MOLECULAR CHARACTERIZATION OF METHICILLIN RESISTANT Staphylococcus aureus (MRSA) ISOLATED FROM NONO AND YOGHURT CONSUMED IN KADUNA METROPOLIS, KADUNA STATE, NIGERIA
MOLECULAR CHARACTERIZATION OF METHICILLIN RESISTANT Staphylococcus aureus (MRSA) ISOLATED FROM NONO AND YOGHURT CONSUMED IN KADUNA METROPOLIS, KADUNA STATE, NIGERIA
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Date
2016-06
Authors
ABDULRAHMAN, Fausat Adeola
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Abstract
Three hundred and eighty four (384) milk samples (nono and yoghurt) were purchased
from different selling points/vendors/hawkers and were evaluated for the occurrence
ofS.aureus.The physicochemical and proximate analysis (pH, total titrable acidity,
moisture content, protein content, fat content,ash content,) were determined.The results
of the chemical analysis showed that for nono, the pH ranged from 3.56-3.61, total
titratable acidity: 0.71-1.72, moisture content: 82.23-83.87%, total protein content:
1.47-1.58 %, fat content: 0.35-0.38 %, ash content: 0.30-0.31% a. For yoghurt, the pH
ranged from 3.76-3.82, total titratable acidity: 1.10-1.15, moisture content: 77.76-
80.06%, total protein content: 3.38-3.40%, fat content: 1.76-1.79% and ash content:
0.68-0.70% from all the study areas. Out of the 384 Nono and Yoghurt samples
examined,104 samples were contaminated with S.aureus. Out of the 104 isolates of
S.aureusthatwere isolated and identified,88 were coagulase positiveS. aureus.The
Microgen Staph ID kit (Oxoid) was utilised to further confirm the characteristics of the
60 isolates of the coagulase positiveS.aureus.The kit confirmed 43 isolates asS.aureus
and the remaining 17 as other species ofS.aureus which included; S.intermedius,S.
chromogenes,S.hyicus,S.cohnii subsp.urealyticum and
S.heamolyticusrespectively.Twenty of the coagulase positive S.aureus strains were also
investigated for staphylococcal enterotoxins (SE);SEA,SEB,SEC and SED. A total of
19 (95%) of the isolates were found to produce one or more staphylococcal enterotoxin
(SEs). Nineteen of the isolates produced only one type of the SEs with SEA being the
predominant toxins. The antibacterial susceptibility testing was carried out on 43
isolates ofS. aureus. The results showed resistance to Oxacillin
43(100%),Tetracycline10(23.3%),Cefoxitin8(18.6%),Clindamycin10(23.3%),Erythrom
ycin 1(2.3%),Vancomycin 1(2.3%), Chloramphenicol 1(2.3%).All the isolates were
susceptible to Ciprofloxacin.Most of theStaphylococcus aureusisolates tested exhibited
multiple antibiotics resistance (MAR).Twenty (20) isolates ofS.aureusrepresentative of
the study area were selected for genotyping by polymerase chain reaction (PCR) to
detect the mecA gene.Only 1 of the 20 isolates was genotypically confirmed as MRSA
positive. The results indicated the presence of S.aureus in the milk samples,
antimicrobial resistance strains ofS.aureus, enterotoxigenicstrains ofS. aureus and
presence of MRSA in the milk samples which are of public health importance. As all
these can contribute to foodborne intoxication which can lead to food poisoning.
Therefore there is need for better control of the spread of the antibiotics resistant strains
as well as milk samples contamination sources. There should be proper pasteurisation
of raw milk and fermentation of milk to help eliminate MRSA before human
consumption.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POST GRADUATE
STUDIES AHMADU BELLO UNIVERSITY
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD
OF THE MASTER OF SCIENCE IN MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY,
FACULTY OF SCIENCE,
AHMADU BELLO UNIVERSITY,
ZARIA, NIGERIA.
Keywords
MOLECULAR CHARACTERIZATION,, METHICILLIN RESISTANT,, Staphylococcus aureus,, ISOLATED,, NONO,, YOGHURT CONSUMED,, KADUNA METROPOLIS,, KADUNA STATE,, NIGERIA