scholarly journals Detection of Methicillin ResistantStaphylococcus aureusand Determination of Minimum Inhibitory Concentration of Vancomycin forStaphylococcus aureusIsolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Raghabendra Adhikari ◽  
Narayan Dutt Pant ◽  
Sanjeev Neupane ◽  
Mukesh Neupane ◽  
Roshan Bhattarai ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Meca Gene ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Disc Diffusion Method ◽  
Inducible Clindamycin Resistance ◽  
Microdilution Method ◽  
Broth Microdilution Method

The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistantS. aureus(MRSA), taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC) of vancomycin forS. aureusisolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. TheStaphylococcus aureuswas identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47%)S. aureusisolates were recovered, of which 39 (35.50%) isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of theStaphylococcus aureusisolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% ofS. aureusisolates. The MIC value of vancomycin forS. aureusranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%), both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

The role of the bla KPC gene in antimicrobial resistance of Klebsiella pneumoniae

2019 ◽  
Author(s):  
Atossa Ghasemnejad ◽  
Monir Doudi ◽  
Nour Amirmozafari
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antimicrobial Susceptibility ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Disc Diffusion Method ◽  
Biochemical Tests ◽  
Microdilution Method ◽  
Broth Microdilution Method

Background and Objectives: Klebsiella pneumoniae isolates that produce K. pneumoniae carbapenemase (KPC) have be- come a grave concern for the treatment of infections. KPC-producing strains are not only able to hydrolyze carbapenems but are also resistant to a variety of β-lactam and non-β-lactam antibiotics. The present study evaluated the prevalence of bla in K. pneumoniae infections and determined the antimicrobial susceptibility of the isolates. Materials and Methods: The K. pneumoniae isolates were identified by biochemical tests and confirmed by genotyping. The modified Hodge test (MHT) was performed to detect carbapenemases, and antimicrobial susceptibility was determined for all isolates by the disc diffusion method. Also, for MHT-positive isolates, supposed to carbapenemases isolates, broth microdilution method was used to measure the minimum inhibitory concentrations (MICs) of meropenem and colistin. Results: The bla KPC genotypic evaluation revealed that only 5 of 96 isolates carried bla genes. Antimicrobial pattern showed that isolates carrying bla were resistant to cefepime, ticarcillin/tazobactam, and aztreonam discs. Also, results of broth microdilution method showed that KPC-producing K. pneumoniae was resistant to meropenem and colistin, according to the CLSI and EUCAST. Conclusion: In this study nearly half the isolates showed carbapenemase activity as shown by MHT results, but only few of them were carrying bla . Thus bla gene is not the main cause of resistance spread to carbapenems in Isfahan, Iran.

scholarly journals In VitroAntistaphylococcal Effects ofEmbelia schimperiExtracts and Their Component Embelin with Oxacillin and Tetracycline

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Johana Rondevaldova ◽  
Olga Leuner ◽  
Alemtshay Teka ◽  
Ermias Lulekal ◽  
Jaroslav Havlik ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medicinal Plants ◽  
Bacterial Infections ◽  
Inhibitory Concentration ◽  
Developed Countries ◽  
Positive Interactions ◽  
Fractional Inhibitory Concentration ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

Bacterial infections are in less-developed countries traditionally treated by remedies prepared from medicinal plants.Embelia schimperi(Vatke) is a plant used as a taenicide or disinfectant in Ethiopia, very often taken mixed with another plant species. In the present study, we examined two extracts prepared from seeds and twigs with leaves ofE. schimperiand its main present secondary metabolite embelin for their antibacterial combinatory effect with oxacillin and tetracycline against sensitive and resistantStaphylococcus aureusstrains. Minimum inhibitory concentrations were determined through the broth microdilution method, whereas the combinatory effect was evaluated through fractional inhibitory concentration sum (ΣFIC) indices. Results show many positive interactions and synergy occurring in embelin and oxacillin combinations against 4 out of 9 strains (ΣFIC 0.203–0.477) and for embelin and tetracycline combination against 3 out of 9 strains (ΣFIC 0.400–0.496). Moreover, the resistance to oxacillin has been overcome in 2 strains and to tetracycline in 3 strains. According to our knowledge, this is the first study showing antimicrobial combinatory effect ofE. schimperias well as of embelin. These findings can be used for the further research targeted on the development of new antistaphylococcal agents.

scholarly journals In Vitro Interaction of Caspofungin Acetate with Voriconazole against Clinical Isolates of Aspergillus spp

2002 ◽  
Vol 46 (9) ◽  
pp. 3039-3041 ◽  
Author(s):  
Sofia Perea ◽  
Gloria Gonzalez ◽  
Annette W. Fothergill ◽  
William R. Kirkpatrick ◽  
Michael G. Rinaldi ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Fractional Inhibitory Concentration ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
In Vitro Interaction ◽  
Vitro Data ◽  
In Vitro Data

ABSTRACT The interaction between caspofungin acetate and voriconazole was studied in vitro by using 48 clinical Aspergillus spp. isolates obtained from patients with invasive aspergillosis. MICs were determined by the NCCLS broth microdilution method. Synergy, defined as a fractional inhibitory concentration (FIC) index of <1, was detected in 87.5% of the interactions; an additive effect, defined as an FIC index of 1.0, was observed in 4.2% of the interactions; and a subadditive effect, defined as an FIC index of 1.0 to 2.0, was found in 8.3% of the interactions. No antagonism was observed. Animal models are required to validate the in vivo significance of these in vitro data presented for the combination of caspofungin and voriconazole.

scholarly journals Screening of the antimicrobial activity of marine sponge extracts from Martinique

2021 ◽  
Author(s):  
Julie Piron ◽  
Jessica Pastour ◽  
Niklas Tysklind ◽  
Juliette Smith-Ravin ◽  
Fabienne Priam
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Marine Sponges ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Bacterial Strains ◽  
Disc Diffusion Method ◽  
Staphylococcus Saprophyticus

AbstractMarine sponges are known for their antimicrobial, antifungal, and cytotoxic activity. In this study, the activity of aqueous and ethanoic extracts of 3 sponges from Martinique were tested on 5 bacterial strains: Bascillus cereus (CIP 783), Echerichia coli (CIP 54127), Pseudomonas aeruginosa (CIP A22), Staphylococcus aureus (CIP 67.8) and Staphylococcus saprophyticus (CIP 76125). The antimicrobial activity of Agelas clathrodes, Desmapsamma anchorata, and Verongula rigida, was demonstrated using the disc diffusion method and by determining the minimum inhibitory concentration and the minimum bactericidal concentration. The ethanoic extract of Agelas clathrodes had an inhibitory activity specifically on Staphylococcus aureus and Staphylococcus saprophyticus. No activity was observed for the other extracts. Further chemical analyses will be carried out in order to identify the active molecules of these sponges.

scholarly journals Determination of antibiotic resistance and minimum inhibitory concentration of meropenem and imipenem growth in Klebsiella strains isolated from urinary tract infection in Shahrekord educational hospitals

2019 ◽  
Vol 21 (2) ◽  
pp. 80-85
Author(s):  
Farshad Kakian ◽  
Behnam Zamzad ◽  
Abolfazl Gholipour ◽  
Kiarash Zamanzad
Keyword(s):  
Antibiotic Resistance ◽  
Urinary Tract ◽  
Minimum Inhibitory Concentration ◽  
Bacterial Infections ◽  
Inhibitory Concentration ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Accurate Identification ◽  
Tract Infections

Background and aims: Klebsiella is an opportunistic organism that is the cause of severe diseases such as pneumonia, septicemia, and urinary tract infections (UTIs). In addition, high antibiotic resistance has challenged the treatment of this bacterium. However, carbapenem antibiotics are considered as the therapeutic agents for selecting the treatment of penicillin- and cephalosporin-resistant gram-negative bacterial infections. The present study aimed to determine the resistance and minimum inhibitory concentration (MIC) of meropenem and imipenem. Methods: A total of 80 Klebsiella spp isolated from UTIs were collected in various educational wards (i.e., urology, obstetrics, and gynecology, as well as the units of infectious diseases, internal medicine, and intensive care) in different hospitals of Shahrekord. The isolates were then identified by using biochemical tests. Further, disc diffusion method was employed to determine the antibiotic resistance. Furthermore, MIC was estimated by the Epsilon-test strip. Moreover, P=Q=0.50, an error of 0.05, and an accuracy of 0.11 were considered for determining the sample size (n=80). Results: Based on the results of disc diffusion method, 24 strains were resistant to meropenem and imipenem. Additionally, the MIC was 24 (30%) by the E-test. In addition, 24 isolates had a MIC of ≥4 μg/mL for meropenem and imipenem and thus were resistant while 18 isolates were found to have a MIC of 1≤ MIC<4 μg/mL and therefore, were considered semi-sensitive (P<0.001). Conclusion: In general, Klebsiella strains were found to be resistant to meropenem and imipenem. Therefore, rapid and accurate identification of these strains and the selection of appropriate antibiotics can help quickly eradicate the infections caused by these bacteria. Accordingly, a waste of time, the consumption of medication, or even an increased resistance are prevented.

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 Antimicrobial Activity of Selected Essential Oils against Bacteria Isolated from Freshwater Fish

2021 ◽  
Vol 5 (1) ◽  
pp. 1-11
Author(s):  
Miroslava Kačániová ◽  
Alīna Klūga ◽  
Margarita Terentjeva ◽  
Simona Kunová ◽  
Katarína Rovná ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Enterococcus Faecium ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Yersinia Ruckeri ◽  
Disc Diffusion Method ◽  
Delftia Acidovorans ◽  
Litsea Cubeba ◽  
Microdilution Method

Abstract The aim of study was to determine the antimicrobial activity of ten essential oils against ten microorganisms isolated from fish. The following essential oils were tested: Cymbopogon nardus Rendle, Citrus limon, Leptospermum petersonii Bailey, Gaultheria procumbens, Pelargonium graveolens, Citrus paradisi, Citrus aurantifolia, Litsea cubeba Pers., Citrus reticulata Blanko, Vetiveria zizanoides. The disc diffusion method and microdilution method were used for determination of antimicrobial activity. Rhodotorula spp., Aerococcus spp., Aerococcus viridans, Enterococcus faecium, Enterococcus moraviensis, Aeromonas spp., Delftia acidovorans, Pseudomonas gessardii, Yersinia spp., Yersinia ruckeri, Yersinia enterocolitica were tested in the present study. The best antimicrobial activity of Leptospermum petersonii Bailey were found against Aerococcus spp., Enterococcus faecium, E. moraviensis, Delftia acidovorans, Pseudomonas gessardii, Yersinia ruckeri and Y. enterocolitica. Litsea cubeba Pers. was effective against Delftia acidovorans, Yersinia enterocolitica, Enterococcus faecium using the disc diffusion method. The best minimal inhibition concentration (MIC 50 - 1.5 µL/mL resp. MIC 90 - 1.6 µL/mL) was found for Litsea cubeba Pers. against Aerococcus spp. and Yersinia spp. using microdilution method.

scholarly journals Validation of a method of broth microdilution for the determination of antibacterial activity of essential oils

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Vanegas David ◽  
Abril-Novillo Andrea ◽  
Khachatryan Aleksandr ◽  
Jerves-Andrade Lourdes ◽  
Peñaherrera Eugenia ◽  
...  
Keyword(s):  
Essential Oils ◽  
Sensitivity And Specificity ◽  
Inhibitory Concentration ◽  
Tween 80 ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Continuous Contact ◽  
Microdilution Method ◽  
Broth Microdilution Method

Abstract Objective The aim of the present study was to adapt and optimize a broth microdilution method and compare it to the agar dilution method for the evaluation of activity of essential oils from medicinal plants against Gram-negative bacteria. Based on bibliographic research, active and not active oils were selected. The sensitivity and specificity were established as parameters for validation. The comparison between both methods was made using contingency analysis tables, based on the observed frequencies. For both methods, the minimum inhibitory concentration was determined against Escherichiacoli strains, in an essential oil concentration range between 0.03 and 0.48% (v/v). Results A stable emulsion formation was achieved with the addition of Tween 80 and constant agitation, guaranteeing the continuous contact of oil with bacteria (critical step in the microdilution method). The statistical analysis of results obtained with both methods presented a good sensitivity and specificity (100% in both cases), which let us correctly discriminate between active and non-active oils. The values obtained for the minimal inhibitory concentration were independent of the technique used. Finally, the obtained results show that the validated microtechnique allows important diminishment of time and resources for investigations dealing with essential oils or lipophilic extracts evaluation.

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