ABSTRACT
This study investigated the incidence, molecular characters and sensitivity to Buchholzia
coriacea leaf extract, of methicillin-resistant Staphylococcus aureus (MRSA) nasal isolates
from tertiary institution students in Delta State. Nasal swabs were collected with sterile swab
sticks from nine hundred (900) apparently healthy students in the study areas and cultured on
mannitol salt agar. The bacterial isolates (S. aureus) were Gram-stained, and the Gram positive
isolates subjected to catalase test. The catalase - positive isolates were subjected to coagulase
test and the coagulate positive isolates further subjected to DNase test for confirmation. The
MRSAs were detected using oxacillin antibiotic disk (1 μg). Antimicrobial susceptibility profile
of the MRSA isolates was determined according to the Clinical Laboratory Standard Institute
(CLSI) Guidelines. The Kirby-Bauer method was employed to determine the susceptibility of
the MRSA isolates to vancomycin. The minimum inhibitory concentrations (MICs) and
minimum bactericidal concentrations (MBCs) of some antibiotics and the extracts were
evaluated using agar dilution method. Tests were carried out to determine the presence of
penicillin binding protein2a (PBP2a). The MRSA isolates were screened to determine their
biofilm producing ability. Reverse Passive Latex Agglutination test was carried out to detect the
presence of enterotoxins among the MRSA isolates. The methanoic and aqueous leaf extracts of
Buchholzia coriacea leaf were prepared from standard protocols. Phytochemical constituents of
extract and antimicrobial screening against the MRSAs were carried out according to standard
methods. Molecular characterization of MRSA isolates was carried out to determine the
presence of the mecA genes among the isolates. Statistical analysis was done using analysis of
variance (ANOVA). Out of the nine hundred nasal samples collected from three different study
locations and screened, a total of 600 (66.7%) were positive for S. aureus, based on morphology
and biochemical tests. The incidence of S. aureus colonization among female and male
individuals was 313(34.7%) and 287 (31.9%), respectively. There was no significant difference
(p>0.05) in the females (52.2%) and males (47.8%). The antibiotic resistance pattern of the
MRSA isolates was: amoxicillin > streptomycin > amoxicillin/clavulanic acid > erythromycin
> chloramphenicol > co-trimoxazole > ofloxacin > ciprofloxacin > gentamicin. All the MRSA
isolates had the capacity to form biofilms and produce enterotoxins, especially enterotoxin B as
only one isolate produced enterotoxin C. The presence of Penicillin Binding Protein 2a was
detected in the isolates tested in this study. The leaf extracts of B. coriacea contain the
following: terpenes, alkaloids phenols, steroids, cardiac glycosides, anthraquinone and was
found to possess antibacterial activity. Of the twenty (20) isolates of MRSA subjected to
molecular characterization, only one had mecA gene. The results showed that there is presence
of methicillin resistant S. aureus (MRSA) among healthy tertiary school students in Delta State
of Nigeria, which are capable of producing biofilms associated with bacteria resistance. It was
also observed that most of the MRSA isolates are multi-drug resistant which signifies antibiotic
therapy failure in this area. It is also obvious from the results that there is the possibility of
MRSA to possess penicillin binding protein 2a without mecA gene.
OLISELOKE, A (2021). Incidence, Molecular Characterization And Sensitivity To Buchholzia Coriacea Leaf Extract Of Methicillin Resistant Staphylococcus Aureus Nasal Isolates From Tertiary Institution Students In D. Afribary. Retrieved from https://tracking.afribary.com/works/incidence-molecular-characterization-and-sensitivity-to-buchholzia-coriacea-leaf-extract-of-methicillin-resistant-staphylococcus-aureus-nasal-isolates-from-tertiary-institution-students-in-de
OLISELOKE, ANIE "Incidence, Molecular Characterization And Sensitivity To Buchholzia Coriacea Leaf Extract Of Methicillin Resistant Staphylococcus Aureus Nasal Isolates From Tertiary Institution Students In D" Afribary. Afribary, 15 May. 2021, https://tracking.afribary.com/works/incidence-molecular-characterization-and-sensitivity-to-buchholzia-coriacea-leaf-extract-of-methicillin-resistant-staphylococcus-aureus-nasal-isolates-from-tertiary-institution-students-in-de. Accessed 09 Nov. 2024.
OLISELOKE, ANIE . "Incidence, Molecular Characterization And Sensitivity To Buchholzia Coriacea Leaf Extract Of Methicillin Resistant Staphylococcus Aureus Nasal Isolates From Tertiary Institution Students In D". Afribary, Afribary, 15 May. 2021. Web. 09 Nov. 2024. < https://tracking.afribary.com/works/incidence-molecular-characterization-and-sensitivity-to-buchholzia-coriacea-leaf-extract-of-methicillin-resistant-staphylococcus-aureus-nasal-isolates-from-tertiary-institution-students-in-de >.
OLISELOKE, ANIE . "Incidence, Molecular Characterization And Sensitivity To Buchholzia Coriacea Leaf Extract Of Methicillin Resistant Staphylococcus Aureus Nasal Isolates From Tertiary Institution Students In D" Afribary (2021). Accessed November 09, 2024. https://tracking.afribary.com/works/incidence-molecular-characterization-and-sensitivity-to-buchholzia-coriacea-leaf-extract-of-methicillin-resistant-staphylococcus-aureus-nasal-isolates-from-tertiary-institution-students-in-de