Abstract:
Identification of pathogens is a crucial step in the diagnosis of livestock diseases. An
insight of bacterial diversity may enable decisions on appropriate treatment and shield
farmers from tremendous losses due to disease outbreaks. The aim of this study was
to investigate the occurence and diversity of pathogenic bacteria in the environment at
University of Limpopo experiential farm using Matrix Assisted Laser Desorption
Ionization-Time of Flight Mass Spctrometry (MALDI-TOF MS). The diversity of
pathogenic bacteria were investigated in environmental samples collected from three
different sampling locations within the farm (labelled according to the site of collections
as cattle camp (CC), sheep camp (SHC), and goat camp (GC)). Total bacterial counts
were calculated using the colony forming unit formula per gram of environmental
sample (CFU/g) with the standard spread plate method. High bacterial counts were
observed in CC: 7.25x107 cfu/g and 4.5x106 cfu/g for soil and faecal samples
respectively while low counts were observed in SHC: 4.8x107cfu/g for soil samples
and 3.7x106 cfu/g for faecal samples) for both soil and faecal samples. In soil samples,
similar bacterial species were encountered at the different sampling locations. Bacillus
species (B. cereus, B. megaterium, B. simplex, B. mycoids, B. weihenstephansis, B.
licheniformis and B. endophyticus) were the most dominant across the different
sampling locations in the soil samples. Bacillus cereus tested positive in 36 samples
(33 %), however, the frequency of isolation dominated in the GC (50 %), SHC (41.6
%) CC with (28 %), and Staphylococcus aureus were the least isolated with a
frequency of 1.4 % followed by Listeria monocytogens with 2.8 % frequency in CC. In
faecal samples, the occurrence and level of contamination with bacterial species varied
across sampling locations with minor similarities observed in SHC and GC. Escherichia
coli dominanted CC with 64.2 % frequency, and absent from SHC and GC. This study
demonstrated the contamination of opportunistic, food borne bacteria like B.cereus and
L. monocytogenes in the experiential farm environment and the need for good hygiene
practices to prevent its entry into the food chain
