Epidemiology of nosocomial infections with methicillin-resistant Staphylococcus in the Republic of Moldova

The novelty of the subject. Healthcare-associated infections (HAIs) have become one of the major public health problems from the clinical, epidemiological and socio-economic perspectives. They represent a special chapter of pathology highlighted in the context of modern medical advances, determined by the diversity of diagnostic and therapeutic maneuvers, also due to the irrational use of antibiotics, especially the broad-spectrum ones, which leads to the selection of resistant bacteria [1, 2, 3, 4, 5]. Healthcare-associated infections caused by antibiotic-resistant microorganisms are one of the most important challenges for modern medicine today. A large part of Staphylococcus aureus infections are produced by a microbial pathogen resistant to a wide range of antibiotics used in the hospital environment, namely, methicillin-resistant Staphylococcus aureus (MRSA) [6]. From the first cases of MRSA to date, the problem has increased dramatically, the incidence of MRSA infections reaching endemic proportions in some hospitals. In Europe, a north-south gradient is observed, MRSA strains being rare in Scandinavian hospitals ( 40%) [7, 8, 9]. Although in recent years the percentage of methicillin-resistant Staphylococcus aureus strains has decreased in the European Union / European Economic Area (EU / EEA), from 19.6% in 2014 to 16.9% in 2017, however, MRSA remains an important challenge at the European level, with high MRSA levels in several countries and an increased overall antimicrobial resistance [10, 11, 12, 13]. In 2017, the World Health Organization (WHO) established the most important categories of multidrug-resistant germs, which required the introduction of new therapeutic options with 3 priority levels: critical, high and medium; methicillin-resistant Staphylococcus aureus strains belonging to the high level [14, 15]. Shortly after the emergence of MRSA, it was realized that the problem of methicillin resistance involves not only coagulase-positive staphylococci (CPS), but also coagulase-negative staphylococci (CNS). Although in the beginning, these species of microorganisms were given little importance, being considered part of the normal flora of the skin and nasal mucosa, today, due to their resistance to antibacterial preparations, they have become a source of concern for the medical system. They are especially associated with the use of foreign bodies, implants, etc., which are indispensable in modern medicine [16, 17]. Increased rates of antibiotic resistance have been shown to be even a greater problem for CNS than for Staphylococcus aureus, limiting the treatment options [18, 19]. Methicillin resistance has been shown to have a negative impact on clinical and economic outcomes, especially in terms of increased morbidity and mortality and long-term hospitalization, as well as the need for additional interventions to mitigate the clinical impact [20, 21, 22, 23, 24, 25]. The ranking of staphylococci first in the etiology of bacterial infections, the annual increase in the number of methicillin-resistant staphylococcal strains and the emergence of strains resistant to spare antistaphylococcal antibiotics, place this medical condition among emerging infectious diseases [26, 27, 28, 29]. In the Republic of Moldova, studies on the incidence of infections caused by methicillin-resistant Staphylococcus (MRS) are fragmentary [28, 29, 30]. Knowledge of local epidemiology of methicillin-resistant Staphylococcus infections will contribute to raising the awareness of the problem and implementation of rational measures for surveillance and control of the given medical condition. [...