›› 2010, Vol. 30 ›› Issue (5): 562-.

• Original article (Clinical research) • Previous Articles     Next Articles

Formation and characteristics of Acinetobacter baumannii bacterial biofilm on inner surfaces of endotracheal tubes of burn patients

XIANG Jun, SUN Zhen, XIA Jun-xing, SONG Fei, |HUAN Jing-ning   

  1. Department of Burns &|Plastic Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China
  • Online:2010-05-25 Published:2010-05-28

Abstract:

Objective To observe the formation and characteristics of Acinetobacter baumannii bacterial biofilm (BF) on inner surfaces of endotracheal tubes of burn patients. Methods Samples of clinical strains were obtained from inner surfaces of endotracheal tubes of burn patients, and 9 drug resistant Acinetobacter baumannii strains were isolated and identified by Vitek2 Automated Identification System. Clinical strains were cultured in vitro for 12, 24, 48 and 72 h, respectively, and modified microtiter-plate method was employed for semi-quantification test of BF formation. The thickness of mature BF of samples was determined by confocal laser scanning microscopy (CLSM) with FITCConA/PI immunofluorescence double staining. Acinetobacter baumannii standard stains (ATCC19606) were served as controls. Meanwhile, samples of inner surfaces of endotracheal tubes were collected at tube withdrawal, and were also observed by scanning electron microscopy. Results Compared with standard strains, the adherence capabilities of clinical strains isolated from the tubes were much more enhanced (P<0.05), and the peak time of adherence for all strains was at 24-48 h post culture. CLSM revealed that mature BF of clinical strains was formed after culture for 48 h, and was much thicker than that of the standard strains (P<0.05). SEM revealed that mature BF assembled in mass, and the bacteria were embedded in the matrix. Conclusion Acinetobacter baumannii strains can form BF on the inner surfaces of endotracheal tubes of burn patients with favorable characteristics, which is a major cause for endotracheal tube associated infection in burn patients.

Key words: burn infection, Acinetobacter baumannii, bacterial biofilm, endotracheal tube