[Pathogen distribution and antibiotic resistance for hospital aquired pneumonia in respiratory medicine intensive care unit].

OBJECTIVE: To investigate the change of pathogen distribution and antibiotic resistance of pathogens isolated from in-patients with hospital acquired pneumonia (HAP) in the Department of Respiratory Medicine Intensive Care Unit (RICU) of Xiangya Hospital in 2005 and in 2011, and to provide reasonable anti-infectious strategy.

METHODS: The positive susceptibility test of sputum (bronchial secretions) culture was done in patients with HAP in RICU of Xiangya Hospital in 2005 and in 2011, and the distribution feature and antibiotic resistance were compared.

RESULTS: 1) In the two years, the main pathogen in HAP patients was Gram negative bacteria (infection rate was 68.07% and 65.21% in 2005 and in2011 respectively). The primary pathogenic bacteria were changed, and Acinetobacter baumanii became the most common Gram negative bacterium which replaced Pseudomonas aeruginosa, with infection rate 6.81% in 2005 to 40.87% in 2011. The infection rate of Pseudomonas aeruginosa reduced from 20.42% in 2005 to 15.60% in 2011. Haemophilus influenzae was rare. Staphylococcus aureus became the primary Gram positive bacteria, and its infection rate increased from 1.57% in 2005 to 4.83% in 2011, all of which were methicillin-resistant Staphylococcus aureus (MRSA). Saccharomyces albicans' positive culture rate increased significantly. 2) Compared with in 2005, the antibiotic resistance of pathogen isolated from the HAP pationts changed a lot in 2011: increased antibiotic resistance rate and decreased sensitivity to many antibiotics. Pseudomonas aeruginosa was only relatively susceptible to meropenem, cefoperazone sulbactam, ceftazidime, cefpodoxime, and andamicaxin in 2011. The resistance rate of Pseudomonas aeruginosa to levofloxacin, cyclopropane, amicacin, gentamicin, meropenem, cematrixone, and piperacilintazobactam increased obviously (P<0.05). Compared with 2005, Acinetobacter baumanii was totally susceptible to polymyxin and relatively susceptible to sulbactam, but it was almost completely resistant to Aminoglycoside antibiotics in 2011, with significant difference (P<0.01).

CONCLUSION: The main pathogen of HAP patients in RICU was Gram negative bacteria, with increased infection rate of Staphylococcus aureus and fungus. There is change pathogen distribution and antibiotic resistance, and the clinical initial experimental antibiotic therapy may be influenced. It is important to use antibiotics more rationally to delay the antibiotic resistance.