Available via license: CC BY 4.0
Content may be subject to copyright.
Original research
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
Studying the resistance of methicillin –resistant staphylococcus aureus against
Different groups of antibiotics
Huda S. Alagely1 Eman N. Ismail1 Tagreed A. Kreem2 Abeer A. Baqer3
Ayad W. Alenawey4 Muhammad Iqbal5
Affiliation: 1Biotechnology Research Center / Al Nahrain University
2Medical and Pharmacentical Sciences / AIbn Sina University
3Dijlah University College / Iraq
4Babylon Agriculture Directorate
5Government College University / Faisalabad / Pakistan
* Correspondence: huda_alagely@yahoo.com
Abstract:
Back ground: MRSA developed resistance to β-lactam antibiotics through the acquisition of
the mecA gene that encodes penicillin-binding protein 2a (PBP2a), which has a significantly
reduced affinity for β-lactam antibiotics, thereby conferring β- lactam resistance . The detection
of mecA by the (PCR) is considered a gold-standard technique for methicillin resistance
detection .
Objective: This study was aimed to isolation and identification of S.aureus by traditional and
molecular methods and determine their susceptibility to different groups of antibiotics.
Materials and Methods: Two hundred and ten samples were collected from different sources
of patients in different age groups and for the period from the beginning of January 2015 until
the end of June 2015, from different Hospitals in Baghdad (Ibn Albalady, Al Yarmouk,
Baghdad teaching hospital and AlKindy).
Results: Depending on the molecular methods (137) out of (210) isolates was methicillin –
resistant Staphylococcus aureus MRSA. Antibiotic sensitivity test was conducted using 20
types of antibiotics include:- Amikacin, Amoxicillin, Ampicillin, Azithromycin, Cefoxitin,
Ciprofloxacin, Clarerythromycin, Clindamycin, Chloramphenicol, Erythromycin, Gentamycin,
Methicillin, Norfloxacin, Oxacillin, Penicillin, Rifampin, Teicoplanin, Tetracycline,
Tobramycin and Vancomycin.
Conclusion: The results showed that the highest resistance was among beta-lactam group,
where the ratio was 100% resistance to Ampicillin and Penicillin, and ratio of 91% to 86.66%
and 86.66% resistance to Methicillin, Oxacillin and Amoxicillin respectively.
The lowest resistance was among a group of antagonists Aminoglycosides resistance and
ratios was 37.77%, 31.11% and 35.55% to Amikacin, Tobramycin and Gentamycin,
respectively, while the rest have different kinds of antibiotics effects.
Key words: Staphylococcus aureus, Antibiotics sensitivity, MRSA.
Publisher’s Note:
JOBRC stays neutral
with regard to
jurisdictional claims
in published maps
and institutional
affiliations.
Copyright: © 2022
by the authors.
Submitted for
possible open access
publication under the
terms and conditions
of the Creative
Commons Attribution
(CC BY) license
Received: 25/5/2022
Accepted: 15/8/2022
Published: 5/12/2022
70
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
Introduction
Methicillin-resistant Staphylococcus aureus (MRSA) is a major infection prevention and control challenge
globally. S. aureus is among the most important and commonly isolated human bacterial pathogens commonly
known for causing mild to severe skin infections resulting in death if not treated promptly (1). Since its first
appearance, methicillin resistance in S. aureus strains has become widespread in hospitals and intensive care
units (ICUs).Methicillin resistance is almost exclusively caused by the production of an additional penicillin
binding protein (PBP2a) encoded by the mecA gene, although other mechanisms have been described (2).Many
drugs and antibiotics are become useless for MRSA and new antibiotics begins to use now a day .
Material and Methods
1- Clinical Isolates Two hundred and ten clinical samples collected from three hospitals Al-kindy, Al-Yarmouk
and Ibn Al-balady hospitals. From the beginning of January 2015 till the end of May 2015
- Isolation and identification of S. aureus by traditional methods -Culturing on selective media Direct smear
examination by Gram’s stain followed by culture on Mannitol salt agar at 37°C overnight incubation. The
isolates were identified by characteristic colony morphology of Staphylococcus. Yellow-colored colonies were
obtained on Mannitol salt agar, further confirmed by biochemical reactions using API Staph.,
3- Molecular identification of S. aureus -Bacterial Genomic DNA Extraction: - an overnight culture in brain
heart infusion broth was collected by and Extraction of DNA from isolated bacteria, carried out by using
genomic centrifugation DNA kit (Gene aid). The DNA was preserved with 50-100µl of TE solution in
Eppendorf tubes at -20Cº.
1- Detection of S. aureus nuc gene by polymerase chain reaction (PCR)
Specific primer PCR used for detection of the nuc gene for conformation the S. aureus, according to (3). These
primers synthesized by Cinna Gen Company Table (1).
Table (1): The sequence and concentration of forward and reverse primers of nuc gene.
Primers Type
Primers Sequence
Concentration
in Pico moles
Product
size
nuc geneForward
5-GCGATTGATGGTGATACGGTT--3
30262.27
300bp
nuc gene Reverse
5-AGCCAAGCCTTGACGAACTAAAGC-3
35265.50
300bp
PCR reaction was conducted in master mix tube with 20µl of reaction mixture containing, 1 µl of each primer, 5
µl DNA template and 13 µl of deionized water (Table 2)
Table (2): The mixture of conventional PCR working solution for detection of, nuc gene in S. aureus
Working solution
µl
Water
Forward primer
Reverse primer
DNA
13µl
1µl
1µl
5µl
Final volume
20 µl
Amplification was conducted using a master cycler Eppendorf programmed with 35 cycler for Initial
denaturation 95°C for 3 min., Denaturation for 94°C 1min., Annealing 55°C 30 sec., Extension 72°C 1.5min and
final Extension 72°C 3.5min. (Table 3).
71
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
Table (3): PCR program for nuc gene amplification by the conventional methods.
Thermocycler conditions
Temperature (°C)
Time (min)
Initial denaturation
Denaturation
Primmer annealing
Primmer extension
Final extension
94 °C
94 °C
55 °C
72 °C
72 °C
3min
1min
30sec.
1.5min.
3.5min
Cycles number : 35 cycle
2-Detection of mec A gene in S. aureus by specific primer:-
PCR used for detection of the MecA gene for conformation the identification of the S. aureusaccording to (4).
These primers synthesized by Cinna Gen Company Table (4).
Table (4): The sequence and concentration of forward and reverse primers of mecA gene.
Primers Type
Primers Sequence
Product size
mecA Forward
5-AACAGGTGAATTATTAGCACTTGTAAG-3
170 bp
mecA Reverse
5-ATTGCTGTTAATATTTTTTGAGTTGAA-3
170 bp
PCR reaction was conducted in 20µl of reaction mixture containing, 1 µl of each primer, 5 µl DNA template
and 13 µl of deionized water (Table 5).
Table (5): The mixture of conventional PCR working solution for detection of, mecA gene in S. aureus.
Contained
µl
Water
Forward primer
Reverse primer
DNA
13 µl
1 µl
1 µl
5 µl
Final volume
20 µl
Amplification was conducted using a master cycler Eppendorf programmed with 35 cycler for Initial
denaturation 95°C for 4 min., Denaturation for 94°C 30sec., Annealing 55°C 1min., Extension 72°C 1min and
final Extension 72°C 5min. (Table 6)
Table (6): PCR program for MecA gene amplification by the conventional methods
Thermocycler conditions
Temperature (°C)
Time (min)
Initial denaturation
Denaturation
Primmer annealing
Primmer extension
Final extension
94°C
94°C
55°C
72°C
72°C
4min.
30sec.
1min.
1min
5min.
72
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
3- Antibiotic susceptibility test was performed by the modified Kirby-Bauer method to twenty different
antibiotics. Antimicrobial Susceptibility testing by disk diffusion Method was performed by the modified Kirby-
Bauer method(5), Mueller-Hinton Plates Mueller-Hinton agar was prepared according to the manufacturer’s
instructions, and then the medium was cooled to 45-50 °C and poured into the plates, allowed to set on a level
surface to a depth of approximately 4mm. When the agar was solidified, the plates were stored at 4 °C until use
And the inoculate colonies from overnight culture of staphylococcal isolates were transferred to 5 ml tube of
normal saline to obtain culture with 1.5×10 CFU/ml by adjusting to 0.5 McFarland standard
The plates were inoculated by dipping a sterile swab into the inoculate; care must be taken to express excess
broth from the swab prior to inoculation, by pressing and rotating the swab firmly against the side of the tube
above the level of the fluid. The swab was rubbed over the surface of the medium three times rotating the plate
through at an angle of 60 after each application. Finally the swab was passed around the edge of agar surface.
The inoculate were left for a few minutes to dry at room temperature with the lid being closed. By using a
sterile forceps, antibiotic discs were placed on the inoculated plate. Discs should be warmed to room
temperature, and then dispensed on the agar surface; they should gently pressed down with sterile
forcepsReading the Results After incubation, the diameters of the complete zone of inhibition were noted and
measured in millimeters. The diameter of inhibition zone for individual antimicrobial agent was translated in
terms of sensitive, intermediate and resistant categories by comparison with the standard inhibition zone (Table
7)
Table (7): Antibiotics and their Zone diameter interpretation standards (6)
Id
Antimicrobial agent
Disc potency
(μg /Disc)
Resistant
Intermediate
Sensitive
1
Amikacin
30
≤ 14
15-16
≥17
2
Amoxicillin
25
≤19
-
≥20
3
Ampicillin
10
≤28
-
≥29
4
Azithromycin
15
≤13
14-17
≥18
5
Cefoxitin
30
≤14
15-17
≥18
6
Ciprofloxacin
10
≤10
11-15
≥16
7
Clarerythromycin
10
≤10
11-13
≥14
8
Clindamycin
10
≤14
15-20
≥21
9
Chloramphenicol
30
≤12
13-17
≥18
10
Erythromycin
15
≤13
14-22
≥23
11
Gentamycin
10
≤10
11-13
≥14
12
Methicillin
10
≤19
10-13
≥16
13
Norfloxacin
10
≤12
13-16
≥17
14
Oxacillin
1
≤10
11-12
≥13
15
Penicillin G
10
≤ 28
-
≥ 29
16
Rifampin
15
≤16
17-19
≥20
17
Teicoplanin
30
≤10
11-13
≥14
18
Tetracycline
10
≤ 14
15-18
≥ 19
19
Tobramycin
10
≤12
13-14
≥16
20
Vancomycin
30
-
-
≥15
73
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
Results
Clinical Samples -Identification of S. aureus by traditional methods a total number of 210 clinical samples
were collected from different three hospitals in Baghdad city Al-kindy, Al-Yarmouk and Ibn Al-balady
hospitals. The specimens included nasal swab, wound swab, burn swab, abscess and pus, sputum, ear swab,
urine and blood culture. (150) isolates identified as Staphylococci on a mannitol salt agar depending on yellow
color of the colonies, themedia considered a selective and differential growth medium which is used for
encouraging the growth of Staphylococci and inhibit others by containing high concentration of NaCl and
phenol red as an indicator figure(1) (7).150 isolates gave a positive result and were identified as S. aureus due to
the production of catalase enzyme which is distinguished them from Streptococcus spp. (5; 8). Finally, the API
Staph. System was used for accurate identification of the isolates at generic and species level. The test was
applied on all isolates, which previously identified by conventional biochemical tests the results gained from
API Staph system figure(2).
Figure (1): Colonies of S. aureus growth on mannitol salt agar in 37 °C for 24 h.
Figure (2): API Staph system for S. aureus
Identification by Molecular methods
All isolates were submitted to conventional PCR for further identification on molecular level by using specific
primers for detection nuc gene, from (150) S. aureus isolates recognizing depending on traditional methods
(143) isolates were positive for nuc gene with product size 300pb figure The nuc primer set recognized all
tested isolates belonged to S. aureus, but not other bacteria tested Published data indicate that treatment with
antibiotics does not interfere with the detection of the nuc gene as long as minimum quantities of the target
DNA sequences are still present in the clinical specimens
Figure (3): Agarose gel electrophoresis of PCR amplification products of S.aureus, nuc gene (2% agarose, TBE buffer (1X), 5V/Cm,
2hr.). M: The DNA molecular Wight marker (100 bp ladder); Lanes (2-9) positive amplification of 300 bp for nuc gene
74
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
The isolates that were previously identified by morphological, biochemical characteristics and molecular level
by nuc gene primers as S. aureus were tested for antibiotic susceptibility using Methicillin antibiotic discs
(5μg/disc) by applying the antibiotic disc diffusion methodThe results of this study confirmed that out of (143)
tested S. aureus isolates that were (137) isolated exhibited a high level of resistance to Methicillin, the target
antibiotic, which is reflected MRSA. This result is agreed with the outcome obtained by (9) in Saudi Arabia
Rapid and accurate detection of methicillin resistance in S. aureus is essential for the use of appropriate
antimicrobial therapy and for the control of nosocomial spread of MRSA strains. Thus evaluation the efficiency
of the disk diffusion method is important. All the positive isolates (137) that were characterized as MRSA by the
(methicillin disc test) were subjected to PCR to detect the presence of mecA gene, all of them gave positive
results with 170pb PCR product figure(4). The acquisition of mecA gene is considered to be the first genetic
requisite for methicillin resistance in Staphylococci (10 , 11 ,12).
Figure (4):- Agarose gel electrophoresis of PCR amplification products of S.aureus, mecA gene (2% agarose, TBE
buffer (1X), 5V/Cm, 2hr.). M: The DNA molecular Wight marker (100 bp ladder); Lanes (2-11) positive amplification
of 170 bp for mecA gene.
Antibiotic Sensitivity Profile of the MRSA isolates
Susceptibility of S. aureus isolates was detected against 20 types of antibiotics, which are differ in their action
(figure 5), table (8).
Figure (5):- Susceptibility of MRSA S. aureus isolates to 20 different antibiotics
75
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
Table (8): Susceptibility of MRSA S. aureus isolates to 20 different antibiotics
Amikacin AK , amoxicillin AX , ampicillin AM , azithromycin AZM , cefoxitin FOX , ciprofloxacin CIP ,
clarerythromycin CLR , clindamycin DA , clorophenicol CL , erythromycin E , Methicillin ME , Norfloxacin
NOR , Oxacillin OX , Penicillin GP , Rifampin RA , Teicoplanin TEC , Tetracycline TE , Tobromycine TOB ,
Vancomycine VA , Gentamycin CN.
Discussion
The results demonstrated that out of 137 tested S. aureus isolates (MRSA), 125 isolate (91.11%) were resistant
to methicillin while the rest (12 isolate) (8.88%) were intermediate .The disc diffusion method currently
recommended by the Clinical Laboratory Standard Institute (CLSI) in (2011) for phenotypic detection of
methicillin resistance in all staphylococci (methicillin is a narrow-spectrum β-lactam antibiotic of the penicillin
class). Like other beta-lactam antibiotics, methicillin acts by inhibiting the synthesis of bacterial cell walls .It
inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the
cell wall of Gram-positive bacteria (13). Also the results of this study showed that 119 (86.66%) isolates were
resistant to oxacillin (ORSA) table(9), 3(2.22%) were intermediate and 15 isolates (11.11%) were sensitive.
Oxacillin has been the agent recommended by the CLSI for phenotypic tests to predict resistance to
penicillinase-stable penicillin's (PSPs) due to its stability and superior sensitivity over other PSPs susceptibility
tests. The majority of ORSA isolates were found to be resistant to all β-lactam antibiotics used (14).
Furthermore, 100% of the isolates showed resistant to penicillin which is close to the percentage obtained by
the oxacillin as the two antibiotics belonged to the same class of antibiotic that kill the bacteria by the inhibition
of the cell wall synthesis. This may be due to the irrational use of this antibiotic. Such results are in agreement
Antibiotics
Resistance
Intermediate
Sensitive
NO.
%
NO.
%
NO.
%
AK
52
37.77
9
6.66
76
55.55
Am
137
100
0
0
0
0
AX
119
86.66
0
0
18
13.33
Azm
46
33.33
12
8.88
79
57.77
cip
101
73.33
15
11.11
21
15.55
CL
116
84.44
21
15.55
0
0
CLR
89
64.96
18
13.33
30
21.89
CN
49
35.55
39
28.88
49
35.55
DA
79
57.77
21
15.55
37
26.66
E
98
71.11
30
22.72
9
6.66
FOX
103
75.18
23
16.78
11
8.02
ME
125
91.11
12
8.88
0
0
NOR
67
48.88
27
19.7
43
31.38
OX
119
86.66
3
2.22
15
11.11
P
137
100
0
0
0
0
RA
88
64.44
3
2.22
46
33.33
TE
137
100
0
0
0
0
Tec
58
42.22
15
11.11
64
46.66
TOB
43
31.11
3
2.22
91
66.66
VA
61
44.52
15
10.94
61
44.52
76
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
with the study of(15) who reported that 100% resistance to penicillin and oxacillin by S. aureus isolates from
clinical hospitals in Cairo and to those results obtained in Saudi Arabia by(16). They partially agreed with the
data published by Khan et al. (2007) who recorded that 40% are resistance to the penicillin among their tested
isolates. On the other hand, vancomycin used in this study and it was found that Out of 137 MRSA isolates 61
(44.52%) isolates were resistant to vancomycin and of the same percentage were sensitive to itA maximum
percentage of resistance 100% was observed by the MRSA S. aureus isolates against, Ampicillin, Tetracycline,
Penicillin; 91.11% for Methicillin, 86.66% for Oxacillin and 86.66% for Amoxicillin. This may be due to their
belonging to the same group (β-lactam group) and to their similarity in action on the cell. They act by inhibiting
the synthesis of the peptidoglycan layer of bacterial cell walls. The peptidoglycan layer is important for cell wall
structural integrity.
The highest level of MRSA S. aureus sensitivity to aminoglycosides representing by tobramycin (66.66%);
amikacin (55.55%) and gentamycin (35.55%) antibiotics were found .Their resistance percentage agrees with
the results obtained by (17) indicated that despite aminoglycosides resistance among clinical MRSA isolates,
they are widespread but gentamycin remains active against most MRSA strains. The isolates were resistant to
Ciprofloxacillin in a percentage of 73.33%, and 48.88% to norflaxacin from the fluoroquinolone used. First and
second generation fluoroquinolones selectively inhibit the topoisomerase II ligase domain, leaving the two
nuclease domains intact. This modification, coupled with the constant action of the topoisomerase II in the
bacterial cell, leads to DNA fragmentation via the nucleases activity of the intact enzyme domains. Among the
aminoglycoside antibiotics used, erythromycins that act by inhibition of protein synthesis showed activity
against the tested MRSA isolates in such a way that 71.11% were resistance and 6.66% of them were sensitive.
For tetracycline, the percentage of the resistance was 100% , which was not agree with that of(18) who recorded
resistance of 24% among S. aureus strains isolated from hospitalized patients. While the percentage of
resistance to teicoplanin antibiotic was 42.22% and the percentage of sensitive isolates was 46.66%.
77
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
References
1-Rybak M, Laplante K.. Community-Associated Methicillin-Resistant Staphylococcus aureus: A Review.
Pharmacotherapy .(2005); 25(1): 74-85.
2- Harris L, Foster S, Richards R .An introduction to Staphylococcus aureus, and techniques for identifying
and quantifying Staphylococcus aureus adhesins in relation to adhesion to biomaterials: review. European Cells
and Materials.(2002); 4: 39-60.
3-Brakstad OG, Aasbakk K, maelandn JA..Detection of Staphylococcus aureus by polymerase chain reaction
amplification of thenuc gene .J. Clin. Microbial, (1992); 30(7): 1654–1660.
4- Martineau F, Picard FJ, Gernier L, Roy PH, Ouellette M, Trail E, Bergeron MG.. Multiplex PCR assay
for detection of clinically relevantantibiotic resistance genes on staphylococci isolated from patients infected
after cardiac surgery. J. Antimic Chemo, (2000); 46(4): 527-534.
5-Benson JH.. Microbiological Applications: Laboratory Manual in General Microbiology. 8th ed. McGraw-
Hill Higher Education. New York. (2001).
6-Clinical Laboratory Standard Institute. MMWR Morb. Mortal. Wkly. Rep. (2011); 51(26): 565-567.
7- Leboffe MJ, Pierce BE.. Microbiology: Laboratory Theory and Application. 3d ed. Morton Publishing
Company. Englewood, CO. (2010).
8- Brooks GF, Carroll KC, Butel JS, Morse SA.. (Jawetz) Melnick and Adelbergs Medical Microbiology,
24th. ed. The McGraw-Hill Companies, Inc., New York, (2007): 224-232
9- ALRuaily MA, Khalil OM.. Detection of (mecA) gene in methicillin resistant Staphylococcus aureus
(MRSA) at Prince A/Rhman Sidery Hospital, Al-Jouf, Saudi Arabia. J. Medi. Gene. Geno. (2011); 3(3): 4l-45.
10-Nobumichi K, Koki T, Shozo U..Analysis of diversity of mutations in the mecI gene and mecA
promoter/operator region of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.
Antimicrob Agents Chemother, (1998); 42(3): 717–720.
11- Lee EC.. Methicillin-resistant Staphylococcus aureus: The Deadly Superbug. The Journal of young
investigators, (2010): 1-9.
12-Anand KB, Agrawal P, Kumar S, Kapila K.. Comparison of cefoxitin disc diffusion test, oxacillin screen
agar and PCR for mecA gene for detection of MRSA .Indian Journal of Medical Microbiology; (2009); 27(1):
27-29.
13-Naimi TS, LeDell KH, Como-Sabetti K, Borchardt SM, Boxrud DJ, Etienne J, et al. Comparison of
community- and health careassociated methicillin-resistant Staphylococcus aureus infection. JAMA. .( 2013);
290: 2976–2984.
14-Naji SA, Abbas AF, AL-Hushemi EH.. Antibacterial activities of black tea alcohol ethanolic extract and
some antibiotics,(2009).
15- Rushdy AA, Salama MS, othman A. Detection of methicillin oxacillin resistant Staphylococcus aureus
isolated from some clinical hospitals in Cairo using mecA nuc genes and antibiotic susceptibility profile. Int. J.
Agri. Biol. (2007); 9(6): 800-806.
16-Sulaiman A. AL Yousef, Sabry Y. Mahmoud , Eihab M. Taha,. Prevalence of MRSA In Saudi Arabia:
Systemic Review and Meta-Analysis. African Jornal of Clinical Experemental Microbiology (2013); 14(3): 146-
154.
17-Jacqueline, Ca Asseray N, Batare E, Mabecque V, Kergueris MF, Dube L, Bugnon D, Potel G,
Callion J., In vivo efficacy of linezolide in combination with gentamycin for treatment of experimental
endocarditis due to methicillin-resistant Staphylococcus aureus. Int. J. Antimicrob. Agents. (2004); 24: 393-396.
18-Lobo-Sanchez AD, Lozano-zarain P, Martinez-Laguna Y, Gutiérrez-Cazarez Z, Rivera-Tapia A,
Torres' C, Rocha, Gracia RD.. Characterization of Staphylococcus spp strains isolated from hospital,
community and environmental in Puebla city, Mexico. A fri. J. Micro. Res. (2011); 5(16): 2266-2272. Khan,
A.U.; Sultan, A.; Tyagi, A.; Zahoor, S.
78
Huda et al., jobrc, vol 16, issue2, year2022
http://doi.org/10.24126/10.1234/jbrc.672
3rd International Virtual Conference of Biotechnology Research Center (IVCBRC-2022)
1
1
2
3
4
5
*Correspondence: huda_alagely@yahoo.com
MRSA β-lactam mecA a (PBP2a) β-lactam β- lactam. mecA
(PCR) .
.
.
Staphylococcus aureus MRSA
.
.
.
MRSA
79
