BACTERIANA Y DE HONGOS EN LA CAMA AVICOLA
- Sakchai Himathongkham, Hans Riemann, and Ram Saini
Department of Population Health and Reproduction, School of Veterinary Medicine
University of California, Davis, CA 95616
Preserve International, P.O. Box 3135. Turlock, CA 95381
RESUMEN
La aspersion de la cama en las casetas de los pollos de engorda con Dvne-O-Might (un producto desinfectante ácido) incrementó inmediatamente,
1,000 veces, la acidez de Ia superficie (reducción de 3 puntos en el pH) y, 72 horas despues, la acidez continuaba siendo 10 veces mas alta que antes de Ia aplicación del tmtamiento. Esta aspersion redujo el
conteo total de bacterias viables (Clostridiurn perfringens y Escherzch:a coil) y de hongos en más de un 90%, en promedlo. Las cantidades de salmonelas fueron consistentemente bajas.
INTRODUCTION
Most pathogenic microorganism do not survive well in the deeper layer of old litter; probably because of accumulation of ammonia and reduction of oxygen resulting from the activity of saprophytic microorganism6.
The surface of the litter represents a risk; here pathogenic bacteria are deposited and mold can produce spores. The application of a liquid acid complex to the surface of litter is a potentially effective method to
reduce the numbers of pathogenic microorganisms Most of the disinfectants approved for use in poultry houses cannot efficiently kill microorganisms in the litter because of the high load of organic matter. Formaldehyde
is a very potent disinfectant;however, it causes irritation and is a potential carcinogen 2.4.5. Dyne-O-Might seems to be a good alternative to formaldehyde. Dyne-O-Might is composed of organic acids that are
recognized by FDA as GRAS (General Recognized As Sale) and are not carcinogenic. In this study its effect on microorganisms on the surface of broilers chicken litter was measured.
MATERIALS AND METHODS
Two poultry houses with litter of wood shavings on which 3 flocks of broilers had been raised were used in the study. Sterile drag swabs3 moistened with double strength skim milk were used for surface sampling of litter
and walls: approximately 0.84 square meter was covered by each swab. Forty swabs were used to sample the floor (152 x 12 meters) and 10 swabs to sample the walls just above the floor. The swabs were combined in numbers
of 5 and placed in sterile whirl-pak bags. To each bag was added 100 ml sterile 1% proteose peptone which after shaking was plated on nutrient agar (for total plate count), eosinmethylene blue agar (for E.
coil),brilliant green novobiocin agar (for salmonellae), tryptose-sulfite cvcloserin egg yolk agar (for Clostridium perfringens) and sabouraud agar (for yeast and mold). Ten ml of the liquid in the whirl- pak bags
were transferred to 2 whirl-pak bags with 90 ml protease peptone and 2 more 10-fold dilutions were made in duplicate for most probable number estimation. The whirl-pak bags were incubated for 20 hr at 370C. The
pre-enrichment broth was culture in tetrathionate broth for 24 hr at 370C and streaked on brilliant green novobiocin agar that was incubated for 48 hr at 370C for detection of salmonellae. Suspect colonies were
inoculated on triple sugar iron agar for confirmation.
The 2 houses were sampled for bacteria on March 4, 1994 and again on March 15, 3 days after spraying with Dyne-O-Might solution. A second test for mold
was done on May 19, at this time only floors were sampled and only I hr or less elapsed between spraying and sampling for mold and acidity test (pH).
RESULTS AND DISCUSSION
Bacterial and mold counts and
pH values in litter are shown in Figure 1. There was a consistent decrease in microbial counts after spraying with Dyne-O-Might. The counts of E. coli were low, only around 100 per swab, even before spraying and the
counts of salmonellae were too low, 1-3 per swab, to permit conclusions. However, total aerobic counts (over 100 millions) and C perfringens counts (between 1000 and 10000) before spraying were high enough to
demonstrate significant reduction. Spraying reduced pH temporarily to very low values which probably explains the killing effect (Figure 2).
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