scholarly journals Synergistic effect of Zinc Oxide nanoparticles and Vancomycin on Methicillin resistant Staphylococcus aureus

2020 ◽  
Vol 1 (3) ◽  
pp. 93-98
Author(s):  
Reyam Thamer ◽  
Essra Alsammak

The study was carried out on (120) various clinical samples collected from patients attended Al Salam and Al-Khansa Hospitals and the Public Health Laboratory in the Mosul city during the of 4 months (September - December 2019). Samples were cultured on Mannitol Salt Agar medium, 105 samples give a positive result (grew the bacteria). 50 isolates were fermented mannitol sugar, at a rate of 47.6%, depending on the phenotypic characteristics and production of Coagulase, 14 isolates were identified, at a rate of 13.3%, belonging to Staphylococcus aureus the diagnosis were confirmed using VITEK system. The highest isolation rate from wounds was 57%, then abscesses 21%, blood samples 14%, and urinary tract infections 7%. The sensitivity of the isolates was tested for 16 antibiotics, the isolates showed variation in their resistance to antibiotics. Most of the isolates showed high resistance at 92.8% to each of Oxacillin, Vancomycin, which were diagnosed as MRSA and VRSA. Vancomycin MICs against MRSA and VRSA ranged (2500-5000) g /mL. MIC for nanoparticles sized (30, 20, 50-150) nm ranged (5000-10000) g / mL for isolates that are positive coagulase. In this study the efficacy of vancomycin was improved in combination with ZnO nanoparticles. results showed a decrease in vancomycin MICs from (2500-5000) g / mL to (39-78.125) g \ mL when mixed with ZnO 20 nm.

2013 ◽  
Vol 141 (5-6) ◽  
pp. 349-353 ◽  
Author(s):  
Ivana Cirkovic ◽  
Slobodanka Djukic ◽  
Dragana Vukovic ◽  
Goran Stevanovic ◽  
Milena Svabic-Vlahovic ◽  
...  

Introduction Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) present the growing problem in the whole world. Carriage of MRSA is most frequent in the nose, and medical students come in contact both with patients and different persons in the community. Therefore, they may be significant for the transmission of MRSA from hospitals to out- of-hospital communities and vice versa. Objective. The aim of this study was to establish the carriage rate among students of the second, third and fourth year of study at the School of Medicine in Belgrade and to analyze their genotypic and phenotypic characteristics. Methods. In total 533 nasal samples were taken. The samples were incubated in Trypcase-soy broth supplemented with 6.5% NaCl, and thereafter the swabs were inoculated on mannitol salt agar supplemented with 2 ?g/mL of oxacillin. The presence of nuc, mecA and Panton-Valentine leukocidin genes was examined by PCR. The characteristics of the MRSA strains were determined using: antibiotic susceptibility testing by Vitek2 System, SCCmec, agr typing and MLST. Results. MRSA was isolated from two of 533 investigated samples (0.37%). MRSA were isolated from the students of the second and third year of study. Profiles of strains were: ST80 (SCCmec type IV, agr type 3) and ST152 (SCCmec type V, agr type 1). MRSA strains were multiresistant. Conclusion. The nasal carriage rate of MRSA in population of medical students of the first year of study in Belgrade is low. Genotypic and phenotypic characteristics of MRSA strains indicate their community origin. MLST typing revealed that isolates belong to ST80 and ST152.


2017 ◽  
Vol 2 (1) ◽  
pp. 29 ◽  
Author(s):  
Zaini Mohd Zain ◽  
Muhammad Fikri Johari ◽  
Nurul Shahirah Mohd Husin ◽  
Nurul Syamimi Rozman ◽  
Athirah Ab Rashid ◽  
...  

Introduction: To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage and detection of S. aureus leukotoxins among medical students of Universiti Teknologi MARA. Methods: Both sides of the anterior nares of 136 volunteers, comprising 68 preclinical and 68 clinical medical students, were swabbed and immediately cultured onto mannitol salt agar for growth of S. aureus. Standard microbiological techniques were conducted to identify and confirm the S. aureus colonies and susceptibility test against oxacillin were conducted by using Kirby-Bauer method to determine their resistance to methicillin. Polymerase chain reaction was performed for detection of leukotoxins, i.e., Panton-Valentine Leukocidin (PVL) and -haemolysin genes. Results: Nineteen students (14%) consisting of 10 preclinical (14.7%) and 9 clinical (13.2%) were nasal carriers of S. aureus. However, none of the S. aureus isolates were MRSA. No PVL gene was detected but eight of them were positive for -haemolysin gene. Conclusion: There were no MRSA nasal carriers among the medical students, but a low prevalence of S. aureus nasal carriers was detected. These carriers do not pose as high risk because none of the strains of S. aureus possess both the -haemolysin toxin and the PVL toxin that are associated with tissue necrosis.


2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  

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.


2019 ◽  
Vol 6 ◽  
pp. 59-62
Author(s):  
Ranjana K.C. ◽  
Ganga Timilsina ◽  
Anjana Singh ◽  
Supriya Sharma

Objectives: To isolate methicillin resistant Staphylococcus aureus (MRSA) from anterior nares of dairy workers and dairy products and assess the antibiotic susceptibility pattern of the isolates. Methods: Swab samples collected from anterior nares of dairy workers and dairy product (butter) were inoculated into mannitol salt agar and incubated at 37ºC for 24 hours. Identification was done based on colony characteristics, Gram's staining, catalase, oxidase and coagulase test. Antibiotic susceptibility testing was done by modified Kirby Bauer disc diffusion method. MRSA was confirmed by using cefoxitin disc. Results: A total of 109 S. aureus (98 from dairy workers and 11 from butter samples) were isolated. Out of them 32 MRSA were isolated from dairy workers and 4 from butter samples. The association between age group and MRSA was found insignificant (p = 0.115). The association of MRSA between male and female workers was found significant (>0.05). About 86% of the MRSA isolates were susceptible to Gentamicin (86.11%) followed by Ciprofloxacin (77.78%). Conclusion: Detection of MRSA among dairy workers and dairy products warrants proper handling and adequate control measures to prevent transmission of MRSA from dairy industry.


2009 ◽  
Vol 48 (175) ◽  
Author(s):  
Bidya Shrestha ◽  
B M Pokhrel ◽  
T M Mohapatra

Introduction: Methicillin resistant Staphylococcus aureus (MRSA), the most common cause ofnosocomial infection has been a major cause of morbidity and mortality around the world. They arenormally resistant to most of the antibiotics used in clinical practice. This study has been carried outto fi nd out the resistance pattern among S. aureus.Methods: During November 2007 to June 2008, clinical samples from patients with nosocomialinfection were processed for culture and sensitivity following standard methodology in microbiologylaboratory, Tribhuvan University teaching hospital, Kathmandu, Nepal.Results: Among 149 Staphylococcus aureus isolates, highest resistance was observed against Penicillin(91.94%) followed by Fluoroquinolone (61.74%), Erythromycin (52.94%), Gentamicin (46.98%),Cotrimoxazole (42.95%), Tetracycline (40.94%) and others, whereas susceptibility was observedmaximum against Chloramphenicol (94.85%) followed by Rifampicin (92.61%), Tetracycline(59.06%), Cotrimoxazole (57.04%), and others. None of the isolates were resistant to Vancomycinand Teicoplanin. Of these isolates 44.96 % of the isolates were Methicillin resistant S. aureus (MRSA).Resistance to Penicillin, Fluoroquinolone, Erythromycin, Gentamicin, Co-trimoxazole and Tetracyclinewere associated signifi cantly with MRSA isolates (X2= 8.779, p<0.05, X2= 74.233, p<0.05, X2= 84.2842,p<0.05, X2= 108.2032, p<0.05, X2= 88.1512, p<0.05 and X2= 79.1876, p<0.05 respectively). Althoughmost of the Methicillin sensitive S. aureus (MSSA) isolates were susceptible to both Rifampicinand Chloramphenicol, only Rifampicin susceptibility was signifi cantly associated with them (X2=10.1299, p<0.05). Among three Biochemical tests for the detection of β lactamase detection namelychromogenic, iodometric and acidimetric test, chromogenic test method had highest sensitivity andspecifi city.Conclusions: Since MRSA comprised a greater part of S. aureus isolates and were multi-resistant,patients infected by such strains should be identifi ed and kept in isolation for hospital infectioncontrol and treated with second line of drug like vancomycin.Key Words: β lactamase, methicillin resistant Staphylococcus aureus,methicillin sensitive Staphylococcus aureus, resistance pattern


Author(s):  
Rikhi Ram Marasini ◽  
Pratikshya Shrestha ◽  
Prabhat Dhakal ◽  
Sukra Raj Shrestha ◽  
Sirjana Adhikari ◽  
...  

The main objective of this study was to determine the prevalence of Methicillin Resistant Staphylococcus aureus (MRSA) in paper currency. The paper currencies in circulation in Pokhara Metropolitan City were inspected. Bills of various denominations (Rs 5, 10, 20, 50, 100, 500 and 1000) were collected from five different locations; namely Food and Vegetable Shop, Bus conductor, Hospital Pharmacy, Butcher Shop and Grocery Shop. Collected sample were cultured and incubated for 24 hours at 37 oC in Brain Heart Infusion (BHI) Broth. The inoculums were further cultured on Mannitol Salt Agar (MSA) and Blood Agar (BA) media to obtain colonies, which were examined and evaluated for various parameters like gram staining and biochemical tests for identification. Then, antibiotic susceptibility test of the isolates was performed using standard procedures. A total of 35 sample of paper currency were processed, all of which showed positive growth. Out of 86 total isolates, 21 (24.42%) were Staphylococcus aureus followed by Coagulase Negative Staphylococci 19 (22.09%), Diptheroids 14 (16.3%), Bacillus spp 13 (15.11%), Micrococci 9 (10.46%), Streptococcus pneumonia 4 (4.65%), Viridans Streptococcus 4 (4.65%) and Streptococcus pyogenes 2 (2.32%). The total prevalence of MRSA in this study was 7 (33.33%). Paper currency contaminated with MRSA poses a high threat to those handling the bills as well as the community. Thus, this study suggests proper hygiene measures to be adopted after handling of paper currency to minimize the risk of contamination and emergence of diseases.


2019 ◽  
Author(s):  
Raja Ram Gurung ◽  
Prashanna Maharjan ◽  
Ganga GC

Abstract Background: Staphylococcus aureus is one of the important superbugs distributed throughout the world. It causes minor skin infections to severe complications including nosocomial infections in both hospitals and community settings. These strains have multi-drug resistant property. Hence, they are difficult to manage which increase health-related costs and simultaneously intensifying the need for new antibiotics. The extent of Methicillin-Resistant Staphylococcus aureus (MRSA) in children is largely unknown. The study determines the current status of S. aureus and MRSA causing various infections in pediatric patients visiting International Friendship Children’s Hospital (IFCH). Methods: A cross-sectional study was conducted among patients visiting a hospital. Various clinical specimens were aseptically collected and processed according to standard microbiological procedures. Isolation and identification of S. aureus were done by microscopy, mannitol fermentation, and coagulase positivity. All identified S. aureus isolates subjected to in-vitro antibiogram by Kirby-Bauer disc diffusion technique adopting Clinical and Laboratory Standards Institute (CLSI) guideline. Isolates resistant to cefoxitin were considered to be MRSA. Whereas, isolates produced D-shaped inhibition zone around clindamycin when kept near erythromycin were considered to be Inducible Clindamycin Resistant (ICR). Results: 672 various types of clinical samples were processed from the microbiology laboratory from June and November 2015. Out of 300 culture positive samples, 52 (17.3%) were S. aureus isolates, among them 39 (75.0%) were found to be MRSA. The D-test showed that Macrolide-Lincosamide-Streptogramin-B (MLSB) phenotype was 15.4%. Conclusion: The study shows the MRSA occurrence is prevalent in pediatric patients and newer classes’ drugs are found more effective than β-lactam drugs to treat S. aureus infection. However, restriction on the indiscriminate use of such drugs may be an effective strategy to control the drug resistance. Keywords: Methicillin-Resistant Staphylococcus aureus (MRSA), Macrolide-Lincosamide-Streptogramin B (MLSB) phenotype, Inducible Clindamycin Resistant (ICR) test or D-zone test, Antibiotic resistance, Nepal


2013 ◽  
Vol 51 (3) ◽  
pp. 1026-1027 ◽  
Author(s):  
J. Veenemans ◽  
C. Verhulst ◽  
R. Punselie ◽  
P. H. J. van Keulen ◽  
J. A. J. W. Kluytmans

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