OBJECTIVETo investigate the variance and drug resistance of pathogenic bacteria isolated from children with infectious diseases seen between 2001 and 2006 in Chengdu area.

METHODSA total of 2888 pathogenic bacterial strains isolated from children in Chengdu Children's Hospital from 2001 to 2006 were analyzed. Tests were performed according to the guidelines of National Committee for Clinical Laboratory Standards (NCCLS) of the United States.

RESULT(1) Of the 2888 strains, 1845 (63.9%) were Gram negative bacteria. The main pathogenic bacteria included Escherichia coli (Ec, 718 strain, 24.9%), Hemophilus (H, 476 strain, 16.5%), Streptococcus pneumoniae (Sp, 412 strain, 14.3%), Klebsiella pneumoniae (Kp, 369 strain, 12.8%), Staphylococcus aureus (Sa, 353 strain, 12.2%), Staphylococcus epidermidis (Se, 278 strain, 9.6%), Pseudomonas aeruginosa (Pa, 146 strain, 5.1%) and other non-zymocyte (Onz, 136 strain, 4.7%). (2) The common pathogens found in blood specimen were 158 strain, which included Se (78 strain, 49.4%), Ec (23 strain, 14.6%), Kp (17 strain, 10.8%), Sa (14 strain, 8.9%), Onz (14 strain, 8.9%), Sp (7 strain, 4.4%) and Pa (5 strain, 3.2%). (3) The number of common pathogens isolated from patients with lower respiratory tract infection was 2018, including Ec (441 strains, 21.9%), H (430 strains, 21.3%), Sp (368 strains, 18.2%), Kp (253 strains, 12.5%), Sa (207 strains, 10.3%), Se (149 strains, 7.3%), Pa (97 strains, 4.8%) and Onz (73 strains, 3.6%). (4) There were 120 strains of common pathogens isolated from urine specimens, including Ec (78 strains, 65%), Kp (25 strains, 20.8%), Onz (7 strains, 5.8%), Pa (5 strains, 4.2%) and Se (5 strains, 4.2%). (5) There were 497 strains of common pathogens found in pus specimens, including Ec 167 strains, (33.6%), Sa (126 strains, 25.4%), Se (46 strains, 9.3%), H (44 strains, 8.9%), Onz (37 stains, 7.4%), Kp (31 strains, 6.2%), Sp (26 strains, 5.2%) and Pa (20 strain, 4.0%). The trend of drug resistance of pathogenic bacteria to antibiotics deteriorated. The proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 6.7% and the methicillin-resistant coagulase-negative Staphylococci (MRCNS) rate was 20% in 2001 - 2003. The total proportion of extended-spectrum beta-lactamase stains (ESBL(S)) in Ec and Kp was 21.8%, and the rate of beta-lactamase production stains of Hemophilus influenzae (Hi) was 19.4% in 2001 - 2003.The proportion of MRSA was 17.2% and the MRCNS rate was 70.2%, the total proportion of ESBL(S) in Ec and Kp was 43.8%, and the rate of beta-lactamase producing stains of Hi was 39.7% in 2004 - 2006.

CONCLUSIONThe distribution of common pathogenic bacteria seen in Chengdu Children's Hospital has changed and the trend of drug resistance of pathogenic bacteria to antibiotics deteriorated in recent three years. Regionally monitoring the changes in pathogenic bacteria and the trend of drug resistance to antibiotics is paramount in guiding the pediatric clinical treatment.