scholarly journals Anti MRSA and Antiviral Evaluation of Nano Silver Against Avian Influenza virus

2020 ◽  
Vol 1 (2) ◽  
pp. 59-66
Author(s):  
Muhammad Sannan Ahmad ◽  
Hira Musaddiq ◽  
Mirza Imran Shahzad

Preparation of nano sized silver particles was performed by using flower extract of Aerva javanica (AJ). Conversion of Ag+ ions to nanoscaled Ago was carried out in 90 min reaction by green approach. Antiviral potential of nanosilver (NS) was evaluated against Avian Influenza Virus (AIV) strain H9N2, in 9-11 days old chicken embryonated eggs. Synthesized particles were also screened against four methicillin-resistant Staphylococcus aureus (MRSA) strains by well diffusion method. Formation of spherical particles was confirmed by SPR band at 428 nm. XRD analysis confirmed face centred cubic crystal structure of particles with average particle size of 15 nm as calculated by Debye–Scherrer’s formula. Remarkable anti AIV activity was observed from NS particles with IC50 value 50 ?g/ml and this value is 200 times greater control drug i.e., Amantadine. Synthesized particles were also screened against four methicillin-resistant Staphylococcus aureus (MRSA) strains by well diffusion method. Significantly high antiviral and antibacterial activities were observed from nanosilver particles against AIV H9N2 and all four MRSA strains.Keywords:

2020 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mitra Omidi ◽  
Mahmood Saffari ◽  
Hossein Sedaghat ◽  
Mohammad Zibaei

Abstract Background: The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan. Methods: A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antibiotic resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multi-locus sequence type and SCC mec typing. Results: Of 146 Staphylococcus aureus isolates 24 (16.4%) isolates identified as MRSA strains. According to antibiotic susceptibility testing the highest resistance rates were seen to erythromycin, cefoxitin and clindamycin. All of Staphylococcus aureus isolates were sensitive to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCC mec types were obtained among MRSA strains including 16 (66.7%) SCC mec type V, 3 (12.5%) SCC mec type III and 5 (20.8%) SCC mec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%) , cna (25.0%), fnbB (16.6%) , ebps 5 (20.8%), and fnbA , bbp and clfA genes were not detected. MLST analysis revealed 11 sequence types among MRSA isolates as follows: ST239, ST239, ST291, ST22, ST861, ST 889, ST8, ST59, ST343, ST772, ST6 and ST1465. Also seven MLST-based clonal complexes (CCs) were identified among MRSA strains including: CC8, CC7, CC398, CC59, CC22, CC1 and CC5. Conclusions: A relatively high diversity was found in MRSA genotypes in Kashan and Isfahan hospitals, and seven clonal complexes were identified. Pandemic MRSA clones including CC8 and CC22 were the most prevalent clones and the novel ST types including ST1465, ST861, ST 889 and ST772 are reported for the first time in Iran in the present study. In addition the high prevalence of MSCRAMMs genes in MRSA isolates demonstrates the high potential of these strains for pathogenicity.


2020 ◽  
Vol 73 (12) ◽  
pp. 2563-2567
Author(s):  
Aidyn G. Salmanov ◽  
Taras P. Bondar ◽  
Yaroslav V. Shkorbotun ◽  
Evelina A. Chumak ◽  
Volodymyr O. Shkorbotun ◽  
...  

The aim: To obtain the first estimates of the current prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) in the departments of Otorinolaryngology and Dentistry and to determine of genes virulence factors (Panton Valentine Leukocidine (PVL) genes). Materials and methods: We performed a multicenter cross-sectional study. The susceptibility to antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing. The virulence factor encoding genes, mecA, lukS-lukF, were detected by Polymerase Chain Reaction (PCR). Results: Incidence rate of S. aureus nasal carriage among HCWs was 36.2%, whereas MRSA carriage was 17%. Prevalence of MRSA carriage rate was 34.9% in Otorhinolaryngology departments and 9.7% in Dentistry. PCR testing confirmed that all MRSA strains were mecA gene-positive. The virulence factor encoding genes were detected in 82.3% of the S. aureus isolates from HCWs. Among S.aureus, the lukS-lukF genes were detected in over 59% of the strains. The lukS-lukF genes were detected in 55.5% of MRSA and in 58.9% of MSSA strains. LukS-lukF genes were most commonly co-present in MRSA strains. No significant difference was detected between the occurrences of lukS-lukF genes (P > 0.05). Conclusions: Personnell in otorhinolaryngology and dentistry departments have a high rate of nasal colonization of MRSA. This carrier state may be an important risk factor for transmission MRSA from physicians and nurses to patients and vice-versa. Screening for MRSA nasal carriage of HCWs is a key element in enabling infection control measures and early therapeutic decisions.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 439 ◽  
Author(s):  
Vanessa Silva ◽  
Telma de Sousa ◽  
Paula Gómez ◽  
Carolina Sabença ◽  
Madalena Vieira-Pinto ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) are one of the main pathogens associated with purulent infections. MRSA clonal complex 97 (CC97) has been identified in a wide diversity of livestock animals. Therefore, we aimed to investigate the antibiotic resistance profiles of MRSA strains isolated from purulent lesions of food-producing rabbits. Samples from purulent lesions of 66 rabbits were collected in a slaughterhouse in Portugal. Samples were seeded onto ORSAB plates with 2 mg/L of oxacillin for MRSA isolation. Susceptibility to antibiotics was tested by the disk diffusion method against 14 antimicrobial agents. The presence of resistance genes, virulence factors and the immune evasion cluster (IEC) system was studied by polymerase chain reaction. All isolates were characterized by multilocus sequence typing (MLST), agr and spa typing. From the 66 samples analyzed, 16 (24.2%) MRSA were detected. All strains were classified as multidrug-resistant as they were resistant to at least three classes of antibiotics. All isolates showed resistance to penicillin, erythromycin and clindamycin. Seven isolates were resistant to gentamicin and harbored the aac(6′)-Ie-aph (2″)-Ia gene. Resistance to tetracycline was detected in 10 isolates harboring the tet(K) gene. The IEC genes were detected in three isolates. MRSA strains belonged to CC97, CC1, CC5, CC15 or CC22. The isolates were assigned to six different spa types. In this study we found a moderate prevalence of multidrug-resistant MRSA strains in food-producing rabbits. This may represent concern for food safety and public health, since cross-contamination may occur, leading to the spread of MRSA and, eventually, the possibility of ingestion of contaminated meat.


1970 ◽  
Vol 6 (1) ◽  
pp. 1-6 ◽  
Author(s):  
RK Sanjana ◽  
Rajesh Shah ◽  
Navin Chaudhary ◽  
YI Singh

Aims: Nosocomial infection is a major problem in the world today. Methicillin-resistant Staphylococcus aureus (MRSA) strains, usually resistant to several antibiotics and also intrinsic resistance to ß-lactam antibiotics, shows a particular ability to spread in hospitals and now present in most of the countries. The present study was carried out to investigate the prevalence of MRSA and their rate of resistance to different antistaphylococcal antibiotics. Materials and methods: Between April 2007 and December 2009, the clinical specimens submitted at the microbiology laboratory were processed and all Staphylococcus aureus (S. aureus) isolates were included in this study. All isolates were identified morphologically and biochemically by standard laboratory procedures and antibiotic susceptibility pattern including oxacillin was determined by modified Kirby Bauer disc diffusion method. Results: Out of a total of 348 Staphylococcus aureus strains isolated from various clinical samples, 138 (39.6%) were found to be Methicillin-resistant. Among MRSA isolates, 86(62.3%) were from different inpatient departments, whereas, 52(37.7%) of the isolates were from outpatients. All MRSA were resistant to penicillin. More than 70% of the MRSA strains were resistant to cephalexin, ciprofloxacin and cloxacillin, while less than 10% of them were resistant to azithromycin, amikacin and tetracycline. Many MRSA strains were multidrug resistant. However, no strains were resistant to vancomycin. Conclusion: This preliminary report showed a high prevalence of MRSA in our hospital. To reduce the prevalence of MRSA, regular surveillance of hospital acquired infection and isolation is the need of the hour. Key words: Nosocomial infection; methicillin-resistant Staphylococcus aureus (MRSA); multidrug resistant. DOI: 10.3126/jcmsn.v6i1.3595 Journal of College of Medical Sciences-Nepal, 2010, Vol. 6, No. 1, 1-6


2000 ◽  
Vol 38 (8) ◽  
pp. 2985-2988 ◽  
Author(s):  
François Guerin ◽  
Annie Buu-Hoï ◽  
Jean-Luc Mainardi ◽  
Guillaume Kac ◽  
Nathalie Colardelle ◽  
...  

Epidemiological relationships were investigated between 40 methicillin-resistant Staphylococcus aureus (MRSA) strains with decreased glycopeptide susceptibility isolated from November 1998 to March 1999 from 39 patients (17 infected and 22 colonized patients) in nine wards of the Broussais Hospital, Paris, France. Reduced glycopeptide susceptibility was readily detected on brain heart infusion (BHI) agar containing 6 μg of teicoplanin per ml and on gradient plates, but not by the standard disk diffusion method. The MICs of vancomycin and teicoplanin, determined on BHI agar, were 4 and 8 to 32 μg/ml, respectively (standard antibiotic dilution), and 4 to 8 and 8 to 32 μg/ml, respectively (E-test). All strains were resistant to macrolides, aminoglycosides, tetracycline, rifampin, sulfonamides, and pefloxacin, showed reduced susceptibility to fusidic acid and fosfomycin, and were susceptible to trimethoprim and chloramphenicol. Pulsed-field gel electrophoresis and lysotyping revealed that a multidrug-resistant MRSA clone with decreased susceptibility to glycopeptides has been discretely endemic since at least 1996 in our institution, where it was responsible for an outbreak in November and December 1998.


2018 ◽  
Vol 2 (1) ◽  

Aim: In today’s scenario, Nosocomial infection is a foremost problem in world. Methicillin resistant staphylococcus aureus (MRSA) strains are not only resistant to several antibiotics but also, show a particular ability to spread in hospitals of many countries. The main objective of the present study is to determine the prevalence of MRSA in surgical wound infections and also to define the antimicrobial susceptibility patterns of the strains isolated. Materials and Methods: A total of 133 culture positive Staph.aureus were taken from surgical site wound infections for the study during the period from March 2016 to February 2017. Routine Antibiotic Susceptibility testing was performed and interpreted as per latest CLSI guidelines. Methicillin resistance was detected using cefoxitin disc diffusion method. Results: In total of 133 samples, 81 (60.9%) were found to be MRSA. However, no strain was resistant to Vancomycin, Linezolid or Teichoplanin. Conclusion: Vigorous antimicrobial stewardship and strengthened infection control practices are mandatory to prevent spread and reduce emergence of resistance. Customary surveillance of hospital-associated infection and monitoring of antibiotic sensitivity pattern is required to reduce MRSA prevalence.


2008 ◽  
Vol 47 (170) ◽  
Author(s):  
Namrata Kumari ◽  
TM Mohapatra ◽  
YI Sigh

Nosocomial infection is a major problem in the world today. Methicillin-resistant Staphylococcus aureus (MRSA) strains, usually resistant to several antibiotics, shows a particular ability to spread inhospitals and is now present in most of the countries.The aim of the present study was to determine the prevalence of MRSA infections and theirantimicrobial susceptibility pattern in our hospital located in eastern Nepal.Identification of Staphylococcus aureus was confirmed by standard methods and the antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method. Interpretation criteriawere those of the national committee for clinical laboratory standards.During a period of one year, out of a total of 750 Staphylococcus aureus strains isolated from variousclinical samples, 196 (26.14%) were found to be Methicillin-resistant. Seventy percent isolates of MRSA were from inpatient departments and amongst them only 10% of the isolates were from intensive care units (ICU). More than 65% of MRSA were found to be resistant to Penicillin, Cephalosporins, Ciprofloxacin, Gentamicin Erythromycin and Tetracycline, while 47.96% of them were resistant to Amikacin. Many MRSA strains were multidrug-resistant. However, no strains were resistant toVancomycin.To reduce the prevalence of MRSA, the regular surveillance of hospital acquired infection, isolationnursing of patients who carry MRSA, monitoring of antimicrobial susceptibility pattern andformulation of a definite antibiotic policy may be helpful.Key words:eastern Nepal, resistant, tertiary-care hospital


2020 ◽  
Vol 1 (1) ◽  
pp. 9-15
Author(s):  
Mehwish Tanveer ◽  
Hira Musaddiq ◽  
Atia Iqbal ◽  
Sarwat Saleem ◽  
Sadia Iqbal ◽  
...  

2-Substituted 1,3-Thiazolidine-4-Carboxylic Acids (1-11) were synthesized and screened for their anti-methicillin-resistant Staphylococcus aureus (MRSA) potential. The synthesized compounds were evaluated for their antibacterial activities against four MRSA strains MRSA I, VI, VII and VIII with accession numbers KU662352, KR862285, KR862291 and KU662354 respectively by well diffusion method. In addition, antibacterial evaluations were also performed for gram positive strain Bacillus subtilis and gram-negative strains klebsiella pneumoniae and pseudomonas aeruginosa using same method. Most of the synthesized thiazolidine-4-carboxylic acid derivatives exhibited better antibacterial activities against studied bacterial strains. Amongst the synthesized compounds, 8-10 were found to possess significant activity (Zone in mm) against methicillin-resistant Staphylococcus aureus in addition to the other studied bacterial strains.


2021 ◽  
Vol 11 (7) ◽  
pp. 3206
Author(s):  
Lorina I. Badger-Emeka ◽  
Promise Madu Emeka ◽  
Hairul Islam M. Ibrahim

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 395
Author(s):  
Katarina Pomorska ◽  
Vladislav Jakubu ◽  
Lucia Malisova ◽  
Marta Fridrichova ◽  
Martin Musilek ◽  
...  

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.


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