scholarly journals DefiningEscherichia colias a health-promoting microbe against intestinalPseudomonas aeruginosa

2019 ◽  
Author(s):  
Theodoulakis Christofi ◽  
Stavria Panayidou ◽  
Irini Dieronitou ◽  
Christina Michael ◽  
Yiorgos Apidianakis
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Lactic Acid ◽  
Wound Infections ◽  
Human Gut ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Intestinal Pathogens ◽  
Health Promoting

AbstractGut microbiota acts as a barrier against intestinal pathogens, but species-specific protection of the host from infection remains relatively unexplored. Taking a Koch’s postulates approach in reverse to define health-promoting microbes we find thatEscherichia colinaturally colonizes the gut of healthy mice, but it is depleted from the gut of antibiotic-treated mice, which become susceptible to intestinal colonization byPseudomonas aeruginosaand concomitant mortality. Reintroduction of fecal bacteria andE. coliestablishes a high titer ofE. coliin the host intestine and increases defence againstP. aeruginosacolonization and mortality. Moreover, diet is relevant in this process because high sugars or dietary fat favoursE. colifermentation to lactic acid andP. aeruginosagrowth inhibition. To the contrary, low sugars allowP. aeruginosato produce the oxidative agent pyocyanin that inhibitsE. coligrowth. Our results provide an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.Author SummaryHere we interrogate the conundrum as to whyPseudomonas aeruginosais not a clinical problem in the intestine as opposed to other tissues.P. aeruginosainteracts with Neisseria, Streptococcus, Staphylococcus and Actinomyces species found in the human lung. These are predominantly gram-positive bacteria that induceP. aeruginosavirulence. Moreover, peptidoglycan, which is abundant in gram-positive bacteria, can directly trigger the virulence ofP. aeriginosa. We reasoned thatP. aeruginosamight be benign in the human gut due to the inhibitory action of benign gram-negative intestinal bacteria, such asEscherichia coli. Therefore, we dissected the antagonism betweenE. coliandP. aeruginosaand the effect of a conventional, a fat-, a carbohydrate-and a protein-based diet in intestinal dysbiosis. Our findings support the notion that an unbalanced diet or antibiotics induces gut dysbiosis by the elimination of commensalE. coli, in addition to lactic acid bacteria, imposing a gut environment conducive toP. aeruginosainfection. Moreover, commensalE. coliprovides an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.

scholarly journals Metabolic output defines Escherichia coli as a health-promoting microbe against intestinal Pseudomonas aeruginosa

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Theodoulakis Christofi ◽  
Stavria Panayidou ◽  
Irini Dieronitou ◽  
Christina Michael ◽  
Yiorgos Apidianakis
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Short Chain Fatty Acids ◽  
High Titre ◽  
Important Indicator ◽  
High Sugar Concentration ◽  
Intestinal Pathogens ◽  
Health Promoting ◽  
Species Specific ◽  
Metabolic Output

Abstract Gut microbiota acts as a barrier against intestinal pathogens, but species-specific protection of the host from infection remains relatively unexplored. Although lactobacilli and bifidobacteria produce beneficial lactic and short-chain fatty acids in the mammalian gut, the significance of intestinal Escherichia coli producing these acids is debatable. Taking a Koch’s postulates approach in reverse, we define Escherichia coli as health-promoting for naturally colonizing the gut of healthy mice and protecting them against intestinal colonization and concomitant mortality by Pseudomonas aeruginosa. Reintroduction of faecal bacteria and E. coli in antibiotic-treated mice establishes a high titre of E. coli in the host intestine and increases defence against P. aeruginosa colonization and mortality. Strikingly, high sugar concentration favours E. coli fermentation to lactic and acetic acid and inhibits P. aeruginosa growth and virulence in aerobic cultures and in a model of aerobic metabolism in flies, while dietary vegetable fats - not carbohydrates or proteins - favour E. coli fermentation and protect the host in the anaerobic mouse gut. Thus E. coli metabolic output is an important indicator of resistance to infection. Our work may also suggest that the lack of antimicrobial bacterial metabolites in mammalian lungs and wounds allows P. aeruginosa to be a formidable microbe at these sites.

scholarly journals What an Escherichia coli Mutant Can Teach Us About the Antibacterial Effect of Chlorophyllin

2019 ◽  
Vol 7 (2) ◽  
pp. 59 ◽  
Author(s):  
Marcus Krüger ◽  
Peter Richter ◽  
Sebastian Strauch ◽  
Adeel Nasir ◽  
Andreas Burkovski ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
High Sensitivity ◽  
Coli Strain ◽  
Photodynamic Treatment ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bacterial Model

Due to the increasing development of antibiotic resistances in recent years, scientists search intensely for new methods to control bacteria. Photodynamic treatment with porphyrins such as chlorophyll derivatives is one of the most promising methods to handle bacterial infestation, but their use is dependent on illumination and they seem to be more effective against Gram-positive bacteria than against Gram-negatives. In this study, we tested chlorophyllin against three bacterial model strains, the Gram-positive Bacillus subtilis 168, the Gram-negative Escherichia coli DH5α and E. coli strain NR698 which has a deficient outer membrane, simulating a Gram-negative “without” its outer membrane. Illuminated with a standardized light intensity of 12 mW/cm2, B. subtilis showed high sensitivity already at low chlorophyllin concentrations (≤105 cfu/mL: ≤0.1 mg/L, 106–108 cfu/mL: 0.5 mg/L), whereas E. coli DH5α was less sensitive (≤105 cfu/mL: 2.5 mg/L, 106 cfu/mL: 5 mg/L, 107–108 cfu/mL: ineffective at ≤25 mg/L chlorophyllin). E. coli NR698 was almost as sensitive as B. subtilis against chlorophyllin, pointing out that the outer membrane plays a significant role in protection against photodynamic chlorophyllin impacts. Interestingly, E. coli NR698 and B. subtilis can also be inactivated by chlorophyllin in darkness, indicating a second, light-independent mode of action. Thus, chlorophyllin seems to be more than a photosensitizer, and a promising substance for the control of bacteria, which deserves further investigation.

Transfer RNA genes and their significance to codon usage in the Pseudomonas aeruginosa lamboid bacteriophage D3

1999 ◽  
Vol 45 (9) ◽  
pp. 791-796 ◽  
Author(s):  
Andrew M Kropinski ◽  
Mary Jo Sibbald
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Codon Usage ◽  
Transfer Rna ◽  
Trna Genes ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Early Region ◽  
Phage Proteins ◽  
Rna Genes

Using tRNAscan-SE and FAStRNA we have identified four tRNA genes in the delayed early region of the bacteriophage D3 genome (GenBank accession No. AF077308). These are specific for methionine (AUG), glycine (GGA), asparagine (AAC), and threonine (ACA). The D3 Thr- and Gly-tRNAs recognize codons, which are rarely used in Pseudomonas aeruginosa and presumably, influence the rate of translation of phage proteins. BLASTN searches revealed that the D3 tRNA genes have homology to tRNA genes from Gram-positive bacteria. Analysis of codon usage in the 91 ORFs discovered in D3 indicates patterns of codon usage reminiscent of Escherichia coli or P. aeruginosa.Key words: bacteriophage, Pseudomonas, D3, tRNA, codon usage.

scholarly journals Postantibiotic Effect of Trovafloxacin against Gram-Positive and -Negative Organisms

1998 ◽  
Vol 42 (6) ◽  
pp. 1503-1505 ◽  
Author(s):  
G. A. Pankuch ◽  
M. R. Jacobs ◽  
P. C. Appelbaum
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Bactericidal Activity ◽  
The Other ◽  
Postantibiotic Effect ◽  
Gram Positive ◽  
E Coli

ABSTRACT Trovafloxacin pneumococcal and staphylococcal postantibiotic effects (PAEs) were 0.7 to 1.8 and 0.7 to 2.4 h, respectively. ForEscherichia coli and Pseudomonas aeruginosa, PAEs were 2.4 to 4.4 h. Pneumococcal and staphylococcal postantibiotic sub-MIC effects (PA-SMEs) (0.4 times the MIC) were 2.3 to 3.7 and 2.4 to >9.2 h, respectively, and E. coliPA-SMEs (0.3 times the MIC) were 6.8 to >12.0 h. For one P. aeruginosa strain, the PA-SME (0.4 times the MIC) was >10 h; in the other, rapid bactericidal activity precluded measurement.

scholarly journals Categorization of Bacterial Pathogens Present in Infected Wounds and their Antibiotic Resistance Profile Recovered from Patients Attending Rizgary Hospital-Erbil

2021 ◽  
Vol 9 (2) ◽  
pp. 64-70
Author(s):  
Ahmed A. Al-Naqshbandi ◽  
Hedy A. Hassan ◽  
Mahmoud A. Chawsheen ◽  
Haval H. Abdul Qader
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Resistant Bacteria ◽  
Antibiotic Prescribing ◽  
Gram Negative Bacteria ◽  
Wound Infections ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Wound infection with antibiotic-resistant bacteria can extend a patients’ debility and increase the expense of treatment in the long term; therefore, careful management of patients with wound infections is necessary to avoid complications. The usage of antimicrobial agent is a major factor in resistance development. This study aims to understand the causes of wound infections, as well as the criteria for diagnosing them for more sensible antibiotic prescribing. Samples from 269 wound patients were collected, and cultured for bacterial growth. Gram stain technique, bacterial identification via VITEK 2 compact system were investigated in this study. Gram negative bacteria accounted for 59.15% of the total isolates, while pathogenic gram positive bacteria accounted for 40.85% of total isolates. Escherichia coli and Pseudomonas aeruginosa are the dominant pathogenic gram negative bacteria in wounds, while Staphylococcus aureus, and Staphylococcus epidermidis are the dominant pathogenic gram positive bacteria. Pseudomonas aeruginosa showed 100% resistance to the majority of antibiotic tested, including Ampicillin, Amoxicillin/Clavulanic Acid, Aztreona, Ceftriaxone, and others. Staphylococcus aureus and Staphylococcus epidermidis are 100% resistant to Ampicillin, Ceftriaxone, and Cefotaxime. For more efficient antibiotic prescriptions, the causative microorganisms, and their current susceptibility patterns need to be mandated for testing before prescribing any antibiotics to patients. Prescriptions are frequently based solely on general information about the antibiotic's function, rather than on individual response variation to the pathogen and the antibiotic. Particularly when the common pathogens in this study show multidrug resistance in wounds.

scholarly journals Evaluation of Antibacterial Activity of Three Quaternary Ammonium Disinfectants on Different Germs Isolated from the Hospital Environment

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Amal Ramzi ◽  
Bouchra Oumokhtar ◽  
Yassine Ez zoubi ◽  
Touria Filali Mouatassem ◽  
Moussa Benboubker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Quaternary Ammonium ◽  
Inhibitory Concentration ◽  
Hospital Environment ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Background. The microbiological risk of the hospital environment, including inert surfaces, medical devices, and equipment, represents a real problem. Objective. This study is aimed at demonstrating and assessing the antibacterial activity of three synthetic disinfectants classified as quaternary ammoniums on different bacterial strains (Gram-negative and Gram-positive like Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus) isolated from the hospital environment. The reference strains included Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853 used as negative control strains. Method. Three quaternary ammonium disinfectants were tested: DDN9® (0.5%) which contains didecylmethylpolyoxyethylammonium propionate as an active substance, spray (0.4%) containing quaternary ammonium compounds, and Phagosurf ND® (0.4%) with didecyldimethylammonium chloride. Their effect was evaluated using the disk diffusion technique and the broth dilution methods, allowing the Minimum Inhibitory Concentration (MIC) and then the Minimum Bactericidal Concentration (MBC). Result. Only the growth of Gram-positive bacteria and some strains of Gram-negative bacteria were inhibited by the three synthetic disinfectants. NDD9® demonstrated an antibacterial effect only against the Gram-positive strains (S. aureus and S. aureus ATCC 29213) with a MIC of 0.25 mg/ml. The disinfectant spray showed effect against all four strains including E. coli (9), S. aureus, E. coli ATCC 25922, and P. aeruginosa ATCC 27853 with an inhibitory concentration of 4 mg/ml, while the growth of S. aureus ATCC 29213 was inhibited at 2 mg/ml. The third disinfectant, Phagosurf ND®, inhibited only the growth of S. aureus ATCC 29213 at a MIC of 4 mg/ml. Conclusion. This study is the first here in Morocco to evaluate the bacterial activity of products intended for the control of the healthcare environment. The results obtained on the three disinfectants tested reveal an ineffectiveness against some isolated strains from the hospital environment.

scholarly journals Synthesis and Study of New Quinolineaminoethanols as Anti-Bacterial Drugs

2019 ◽  
Vol 12 (2) ◽  
pp. 91
Author(s):  
Laumaillé ◽  
Dassonville-Klimpt ◽  
Peltier ◽  
Mullié ◽  
Andréjak ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria ◽  
Escherichia Coli Bacteria

The lack of antibiotics with a novel mode of action associated with the spread of drug resistant bacteria make the fight against infectious diseases particularly challenging. A quinoline core is found in several anti-infectious drugs, such as mefloquine and bedaquiline. Two main objectives were set in this work. Firstly, we evaluated the anti-mycobacterial properties of the previous quinolines 3, which have been identified as good candidates against ESKAPEE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli) bacteria. Secondly, a new series 4 was designed and assessed against the same bacteria strains, taking the pair of enantiomers 3m/3n as the lead. More than twenty compounds 4 were prepared through a five-step asymmetric synthesis with good enantiomeric excesses (>90%). Interestingly, all compounds of series 3 were efficient on M. avium with MIC = 2–16 µg/mL, while series 4 was less active. Both series 3 and 4 were generally more active than mefloquine against the ESKAPEE bacteria. The quinolines 4 were either active against Gram-positive bacteria (MIC ≤ 4 µg/mL for 4c–4h and 4k/4l) or E. coli (MIC = 32–64 µg/mL for 4q–4v) according to the global lipophilicity of these compounds.

scholarly journals MICROBIOLOGICAL SCREENING OF OTORRHOEA FROM PEOPLE COMING TO HOSPITAL IN MAHAJANGA

2020 ◽  
pp. 25-28
Author(s):  
Rivo RAKOTOMALALA ◽  
Patrick RANDRIANANDRAINA ◽  
Tsiriniaina RAMAVOSON ◽  
Fiacre RAMISARIMANANA ◽  
Ainamalala Catherine RAZAFINDRAKOTO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
The Other ◽  
Coagulase Negative Staphylococcus ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Ear Infections ◽  
Corynebacterium Sp ◽  
Gram Positive Cocci

In whole, 56 patients were included. Amidst identified microorganisms were fungus (4,7%) and bacteria (95,3%) to which Gram negative bacilli represented 72,1% (n=44), Gram positive cocci 6,4% (n=10), Gram positive bacilli 8,2% (n=5) and Gram negative cocci 3,3% (n=2). Among these bacterias, Pseudomonas aeruginosa and Proteus sp were predominant, with respectively 41% (n=25), 23% (n=14). However, three cases of S. aureus reported, six with negative coagulase Staphylococcus, one with Escherichia coli, one with Klebsiella sp, one with Haemophilus sp, two cases with Neisseria sp and four cases with Corynebacterium sp. Two types of cultures were noticed, one of them monomorphic (91,1%, n=51) and the other polymorphic (8,9%, n=5) to which 3 associations of P. aeruginosa-Proteus sp, 1 association of P. aeruginosa- coagulase negative Staphylococcus and 1 association of P. aeruginosa- E. coli. No resistance to ciprofloxacin was observed with Pseudomonas, Neisseria sp, Haemophilus, and enterobacteria except for E. coli. No resistance to rifampicin was observed with S. aureus. However, the sensitivity of S. aureus to ciprofloxacin decreased (one bacterium out of three). The use of rifampicin or fluoroquinolones should be based on the type of ear infections,

Postantibiotic Effects of Gatifloxacin against Gram-Positive and -Negative Organisms

1999 ◽  
Vol 43 (10) ◽  
pp. 2574-2575 ◽  
Author(s):  
G. A. Pankuch ◽  
M. R. Jacobs ◽  
P. C. Appelbaum
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Gram Positive ◽  
E Coli

ABSTRACT Gatifloxacin pneumococcal, staphylococcal and enterococcal postantibiotic effects (PAEs) were 0.5 to 4.0 h, respectively. ForEscherichia coli and Pseudomonas aeruginosa, PAEs were 2.2 to 4.8 h. Pneumococcal, staphylococcal, and enterococcal postantibiotic sub-MIC effects (PA-SMEs) (four times the MICs) were 3.7 to 8.6, 2.3 to 3.8, and 1.6 h, respectively, andE. coli and P. aeruginosa PA-SMEs were ≥9.6 and 4.4 h, respectively.

Bioactive compounds isolated from submerged fermentations of the Chilean fungus Stereum rameale

2015 ◽  
Vol 70 (3-4) ◽  
pp. 97-102 ◽  
Author(s):  
Pedro Aqueveque ◽  
Carlos Leonardo Céspedes ◽  
José Becerra ◽  
Marcelo Dávila ◽  
Olov Sterner
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Bioactive Metabolites ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bioassay Guided Fractionation

Abstract Liquid fermentations of the fungus Stereum rameale (N° 2511) yielded extracts with antibacterial activity. The antibacterial activity reached its peak after 216 h of stirring. Bioassay-guided fractionation methods were employed for the isolation of the bioactive metabolites. Three known compounds were identified: MS-3 (1), vibralactone (2) and vibralactone B (3). The three compounds showed antibacterial activity as a function of their concentration. Minimal bactericidal concentrations (MBC) of compound 1 against Gram-positive bacteria were as follows: Bacillus cereus (50 μg/mL), Bacillus subtilis (10 μg/mL) and Staphylococcus aureus (100 μg/mL). Compounds 2 and 3 were active only against Gram-negative bacteria. The MBC of compound 2 against Escherichia coli was 200 μg/mL. Compound 3 inhibited significantly the growth of E. coli and Pseudomonas aeruginosa, with MBC values of 50 and 100 μg/mL, respectively.

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