PROTEUS MIRABILIS: CHARACTERISTICS, MORPHOLOGY, CONTAGION, SYMPTOMS - BIOLOGY - 2025

Proteus mirabilis is a Gram negative bacterium of the Enterobacterial order that can live both in the presence and in the absence of oxygen (facultative anaerobic). It is common in soil, water, in materials with fecal contamination, and in the digestive tract of vertebrate animals, including humans.

This bacterium is generally rod-shaped, but it is a dimorphic organism with swarm mobility. Additionally, they react negatively towards indole and lactose. On the other hand, it is an oxidase negative bacterium, which implies that it is incapable of using oxygen in the electron transfer chain.

Proteus mirabilis, exposed to penicillin. Taken and edited from Geoman3

This was mainly due to the formation of a biofilm of this bacterium in surgical equipment, which is highly resistant to antimicrobial agents and substances.

Bacterial endocarditis

The contagion of this heart disease caused by the Proteus mirabilis bacteria is quite rare and unusual. However, there are some cases reported in Mexico, Cuba and the US In these cases it is presumed that the contagion could have been via the kidney and then spread through the blood.

Symptoms

Symptoms of urinary infections

There are several urinary infections caused by the Proteus mirabilis bacteria. The names and symptoms are as follows:

Cystitis

With cystitis there is difficulty and pain when urinating; even so, there is an increase in the frequency and desire to urinate, the urine is scanty and sometimes dark. There is pain in the upper part of the pubic area and even in the back. In complicated cases, fever, bacteremia and sepsis may occur.

Urethritis

This infection manifests as an inflammation of the urethra. There are problems and pain when urinating, with urine mixed with pus (pyuria) and increased desire and frequency to urinate.

Prostatitis

This infection attacks men. Like cystitis, there is difficulty and pain when urinating, increased frequency and the urge to urinate, the urine is scanty and dark, and sometimes symptoms such as fever and chills may occur.

This pathology is common in patients of middle age (over 40 years) to more advanced. During the medical examination, the urologist may detect additional symptoms such as a swollen prostate and palpitations in the prostate.

Pyelonephritis

Pyelonephritis caused by bacteria (Proteus mirabilis) is characterized by symptoms similar to cystitis and urethritis.

However, symptoms such as flank pain (areas where the kidneys and renal capsules are), fever, nausea, vomiting, blood in the urine, and enlargement of the kidneys to touch or palpation are added to this pathology.

Symptoms of community pneumonia

This pulmonary infection is characterized by the fact that patients present pain in the chest that intensifies with breathing, coughing, mucous and purulent elimination during coughing and shortness of breath. Fever, sweating, and chills also occur.

Symptoms of postoperative endophthalmitis

The symptoms of this infection are eye pain, intense inflammation of the eyeball, decreased vision, red eye (ciliary and conjunctival hyperemia), there are also presence of leukocytes and fibrins in the anterior ocular chamber and ocular secretions.

Symptoms of bacterial endocardirtis

Endocarditis caused by the bacterium Proteus mirabilis, like that of other bacteria, is characterized in its acute form by high fever, tachycardia, shortness of breath, as well as the presence of damage to the heart valve.

The subacute infection, in turn, manifests with symptoms such as fatigue, breakdown or low fever, unremarkable tachycardia, decreased body weight, and low red blood cell count.

Treatments

The main treatment for infections of bacterial origin caused by Proteus mirabilis is the administration of antibiotics.

For urinary conditions

When they are mild, oral treatment of trimethoprim / sulfamethoxazole is recommended for at least 3 days. But for acute conditions, experts may prescribe fluoroquinolones for 7 to 14 days. Another suggested alternative treatment is gentamicin, followed by trimethoprim / sulfamethoxazole, also for 7 to 14 days.

Regarding chronic or serious infections, especially if they were acquired in hospital, the intravenous administration of various antibiotics such as gentamicin, fluoroquinolone, gentamicin / ampicillin is recommended until the fever ceases and it is possible to switch to oral treatment.

Oral treatment, for its part, could be trimethoprim / sulfamethoxazole for 14 additional days to the previous treatment.

Community pneumonia

It is recommended to avoid smoking, it is also necessary to consume a lot of fluids; some doctors prescribe acetaminophen to decrease fever. Antibacterial treatment is varied, however the use of ceftriazone, orally, once a day for 3 to 5 days stands out; If the fever does not stop, increase the treatment up to 7 to 10 days.

Postoperative endophthalmitis

For the treatment of this bacterial infection, the community of ophthalmologists is divided; Some recommend, depending on the severity of the pathology, drugs ranging from linezolid every 12 hours by mouth, to intraocular injections of vancomycin + ceftazidime.

Bacterial endocardirtis

When it comes to this bacterial pathology, surgical intervention is often recommended. For the antibacterial treatment against Proteus mirabilis, high doses of antibiotics are used intravenously, for a minimum time of two weeks (usually 4 to 6 weeks) with gentamicin every 8 hours (there are other antibiotic treatments).

References

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