When it comes to dangerous bacteria, most people immediately think of E. coli, Staphylococcus aureus, or Acinetobacter baumannii . However, there are lesser-known microorganisms that can cause just as much harm to the human body. One such microorganism is Proteus vulgaris . Although less well-known, this bacterium belongs to the genus Proteus and can cause severe infections, especially in those with weakened immune systems.

Proteus vulgaris - what is it?

A Gram-negative, facultatively anaerobic bacterium belonging to the Enterobacteriaceae family. It typically inhabits soil, water, and the gastrointestinal tract of humans and animals. In healthy individuals, it usually causes no symptoms, but in hospital settings or in immunocompromised individuals, it can become a serious pathogen.

One of the characteristic features of this bacterium is its ability to actively move thanks to flagella. It also produces the enzyme urease, which allows it to survive in the urinary tract, causing infections, especially in the presence of catheters.

How is Proteus vulgaris transmitted and how to protect yourself from it?

The primary route of infection is contact. This means the bacteria can be transmitted through contaminated hands of medical personnel, instruments, or surfaces. It poses a particular danger in hospitals, where patients with open wounds, catheters, or post-surgical patients are the most vulnerable.

To avoid infection, it is important to practice good hygiene, regularly wash your hands, properly care for catheters, and avoid using them for long periods of time unless necessary.

Diseases caused by Proteus vulgaris

The bacteria can cause:

• urinary tract infections (especially in the presence of catheters);

• wound infections, including postoperative;

• sepsis - the spread of infection through the blood throughout the body;

• pneumonia - less common, but infection of the lungs is possible;

• infections of joints and bones (osteomyelitis, septic arthritis).

Symptoms vary depending on the location of the infection, but most commonly include:

• fever;

• pain when urinating (in case of urinary tract damage);

• redness, pus and pain in the wound area;

• general weakness, intoxication of the body.

The challenge of treatment: the problem of resistance

Over the past decades, Proteus vulgaris has acquired multidrug resistance (MDR). It is capable of producing extended-spectrum beta-lactamases (ESBLs), which neutralize many antibiotics, including penicillins, cephalosporins, and carbapenems.

Because of this, treatment often requires the use of powerful reserve antibiotics, such as colistin, which is itself toxic. Even then, effectiveness is not always guaranteed.

Moreover, prolonged antibiotic use further contributes to the spread of resistant strains. This necessitates new treatment approaches, one of which is phage therapy.

Phages vs. Proteus vulgaris: How Good Viruses Work

Bacteriophages are viruses that selectively infect bacteria without harming human cells. They operate like a sniper: each type of phage targets a specific species or even strain of bacteria. This selectivity makes them extremely promising in the fight against antibiotic-resistant infections.

When a bacteriophage finds "its" bacterium—in this case, Proteus vulgaris—it attaches to its surface, injects its genetic material, and begins replicating inside the cell. The pathogen soon ruptures, releasing new phages, which continue to destroy other bacterial cells. Thus, the phages replicate inside the bacteria and destroy the pathogen without harming beneficial microflora.

Research in the field of phage therapy against Proteus vulgaris

Although phage therapy against Proteus vulgaris has not yet been widely used, scientists are actively exploring its potential.

A team of researchers from Anna University in Chennai, India, has isolated a bacteriophage from wastewater that can effectively kill Proteus vulgaris, even multidrug-resistant bacteria.

A phage cocktail was tested against a range of Gram-negative bacteria, including Proteus vulgaris, at the Warsaw University of Medical Sciences . According to the study, the use of phages reduced the bacterial load in a mouse model of infected wounds. In some cases, the effect was superior to antibiotics.

For several decades, the Eliava Phage Therapy Center in Tbilisi, Georgia, has been using bacteriophages to treat infections caused by various strains of Proteus, including Proteus vulgaris. Phage cocktails have been administered to patients with chronic urinary tract infections, and the results have shown significant improvement, even when antibiotics have failed.

Although phage therapy against Proteus vulgaris is still in the early stages of research, its results provide grounds for optimism. Thanks to its selectivity, lack of toxicity, the ability to combine phages with antibiotics, and zero impact on beneficial bacteria, this approach could become the basis of medicine of the future.