Detection,Identification And Sequence Analysis Of Burkholderia Gladioli In Corn Flour Products And Related Samples

Burkholderia gladioli is a widely-existing bacterium.Some of the strains produce bongkrekic acid and toxic flavin.In the 1970 s and 1980 s,the food poisoning of Pseudomonas cocovenenans(previously used)in China was more common and severely reported.After that,the related research was rare,but it has not been possible to eliminate such bacterial food.The occurrence of poisoning incidents and the high mortality rate.The in-depth study of the bacteria by modern means has theoretical and practical value.13 suspected Burkholderia gladioli strains were isolated from food and environmental samples.Then we used biochemical tests,Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry(MALDITOF MS)and recA sequence analysis to identify those strains.All 13 suspected strains were identified as B.gladioli by MALDITOF MS and recA sequence analysis.But only 8 were identified as B.gladioli by biochemical test,while another 5 were identified as Pseudomonas oryzihabitans.The identification results by MALDITOF MS are agreed with the recA sequence analysis.But VITEK 2 COMPACT biochemical test method has inherent flaws.RecA sequence analysis and MALDI-TOF MS are more accurate,rapid and cheaper than traditional biochemical test method in B.gladioli identification.In this study,we used the multi-site sequence typing(MLST).Alleles of 6 housekeeping genes from 13 isolates of our laboratory were detected,gyrB's mutation rate was the highest,and 5 strains of 13 strains had new alleles,the mutation rate reached 38.5%,while atpD and gltB were relatively conservative,and no new housekeeping genotype was found.After the multi-gene combination of 6 pairs of genes,it was proved that 6 housekeeping genes can distinguish the pathogenic strains in the genus Burkholderia from the environmental isolates.The mouse toxicity test,liquid chromatography-mass spectrometry and rapid detection technology were used to determine the Bongkrekic Acid,and the crude test was carried out by spectrophotometry.There is no difference in the amount of the two toxins from the region,but it can be seen that the isolate has a strong ability to produce poison.The growth curves of B.gladioli YD-2 and B.gladioli CICC 10574 isolated from food poisoning cases were tested.The growth of the two strains was similar.When cultured at 37?,the strain grew most vigorously at pH 5.05.At pH 4 and pH 7,the strain grew very slowly.Enter the logarithmic period from 12 to 32 h.