Antimicrobial Resistance and Molecular Epidemiology of Staphylococcus aureus Causing Bloodstream Infections at Ruijin Hospital in Shanghai from 2013 to 2018

Abstract

Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) is an important issue associated with significant morbidity and mortality and well known as a predominant pathogen causing bloodstream infection (BSis) globally. to estimate the antibiotic resistance and molecular characteristics of S. aureus causing BSIs in Shanghai, 120 S. aureus isolates (20 isolates each year) from the patients with S. aureus BSIs from 2013 to 2018 were randomly selected and enrolled in this study. Fifty-three (44.2%) MRSA isolates were determined, and no isolate was found resistant to vancomycin, daptomycin, synercid, linezolid and ceftaroline. The toxin genes tst, sec, seg and sei were found more frequently among MRSA isolates compared with MSSA isolates (all P < 0.0001). Twentynine sequence types (STs) were identified, and ST5 (23.3%) was the most common ST, followed by ST398 (11.7%) and ST764 (10.0%). SCCmec II (73.6%) was the most frequent SCCmec type among MRSA isolates. The dominant clonal complexes (CCs) were CC5 (ST5, ST764, ST965 and ST3066; 36.7%) and the livestock-associated clone CC398 (ST398, 11.7%). MRSA-CC5 was the predominant CC among MRSA isolates (37/53, 69.8%), and CC5-II MRSA was found in 34 isolates accounting for 91.9% (34/37) among CC5 MRSA isolates. In addition, all 29 tst-positive MRSA isolates were CC5-MRSA as well. Our study provided the properties and genotypes of S. aureus causing BSis at Ruijin Hospital in Shanghai from 2013 to 2018, and might suggest of value clues for the further study insights into pathogenic mechanisms intrinsically referring to the development of human-adapted S. aureus clones and their diffusions. Bloodstream infections (BSIs) is a severe infection with high incidence and lethality all over the world, and it always prolonged hospital stay for a long period 1. It has been reported to be one of the seven leading causes of death in North America and Europe 2. Staphylococcus aureus is well known as one of the most important human pathogens across the world and is capable of causing a variety of infections in healthcare facilities and communities. Furthermore, S. aureus is one of the major and most fatal causes of bacteremia with an estimated mortality of 20%, and at least 50% of patients with S. aureus bacteremia (SAB) will develop complicated bacteremia 3. S. aureus is one of the most common causes of severe BSIs with high morbidity and mortality. Early mortality associated with SAB appears to have plateaued at approximately 20-30% 4 , and imposes a substantial burden on patients and healthcare systems. In the United States, the annual incidence of SAB is 4.3 to 38.2 per 100,000 person-years, and the 30-day all-cause mortality of SAB is 20% and has not changed since the 1990s 5. In Ireland,

Human Infection of Methicillin-Susceptible Staphylococcus aureus CC398: A Review

“…In France and China, respectively, the two most affected countries, MSSA CC398 is responsible for BSI, ranging from 4.1 to 13.4%, and from 5.4 to 14.9% of all BSI [7,17,18,20,23,34,52,55,[59][60][61]. Even though MSSA CC398 infective endocarditis (IE) has been described, CC398 was equally prevalent between IE and non-IE bacteremia and represented 5.6% of MSSA endocarditis isolates [34].…”

Molecular characteristics and risk factor analysis of Staphylococcus aureus colonization put insight into CC1 colonization in three nursing homes in Shanghai

“…Antimicrobial susceptibility testing was performed on all confirmed isolates using the Kirby-Bauer disk-diffusion method [ 25 ] following the Clinical and Laboratory Standard Institute (CLSI) standards issued in 2019 [ 26 ]. In addition, referring to relevant research [ 20 , 27 , 28 ], the isolates were tested for susceptibility to the following antibiotics: penicillin (10 units), cefoxitin (30 μg), gentamicin (10 μg), kanamycin (30 μg), tobramycin (10 μg), erythromycin (15 μg), tetracycline (30 μg), teicoplanin (30 μg), minocycline (30 μg), ciprofloxacin (5 μg), clindamycin (2 μg), sulfamethoxazole-trimethoprim (25 μg), chloramphenicol (30 μg), rifampicin (5 μg), quinupristin-dalfopristin (15 μg), linezolid (30 μg), fusidic acid (10 μg), fosfomycin (200μg), and mupirocin (200 μg). The minimum inhibitory concentration (MIC) of vancomycin was determined using the agar dilution method [ 25 ].…”

Disease Severity Is an Independent Risk Factor of Mortality and Outcomes in Critically Ill Patients With Carbapenem-resistant Klebsiella Pneumoniae Bloodstream Infections: a 5-year Retrospective Analysis

“…All blood culture isolates were processed in the hospital's clinical microbiology laboratory. Bacterial species identi cations were con rmed using matrix-assisted laser desorption/ionization time-of-ight mass spectrometry (bioMérieux, Marcy-l'Etoile, France) and susceptibility testing was performed (VITEK 2, bioMérieux) (12). Minimum inhibitory concentrations (MICs) were classi ed according to breakpoints established by the Clinical and Laboratory Standards Institute (CLSI; Annapolis Junction, MD, USA).…”