Objective To study the molecular mechanisms of ampicillin-resistant haemophilus influenzae （Hi） in Nanjing. Methods One hundred and fifty - eight strains of Hi isolated from children wcrc collected to detect bata-lactamase. TEM and ROB bata-lactamase genes were detected by polymerase chain reaction （PCR）, and cloned into T vector for sequencing. Results The rate of ampicillin resistance was 41.77% in Hi isolated from children in Nanjing, 40.51% was found to be bata - lactamase production. Eighty - nine strain were TEM positives, 1 strain was ROB positive, 63 strains bata - lactamase positive ampicillin-resistant Hi were identified. The resistance mechanism of ampicillin resistant Hi was production of bata - lactamase, mainly TEM - type enzyme. Two bata-lactamase negative ampicillin - resistant Hi were identified, predicts the other mechanisms of ampicillin-resistant Hi was occuered yet. One strain of non - TEM - type, and non - ROB - type bata - lactamase - producing Hi was identified. Conclusions Amplcillin - resistant in Hi isolated from children in this region is challenging. TEM bata - lactamase is the principal mechanism of ampicillin - resistant of Hi.
Journal of Applied Clinical Pediatrics