Proteus vulgaris

24h old culture
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gamma Proteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Proteus
Species:	P. vulgaris
Binomial name
Proteus vulgaris Hauser 1885

Proteus vulgaris is a rod-shaped, Gram negative bacterium that inhabits the intestinal tracts of humans and animals. It can be found in soil, water and fecal matter. It is grouped with the enterobacteriaceae and is an opportunistic pathogen of humans. It is known to cause urinary tract infections and wound infections.

The term Proteus signifies changeability of form, as personified in the Homeric poems in Proteus, "the old man of the sea," who tends the sealflocks of Poseidon and has the gift of endless transformation. The first use of the term “Proteus” in bacteriological nomenclature was made by Hauser (1885) who described under this term three types of organisms which he isolated from putrefied meat. One of the three species Hauser identified was Proteus vulgaris so this organism has a long history in Microbiology.

Over the past two decades the genus Proteus, and in particular P. vulgaris, has undergone a number of major taxonomic revisions. In 1982, P. vulgaris was separated into three biogroups on the basis of indole production. Biogroup one was indole negative and represented a new species: P. penneri; while biogroup two and three remained together as P. vulgaris.

Lab Identification

According to laboratory conducted fermentation tests, P. vulgaris ferments glucose and amygdalin, but does not ferment mannitol or lactose. P. vulgaris also tests positive for the methyl red (mixed acid fermentation) test and is also an extremely motile organism.

When P. vulgaris is tested using the API 20E Identification System [1] test strip for enterobacteriaceae (made by BIOMERIEUX) [2], it is discovered that it provides a positive result for: sulfur reduction, urease production, tryptophan deaminase production, and indole production, and provides a negative result for the remainder of the tests on the testing strip.

It is referenced in the Analytical Profile Index using the seven-digit code: 0474021

The optimal growing conditions of this organism is in a facultative anaerobic environment with an average temperature of about 37 degrees Celsius .

The Becton/Dickinson BBL Enterotube II system for identification of members of the family Enterobacteriaceae inoculated with Proteus vulgaris may yield the following results: Positive for Glucose fermentation (with gas production). Negative for Lysine and Ornithine. Positive for Hydrogen sulfide production and positive for Indole production. Negative for Adonitol and Lactose. Negative for Arabinose, Sorbitol and Dulcitol. The Phenylalanine test was positive as was the Harnstoff Urea test. Proteus vulgaris tested positive for Citrate. All combine for a "Biocode ID of 31407" for use in the Interpretation Guide/Computer Coding and Identification System (CCIS). Note that Proteus vulgaris can also test Urease negative in solid media (such as in Enterotube), but will be Urease positive in liquid media. The CCIS code will still identify Proteus vulgaris with a negative urease test.

Proteus Infections

Etiology & Epidemiology

• Nosocomial infections
• Proteus mirabilis causes 90% of Proteus infections.
• Proteus vulgaris and Proteus penneri are easily isolated from individuals in long-term care facilities and hospitals and from patients with underlying diseases or compromised immune systems.
• Patients with recurrent infections, those with structural abnormalities of the urinary tract, those who have had urethral instrumentation, and those whose infections were acquired in the hospital have an increased frequency of infection caused by Proteus and other organisms (e.g., Klebsiella, Enterobacter, Pseudomonas, enterococci, staphylococci)

Pathogenesis & Virulence

motility flagella

adherence factors
Fimbriae - facilitate adherence and thus enhance the capacity of the organism to produce disease

inflammatory response
IL-6/IL-8 secretion - attachment to uroepithelial cells initiates secretion apoptosis and epithelial cell desquamation pyelonephritis - Bacterial production of urease increases risk bacteremia & sepsis - bacterial endotoxin (LPS)

Survival urease production - alkalinize the urine by hydrolyzing urea to ammonia makes proteus effective in producing an environment in which it can survive.

Clinical Expression

Bacteremia & sepsis - Enterobacteriaceae (of which Proteus is a member) and Pseudomonas species are the microorganisms most commonly responsible for gram-negative bacteremia.

The presence of the sepsis syndrome associated with a UTI should raise the possibility of urinary tract obstruction. This is especially true of patients who reside in long-term care facilities, who have long-term indwelling urethral catheters, or who have a known history of urethral anatomic abnormalities.

UTI obstruction - Urease production leads to precipitation of organic and inorganic compounds, which leads to struvite stone formation. Struvite stones are composed of a combination of magnesium ammonium phosphate (struvite) and calcium carbonate-apatite. Struvite stone formation can be sustained only when ammonia production is increased and the urine pH is elevated to decrease the solubility of phosphate. Both of these requirements can occur only when urine is infected with a urease-producing organism such as Proteus. Urease metabolizes urea into ammonia and carbon dioxide: Urea 2NH3 + CO2. The ammonia/ammonium buffer pair has a pK of 9.0, resulting in the combination of highly alkaline urine rich in ammonia.

Symptoms attributable to struvite stones are uncommon. More often, women present with UTI, flank pain, or hematuria and are found to have a persistently alkaline urine pH (>7.0).

Treatments

Known antibiotics that P. vulgaris is sensitive to:

Ciprofloxacin
Ceftazidime
Netilmicin
Sulbactam or Cefoperazo
Meropenem
Piperacillin/tazobactam
Unasyn

Antibiotics should be introduced in much higher doses than "normal" when P. vulgaris has infected the sinus or respiratory tissues. I.E.- Ciprofloxacin should be introduced at a level of at least 2000 mg per day orally in such a situation, rather than the "standard" 1000 mg per day.

Sumber : http://en.wikipedia.org/wiki/Proteus_vulgaris

Klebsiella ozaenae

The genus Klebsiella belongs to the tribe Klebsiellae, a member of the family Enterobacteriaceae. The organisms are named after Edwin Klebs, a 19th century German microbiologist. Klebsiellae are nonmotile, rod-shaped, gram-negative bacteria with a prominent polysaccharide capsule. This capsule encases the entire cell surface, accounts for the large appearance of the organism on gram stain, and provides resistance against many host defense mechanisms.

Members of the Klebsiella genus typically express 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 contribute 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.^[1] 

This scanning electron micrograph (SEM) reveals some of the ultrastructural morphologic features of Klebsiella pneumoniae. Courtesy of CDC/Janice Carr.

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Pathophysiology

Host defense against bacterial invasion depends on phagocytosis by polymorphonuclear granulocytes and the bactericidal effect of serum, mediated in large part by complement proteins. Both classic-pathway and alternate-pathway complement activation have been described, but the latter, which does not require the presence of immunoglobulins directed against bacterial antigens, appears to be the more active pathway in K pneumoniae infections.

Recent data from preclinical studies suggest a role for neutrophil myeloperoxidase and lipopolysaccharide-binding protein in host defense against K pneumoniae infection. Neutrophil myeloperoxidase is thought to mediate oxidative inactivation of elastase, an enzyme implicated in the pathogenesis of various tissue-destroying diseases. Lipopolysaccharide-binding protein facilitates transfer of bacterial cell wall components to inflammatory cells. Investigators showed higher rates of infection in experimental mice deficient in the genes that control expression of these 2 agents.

The bacteria overcome innate host immunity through several means. They possess a polysaccharide capsule, which is the main determinant of their pathogenicity. The capsule is composed of complex acidic polysaccharides. Its massive layer protects the bacterium from phagocytosis by polymorphonuclear granulocytes. In addition, the capsule prevents bacterial death caused by bactericidal serum factors. This is accomplished mainly by inhibiting the activation or uptake of complement components, especially C3b. The bacteria also produce multiple adhesins. These may be fimbrial or nonfimbrial, each with distinct receptor specificity. These help the microorganism to adhere to host cells, which is critical to the infectious process.

Lipopolysaccharides (LPS) are another bacterial pathogenicity factor. They are able to activate complement, which causes selective deposition of C3b onto LPS molecules at sites distant from the bacterial cell membrane. This inhibits the formation of the membrane attack complex (C5b-C9), which prevents membrane damage and bacterial cell death.

Availability of iron increases host susceptibility to K pneumoniae infection. Bacteria are able to compete effectively for iron bound to host proteins because of the secretion of high-affinity, low molecular weight iron chelators known as siderophores. This is necessary because most host iron is bound to intracellular and extracellular proteins. In order to deprive bacteria of iron, the host also secretes iron-binding proteins.

Epidemiology

Klebsiellae are ubiquitous in nature. In humans, they may colonize the skin, pharynx, or gastrointestinal tract. They may also colonize sterile wounds and urine. Carriage rates vary with different studies. Klebsiellae may be regarded as normal flora in many parts of the colon and intestinal tract and in the biliary tract. Oropharyngeal carriage has been associated with endotracheal intubation, impaired host defenses, and antimicrobial use.

K pneumoniae and K oxytoca are the 2 members of this genus responsible for most human infections. They are opportunistic pathogens found in the environment and in mammalian mucosal surfaces. The principal pathogenic reservoirs of infection are the gastrointestinal tract of patients and the hands of hospital personnel. Organisms can spread rapidly, often leading to nosocomial outbreaks.

Infection with Klebsiella organisms occurs in the lungs, where they cause destructive changes. Necrosis, inflammation, and hemorrhage occur within lung tissue, sometimes producing a thick, bloody, mucoid sputum described as currant jelly sputum. The illness typically affects middle-aged and older men with debilitating diseases such as alcoholism, diabetes, or chronic bronchopulmonary disease. This patient population is believed to have impaired respiratory host defenses. The organisms gain access after the host aspirates colonizing oropharyngeal microbes into the lower respiratory tract.

Klebsiellae have also been incriminated in nosocomial infections. Common sites include the urinary tract, lower respiratory tract, biliary tract, and surgical wound sites. The spectrum of clinical syndromes includes pneumonia, bacteremia, thrombophlebitis, urinary tract infection (UTI), cholecystitis, diarrhea, upper respiratory tract infection, wound infection, osteomyelitis, and meningitis. The presence of invasive devices, contamination of respiratory support equipment, use of urinary catheters, and use of antibiotics are factors that increase the likelihood of nosocomial infection with Klebsiella species. Sepsis and septic shock may follow entry of organisms into the blood from a focal source.

Rhinoscleroma and ozena are 2 other infections caused by Klebsiella species. These diseases are rare. Rhinoscleroma is a chronic inflammatory process involving the nasopharynx, whereas ozena is a chronic atrophic rhinitis characterized by necrosis of nasal mucosa and mucopurulent nasal discharge.

K oxytoca has been implicated in neonatal bacteremia, especially among premature infants and in neonatal intensive care units. Increasingly, the organism is being isolated from patients with neonatal septicemia.

Extensive use of broad-spectrum antibiotics in hospitalized patients has led to both increased carriage of klebsiellae and, subsequently, the development of multidrug-resistant strains that produce extended-spectrum beta-lactamase (ESBL). These strains are highly virulent, show capsular type K55, and have an extraordinary ability to spread. Most outbreaks are due to a single clone or single gene; the bowel is the major site of colonization with infection of the urinary tract, respiratory tract, and wounds. Bacteremia and significant increased mortality have resulted from infection with these species.

In addition to prior antibiotic use, risk factors for infection include the presence of an indwelling catheter, feeding tube, or central venous catheter; poor health status; and treatment in an intensive care unit or nursing home. Acquisition of these species has become a major problem in most hospitals because of resistance to multiple antibiotics and potential transfer of plasmids to other organisms.

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Epidemiology

Frequency

United States

In some parts of the world, K pneumoniae is an important cause of community-acquired pneumonia in elderly persons. Studies conducted in Malaysia and Japan estimate the incidence rate in elderly persons to be 15-40%, which is equal to, if not greater than, that of Haemophilus influenzae. However, in the United States, these figures are different. Persons with alcoholism are the main population at risk, and they constitute 66% of people affected by this disease. Mortality rates are as high as 50% and approach 100% in persons with alcoholism and bacteremia.

Klebsiellae are also important in nosocomial infections among adult and pediatric populations. Klebsiellae account for approximately 8% of all hospital-acquired infections. In the United States, depending on the study reviewed, they comprise 3-7% of all nosocomial bacterial infections, placing them among the top 8 pathogens in hospitals. Klebsiellae cause as many as 14% of cases of primary bacteremia, second only to Escherichia coli as a cause of gram-negative sepsis. They may affect any body site, but respiratory infections and UTIs predominate.

Of 145 reported epidemic outbreaks of nosocomial bacteremias during 1983-1991, 13 were attributed to Klebsiella organisms. The US Centers for Disease Control and Prevention report that Klebsiella strains were responsible for 3% of all pathogenic epidemic outbreaks.

An investigation of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae among patients of acute and long-term acute care hospitals was conducted in 2011. The investigation found extensive spread of KPC-producing Enterobacteriaceae throughout 4 adjacent counties in Indiana and Illinois over a 1-yr period. Long-term acute care hospitals played a central role in the outbreak, suggesting that guidelines for controlling KPC should be expanded to include long-term care facilities. Education of personnel and coordinated regional efforts among health care facilities are crucial for KPC control.^[2]

K oxytoca is among the top 4 pathogens that cause infection in patients in neonatal intensive care units. It is the second most frequent cause of gram-negative neonatal bacteremia.

International

Outbreaks of neonatal septicemia occur worldwide. Infection with K pneumoniae also has a worldwide distribution. Infection with K rhinoscleromatis is not common in the United States, although it has a worldwide distribution and is usually observed in areas of eastern Europe, southern Asia, central Africa, and Latin America.

Mortality/Morbidity

• Klebsiella pneumonia is a necrotizing process with a predilection for debilitated people. It has a high mortality rate of approximately 50% even with antimicrobial therapy. The mortality rate approaches 100% for persons with alcoholism and bacteremia.
• Klebsiella bacteremia and sepsis produce clinical manifestations similar to those caused by other gram-negative enteric organisms. Morbidity and mortality rates are comparable to those for other gram-negative organisms that cause sepsis and septic shock. In neonatal units, outbreaks caused by ESBL-producing strains present a more serious problem and may be associated with increased mortality.

Age

• Community-acquired Klebsiella (Friedlãnder) pneumonia is a disease of debilitated middle-aged and older men with alcoholism.
• Nosocomial infections may affect adults or children, and they occur more frequently in premature infants, patients in neonatal intensive care units, and hospitalized individuals who are immunocompromised.

Sumber : http://emedicine.medscape.com/article/219907-overview#showall