Study of Ampicillin Resistant Gene in Haemophilus Influenzae and in Children

Objective To study the situation of ampicillin resistance of haemophilus influenzae(HI) and to explore the resistant manchnism of HI by polymerase chain reaction.Methods Fifty-five strains of HI isolated from sputum specimens and throat swabs of children were collected to detect beta-lactamase.TEM-1 and ROB-1 beta-lactamase genes were detected by polymerase chain reaction(PCR) and nucleotide sequencing.ResultsBeta-lactamase was produced in 17 strains out of 55 strain of HI.Moreover it has ampicillin resistant.The rate of ampicillin resistance was 30.9% in HI.No beta-lactamase-negative ampicillin resistant HI was identified.100% of the beta-lactamase-positive strains gave a positive result with specific primers for the TEM-1 gene.None strain was detected for the ROB-1 gene with in 32 strains cilstrains in beta-lactamase-positive strains and 15 strains in bata-lactmase-negarive strains.ConclusionHI isolated from children with lower respiratory tract infection would be a major pathogen,and ampicillin resistant in HI was rather high.The resistance mechanism of ampicillin resistant HI was caused by beta-lactamase,mainly plasmid mediated TEM-1 type enzyme.