scholarly journals Study of the Effect of the Earthworm (Aporrectodea molleri) Cutaneous Excreta on Bacterial Growth

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Lamia Yakkou ◽  
Sofia Houida ◽  
Mohammed Raouane ◽  
Souad Amghar ◽  
Abdellatif El Harti
Keyword(s):  
Bacterial Growth ◽  
Growth Rates ◽  
Culture Media ◽  
Chemical Constituents ◽  
High Growth ◽  
Maximum Growth ◽  
Plant Growth Promoting Bacteria ◽  
E Coli ◽  
Conventional Medium

The effect on the bacterial growth of Aporrectodea molleri cutaneous excreta has given very satisfactory results. The cutaneous excreta were obtained using the electrical stimulation technique, recently developed by our laboratory. This technique made it possible to collect the excreta in sufficient quantities while ruling out any possible interference with the chemical constituents of the soil. The effectiveness of cutaneous excreta, tested as culture media at different concentrations on bacterial growth, was justified not only by the high growth rates but also by the concentrations used, which were several times lower than those of the conventional medium (nutrient agar). Indeed, the maximum growth rate recorded by E. coli and P. fluorescens is, respectively, 1.32 times and 2.99 times greater than that observed on the conventional medium. These higher levels are obtained at optimal excretion concentrations which are, respectively, 8 times and 133.33 times lower than the concentration of the conventional medium. The efficacy interval that delimited the excretion concentrations tested covers 8 successive concentrations ranging from 0.0075% to 1% for P. fluorescens, while for E. coli, this interval covers only three concentrations ranging from 0.06% at 0.25%. The growth rates of P. fluorescens are always higher than those of E. coli. The higher efficiency of excretions on the growth of P. fluorescens shows that this strain is more suited to use these excretions as a source of nutrients and to react positively to the stimulation of growth. These results, obtained in vitro, prove that, in the natural environment, the production of lubricating and viscous cutaneous excretions does not only have the role of facilitating the movement and digging of galleries by earthworms but also of enriching the soil in nutrients and growth factors with high added values for the activation and development of plant growth-promoting bacteria essential for soil fertility.

scholarly journals Influence of nutrient availability on in vitro growth of major bovine mastitis pathogens

2021 ◽  
Vol 88 (1) ◽  
pp. 80-88
Author(s):  
Remo Stürmlin ◽  
Josef J. Gross ◽  
Olga Wellnitz ◽  
Lea A. Wagner ◽  
Camille Monney ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Nutrient Availability ◽  
Bovine Mastitis ◽  
Milk Composition ◽  
B Vitamins ◽  
E Coli ◽  
Streptococcus Uberis ◽  
Whole Milk ◽  
Mastitis Pathogens

AbstractThe aim of the present study was to investigate the effects of milk composition changes on the in vitro growth of bovine mastitis pathogens. Nutritional requirements of three major bovine mastitis pathogens Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Streptococcus uberis (S. uberis) were investigated in vitro. We used ultra-high temperature (UHT) treated milk with different contents of fat, protein, and carbohydrates to test the influence of the availability of various milk constituents on pathogen growth characteristics. Additionally, the bacterial growth was investigated under experimentally modified nutrient availability by dilution and subsequent supplementation with individual nutrients (carbohydrates, different nitrogen sources, minerals, and different types of B vitamins) either to milk or to a conventional medium (thioglycolate broth, TB). Varying contents of fat, protein or lactose did not affect bacterial growth with the exception of growth of S. uberis being promoted in protein-enriched milk. The addition of nutrients to diluted whole milk and TB partly revealed different effects, indicating that there are media-specific growth limiting factors after dilution. Supplementation of minerals to diluted milk did not affect growth rates of all studied bacteria. Bacterial growth in diluted whole milk was decreased by the addition of high concentrations of amino acids in S. aureus, and by urea and additional B vitamins in E. coli and S. aureus. The growth rate of S. uberis was increased by the addition of B vitamins to diluted whole milk. The present results demonstrate that growth-limiting nutrients differ among pathogen types. Because reduced bacterial growth was only shown in diluted milk or TB, it is unlikely that alterations in nutrient availability occurring as a consequence of physiological changes of milk composition in the cow's udder would directly affect the susceptibility or course of bovine mastitis.

scholarly journals Impact of Different Carbon Sources on the in vitro Growth and Viability of Escherichia coli (SUBE01) and Salmonella spp. (SUBS01) Cells

2016 ◽  
pp. 39-44
Author(s):  
Ifra Tun Nur ◽  
Jannatun Tahera ◽  
Md Sakil Munna ◽  
M Majibur Rahman ◽  
Rashed Noor
Keyword(s):  
Escherichia Coli ◽  
Bacterial Growth ◽  
Culture Media ◽  
Bacterial Species ◽  
Carbon Sources ◽  
Growth Dynamics ◽  
Luria Bertani ◽  
Tween 20 ◽  
Salmonella Spp

With a previous observation of Escherichia coli growth cessation along with temperature variation within three different bacteriological culture media (nutrient agar, Luria-Bertani agar and minimal agar), current investigation further depicted on the possible growth dynamics of Escherichia coli (SUBE01) and Salmonella (SUBS01) growth and viability upon supplementation of different carbon sources (dextrose, sucrose, lactose, glycerol and tween 20) at 37°C under the aeration of 100 rpm. Viability of the tested bacterial species was assessed through the enumeration of the colony forming unit (cfu) appeared upon prescribed incubation for 12-24 hours on different agar plates consisting of the above mentioned carbon sources. Besides, to inspect the cellular phenotypic changes, morphological observations were conducted under the light microscope. Variations in bacterial growth (either growth acceleration or cessation) were further noticed through the spot tests on the agar plates. Considerable shortfalls in the culturable cells of E. coli and Salmonella spp. were noted in the minimal media separately consisting of sucrose, lactose, glycerol or tween 20 while an opposite impact of accelerated growth was noticed in the media supplied with dextrose. The data revealed a hierarchy of consequence of carbon sources as nutrient generators whereby the favourable bacterial growth and survival order of the carbon sources was estimated as dextrose > glycerol > lactose > tween 20 > sucrose.Bangladesh J Microbiol, Volume 32, Number 1-2,June-Dec 2015, pp 39-44

scholarly journals Antimicrobial efficacy of a new tri-antibiotic combination against resistant endodontic pathogens: An in-vitro study

2020 ◽  
Vol 23 (4) ◽  
pp. 8p ◽  
Author(s):  
Prasanna T. Dahake ◽  
Sudhindra M Baliga
Keyword(s):  
Root Canal ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
In Vitro Study ◽  
Vitro Study ◽  
New Combination ◽  
Antimicrobial Efficacy ◽  
E Coli ◽  
Background Removal

Background: Removal of all the pathogenic bacteria from the root canal system is of prime importance for the success of endodontic therapy. Objective: The study aimed to determine the antimicrobial efficacy of three antibiotics and their new combination against selected endodontic pathogens. Methods: In this in-vitro study, we used bacterial strains associated with the refractory endodontic condition and determined MIC and MBC of Clindamycin (C), Metronidazole (M), Doxycycline (D) as well as their combination CMD. We cultured Candida Albicans, Pseudomonas Aeruginosa, Escherichia Coli, Enterococcus Faecalis, Streptococcus Mutans, Bacillus Subtilis subsp. spizizenii, Actinomyces Actinomycetemcomitans on selective culture media. We analyzed the data using paired 't' test, one-way ANOVA, and Tuckey's HSD post hoc test. Results: Clindamycin inhibited the growth of C. Albicans (90%) and S. Mutans (90%) significantly and P. Aeruginosa, E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. Metronidazole did not inhibit any of the bacteria. Doxycycline inhibited C. Albicans (90%), P. Aeruginosa (90%), and S. Mutans (90%) significantly while E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. The combination of CMD inhibited all the microbes significantly. However, at bactericidal concentrations of CMD, E. Faecalis (p = 0.024), B. Subtilis (p = 0.021) and A. Actinomycetemcomitans (p = 0.041) were eliminated significantly, while C. Albicans (p = 0.164), P. Aeruginosa (p = 0.489), E. Coli (p = 0.106) and S. Mutans (p = 0.121) showed resistance. Conclusion: Combination CMD can be used against resistant endodontic pathogens to achieve predictable endodontic results.KEYWORDSAntimicrobial agents; Clindamycin; Doxycycline; Metronidazole; Root canal therapy.    

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

2007 ◽  
Vol 70 (3) ◽  
pp. 543-550 ◽  
Author(s):  
BYENG R. MIN ◽  
WILLIAM E. PINCHAK ◽  
ROBIN C. ANDERSON ◽  
TODD R. CALLAWAY
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
Tannin Extract ◽  
Bacterial Growth Rate ◽  
Linear Effect ◽  
E Coli

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

scholarly journals Rapid Growth of UropathogenicEscherichia coliduring Human Urinary Tract Infection

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Valerie S. Forsyth ◽  
Chelsie E. Armbruster ◽  
Sara N. Smith ◽  
Ali Pirani ◽  
A. Cody Springman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Urinary Tract ◽  
Growth Rates ◽  
High Growth ◽  
Replication Forks ◽  
Chromosomal Replication ◽  
E Coli ◽  
Tract Infections

ABSTRACTUropathogenicEscherichia coli(UPEC) strains cause most uncomplicated urinary tract infections (UTIs). These strains are a subgroup of extraintestinal pathogenicE. coli(ExPEC) strains that infect extraintestinal sites, including urinary tract, meninges, bloodstream, lungs, and surgical sites. Here, we hypothesize that UPEC isolates adapt to and grow more rapidly within the urinary tract than otherE. coliisolates and survive in that niche. To date, there has not been a reliable method available to measure their growth ratein vivo. Here we used two methods: segregation of nonreplicating plasmid pGTR902, and peak-to-trough ratio (PTR), a sequencing-based method that enumerates bacterial chromosomal replication forks present during cell division. In the murine model of UTI, UPEC strain growth was robustin vivo, matching or exceedingin vitrogrowth rates and only slowing after reaching high CFU counts at 24 and 30 h postinoculation (hpi). In contrast, asymptomatic bacteriuria (ABU) strains tended to maintain high growth ratesin vivoat 6, 24, and 30 hpi, and population densities did not increase, suggesting that host responses or elimination limited population growth. Fecal strains displayed moderate growth rates at 6 hpi but did not survive to later times. By PTR,E. coliin urine of human patients with UTIs displayed extraordinarily rapid growth during active infection, with a mean doubling time of 22.4 min. Thus, in addition to traditional virulence determinants, including adhesins, toxins, iron acquisition, and motility, very high growth ratesin vivoand resistance to the innate immune response appear to be critical phenotypes of UPEC strains.IMPORTANCEUropathogenicEscherichia coli(UPEC) strains cause most urinary tract infections in otherwise healthy women. While we understand numerous virulence factors are utilized byE. colito colonize and persist within the urinary tract, these properties are inconsequential unless bacteria can divide rapidly and survive the host immune response. To determine the contribution of growth rate to successful colonization and persistence, we employed two methods: one involving the segregation of a nonreplicating plasmid in bacteria as they divide and the peak-to-trough ratio, a sequencing-based method that enumerates chromosomal replication forks present during cell division. We found that UPEC strains divide extraordinarily rapidly during human UTIs. These techniques will be broadly applicable to measurein vivogrowth rates of other bacterial pathogens during host colonization.

scholarly journals Lipocalin 2: A New Antimicrobial in Mast Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2380 ◽  
Author(s):  
Yu-Ling Chang ◽  
Zhenping Wang ◽  
Satomi Igawa ◽  
Jae Eun Choi ◽  
Tyler Werbel ◽  
...  
Keyword(s):  
Mast Cells ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Bacterial Growth ◽  
Immune Defense ◽  
Lipocalin 2 ◽  
Vitro Assay ◽  
E Coli ◽  
Sphingosine 1 Phosphate

Mast cells (MCs) play a significant role in the innate immune defense against bacterial infection through the release of cytokines and antimicrobial peptides. However, their antimicrobial function is still only partially described. We therefore hypothesized that MCs express additional antimicrobial peptides. In this study, we used FANTOM 5 transcriptome data to identify for the first time that MCs express lipocalin 2 (LCN2), a known inhibitor of bacterial growth. Using MCs derived from mice which were deficient in LCN2, we showed that this antimicrobial peptide is an important component of the MCs’ antimicrobial activity against Escherichia coli (E. coli). Since sphingosine-1-phosphate receptors (S1PRs) on MCs are known to regulate their function during infections, we hypothesized that S1P could activate LCN2 production in MCs. Using an in vitro assay, we demonstrated that S1P enhances MCs antimicrobial peptide production and increases the capacity of MCs to directly kill S. aureus and E. coli via an LCN2 release. In conclusion, we showed that LCN2 is expressed by MCs and plays a role in their capacity to inhibit bacterial growth.

scholarly journals Adaptation in a Mouse Colony Monoassociated with Escherichia coli K-12 for More than 1,000 Days

2010 ◽  
Vol 76 (14) ◽  
pp. 4655-4663 ◽  
Author(s):  
Sean M. Lee ◽  
Aaron Wyse ◽  
Aaron Lesher ◽  
Mary Lou Everett ◽  
Linda Lou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rates ◽  
Bacterial Species ◽  
Intestinal Flora ◽  
Average Density ◽  
Host Bacterium ◽  
E Coli ◽  
K 12

ABSTRACT Although mice associated with a single bacterial species have been used to provide a simple model for analysis of host-bacteria relationships, bacteria have been shown to display adaptability when grown in a variety of novel environments. In this study, changes associated with the host-bacterium relationship in mice monoassociated with Escherichia coli K-12 over a period of 1,031 days were evaluated. After 80 days, phenotypic diversification of E. coli was observed, with the colonizing bacteria having a broader distribution of growth rates in the laboratory than the parent E. coli. After 1,031 days, which included three generations of mice and an estimated 20,000 generations of E. coli, the initially homogeneous bacteria colonizing the mice had evolved to have widely different growth rates on agar, a potential decrease in tendency for spontaneous lysis in vivo, and an increased tendency for spontaneous lysis in vitro. Importantly, mice at the end of the experiment were colonized at an average density of bacteria that was more than 3-fold greater than mice colonized on day 80. Evaluation of selected isolates on day 1,031 revealed unique restriction endonuclease patterns and differences between isolates in expression of more than 10% of the proteins identified by two-dimensional electrophoresis, suggesting complex changes underlying the evolution of diversity during the experiment. These results suggest that monoassociated mice might be used as a tool for characterizing niches occupied by the intestinal flora and potentially as a method of targeting the evolution of bacteria for applications in biotechnology.

scholarly journals In Vitro Antimicrobial Activity of an Experimental Dentifrice Based on Ricinus Communis

2014 ◽  
Vol 25 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Vanessa Maria Fagundes Leite ◽  
Juliana Barchelli Pinheiro ◽  
Marina Xavier Pisani ◽  
Evandro Watanabe ◽  
Raphael Freitas de Souza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Growth Inhibition ◽  
Bacterial Growth ◽  
Ricinus Communis ◽  
Candida Spp ◽  
E Coli ◽  
Reflected Light ◽  
Bacterial Growth Inhibition ◽  
Post Hoc

This study evaluated the antimicrobial activity of a Ricinus communis-based experimental dentifrice for denture hygiene against the following standard strains: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans and Candida glabrata. The minimum inhibitory concentration (MIC) assay was performed with R. communis in pure oil at 2.5%. Only E. coli was not inhibited by R. communis, but the MIC (0.0781%) was effective against the other microorganisms. From these results it was determined the R. communis concentrations for experimental dentifrices, 1, 2, 5 and 10%, which were evaluated by the test-well diffusion in agar. The commercial dentifrices Colgate, Trihydral and Corega Brite were tested for comparative purposes. The diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a rule under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (α=0.05). Neither the commercial nor the experimental dentifrices were effective against E. coli. The experimental dentifrices containing R. communis at 2, 5 and 10% presented action against S. mutans, S. aureaus and E. faecallis. The experimental dentifrices showed no antimicrobial activity against Candida spp. and E. coli in any of the tested concentrations. Trihydral was the most effective. Comparing the experimental dentifrices, the product with 10% R. communis produced the largest zones of bacterial growth inhibition and had similar antimicrobial activity to the commercial dentifrices, except against S. aureus.

Persistent bloody diarrhoea without fever associated with diffusely adherent Escherichia coli in a young child

2013 ◽  
Vol 62 (12) ◽  
pp. 1907-1910 ◽  
Author(s):  
Sandra Patzi-Vargas ◽  
Mussaret Zaidi ◽  
Rodolfo Bernal-Reynaga ◽  
Magda León-Cen ◽  
Alba Michel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Culture Media ◽  
Evidence Base ◽  
Antimicrobial Treatment ◽  
Molecular Techniques ◽  
Bloody Diarrhoea ◽  
Severe Diarrhoea ◽  
E Coli ◽  
Clinical Laboratories

Diffusely adherent Escherichia coli (DAEC) is thought to cause diarrhoea in children, and so too are other diarrhoeagenic E. coli (DEC); however, the evidence base is inconclusive. DEC pathotypes are differentiated on the basis of their pathogenic features, and thus cannot be quickly identified on selective culture media. Molecular techniques, not readily available in most clinical laboratories, are required to differentiate DEC strains from non-pathogenic E. coli in the stool flora. We report a case of persistent bloody diarrhoea, without fever, in a previously healthy 21-month infant from whom we isolated five DAEC strains. The child’s stools movements were loose, with gross blood and mucus; fresh mount analysis revealed numerous faecal leukocytes and erythrocytes. Response to antimicrobial treatment with trimethoprim-sulfamethoxazole was poor despite susceptibility in vitro. Although the patient improved with azithromycin, blood was present in the patient’s stools for over 30 days. The severe diarrhoea in this patient might be explained by the fact that these DAEC isolates harboured a siderophore receptor, which allows the bacteria to use iron derived from haem compounds that promote its multiplication. The isolates also induced in vitro secretion of several immunomodulatory cytokines that may account for the patient’s loose stools and faecal leukocytes. DAEC may play a greater role than suspected in afebrile children with bloody diarrhoea.

scholarly journals Antimicrobial Effects of Equine Platelet Lysate

2021 ◽  
Vol 8 ◽  
Author(s):  
Julie Gordon ◽  
Sonsiray Álvarez-Narváez ◽  
John F. Peroni
Keyword(s):  
Bacterial Growth ◽  
Antimicrobial Properties ◽  
Normal Growth ◽  
Platelet Lysate ◽  
Resistant Bacteria ◽  
Growth Media ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
E Coli

The development of antimicrobial resistant bacteria and the lack of novel antibiotic strategies to combat those bacteria is an ever-present problem in both veterinary and human medicine. The goal of this study is to evaluate platelet lysate (PL) as a biological alternative antimicrobial product. Platelet lysate is an acellular platelet-derived product rich in growth factors and cytokines that is manufactured via plateletpheresis and pooled from donor horses. In the current study, we sought to define the antimicrobial properties of PL on select gram-positive and gram-negative bacteria. Results from an end-point in vitro assay showed that PL did not support bacterial growth, and in fact significantly reduced bacterial content compared to normal growth media. An in vitro assay was then utilized to further determine the effects on bacterial growth dynamics and showed that all strains exhibited a slower growth rate and lower yield in the presence of PL. The specific effects of PL were unique for each bacterial strain: E. coli and P. aeruginosa growth was affected in a concentration-dependent manner, such that higher amounts of PL had a greater effect, while this was not true for S. aureus or E. faecalis. Furthermore, the onset of exponential growth was delayed for E. coli and P. aeruginosa in the presence of PL, which has significant clinical implications for developing a dosing schedule. In conclusion, our findings demonstrate the potential value of PL as a broad-spectrum antimicrobial that would offer an alternative to traditional antibiotics for the treatment of bacterial infection in equine species.

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