Comparative antimicrobial activity in Murrah buffalo (Bubalus bubalis) Heifers’ urine and urine distillate

Background:Murrah buffalo is a breed of water buffalo(Bubalus bubalis)reared for milk and meat,especially in Northern India.There are so many studies on the antimicrobial potential of the cow(Bos indicus)urine but buffalo urine has rarely been studied.This study was aimed to evaluate the antimicrobial activity in whole buffalo urine and its distillate.Methods:Urine specimens were collected from seven Murrah buffalo heifers in the morning over three days from all seven heifers and distillated to prepare urine distillate(UD).The antimicrobial activity was determined through 96 well microplate method diluting(1:1)urine and UD in Mueller Hinton liquid medium against 919 microbial strains belonging to 148 species of 49 genera(Candia,11 genera of Gram+ve bacteria,37 genera of Gram-ve bacteria).The test strains were taken from the repository,revived and tested for purity before testing.The test strains were of clinical origin(372),environmental origin(496)and also from reference strain repositories(51).Results:Of the 919 test strains,a total of 57.89%and 56.04%of the tested strains were susceptible to UD and urine,respectively.There was a no significant(p>0.4)difference in the antimicrobial activity of UD and urine against 919 strains of microbes,regardless of their genus,species,and Gram staining reaction.Similarly,there was no significant(p>0.4)difference between the susceptibility of bacterial and Candida strains to UD or urine.However,strains of clinical origin were more often resistant to buffalo UD and urine(p<0.01)than strains isolated from environmental sources irrespective of their Gram staining characteristics(p>0.05).A significantly(p<0.01)higher proportion of reference strains was susceptible to UD and urine than microbial strains of clinical and environmental origin.For buffalo urine and UD,the most susceptible strains were Stenotrophomonas maltophilia(13/13)followed by Citrobacter freundii(8/10);Salmonella enterica ssp.enterica(21/27),Geobacillus stearothermophilus(23/30),Staphylococcus aureus(13/17),and Paenibacillus larvae(7/10)strains.The most resistant strains belonged to Acinetobacter calcoaceticus(15/20)species followed by strains of Paenibacillus alvei(11/16),Edwardsiella tarda(20/30),Bacillus megaterium(7/11)and Escherichia coli(59/110)species.There was insignificant(p,>0.05)difference in susceptibility of strains of different species of the same genus;however,among all the Bacillus species strains of B.coagulans were the most susceptible(66.7%)and strains of B.megaterium were the least susceptible(36.4%),similarly Enterococcus faecium strains were more susceptible(68.2%)than strains of Enterococcus faecalis(38.9%),70%strains of P.larvae were susceptible to urine and UD but only 31.3%of strains of P.alvei were susceptible.Strains of Klebsiella pneumoniae and Raoultella terrigena,earlier belonging to the same genus Klebsiella,had comparable susceptibility to buffalo urine and UD.Conclusion:The study concluded that buffalo urine may be a potential antimicrobial and may be explored further for identification of active antimicrobial compounds in buffalo urine.