Fig 1.
Schematic illustration for samples preparation, spiking with M. avium subsp. avium and decontamination with six procedures.
Fig 2.
Schematic illustration for fresh fecal samples preparation and decontamination with six procedures.
Fig 3.
Number of tubes showing growth of M. avium subsp avium recovered from spiked fecal samples after six decontamination procedures.
Bars show sum of AFB positive cultures, AFB negative cultures and contaminated cultures obtained from three inocula. When decontaminants were followed by VNA, a decrease in contamination rate was observed with all procedures, however the proportion of positive cultures increased with CPC 1%.
Table 1.
P-values obtained by comparing six cultures procedures for the growth of M. avium subsp avium from spiked fecal cultures.
Table 2.
Mean colonies count and number of weeks for first appearance of growth of M. avium from spiked samples decontaminated using 6 procedures.
Fig 4.
Number of tubes showing growth of mycobacteria recovered from field avian fecal samples using different decontamination procedures.
Incorporation of VNA minimized the contamination of cultures in all procedures. However, VNA in NaOH significantly reduced the proportion of contaminated cultures (59.5%; χ2 test p = 0.0001) and CPC (50%; χ2 test p = 0.003).
Fig 5.
Gel picture of PCR (16S rRNA) of mycobacteria isolated from field samples.
M, 100 bp molecular DNA marker; C+ positive control (M. avium subsp. avium ATCC 15769), C- negative control (sterile water); 1 and 2 (564 bp) positive samples from chicken.