scholarly journals Antibacterial activity of human defensins against Staphylococcus aureus and Escherichia coli

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10455
Author(s):  
Albert Bolatchiev
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Synergistic Effects ◽  
Bacterial Strains ◽  
E Coli ◽  
Checkerboard Assay ◽  
Conventional Antibiotics ◽  
Human Defensins ◽  
Methods Of Treatment

Background The global problem of antibiotic resistance requires the search for and development of new methods of treatment. One of the promising strategies is the use of low doses of antimicrobial peptides, in particular, human defensins HNP-1, hBD-1, and hBD-3, in combination with antibacterial drugs already used in clinical practice. This approach may be used to increase the effectiveness of conventional antibiotics. However, this requires thorough study of the effectiveness of defensins in combination with antibiotics against a large number of bacterial strains with known phenotypes of antibiotic resistance. The aim of this work was to study the antibacterial effect of HNP-1, hBD-1 and hBD-3 in combination with rifampicin or amikacin against clinical isolates of Staphylococcus aureus (n = 27) and Escherichia coli (n = 24) collected from hospitalized patients. Methods The standard checkerboard assay was used to determine minimum inhibitory concentrations (MICs) of antimicrobials. The combined microbicidal effects of two substances (defensin + conventional antibiotic) were assessed by the fractional inhibitory concentration index (FICI). Results The highest anti-staphylococcal activity (including methicillin-resistant strains) among defensins was demonstrated by hBD-3 that had MIC of 1 (0.5–4) mg/L (hereinafter, MIC values are presented as median and interquartile range). The MIC of HNP-1 against S. aureus was 4 (2–8) mg/L; the MIC of hBD-1 was 8 (4–8) mg/L. Against E. coli, the most effective was also found to be hBD-3 that had MIC of 4 (4–8) mg/L; the MIC of HNP-1 was 12 (4–32) mg/L. The combinations of HNP-1 + rifampicin and hBD-3 + rifampicin demonstrated synergistic effects against S. aureus. Against E. coli, combinations of HNP-1 + amikacin and hBD-3 + amikacin also showed synergy of action.

scholarly journals IDENTIFICATION AND OCCURRENCE OF ANTIBIOTIC RESISTANCE OF Staphylococcus aureus AND Escherichia coli ISOLATED FROM RECREATIONAL PARKS AROUND KOTA KINABALU, SABAH

2020 ◽  
pp. 55
Author(s):  
Rajeena Sugumaran ◽  
Pamela David Jocksing ◽  
Nur Athirah Yusof
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Age Groups ◽  
Morphological Characteristics ◽  
Brain Heart Infusion ◽  
Asian Population ◽  
The Elderly ◽  
Bacterial Strains ◽  
E Coli

Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are contributors to infection cases among the Asian population. S. aureus is found in the mucous lining of noses and is mainly non-pathogenic while E. coli, mostly harmless bacteria, are found in the intestine. Pathogenic strains of both bacteria have adverse effects on the elderly and younger age group of the population. Samples were collected from recreational parks around Kota Kinabalu as they are hotspots frequently visited by families with both age groups. The bacterial samples were isolated and cultured on selective media such as Baird-Parker agar (BPA), Brain Heart Infusion (BHI) agar, MacConkey agar and Eosin-Methylene Blue (EMB) agar. Morphological characteristics of bacterial growth were observed, where S. aureus had black-shiny growth in BPAand E. coli had a metallic-green sheen in EMB agar. The suspected bacteria samples were then stained and viewed under a light microscope. S. aureus was identified as gram-positive, stained violet with a circular shape and clustered  appearance. E. coli was identified as gram-negative, stained red, rod-shaped with 2 – 3 bacterial alignment. Antibiotic resistance test resulted in S. aureus and E. coli samples did not display 100% resistance among 4 antibiotics tested (ampicillin, penicillin, tetracycline and chloramphenicol). Most of the bacteria samples were a minimum inhibitory of 0.1 mg/mL of antibiotic concentration. These results provide a foundation for further research on identifying bacterial strains using molecular methods. The findings can then be used to disseminate information to the public to create awareness of potential disease outbreaks in the city.

scholarly journals Antibacterial Activity of Geraniol in Combination with Standard Antibiotics against Staphylococcus aureus, Escherichia coli and Helicobacter pylori

2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Subrat Kumar Bhattamisra ◽  
Chew Hui Kuean ◽  
Lee Boon Chieh ◽  
Vivian Lee Yean Yan ◽  
Chin Koh Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Inhibitory Concentration ◽  
Therapeutic Potential ◽  
E Coli ◽  
Checkerboard Assay ◽  
H Pylori

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coli and Helicobacter pylori was tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coli and H. pylori was found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureus with FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pylori with the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti- H. pylori effect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pylori infection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureus and E.coli infection.

scholarly journals Utilization of Mn-Doped ZnSe/ZnS Core/Shell Quantum Dots for Rapid Detection of Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Thi-Diem Bui ◽  
Quang-Liem Nguyen ◽  
Thi-Bich Luong ◽  
Van Thuan Le ◽  
Van-Dat Doan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Fluorescent Labeling ◽  
Core Shell ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
E Coli ◽  
Mn Doped

In this study, Mn-doped ZnSe/ZnS core/shell quantum dots (CSQDs) were synthesized in aqueous solution using polyethylene glycol as a surface stabilizer and successfully applied in the detection of Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) for the first time. The CSQDs were conjugated with anti-E. coli antibody and anti-MRSA antibody via protein A supported by 1-ethyl-3-(-3-dimethylaminopropyl)carbodiimide hydrochloride for fluorescent labeling of the intact bacterial cells. The detection was performed for the bacterial strains cultivated in Luria-Bertani liquid medium. The obtained results indicate that E. coli O157:H7 and MRSA can be detected within 30 min at a high sensitivity of 101 CFU/mL. This labeling method based on the highly fluorescent CSQDs may have great potential for use in the food industry to check and prevent outbreaks of foodborne illness.

Note: Effect of Some Spice Extracts on Bacterial Inhibition

2003 ◽  
Vol 9 (5) ◽  
pp. 353-358 ◽  
Author(s):  
O. Sagdic ◽  
A. G. Karahan ◽  
M. Ozcan ◽  
G. Ozkan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Yersinia Enterocolitica ◽  
Inhibition Zone ◽  
Bacterial Strains ◽  
Inhibitory Effects ◽  
Antibacterial Effects ◽  
E Coli ◽  
Inhibition Zones ◽  
Mrs Broth

Eighteen extracts of spices commonly consumed worldwide and grown naturally in Turkey were tested against twenty three bacterial strains to compare their antibacterial effects with eleven antibiotics. Eight pathogens and fifteen lactobacilli isolated from chick intestine were used as the test microorganisms. Pathogens (six different Staphylococcus aureus strains, Escherichia coli ATCC 25922 and Yersinia enterocolitica ATCC 1501) were grown in Nutrient broth and lactobacilli in MRS broth. Hop extracts formed inhibition zones against S. aureus strains of upto 36 mm. Inhibitory effects of hop extracts against S. aureuswere generally higher than that of erythromycin as antibiotic. Helichrysum compactum extract produced an inhibition zone of 23mm to E. coli ATCC 25922 and 26mm to Y. enterocolitica ATCC 1501. Helichrysum compactum extract inhibited the growth of Y. enterocolitica ATCC 1501 more than other spice extracts. While inhibition zones of these extracts against lactobacilli were found smaller than on S. aureus strains, inhibition zones of the same extracts against lactobacilli were found similar to those of E. coli ATCC 25922 and Y. enterocolitica ATCC 1501.

scholarly journals Bacterial phagocytosis by macrophages from lipopolysaccharide responder and nonresponder mouse strains

1980 ◽  
Vol 28 (3) ◽  
pp. 762-765
Author(s):  
A Cuffini ◽  
N A Carlone ◽  
G Forni
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
The Other ◽  
Mouse Strains ◽  
Bacterial Strains ◽  
Phagocytic Capacity ◽  
Tumoricidal Activity ◽  
E Coli ◽  
Proteose Peptone ◽  
Lipopolysaccharide Endotoxin

The phagocytic capacity of macrophages from C3H/H3J mice was assessed against lipopolysaccharide-producing (Escherichia coli) and -nonproducing (Staphylococcus aureus) bacteria. Despite their gene-coded unresponsiveness to lipopolysaccharide endotoxin and lymphokines and their defective tumoricidal activity, proteose peptone-induced C3H/HeJ macrophages did not display a defective phagocytic capacity, but rather displayed an enhanced phagocytosis of both bacterial strains compared with macrophages from closely related C3H/HeN mice. Unstimulated peritoneal resident C3H/HeJ macrophages, on the other hand, displayed a normal phagocytic activity toward E. coli and enhanced phagocytosis toward S. aureus.

scholarly journals Escherichia coli and Staphylococcus aureus responsible for bovine mastitis sensitivity to the essential oil of Algerian Thymus fontanesii Boiss. et Reut.

2020 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
Bendella Amina nor elhouda ◽  
Ghazi Kheira ◽  
Meliani Samia
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Bovine Mastitis ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Zones Of Inhibition

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.

scholarly journals Antibacterial Activity of Lemongrass (Cymbopogon nardus) Ethanolic Extract

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Waras Nurcholis ◽  
Mira Takene ◽  
Ratna Puspita ◽  
Lisnawati Tumanggor ◽  
Eka Nurul Qomariyah ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Infectious Diseases ◽  
Ethanolic Extract ◽  
Leaf Extracts ◽  
E Coli ◽  
Cymbopogon Nardus ◽  
And Staphylococcus Aureus

Infectious diseases are a disease caused by bacteria such as Escherichia coli and Staphylococcus aureus. One way to overcome the disease by using antibiotics. However, wise use can lead to antibiotic resistance, so many bacteria are resistant to antibiotics. Therefore it is necessary to search the natural compounds as antibacterials, one of them by using lemongrass (Cymbopogon nardus). This study aims to determine the effectiveness of leaf extracts, stems, and roots lemongrass as antibacterial. The method used in this research is the disc method. Bacteria used are E. coli and S. aureus. The results show extracts of roots, stems, and leaf has activity against S. aureus, while  E. coli shows no activity as antibacterial, it can be possible because of the different properties of the bacteria.   Keywords: anti-bacteria, lemongrass, Escherichia coli, Staphylococcus aureus

scholarly journals The spectrum of antibacterial activity of human defensins and cathelicidin against gram-positive and gram-negative bacterial strains isolated from hospitalized patients

2020 ◽  
Author(s):  
Albert Bolatchiev
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Hospitalized Patients ◽  
New Drugs ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Conventional Antibiotics ◽  
Human Defensins

AbstractBackgroundTo date, there is a spread of resistance of microorganisms to antibiotics. To solve this problem, the search and development of new drugs with antibacterial activity is necessary. Antimicrobial peptides (AMPs) have pronounced antibacterial activity and may be promising candidates for the role of new drugs. Besides, AMPs can be used to overcome conventional antibiotics resistance due to the possible synergistic effect. In this work, the combined effect of some AMPs (human defensins, HNP-1, hBD-1, hBD-3 and cathelicidin, LL-37) with conventional antibiotics (vancomycin and imipenem) against gram-positive (Enterococcus faecalis; Staphylococcus aureus, methicillin-sensitive, MSSA, and methicillin-resistant, MRSA) and gram-negative (Escherichia coli; Klebsiella pneumoniae; Pseudomonas aeruginosa) bacterial strains was investigated.MethodsBacterial strains were isolated from hospitalized patients of the intensive care unit. Commercially available AMPs (HNP-1, hBD-1, hBD-3, LL-37 by Cloud-Clone Corp., USA) and antibiotics, vancomycin (Sandoz, Slovenia) and imipenem (Merck Sharp and Dohme, USA) were used. Antibiotic resistance phenotypes of isolated bacterial strains were carried out using the disk diffusion method. The standard checkerboard assays were used to study minimum inhibitory concentrations (MIC) of antimicrobials. The combined microbicidal effect of two substances (AMP+conventional antibiotic) was assessed by the fractional inhibitory concentration index (FICI). If FICI ≤ 0,5, then it was considered that two substances showed synergism of action; if 0.5 < FICI < 4 – no interaction; if FICI > 4 – antagonism.ResultsAll studied AMPs had antibacterial activity against the studied strains. hBD-3 showed the lowest MICs compared to other AMPs. MIC of hBD-3 against S. aureus (MSSA and MRSA), E. coli, K. pneumoniae was the same – 0.5 mg/L, and against P. aeruginosa it was 2 mg/L. The combinations HNP-1+vancomycin (against E. faecalis) and hBD-3+imipenem (against E. coli, K. pneumoniae, P. aeruginosa) according to FICI values have shown the synergistic effect. The results of this study can be used to develop novel antibiotics based on AMPs. Also, in some cases, AMPs can help to overcome resistance to conventional antibiotics.

Molecular Characterization of Antibiotic Resistance Gene Pattern of Staphylococcus aureus and Escherichia coli in Mastitis Affected Dairy Cows

2020 ◽  
Author(s):  
T. Ramasamy ◽  
S. Keerthana ◽  
M.R. Srinivasan ◽  
D. Chandrasekar ◽  
K. Porteen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Molecular Characterization ◽  
Antibiotic Sensitivity ◽  
Growth Media ◽  
E Coli ◽  
Sensitivity Pattern

Background: Antimicrobial resistance is one of the latest challenges facing the scientific community. Raising the drug resistance is caused mainly by indiscriminate usage of antibiotics in human and animal subjects and the spread of antibiotic resistance between the two has an emerging global threat. Hence, current study aimed to study the antimicrobial resistance pattern and molecular detection of antibiotic resistance genes in Staphylococcus aureus and Escherichia coli isolated from mastitis affected cows. Methods: Milk samples from mastitis affected cows were subjected to antibiotic sensitivity test and screened for presence of Staphylococcus aureus and Escherichia coli using differential growth media. Molecular characterization of Staphylococcus aureus and Escherichia coli was done with the help of PCR by amplification of ‘nuc’ and ‘uspA’ gene respectively. MICs of Penicillin and Tetracycline were determined using microdilution method. Result: Antibiotic sensitivity pattern for Penicillin G, Ampicillin, Amoxycillin, Cefotaxime, Ceftriaxone, Azithromycin, Ciprofloxacin, Gentamicin, Oxytetracycline, Tetracycline and Vancomycin were 74.19%, 100%, 93.50%, 61.29%, 29%, 35.48%, 9.70%, 9.70%, 70.96% and 70.96% respectively. More than 87.90% of the S. aureus and 50% of the E. coli isolated were resistant to â-lactam antibiotics while 75% of the E.coli and 65.70% of the S. aureus isolated were resistant to Tetracycline antibiotics. The MICs of Penicillin for S.aureus and E.coli are 26.88 µg/ml and 13.54 µg/ml respectively and the MICs of Tetracycline for S. aureus and E. coli are 243.75 µg/ml and 960.93 µg/ml respectively which is 8-9 folds higher than the standard MICs. From the present study, it can be inferred that bovine mastitis cases are highly resistant to antimicrobial drugs. Results further indicate that Staphylococcus aureus and Escherichia coli are both resistant to Penicillin and Tetracycline with very high MIC.

ANTIBIOTIC SUSCEPTIBILITY OF BACTERIAL STRAINS, WITH SPECIAL REFERENCE TO ESCHERICHIA COLI ISOLATED FROM URINARY TRACT INFECTIONS IN RURAL MAHARASHTRA

2016 ◽  
Vol 10 (1) ◽  
pp. 202
Author(s):  
Sunil Shivaputrayya Gidamudi ◽  
Gaurav V Salunke
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Multiple Antibiotic Resistance ◽  
Bacterial Strains ◽  
Cross Sectional ◽  
E Coli ◽  
Sensitivity Pattern ◽  
Tract Infections

ABSTRACTObjective: The objective of this study was to find out the etiology of urinary tract infections (UTIs) in patients attending B.K.L. Walawalkar Hospital,Dervan and to determine their antibiotic sensitivity pattern to currently used antimicrobial agents.Methods: A cross-sectional study was conducted in a rural hospital of Konkan Maharashtra, and urine samples were collected from368 clinically - suspected cases of UTIs using the mid-stream “clean catch” method and was tested and cultured using standard procedures. Antimicrobialsusceptibility test (AST) was performed for the isolated pathogens according to the Clinical and Laboratory Standards Institute guidelines.Results: Escherichia coli (54.84%) was the most prevalent uropathogen. 76.47% of the isolated E. coli were found to be extended spectrum betalactamase producers. A higher prevalence rate of resistance was seen among E. coli to the commonly prescribed antibiotic agents. 32 (94.11%) of34 E. coli isolates recovered had multiple antibiotic resistance (MAR), with 16 isolates (50%) possessing MAR indices of 0.6.Conclusion: The study indicates the isolated microorganisms in UTI showed very high resistance to the commonly prescribed antimicrobial drugs.This suggests the monitoring and rational use of the antimicrobial agents.Keywords: Mid-stream, Culture, Uropathogen, Resistance, Multiple antibiotic resistance.

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