Crop storage practices and occurrence of fungi with public health importance from rodents’ trapped inside and outside the storage facilities in Mbeya, Tanzania
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Date
2024-04
Authors
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Publisher
Sokoine University of Agriculture
Abstract
Animals play an important role in the dispersal of seeds and fungal
spores. Several species that consume fruiting bodies of fungi play a
primary role in dispersal networks. Through the rodent-mycorrhizal
dispersal relationship, the study was conducted in selected wards of
urban and peri-urban areas of Mbeya-Tanzania to discover whether
rodents could act as the network for the dispersal of other fungi
related to public health. As well as assessment of knowledge,
awareness, and practices based on storage conditions, that may
influence rodent infestation: implication to fungal contamination in
storage facilities. A total of 210 rodents were trapped in and outside
the storage facilities in selected wards in Mbeya city of which Rattus
rattus (51.0%) was a dominant species, Praomys 40(19.0%),
Lophuromys 29(13.8%), Mastomys natalensis 19(9.0%), Mus
musculus 9(4.2%), and Lemnicomys spp 4(1.9%). Fresh fecal
samples from the rectum were collected. The second form of
samples were 77 pellets collected from the ground making a total
number of 288 fecal pellets. Both samples were preserved at -20 0C
at Mbeya National Research Institute (NIMR) for further laboratory
analysis. Colony morphology obtained through Microbiological
analysis and identification in selective media. A total number of 6
different fungal isolates were observed and Aspergillus fumigatus
was the dominant fungal species from the cultured samples, with a
prevalence of 26% (76/288) showing the potential for aspergillosis in
humans followed by Aspergillus niger and Fusarium species with a
prevalence of 9% (27/288), Aspergillus flavus 3% (10/288) and
Aspergillus ochraceus 1% (4/288). Nested PCR confirmed the
presence of aflR gene from suspected isolates of Aspergillus flavus,
bands observed at 800kb for the first round and 400kb for the
second round. Indirect Competitive ELISA performed on 10 maize
samples that infected with A. flavus isolates, 10 maize samples free
from isolates contamination, and 4 pure isolates of A. flavus. The
aim was to check whether the isolates were capable of producing
toxins and their respective concentrations (ug/ul) were calculated. To confirm the findings a cross-sectional survey was conducted and
a total number of 50 facility storage owners were questioned based
on grains storage practices, factors for rodent infestation, facility-
building conditions, type of material used for storage of grains,
Storage facilities owners’ knowledge based on the effects of rodent
infestation and ways to reduce the effects. Poor storage practices,
types of storage sacks, facility maintenance and longevity of the
facility, and poor knowledge of controlling pests and losses due to
rodents and moulds were the major findings. The 74% of
respondents indicated that they stored only maize, while 26% stored
maize along with other grains such as rice and beans. Among the
respondents, 28% agreed that storing maize with other products
facilitated rodent infestation, 22% disagreed with this opinion, and
the remaining participants were unsure. The 58% of the participants
expressed confidence in their understanding of the factors that
influence rodent infestation, while 42% did not. Regarding major
maintenance of their storage facilities, 38% of the storage keepers
performed it annually, while 20% did it whenever they deemed it
necessary. In terms of rodenticide application within the storage
premises, 54% of the respondents indicated its use.
Description
MSc Dissertation
Keywords
Rodents, fungi PCR, Aspergillus fumigatus, Mbeya