scholarly journals In VitroSynergistic Effect ofPsidium guineense(Swartz) in Combination with Antimicrobial Agents against Methicillin-ResistantStaphylococcus aureusStrains

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tiago Gomes Fernandes ◽  
Amanda Rafaela Carneiro de Mesquita ◽  
Karina Perrelli Randau ◽  
Adelisa Alves Franchitti ◽  
Eulália Azevedo Ximenes
Keyword(s):  
Staphylococcus Aureus ◽  
Aqueous Extract ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Synergistic Activity ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Fold Reduction ◽  
Amoxicillin Clavulanic Acid ◽  
Mrsa Strains

The aim of this study was to evaluate the antimicrobial activity of aqueous extract ofPsidium guineenseSwartz (Araçá-do-campo) and five antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, ciprofloxacin, and meropenem) against twelve strains ofStaphylococcus aureuswith a resistant phenotype previously determined by the disk diffusion method. FourS. aureusstrains showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between aqueous extract ofP. guineenseand antimicrobial agents, by the checkerboard method. The criteria used to evaluate the synergistic activity were defined by the fractional inhibitory concentration index (FICI). AllS. aureusstrains were susceptible toP. guineenseas determined by the microdilution method. The combination of theP. guineenseextract with the antimicrobial agents resulted in an eight-fold reduction in the MIC of these agents, which showed a FICI ranging from 0.125 to 0.5, suggesting a synergistic interaction against methicillin-resistantStaphylococcus aureus(MRSA) strains. The combination of the aqueous extract ofP. guineensewith cefoxitin showed the lowest FICI values. This study demonstrated that the aqueous extract ofP. guineensecombined with beta lactamics antimicrobials, fluoroquinolones, and carbapenems, acts synergistically by inhibiting MRSA strains.

scholarly journals Livestock-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) in Purulent Subcutaneous Lesions of Farm Rabbits

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 439 ◽  
Author(s):  
Vanessa Silva ◽  
Telma de Sousa ◽  
Paula Gómez ◽  
Carolina Sabença ◽  
Madalena Vieira-Pinto ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Resistance To Penicillin ◽  
Mrsa Strains

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.

scholarly journals Fluoroquinolone Therapy in Staphylococcus aureus Infections: Where Do We Stand?

2013 ◽  
Vol 5 (02) ◽  
pp. 109-112 ◽  
Author(s):  
Neeta D Gade ◽  
Mohiuddin S Qazi
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Empirical Therapy ◽  
Phage Typing ◽  
Diffusion Method ◽  
New Delhi ◽  
Disk Diffusion Method ◽  
Medical College ◽  
Drug Of Choice ◽  
Mrsa Strains

ABSTRACT Aim: The study aimed to evaluate the utility of various commonly used fluoroquinolones against Staphylococcus aureus isolates. Materials and Methods: A total of 250 isolates of S. aureus were studied from different clinical specimens like blood, pus, wound swabs, sputum, ear swabs, and body fluids between November 2009 and December 2011. All the isolates were tested for their susceptibility to fluoroquinolones and other antimicrobial agents by Kirby-Bauer disc diffusion method using criteria of standard zone of inhibition. Methicillin-resistant S. aureus (MRSA) detection was done by cefoxitin disk diffusion method. The MRSA isolates were tested for minimum inhibitory concentration (MIC) to vancomycin by E-test strips. All the MRSA strains were sent to National Staphylococcal Phage-typing Centre, Maulana Azad Medical College, New Delhi for phage typing. Results: A total of 107 strains of S. aureus (42.8%) were detected as MRSA. Multidrug resistance was observed among the MRSA strains more commonly than among the MSSA stains. Among the fluoroquinolones, maximum resistance in MRSA was seen to ciprofloxacin (92.5%), followed by ofloxacin (80.4%). None of the S. aureus isolates showed resistance to vancomycin and linezolid. The MICs of vancomycin for the MRSA tested ranged from 0.5 to 2 μg/ml. Phage typing pattern of 107 MRSA isolates revealed that 37 (34.6%) MRSA isolates were nontypeable and 70 (65.4%) were typeable. Conclusion: Ciprofloxacin can no longer be used in empirical therapy against MRSA infections. Use of other members of fluoroquinolone should be limited only to those strains that show laboratory confirmation of their susceptibility. Vancomycin remains the drug of choice to treat MRSA infections.

scholarly journals Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Bloodstream Infection ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

scholarly journals Comparison of methods for the determination of antimicrobial resistance in Campylobacter spp. human and the food chain isolates

2008 ◽  
Vol 52 (No. 4) ◽  
pp. 169-174
Author(s):  
M. Holasova ◽  
R. Karpiskova ◽  
S. Karpiskova ◽  
V. Babak ◽  
J. Schlegelova
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Study Results ◽  
Agar Dilution

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain <i>Campylobacter jejuni</i> ATCC 33560 and 73 thermo-tolerant isolates of <i>Campylobacter</i> spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MIC<sub>R</sub>) for ciprofloxacin &ge; 0.5, erythromycin &ge; 4, gentamicin &ge; 4, nalidixic acid &ge; 32 and tetracycline &ge; 4 &mu;g/ml. On the basis of our study results, strains resistant to clindamycin were MIC<sub>R</sub> &ge; 2 &mu;g/ml for the dilution methods and a zone diameter R ≤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MIC<sub>R</sub> of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.

scholarly journals Genetic Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Human Bloodstream Infections: Detection of MLSB Resistance

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 375
Author(s):  
Vanessa Silva ◽  
Sara Hermenegildo ◽  
Catarina Ferreira ◽  
Célia M. Manaia ◽  
Rosa Capita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Accessory Gene ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant

In this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.

scholarly journals Antibacterial activity of Achillea tenuifolia Lam. extract against standard bacteria and isolated strains

2016 ◽  
Vol 2 (2) ◽  
pp. 49
Author(s):  
Sahar Omidpanah ◽  
Abbas Hadjiakhondi ◽  
Azadeh Manayi
Keyword(s):  
Room Temperature ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Inhibition Zone ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Different Sources ◽  
Freeze Dryer

Researchers have been trying to develop new broad-spectrum antibiotics against the infectious diseases caused by bacteria, fungi, viruses, and parasites for many decades. Prolonged usage of the antibiotics has led to the emergence of drug resistance among bacteria; therefore, there is a tremendous need for novel antimicrobial agents from different sources such as plants which are used in traditional medicine. The aim of this study was to evaluate antibacterial effect of <em>Achillea tenuifolia</em>.<em> </em>The plant material was extracted by maceration method using methanol three times at room temperature. The extract was concentrated after removing the solvent by rotary evaporator and then lyophilized using freeze dryer. Inhibitory effect of the extract was examined against four standard bacteria strains and two isolated strains from diseased hen using disk diffusion method and microdilution method to evaluate their inhibition zone diameter (IZD) and minimum inhibitory concentration (MIC), respectively. The results showed that the extract of the plant was active against standard strains including <em>Escherichia coli</em>, <em>Pseudomonas aeruginosa</em>, <em>Staphylococcus aureus </em>and <em>Enterococcus faecalis </em>with IZDs of 10.3±0.5, 14±0.0, 12±0.0 and 11.6±0.5, respectively.<strong> </strong>However, growths of isolated strains were not inhibited in the presence of the extract. Although, the growths of isolated strains were not inhibited by the plant extract, the standard strains were moderately susceptible to the extract; among those <em>P. aeroginosa</em> was more sensible than other tested strains

scholarly journals Prevalence, seasonality, and antimicrobial resistance of thermotolerant Campylobacter isolated from broiler farms and slaughterhouses in East Algeria

2020 ◽  
Vol 13 (6) ◽  
pp. 1221-1228
Author(s):  
Mohamed Baali ◽  
Mohamed Lounis ◽  
Hanan Laidouci Al Amir ◽  
Ammar Ayachi ◽  
Ahcen Hakem ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Antimicrobial Agents ◽  
Health Hazard ◽  
Control Measures ◽  
Diffusion Method ◽  
Contamination Rate ◽  
Isolation And Identification ◽  
Initial Finding ◽  
Disk Diffusion Method ◽  
Amoxicillin Clavulanic Acid

Aim: The current study was carried out to determine the prevalence, seasonality, and antimicrobial profile of thermotolerant Campylobacter isolated from broiler chickens in Batna, East Algeria, from June 2016 to June 2018. Materials and Methods: A total of 960 samples, including 480 cloacal swabs, 240 cecal contents, and 240 neck skin samples collected from 6 poultry farms and 12 slaughterhouses, were included in this study. After isolation and identification, susceptibility to seven antimicrobial agents was tested by the disk diffusion method. The seasonality of Campylobacter infection at broiler farms was statistically analyzed. Results: The data showed that 65%, 55%, and 70% of the cloacal swab, neck skin, and cecal content samples were contaminated with thermotolerant Campylobacter strains, respectively (p<0.05). Among the isolated campylobacteria, Campylobacter jejuni was the predominant species (73.5%). Sampling season exhibited a significant impact on the prevalence of Campylobacter (p<0.01), with peak occurrence in summer. All of the isolates were susceptible to gentamicin and resistant to ampicillin and amoxicillin/clavulanic acid, while 83.3% of them were resistant to erythromycin. Interestingly, 16 different resistance profiles were noted, with the combination of "ampicillin, amoxicillin/clavulanic acid, chloramphenicol, erythromycin, and tetracycline" being the most common, identified in 20.7% of isolated strains. Conclusion: This study demonstrates the presence of a high contamination rate of multidrug-resistant Campylobacter in farms and slaughterhouses in East Algeria. These findings underscore the need to apply strict control measures to avoid any associated public health hazard among Algerian consumers. This initial finding of the contamination of poultry with this zoonotic pathogen in East Algeria suggests the value of periodic comprehensive evaluation of associated disease in poultry as well as in humans in this region.

scholarly journals Aqueous Extract of Wild Cyclamen Tubers (Cyclamen Purpurascens L.) - A Potential Source of Natural Antioxidants and Antimicrobial Agents

2018 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Ljiljana P. Stanojević ◽  
Milorad D. Cakić ◽  
Jelena S. Stanojević ◽  
Dragan J. Cvetković ◽  
Bojana R. Danilović
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Aqueous Extract ◽  
Antimicrobial Agents ◽  
Natural Antioxidants ◽  
Diffusion Method ◽  
Total Phenolic ◽  
Dry Extract ◽  
Potential Source ◽  
Total Flavonoids Content

Wild cyclamen tubers (Cyclamen purpurascens Mill.) (mountain Kukavica, Southeast Serbia) were used as material for extraction in this study. Aqueous extract was obtained by reflux extraction on boiling temperature with hydromodulus 1:20 m/v during 180 minutes. The total phenolic content was determined spectrophotometrically by the method of Folin-Ciocalteu, and the total flavonoids content by method with AlCl3. The antioxidant activity of extract was investigated spectrophotometrically by DPPH and ABTS test. Disc-diffusion method was used for antimicrobial activity investigation on the following pathogenic microorganisms: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Pseudomonas aeruginosa and Klebsiella pneumoniae. The content of total phenols was 8.27 mg GAE/g dry extract while the total flavonoid content was 11.51 mg RE/g dry extract. The extract concentrations required to neutralize 50% of the initial concentration of DPPH radicals (EC50) after 20 minutes incubation and immediately after adding DPPH radical solution were 0.413 and 2.0 mg/ml, respectively, while concentrations of extract required to neutralize 50% of the initial ABTS radicals concentration is 0.743 mg/ml. The extract showed the highest antimicrobial activity on bacteria Staphylococcus aureus. The presented results indicate that cyclamen tubers extract is a potential source of natural antioxidants and antimicrobial agents.

scholarly journals Effects of Carvacrol on Staphylococcus aureus isolated from bulk tank milk

2019 ◽  
Vol 75 (02) ◽  
pp. 6211-2019
Author(s):  
ERHAN KEYVAN ◽  
HIDAYET TUTUN
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Multidrug Resistant ◽  
Culture Collection ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Bulk Tank Milk ◽  
Microdilution Method ◽  
Bulk Tank ◽  
Susceptibility Profiles

The occurrence of multidrug-resistant Staphylococcus aureus is an important causative agent of mastitis in cattle and of foodborne diseases. It is a worldwide concern, making it essential to develop alternative treatments to fight against the bacteria. Thus, the aim of this study is to determine the ability of carvacrol to inhibit the growth of S. aureus isolated from bulk tank milk in Turkey’s Burdur Province. All strains (n = 31) were used to investigate the antimicrobial activity of carvacrol, including the methicillin-resistant S. aureus and strains from the American Type Culture Collection and England’s National Collection of Type Cultures. The minimum inhibitory concentration (MIC) values were determined via a microdilution method, and the antimicrobial susceptibility profiles via a disk diffusion method. Antibiotic resistance was detected in 20 strains (64.5%). Multidrug resistance was observed in 8 strains (25.8%). Carvacrol exhibited strong antimicrobial activity, with MIC value at 0.058-0.234 mg/ml, in the microdilution method. Inhibition zones of carvacrol were in the range of 19 to 45 mm. The results of this study emphasize the promising role of carvacrol among new antibacterial agents that can combat S. aureus strains.

scholarly journals Antimicrobial susceptibility of Actinobacillus pleuropneumoniae strains isolated from pig's clinical samples in Serbia

2016 ◽  
Vol 72 (10) ◽  
pp. 637-640
Author(s):  
Jadranka Žutić ◽  
Ljiljana Pavlović ◽  
Oliver Radanović ◽  
Vladimir Radosavljević ◽  
Branislav Kureljušić ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Antimicrobial Agents ◽  
Actinobacillus Pleuropneumoniae ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Disk Diffusion Method ◽  
Bacterial Diseases ◽  
Porcine Pleuropneumonia ◽  
Amoxicillin Clavulanic Acid ◽  
Resistance Rates

Porcine pleuropneumonia, caused by Actinobacillus pleuropneumoniae is one of the most important bacterial diseases of the pig respiratory tract. One hundred and forty eight Actinobacillus pleuropneumoniae strains isolated from pig's clinical samples were tested for their susceptibility to 11 antimicrobials by disk diffusion method. Isolates were obtained from the pathoanatomically altered pig's lung that died with signs of respiratory disease. Antimicrobial discs with following concentration were used: ampicillin 10 µg, amoxicillin 10 µg, amoxicillin/clavulanic acid 20/10 µg, cefotaxime 30 µg, gentamicin 10 µg, penicillin 10 IU, streptomycin 10 µg, tetracycline 30 µg, enrofloxacin 5µg, lincospectin 15/200 µg, florfenicol 30 µg and trimethoprim/sulfamethoxazole 1.25/23.75 µg. Isolated strains showed various susceptibility to tested antimicrobials. Seventy-five percent of isolates were resistant to one or more drugs frequently used in the treatment of pig's diseases at farms in Serbia. All 148 isolates were susceptible to cefotaxime, enrofloxacin and florfenicol, while 96% of them were susceptible to amoxicillin/clavulanic acid and lincospectin. Susceptibility of isolates to amoxicillin, gentamicin and trimethoprim/sulfamethoxazole were 91%, 77% and 64%, respectively. The highest resistance rates were determined for tetracycline and streptomycin, 34% and 31%, respectively. When compared to our previous results, we noticed a decrease in resistance to tetracyclines and trimethoprim/sulfamethoxazole. Our results indicate that A. pleuropneumoniae strains isolated from pig's clinical samples in Serbia show high susceptibility to antimicrobial agents which are most often used in the pig industry.

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