Evaluation of antimicrobial compounds to inhibit growth of select Gram-positive pathogenic or antimicrobial resistant bacteria in air-exposed silage

2021 ◽  
pp. 1-10
Author(s):  
Marina Ontiveros-Magadan ◽  
Robin C. Anderson ◽  
Oscar Ruiz-Barrera ◽  
Claudio Arzola-Alvarez ◽  
Jaime Salinas-Chavira ◽  
...  
Keyword(s):  
Antimicrobial Activities ◽  
Corn Silage ◽  
Resistant Bacteria ◽  
Antimicrobial Compounds ◽  
Bacterial Cultures ◽  
Whole Plant ◽  
Colony Forming Units ◽  
Pure Cultures ◽  
Carry Over ◽  
Yeasts And Molds

Spoiled silages can harbor pathogenic and antimicrobial-resistant microbes. The potential of some antimicrobial additives to inhibit certain pathogenic and antimicrobial-resistant bacteria in air-exposed silage was measured using pure and mixed bacterial cultures. With pure cultures, laurate and monolaurin (5 mg·mL−1) caused decreases (P < 0.05) of 4 to >7 log10 colony-forming units (CFU)·mL−1 in Listeria monocytogenes and Enterococcus faecalis compared to controls. Ten-fold higher amounts of these inhibitors were needed to equivalently decrease staphylococci. 2-Nitropropanol (1 mg·mL−1) decreased (P < 0.05) E. faecalis and L. monocytogenes 2.9–3.8 and 2.4–7.2 log10 CFU·mL−1 after 6 and 24 h incubations, respectively. In air-exposed whole-plant corn silage the inhibitors caused decreases, although not necessarily significant, of 0.7–2.2 log10 CFU·mL−1 in L. monocytogenes, staphylococci and culturable aerobes after 24 h incubation, with modest yet significant (P < 0.05) inhibition (<0.1–0.3 log10 CFU·mL−1) of yeasts and molds. Tests for carry-over effects against ruminal microbes revealed laurate, monolaurin, and 2-nitropropanol inhibited methanogenesis by >50% (P < 0.05) after 24 h incubation and inhibited L. monocytogenes and enterococci. The antimicrobial activities exhibited by these compounds may yield opportunities to optimize their use to rescue spoiled silages.

EPS production and bioremoval of heavy metals by mixed and pure bacterial cultures isolated from Ankara Stream

2015 ◽  
Vol 72 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
Nur Koçberber Kiliç ◽  
Güliz Kürkçü ◽  
Durna Kumruoğlu ◽  
Gönül Dönmez
Keyword(s):  
Heavy Metal ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Mixed Cultures ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Bacterial Cultures ◽  
Removal Capacity ◽  
Pure Cultures ◽  
Pure Bacterial Cultures

This study is focused on isolation of Ni(II), Cu(II) and Cr(VI) resistant bacteria to assess their exopolysaccharide (EPS) production and related bioremoval capacities. Mixed cultures had higher heavy metal removal capacity in media with molasses (MAS) than the control cultures lacking this carbon (AS) containing 50 mg/l of heavy metal. The yields were 32%, 75.7%, and 51.1% in MAS, while the corresponding values were 29%, 55.1%, and 34.5% in AS, respectively. Purification of the strains 1, 5 and 6 present in the mixed cultures decreased the bioremoval capacities of the mixed culture samples, although these strains produced higher EPS amounts in MAS agar. Strain 5 had the highest Cu(II) (69.1%) and Cr(VI) (43.1%) removal rates at 25 mg/l initial concentration of each pollutant with EPS amounts of 0.74 g/l and 1.05 g/l, respectively. This strain was identified as Stenotrophomonas maltophilia. The presented data show that especially mixed and also pure cultures of bacterial strains isolated from Ankara Stream could be assessed as potential bioremoval agents in the treatment of Cu(II) or Cr(VI) containing wastewaters.

scholarly journals Extremophilic actinomycetes isolated from soil in Kazakhstan: Classification and antimicrobial activities

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ainur Zhulamanova ◽  
Zhanat Koshenov ◽  
Saikal Shamkeeva ◽  
Zhannur Markhametova ◽  
Diyora Abdukhakimova ◽  
...  
Keyword(s):  
Extreme Environment ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antimicrobial Compounds ◽  
Antimicrobial Compound ◽  
Future Studies ◽  
Drug Resistant Bacteria ◽  
Modified Media ◽  
Novel Agent

Extremophilic actinomycetes species are capable of surviving in extreme environment and producing antibiotics. In this study, we hypothesize that extremophiles produce antimicrobial compounds that are potentially novel agent(s) effective against drug resistant pathogens. The goal of this study is to test inhibitory activity of the extracts derived from extremophilic actinomycetes species against the most prevalent drug-resistant bacteria in Kazakhstani hospitals, and preliminarily analyze chemical composition of the active extracts. Actinomycetes species isolated from the soil of Kazakhstan were cultured in modified media mimicking extreme environment the species were isolated from. Antimicrobial compound(s) extracted with organic solvent were tested against conditionally pathogenic and multi-drug resistant pathogens Acinetobacter baumanni and Pseudomonas aeruginosa. Our study generated promising results regarding the potential discovery of novel components effective against drug resistant pathogens. Future studies will focus on further chemical analysis to identify the active component within these extremophilic extracts.

scholarly journals Isolation, Characterization, and Antimicrobial Activity of Bacterial and Fungal Representatives Associated With Particulate Matter During Haze and Non-haze Days

2022 ◽  
Vol 12 ◽  
Author(s):  
Dong Yan ◽  
Tao Zhang ◽  
Jing-Lin Bai ◽  
Jing Su ◽  
Li-Li Zhao ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Particulate Matter ◽  
Human Health ◽  
Antimicrobial Activities ◽  
Industrial Countries ◽  
Colony Forming Units ◽  
Microbial Resources ◽  
Pure Cultures ◽  
Bacteria And Fungi ◽  
Haze Days

Particulate matter (PM) has been a threat to the environment and public health in the metropolises of developing industrial countries such as Beijing. The microorganisms associated with PM have an impact on human health if they are exposed to the respiratory tract persistently. There are few reports on the microbial resources collected from PM and their antimicrobial activities. In this study, we greatly expanded the diversity of available commensal organisms by collecting 1,258 bacterial and 456 fungal isolates from 63 PM samples. A total of 77 bacterial genera and 35 fungal genera were included in our pure cultures, with Bacillus as the most prevalent cultured bacterial genus, Aspergillus, and Penicillium as the most prevalent fungal ones. During heavy-haze days, the numbers of colony-forming units (CFUs) and isolates of bacteria and fungi were decreased. Bacillus, Paenibacillus, and Chaetomium were found to be enriched during haze days, while Kocuria, Microbacterium, and Penicillium were found to be enriched during non-haze days. Antimicrobial activity against common pathogens have been found in 40 bacterial representatives and 1 fungal representative. The collection of airborne strains will provide a basis to greatly increase our understanding of the relationship between bacteria and fungi associated with PM and human health.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

scholarly journals Comparison of a Short Linear Antimicrobial Peptide with Its Disulfide-Cyclized and Cyclotide-Grafted Variants against Clinically Relevant Pathogens

2021 ◽  
Vol 9 (6) ◽  
pp. 1249
Author(s):  
Johannes Koehbach ◽  
Jurnorain Gani ◽  
Kai Hilpert ◽  
David J Craik
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Human Serum ◽  
World Health ◽  
Resistant Bacteria ◽  
Moderate Activity ◽  
Antimicrobial Compounds ◽  
Strong Activity ◽  
Linear Peptide ◽  
Linear Version

According to the World Health Organization (WHO) the development of resistance against antibiotics by microbes is one of the most pressing health concerns. The situation will intensify since only a few pharmacological companies are currently developing novel antimicrobial compounds. Discovery and development of novel antimicrobial compounds with new modes of action are urgently needed. Antimicrobial peptides (AMPs) are known to be able to kill multidrug-resistant bacteria and, therefore, of interest to be developed into antimicrobial drugs. Proteolytic stability and toxicities of these peptides are challenges to overcome, and one strategy frequently used to address stability is cyclization. Here we introduced a disulfide-bond to cyclize a potent and nontoxic 9mer peptide and, in addition, as a proof-of-concept study, grafted this peptide into loop 6 of the cyclotide MCoTI-II. This is the first time an antimicrobial peptide has been successfully grafted onto the cyclotide scaffold. The disulfide-cyclized and grafted cyclotide showed moderate activity in broth and strong activity in 1/5 broth against clinically relevant resistant pathogens. The linear peptide showed superior activity in both conditions. The half-life time in 100% human serum was determined, for the linear peptide, to be 13 min, for the simple disulfide-cyclized peptide, 9 min, and, for the grafted cyclotide 7 h 15 min. The addition of 10% human serum led to a loss of antimicrobial activity for the different organisms, ranging from 1 to >8-fold for the cyclotide. For the disulfide-cyclized version and the linear version, activity also dropped to different degrees, 2 to 18-fold, and 1 to 30-fold respectively. Despite the massive difference in stability, the linear peptide still showed superior antimicrobial activity. The cyclotide and the disulfide-cyclized version demonstrated a slower bactericidal effect than the linear version. All three peptides were stable at high and low pH, and had very low hemolytic and cytotoxic activity.

scholarly journals Bacterial Succession Pattern during the Fermentation Process in Whole-Plant Corn Silage Processed in Different Geographical Areas of Northern China

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 900
Author(s):  
Chao Wang ◽  
Hongyan Han ◽  
Lin Sun ◽  
Na Na ◽  
Haiwen Xu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Bacterial Community ◽  
Inner Mongolia ◽  
Northern China ◽  
Ammonia Nitrogen ◽  
Corn Silage ◽  
Shanxi Province ◽  
Whole Plant ◽  
Bacterial Succession ◽  
Fermentation Quality

Whole-plant corn silage is a predominant forage for livestock that is processed in Heilongjiang province (Daqing city and Longjiang county), Inner Mongolia Autonomous Region (Helin county and Tumet Left Banner) and Shanxi province (Taigu and Shanyin counties) of North China; it was sampled at 0, 5, 14, 45 and 90 days after ensiling. Bacterial community and fermentation quality were analysed. During fermentation, the pH was reduced to below 4.0, lactic acid increased to above 73 g/kg DM (p < 0.05) and Lactobacillus dominated the bacterial community and had a reducing abundance after 14 days. In the final silages, butyric acid was not detected, and the contents of acetic acid and ammonia nitrogen were below 35 g/kg DM and 100 g/kg total nitrogen, respectively. Compared with silages from Heilongjiang and Inner Mongolia, silages from Shanxi contained less Lactobacillus and more Leuconostoc (p < 0.05), and had a separating bacterial community from 14 to 90 days. Lactobacillus was negatively correlated with pH in all the silages (p < 0.05), and positively correlated with lactic and acetic acid in silages from Heilongjiang and Inner Mongolia (p < 0.05). The results show that the final silages had satisfactory fermentation quality. During the ensilage process, silages from Heilongjiang and Inner Mongolia had similar bacterial-succession patterns; the activity of Lactobacillus formed and maintained good fermentation quality in whole-plant corn silage.

Survey of mean particle length in whole-plant corn silage

2017 ◽  
Vol 33 (6) ◽  
pp. 708-715
Author(s):  
G.G.S. Salvati ◽  
L.F. Ferraretto ◽  
G.S. Dias Júnior ◽  
F.L. Drago ◽  
R.D. Shaver
Keyword(s):  
Corn Silage ◽  
Whole Plant ◽  
Particle Length

scholarly journals The Design of Alapropoginine, a Novel Conjugated Ultrashort Antimicrobial Peptide with Potent Synergistic Antimicrobial Activity in Combination with Conventional Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish
Keyword(s):  
Antimicrobial Activity ◽  
Hemolytic Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Human Red Blood Cells ◽  
Drug Resistant Bacteria ◽  
Different Strains ◽  
Conventional Antibiotics

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.

Stage of maturity, processing, and hybrid effects on ruminal in situ disappearance of whole-plant corn silage

2000 ◽  
Vol 86 (1-2) ◽  
pp. 83-94 ◽  
Author(s):  
M.A Bal ◽  
R.D Shaver ◽  
K.J Shinners ◽  
J.G Coors ◽  
J.G Lauer ◽  
...  
Keyword(s):  
Corn Silage ◽  
Whole Plant

scholarly journals Highlighting the Biotechnological Potential of Deep Oceanic Crust Fungi through the Prism of Their Antimicrobial Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Oceanic Crust ◽  
Gene Clusters ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Human Pathogens ◽  
Biotechnological Potential ◽  
Fungal Isolates

Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.

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