Bactericidal activity of disinfectants

Author(s):  
S. B. Lysko ◽  
M. V. Zadorozhnaya ◽  
O. A. Suntsova

The modern market of drugs off ers a wide range of disinfectants. However, the constant use of the same drugs contributes to the development of resistance in the microfl ora and reduces the quality of activities. In this regard to develop eff ective measures to combat and prevent infectious diseases, it is necessary to periodically monitor the activity of disinfectants used in the enterprise. The purpose of the researches was to study the bactericidal eff ect of disinfectants on the microfl ora of poultry enterprises. The researches have been carried out at the Siberian Scientifi c and Research Institute of Poultry Farming – a branch of the Federal State Budgetary Scientifi c Institution “Omsk Agrarian Scientifi c Center”. The activity of 8 disinfectants to 37 test cultures isolated from poultry farms of diff erent productivity trends and species of poultry (chickens, turkeys, quails) has been tested. It has been found as a result of the conducted research that the most expressed bactericidal eff ect on gram-positive and gram-negative microorganisms were complex disinfectants, which included glutaraldehyde in combination with quaternary ammonium compounds. Thus, 1 % solutions of Gludesive and Viroshield provided the death of all test cultures, Dinovis Ultra and TN-4+ – 92 and 84 % of cultures. The disinfecting activity of Mirosan drug and formalin was most expressed for gram-positive microfl ora, among gram-negative microfl ora resistance was registered in 25–75 % and 25–50 % of cultures, respectively. Drugs EcoSide Advansa and Ecocide C have showed the lowest activity to all investigated microorganisms. The largest number of resistant cultures to the tested disinfectants have been registered in the bacteria of the genus Citrobacter spp. and Pseudomonas aeruginosa, while simultaneously noted resistance to 4–6 drugs.

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 367 ◽  
Author(s):  
Yuguang Liu ◽  
Dirk Schulze-Makuch ◽  
Jean-Pierre de Vera ◽  
Charles Cockell ◽  
Thomas Leya ◽  
...  

Single-cell sequencing is a powerful technology that provides the capability of analyzing a single cell within a population. This technology is mostly coupled with microfluidic systems for controlled cell manipulation and precise fluid handling to shed light on the genomes of a wide range of cells. So far, single-cell sequencing has been focused mostly on human cells due to the ease of lysing the cells for genome amplification. The major challenges that bacterial species pose to genome amplification from single cells include the rigid bacterial cell walls and the need for an effective lysis protocol compatible with microfluidic platforms. In this work, we present a lysis protocol that can be used to extract genomic DNA from both gram-positive and gram-negative species without interfering with the amplification chemistry. Corynebacterium glutamicum was chosen as a typical gram-positive model and Nostoc sp. as a gram-negative model due to major challenges reported in previous studies. Our protocol is based on thermal and chemical lysis. We consider 80% of single-cell replicates that lead to >5 ng DNA after amplification as successful attempts. The protocol was directly applied to Gloeocapsa sp. and the single cells of the eukaryotic Sphaerocystis sp. and achieved a 100% success rate.


1987 ◽  
Vol 99 (2) ◽  
pp. 439-443 ◽  
Author(s):  
P. R. Hunter ◽  
S. H. Burge

SUMMARYFifty-eight bottles of natural mineral water, taken from the point of sale, were bacteriologically examined. No coliforms orAeromonas sp.were isolated from any sample. High total bacterial counts were found particularly in the still waters. Most of the organisms isolated in the total counts were Gram-negative rods, but Gram-positive organisms were also isolated. Gram-positive cocci were further identified, some of which were known human commensals suggesting contamination of the waters prior to bottling.


2019 ◽  
Vol 21 (3) ◽  
pp. 1098-1114 ◽  
Author(s):  
Chia-Ru Chung ◽  
Ting-Rung Kuo ◽  
Li-Ching Wu ◽  
Tzong-Yi Lee ◽  
Jorng-Tzong Horng

Abstract In recent years, antimicrobial peptides (AMPs) have become an emerging area of focus when developing therapeutics hot spot residues of proteins are dominant against infections. Importantly, AMPs are produced by virtually all known living organisms and are able to target a wide range of pathogenic microorganisms, including viruses, parasites, bacteria and fungi. Although several studies have proposed different machine learning methods to predict peptides as being AMPs, most do not consider the diversity of AMP activities. On this basis, we specifically investigated the sequence features of AMPs with a range of functional activities, including anti-parasitic, anti-viral, anti-cancer and anti-fungal activities and those that target mammals, Gram-positive and Gram-negative bacteria. A new scheme is proposed to systematically characterize and identify AMPs and their functional activities. The 1st stage of the proposed approach is to identify the AMPs, while the 2nd involves further characterization of their functional activities. Sequential forward selection was employed to extract potentially informative features that are possibly associated with the functional activities of the AMPs. These features include hydrophobicity, the normalized van der Waals volume, polarity, charge and solvent accessibility—all of which are essential attributes in classifying between AMPs and non-AMPs. The results revealed the 1st stage AMP classifier was able to achieve an area under the receiver operating characteristic curve (AUC) value of 0.9894. During the 2nd stage, we found pseudo amino acid composition to be an informative attribute when differentiating between AMPs in terms of their functional activities. The independent testing results demonstrated that the AUCs of the multi-class models were 0.7773, 0.9404, 0.8231, 0.8578, 0.8648, 0.8745 and 0.8672 for anti-parasitic, anti-viral, anti-cancer, anti-fungal AMPs and those that target mammals, Gram-positive and Gram-negative bacteria, respectively. The proposed scheme helps facilitate biological experiments related to the functional analysis of AMPs. Additionally, it was implemented as a user-friendly web server (AMPfun, http://fdblab.csie.ncu.edu.tw/AMPfun/index.html) that allows individuals to explore the antimicrobial functions of peptides of interest.


Author(s):  
Youzhou Liu ◽  
Chen Dai ◽  
Yaqiu Zhou ◽  
Junqing Qiao ◽  
Bao Tang ◽  
...  

Pseudomonas chlororaphis YL-1 has extensive antimicrobial activities against phytopathogens, and its genome harbors pyoverdine (PVD) biosynthesis gene cluster. The alternative sigma factor PvdS in Pseudomonas aeruginosa PAO1, acts as a critical regulator in response to iron starvation. The assembly of the PVD backbone starts with peptide synthetase enzyme PvdL. PvdF catalyzes formylation of L-OH-Orn to produce L-N5-hydroxyornithine. Here, we describe the characterization of PVD production in YL-1 and its antimicrobial activity as compared with its PVD-deficient mutants ΔpvdS, ΔpvdF, and ΔpvdL, that were obtained using a sacB-based site-specific mutagenesis strategy. Using in vitro methods, we examined the effect of exogenous iron under low-iron conditions and iron-chelating agent under iron-sufficient conditions on PVD production, antibacterial activity, and the relative expression of PVD transcription factor gene pvdS in YL-1. We found that strain YL-1, mutant ΔpvdF, and complemented strain ΔpvdS(pUCP26-pvdS) produced visible PVDs and demonstrated a wide range of inhibitory effects against Gram-negative and Gram-positive bacteria in vitro under low-iron conditions, and that with the increase of iron its PVD production and antibacterial activity were reduced. The antibacterial compounds produced by strain YL-1 in low-iron conditions were PVDs based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Moreover, the antibacterial activity observed in vitro was correlated with in vivo control efficacies of strain YL-1 against rice bacterial leaf blight (BLB) disease caused by Xanthomonas oryzae pv. oryzae (Xoo). Collectively, PVDs are responsible for the antibacterial activities of strain YL-1 under both natural and induced low-iron conditions. IMPORTANCE: The results demonstrated that PVDs are essential for the broad-spectrum antibacterial activities of strain YL-1 against both Gram-positive and Gram-negative bacteria in low-iron conditions. Our findings also highlight the effect of exogenous iron on the production of PVD and the importance of this bacterial product in bacterial interactions. As a biocontrol agent, PVDs can directly inhibit the proliferation of the tested bacteria in addition to participating in iron competition.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Himayat Ullah ◽  
Muhammad Hubaib ◽  
Muhammad Israr ◽  
Muhammad Mushtaq ◽  
Muhammad Zeeshan ◽  
...  

Every plant available in the universe is not produced to be the part of biodiversity, but is also produced to obtain medicinal purposes. The medicinal value of the plant is due to the availability of various chemical compounds [1]. Since prehistoric time, the crude extract of plant is used to cure various diseases, although the biologically active components of the plant were unidentified [2]. In the present study the antibacterial activity is performed for various extracts of cerastium glomeratum. The plant cerastium glomeratum was collected from near kalpani river Mardan, Pakistan and was identified by lecturer Israr department of botany GPGC Mardan, Pakistan. The plant was dried under shade and grinded into powder form. The extraction process was done by using soxhlet apparatus, reflux condenser and maceration process using ethanol as a solvent. The extract was divided into different fractions of n-hexane, DCM, ethyl acetate and water. These four extracts were tested against gram positive (staphylococcus aureus) and gram negative (E.coli) bacteria using well diffusion technique. The water extract show a wide range inhibition zone against both gram positive and gram negative bacteria while n-hexane, DCM and ethyl acetate fractions show no zone of inhibition against bacteria. In effort to find new antibacterial compounds cerastium glomeratum seems to be a good plant for additional phytochemical studies.


Author(s):  
Ranganathan Kapilan

Wide range of plant extracts are used for medicinal purposes as they are very cheap, efficient, harmless and do not cause any side effects. Spices are parts of different plants and they add special aroma and taste to the food preparations. The aim of the study was to determine the antimicrobial activity of some important naturally grown spices against gram positive and gram negative pathogenic bacteria. Antibacterial activity of the spices was tested against gram positive bacteria Bacillus pumilus, Bacillus cereus and Staphylococcus aureus and gram negative bacteria Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa using aqueous, ethanolic, methanolic and liquid nutrient extracts. Among all the extracts tested alcoholic extracts of Cardamom (Elettaria cardamom), clove (Eugenia caryophyllus) and lemongrass (Cymbopogoncitratus) showed maximum antimicrobial activity against gram negative bacteria while alcoholic extract of Cardamom (Elettaria cardamom) and lemongrass (Cymbopogoncitratus) showed maximum activity against gram positive bacteria. All the spices tested in this study proved that they have antibacterial activity and the maximum activity index (1.39) was exhibited by the ethanol extract of cardamom against E.coli.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Hessa H. Al-Rasheed ◽  
Essam N. Sholkamy ◽  
Monirah Al Alshaikh ◽  
Mohammed R. H. Siddiqui ◽  
Ahmed S. Al-Obaidi ◽  
...  

The present work represents the synthesis, characterization, and antimicrobial studies of novel series of 2,4-bis(hydrazino)-6-substituted-1,3,5-triazine and their Schiff base derivatives. IR, NMR (H1 and C13), elemental analysis, and LC-MS characterized the prepared compounds. The biological activity of the target products was evaluated as well. Twenty-two of the prepared compounds were selected according to their solubility in aqueous DMSO. Only eight compounds showed good activity against the selected pathogenic bacteria and did not show antagonistic effect against fungus Candida albicans. Two compounds 4k and 5g have wide-range effect presently in Gram-positive and Gram-negative bacteria while other compounds (4f, 4i, 4m, 5d, 6i, and 6h) showed specific effect against the Gram-negative or Gram-positive bacteria. The minimum inhibitory concentration (MIC, μg/mL) of 4f, 4i, 4k, and 6h compounds against Streptococcus mutans was 62.5 μg/mL, 100 μg/mL, 31.25 μg/mL, and 31.25 μg/mL, respectively. The MIC of 4m, 4k, 5d, 5g, and 6h compounds against Staphylococcus aureus was 62.5 μg/mL, 31.25 μg/mL, 31.25 μg/mL, 100 μg/mL, and 62.5 μg/mL, respectively. The MIC of 4k, 5g, and 6i compounds against Salmonella typhimurium was 31.25 μg/mL, 100 μg/mL, and 62.5 μg/mL, respectively. The MIC of 6i compound against Escherichia coli was 62.5 μg/mL.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 287 ◽  
Author(s):  
Diego Romano Perinelli ◽  
Dezemona Petrelli ◽  
Luca Agostino Vitali ◽  
Giulia Bonacucina ◽  
Marco Cespi ◽  
...  

Quaternary ammonium amphiphiles are a class of compounds with a wide range of commercial and industrial uses. In the pharmaceutical field, the most common quaternary ammonium surfactant is benzalkonium chloride (BAC), which is employed as a preservative in several topical formulations for ocular, skin, or nasal application. Despite the broad antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as fungi and small enveloped viruses, safety concerns regarding its irritant and cytotoxic effect on epithelial cells still remain. In this work, quaternary ammonium derivatives of leucine esters (C10, C12 and C14) were synthesised as BAC analogues. These cationic surfactants were characterised in terms of critical micelle concentration (CMC, by tensiometry), cytotoxicity (MTS and LDH assays on the Caco-2 and Calu-3 cell lines) and antimicrobial activity on the bacterial species Staphylococcus aureus and Enterococcus faecalis among the Gram-positives, Escherichia coli and Pseudomonas aeruginosa among the Gram-negatives and the yeast Candida albicans. They showed satisfactory surface-active properties, and a cytotoxic effect that was dependent on the length of the hydrophobic chain. Lower minimum inhibiting concentration (MIC) values were calculated for C14-derivatives, which were comparable to those calculated for BAC toward Gram-positive bacteria and slightly higher for Gram-negative bacteria and C. albicans. Thus, the synthesised leucine-based quaternary ammonium cationic surfactants can potentially find application as promising surface-active compounds with antimicrobial activity.


2019 ◽  
Vol 8 (1) ◽  
pp. 873-884 ◽  
Author(s):  
Suresh Sagadevan ◽  
Selvaraj Vennila ◽  
Preeti Singh ◽  
Jayasingh Anita Lett ◽  
Mohd Rafie Johan ◽  
...  

Abstract The bacterial communities (Gram-negative and Gram-positive) form the biofilms which oppose the mode of action of antibiotics and affecting the immune system of the human. These chronic infections related to biofilm are always hard to be cured because of their inherent resistance to both antimicrobial agents and host defense. The present study is devoted to the synthesis of silver nanoparticles (AgNPs) using aqueous extracts of Averrhoa bilimbi leaf and Plum fruit (Prunus bokharensis) and its inhibitory effect on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi. Here, AgNPs) were successfully prepared by green synthesis method obtained by the reduction of silver nitrate into silver ions. The synthesized AgNPs were characterized by UV-Vis Spectroscopy, XRD, FTIR, FESEM-EDAX and DLS analysis. The antimicrobial effects of the two extract were evaluated by the disk diffusion method. The green synthesized AgNPs exhibited good antibacterial activity against both Gram-negative and Gram-positive. They were also analyzed for their significant antibacterial activities against all the test cultures exposed whereas Escherichia coli and Salmonella typhi topped among other test cultures. The anti-proliferative activity of phytochemical mediated synthesis of Ag NPs was investigated for their cytotoxicity in Vero and Human epidermoid larynx carcinoma cell lines (HEp-2) based on their viability using MTT assay. The present study also represents the synergistic bioactivity of silver nanoparticles using in vitro models.


Author(s):  
Mohamed Rbaa ◽  
Abdelhadi Hichar ◽  
Omar Bazdi ◽  
Younes Lakhrissi ◽  
Khadija Ounine ◽  
...  

Abstract Background 8-Hydroxyquinoline derivatives are known for their extensive applications in the field of analytical chemistry and separation techniques; their complexes with transition metals also exhibit antibacterial and antifungal activity. Results In the present study, we synthesized a new series of pyranoquinoline derivatives and evaluated their antibacterial activities. The structures of the synthesized compounds were characterized by Fourier transform infrared (FT-IR), hydrogen-1 nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and elemental analysis. All the prepared compounds were evaluated in vitro as antimicrobial agents against Gram-positive and Gram-negative bacterial strains (Escherichia coli (ATCC35218), Staphylococcus aureus (ATCC29213), Vibrio parahaemolyticus (ATCC17802), and Pseudomonas aeruginosa (ATCC27853)). The screening test was determined by using the standard protocol of disc diffusion method (DDM). Conclusion We have synthesized new pyranic compounds bearing an 8-hydroxyquinoline moiety on their structure. The preliminary screening results showed that all the tested compounds have a remarkable inhibitory effect on the growth of the majority of the tested bacterial strains compared to the standard antibiotic (penicillin G), and the chlorinated compound (Q1) is more active against Gram-positive bacteria than Gram-negative bacteria such as the Staphylococcus aureus strain which is the most sensitive. Gram-positive bacteria are responsible for a wide range of infectious diseases, and rising resistance in this group is causing increasing concern. Thus, this study develops novel heterocyclic compound derivatives of 8-hydroxyquinoline that have demonstrated good antibacterial activity against Gram-positive bacteria. Graphical abstract


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