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Introduction
Coliform bacteria are a diverse group of Gram-negative, non-
spore-forming rod-shaped bacteria that are predominantly found in
the intestines of warm-blooded animals, including ruminants such as
cows. They are classified into three primary groups: total coliforms,
faecal coliforms, and Escherichia coli. The presence of coliforms in
the environment is often used as an indicator of faecal contamination,
making them significant in food safety and public health contexts.
1
Understanding the ecology of coliforms in the rumen of cows is
essential for assessing not only animal health and productivity but
also the implications for food safety related to human consumption
of animal products.
The rumen is a specialized compartment of the digestive system in
ruminants, playing a crucial role in the fermentation of fibrous plant
materials. The microbial population in the rumen consists of various
microorganisms, including bacteria, archaea, fungi, and protozoa, all
of which contribute to the breakdown of complex carbohydrates and
proteins.
2
Coliforms, although often considered minor components of
the rumen microbiota, play vital roles in this complex ecosystem. They
are involved in the fermentation process, facilitating the breakdown
of cellulose and other polysaccharides into simpler compounds,
including volatile fatty acids (VFAs), which serve as primary energy
sources for ruminants.
Furthermore, coliforms can participate in nitrogen metabolism
within the rumen, influencing protein synthesis and amino acid
availability for the host.
3
Their presence can help maintain a balanced
microbial community, promoting optimal digestion and nutrient
absorption, which are critical for the overall health and productivity
of ruminants. Coliforms are primarily categorized into three groups:
total coliforms, faecal coliforms, and Escherichia coli. Total coliforms
include a broad spectrum of bacteria that may originate from both
faecal and non-faecal sources, whereas faecal coliforms are specifically
derived from the intestines of warm-blooded animals, indicating
faecal contamination.
1
Among these, E. coli includes both pathogenic
and non-pathogenic strains, making it a significant focus for food
safety research. The presence of coliforms in the rumen is not only
indicative of faecal contamination but also reflects the overall health
of the ruminant and the microbial community’s balance. Coliforms
contribute to the fermentation process within the rumen, where they
assist in breaking down fibrous plant material and converting it into
simpler sugars, fatty acids, and gases.
1
These fermentation products
are essential for the energy metabolism of ruminants.
Materials and methods
Sample Collection and Processing
Two samples (Rumen) from two slaughtered cows from the Afor-
Obah market was collected using two sterilized plastic buckets.
The buckets were sterilized by first washing them with detergent,
air-dry and rinsed with 95% ethanol. The samples were transported
to the laboratory within 2 hrs of collection. The liquid content of
rumen was aseptically squeezed into an already sterilized conical
flask. Thereafter, 10 ml of each was mixed with 100 ml of sterilized
distilled water. This forms a stock solution for serial dilution. Ten-fold
serial dilution was done by initially using 1 m of the stock solution.
Finally, 10
2
, 10
4
and 10
6
diluents were spread plated out on Maconkey
and Eosin Methylene blue agar. These were done in duplicates and
incubated for 24hrs at 37
o
C.
Results
After the incubation period of 24hrs, the following results were
obtained and biochemical identification analysis conducted on the
isolates (Figures 1&2) (Tables 1&2).
Table 1 colony count for the two media and samples
Samples
Total Colonies Count On
Macconkey (Cfu/ml )
Total Colonies Count on
EMB (Cfu/ml)
10
2
10
4
10
6
10
2
10
4
10
6
1 4.0×10
4
3.0 ×10
6
3.0 ×10
8
2.0×10
4
8.0×10
6
3.0×10
8
2 6.0×10
4
9.0×10⁶ 9.0×10
8
3.0 ×10
7
9.0×10
7
5.0×10
8
J Microbiol Exp. 2025;13(2):30‒32. 30
©2025 Osuji et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and build upon your work non-commercially.
Isolation and identification of coliform from the
Rumen of cows slaughtered at Afor-Oba abattoirs in
Anambra
Volume 13 Issue 2 - 2025
1
Department of Microbiology, Faculty of Natural and Applied
Sciences Spiritan University Nneochi Abia State Nigeria
2
Department of Medical Microbiology, Faculty of Medical
Laboratory Science, Nnamdi Azikiwe University Nnewi Campus,
Anambra State, Nigeria.
3
Department of Microbiology, Faculty of natural and applied
science Legacy University Okija Anambra State Nigeria
Correspondence: Osuji Malachy Ikeokwu, Department of
Microbiology, Faculty of Natural and Applied Sciences Spiritan
University Nneochi Abia State Nigeria, Tel +2348034006542
Received: April 01, 2025 | Published: April 21, 2025
Abstract
This research was conducted to ascertain the coliform resident in the rumen of slaughtered
cow. Two samples were aseptically collected and processed. Ten-fold serial dilution was
done and 102, 104 and 106 diluents were spread plated on Maconkey and Eosin methylene
blue agar. After 24hrs of incubation at 37 0C, ( 4.0×10
4
, 3.0 ×10
6
, 3.0 ×10
8
;) ( 6.0×10
4
; 9.0×10⁶, 9.0×10
8
)cfu/ml were recorded for Maconkey for sample 1 &2 respectively.
Also (2.0×10
4
8.0×10
6
3.0×10
8;
),( 3.0 ×107, 9.0×10
7
, 9.0×10
7
) cfu/ml was counted for
Eosin methylene blue for samples 1 & 2 respectively. After isolation and identification,
Escherichia coli, Klebsiella pneumonia, Enterobacter spp and Citrobacter sp were identified
as possible organisms. Of the possible organisms, Escherichia coli and Citrobacter sp
were predominant. Further visit to the ranch revealed that several negative factors were
responsible for the presence of the pathogenic organisms. These factors are to be corrected
and consumers are advised to cook the meat very well before eating.
Keywords: Abatoir, coliform, colony, incubation, rumen. ruminant
Journal of Microbiology & Experimentation
Research Article Open Access