ABSTRACT
Objective To investigate the drug-resistance of Staphylococcus aureus induced by erythromycin in vitro and its changes in growth and susceptibility of antibiotics.Methods Erythromycin in vitro induction was conducted with the S.au-reus reference strain ATCC25923 on the serial of erythromycin agar plates.The growth of S.aureus,and the susceptibility a-gainst other antibiotics was compared after induced to the parent strain.Results Resistance to erythromycin was successful-ly,and themaximum MIC was over 256 mg/L.The Erythromycin-resistant S.aureus grew much slower than the susceptible parent,and the strains didn’t have cross-resistance to other antibiotics.Conclusion S.aureus could be induced resistance in vitro by erythromycin,and this resistance inherited stably.Some phenotype and biochemical characteristic features of the strain were changed after induced.
ABSTRACT
Objective To assess the relationship between the serum IgG antibody titer of pregnant women and the hemolytic dis‐ease of newborn(HDN) .Methods Using microcolumn gel coombs card assay method to determine titer of 255 cases of couples an‐tenatal serum IgG antibody and ABO blood group .Results with 195 cases of ABO‐incompatible couples ,the positive rate of abnor‐mal serum IgG antibody(≥64)was 93 .8% .The titer of anti‐A/B IgG :in 12(6 .2% ) cases was <64;in 12(6 .2% )cases was 64;in 60(30 .8% )cases was 128 ;in 39(20% )cases was 256 ;in 45(23 .0% )cases was 512 ;in 27(13 .8% ) cases was 1 024 .There were no statistical differences between IgG anti‐A(B) titers distribution between A/O blood group matching and B/O blood group matching (χ2 =4 .361 ,P=0 .499) ,IgG anti‐A( B) titers was higher in AB/O blood group matching .Conclusion we can take early and effec‐tive prevention ,treatment ,reducing the incidence of HDN by the determination of prenatal serum IgG antibody titers in ABO‐in‐compatible couples ,which is important for the population of eugenics .