Objective　 To investigate the changing spectrum and antibiotic resistance of the pathogenic bacteria isolated from general surgical infections.　Methods　 The relevant bacterial materials from 557 patients with general surgical infection from June 1993 to July 1997 were investigated.　Results　 1 045 strains in 38 species of gram-negative bacteria and 418 strains (8 species) of gram-positive bacteria were isolated with a negative over positive rate of 71.4% to 28.6%. For gram-negatives, E coli was the most common, and enterobactor cloacae ranking the third was on a dramatic increase from isolations. Staphylococcus aureus and staphylococcus epidemidis were the most common gram-positive species followed by enterococcus faecalis. Enterobactor cloacae and enterococcus faecalis are multi-antibiotic resistant bacteria. The result of drug susceptibility test showed that gram-negative bacteria were sensitive to fluoroqinolones or third-generation cephalosporins while gram-positive bacteria were sensitive to vancomycin and rifampicin.　 Conclusion　 This study showed that the rational application of antibiotics is very important to suppress the spectrum changing and antibiotic resistance of the bacteria.

Aim To clone apoptosis-related genes from human MCF-7 breast cancer cells and to analyze the character of the method used in the process. Methods A poptotic cell model of MCF-7 cells was established with the apoptotic tumor cells induced by the all-trans-retinoic acid. The apoptotic gene was cloned from the model by improved PCR-based subtractive hybridization. Results 5 clones were identified to be related to apoptosis by reverse dot blot, 4 of them were known genes, and 3 were related to apoptosis. A novel gene， named apmcf-1, coded for 47 amino acid was identified. This gene was accepted by Genbank, the accession number was AF141882. Conclusion This improved PCR-based subtractive hybridization may be an efficient way in cloning differential expression gene.