1. The University of Zambia
School of veterinary medicine
Department of paraclinical studies
Name: Musalo Brian
Computer #: 10008047
Course code: VMP-4300 (Immunology & Bacteriology)
Lab: serological test on Brucella abortus and Salmonella
Attention: Mr.mubita
Date: 17/02/14
Copyright: Musalo Brian Chisanga|Bacteriology/Immunology Lab Report|2014|

2. Title: serological tests on Brucellosis and Salmonella
Copyright: Musalo Brian Chisanga|Bacteriology/Immunology Lab Report|2014|
Aim:
 To determine the presence of antibodies against brucellosis using rose Bengal Brucella
abortus.
 To confirm Salmonella pathogens using salmonella polyvalent ‘o’ anti-serum.
INTRODUCTION
Brucella are coccoid, gram-negative rod-shaped bacteria that lack flagella and be readily cultured
under strict aerobic conditions on enriched nutrient mediums such as blood agar. The genera
Brucella consists Brucella abortus, B.melitensis & B.suis which cause a condition that manifests
as Brucellosis. In this practical the focus is only on the specie Brucella abortus. Brucellosis is a
classical zoonosis that affects cattle (B. abortus), goats (B.melitensis) and pigs (B.suis). The
pathogen can be transmitted directly from diseased animals to humans and indirectly via food
causing a uniform clinical picture, so called Undulant fever or Bangs disease. Brucellosis causes
reticuloendothelia system granulomas and diagnosis is by means of pathogens identification or
antibody assay using standardized agglutination reaction (F.H. kayser, 2005).
All Salmonella are classified in the species salmonella enterica with seven subspecies. Nearly all
human pathogens are grouped under salmonella enterica and subspecie enterica. Salmonella are
further subclassified in over 2000 serovars based on their O & H antigens. Enteric salmonellosis
is a condition that develops when pathogens are taken up through food. However, the primary
infection source is usually livestock. The method of diagnosis is by detection of pathogens in
cultures where a selective indicator mediums are used to separate salmonella from a source i.e.
stool (F.H. kayser, 2005).
The method of diagnosis used in this experiment involves Serology which basically refers to the
identification of antibodies of a specific antigen in a patient’s serum. Another r diagnostic
methods that is commonly used is microscopy. Diagnosis is of immediate clinical relevance to
the patients’ treatment (Hawkey M.P, 1989).

3. MATERIAL
 Serum
 Rose Bengal Brucella abortus
 salmonella polyvalent ‘o’ anti-serum
 antigens
 known positive control
 known negative control
 rose Bengal plate (well)
 medicine dropper
 Timer
 Microscope
 Microscope glass slide
 Loop
 Sample X on a culture plate
 Sample Y on a culture plate
PROCEDURE
 Brucella test procedure
 25 microliters of antigen was added into all the 5 wells of the rose Bengal plate
 On the negative well 25 microliters of a negative control liquid was added and mixing
was done
 25 microliters of the known positive control liquid was added into the positive well
and mixing was done
 25 microliters of each sample, X, Y and Z were added onto their wells respectively
and gently rocking was done for 5 minutes.
 Salmonella test procedure
 2 drops of polyvalent ‘o’ antiserum were added on a slide using a medicine dropper
 A loop full of sample X was gotten from the culture plate containing sample X and
put on the center of one half of the slide.
 On the other half of the slide, a loop full of sample Y gotten from a culture plate
containing sample Y was added
Copyright: Musalo Brian Chisanga|Bacteriology/Immunology Lab Report|2014|

4.  Gently rocking was done for 5 minutes.
RESULTS
Fig1. Showing results obtained from Brucella abortus test
PRESENCE SAMPLES
Sample X Sample Y Sample Z
Negative (-) 
Positive (+)  
Fig2. Showing the results obtained from the salmonella test
PRESENCE SAMPLES
Sample X Sample Y
Negative (-) 
Positive (+) 
DISCUSSION
The Brucella test indicated that samples X and Y were positive while sample Z showed negative.
This means that samples X & Y showed the presence of antibodies that are specific to rose
Bengal Brucella abortus a causative agent of brucellosis, a condition commonly found in cattle
and can be transmitted to humans directly by contact or indirectly by way of contaminated food
such as unpasteurized milk and dairy products. The diagnosis of Brucella abortus is generally
achieved by isolation of pathogens from blood or biopsies in cultures, which must be incubated
for 4 weeks. These Brucella were identified based on various metabolic properties and presence
of surface antigens, which were detected using a known rose Bengal Brucella abortus
(polyvalent ‘o’ Brucella-antiserum can also be used) in a plate agglutination reaction. In doubtful
cases, the complement-binding reaction and direct combs test can be applied to obtain
serological diagnosis. The epidemiology of Brucellosis is zoonotic and affects all animals all
over the world. Treatment therapy that is recommended is the administration of doxycycline in
the acute phase, often in combination with gentamicin.
The salmonella test indicated that the sample X, was positive and sample Y is negative. The
interpretation is that sample X contains evidence of salmonella pathogens (antigens) while
sample Y had none. Pathogenically salmonella is classified as either typhoid or enteric regarding
the clinical relevant pictures and epidemiologies. Salmonella typhoid only causes systemic
Copyright: Musalo Brian Chisanga|Bacteriology/Immunology Lab Report|2014|

5. diseases in humans, whereas enteric salmonella infections occur in animals as well and are
usually restricted to the intestinal tract. The method of choice of diagnosis is detection of the
pathogens from a selective indicator medium, this is done using metabolic patterns. Typhoid
salmonellosis can be diagnosed indirectly by measuring the titer of agglutinat ing antibodies to O
& H antigen (F.H. kayser, 2005).
CONCLUSION
The Brucella test indicated that samples X and Y were positive while sample Z showed negative
of Brucella abortus. In the salmonella test the sample X was positive and sample Y is negative of
Salmonella bacteria.
REFERENCES
 Blood D.C & Studdert P.V, 1988, Bailliere tinda comprehensive veterinary dictionary, 1st
edition, Bailliere tinda, Saunders, pages 8,242.
 Kayser F.H, Bienz K.A, Enkert K, Zinkernagel R.M, 2005, medical microbiology, New
York, USA.
 Hawkey M.P and Lewis A.D, 1989, medical bacteriology and practical approach, IRC
Press at oxford university press, England, page8.
 Nester W.E et al, 2004, microbiology: A human perspective, 4th edition, McGraw Hill,
New York, pages 83, 84, and 94.
 DIFCO Manual: Dehydrated Culture Media and Reagents, 10th Edition. (Difco
Laboratories: Detroit) ©1984, Pp. 543, 546, 616, 1023.
Copyright: Musalo Brian Chisanga|Bacteriology/Immunology Lab Report|2014|