[Changes of pathogenic bacteria in pediatric patients of septicemia and drug resistance there of in Zhejiang Children's Hospital 1991 approximately 2000].

OBJECTIVE

To investigate the changes of pathogenic bacteria detected from the blood culture of pediatric patients with septicemia in the past 10 years, and to observe the drug resistance thereof in the past two years.

METHODS

The blood samples of 4 425 pediatric patients aged 0 approximately 14 with the diagnosis of septicemia 1991 approximately 2000 in Zhejiang Children's Hospital were cultured in broth (1991 approximately 1996) or VITA AER blood culture apparatus (1997 approximately 2000). Analytic Product Inc. (API ) system and KB paper strip method and VITEK automicroscan were used to identify the species and conduct drug resistance test. The results were interpreted according to the guideline of National Committee for Clinical Laboratory Standards.

RESULTS

In the past 10 years, Gram-positive bacteria remained the more frequent pathogens than Gram-negative bacteria in pediatric patients with septicemia. The proportion of coagulase-negative staphylococcus (CNS) had been increasing and reached 69% in 2000. The proportions of Staphylococcus aureus and Escherichia coli decreased from 35.4% and 18.2% in 1991 to 5.3% and 1.5% in 2000. In the past two years, the drug resistance rate of staphylococci against penicillin and erythromycin were more than 90% and 70% respectively. The oxacillin resistance rate of CNS was 60.3%, significantly higher than that of Staphylococcus aureus (10.3%). No strain of Staphylococcus and Enterococcus resistant to vancomycin was found. Escherichia coli and Psudomonas aeruginosa and other species of Enterobacteriae were sensitive to imipenem/cilastin sodium, whereas the resistance rate of them to ampicillin and first generation cephalosporins was more than 50%.

CONCLUSION

(1) Gram-positive bacteria are the predominant pathogens of pediatric patients with septicemia, with the species of Staphylococcus ranking first among which CNS is the main pathogen for infants and Staphylococcus aureus is the main pathogen for school children. (2) Escherichia coli is the most frequently found pathogenic Gram-negative bacterium in infants with septicemia whereas Salmonella in school children. (3) Drug resistance of isolated pathogenic bacteria in department of pediatrics is a serious problem. Monitoring the change of pathogen and the trends of antimicrobial resistance is very important in guiding therapy.