The Susceptibility of Swine Abortion-Associated Leptospira hyos to Disinfectants
Author(s): Gemerlyn G Garcia, Apol Joann Guimpayan, Lara Joy Baysa, Lilibeth L Gumpal
Evaluation on the sensitivity of the S-shaped and hook-ended swine abortion-associated Leptospira hyos to disinfectants was undertaken and validated by monitoring recovery counts in McFarland units (MFU). The disinfectants for evaluation included phenol, quaternary ammonium, formaldehyde, chlorine and potassium alum, each prepared in 10, 25 and 50% solutions in sterile deionized water and the pathogen reaction to the disinfectants was evaluated after 30 min and 1 hr exposure time. Results show that in the first 30 min, comparably higher L. hyos MFU was associated with the application of 10 and 25% phenol compared to significantly lower MFUs obtained with 50% phenol. The susceptibility of L. hyos to quaternary ammonium was shown by comparably higher MFUs relative to the application of 10 and 25% quaternary ammonium in contrast to the significantly lower MFU relative to the application of a higher quaternary ammonium concentration (50%). Higher L. hyos MFU was also associated with the application of 10% formaldehyde in contrast to the significantly lower MFU obtained relative to 25% formaldehyde application, with the least MFU linked with the 50% formaldehyde concentration. A trend marked by significantly higher L. hyos MFU was linked to the application of 10% chlorine, a lower MFU associated with 25% chlorine, while the least MFU recorded with 50% chlorine. The application 10 and 20% potassium alum contributed to comparable and significantly higher L. hyos MFU contrary to nil MFU related with 50% potassium alum application. Data obtained after 1 hr application of phenol, quaternary ammonium, formaldehyde, chlorine and potassium alum in 10%, 25% and 50% concentrations contributed to the recorded nil MFUs of L. hyos compared to data obtained in the first 30-minute exposure. These data highlight the significant action of the disinfectants on L. hyos which were apparently activated by disinfectant concentration and duration of exposure.