title: Recombinant Lactobacillus plantarum expressing and secreting heterologous oxalate decarboxylase prevents renal calcium oxalate stone deposition in experimental rats.
abstract: BACKGROUND
  Calcium oxalate (CaOx) is the major constituent of about 75% of all urinary stone and the secondary hyperoxaluria is a primary risk factor. Current treatment options for the patients with hyperoxaluria and CaOx stone diseases are limited. Oxalate degrading bacteria might have beneficial effects on urinary oxalate excretion resulting from decreased intestinal oxalate concentration and absorption. Thus, the aim of the present study is to examine the in vivo oxalate degrading ability of genetically engineered Lactobacillus plantarum (L. plantarum) that constitutively expressing and secreting heterologous oxalate decarboxylase (OxdC) for prevention of CaOx stone formation in rats. The recombinants strain of L. plantarum that constitutively secreting (WCFS1OxdC) and non-secreting (NC8OxdC) OxdC has been developed by using expression vector pSIP401. The in vivo oxalate degradation ability for this recombinants strain was carried out in a male wistar albino rats. The group I control; groups II, III, IV and V rats were fed with 5% potassium oxalate diet and 14th day onwards group II, III, IV and V were received esophageal gavage of L. plantarum WCFS1, WCFS1OxdC and NC8OxdC respectively for 2-week period. The urinary and serum biochemistry and histopathology of the kidney were carried out. The experimental data were analyzed using one-way ANOVA followed by Duncan's multiple-range test.
  
  
  RESULTS
  Recombinants L. plantarum constitutively express and secretes the functional OxdC and could degrade the oxalate up to 70-77% under in vitro. The recombinant bacterial treated rats in groups IV and V showed significant reduction of urinary oxalate, calcium, uric acid, creatinine and serum uric acid, BUN/creatinine ratio compared to group II and III rats (P < 0.05). Oxalate levels in kidney homogenate of groups IV and V were showed significant reduction than group II and III rats (P < 0.05). Microscopic observations revealed a high score (4+) of CaOx crystal in kidneys of groups II and III, whereas no crystal in group IV and a lower score (1+) in group V.
  
  
  CONCLUSIONS
  The present results indicate that artificial colonization of recombinant strain, WCFS1OxdC and NC8OxdC, capable of reduce urinary oxalate excretion and CaOx crystal deposition by increased intestinal oxalate degradation.
authors.forename: Ponnusamy
authors.initials: P
authors.lastname: Sasikumar
authors.forename: Sivasamy
authors.initials: S
authors.lastname: Gomathi
authors.forename: Kolandaswamy
authors.initials: K
authors.lastname: Anbazhagan
authors.forename: Albert
authors.initials: A
authors.lastname: Abhishek
authors.forename: Eldho
authors.initials: E
authors.lastname: Paul
authors.forename: Varadaraj
authors.initials: V
authors.lastname: Vasudevan
authors.forename: Sundaresan
authors.initials: S
authors.lastname: Sasikumar
authors.affiliation: Department of Biochemistry, Centre for Advanced Studies in Organismal and Functional Genomics, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India. drselvamgsbiochem@rediffmail.com.
authors.forename: Govindan Sadasivam
authors.initials: GS
authors.lastname: Selvam
mesh_terms: D000818:Animals; D002129:Calcium Oxalate / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D006959:Hyperoxaluria / Q000139:chemically induced / Q000517:prevention & control* / Q000652:urine; D007669:Kidney Calculi / Q000139:chemically induced / Q000517:prevention & control* / Q000652:urine; D048191:Lactiplantibacillus plantarum / Q000201:enzymology* / Q000235:genetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D002129:Calcium Oxalate; D002262:Carboxy-Lyases; C021915:oxalate decarboxylase