Combination effects of chemotherapeutic agents I. Antagonistic effects of 1,10-phenanthroline with nalidixic acid and piromidic acid on the growth of Escherichia coli

1977 ◽  
Vol 3 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Shigeru Yamabe ◽  
Masanao Shimizu
Keyword(s):  
Escherichia Coli ◽  
Nalidixic Acid ◽  
Chemotherapeutic Agents ◽  
Antagonistic Effects ◽  
Combination Effects ◽  
Piromidic Acid

scholarly journals Mechanistic insights into synergy between nalidixic acid and tetracycline against clinical isolates of Acinetobacter baumannii and Escherichia coli

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Amit Gaurav ◽  
Varsha Gupta ◽  
Sandeep K. Shrivastava ◽  
Ranjana Pathania
Keyword(s):  
Escherichia Coli ◽  
Acinetobacter Baumannii ◽  
Nalidixic Acid ◽  
Bacterial Infections ◽  
Clinical Isolates ◽  
Hospital Environment ◽  
Infection Model ◽  
Drug Resistant ◽  
E Coli

AbstractThe increasing prevalence of antimicrobial resistance has become a global health problem. Acinetobacter baumannii is an important nosocomial pathogen due to its capacity to persist in the hospital environment. It has a high mortality rate and few treatment options. Antibiotic combinations can help to fight multi-drug resistant (MDR) bacterial infections, but they are rarely used in the clinics and mostly unexplored. The interaction between bacteriostatic and bactericidal antibiotics are mostly reported as antagonism based on the results obtained in the susceptible model laboratory strain Escherichia coli. However, in the present study, we report a synergistic interaction between nalidixic acid and tetracycline against clinical multi-drug resistant A. baumannii and E. coli. Here we provide mechanistic insight into this dichotomy. The synergistic combination was studied by checkerboard assay and time-kill curve analysis. We also elucidate the mechanism behind this synergy using several techniques such as fluorescence spectroscopy, flow cytometry, fluorescence microscopy, morphometric analysis, and real-time polymerase chain reaction. Nalidixic acid and tetracycline combination displayed synergy against most of the MDR clinical isolates of A. baumannii and E. coli but not against susceptible isolates. Finally, we demonstrate that this combination is also effective in vivo in an A. baumannii/Caenorhabditis elegans infection model (p < 0.001)

scholarly journals Lethal Action of Quinolones against a Temperature-Sensitive dnaB Replication Mutant of Escherichia coli

2006 ◽  
Vol 50 (1) ◽  
pp. 362-364 ◽  
Author(s):  
Xilin Zhao ◽  
Muhammad Malik ◽  
Nymph Chan ◽  
Alex Drlica-Wagner ◽  
Jian-Ying Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Dna Replication ◽  
Nalidixic Acid ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Lethal Action ◽  
Inhibition Of Protein Synthesis

ABSTRACT Inhibition of DNA replication in an Escherichia coli dnaB-22 mutant failed to block quinolone-mediated lethality. Inhibition of protein synthesis by chloramphenicol inhibited nalidixic acid lethality and, to a lesser extent, ciprofloxacin lethality in both dnaB-22 and wild-type cells. Thus, major features of quinolone-mediated lethality do not depend on ongoing replication.

scholarly journals The Effect of Antimicrobial Drugs Tylocolinum, Tetragold and Cidisept-o on Escherichia coli Ultrastructure

2013 ◽  
Vol 2 (3) ◽  
pp. 65
Author(s):  
A. G. Shakhov ◽  
D. V. Fedosov ◽  
L. Y. Sashnina ◽  
O. V. Kazimirov
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Water Solution ◽  
Uranyl Acetate ◽  
Chemotherapeutic Agents ◽  
Control Culture ◽  
New Drugs ◽  
Ultrastructural Changes ◽  
The Impact

<p>As a result of wide antibiotics, sulfonamides and other antimicrobial agents usage for the therapy of the animals with the bacterial infections caused by various causative agents including <em>Escherichia coli</em>, many microorganisms gained resistance to the chemotherapeutic agents. New combined drugs are being worked out during recent years, the components of which have various influence mechanisms on the bacterial cell that helps to provide resistance forming control. The results of the researches of the new antimicrobial agents, containing antibiotics in their composition, and non-antibiotic agent influence on the ultrastructure of <em>Escherichia coli</em> are represented in this study.</p> <p>5-hour <em>Escherichia coli 866</em> culture was processed by the drugs of the minimum bactericidal (Tylocolinum-0.39 µg/ml, Tetragold-6.25 µg/ml, Cidisept-o-25 µg/ml) and 4-time concentrations during 3 hours. Samples and control culture (without drugs) were fixed by the 2.5% glutaricdialdehyde on the s-Collidine Buffer, dehydrated in the ethanol with rising concentration, filled in epoxies. Ultrathin slices were stained by 2% water solution of uranyl acetate and lead citrate for 10 minutes. Then they were examined with the use of the electron microscope JEM-100 CX II by JEOL.</p> <p>The research showed deep ultrastructural changes in <em>Escherichia coli</em> cells under the antimicrobial agent influence determined by synergistic effect of combined Tylocolinum and Tetragold drugs components, possessing various bacteria influencing mechanisms, and aldehyde that is a component of Cidisept-o.</p> The electron microscopy usage allows to get unique information about the impact consequences of the traditional improved drugs and new drugs with antimicrobial activity on the bacterial infectious agents.

scholarly journals Investigation of the antimicrobial activity of danofoloxacin against bacteria pathogens in goats

2020 ◽  
Vol 22 (97) ◽  
pp. 74-78
Author(s):  
T. I. Stetsko ◽  
Ya. M. Liubenko ◽  
V. N. Padovskyi ◽  
L. L. Ostrovska ◽  
O. Yo. Kalinina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacterial Infections ◽  
Chemotherapeutic Agents ◽  
Diffusion Method ◽  
Bacteriostatic Activity ◽  
Intestinal Infection ◽  
Sensitivity Testing ◽  
First Choice

Fluoroquinolones are critical antimicrobials for both human and veterinary medicine. Due to their unique mechanism of antimicrobial action and good pharmacokinetic properties, they are often the first choice drugs in the treatment of bacterial infections in animals. The purpose of the investigation was to study the antimicrobial activity of a third-generation fluoroquinolone antibiotic of danofloxacin against bacteria, pathogens of respiratory and intestinal infection in goats. The samples of the nasal outflows (respiratory infection) and fecal masses (intestinal infection) were collected from clinically ill goats for microbiological studies. The sensitivity test of the microflora of the biomaterial, carried out by the disco-diffusion method, showed that the microorganisms of all the samples were sensitive to danofloxacin. Bacteria Streptococcus pneumonia (n = 10), Staphylococcus aureus (n = 4) and Escherichia coli (n = 2) were isolated and identified from nasal exudate samples (n = 10). Pathogenic strains of Escherichia coli were isolated from all faecal samples (n = 12). The degree of bacteriostatic activity of danofloxacin was determined by establishing its minimum inhibitory concentration (MIC) for bacterial isolates by sequential dilutions in a liquid nutrient medium. The average MIC of danofloxacin for Streptococcus pneumoniae isolates was 0.26 ± 0.13 μg/ml and for Staphylococcus aureus isolates – 0.25 ± 0.075 μg/ml. For Escherichia coli strains isolated from faeces of goats suffering from coli infection, the average MIC of danofloxacin was 0.38 ± 0.12 μg/ml (range 0.2 to 0.8 μg/ml). Antimicrobial sensitivity testing have shown a high level of bacteriostatic activity of danofloxacin against bacteria, pathogens of respiratory and intestinal infections in goats. This may be the argument for the use of danofloxacin-based chemotherapeutic agents in the treatment of bacterial infections in goats, especially for the empirical approach to therapy.

scholarly journals Combination Effects of Cymbopogon sp. Essential Oil on Selected Bacteria

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Nur Aishah Abdul Wahab ◽  
Hairul Shahril Muhamad ◽  
Nabilah Ahmad Alhadi ◽  
Salina Mat Radzi ◽  
Maryam Mohamed Rehan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Essential Oils ◽  
Staphylococcus Epidermidis ◽  
Antimicrobial Agents ◽  
Synergistic Effects ◽  
Combination Effects ◽  
Cymbopogon Flexuosus ◽  
Combination Study

Combination effects between Cymbopogon flexuosus and Cymbopogon nardus essential oils were studied to determine whether the combination could emerge as better and more powerful antimicrobial agents against six selected bacteria includes Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis. This combination study exhibited 40.67% additive, 28.67% antagonistic, 16.00% indifferent and 14.66% synergistic effects. C. flexuosus and C. nardus essential oils in combination showed a high inhibitory activity against S. aureus with 16% synergistic, 64% additive and 20% indifferent effects.

scholarly journals In Vitro Antimicrobial Sensitivity of Escherichia coli Isolated from Clinical Sources

1970 ◽  
Vol 34 (1) ◽  
pp. 99-101
Author(s):  
Mohammad Shahriar ◽  
Mahboob Hossain ◽  
Shaila Kabir
Keyword(s):  
Escherichia Coli ◽  
Nalidixic Acid ◽  
E Coli ◽  
Antimicrobial Sensitivity ◽  
Sensitivity Pattern ◽  
Low Sensitivity ◽  
Academy Of Sciences ◽  
Higher Sensitivity

A study of antimicrobial sensitivity of Escherichia coli (E. coli) isolated from clinical sourcesof different diagnostic centers of Dhaka, Bangladesh was carried out to facilitate the choice of drugin the management of E. coli induced symptoms. Very low sensitivity of E. coli towards ampicillin(4%), aztreonam (4%), cloxacillin (5%), nalidixic acid (5%), ciprofloxacin (7.5%), ceftriaxone(12.5%), doxycycline (12.5%), ceftazidime (16.25%), co-trimoxazole (20%), chloramphenicol(22.51%), tetracycline (25%), and netilmicin (35%) was observed. Higher sensitivity pattern wasobserved for gentamicin (56%) and only imipenem (95%) showed sensitivity pattern possiblysusceptible enough to consider for the management of E. coli induced cases in the area under study.The low sensitivity to different antimicrobial could be attributed to their prevailing usage and abusein the area under study.Key words: E. coli; Antimicrobial sensitivity; Clinical isolatesDOI: 10.3329/jbas.v34i1.5497Journal of Bangladesh Academy of Sciences, Vol.34, No.1, 99-101, 2010

scholarly journals Characterization of Plasmid-Mediated Quinolone Resistance and Serogroup Distributions of Uropathogenic Escherichia coli among Iranian Kidney Transplant Patients

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Amin Sadeghi ◽  
Mehrdad Halaji ◽  
Amirhossein Fayyazi ◽  
Seyed Asghar Havaei
Keyword(s):  
Escherichia Coli ◽  
Nalidixic Acid ◽  
Kidney Transplant ◽  
Uropathogenic Escherichia Coli ◽  
Quinolone Resistance ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Transplant Patients ◽  
Kidney Transplant Patients ◽  
Plasmid Genes

Introduction. Urinary tract infection (UTI) is one of the most frequent infections in kidney transplant patients (KTPs). This infection is mainly caused by uropathogenic Escherichia coli (UPEC). Plasmid-mediated quinolone resistance (PMQR) was also increasingly identified in UPEC. This study proposed to investigate the frequency of quinolone-resistance plasmid genes and the O-antigen serogroup among UPEC isolated from KTPs and non-KTP with UTI. Methods. Totally, 114 UPEC isolates from 49 KTPs and 65 non-KTPs patients diagnosed with an UPEC-associated UTI were obtained from June 2019 to December 2019 at three laboratory centers in Isfahan, Iran. The isolates were confirmed through phenotypic and genotypic methods. Moreover, the antimicrobial susceptibility test to nalidixic acid, ciprofloxacin, norfloxacin, and ofloxacin was performed using a disk diffusion method. The presence of the qnr gene as well as the serogroup distribution was identified using the PCR method. Result. According to data, the distribution of O1, O2, O4, O16, and O25 serogroups were 3.5%, 2.6, 3.5, 3.5, and 20.2%, respectively. Antibiotic susceptibility pattern revealed that the highest and lowest resistance rates were to nalidixic acid (69.3%) and norfloxacin (43.9%), respectively. Also, the frequency of qnrS and qnrB genes were 33.3% and 15.8%, respectively, while none of the isolates was found to be positive for the qnrA gene. There was no significant association between the presence of qnr genes and higher antibiotic resistance. Conclusion. This study recognized that the qnrS gene, O25 serotype, and resistance to nalidixic acid had the highest frequencies in UPEC strains isolated from UTI patients.

Mechanism of Action of Nalidixic Acid on Escherichia coli VI. Cell-free Studies

1969 ◽  
Vol 97 (1) ◽  
pp. 230-236 ◽  
Author(s):  
James V. Boyle ◽  
Thomas M. Cook ◽  
William A. Goss
Keyword(s):  
Escherichia Coli ◽  
Nalidixic Acid ◽  
Mechanism Of Action
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