A COMPARATIVE STUDY OF THE ACTIVITY OF FIFTY ANTIBIOTIC ACTINOMYCETES AGAINST A VARIETY OF SOIL BACTERIA

1948 ◽  
Vol 26c (6) ◽  
pp. 501-506 ◽  
Author(s):  
G. B. Landerkin ◽  
A. G. Lochhead
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Soil Bacteria ◽  
Bacterial Species ◽  
Antibiotic Activity ◽  
Test Organisms

Fifty actinomycetes, isolated from a variety of soils on the basis of their antibiotic activity against Escherichia coli, were tested against different soil bacteria. Wide variations were noted in susceptibility of the test organisms to the antagonists. Actinomycetes with the most intense antibiotic activity were able to act upon the greatest number of bacterial species.

THE ANTIBIOTIC ACTIVITY OF SOIL MICROORGANISMS AS RELATED TO BACTERIAL PLANT PATHOGENS

1954 ◽  
Vol 32 (5) ◽  
pp. 705-735 ◽  
Author(s):  
Z. A. Patrick
Keyword(s):  
Plant Pathogens ◽  
Bacterial Species ◽  
High Specificity ◽  
Soft Rot ◽  
Soil Microflora ◽  
Antibiotic Activity ◽  
Pathogenic Species ◽  
Xanthomonas Species ◽  
Test Organisms ◽  
Antibiotic Reactions

In an attempted evaluation of the importance of soil antagonisms as a possible factor in the different survival capabilities of some bacterial plant pathogens in the soil environment, a comparison was made of the numbers of antagonists detected when different plant pathogenic species were used as test organisms in determining the "antibiotic potential" of nine "virgin" soils. It was found that there are present among the soil flora a great abundance of microorganisms intrinsically capable of antagonizing most of the bacterial pathogens tested and only for a few species are such antagonists relatively rare. There were great differences in the number of isolates antagonistic to the different pathogenic species, even in the same genus, and there seemed to be a correlation between the numbers of antagonists, as found here, and the capability of a species to maintain itself for long periods in the soil. For the most part the Xanthomonas species appeared to be most sensitive to the antagonistic soil microflora while the soft-rot-causing Erwinia species were most resistant.A comparative study of the antibiotic activity of 120 of the most active antagonistic isolates tested against 28 bacterial plant pathogens showed that each antagonist was characterized by a specific antibacterial spectrum and those antagonists having the most intense antibiotic activity usually inhibited the greatest number of bacterial species. Many antagonists were highly specific, affecting only certain groups or even certain species. The high specificity which characterized some of the antibiotic reactions was used to separate sharply, consistently, and with minimum effort such closely related species as E. carotovora and E. atroseptica or X. corylina and X. juglandis.

scholarly journals N-Acetylcysteine Selectively Antagonizes the Activity of Imipenem in Pseudomonas aeruginosa by an OprD-Mediated Mechanism

2015 ◽  
Vol 59 (6) ◽  
pp. 3246-3251 ◽  
Author(s):  
Jerónimo Rodríguez-Beltrán ◽  
Gabriel Cabot ◽  
Estela Ynés Valencia ◽  
Coloma Costas ◽  
German Bou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Antibiotic Activity ◽  
Simultaneous Treatment ◽  
Content Type ◽  
Sds Page

ABSTRACTThe modulating effect ofN-acetylcysteine (NAC) on the activity of different antibiotics has been studied inPseudomonas aeruginosa. Our results demonstrate that, in contrast to previous reports, only the activity of imipenem is clearly affected by NAC. MIC and checkerboard determinations indicate that the NAC-based modulation of imipenem activity is dependent mainly on OprD. SDS-PAGE of outer membrane proteins (OMPs) after NAC treatments demonstrates that NAC does not modify the expression of OprD, suggesting that NAC competitively inhibits the uptake of imipenem through OprD. Similar effects on imipenem activity were obtained withP. aeruginosaclinical isolates. Our results indicate that imipenem-susceptibleP. aeruginosastrains become resistant upon simultaneous treatment with NAC and imipenem. Moreover, the generality of the observed effects of NAC on antibiotic activity was assessed with two additional bacterial species,Escherichia coliandAcinetobacter baumannii. Caution should be taken during treatments, as the activity of imipenem may be modified by physiologically attainable concentrations of NAC, particularly during intravenous and nebulized regimes.

Structural and functional properties of Escherichia coli-derived nucleoplasmin A comparative study of recombinant and natural proteins

2001 ◽  
Vol 268 (6) ◽  
pp. 1739-1748
Author(s):  
Aitor Hierro ◽  
Jesus M. Arizmendi ◽  
Javier De Las Rivas ◽  
M. Angeles Urbaneja ◽  
Adelina Prado ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Functional Properties ◽  
Structural And Functional Properties

scholarly journals An Understanding of the Global Status of Major Bacterial Pathogens of Milk Concerning Bovine Mastitis: A Systematic Review and Meta-Analysis (Scientometrics)

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 545
Author(s):  
Paramanandham Krishnamoorthy ◽  
Kuralayanapalya P. Suresh ◽  
Kavitha S. Jayamma ◽  
Bibek R. Shome ◽  
Sharanagouda S. Patil ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Management Practices ◽  
Meta Analysis ◽  
Bacterial Species ◽  
Clinical Mastitis ◽  
Therapeutic Interventions ◽  
Coagulase Negative Staphylococcus ◽  
Prevalence Studies ◽  
The World ◽  
Pathogen Prevalence

In this study, the major mastitis pathogen prevalence in the cattle and buffalo of the world was estimated by a meta-analysis. Staphylococcus (S) species, Streptococcus (St) species, and Escherichia coli (Ec) prevalence studies reported during 1979–2019 were collected using online databases, and offline resources. A meta-analysis of these data was done with the meta package in R-Software. The Staphylococcus aureus was the major mastitis pathogen, mostly causing subclinical mastitis, Ec causing clinical mastitis and St causing subclinical and clinical mastitis. The pooled prevalence estimates of S, St, and Ec were 28%, 12%, and 11% in the world from 156, 129, and 92 studies, respectively. The S, St, and Ec prevalences were high in Latin America (51%), Oceania (25%), and Oceania (28%), respectively. Higher S, St, and Ec prevalences were observed by molecular methods, signifying high sensitivity and usefulness for future studies. Among bacterial species, S. aureus (25%) followed by coagulase-negative Staphylococcus species (20%), Escherichia coli (11%), St. agalactiae (9%), St. uberis (9%) were the important pathogens present in the milk of the world. We hypothesize that there is a urgent need to reduce mastitis pathogen prevalence by ensuring scientific farm management practices, proper feeding, therapeutic interventions to augment profits in dairying, and improving animal and human health.

scholarly journals Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

2021 ◽  
Vol 11 (2) ◽  
pp. 541
Author(s):  
Katarzyna Grudlewska-Buda ◽  
Krzysztof Skowron ◽  
Ewa Wałecka-Zacharska ◽  
Natalia Wiktorczyk-Kapischke ◽  
Jarosław Bystroń ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Economic Problem ◽  
Cow Milk ◽  
P Value ◽  
Dairy Herds ◽  
E Coli ◽  
Bonferroni Test

Mastitis is a major economic problem in dairy herds, as it might decrease fertility, and negatively affect milk quality and milk yield. Out of over 150 bacterial species responsible for the udder inflammation, Escherichia coli is one of the most notable. This study aimed to assess antimicrobial susceptibility, resistance to dipping agents and biofilm formation of 150 E. coli strains isolated from milk of cows with subclinical and clinical mastitis. The strains came from three dairy herds located in Northern and Central Poland. The statistical analyses were performed with post-hoc Bonferroni test and chi-square test (including Yates correction). The data with a p value of <0.05 were considered significant. We found that the tested strains were mostly sensitive to antimicrobials and dipping agents. It was shown that 37.33% and 4.67% of strains were resistant and moderately resistant to at least one antimicrobial agent, respectively. No extended-spectrum beta-lactamases (ESBL)-producing E. coli were detected. The majority of strains did not possess the ability to form biofilm or formed a weak biofilm. The strong biofilm formers were found only among strains derived from cows with subclinical mastitis. The lowest bacteria number was noted for subclinical mastitis cows’ strains, after stabilization with iodine (3.77 log CFU × cm−2) and chlorhexidine (3.96 log CFU × cm−2) treatment. In the present study, no statistically significant differences in susceptibility to antibiotics and the ability to form biofilm were found among the strains isolated from cows with subclinical and clinical mastitis. Despite this, infections in dairy herds should be monitored. Limiting the spread of bacteria and characterizing the most common etiological factors would allow proper treatment.

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