scholarly journals In-vitro synergistic antibacterial effect of atorvastatin and ampicillin against resistant Staphylococcus spp and E.coli isolated from bovine mastitis

2019 ◽  
Author(s):  
Sriraam Sankar ◽  
Ramasamy Thangamalai ◽  
Sriram Padmanaban ◽  
Porteen Kannan ◽  
M R Srinivasan ◽  
...  

AbstractThe colossal rise in antimicrobial resistance has led to treatment failures and so mastitis has become cumbersome to treat. The objective of this study was to evaluate the antibacterial effect of non-antibiotic drug, atorvastatin in combination with antimicrobial, ampicillin against two commonly isolated bacterial species Staphylococcus spp and E. coli from bovine mastitis. Milk samples were collected from mastitis cows, visiting Veterinary Clinical Complex. Bacterial isolation was performed using Eosin Methylene Blue (EMB) agar and Mannitol Salt Agar (MSA), followed by characterization and identification by biochemical tests and gram staining. Genotypic confirmation was done by Polymerase Chain Reaction (PCR) with subsequent screening for resistant genes-mec A, blaTEM. Antibiotic Sensitivity Test (ABST) of the isolates against 12 different antimicrobials, atorvastatin only, and combination of atorvastatin with ampicillin were performed using Kirby-Bauer disc diffusion method. Minimum Inhibitory Concentration (MIC) of ampicillin alone and ampicillin in combination with atorvastatin were determined by modified microdilution method. Staphylococcus spp (77.5%) and E.coli (35%) were the two major pathogens isolated in the current study and multi-drug resistance was observed. Among the antimicrobials, the ampicillin showed 100% resistance against Staphylococcus spp and 85.71% resistance against E. coli. Atorvastatin did not display antibacterial effect as a sole agent but displayed synergistic antibacterial activity with ampicillin. There was an average increase in Minimum Inhibitory Concentration of ampicillin for E.coli and Staphylococcus spp isolates and atorvastatin decreased the Minimum Inhibitory Concentration of ampicillin in combination. The ampicillin shows more resistance against both Staphylococcus spp and E.coli, while atorvastatin improves the effect of ampicillin in-vitro. So, atorvastatin may be combined with ampicillin for the treatment of Gram-positive and Gram-negative infections. However, further studies are required to ascertain the exact mechanism of action of atorvastatin with respect to their antibacterial effect for them to be redeployed as an antimicrobial drug in the future.

2018 ◽  
Vol 20 (87) ◽  
pp. 65-69
Author(s):  
R.A. Peleno

The data of the influence of active substances of anthelmintic and antiprotozoal preparations on the growth of L. casei IMB B-7280 and E. coli 055K59 are provided in the article. Their minimal inhibitory concentrations were determined for these strains of microorganisms and the active substances with which possible simultaneous application of probiotic strain L. casei IMB В-7280 is established. With this aim, the effect on the growth of L. casei IMB B-7280 and E. coli 055K59 and the minimum inhibitory concentration of fenbendazole, levamisole and ivermectin, which are part of the anthelmintic preparations and amprolium, tylosin, sodium sulfadimexone and sodium sulfatyazole, which are active substances of antiprotozoal drugs, were investigated. The determination of the minimum inhibitory concentration of the active substances of antiparasitic agents against these strains of microorganisms was carried out in in vitro experiments by serial dilutions in a dense MRS environment and MPA, and a study of the effect on the growth by diffusion method, followed by measurement of growth retardation zones in millimeters. It is established that among active substances of anthelmintic preparations only phenbendazole caused growth retardation and only relative to L. casei IMB B-7280. Among the active substances of antiprotozoal drugs, sodium sulfatyazole was the most active, which inhibited growth as L. casei IMB-7280 and E. coli 055K59 № 3912/41. Thylosin was effective only in relation to L. casei IMB B-7280 and at the highest concentration of 0.03%, the growth retardation zone was 23.4 ± 0.92 mm. Sodium sulfadimetoxin caused the growth retardation of L. сasei IMB В-7280 only at the highest concentration. The minimum inhibitory concentration of active substances of anti-parasitic drugs was different for strains L. casei IMB B-7280 and E. coli 055K59 № 3912/4. The strongest inhibitory effect was shown by tylosin, which stopped the growth of L. casei IMB B-7280 and E. coli 055K59 № 3912/41 respectively at concentrations of 0.00125 and 50.0 mg/ml. Active substances such as amprolium, levamisole and ivermectin did not significantly inhibit the growth of L. casei, IMB B-7280 and E. coli 055K59 № 3912/41, since their minimal inhibitory concentration was in the range of 4000 to 6000 mg ml.


2020 ◽  
Vol 42 (1) ◽  
pp. 120-120
Author(s):  
Nazia Gulzar Nazia Gulzar ◽  
Saiqa Andleeb Saiqa Andleeb ◽  
Shaukat Ali Shaukat Ali ◽  
Sadia Nazer Sadia Nazer ◽  
Tariq Iqbal Muhammad Abdul Rauf Khan and Abida Raza Tariq Iqbal Muhammad Abdul Rauf Khan and Abida Raza

The aim of study is to develop the economic plant-based antibacterial agents to improve the treatment strategies for bacterial infections at nano-scale. In current research silver nanostructures synthesis was carried out using Trillium govanianum aqueous extract. Characterizations were done using UV–Visible spectrophotometer, scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Antibacterial efficacy of green-synthesized silver nanostructures and aqueous extract was evaluated via agar well diffusion method, crystal violet assay (antibiofilm analysis), tetrazolium salt assay (cell viability assay), Direct agar overlay technique, and TLC- spot screening against clinical bacterial pathogens. Synergistic effect of synthesized nanostructures, aqueous extract along with antibiotics was determined by agar disc diffusion method. Minimum inhibitory concentration was also evaluated using agar well diffusion method. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used for screening of antioxidant potential effect at various concentrations (0.5, 1 and 1.5 and#181;l). The indication of major phytochemical constituents was determined using both qualitative methods and Thin Layer Chromatography (TLC). Absorbance in UV region (295 nm) corresponds to the out of plane quadrupole Plasmon-resonance while at 350 nm corresponds to in-plane dipole resonance. SEM images shows prepared the morphology of Ag nanostructures TGAgNSs is not exactly spherical while XRD analysis shows that highly crystalline TGAgNSs have been prepared with average crystallite size of 27.94 nm. The FTIR spectrum represents sharp peaks of aldehyde, amide I, aromatic rings, and polysaccharides. Minimum inhibitory concentration showed the increased bactericidal effect with increase in concentration of silver nanostructures. Maximum inhibition of E. coli, S. epidermidis, S. pyogenes, and K. pneumonia was recorded at 0.12 mg/ml concentration of TGAgNSs with 7.6.0and#177;0.0 mm, 7.6and#177;0.0 mm, 6.6and#177;0.0 mm, and 7.0and#177;0.0 mm zones of inhibition. Similarly, TGAgNSs showed maximum inhibition of E. coli, S. pyogenes, and S. marcesscens at 0.14 mg/ml concentration (8.3and#177;0.0 mm, 7.0and#177;0.0 mm, 7.0and#177;0.0 mm), respectively. Cell viability, antibiofilm assay, TLC-spot screening, and TLC-bio-autography proves the potential antibacterial effect of TGAgNSs. Synergistic effect showed greater antibacterial effect. Glycosides, saponins, flavonoids, proteins, terpenoids, alkaloids, phenols, and tannins were detected. The scavenging potential of TGAgNSs was calculated as 74% at 1.5 and#181;l. It was concluded that green synthesized nanostructures have efficient antibacterial potential and would be used in medical devices to cure infections in near future.


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.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Awol Mekonnen ◽  
Berhanu Yitayew ◽  
Alemnesh Tesema ◽  
Solomon Taddese

In this study, thein vitroantimicrobial activities of four plant essential oils (T. schimperi,E. globulus,R. officinalis, andM. Chamomilla) were evaluated against bacteria and fungi. The studies were carried out using agar diffusion method for screening the most effective essential oils and agar dilution to determine minimum inhibitory concentration of the essential oils. Results of this study revealed that essential oils ofT. schimperi,E. globulus, andR. officinaliswere active against bacteria and some fungi. The antimicrobial effect ofM. chamomillawas found to be weaker and did not show any antimicrobial activity. The minimum inhibitory concentration values ofT. schimperiwere<15.75 mg/mL for most of the bacteria and fungi used in this study. The minimum inhibitory concentration values of the other essential oils were in the range of 15.75–36.33 mg/mL against tested bacteria. This study highlighted the antimicrobial activity of the essential oil ofE. globulus,M. chamomilla,T. Schimperi, andR. officinalis. The results indicated thatT. schimperihave shown strong antimicrobial activity which could be potential candidates for preparation of antimicrobial drug preparation.


2020 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
Bendella Amina nor elhouda ◽  
Ghazi Kheira ◽  
Meliani Samia

AbstractThe aim of this study is to test two different methods for evaluating the in vitro antibacterial effect of Thymus fontanesii Boiss. et Reut. essential oil against standard and clinical bacterial strains responsible for bovine mastitis: the disc diffusion method or the aromatogram which allows the demonstration of the antibacterial power of essential oils on the bacterial strains tested, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and two strains isolated from bovine mastitis milk S. aureus and E. coli. The inhibition activity of the essential oil of T. fontanesii on bacterial strains by the two methods shows that the antimicrobial power of this oil is very important and is characterized by bactericidal and bacteriostatic action against gram negative and gram positive bacteria. The antimicrobial evaluation by the aromatogram showed good antibacterial activity against all the strains tested, the zones of inhibition of the bacteria were between 23,33±1,527mm and 37,5±3,535 mm. The search for minimum inhibitory concentrations MIC and bactericides CMB made it possible to quantitatively assess the antimicrobial power of this essential oil. In this work, the MIC was 0,625 µl/ml for all strains tested, and the lowest CMB was that of T. fontanesii against E. coli ATCC 25922 was 0,625 µl/ml.


Extracts from many types of plants show several evidences of beneficial health effects in the living system. Calendula officinalis is a well known medicinal plant in our country. The purpose of this study was to examine the effectiveness of C. officinalis for control of growth and survival of microorganisms. Inhibition of growth was tested by the paper disc agar diffusion method. Minimum inhibitory concentration (MIC) was determined by the tube dilution method. C. officinalis leaf extract showed inhibition (MIC, inhibitory) to Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis and to the other bacteria tested. Antimicrobial effects of leaf extract of C. officinalis on some microorganisms including pathogens were investigated. The extract of C. officinalis leaf which is prepared in was tested on bacterial cultures such as B. subtilis, S. lutea, E. coli, K. pneumoniae and also investigated that minimum inhibitory concentration 4µg/ml of leaf extract of C. officinalis in Petroleum ether against K. pneumoniae and largest inhibitory zone are created by 512mg/ml chloroform extract against E. coli leaf extract of C. officinalis in Petroleum ether has proved better for antibacterial activity. This study demonstrates that the potentiality of C. officinalis as a source of antimicrobials that could be harness for use in the health care delivery process.


2015 ◽  
Vol 43 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Mihaela NICULAE ◽  
Laura STAN ◽  
Emoke PALL ◽  
Anamaria Ioana PAȘTIU ◽  
Iulia Maria BALACI ◽  
...  

The study was aimed to characterize the chemical composition and the antimicrobial activity of Romanian propolis ethanolic extracts (EEP) against antibiotic-sensitive and antibiotic-resistant E. coli strains isolated from bovine mastitis. The preliminary antimicrobial screening was performed by a disk diffusion method, followed by determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) based on broth microdilution assay; further, the synergistic action of propolis with antimicrobial drugs was assessed by a disk diffusion method on agar containing subinhibitory concentrations of propolis. For the chemical characterisation of EEP, the flavonoids (flavones/flavonols, flavanones/dihydroflavonols) and total phenolics were evaluated by spectrophotometric methods. The phenolic compounds of these extracts were also determined using HPLC. The results indicated for Romanian propolis ethanolic extracts the typical poplar composition profile with flavonoids and phenolic acids as main biological active compounds, with chromatographic analysis data confirmed also spectrophotometrically. In addition, positively correlated with the chemical composition, a strong antimicrobial efficacy was exhibited towards E. coli strains, along with interesting synergistic interaction with antibiotics that can be further investigated to obtain propolis-based formulation with antibacterial properties. Subsequent in vitro and in vivo studies evaluating the safety and efficacy are intended to consider propolis in veterinary therapeutic protocols.


2017 ◽  
Vol 10 (2) ◽  
pp. 131-135
Author(s):  
Ritika Malhotra ◽  
ND Shashikiran

ABSTRACT Aim The aim of the present in vitro study is to evaluate and compare antimicrobial efficacy of commercially available child's dental formulas in reduced concentrations containing different forms of fluoride against Streptococcus mutans activity. Materials and methods The selected dentifrices were prepared in dilutions of 1:1, 1:2, 1:4, 1:8, and 1:16 using sterile pyrogen-free distilled water. Various dilutions of the selected toothpaste slurries were incubated in the agar plate containing pure strains of S. mutans, and antimicrobial activity of each was assessed by measuring the diameter of zones of inhibition (in mm). Agar well plate diffusion method and minimum inhibitory concentration (MIC) determination were the methods used in this study. The inhibitory circle of each dentifrice was measured and MIC was achieved by considering the value of diameter of the circle. Results The results of the study showed that even at a lower concentration of fluoride, inhibition halos were obtained for all the formulations at different dilutions. Conclusion The kid's formulations having lower fluoride concentration show antimicrobial activity even after dilutions. Thus, commercially, the fluoride concentrations can be further lowered down in the dentifrices, thereby reducing the risk associated with fluoride. How to cite this article Malhotra R, Singla S, Shashikiran ND. Comparison of Antimicrobial Activity of Child Formula Dentifrices at different Concentrations: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):131-135.


Extracts from many types of plants show several evidences of beneficial health effects in the living system. Calendula officinalis is a well known medicinal plant in our country. The purpose of this study was to examine the effectiveness of C. officinalis for control of the growth and survival of microorganisms. The inhibition of growth was tested by the paper disc agar diffusion method. Minimum inhibitory concentration (MIC) was determined by the tube dilution method. C. officinalis leaf extract showed inhibition (MIC, inhibitory) to Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis and to the other bacteria tested. Antimicrobial effects of leaf extract of C. officinalis on some microorganisms including pathogens were investigated. The extract of C. officinalis leaf which is prepared in was tested on bacterial cultures such as B. subtilis, S. lutea, E. coli, K. pneumoniae and also investigated that minimum inhibitory concentration 4µg/ml of leaf extract of C. officinalis in petroleum ether against K. pneumoniae and largest inhibitory zone are created by 512mg/ml chloroform extract against E. coli leaf extract of C. officinalis in petroleum ether has proved better for antibacterial activity. This study demonstrates that the potentiality of C. officinalis as a source of antimicrobials that could be harness for use in the health care delivery process.


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