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Scientific Reports Mar 2023Essential oils are highly concentrated natural extracts obtained from plants, rich in bioactive constituents with antimicrobial properties, but the distinctive climate...
Essential oils are highly concentrated natural extracts obtained from plants, rich in bioactive constituents with antimicrobial properties, but the distinctive climate of the Western Himalayan region influences the same. Aromatic and medicinal plants, viz., Origanum majorana, Origanum vulgare, Cymbopogon winterianus, Pelargonium graveolens, and Nepeta cataria were grown in the foothills of the Western Himalayan condition and evaluated for essential oil content, composition, and their effect on some of the most common pathogenic microorganisms. The essential oil content (%) was 0.77, 0.45, 1.37, 0.15 and 0.17% in O. majorana, O. vulgare, C. winterianus, P. graveolens, and N. cataria, respectively. The major essential oil constituents of the isolated oils were terpinen-4-ol, thymol, citronellal, citronellol, and nepetalactone, contributing 41.24%, 31.81%, 43.13%, 43.35% and 91.43% in O. majorana, O. vulgare, C. winterianus, P. graveolens, and N. cataria, respectively. Well-diffusion assay revealed that the essential oil of O. majorana and O. vulgare was active against both the tested Gram-positive, viz., Bacillus subtilis MTCC 121, Micrococcus luteus MTCC 2470, and Staphylococcus aureus MTCC 96; and Gram-negative, viz., Escherichia coli MTCC 43, Klebsiella pneumoniae MTCC 109, and Pseudomonas aeruginosa MTCC 2453 bacteria, while the essential oil of C. winterianus, P. graveolens, and N. cataria showed activity against only some Gram-positive bacteria. Minimum inhibitory concentration (v/v) values indicated the highest efficacy of O. majorana essential oil against B. subtilis (0.5%), M. luteus (1%), and S. aureus (1%), while O. vulgare was most efficient to E. coli (2%) and K. pneumoniae (2%). C. winterianus essential oil did not inhibit any bacterial strains. M. luteus was susceptible to the essential oil of P. graveolens (1%) and N. cataria (0.5%) at low concentrations. Present findings showed the association between the chemical constituents' profile of isolated essential oils from the Himalayan region and their antimicrobial activity, indicating their perspective to be utilized as antibacterial means.
Topics: Oils, Volatile; Escherichia coli; Staphylococcus aureus; Anti-Infective Agents; Anti-Bacterial Agents; Lamiaceae; Origanum; Microbial Sensitivity Tests
PubMed: 36966174
DOI: 10.1038/s41598-023-31875-3 -
Frontiers in Microbiology 2021Salmonellosis is a foodborne infection caused by Domestic poultry species are one of the main reservoirs of , which causes the foodborne infection salmonellosis, and...
Salmonellosis is a foodborne infection caused by Domestic poultry species are one of the main reservoirs of , which causes the foodborne infection salmonellosis, and are responsible for many cases of animal-to-human transmission. Keeping backyard chickens is now a growing trend, increasing the frequency of direct contact with the flock and, by consequence, the incidence of infections. KATMIRA1933 and B-1895 are probiotic bacilli that produce the bacteriocins subtilosin A and subtilin, respectively. The antimicrobial activity of the two strains was determined against the reference strain ATCC 10420. The cell-free supernatant of KATMIRA1933 inhibited biofilm formation by subsp. serovar Hadar, subsp. serovar Enteritidis phage type 4, and subsp. serovar Thompson by 51.1, 48.3, and 56.9%, respectively. The cell-free supernatant of B-1895 inhibited the biofilm formation of these strains by 30.4, 28.6, and 35.5%, respectively. These findings suggest that the bacillus strains may have the potential to be used as probiotics and antibiotic alternatives for the control of in poultry. The number of planktonic cells was unaffected by treatment with the cell-free supernatant. A co-culture of the strains with either bacilli showed no signs of growth inhibition, suggesting that it might have been quorum sensing that is affected by the two strains.
PubMed: 33679639
DOI: 10.3389/fmicb.2021.615328 -
International Journal of Molecular... Oct 2022The growing industrial and medical use of gold nanoparticles (AuNPs) requires environmentally friendly methods for their production using microbial biosynthesis. The...
The growing industrial and medical use of gold nanoparticles (AuNPs) requires environmentally friendly methods for their production using microbial biosynthesis. The ability of actinobacteria of the genus to synthesize AuNPs in the presence of chloroauric acid (HAuCl) was studied. The effect of elevated (0.8-3.2 mM) concentrations of HAuCl on bacterial viability, morphology, and intracellular accumulation of AuNPs by different species was shown. An increase in surface roughness, a shift of the zeta potential to the positive region, and the formation of cell aggregates of IEGM 766 and IEGM 1135 during nanoparticle synthesis were revealed as bacterial adaptations to toxic effects of HAuCl. The possibility to biosynthesize AuNPs at a five times higher concentration of chloroauric acid compared to chemical synthesis, for example, using the citrate method, suggests greater efficiency of the biological process using species. The main parameters of biosynthesized AuNPs (size, shape, surface roughness, and surface charge) were characterized using atomic force microscopy, dynamic and electrophoretic light scattering, and also scanning electron microscopy in combination with energy-dispersive spectrometry. Synthesized by spherical AuNPs have smaller (30-120 nm) dimensions and are positively (12 mV) charged, unlike AuNPs isolated from cells (40-200 nm and -22 mV, respectively). Such differences in AuNPs size and surface charge are due to different biomolecules, which originated from cells and served as capping agents for nanoparticles. Biosynthesized AuNPs showed antimicrobial activity against Gram-positive () and Gram-negative () bacteria. Due to the positive charge and high dispersion, the synthesized by . AuNPs are promising for biomedicine, whereas the AuNPs formed by . IEGM 1135 are prone to aggregation and can be used for biotechnological enrichment of gold-bearing ores.
Topics: Gold; Metal Nanoparticles; Rhodococcus; Actinobacteria; Anti-Bacterial Agents; Escherichia coli
PubMed: 36361740
DOI: 10.3390/ijms232112939 -
Turkish Journal of Pharmaceutical... Dec 2022Benth. (OS) is a commonly used medicinal plant for curbing bacterial infections globally. This work aimed to fabricate poloxamer and chitosan-based gels loaded with...
OBJECTIVES
Benth. (OS) is a commonly used medicinal plant for curbing bacterial infections globally. This work aimed to fabricate poloxamer and chitosan-based gels loaded with standardized aqueous-ethanolic OS leaf extracts and investigate their antimicrobial efficacy as a potential remedy against ocular infections.
MATERIALS AND METHODS
gels containing 0.5% w/v OS extract prepared using cold dispersion method were subjected to physicochemical characterization, including -release studies. Antimicrobial efficacy was tested against , and using agar diffusion method.
RESULTS
Thin layer chromatography and high performance liquid chromatography chromatograms confirmed the presence of rosmarinic acid (RA) and sinensitin in OS extracts with same retention factor (0.26 and 0.49) and retention times (12.2 and 20.7 min) against reference standards. A homogenous brown coloured gel exhibited low viscosity as a solution and increased viscosity in gel form at ocular temperature. The optimized formulations, P7 (21% P407/4% P188), P8 (21% P407/5% P188) and F5 (1.5% chitosan and 45% -glycerophosphate) exhibited ideal ocular pH (7.27-7.46), phase transition at ocular temperature (33-37°C) and prolonged RA release up to 12 h. Formulation F5 showed an inhibition zone of 4.3 mm against .
CONCLUSION
Among all, formulation F5 alone exhibited modest antimicrobial activity against . OS extracts at 5% and 10% were most active against tested bacteria however, loading them into gels resulted in sedimentation. Hence, isolation of RA from OS extract is suggested before loading into formulations for a better antimicrobial activity.
PubMed: 36544377
DOI: 10.4274/tjps.galenos.2021.40121 -
Heliyon Oct 2021is an important vector for many pathogens. Previous studies have revealed a role for midgut bacteria during pathogen infection in mosquitoes; however, studies of...
is an important vector for many pathogens. Previous studies have revealed a role for midgut bacteria during pathogen infection in mosquitoes; however, studies of midgut bacteria are limited. We examined the diversity of midgut bacteria in female laboratory-colonized and field-collected . A total of 31 bacterial genera were identified representing 10 and 28 genera of laboratory-colonized and field-collected , respectively. The predominant bacterial genera in the laboratory-colonized were and , whereas the bacterial diversity in the field-collected exhibited a higher proportion of and as the dominant genera. However, only showed a significant difference between laboratory-colonized and field-collected . The midgut bacterial species were identified from 30 laboratory-colonized mosquitoes. A total of 16 bacterial species were identified and the predominant bacterial species was , followed by and Field mosquitoes were collected from the Sing Buri, Chumphon, and Yala Provinces of Thailand. The midgut bacterial species identified from the 10 collected from the Sing Buri Province included and was the only bacteria identified from this area. Midgut bacterial species were identified from 40 filed-collected from Chumphon Province. A total of 25 bacterial species were identified and the predominant species were and Only 15 bacterial species were identified from the mosquitoes collected from Chumphon Province. A total of 18 bacterial species were identified from 30 collected from Yala Province and the predominant species were and Only 12 bacterial species were found in mosquitoes collected from Yala Province. These findings indicate changes in the midgut bacteria population in from various locales, which may result from variability in the blood-meal source, diet, or habitat. A comprehensive survey of the midgut bacteria community prevalence in wild populations is critical for not only gaining a better understanding of the role of this bacterium in shaping the microbial community in but also for informing current and future mosquito and disease control programs.
PubMed: 34765765
DOI: 10.1016/j.heliyon.2021.e08259 -
Microorganisms Sep 2023Aerosols in caves are natural tracers and, together with climatic parameters, provide a detailed insight into atmospheric conditions, responses to climatic changes and...
Aerosols in caves are natural tracers and, together with climatic parameters, provide a detailed insight into atmospheric conditions, responses to climatic changes and anthropogenic influences in caves. Microbiological air monitoring in show caves is becoming increasingly useful to understand changes in cave ecosystems and to implement and review measures for sustainable cave use and tourism development. In 2017 and 2018, air along tourist trails in caves Postojnska jama and Škocjanske jame (Slovenia) was sampled before and after tourist visits. Samples were analysed using culture-dependent methods, flow cytometry, detection of β-D-glucan and lipopolysaccharide and compared with CO and temperature data to measure anthropogenic influences and seasonality on aerobiota. While the presence of tourists significantly increased concentrations of airborne microorganisms ( < 0.05), β-D-glucan and CO did not show such a trend and were more dependent on seasonal changes. Locally, concentrations of cultivable microorganisms above 1000 CFU/m were detected, which could have negative effects on the autochthonous microbiota and possibly on human health. A mixture of bacteria typically associated with humans was found in the air and identified with MALDI-TOF MS. Using MALDI-TOF MS, we achieved a 69.6% success rate in identification. , , and spp. were recognized as good indicators of cave anthropisation.
PubMed: 37894039
DOI: 10.3390/microorganisms11102381 -
Molecules (Basel, Switzerland) Jan 2023Benzoxazole alkaloids exhibit a diverse array of structures and interesting biological activities. Herein we report the identification of a benzoxazole alkaloid-encoding...
Benzoxazole alkaloids exhibit a diverse array of structures and interesting biological activities. Herein we report the identification of a benzoxazole alkaloid-encoding biosynthetic gene cluster ( BGC) in the marine-derived actinomycete sp. SCSIO 07395 and the heterologous expression of this BGC in . This approach led to the discovery of five new benzoxazole alkaloids microechmycin A-E (-), and a previously synthesized compound . Their structures were elucidated by HRESIMS and 1D and 2D NMR data. Microechmycin A (1) showed moderate antibacterial activity against SCSIO ML01 with the minimal inhibitory concentration (MIC) value of 8 μg mL.
Topics: Micromonospora; Anti-Bacterial Agents; Alkaloids; Magnetic Resonance Spectroscopy; Genomics; Molecular Structure
PubMed: 36677886
DOI: 10.3390/molecules28020821 -
Marine Drugs Nov 2022A chemical investigation of a methanol extract of sp., a marine sponge collected from the Philippines, identified 12 unreported scalarane-type alkaloids-scalimides A-L...
A chemical investigation of a methanol extract of sp., a marine sponge collected from the Philippines, identified 12 unreported scalarane-type alkaloids-scalimides A-L (-)-together with two previously described scalarin derivatives. The elucidation of the structure of the scalaranes based on the interpretation of their NMR and HRMS data revealed that - featured a -alanine-substituted E-ring but differed from each other through variations in their oxidation states and substitutions occurring at C16, C24, and C25. Evaluation of the antimicrobial activity of - against several Gram-positive and Gram-negative bacteria showed that and were active against and respectively, with MIC values ranging from 4 to 16 μg/mL.
Topics: Animals; Anti-Bacterial Agents; Gram-Negative Bacteria; Porifera; Bacillus subtilis; Methanol
PubMed: 36422004
DOI: 10.3390/md20110726 -
Veterinary Medicine International 2020Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the...
INTRODUCTION
Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the disinfectants.
AIM
The current study investigated the prevalence of streptococci/micrococci in poultry farms of Bangladesh and the efficacy of commercial disinfectants (Savlon, Lysol, Quatovet, Virkon S, and Virocid) along with alcohol against these pathogens to adopt appropriate strategies.
MATERIALS AND METHODS
Conventional approaches and the 16S rRNA gene sequencing were performed to confirm the isolates at the species level along with microtiter biofilm assay to determine their biofilm-forming ability. Efficacy of the disinfectants was tested against those isolates using agar well diffusion and minimum inhibitory concentration (MIC) test by broth dilution method using different dilutions of the disinfectants.
RESULTS
( = 32), ( = 7), and ( = 4) were confirmed among 102 presumptively screened streptococci/micrococci isolates from 43 samples. No single disinfectant showed equally high efficacy against all three bacterial species in agar well diffusion test, although Virocid showed the lowest MIC against all three of them. Lysol was least effective among the commercial disinfectants by both MIC and diffusion method, although each commercial disinfectant was more effective than alcohol. Considering both the average diameter of the inhibition zones and the MIC values, efficacy can be interpreted as Virocid > Quatovet > Savlon > Virkon S > Lysol. Although the efficacy decreased with decreasing concentration, the disinfectants retained a satisfactory level of efficacy at 50% concentration. Among test pathogens, was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 and 1/5 were strong biofilm producers, which may cause more reduction in the efficacy in environmental conditions.
CONCLUSION
As no ideal disinfectant was found in the study, the efficacy of the disinfectants should be routinely evaluated and validated to ensure the sanitation standards in the poultry sector.
PubMed: 33062244
DOI: 10.1155/2020/8811540 -
Microbiology Resource Announcements Jun 2020We report the draft genome sequences of two strains, MFP06 and MFP07, isolated from human skin. The genome assemblies consist of 2,480 and 2,417 kbp with 2,337 and...
We report the draft genome sequences of two strains, MFP06 and MFP07, isolated from human skin. The genome assemblies consist of 2,480 and 2,417 kbp with 2,337 and 2,240 coding sequences, respectively. The genomes contain genes potentially involved in osmotic stress tolerance, DNA repair, monoacylglycerol hydrolysis, and beta-lactone synthesis.
PubMed: 32554793
DOI: 10.1128/MRA.00545-20