NEW STRAIN OF KLEBSIELLA PNEUMONIAE RESISTANT TO ANTIBIOTICS IDENTIFIED IN ITALY

In hospitals worldwide, antibiotic resistance is among the most pressing challenges facing public health. In this context, a recent study conducted by a team of Italian researchers has, for the first time in Italy, identified a particularly resistant strain of Klebsiella pneumoniae, known as ST437. The strain carries a variant of the NDM enzyme (New Delhi metallo-beta-lactamase), which is capable of hydrolysing carbapenems and reducing the activity of cefiderocol. This discovery raises new concerns about the spread of bacteria resistant to antibiotics that are often considered the last line of defence against severe infections with limited treatment options.

The study, published in Frontiers in Cellular and Infection Microbiology, was made possible thanks to the collaboration between several healthcare and academic institutions, including the ‘G. Mazzini’ Hospital in Teramo, the ‘Maria SS. dello Splendore’ Hospital in Giulianova, the University of L’Aquila and the Istituto Zooprofilattico Sperimentale of Teramo (IZSAM). The research focused on a particularly complex clinical case: an 85-year-old patient hospitalised for a femur fracture who developed an infection caused by Klebsiella pneumoniae ST437, which proved resistant to numerous antibiotics, including newer drugs such as ceftazidime/avibactam and cefiderocol.

“The identification of this strain in an Italian hospital setting is a warning sign we cannot ignore – says Alessandra Cornacchia, researcher at IZSAM – It is a bacterium with an extremely high level of resistance, which severely limits the therapeutic options available to physicians.”

Through advanced genomic analysis, the research team identified the genes responsible for the resistance of the ST437 strain: blaNDM-5, blaOXA-232 and blaCTX-M-15. The presence of these genes gives the bacterium the ability to inactivate most antibiotics commonly used in hospital settings. “This type of resistance poses serious difficulties in the treatment of infections, especially in frail or immunocompromised patients – adds Cornacchia – For this reason, it is essential to implement infection-control measures and strengthen microbiological surveillance.”

Following this discovery, the hospital involved adopted preventive measures to contain the spread of the strain, including isolating the patient and reinforcing hygiene protocols. “Attention to prevention is fundamental: we must avoid the further spread of such strains, which could put other patients at risk,” the researcher points out.

The identification of Klebsiella pneumoniae ST437 in Italy is an important reminder of the need for effective strategies to monitor antimicrobial resistance. Collaboration between healthcare institutions and research centres is essential to better understand the dynamics of how these pathogens spread and to develop new strategies to counter them. “We need to continue investing in research and surveillance – concludes Sofia Chiatamone Ranieri, Director of the Clinical Pathology Unit at the ASL of Teramo – because the fight against antibiotic resistance is a battle none of us can afford to ignore.”