Microbiology of MRSA: Structure, Virulence Factors, Antimicrobial Resistance, and Immunological Responses

This presentation provides an overview of MRSA, including its structure, virulence factors, antimicrobial resistance, and immunological responses. It also covers laboratory methods to discriminate between MRSA and sensitive staph, risk factors, and factors responsible for the development of genetically diverse MRSA.

MICROBILOGY OF
INFECTION RISK
MANAGEMENT
Name of the Student
Name of the University
Author note

Identify and describe the structure
of MRSA
•gram positive
•non motile spherical and facultative
anaerobes
•grows in clumps in most of the human skin
•forms golden pin gent color colonies
•showsβ-hemolysis ((Thapaliya et al.,
2018).
•coagulase positive
•, catalase positive(Thapaliya et al., 2018).
•developed through the horizontal gene
Figure : Staphylococcus
aureus
Source :(Thapaliya et al.,
2018).

virulence factors :
•protein A
•hyaluronidase.
•Microcapsule
•invasins,
•Coagulase
• staphylokinase
•toxins SE A-G
•Leucotoxins
•leucocidines, Figure : virulence factors
Source: (Parlet et al., 2016).

MECHANISM CAUSING THE ANTIMICROBIAL
RESISTANCE ASSOCIATED WITH MRSA
plasmid-encoded
penicillinase (Parlet et
al., 2016).
hydrolyzed the
betalactam of
penicillinase
Horizontal gene
transfer
Methicilline resisatnce
and comminity infection

immunological responses mediated
during infection in human host;
Figure : immunological response
Source : (Radic, 2018).

Laboratory method to discriminate
between Methicilline resistance staph
and sensitive staph
Cefoxitin and
oxacillin disc
Müeller-Hinton
agar (MHA) plates
containing 2%
NaCl
Discs were applied
and incubated at
35°C for 24h
Zone were
identified

factors responsible for development of genetically diverse
MRSA
According to Li et
al., (2016), , that
plasmid producing
blaZ β-lactamase
According to Li et
al., (2016), mecA
for producing
PBP 2a

Risk factors
•College students living in
dormitories
•intravenous drug users
(Radic, 2018)
•diabetes
•People that ingest
unpasteurized milk
•Users of quinolone antibiotics

References :
Li, M., Dai, Y., Zhu, Y., Fu, C. L., Tan, V. Y., Wang,
Y., ... & Qin, J. (2016). Virulence determinants
associated with the Asian community-
associated methicillin-resistant
Staphylococcus aureus lineage
ST59. Scientific reports, 6, 27899.
Parlet, C. P., Kavanaugh, J. S., Crosby, H. A.,
Cech, N. B., Oberlies, N. H., & Horswill, A. R.
(2016). Apicidin mediated attenuation of
MRSA virulence corresponds with quorum
sensing inhibition and enhanced immune
effector responses.

Radic, M. (2018). NETosis and ETosis: Incompletely
Understood Types of Granulocyte Death and
their Proposed Adaptive Benefits and
Costs. Apoptosis and Beyond: The Many Ways
Cells Die, 511-534.
Thapaliya, D., Kadariya, J., Capuano, M., Rush, H.,
Yee, C., Oet, M., ... & Smith, T. C. (2018).
Prevalence and Molecular Characterization of S.
aureus and MRSA on Children's
Playgrounds. The Pediatric infectious disease
journal.
Ueki, S., Tokunaga, T., Fujieda, S., Honda, K.,
Hirokawa, M., Spencer, L. A., & Weller, P. F.
(2016). Eosinophil ETosis and DNA traps: a new
look at eosinophilic inflammation. Current
allergy and asthma reports, 16(8), 54.

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