Epidemiology and microbiology of Gram-positive bloodstream infections in a tertiary-care hospital in Beijing, China: a 6-year retrospective study

Qiang Zhu, Yan Yue, Lichen Zhu, Jiewei Cui, Minghui Zhu, Liangan Chen, Zhen Yang, Zhixin Liang

Gram-positive bacterial bloodstream infections (BSIs) are serious diseases associated with high morbidity and mortality. The following study examines the incidence, clinical characteristics and microbiological features, drug resistance situations and mortality associated with Gram-positive BSIs at a large Chinese tertiary-care hospital in Beijing, China. A retrospective cohort study of patients with Gram-positive BSIs was performed between January 1, 2011, and June 31, 2017, at the Chinese People's Liberation Army General Hospital. The patients' data were collected and included in the reviewing electronic medical records. A total of 6887 episodes of Gram-positive BSIs occurred among 4275 patients over 6 years, and there were 3438 significant BSI episodes 69% of these cases were healthcare-associated, while 31% were community-associated. The overall incidence of Gram-positive BSIs fluctuated from 7.26 to 4.63 episodes per 1000 admissions over 6 years. Malignancy was the most common comorbidity and indwelling central intravenous catheter was the most common predisposing factor for BSI. Staphylococci were the major pathogen (65.5%), followed by Enterococcus spp:(17.5%), Streptococcus spp.(7.1%) and other bacterial pathogens (9.9%). The resistance rates of Staphylococci and E.faecium to penicillins were more than 90%. the vancomycin-resistant isolates were E. faecium (4.1%) and staphylococcus epidermidis (0.13%); and only E.faecalis and E.faecium showed resistance to linezolid (3.8% and 3.1%). Between 2011 and 2017, the overall mortality of Gram-positive BSIs decreased from 6.27 to 4.75% (X2 = 0.912, p = 0.892). Neverthess, the mortality in the ICU decreased from 60.46 to 47.82%, while in the general ward it increased from 39.54 to 52.18%. The morbidity and mortality of Gram-positive BSIs have showed downward trends. Vancomycin and linezolid are still consider the best treatment for patients with Gram-positive BSIs.