Distribution and drug resistance of pathogenic bacteria in ventilator-associated pneumonia at a local hospital of North-eastern China.

PURPOSE

To study the distribution of pathogenic bacteria in ventilator-associated pneumonia (VAP), and epidemiological characteristics of extended-spectrum β lactamase (ESBL)-producing bacteria.

PATIENTS AND METHODS

Lower respiratory tract secretions from 156 patients with mechanical ventilation were collected using a protective specimen brush (PSB), with quantitative bacterial culture carried out and antibiotic sensitivity measured. ESBLs produced by Gram-negative bacilli were detected using the double disk diffusion method and monitored by plasmid profiles.

RESULTS

Gram-negative bacilli accounted for 78.9% of VAP pathogens, with (25%), (19.7%), and (14.5%) as the most common strains. There were 12 Gram-positive strains detected (15.8%); mostly methicillin-resistant. and methicillin-resistant coagulase-negative . There were also four strains of detected (5.26%). Most Gram-negative bacilli are sensitive to imipenem, but is serious resistant. ESBLs were detected in nine strains of Gram-negative bacilli; mainly produced by and , to different degrees of multidrug resistance. Five strains of -producing ESBLs were from the same clonal origin, as confirmed by plasmid restriction endonuclease analysis.

CONCLUSION

VAP was mainly caused by Gram-negative bacteria, with high antibiotic resistance rates. Plasmids played an important role in the spread of antibiotic resistance among bacteria.