Phage typing, PCR amplification for mecA gene, and antibiotic resistance patterns as epidemiologic markers in nosocomial outbreaks of methicillin resistant Staphylococcus aureus

AbstractMethicillin-resistantStaphylococcus aureus(MRSA) has been notifiable in Western Australia since 1985. This article reviews the notification data from 1994 to 1997, focusing on increases in MRSA notifications and the proportion that are local strains; changes in the geographical distribution of MRSA; and changes in antibiotic-resistance patterns.

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Mutation-Based Antibiotic Resistance Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

Pharmaceuticals ◽

10.3390/ph14050420 ◽

2021 ◽

Vol 14 (5) ◽

pp. 420

Author(s):

Tanveer Ali ◽

Abdul Basit ◽

Asad Mustafa Karim ◽

Jung-Hun Lee ◽

Jeong-Ho Jeon ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Active Site ◽

Methicillin Resistant Staphylococcus Aureus ◽

Meca Gene ◽

Resistance Mechanism ◽

Ligand Docking ◽

Clinical Samples ◽

Allosteric Site ◽

Methicillin Resistant

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.

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Evaluation of antibiotic resistance pattern and mecA gene frequency in methicillin-resistant Staphylococcus aureus strains collected from clinical specimens in Marand hospital and treatment centers, Iran

Tabari Biomedical Student Research Journal ◽

10.18502/tbsrj.v2i4.5469 ◽

2021 ◽

Author(s):

Abolfazl Jafari-Sales ◽

Zahra Sadeghi Deylamdeh ◽

Afsoon Shariat

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Methicillin Resistant Staphylococcus Aureus ◽

Meca Gene ◽

Disk Diffusion ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Medical Centers ◽

Wide Range

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods. Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene. The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics. Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.

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Methicillin-Resistant Staphylococcus aureus ST80 Clone: A Systematic Review

Toxins ◽

10.3390/toxins12020119 ◽

2020 ◽

Vol 12 (2) ◽

pp. 119 ◽

Cited By ~ 3

Author(s):

Assia Mairi ◽

Abdelaziz Touati ◽

Jean-Philippe Lavigne

Keyword(s):

Systematic Review ◽

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Methicillin Resistant Staphylococcus Aureus ◽

Sampling Period ◽

Spa Typing ◽

Methicillin Resistant ◽

Resistance Patterns ◽

Mrsa Strains ◽

Spa Type

This review assessed the molecular characterization of the methicillin-resistant Staphylococcus aureus (MRSA)-ST80 clone with an emphasis on its proportion of total MRSA strains isolated, PVL production, spa-typing, antibiotic resistance, and virulence. A systematic review of the literature was conducted on MRSA-ST80 clone published between 1 January 2000 and 31 August 2019. Citations were chosen for a review of the full text if we found evidence that MRSA-ST80 clone was reported in the study. For each isolate, the country of isolation, the sampling period, the source of isolation (the type of infection, nasal swabs, or extra-human), the total number of MRSA strains isolated, number of MRSA-ST80 strains, antibiotic resistance patterns, PVL production, virulence genes, and spa type were recorded. The data from 103 articles were abstracted into an Excel database. Analysis of the data showed that the overall proportion of MRSA-ST80 has been decreasing in many countries in recent years. The majority of MRSA-ST80 were PVL positive with spa-type t044. Only six reports of MRSA-ST80 in extra-human niches were found. This review summarizes the rise of MRSA-ST80 and the evidence that suggests that it could be in decline in many countries.

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