Introduction
To the genre Proteus belong three species of high pathological interest: Proteus penneri, Proteus mirabilis and Proteus vulgaris; these bacteria are involved in various infections, especially of a nocosomal nature and affecting the urinary tract.
Microbiological description
Among the virulence factors, we remember the endotoxins, the flagella (which confer mobility and anchorage to the ureters in urinary infections) and the pili (able to adhere to the epithelia).
Microorganisms belonging to the genus Proteus they usually populate soil, fertilizers and sewage. Except for the species P. Rettgeri And P. morganii, very many strains of Proteus they carry out an acid-mixed fermentation and produce generous quantities of H2S (hydrogen sulphide).
Bacteria of the genus Proteus they are sensitive to moist heat and dry heat. Outside the host, the bacilli Proteus they survive for a day or two on inanimate surfaces, although they can easily replicate in soil, water and sewers.
Proteus infections
Although they behave as commensal microorganisms of the human intestinal tract, the bacilli of the genus Proteus they can cause harm when they spread to other locations. In fact, once in the urinary tract, the bacillus can cause local infection: a subject appears more sensitive to these infections when his defenses are no longer sufficient to protect the organism from bacterial insults.
Bacteria of the genus Proteus they can be transmitted through contaminated catheters, or through accidental parenteral inoculation. Although the precise mode of transmission has not yet been identified with certainty, the possibility of direct transmission is ruled out.
Cystitis, pyelonephritis and urolithiasis (stone formation in the bladder or kidneys) are the most common infections mediated by Proteus. However, following an insult from Proteus, some particularly sensitive patients may also develop bacteremia and septicemia.
The most common symptoms associated with Proteus I'm:
- alkalization of urine
- stone formation
- persistence of the infection
- renal failure (advanced stage)
The involvement of other organs is less frequent, although possible: in such circumstances, complications can also be documented
- abdominal abscesses
- cholangitis
- surgical wound infections
- purulent meningitis: diagnosed only in the newborn
- pneumonia
- septicemia (in case of severity)
- sinusitis
The close relationship between the onset of infections from Proteus and the presence of pressure sores and diabetic ulcers: the pathogens, which have entered the organism through these lesions, can also infect the bone.
Incidence
We analyzed that such bacteria Proteus they are often involved in urinary tract infections and nocosomal diseases (contracted in health-hospital structures). In Europe and America, it is estimated that 4-6% of Proteus is acquired in the community and an estimated percentage between 3 and 6% is nocosomal in nature.
The rate of infection is higher among the elderly, especially if catheterized or on antibiotic therapy for long periods; even patients with structural abnormalities of the urinary tract seem to be more at risk of this type of infection. It also appears that Proteus are more frequent in uncircumcised patients.
Proteus mirabilis is the species most involved in diseases affecting the urinary system: it is estimated that 90% of Proteus is due precisely to this species.
Proteus infections: therapy
Before proceeding with the therapy, the diagnostic assessment is essential, which fortunately is rather simple. Most of the strains of Proteus it is lactose-negative and, on agar medium, it shows the typical phenomenon of swarming. The swarm describes a particular phenomenon in which the colonies of Proteus - grown on agar medium - they do not remain confined, but form a peculiar growth film.
Most infections caused by Proteus it is sensitive to the action of cephalosporins, imipenem and aminoglycosides: this means that these drugs are the most suitable for the treatment of the infections they carry. Proteus vulgaris and how P. penneri they cannot be removed with these antibiotics, since they have developed resistance, especially to cefoxitin, cefepime, aztreonam, piperacillin, amoxicillin, ampicillin, cefoperazone, cefuroxime, and cefazolin.
Proteus mirabilis, unlike the latter and similarly to E. coli, it is rather simple to eradicate, since it is also sensitive to trimethoprim-sulfamethoxazole, amoxicillin, ampicillin and piperacillin. This bacterium is resistant to nitrofurantoin.
In case of respiratory tissue involvement, it is recommended to follow an antibiotic therapy with a higher posology than for mild infections from Proteus. For example, ciprofloxacin should be taken at a dose of 1 gram per day for mild infections from Proteus; the dosage should be doubled when the bacteria Proteus they also spread to the lungs.
