scholarly journals Effects of Incubation Time and Inoculation Level on the Stabilities of Bacteriostatic and Bactericidal Antibiotics against Salmonella Typhimurium

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1019
Author(s):  
Nana Nguefang Laure ◽  
Jirapat Dawan ◽  
Juhee Ahn
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Typhimurium ◽  
Incubation Time ◽  
Antimicrobial Activities ◽  
Inoculum Level ◽  
Antibiotic Resistant ◽  
Inoculum Effect ◽  
Practical Information ◽  
Inoculation Time ◽  
The Stability

This study was designed to evaluate the stability of chloramphenicol, erythromycin, tetracycline, cephalothin, ciprofloxacin, and tobramycin against antibiotic-sensitive Salmonella Typhimurium (ASST) and antibiotic-resistant S. Typhimurium (ARST) during the broth microdilution assay. The antimicrobial activity in association with antibiotic stability was measured by using antibiotic susceptibility, time-delayed inoculation, time-extended incubation, and inoculum effect assays. The loss of the antimicrobial activity of cephalothin against ASST exposed to 1 MIC was observed for the 10 h delayed inoculation. The antimicrobial activities of tetracycline and ciprofloxacin against ASST and ARST exposed to ½ MIC were significantly decreased after the 10 h delayed inoculation. All antibiotics used in this study, except for ciprofloxacin, showed the considerable losses of antimicrobial activities against ASST and ARST after 40 h of incubation at 37 °C when compared to the 20 h of incubation during AST. Compared to the standard inoculum level (6 log CFU/mL), the MIC0.1 values of bactericidal antibiotics, ciprofloxacin and tobramycin against ASST were increased by more than 4-fold at the high inoculum level of 9 log CFU/mL. This would provide practical information for better understanding the clinical efficacy of the currently used antibiotics by considering the antibiotic stability during incubation time at different inoculum levels.

Antimicrobial Activity of N-Halamine–Coated Materials in Broiler Chicken Houses

2018 ◽  
Vol 81 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Tian Ren ◽  
Mingyu Qiao ◽  
Lei Zhang ◽  
Jean Weese ◽  
Tung-Shi Huang ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Typhimurium ◽  
Broiler Chicken ◽  
Treated Wood ◽  
Antimicrobial Activities ◽  
Complete Inactivation ◽  
Coated Materials ◽  
Metal Aluminum ◽  
Broiler House

ABSTRACT The antimicrobial activity of 1-chloro-2,2,5,5-tetramethyl-4-imidazoidinone (MC), a nonbleaching N-halamine compound, was investigated on materials commonly used in broiler production, including stainless steel, galvanized metal, aluminum, plastic, and pressure-treated wood. MC aqueous solutions at 0.02, 0.04, and 0.06% were challenged with Salmonella Typhimurium and Campylobacter jejuni at 6 log CFU/mL, resulting in complete inactivation of both bacteria in 30 min with 0.06% MC. Follow-up experiments were performed using test materials treated with 0.1 and 1% MC and challenged with Salmonella Typhimurium and C. jejuni at 6 log CFU per coupon. Stability of MC on the various surfaces of testing materials was assessed, and the chlorine content of the materials was measured using iodometric thiosulfate titration over a 4-week period. Antimicrobial activities were evaluated by a sandwich test on each sampling day during 4 weeks of storage. On the samples treated with 1% MC, bacteria at 6 log CFU per coupon were completely inactivated within 2 h of contact time. The antimicrobial activity extended to 4 weeks, and the active chlorine atoms in the treated materials decreased from the initial 1016 to 1015 atoms per cm2. Overall, MC had high stability and long-lasting antimicrobial activity, which suggests that MC has high potential for use as a novel antimicrobial agent to lower the microbial load on broiler house materials.

scholarly journals Antimicrobial Activities of Hydrophobically Modified Poly(Acrylate) Films and Their Complexes with Different Chain Length Cationic Surfactants

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 244
Author(s):  
Ioana Cătălina Gîfu ◽  
Monica Elisabeta Maxim ◽  
Ludmila Otilia Cinteza ◽  
Marcela Popa ◽  
Ludmila Aricov ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Cationic Surfactants ◽  
Antimicrobial Properties ◽  
Multilayer Films ◽  
Antimicrobial Activities ◽  
Layer By Layer ◽  
Antimicrobial Efficiency ◽  
Hydrophobically Modified ◽  
Multilayered Systems ◽  
The Stability

Multilayer films from hydrophobically modified poly(acrylic acid) (HMPA) and their complexes with cationic surfactants were successfully prepared using the layer-by-layer (LbL) method. Alkyl trimethylammonium bromide derivatives with various lengths of the hydrophobic chain (C10–C18) were used to interact with the HMPA polymer, generating highly hydrophobic domains in the films and contributing to the antimicrobial properties of the prepared coating. The antimicrobial efficiency against common pathogens such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans was investigated in relationship with the morphology and composition of the thin films. The wettability and roughness of the multilayered systems were evaluated using atomic force microscopy (AFM) and contact angle measurements. The effects of the microbial exposure on the surface properties of the prepared films were investigated in order to assess the stability of the HMPA-deposited multilayers and the durability of the antimicrobial activity. The hydrophobically modified films exhibited antimicrobial activity against the studied pathogens. The best efficiency was registered in the case of S. aureus, which showed an inhibition of growth up to 100% after 2 h. C. albicans proved to be less sensitive to the effect of the multilayers deposited from HMPA–surfactant complexes. These results suggest that HMPA and HMPA–surfactant complex LbL multilayer films can be used as promising materials in antimicrobial surface coatings with increased resistance to pathogens during exposure.

Antimicrobial activity of actinomycetes associated with an unidentified sponge from lemukutan island, Indonesia on various medium and incubation time

2012 ◽  
Vol 1 (10) ◽  
pp. 98
Author(s):  
Risa Nofiani* ◽  
Mega Sari Juane ◽  
Dr. Safiana ◽  
Puji Ardiningsih ◽  
Afghani Jayuska ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Incubation Time ◽  
Antimicrobial Activities ◽  
Determinative Bacteriology ◽  
Preliminary Screening ◽  
Antimicrobial Assay

Three isolates of Actinomycetes namely MA02, MA03, and MA04 were isolated from an unidentified sponge, Lemukutan Island, Indonesia. They were identified as Streptomyces based on Bergey’s Manual of Determinative Bacteriology. In the preliminary screening, all of the isolates showed antimicrobial activities towards 13 microorganism tests. However, the activities were not similar when their extract produced from various medium and incubation time  were tested. Their cultivation was conducted on M13 agar with incubation time for 3 days, M13 broth with incubation time for 4 days, M2+ broth with incubation time for 7 days and M2+ broth with incubation time for 9 days. The result of antimicrobial assay showed difference in the ability to inhibit the microorganism tests. The  best antimicrobial activity of the extracts based on cultivated condition (medium and incubation time)  for Streptomyces MA02, Streptomyces MA03, and Streptomyces MA04 were M2+ broth for 3 days, M2+ broth for 9 days and M2+ broth for 9 days respectively.

scholarly journals Antimicrobial Activity of Nanoemulsion in Combination with Cetylpyridinium Chloride in Multidrug-Resistant Acinetobacter baumannii

2013 ◽  
Vol 57 (8) ◽  
pp. 3568-3575 ◽  
Author(s):  
Yoon Y. Hwang ◽  
Karthikeyan Ramalingam ◽  
Diane R. Bienek ◽  
Valerie Lee ◽  
Tao You ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Acinetobacter Baumannii ◽  
Cetylpyridinium Chloride ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antibiofilm Activity ◽  
Antibiotic Resistant ◽  
Content Type ◽  
A Cell ◽  
Triton X

ABSTRACTAcinetobacter baumanniihas emerged as a serious problematic pathogen due to the ever-increasing presence of antibiotic resistance, demonstrating a need for novel, broad-spectrum antimicrobial therapeutic options. Antimicrobial nanoemulsions are emulsified mixtures of detergent, oil, and water (droplet size, 100 to 800 nm) which have broad antimicrobial activity against bacteria, enveloped viruses, and fungi. Here, we screened the antimicrobial activities of five nanoemulsion preparations against fourAcinetobacter baumanniiisolates to identify the most suitable preparation for further evaluation. Among them, N5, which contains 10% (vol/vol) Triton X-100, 25% (vol/vol) soybean oil, and 1% (wt/vol) cetylpyridinium chloride (CPC), showed the best efficacy againstA. baumanniiin both its planktonic and biofilm forms and was selected for further study. Our data demonstrate that, while the killing of planktonic forms ofA. baumanniiwas due to the 1% CPC component of our nanoemulsions, the breakdown of biofilms was achieved via the emulsified oil and detergent fractions. Furthermore, we documented the effect of ethanol and NaCl in combination with N5 on planktonicA. baumannii. In killing curves of N5 combined with other agents (ethanol or NaCl), a synergistic effect of a ≥2-log decrease in CFU/ml was observed. The antibiofilm activity of N5 was confirmed via a cell proliferation test and scanning electron microscopy. The effects of exposure to severe environmental conditions, which simulates the field conditions in Iraq and Afghanistan, were evaluated, and this exposure did not affect the overall antimicrobial activity of N5. These studies lay a solid foundation for the utilization of nanoemulsions against the antibiotic-resistant forms ofA. baumannii.

scholarly journals Efficacy and Mechanism of Traditional Medicinal Plants and Bioactive Compounds against Clinically Important Pathogens

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 257 ◽  
Author(s):  
Mickymaray
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plants ◽  
Bioactive Compounds ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Pharmacological Agents ◽  
Antibiotic Resistant ◽  
Diverse Range ◽  
Traditional Medicinal Plants ◽  
Wide Range

Traditional medicinal plants have been cultivated to treat various human illnesses and avert numerous infectious diseases. They display an extensive range of beneficial pharmacological and health effects for humans. These plants generally synthesize a diverse range of bioactive compounds which have been established to be potent antimicrobial agents against a wide range of pathogenic organisms. Various research studies have demonstrated the antimicrobial activity of traditional plants scientifically or experimentally measured with reports on pathogenic microorganisms resistant to antimicrobials. The antimicrobial activity of medicinal plants or their bioactive compounds arising from several functional activities may be capable of inhibiting virulence factors as well as targeting microbial cells. Some bioactive compounds derived from traditional plants manifest the ability to reverse antibiotic resistance and improve synergetic action with current antibiotic agents. Therefore, the advancement of bioactive-based pharmacological agents can be an auspicious method for treating antibiotic-resistant infections. This review considers the functional and molecular roles of medicinal plants and their bioactive compounds, focusing typically on their antimicrobial activities against clinically important pathogens.

scholarly journals In Vitro Evaluation of Antimicrobial Activity and Cytotoxicity of Different Nanobiotics Targeting Multidrug Resistant and Biofilm Forming Staphylococci

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mennatallah A. Mohamed ◽  
Maha Nasr ◽  
Walid F. Elkhatib ◽  
Wafaa N. Eltayeb
Keyword(s):  
Antimicrobial Activity ◽  
Rat Hepatocytes ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antibiotic Resistant ◽  
Diphenyltetrazolium Bromide ◽  
New Antibiotics ◽  
Conventional Antibiotics

Antibiotic-resistant and biofilm-forming bacteria have surprisingly increased over recent years. On the contrary, the rate of development of new antibiotics to treat these emerging superbugs is very slow. Therefore, the aim of this study was to prepare novel nanobiotic formulations to improve the antimicrobial activity of three antibiotics (linezolid, doxycycline, and clindamycin) against Staphylococci. Antibiotics were formulated as nanoemulsions and evaluated for their antimicrobial activities and cytotoxicities. Cytotoxicity of the conventional antibiotics and nanobiotics was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on rat hepatocytes. Half-maximal inhibitory concentration (IC50) was estimated from an experimentally derived dose-response curve for each concentration using GraphPad Prism software. Upon quantitative assessment of Staphylococcus biofilm formation, eighty-four isolates (66.14 %) were biofilm forming. Linezolid and doxycycline nanobiotics exhibited promising antibacterial activities. On the contrary, clindamycin nanobiotic exhibited poor antibacterial activity. Minimum biofilm inhibitory concentrations showed that 73.68 %, 45.6%, and 5.2% of isolates were sensitive to linezolid, doxycycline, and clindamycin nanobiotics, respectively. Results of this study revealed that antibiotics loaded in nanosystems had a higher antimicrobial activity and lower cytotoxicities as compared to those of conventional free antibiotics, indicating their potential therapeutic values.

scholarly journals In VitroAntimicrobial Activity of Ethanolic Extract of Polish Propolis against Biofilm FormingStaphylococcus epidermidisStrains

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Robert D. Wojtyczka ◽  
Małgorzata Kępa ◽  
Danuta Idzik ◽  
Robert Kubina ◽  
Agata Kabała-Dzik ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Bacterial Growth ◽  
Incubation Time ◽  
Biofilm Formation ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
Antimicrobial Activities ◽  
Growth Reduction ◽  
Degree Of Reduction

The aim of the presented study was to examine the antimicrobial activity of ethanol extract of Polish propolis (EEPP) against biofilm-forming CoNS strainsin vitro. Our results revealed that EEPP displayed varying degrees of activity against CoNS with MIC values ranging from 1.56 to 0.78 mg/mL. The average MIC was 1.13 ± 0.39 mg/mL while calculated MIC50and MIC90values were 0.78 mg/mL and 1.56 mg/mL, respectively. The biofilm formation ability by all testedS. epidermidisstrains was inhibited at EEPP concentrations ranging from 0.39 to 1.56 mg/mL. The degree of reduction of AlamarBlue was directly associated with the proliferation ofS. epidermidisstrains. The increased proliferation ofS. epidermidisstrains was observed after 12 and 24 hours of incubation in the presence of EEPP concentrations ranging from 0.025 to 0.39 mg/mL. These results suggest that antimicrobial activities of EEPP againstS. epidermidisexpressed as the reduction of bacterial growth, reduction of biofilm formation ability, and the intensity of proliferation were significantly affected by incubation time and EEPP concentration used as well as the interactions between these factors.

Plant-Derived Compounds Inactivate Antibiotic-Resistant Campylobacter jejuni Strains

2008 ◽  
Vol 71 (6) ◽  
pp. 1145-1149 ◽  
Author(s):  
SADHANA RAVISHANKAR ◽  
LIBIN ZHU ◽  
BIBIANA LAW ◽  
LYNN JOENS ◽  
MENDEL FRIEDMAN
Keyword(s):  
Antimicrobial Activity ◽  
Food Safety ◽  
Campylobacter Jejuni ◽  
Incubation Time ◽  
Bacterial Populations ◽  
Antibiotic Resistant ◽  
Microbial Survival ◽  
Incubation Periods ◽  
Resistant Strains ◽  
Phosphate Buffered Saline

Sixty-three Campylobacter jejuni isolates were screened for their resistance to the antibiotics ampicillin, cefaclor, ciprofloxacin, erythromycin, gentamycin, tetracycline, and trimethoprim-sulfamethoxazole. Based on this screen, the resistant strains D28a and H2a and the nonresistant strain A24a were selected for evaluation of their resistance and susceptibility to inactivation by cinnamaldehyde and carvacrol, the main constituents of plant-derived cinnamon and oregano oils, respectively. Different concentrations (0.05, 0.1, and 0.2% [vol/vol] in sterile phosphate-buffered saline) of cinnamaldehyde and carvacrol were added to C. jejuni cultures with initial populations of 104 CFU/ml. The samples were then mixed thoroughly and incubated at 37°C. Viable bacterial populations were enumerated at incubation periods of 0, 30, 60, and 120 min. The results indicate that the extent of inhibition of microbial survival was related to both the nature and concentration of antimicrobials and the incubation time. Both cinnamaldehyde and carvacrol exhibited rapid antimicrobial activity against both antibiotic-resistant and non-resistant C. jejuni strains, at concentrations of ~0.1% and higher. The antimicrobial efficacy of cinnamaldehyde was greater than that of carvacrol. The possible significance of the results for microbiological food safety is discussed.

scholarly journals Broad spectrum antimicrobial activities from spore-forming bacteria isolated from the Vietnam Sea

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10117
Author(s):  
Khanh Minh Chau ◽  
Dong Van Quyen ◽  
Joshua M. Fraser ◽  
Andrew T. Smith ◽  
Thi Thu Hao Van ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Pathogens ◽  
Paenibacillus Polymyxa ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Antibiotic Resistant ◽  
Future Drug ◽  
Spore Forming Bacteria

The widespread occurrence of pathogenic bacteria resistant to last-line antibiotics has resulted in significant challenges in human and veterinary medicine. There is an urgent need for new antimicrobial agents that can be used to control these life threating pathogens. We report the identification of antimicrobial activities, against a broad range of bacterial pathogens, from a collection of marine-derived spore-forming bacteria. Although marine environments have been previously investigated as sources of novel antibiotics, studies on such environments are still limited and there remain opportunities for further discoveries and this study has used resources derived from an under-exploited region, the Vietnam Sea. Antimicrobial activity was assessed against a panel of Gram-positive and Gram-negative bacteria, including several multi-drug resistant pathogens. From a total of 489 isolates, 16.4% had antimicrobial activity. Of 23 shortlisted isolates with the greatest antimicrobial activity, 22 were Bacillus spp. isolates and one was a Paenibacillus polymyxa isolate. Most of the antimicrobial compounds were sensitive to proteases, indicating that they were proteins rather than secondary metabolites. The study demonstrated that marine bacteria derived from the Vietnam Sea represent a rich resource, producing antimicrobial compounds with activity against a broad range of clinically relevant bacterial pathogens, including important antibiotic resistant pathogens. Several isolates were identified that have particularly broad range activities and produce antimicrobial compounds that may have value for future drug development.

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