Differences in distribution and drug sensitivity of pathogens in lower respiratory tract infections between general...

Lower respiratory tract infections (LRTIs) are common among patients in hospitals worldwide, especially in patients over the age of 60. This study investigates the differences in distribution and drug sensitivity of pathogens in LRTIs.

The clinical and laboratory data of 4,762 LRTI patients in the general ward and respiratory intensive care unit (RICU) of Xiangya Hospital (Changsha) were retrospectively analyzed.

The infection rate of Gram-negative bacteria was significantly higher than that of Gram-positive bacteria in both the general ward and RICU (P<0.05). The incidence of Gram-negative bacteria infection was significantly higher in the RICU than in the general ward (P<0.05), whereas the incidence of Gram-positive bacteria infection is less in the RICU than in the general ward (P<0.05). In the general ward, the incidence of Gram-negative bacteria infection significantly increased (P<0.05) over time, whereas the incidence of Gram-positive bacteria infection significantly decreased from 1996 to 2011 (P<0.05). In the RICU, the incidence of Gram-positive bacteria infection decreased, while Gram-negative bacteria infections increased without statistical significance (P>0.05). Staphylococcus pneumoniae and Staphylococcus aureus were found to be the predominant Gram-positive strains in the general ward (34.70-41.18%) and RICU (41.66-54.87%), respectively (P>0.05). Pseudomonas aeruginosa and Acinetobacter baumannii were the predominant gram negative strains in the general ward (19.17-21.09%) and RICU (29.60-33.88%), respectively (P>0.05). Streptococcus pneumoniae is sensitive to most antibiotics with a sensitivity of more than 70%. Staphylococcus aureus is highly sensitive to vancomycin (100%), linezolid (100%), chloramphenicol (74.36-82.19%), doxycycline (69.57-77.33%), and sulfamethoprim (67.83-72.46%); however, its sensitivity to other antibiotics is low and decreased each year. Sensitivity of Pseudomonas aeruginosa to most β-lactam, aminoglycoside, and quinolone group antibiotics decreased each year.

The distribution and drug sensitivity of LRTI pathogens exhibit a high divergence between the general ward and RICU. Streptococcus pneumoniae may not be the predominant pathogen in LRTIs in some areas of China.