Determination of minimum inhibitory concentration (MIC) of cloxacillin for selected isolates of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) with their antibiogram

The minimum inhibitory concentration (MIC) represents the concentration of antimicrobial at which there is complete inhibition of growth of organism. In order to determine the MIC of cloxacillin, 10 MRSA were previously detected from 40 clinical isolates of Staphylococcus aureus by polymerase chain reaction (PCR). Agar plate dilution test was used to determine the MIC of cloxacillin. The clinical samples were collected from Mymensingh Medical College Hospital, Mymensingh. The study was done in the Department of Medicine, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh from July 2006 to June 2007. The MIC of the cloxacillin for 5 MRSA strains were â¥32 (mg/ml), for 1 MRSA strain was â¥ 128(mg/ml) and for another 4 MRSA strains were above â¥128 (mg/ml). Antimicrobial susceptibility test of the isolated organisms were done by disc diffusion method. On antibiotic susceptibility test, MRSA strains showed 100% resistant against penicillin, oxacillin, cloxacillin and amoxycillin. Cent per cent susceptibility of MRSA was found against vancomycin, ciprofloxacin, erythromycin, fusidic acid and rifampicin. Key words: Minimum inhibitory concentration (MIC), antibiotic resistance, cloxacillin, methicillin-resistant Staphylococcus aureus (MRSA) DOI = 10.3329/bjvm.v6i1.1350 Bangl. J. Vet. Med. (2008). 6 (1): 121-126

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Synthesis and Antimicrobial Studies of Coumarin-Substituted Pyrazole Derivatives as Potent Anti-Staphylococcus aureus Agents

Molecules ◽

10.3390/molecules25122758 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2758 ◽

Cited By ~ 3

Author(s):

Rawan Alnufaie ◽

Hansa Raj KC ◽

Nickolas Alsup ◽

Jedidiah Whitt ◽

Steven Andrew Chambers ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Minimum Inhibitory Concentration ◽

Methicillin Resistant Staphylococcus Aureus ◽

Inhibitory Concentration ◽

Fatality Rate ◽

Pyrazole Derivatives ◽

Methicillin Resistant ◽

Antimicrobial Studies ◽

Mrsa Strains

In this paper, synthesis and antimicrobial studies of 31 novel coumarin-substituted pyrazole derivatives are reported. Some of these compounds have shown potent activity against methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) as low as 3.125 µg/mL. These molecules are equally potent at inhibiting the development of MRSA biofilm and the destruction of preformed biofilm. These results are very significant as MRSA strains have emerged as one of the most menacing pathogens of humans and this bacterium is bypassing HIV in terms of fatality rate.

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Phenotypic study of Macrolide-Lincosamide-Streptogramin B Resistance in Staphylococcus aureus and their relationship with Methicillin-Resistant Staphylococcus aureus (MRSA) at Tertiary Care in Eastern Nepal

Journal of Nobel Medical College ◽

10.3126/jonmc.v5i1.15745 ◽

2016 ◽

Vol 5 (1) ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Ganesh Kumar Singh ◽

Bigu Kumar Chaudhari ◽

Kamal Prasad Parajuli

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Tertiary Care ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Constitutive Resistance ◽

Antibiotic Susceptibility Test

Background Resistance to antimicrobial agents is prevalent among Staphylococci. This has led to wide uses of macrolide-lincosamide-streptogramin B (MLSB) antibiotics to Staphylococcus aureus (S. aureus) infections. MLSB though chemically distinct, have similar target site and mode of action. The multiple mechanisms are responsible for resistance to MLSB antibiotics which can lead to clinical failure. The aim of the study was to investigate the frequency of inducible and constitutive clindamycin resistance among clinical isolates of S. aureus and their relationship with Methicillin-resistant Staphylococcus aureus (MRSA).Material & Methods A total of 336 unique Staphylococcus aureus isolates from different clinical samples obtained from patients were studied. Antibiotic susceptibility test was performed by Kirby- Bauer disc diffusion method. “D test” was performed to detect inducible clindamycin resistance as per CLSI guidelines. MRSA was detected using Cefoxitin (30μg) and results were interpreted according to CLSI criteria.Results Inducible clindamycin resistance was seen in 45 (13.39%), constitutive clindamycin resistance was seen among 58 (17.26%) while MS phenotype was observed among 38(11.30%) of isolates. Inducible resistance as well as constitutive resistance was higher among MRSA as compared to MSSA (21.11%, 4.48% and 21.11%, 12.82%respectively).Conclusion The Successful use of clindamycin for the treatment of infection caused by S. aureus can be predicted based on the result of simple and inexpensive D test.Journal of Nobel Medical CollegeVolume 5, Number 1, Issue 8, January-July 2016, 1-5

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Evaluation of Antimicrobial Effect of Oenothera biennis by Using Different Concentrations of Extract against Staphylococcus Aureus -An experimental study

10.53350/pjmhs211592900 ◽

2021 ◽

Vol 15 (9) ◽

pp. 2900-2902

Author(s):

Anila errum ◽

M. Talha zahid ◽

Saima pervaiz ◽

Faiza ishtiaq ◽

Nada imran ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Minimum Inhibitory Concentration ◽

Methicillin Resistant Staphylococcus Aureus ◽

Inhibitory Concentration ◽

Antimicrobial Effect ◽

Seed Extract ◽

Diffusion Method ◽

Microbiology Laboratory ◽

Oenothera Biennis ◽

Methicillin Resistant

Background: Staphylococcus aureus is a superbug which is infamous for causing wound infections. Unfortunately it is developing resistance quickly against commonly used antibiotics. Antimicrobial drugs effective against methicillin resistant staphylococcus aureus are too expensive to afford by impoverish population in our country. However, herbal medicines are seen to be equally effective with less severe adverse effects. There is need to explore alternative medicines of botanical origin to cure dangerous bacteria. Oenothera biennis contains phytochemicals which have antimicrobial activity against some gram negative and gram positive microorganisms. Objectives: To evaluate the minimum inhibitory concentration of Oenothera biennis seed extract against staphylococcus aureus by using different concentrations. Study Design: In Vitro antibacterial study. Settings: The study was conducted in microbiology laboratory of Shaikh Zayed Medical Complex, Lahore. Duration: One year. Methodology: Oenothera biennis extract was prepared in 95% Ethanol in biochemistry laboratory of Pakistan Council of Scientific and Industrial Research (PCSIR) Lahore. Staphylococcus aureus isolates were procured from microbiology laboratory and American Type Culture Collection (ATCC) strains used as quality control for MSSA & MRSA, were purchased from musaji adam and sons Karachi ([email protected]). The antibacterial activity of oenothera biennis seed extract against staphylococcus aureus was tested by deep well broth microdilution and disc diffusion method. Different concentrations of stock solutions (100μg/10μl to 500μg/10μl of DMSO) were used to test antimicrobial effect to establish dose response relationship. Results: Results were measured and compared according to Clinical and Laboratory Standard Institute. Oenothera biennis seed extract inhibited growth of methicillin sensitive and methicillin resistant staphylococcus aureus isolate from laboratory as well as ATCC strains with minimum inhibitory concentration 530μg/10μl solvent. Whereas other concentrations 50 μg/10μl ,100 μg/10μl ,150 μg/10μl ,200 μg/10μl ,250 μg/10μl ,300 μg/10μl ,350 μg/10μl ,400 μg/10μl ,450 μg/10μl and 500 μg/10μl had no effect at all. Conclusion: Oenothera biennis extract inhibits growth of staphylococcus aureus at concentration of 530μg remarkably. This can inhibit both MSSA & MRSA already proved in our study. This could be beneficial as an alternate medicine. However, further research is needed to be conducted for animal study. Key words: Oenothera biennis, ethanolic extract, Methicillin sensitive, Methicillin Resistant Staphylococcus aureus, MSSA, MRSA.

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Monitoring of multiresistant community-associated MRSA strains from patients with pathological processes of different localization

Regulatory Mechanisms in Biosystems ◽

10.15421/021841 ◽

2018 ◽

Vol 9 (2) ◽

pp. 281-286

Author(s):

T. V. Sklyar ◽

K. V. Lavrentievа ◽

V. G. Gavrilyuk ◽

N. V. Kurahina ◽

M. O. Vereshchaha ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Nasal Cavity ◽

Fusidic Acid ◽

Threshold Value ◽

Urine Samples ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Vancomycin Resistant ◽

Mrsa Strains

The therapy of infections, caused by methicillin-resistant Staphylococcus aureus (MRSA) with multiple resistance to antibiotics remains one of the most acute problems all over the world. It is all the more complicated since a priori the MSRA strains are not sensitive to the group of β-lactam antibiotics and multiresistant isolates are resistant to other groups of antimicrobial preparations, including antibiotics of choice (rifampicin, vancomycin, fusidic acid, co-trimoxazole and linezolid). From the samples of biomaterials of patients with pathological processes of different localization, we isolated 335 strains of bacteria, which were identified as Staphylococcus aureus, 169 (50.4%) of which were methicillin-resistant variants: 57.5% cultures were isolated from the nasal discharge; 50.7% – from faeces at intestinal dysbioses; by 40.0% – from conjunctival discharge, pharyngeal swab, outer ear swab and sputum; 33.3% – from urine samples. Antibiotic susceptibility of the isolated cultures was estimated by the disc-diffusion method and the method of serial dilution. The MRSA strains appeared to be most resistant to gentamycin, erythromycin (by 59.5% of cultures) and ciprofloxacin (53.3% of isolates), most sensitive – to vancomycin, co-trimoxazole and fusidic acid. The frequency of isolation of the cultures that are resistant to antibiotics did not exceed 4.1%. Rifampicin suppressed the growth of 75.8% and linezolid – of 100.0% of strains. Depending on the kind of biomaterial taken, MRSA strains, isolated from the nasal cavity, outer ear, urine samples, samples of sputum and faeces at intestinal dysbioses proved to be most resistant to the tested antimicrobial preparations. Rifampicin- and vancomycin-resistant strains of methicillin-resistant staphylococci made up 21.3% of the total number of the detected MRSA. They were most often isolated from the clinical samples taken from the nasal cavity and faeces. When determining minimal inhibitory concentration (MIC) of rifampicin and vancomycin, which are antibiotics of choice for treatment of infections caused by multiresistant MRSA, it was found that for 55.5% of the MRSA strains isolated from faeces, MIC of rifampicin coincided with the threshold value for this antibiotic and for 44.5%, it exceeded the threshold value by 2 times (4 µg/ml). 22.2% of them were characterized by the critical value of susceptibility to vancomycin (MIC ≥ 2 µg/ml). From rifampicin- and vancomycin-resistant MRSA stains, isolated from the nasal cavity, MIC of rifampicin coincided with the threshold value for this antibiotic for 66.7% of cultures, and exceeded it at least by 2 times for 33.3%. 11.1% of them were characterized by the critical level of susceptibility to vancomycin (MIC ≥ 2 µg/ml) and by 3.7% of strains exceeded MIC by 2 and 4 times respectively (4 and 8 µg/ml).

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