis, and meningitis. Contamination of respiratory support equipment, presence of invasive devices, use of urinary catheters, and use of antibiotics are factors that increase the chances of nosocomial infection with Klebsiella species. The entry of the organism in the bloodstream can cause sepsis and septic shock.
Klebsiella species causes other infections like rhinoscleroma and ozena. These diseases occur rarely. Rhinoscleroma involves the nasopharynx, and is a chronic inflammatory process, whereas ozena is a chronic atrophic rhinitis and is characterized by necrosis of nasal mucosa and mucopurulent nasal discharge.
Community Acquired Pneumonia sometimes is presented after an episode of cold, flu, or any condition that gives access to bacteria to infect the airways. The symptoms of Community Acquired Pneumonia (CAP) may vary and are generally similar to that of common cold or flu. This variability in symptoms may sometimes make it difficult to recognize pneumonia. Many people assume the symptoms to be of difficult case of cold. However, if it is not diagnosed and treated well in time, CAP can pose a threat and could be fatal to life.
Some easily recognizable community acquired pneumonia symptoms are as follows:
In addition to the symptoms mentioned above, the following symptoms could be associated with this disease:
The diagnosis of the infection is done in two ways