scholarly journals In vitro Antibacterial Activity of Manilkara hexandra (Sapotaceae) Seed Extracts and Violacein against Multidrug Resistant Streptococcus mutans

2015 ◽  
Vol 15 (1) ◽  
pp. 1 ◽  
Author(s):  
Krishna Patel ◽  
Arwa Kaizer Ali ◽  
Nishith Nair ◽  
Vijay Kothari

Extracts of the Pongamia pinnata, Manilkara hexandra, and Pyrus pyrifolia seeds prepared by microwave assisted extraction method, and the violet pigment- violacein extracted from Chromobacterium violaceoum were screened for their antibacterial activity against Streptococcus mutans.M. hexandra extracts were able to inhibit both the test strains of S. mutans used in this study with minimum inhibitory concentration (MIC) ranging from 600-800 µg/mL. These extracts exerted bactericidal action against S. mutans with minimum bactericidal concentration (MBC) of 600-900 µg/mL. Acetone extract of M. hexandra seeds registered highest average total activity of 231.20 mL/g. Extraction efficiency was found to have a moderately good correlation with antibacterial activity. Violacein exerted bactericidal action with MIC and MBC of less than 2 µg/mL against both the strains.

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.


Author(s):  
Yucheng Cao ◽  
Kaiyi Wang ◽  
Jiali Wang ◽  
Haoran Cheng ◽  
Mengxin Ma ◽  
...  

Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36–39 exhibited potent antibacterial activity against hospital-acquired MRSA, with MIC = 8–64 μg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S314-S314
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Tarun Mathur ◽  
Ian Morrissey

Abstract Background The incidence of infections caused by multidrug-resistant Acinetobacter baumannii is increasing at an alarming rate in Southeast Asia and other parts of the world. Sulbactam (SUL) has intrinsic antibacterial activity against A. baumannii; however, the prevalence of β-lactamases in this species has limited its therapeutic use. Durlobactam (ETX2514, DUR) is a novel β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C and D β-lactamases. DUR restores SUL in vitro activity against multidrug-resistant A. baumannii. Against >3,600 globally diverse, clinical isolates from 2012–2017, addition of 4 mg/L DUR reduced the SUL MIC90 from >32 to 2 mg/L. SUL-DUR is currently in Phase 3 clinical development for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.The goal of this study was to determine the activity of SUL-DUR and comparator antibiotics (amikacin (AMK), ampicillin-sulbactam (AMP-SUL), cefoperazone-sulbactam (CFP-SUL) and meropenem (MEM)) against A. baumannii isolated from hospitalized patients in India. Methods A total of 121 clinical A. baumannii isolates from multiple hospital settings and infection sources were collected between 2016–2019 from six geographically diverse hospitals in India. Species identification was performed by MALDI-TOF. Susceptibility of these isolates to SUL-DUR (10µg/10µg) and comparator antibiotics was determined by disk diffusion using CLSI methodology and interpretive criteria, except for CFP-SUL, for which resistance was defined using breakpoints from the CFP-SUL package insert. Results As shown in Table 1, resistance of this collection of isolates to marketed agents was extremely high. In contrast, based on preliminary breakpoint criteria, only 11.5% of isolates were resistant to SUL-DUR. Conclusion The in vitro antibacterial activity of SUL-DUR was significantly more potent than comparator agents against multidrug-resistant A. baumannii isolates collected from diverse sites in India. These data support the continued development of SUL-DUR for the treatment of antibiotic-resistant infections caused by A. baumannii. Disclosures All authors: No reported disclosures.


Author(s):  
Na Li ◽  
Jiang-Kun Dai ◽  
Dan Liu ◽  
Jin-Yi Wang ◽  
Jun-Ru Wang

Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure–activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.


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