TONUI K JOSEPHAT

MSC. STUDENT

JKUAT- COHES

SUPERVISORS

DR. CHRISTINE BII (PhD)

DR. CIIRA KIIYUKIA (PhD)

2014

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* Introduction

More than 100, 000 moulds spp produce over 300 mycotoxins contaminanting food grains

Genera Aspergillus, Penicillium, and Fusarium major contaminants of maize

Produce aflatoxins, ochratoxins and Fumonisins with toxic and carcinogenic potential

Fungicides are chemical compounds against fungi

They affect fungal nucleic acid and sterol biosynthesis, mitosis and cell division, respiration etc.

Several bacterial and fungal antagonists have been developed for the control of Mycotoxigenic fungi

Mycotoxins cause health and economic problems in the

world affecting humans, animals and the environment

Aspergillus flavus and A. parasiticus producing

Aflatoxins are a major problem in Kenya

Largest aflatoxicosis outbreak in 2004 resulted in 125

deaths & 317 cases in Eastern province, Kenya

Tones of maize grain yields have been destroyed

intermittently

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General objective

To determine the susceptibility of mycotoxigenic

fungi to some commercial fungicides as a potential

for the control of mycotoxin infestation in maize

Specific Objectives

1.To isolate and identify mycotoxigenic fungi

affecting maize grains from Machakos, Nairobi,

Mombasa, Kisumu and Kitale.

2.To determine the susceptibility of the

mycotoxigenic fungal isolates to Atracol, Milraz,

Mistress and Victory fungicides.

* Objectives

Study design A laboratory based cross sectional study.

A total of 138 maize samples from the five sites were collected

Conducted at KEMRI Center for Microbiology Research- Mycology Laboratory

Procedures Fungicides diluted according to manufacturers instructions

Fungicide was applied onto four maize Kernels and inoculated on SDA media, incubated at 30oC for 72 hours for fungal growth.

Fungal growth identified morphologically (Microscopic and Macroscopic features) and scored to determine percentage Infestation

Activity of fungicides was determined by Disk Diffusion

* Materials and Methods

* Results

Percentage fungal infestation of maize from different

regions in Kenya following treatment of grains with

fungicides

*

Infestation

rates on

maize

Type of fungicide used

Categories MILRAZ MISTRESS VICTORY ANTRACOL CONTROL

0 % within type of

fungicide used

10%

n=14

26%

N=35

34%

N=47

14%

N=19

0%

N=0

25 % within type of

fungicide used

21%

N=29

27%

N=37

19%

N=26

24%

N=33

4%

N=5

50 % within type of

fungicide used

12%

N=17

12%

N=17

18%

N=25

15%

N=21

5%

N=7

75 % within type of

fungicide used

17%

N=23

14%

N=19

8%

N=11

8%

N=11

8%

N=11

100 % within type of

fungicide used

40%

N=55

22%

N=30

21%

N=29

39%

N=54

83%

N=115

Total % within type of

fungicide used

100%

n=138

100%

N=138

100%

N=138

100%

N=138

100%

n=138

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Plate A . Aspergillus niger Plate B. Fusarium and A. flavus

Plate C. Heavily infested untreated

control and treated maize Plate A . Aspergillus

flavus infested maize

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Maize from the five regions were contaminated by mycotoxin producing moulds of the genera Aspergillus spp, Fusarium spp and Penicillium spp.

There was a significant difference p<0.05 in the activity of the four fungicides.

Generally, a significant percentage of maize treated with Mistress and Victory (n=35) and (n=47) respectively were less infested.

The two fungicides were more effective in reducing the fungal infestation on the treated maize samples.

N=55 and N=54 samples treated with Milraz and Antracol respectively had 100% infestation compared to those treated with Victory and Mistress Fungicides (n=29) and (n=30) respectively.

* Discussion

Some isolates of A. flavus, Fusarium spp and Penicillium

spp exhibited resistance to at least one of the test fungicides.

Shown by overgrowth of the mould on fungicide

impregnated disks and absence of a zone of inhibition

This is indicative of emerging resistance to commercial

fungicides.

However, more studies on the emerging resistance to more

fungicides country wide may be necessary.

* Discussion Cont..

The four test fungicides were effective in reducing fungal infestation of maize a potential for mycotoxin control

Further evaluation to ascertain their field efficacy needed.

Some isolates showed resistance to the test fungicides probably due to irrational use of fungicides.

Emerging triazole resistance in A. fumigatus linked to azole antifungals used in agriculture.

Calls for rational use of fungicides in agriculture to avoid emerging resistance in clinical practice

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We acknowledge Kenya Medical Research

Institute (KEMRI) for approval and funding for

this work under mycotoxin surveillance program.

We also acknowledge the Jomo Kenyatta

University of Agriculture and Technology (JKUAT)

for reviewing this work

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