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Updated: Apr 8, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Antiseptic Resistance in Methicillin Sensitive and Methicillin Resistant Staphylococcus aureus Isolates from Some
Azar Hasanvand, Sobhan Ghafourian, Morovat Taherikalani
1Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam/ Iran, I.R. pakzad_i2006@yahoo.com.
Background:
Extensive use of antibiotics and biocide in treatment of patients and cleaning of surfaces and medical equipment has led to the emergence of resistant microorganisms. The current research goals to determine the antiseptics Minimum Inhibitory Concentration value in Staphylococcus aureus (methicillin -resistant Staphylococcus aureus and methicillin sensitive Staphylococcus aureus) isolates from some major hospitals in Iran and to detect qacA/B, norA , smr and blaZ genes.
Methods:
Two hundred isolates of S. aureus including 100 MRSA and 100 MSSA clinical isolates were collected from 4 hospitals in the west of Iran during period 2012 to 2013. Detection of disinfectant resistant genes (qac A/B, smr and norA), antimicrobial resistance genes (mecA and blaZ) and SCCmec typing of MRSA isolates was performed by PCR.
Results:
MIC of chlorhexidine digluconate (CHX) in 70% of MRSA and 30% of MSSA strains was 8-16 µg/ml. High level of MIC of citrimide (>2 µg/ml) in MRSA and MSSA isolates was 20% and 5% , respectively. MIC of benzalkonium chloride (BC) in 80% of MRSA and 83% of MSSA isolates was less than 2 µg/ml; only 9% of MRSA had MIC higher than 2 µg/ml. Frequency of antiseptic and antibiotic resistance genes norA, blaZ and qacA/B in MRSA isolates were 83%, 98% and 9%, respectively; while this value for MSSA isolates were 62%, 8% and 0%, respectively. The smr gene was not detected in both MRSA and MSSA isolates. In all biocides high MIC were observed in SCCmec type III and IVc. High frequency of qacA/B gene was found in SCCmec type III,Vc and IVb, which were 66.6% ,22% and 11.1% respectively.
Conclusion:
We found SCCmec types III, Vc was related to high MIC of biocide in MRSA isolates.
Insights
Antimicrobial resistance is rising due to widespread biocide and antibiotic use. This study found specific Staphylococcus aureus strains, particularly MRSA, exhibit high biocide resistance linked to certain genetic factors.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Biology
Background:
- Extensive use of antibiotics and biocides has driven the emergence of resistant microorganisms.
- Understanding antiseptic resistance mechanisms in Staphylococcus aureus is crucial for infection control.
Purpose of the Study:
- To determine the Minimum Inhibitory Concentration (MIC) of antiseptics against Staphylococcus aureus (MRSA and MSSA) isolates.
- To identify the prevalence of specific antiseptic and antibiotic resistance genes (qacA/B, norA, smr, blaZ) in these isolates.
Main Methods:
- Collected 200 S. aureus isolates (100 MRSA, 100 MSSA) from Iranian hospitals (2012-2013).
- Utilized Polymerase Chain Reaction (PCR) to detect disinfectant resistance genes (qacA/B, smr, norA), antimicrobial resistance genes (mecA, blaZ), and performed SCCmec typing.
Main Results:
- High MIC values for chlorhexidine digluconate and citrimide were observed in MRSA and MSSA strains.
- Prevalence of resistance genes varied: norA (83% MRSA, 62% MSSA), blaZ (98% MRSA, 8% MSSA), qacA/B (9% MRSA, 0% MSSA).
- SCCmec types III and IVc were associated with high biocide MICs, and qacA/B gene frequency was high in SCCmec types III, Vc, and IVb.
Conclusions:
- SCCmec types III and Vc are linked to elevated biocide MICs in MRSA isolates.
- Genetic profiling of S. aureus is essential for understanding and combating antimicrobial and antiseptic resistance.
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