scholarly journals Methicillin-resistant Staphylococcus aureus colonization in HIV patients of Arba Minch province, Ethiopia: Carriage rates, antibiotic resistance, and biofilm formation

2019 ◽  
Vol 66 (4) ◽  
pp. 469-483 ◽  
Author(s):  
Aseer Manilal ◽  
Misgun Shewangizaw ◽  
Mohammedaman Mama ◽  
Tigist Gezmu ◽  
Behailu Merdekios
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Hiv Patients ◽  
Methicillin Resistant

scholarly journals Biofilm formation and antimicrobial resistance in methicillin-resistant Staphylococcus aureus isolated from burn patients, Iran

2014 ◽  
Vol 8 (12) ◽  
pp. 1511-1517 ◽  
Author(s):  
Solmaz Ohadian Moghadam ◽  
Mohammad Reza Pourmand ◽  
Farzaneh Aminharati
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Burn Patients ◽  
Burn Wound ◽  
Methicillin Resistant ◽  
Therapeutic Decisions

Introduction: Burns are the most serious forms of trauma and a major cause of mortality worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of burn wound infections; treatment has faced serious problems due to antibiotic resistance in these strains. Biofilm formation, which increases antibiotic resistance capabilities and is considered to be a virulence factor, also causes treatment failure and recurrent staphylococcal infections in burn patients. Methodology: A total of 135 pus/wound swabs were collected; S. aureus was identified by confirmatory tests. The icaA/D and mecA genes were detected in DNA extracts by polymerase chain reaction assay separately. To determine the prevalence of biofilm formation, a modified Congo red agar and the microtiter plate method were used. Investigation of antibiotic resistance was performed using the disk diffusion method. Results: S. aureus (48.87%) was identified in 65 (48.87%) samples, of which 40 (61.53%) were confirmed to be MRSA. Among MRSA and methicillin-sensitive S. aureus (MSSA) isolates, 97.5% and 60% produced biofilm, respectively. Resistance of MRSA isolates to amikacin, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, mupirocin, rifampin, tetracycline, and tobramycin was 64.1%, 76.92%, 51.28%, 87.18%, 71.8%, 10.26%, 5.13%, 89.74%, and 61.54%, respectively. All MRSA and MSSA isolates were susceptible to fusidic acid, linezolid, teicoplanin, tigecycline, and vancomycin. Conclusions: The high prevalence of biofilm-producing, drug-resistant S. aureus isolates in our study suggests that epidemiological studies on the characteristics of common strains found in burn centers and a definition of their antibiotic resistance pattern would be helpful for therapeutic decisions.

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

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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