Wednesday, April 29, 2015

Klebsiella spp. Bacteria in Colostrum

Last week we collected ten "as-fed" samples of colostrum on a large dairy. We cultured these colostrum samples on blood agar plates for 48 hours. 

Results? All ten samples contained colonies of Klebsiella bacteria. The lowest colony forming units/ml (cfu/ml) number was 600 cfu/ml and the highest was 7,500 cfu/ml. The farm's upper threshold for Klebsiella bacteria in colostrum is 5,000 cfu/ml. Everyone is unhappy about these results. 

The question of the day: "How is the colostrum being inoculated with this environmental bacteria?"

On a farm visit just one week before we checked both the bottles used to store the colostrum and the esophageal tube feeder used to deliver the colostrum. We used a SystemSURE Plus luminometer that reports back in relative light units (RLU). These RLU's are highly correlated with standard plate counts from bacteria cultures.

The food industry standard upper threshold for RLU's for clean food processing equipment is 10. Our tests for a storage bottle was 0. For the tube feeder the RLU was 1. So,we feel these are an unlikely source of the Klebsiella bacteria. 

That leaves teat preparation failure and the sanitation of the milking equipment as inoculation sources. This week we are planning on checking teat preparation. We have a supply of alcohol pads to wipe the "clean" teat ends before the milking unit is attached.

Also, we have put in place a "pre-milking" sanitizing rinse for the milking unit. [It may be helpful to know that the fresh cows are milked in the calving pen shortly after calving. One milking unit is used to collect all the colostrum.] Our plan is to make a two-gallon chlorine solution (500ppm chlorine) and pull it into the milking bucket through the claw just before collecting colostrum.

After a week to get the new protocols in place we will collect another set of "as-fed" samples and see if we have been successful in shutting down the Klebsiella inoculation of the colostrum.

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