scholarly journals Synergy between antibiotics and natural agents results in increased antimicrobial activity against Staphylococcus epidermidis

2015 ◽  
Vol 9 (09) ◽  
pp. 925-929 ◽  
Author(s):  
Syed Hani Abidi ◽  
Khalid Ahmed ◽  
Sikander Khan Sherwani ◽  
Shahana Urooj Kazmi
Keyword(s):  
Camellia Sinensis ◽  
Staphylococcus Epidermidis ◽  
Juglans Regia ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Synergistic Activity ◽  
Disk Diffusion Method ◽  
Antimicrobial Potential ◽  
Natural Agents

Introduction: Staphylococcus epidermidis is one of the most frequent causes of biofilm-associated infections on indwelling medical devices. With the emergence of methicillin-resistant S. epidermidis (MRSE), there is an urgent need to discover novel active agents against a range of Gram-positive pathogens. We screened the clinical isolates of S. epidermidis for susceptibility/resistance against commonly prescribed antibiotics. Furthermore, we tested some natural agents alone and in combination with antibiotics to find possible synergistic antimicrobial effects. Methodology: S. epidermidis clinical isolates were screened for susceptibility/resistance against vancomycin, erythromycin, tetracycline, chloramphenicol, ampicillin, ofloxacin, cephalexin, and gentamicin using the Kirby-Bauer disk diffusion method. The antimicrobial potential of Camellia sinensis, Juglans regia, and Hippophae rhamnoides alone and in combination with antibiotics were examined using the disk diffusion method, where the antimicrobial potential activity was measured in terms of formation of zones of inhibition. Results: Most S. epidermidis isolates were found to be resistant to one or more antibiotics. Gentamycin and ofloxacin were found to be the most effective antibiotics against S. epidermidis isolates. Extracts of Hippophae rhamnoides, Juglans regia, and Camellia sinensis were found to be equally effective against S. epidermidis isolates. In combination with antibiotics, these extracts exhibited appreciable synergistic activity; the highest synergistic activity was observed with erythromycin and cephalexin. In the case of cephalexin, a reversion in resistance was observed. Conclusions: The plant extracts used in the study exhibited additive and synergistic antibacterial activity against S. epidermidis, hence providing an effective alternative to deal with the problem of multidrug resistance.

Activity of Caspofungin and Voriconazole against Clinical Isolates of Candida and Other Medically Important Yeasts by the CLSI M-44A Disk Diffusion Method with Neo-Sensitabs Tablets

Chemotherapy ◽  
2007 ◽  
Vol 54 (1) ◽  
pp. 38-42 ◽  
Author(s):  
A.J. Carrillo-Muñoz ◽  
G. Quindós ◽  
O. del Valle ◽  
P. Santos ◽  
G. Giusiano ◽  
...  
Keyword(s):  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method

scholarly journals Vibrio alginolyticusAssociated Chronic Myringitis Acquired in Mediterranean Waters of Turkey

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Burak Ekrem Citil ◽  
Serhan Derin ◽  
Funda Sankur ◽  
Murat Sahan ◽  
Mahmut Ugur Citil
Keyword(s):  
Antimicrobial Susceptibility ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Alginolyticus ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
External Ear ◽  
Disk Diffusion Method ◽  
Ear Infections

Vibrio alginolyticuswas originally classified as biotype 2 ofVibrio parahaemolyticus. Most clinical isolates are recovered from superficial wounds or the external ear infections.V. alginolyticusis acknowledged to be nearly nonpathogenic in humans. The reason for presence ofV. alginolyticus’s virulence is uncertain. We describe a chronic myringitis case in a 47-year-old female due toV. alginolyticus. According to her anamnesis, it was detected that she had sea bathing history in Mugla Coast in Turkey. Pure isolation ofV. alginolyticuswas obtained from external auditory canal’s culture. Investigation and antimicrobial susceptibility of the isolate were performed by the automatized BD Phoenix system and Kirby-Bauer disk diffusion method, respectively. The bacteria were sensitive to all antibiotics. This case was presented to pay attention toVibrio alginolyticusinfections.

scholarly journals Categorizing susceptibility of clinical isolates of Candida auris to amphotericin B, caspofungin, and fluconazole utilizing the CLSI M44-A2 disk diffusion method

2021 ◽  
Author(s):  
Natalie S. Nunnally ◽  
Tajah Damm ◽  
Shawn R. Lockhart ◽  
Elizabeth L. Berkow
Keyword(s):  
Amphotericin B ◽  
Accurate Method ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Candida Auris ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method

We evaluated the CLSI M44ed3E disk diffusion method in comparison with the CLSI M27ed4 broth microdilution method for caspofungin and fluconazole and the Etest method for amphotericin B to categorize susceptibility of 347 clinical isolates of Candida auris. Utilizing the zone diameter cutoffs established here we observed the overall categorial agreement between the two methods. For caspofungin, concordant results were observed for 98% of isolates with <1% very major and 1% major errors. For fluconazole, concordant results were observed for 91% of isolates with 1% very major and 8% major errors. For amphotericin B, concordant results were observed for 74% of isolates with <1% very major errors and 25% major errors. The disk diffusion approach provides an accurate method for determining the susceptibility of C. auris for caspofungin and fluconazole, and for identification of at least 75% of amphotericin B-susceptible isolates.

scholarly journals A study of inducible clindamycin resistance in erythromycin resistant clinical isolates of Staphylococcus species

2015 ◽  
Vol 6 (6) ◽  
pp. 48-52
Author(s):  
Fatima Khan ◽  
Sana Ali ◽  
Asfia Sultan ◽  
Meher Rizvi ◽  
Abida Khatoon ◽  
...  
Keyword(s):  
Methicillin Resistance ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Clinical Failure ◽  
Coagulase Negative Staphylococci ◽  
Sensitivity Testing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance

Introduction: Erythromycin resistant Staphylococcus isolates with inducible resistance appear sensitive to clindamycin in in?vitro sensitivity testing. If clindamycin is used for treatment of such isolates, selection for constitutive mutants may lead to clinical failure. Current study was conducted to detect the presence of inducible clindamycin resistance in erythromycin resistant Staphylococcus isolates by disk diffusion method (D test). To correlate clindamycin resistance phenotypes with minimum inhibitory concentrations (MICs) of clindamycin, erythromycin, oxacillin and vancomycin among the isolates. To correlate various resistance phenotypes with methicillin resistance. Material and Methods: 150 non duplicate isolates of Staphylococcus species were identified and antibiotic susceptibility testing was done using Kirby Bauer’s disc diffusion method. MICs were determined using E?test for oxacillin, vancomycin, clindamycin and erythromycin using E?test strips (Himedia) Results: Among 150 staphylococcus clinical isolates, 96 were of S. aureus and 54 were coagulase negative Staphylococci (CONS). About 81.2% of the S.aureus isolates and 72.2% of the CONS were found to be methicillin resistant. Inducible clindamycin resistance was found in 39.3% of the isolates, constitutive resistance phenotype in 48% while 12.7% demonstrated MS phenotype. 18% and 11.3% of all the isolates had MICs for clindamycin between 0.01?0.06 μg/ml and 0.06?0.1 respectively. 12.5% had MIC ranging from 4?8 μg/ml while 58% had MIC > 8 μg/ml. Constitutive resistant phenotype (cMLS) was the predominant phenotype in methicillin resistant isolates. MS phenotype was the predominant among MSSA (methicillin sensitive S. aureus) while MSCNS (methicillin sensitive CONS) cMLS (46.7%) predominated. MIC of all erythromycin resistant isolates were ≥ 240 μg/ml. Nearly 16.7% of the cMLS and 57.9% of MS isolates were found to be oxacillin sensitive and 83% of iMLS and 83.3% of MS phenotype isolates were oxacillin resistant on MIC testing. 47.2% of cMLS and 73.6% of MS isolates had MIC ≤ 2 μg/ml for vancomycin and 52.7% of cMLS and 26.3% of MS isolates had MICs in intermediate range for vancomycin. Conclusions: D?testing might help clinicians to decide whether to use clindamycin in Staphylococcal infections when erythromycin resistance is present. Determination of MICs help to identify exact sensitivity profile of isolates in cases where clinical failure occurs due to misleading disk diffusion tests.DOI: http://dx.doi.org/10.3126/ajms.v6i6.11811 Asian Journal of Medical Sciences Vol.6(6) 2015 48-52

scholarly journals Levonadifloxacin: A Novel Approved Drug Exhibiting Potent In vitro Activity against Gram Positive Bacterial Isolates from Patients Admitted in Intensive Care Units

2021 ◽  
Author(s):  
Tasneem Siddiqui ◽  
Rafat Shamim ◽  
Sangram Singh Patel ◽  
Chinmoy Sahu
Keyword(s):  
Staphylococcus Aureus ◽  
Intensive Care ◽  
Intensive Care Units ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Gram Positive ◽  
Disk Diffusion Method ◽  
Methicillin Resistant

Introduction: Levonadifloxacin is a novel antibiotic belonging to the benzoquinolizine subclass of fluoroquinolone with potent activity against Methicillin Resistant Staphylococcus aureus (MRSA) and Quinolone Resistant Staphylococcus aureus (QRSA). Both intravenous levonadifloxacin and its oral formulation have recently been approved in India for the treatment of acute bacterial skin related infections. Aim: To assess the activity of levonadifloxacin against gram positive clinical isolates collected from Intensive Care Units (ICUs) using the disk-diffusion method. Materials and Methods: The present descriptive study where non duplicate isolates of Staphylococcus aureus (S. aureus) and other gram positive isolates from various clinical samples from all Intensive Care Units (ICUs) were collected from June to December 2020 and subjected to levonadifloxacin susceptibility testing (disk diffusion method) as per the Clinical and Laboratory Standards Institute (CLSI) guidelines, 2020. Data analysis was performed using Statistical Package for the Social Sciences (SPSS) software, version 25.0. Results: A total of 142 gram positive clinical isolates collected from all ICUs of the hospital were analysed. These isolates included coagulase negative S. aureus 109 (76.8%), S. aureus 21 (14.8%) and Enterococcus faecalis 12 (8.4%). All the gram positive isolates of the study were susceptible to levonadifloxacin as per the prespecified interpretive criteria identified based on population pharmacokinetic model and Monte Carlo simulation enabled probability of pharmacodynamic target attainment analysis. Conclusion: Results of this in vitro study shows good activity of levonadifloxacin against gram positive isolates including difficult to-treat methicillin resistant staphylococcal isolates collected from ICU patients.

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