The degree of salmonellosis is associated with the genetic diversity of the Salmonella enterica. Here, the genetic diversity of Salmonella enterica isolated from hospital sewage samples of Bangladesh were analyzed to elucidate the prevalence of S. enterica by random amplification of polymorphic DNA (RAPD) and amplified ribosomal DNA restriction analysis (ARDRA). Twenty six isolates were identified as S. enterica by cultural and biochemical methods as well as 16srDNA sequencing. These isolates showed two types of ARDRA and eight distinct RAPD patterns. All of these isolates possessed invA gene. However, agfA and fliC genes were found in 21 isolates and 16 isolates respectively. All of the isolates were resistant to rifamycin but most of them were sensitive to ceftriaxone and streptomycin. The study indicated that the genetic diversity is very high among the S. enterica isolates of Bangladesh. Therefore, such diversity may contribute to the future outbreak of salmonellosis in Bangladesh. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 57-60

Rhizobia are Gram-negative soil-inhabiting bacteria commonly found in nodules of leguminous plants. These bacteria exclusively fix atmospheric nitrogen into ammonia, which is convertible to urea to serve natural fertilizer to the plants. However, rhizobial microbiota of Bangladesh have been studied poorly. Here, twenty isolates were identified as Rhizobium through observation of cultural characteristics, morphological characteristics and different biochemical tests. Isolates differed from one another in terms of their stress response characteristics like salt-stress tolerance,temperature tolerance, antibiotic susceptibility, and pH. Most of the isolates were resistant to ampicillin and erythromycin and streptomycin; and were sensitive to kanamycin and ciprofloxacin. Isolates were clustered into three genotypic groups according to the banding patterns of Amplified Ribosomal DNA Restriction Analysis (ARDRA). All the strains in ARDRA group 1 were Rhizobium azibense, and the others were Rhizobium bangladeshense and Rhizobium qilianshanense. Future studies would validate their capacity of nitrogen fixation and the scope of improvement of these strains to increase their efficiency of nitrogen fixation. Bangladesh J Microbiol, Volume 36 Number 1 June 2019, pp 07-10