Introduction: Bacterial infections have a substantial impact on global health and can become serious if misdiagnosed with several diseases related to the central nervous, cardiovascular, and respiratory systems. The prognosis in patients with infectious disease strongly depends on early diagnosis and appropriate antibiotic therapy. We aimed to compare the accuracy of genus and species-level identification bacteria using biochemical testing and 16S rRNA sequence analysis. Material and methods: 50 clinical samples were isolated and identified the pathogenic bacteria by routine laboratory methods. In parallel, DNA was extracted from isolate’s colonies and amplified the 16S rRNA gene by using specific primers. The PCR products were evaluated by agarose gel electrophoresis and direct sequencing by the Sanger method. The sequence data were manipulated by Geneious Prime software. The sequence data matching the Prokaryotic 16S Ribosomal RNA database with a similarity score of ≥ 98% were selected. Results: Total of 50 clinical samples were isolated and identified the pathogenic bacteria with common biochemical test and API® Microbial Identification. The sequencing data showed that almost species identified by 16S rRNA sequencing matched the biochemical test method. There are 3 species (6%) were identified as different species with the routine methods. Conclusions: 16S rRNA gene sequencing is more sensitive, easier to manage, more accurate and especially for bacteria that are difficult to identify. 16S rRNA sequencing is considered an effective method to early identify pathogens in clinical samples, and this technique is increasingly being used in microbiology laboratories Key words: 16S rRNA gene, Sanger sequencing, bacterial identification, misdiagnosed

Group B streptococcus (GBS) infections are still the leading cause of invasive infections in neonates, specically they also seriously cause mortality and morbidity with underlying diseases in adults. Curently, there are ten GBS serotypes (Ia, Ib, and II-IX) and the resistance characteristic of GBS is important to clinical treatment. Objectives and methods: 30 clinical isolates of GBS were obtained from patients in Hue Central Hospital, Vietnam, from January 2016 until Jun 2019. Then the isolated GBS was conducted antimicrobial susceptibility test to determine the antibiotic resistance and serotypes by a multiplex PCR method. Results: GBS strains were resistant to tetracycline (100%), azithromycin (82.6%), erythromycin (80%) and clindamycin (80%). Resistance rates were lower with levofloxacin (45%), chloramphenicol (52.6%) and ceftriaxone (6.7%) whereas resistance was not observed in ampicillin, vancomycin and penicillin G. The distribution rate of serotype V (66.67%) was higher than type I (33.33%). Conclusions: Antibiotic resistance characteristics of GBS in samples are mostly familiar with other studies: β -lactams and vancomycin were the most susceptible antibiotics to GBS, the resistance rate in second line drug like clindamycin and erythromycin were high but there were large differences between studies. This study determined two GBS serotypes of Ia and V among isolated strains. Key words: Streptococcus agalactiae, GBS, antibiotic resistance, serotype.