Staphylococcus aureus (S. aureus) is one of the most serious and well-known human pathogens. While some strains can exist as commensals, others are the primary cause of hospital and community-associated infections [1]. It has become one of the main agents associated with pathogenic antibacterial resistance and the production of multiple virulent factors. The indiscriminate and increasing usage of antimicrobials has principally accelerated the expansion of resistance [2]. Methicillin-resistant S. aureus (MRSA) has traditionally been considered the main agent of community- and hospital-acquired pathogens. The bulk of the current information on MRSA population structure comes from Europe, the USA, Asia, and Australia [3]. Although S. aureus accounts for 0.5% to 6% of urinary tract infections (UTIs), these bacteria can cause serious infections including skin and soft tissue infections (SSTIs), as well as life-threatening systemic complications such as sepsis and bacteremia [4]. Based on the survey, 5 community-associated (CA)-MRSA clones causing outbreaks have been identified [5].

The results of studies have shown that MRSA shows high resistance to most antibiotics, including fluoroquinolones, peptides, aminoglycoside, macrolide, and tetracycline. Therefore, information on new antibacterial agents is essential to treat infectious diseases caused by multidrug resistance (MDR) Gram-positive pathogens [6]. In fact, the emergence of antibiotic resistance among MRSA strains and the unavailability of treatment options for the management of MRSA infections continue to be a major challenge for healthcare [7].

Currently, vancomycin is the preferred treatment for severe infections caused by MRSA, but since 1997, vancomycin-intermediate S. aureus (VISA) strains have emerged, causing significant concern worldwide [8]. Tigecycline (TG) is one of the first glycylcycline antimicrobial agents derived from minocycline, and it exhibits high activity against many multidrug-resistant bacteria, including MRSA. However, reports of studies related to the resistance of Gram-positive bacteria, including S. aureus, to TG have been variable [9].

The U.S. Food and Drug Administration (FDA) has approved TG [1] to treat complicated intra-abdominal infections, complicated skin and skin-structure infections, and community-acquired bacterial pneumonia. It represents a useful therapeutic option for treating complicated infections caused by multidrug-resistant organisms with limited treatment options [10]. TG prevents tetracycline resistance mechanisms such as the ribosomal protective cover provided by tet M because it binds to the bacterial ribosome with a more diverse orientation than classical tetracyclines [11].

In this study, the TG resistance evaluation and monitoring test (T.E.S.T.) is a global surveillance study designed to monitor bacterial resistance to TG in MRSA. We report the activity of TG in MRSA from around the world by 2022.