OBJECTIVE:To provide reference for the application of antibiotics based on susceptibility test.METHODS:The problems appeared in the use of antibiotics based on susceptibility test in clinical pharmacy were analyzed and summarized.RESULTS & CONCLUSION:The antibiotics should be used rationally based on susceptibility test so as to improve the rational use of antibiotics.

Objective:To carry out invasive prenatal diagnosis for a fetus with ultrasound-indicated agenesis of corpus callosum and explore its genetic etiology.Methods:A pregnant woman presented at the Affiliated Hospital of Putian College on December 16, 2022 was selected as the study subject. Amniotic fluid and peripheral blood samples from the fetus and the couple were collected. Conventional G-banded chromosomal karyotyping was carried out, and whole-genome copy number variation analysis was performed using single nucleotide polymorphism microarray (SNP-array).Results:The karyotypes of the fetus and the couple were normal by the G-banding analysis. SNP-array analysis of the amniotic fluid sample revealed a 4.5 Mb microdeletion in the 18q21.2q21.31 region of the fetus. SNP-array analysis of peripheral blood samples from the couple did not find any abnormality.Conclusion:Through G-banded chromosomal karyotyping and SNP-array analysis, a fetus with 18q21.2q21.31 microdeletion was identified, which has conformed to the diagnosis of Pitt-Hopkins syndrome. Above finding has provided a basis for genetic counseling for the couple.