Analyzing metabolic variations in different bacterial strains, historical perspectives and current trends – example E. coli

2010 ◽  
Vol 21 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Joseph Shiloach ◽  
Shamlan Reshamwala ◽  
Santosh B Noronha ◽  
Alejandro Negrete
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.


2020 ◽  
Vol 32 (3) ◽  
pp. 580-586
Author(s):  
Ranjit V. Gadhave ◽  
Bhanudas S. Kuchekar

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rong Zhang ◽  
Ning Dong ◽  
Zhangqi Shen ◽  
Yu Zeng ◽  
Jiauyue Lu ◽  
...  

Abstract Emergence of tigecycline-resistance tet(X) gene orthologues rendered tigecycline ineffective as last-resort antibiotic. To understand the potential origin and transmission mechanisms of these genes, we survey the prevalence of tet(X) and its orthologues in 2997 clinical E. coli and K. pneumoniae isolates collected nationwide in China with results showing very low prevalence on these two types of strains, 0.32% and 0%, respectively. Further surveillance of tet(X) orthologues in 3692 different clinical Gram-negative bacterial strains collected during 1994–2019 in hospitals in Zhejiang province, China reveals 106 (2.7%) tet(X)-bearing strains with Flavobacteriaceae being the dominant (97/376, 25.8%) bacteria. In addition, tet(X)s are found to be predominantly located on the chromosomes of Flavobacteriaceae and share similar GC-content as Flavobacteriaceae. It also further evolves into different orthologues and transmits among different species. Data from this work suggest that Flavobacteriaceae could be the potential ancestral source of the tigecycline resistance gene tet(X).


2021 ◽  
Vol 22 (7) ◽  
pp. 3539
Author(s):  
Anastasia Meretoudi ◽  
Christina N. Banti ◽  
Panagiotis K. Raptis ◽  
Christina Papachristodoulou ◽  
Nikolaos Kourkoumelis ◽  
...  

The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles (AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA). The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis, and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9, 12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were 10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low (66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently, pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious contact lenses.


Author(s):  
Trâm Quế Anh

TÓM TẮT Đặt vấn đề: Xác định đúng căn nguyên gây NKĐTN và mức độ kháng kháng sinh của các vi khuẩn sẽ giúp cho việc điều trị có hiệu quả, giảm được chi phí điều trị, hạn chế sự gia tăng vi khuẩn đề kháng kháng sinh. Đối tượng và phương pháp nghiên cứu: Các chủng VK gây nhiễm khuẩn đương tiết niệu phân lập được tại bệnh viện Hữu nghị Đa khoa Nghệ An từ 1/2020 đến 12/2020. Thiết kế nghiên cứu: Cắt ngang mô tả. Kết quả: Phân lập được 473 chủng vi khuẩn gây NKĐTN, trong đó, E. coli 38,48%; P. aeruginosa 14,15; Enterococcus sp 10,57; K. pneumoniae 13,32%. E. coli: kháng các kháng sinh Cephalosporine, Quinolones từ 56,7 - 63,8%, Carbapenem 4,5 - 6,2%, sinh ESBL 49,4%. P. aeruginosa: đã kháng các kháng sinh thử nghiệm từ 59,1 - 69,2%. Enterococcus sp: kháng với các kháng sinh nhóm Quinolone 73,5%, kháng Vancomycin 8,3%; Chưa ghi nhận đề kháng Linezolid. K. pneumoniae: kháng nhóm Cephalosporin, Quinolone từ 66,7 - 74,6%, đề kháng với Carbapenem từ 46,0 - 50,8%. Kết luận: Các vi khuẩn gây nhiễm khuẩn tiết niệu thường gặp là: E. coli, P. aeruginosa, Enterococcus sp. K. pneumoniae. Các vi khuẩn phân lập được đã đề kháng với nhiều kháng sinh thường dùng với các mức độ khác nhau. Xuất hiện các chủng vi khuẩn Gram âm kháng Carbapenem, Gram dương kháng Vancomycin. Từ khóa: Nhiễm khuẩn tiết niệu, E.coli, Klebsiella, P.aeruginosa, Enterococcus sp ABSTRACT RESEARCH OF ANTIBIOTICS RESISTANCE OF BACTERIA STRAINS CAUSING URINARY TRACT INFECTIONS ISOLATED AT NGHEAN FRIENDSHIP GENERAL HOSPITAL Background: The good identification of UTI microorganism and their antimicrobial susceptibility would promote the effective treatment, reduce the cost as well as the emergence of drug resistant bacteria. Methods: Bacterial strains causing urinary tract infections were isolated at Nghe An Friendship General Hospital from 1/2020 to 12/2020. Study design: Descriptive cross section. Results: 473 bacterial strains causing UTIs were isolated, in which, E. coli 38.48%; P. aeruginosa 14.15; Enterococcus sp 10.57; K. pneumoniae 13.32%. E. coli: resistant to Cephalosporin antibiotics, Quinolones from 56.7 - 63.8%, Carbapenem 4.5 - 6.2%, producing ESBL 49.4%. P. aeruginosa: was resistant to the tested antibiotics from 59.1 - 69.2%. Enterococcus sp: resistant to Quinolone antibiotics 73.5%, resistant to Vancomycin 8.3%; Linezolid resistance has not been recorded. K. pneumoniae: resistant to Cephalosporin, Quinolone from 66.7 - 74.6%, resistant to Carbapenem from 46.0 - 50.8%. Conclusion: Common bacteria causing urinary tract infections are: E. coli, P. aeruginosa, Enterococcus sp. K. pneumoniae. The isolates were resistant to many commonly used antibiotics to varying degrees. Occurrence of strains of Gram - negative bacteria resistant to Carbapenem, Gram - positive resistant to Vancomycin. Keywords: Urinary Tract infections, E. coli, Klebsiella, P. aeruginosa, Enterococcus sp.


2014 ◽  
Vol 2 (4) ◽  
pp. 521-524
Author(s):  
RP Praveen ◽  
Ashalantha Nair

The aim of the present study was to compare the antimicrobial efficacy of methanolic extract of root, callus and fruit of Myxopyrum smilacifolium Blume. Antimicrobial activity was tested using agar well diffusion with four bacterial strains viz: Escherechia coli, Enterococcus faecalis, Bacillus subtilis and Staphylococcus aureus of which E. coli alone was gram negative. The fungal strain employed was Candida albicans. Root extracts shown to be effective only against B. subtilis. Fruit extracts showed the maximum antimicrobial activity against all the microbial species considered for the current study except against S. aureus. Highlight of the present study was the antimicrobial activity of callus extracts. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11362  Int J Appl Sci Biotechnol, Vol. 2(4): 521-524 


Antibiotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 98 ◽  
Author(s):  
Eunice Mgbeahuruike ◽  
Pia Fyhrquist ◽  
Heikki Vuorela ◽  
Riitta Julkunen-Tiitto ◽  
Yvonne Holm

Piper guineense is a food and medicinal plant commonly used to treat infectious diseases in West-African traditional medicine. In a bid to identify new antibacterial compounds due to bacterial resistance to antibiotics, twelve extracts of P. guineense fruits and leaves, obtained by sequential extraction, as well as the piperine and piperlongumine commercial compounds were evaluated for antibacterial activity against human pathogenic bacteria. HPLC-DAD and UHPLC/Q-TOF MS analysis were conducted to characterize and identify the compounds present in the extracts with promising antibacterial activity. The extracts, with the exception of the hot water decoctions and macerations, contained piperamide alkaloids as their main constituents. Piperine, dihydropiperine, piperylin, dihydropiperylin or piperlonguminine, dihydropiperlonguminine, wisanine, dihydrowisanine and derivatives of piperine and piperidine were identified in a hexane extract of the leaf. In addition, some new piperamide alkaloids were identified, such as a piperine and a piperidine alkaloid derivative and two unknown piperamide alkaloids. To the best of our knowledge, there are no piperamides reported in the literature with similar UVλ absorption maxima and masses. A piperamide alkaloid-rich hexane leaf extract recorded the lowest MIC of 19 µg/mL against Sarcina sp. and gave promising growth inhibitory effects against S. aureus and E. aerogenes as well, inhibiting the growth of both bacteria with a MIC of 78 µg/mL. Moreover, this is the first report of the antibacterial activity of P. guineense extracts against Sarcina sp. and E. aerogenes. Marked growth inhibition was also obtained for chloroform extracts of the leaves and fruits against P. aeruginosa with a MIC value of 78 µg/mL. Piperine and piperlongumine were active against E. aerogenes, S. aureus, E. coli, S. enterica, P. mirabilis and B. cereus with MIC values ranging from 39–1250 µg/mL. Notably, the water extracts, which were almost devoid of piperamide alkaloids, were not active against the bacterial strains. Our results demonstrate that P. guineense contains antibacterial alkaloids that could be relevant for the discovery of new natural antibiotics.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Phan-Canh Trinh ◽  
Le-Thi-Thanh Thao ◽  
Hoang-Tran-Viet Ha ◽  
TuAnh Nguyen

Asteraceae species were widely applied in traditional medicines in Asian countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, and Artemisia vulgaris indicated significant inhibitory effects on Staphylococcus aureus and Candida spp. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, A. conyzoides, and Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In a study on clinical isolates, ethyl acetate fraction from A. conyzoides flower displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25–10 mg/ml and 5–12.5 mg/ml, respectively. DPPH-scavenging assay indicated that T. erecta extract had the lowest IC50 (17.280 μg/ml) and is 2.4 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and therefore could be applied for prophylactic treatment of urinary infection.


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