scholarly journals Exploring clinically isolated Staphylococcus sp. bacteriocins revealed the production of amonabactin, micrococcin, and α-circulocin

2021 ◽  
Author(s):  
Mohamed Ali Kassem ◽  
Amal Eissa Saafan ◽  
Faten Bayomy ◽  
Ahmed Osama El-Gendy
Keyword(s):  
Micrococcus Luteus ◽  
16S Rrna Gene Sequencing ◽  
Inhibitory Effect ◽  
Indicator Bacteria ◽  
Proteinase K ◽  
Diffusion Method ◽  
Partial Purification ◽  
Rrna Gene ◽  
Ionization Mass ◽  
Bacteriocin Genes

Background and Objectives: Bacteriocins are considered alternative non-conventional antimicrobials produced by certain bacteria with activity against closely related species. The present study focuses on screening, characterization, and partial purification of bacteriocins produced by Staphylococcus sp. isolated from different clinical sources such as pus and blood. Materials and Methods: A total of 100 Staphylococcus isolates were screened for bacteriocin production using spot on lawn assay and agar diffusion method against five indicator bacteria. Bacteriocins from five selected highly active isolates were subjected to proteinase-K enzyme, different pH, and heating at different temperatures, and investigated the stabilities of their antimicrobials. Two selected isolates, MK65 and MK88, were molecularly identified by 16S rRNA gene sequencing, explored for the presence of 18 bacteriocin genes, and liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS) was used to identify their different metabolites. Results: Twenty isolates exhibited inhibitory effect against at least one indicator bacteria. Micrococcus luteus ATCC 4698 showed the highest sensitivity to such bacteriocins. Proteinase K, acidic pH, and heating at 100°C triggered marked activity inhibition. However, amylase enzyme, alkaline pH, and heating at 80°C caused trivial effects. Four out of eighteen bacteriocin genes were detected using PCR. Fermentation, partial purification, and LC-HRESIMS of total protein extracts of two selected isolates, MK65 and MK88, revealed the production of different antimicrobial peptides. Conclusion: To the best of our knowledge, this is the first study to report the production of micrococcin and α-circulocin from Staphylococcus aureus MK65 and the production of amonabactin from Staphylococcus epidermidis MK88.

scholarly journals Evaluation of Commercial Disinfectants against Staphylococcus lentus and Micrococcus spp. of Poultry Origin

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Otun Saha ◽  
Nadira Naznin Rakhi ◽  
Arif Istiaq ◽  
Israt Islam ◽  
Munawar Sultana ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Bacterial Species ◽  
16S Rrna Gene Sequencing ◽  
Average Diameter ◽  
Diffusion Method ◽  
Dilution Method ◽  
Rrna Gene ◽  
Poultry Farms ◽  
Rrna Gene Sequencing ◽  
Selection Of

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. Staphylococcus lentus (n = 32), Micrococcus luteus (n = 7), and Micrococcus aloeverae (n = 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, M. aloeverae was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 S. lentus and 1/5 M. luteus 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.

scholarly journals Surface Microflora of Four Smear-Ripened Cheeses

2005 ◽  
Vol 71 (11) ◽  
pp. 6489-6500 ◽  
Author(s):  
Jérôme Mounier ◽  
Roberto Gelsomino ◽  
Stefanie Goerges ◽  
Marc Vancanneyt ◽  
Katrien Vandemeulebroecke ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Debaryomyces Hansenii ◽  
Rflp Analysis ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Staphylococcus Equorum ◽  
Dna Restriction ◽  
Rrna Gene Sequencing ◽  
Mtdna Rflp

ABSTRACT The microbial composition of smear-ripened cheeses is not very clear. A total of 194 bacterial isolates and 187 yeast isolates from the surfaces of four Irish farmhouse smear-ripened cheeses were identified at the midpoint of ripening using pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR, and 16S rRNA gene sequencing for identifying and typing the bacteria and Fourier transform infrared spectroscopy and mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) analysis for identifying and typing the yeast. The yeast microflora was very uniform, and Debaryomyces hansenii was the dominant species in the four cheeses. Yarrowia lipolytica was also isolated in low numbers from one cheese. The bacteria were highly diverse, and 14 different species, Corynebacterium casei, Corynebacterium variabile, Arthrobacter arilaitensis, Arthrobacter sp., Microbacterium gubbeenense, Agrococcus sp. nov., Brevibacterium linens, Staphylococcus epidermidis, Staphylococcus equorum, Staphylococcus saprophyticus, Micrococcus luteus, Halomonas venusta, Vibrio sp., and Bacillus sp., were identified on the four cheeses. Each cheese had a more or less unique microflora with four to nine species on its surface. However, two bacteria, C. casei and A. arilaitensis, were found on each cheese. Diversity at the strain level was also observed, based on the different PFGE patterns and mtDNA RFLP profiles of the dominant bacterial and yeast species. None of the ripening cultures deliberately inoculated onto the surface were reisolated from the cheeses. This study confirms the importance of the adventitious, resident microflora in the ripening of smear cheeses.

Selection of Bacillus thuringiensis against Pathogenic Nematodes Attacking Pepper Tree

2020 ◽  
Vol 36 (3) ◽  
pp. 57-62
Author(s):  
Minh Vo Van ◽  
Tuan Vo Chau ◽  
My Pham Тhi ◽  
Ha Do Thu ◽  
Trang Le Vu Khanh
Keyword(s):  
Bacillus Thuringiensis ◽  
16S Rrna Gene Sequencing ◽  
Inhibitory Effect ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Nematode Eggs ◽  
Science And Education ◽  
Pepper Tree ◽  
Rrna Gene Sequencing ◽  
Meloidogyne Sp

Nine strains belonging to the Bacillus genus have been isolated from soil samples in Tien Phuoc district, Quang Nam province. They were capable of surviving at 42°C, and the Bl, B4, B7 and B9 strains could produce toxic crystals at this temperature. B7 had the most promising characteristics in terms of spore-forming ability. The result of the 16S rRNA gene sequencing showed that B7 belongs to the Bacillus thuringiensis species, which is known to effectively control root-knot Meloidogyne sp. nematodes attacking pepper tree. This study was aimed at evaluating the inhibitory effect of the bacterial isolate under study on root-knot eggs and juveniles. It was shown that the highest inhibitory activity of the cultures of the bacterial strains under study was observed at their concentration of 109cells/mL; in this case, up to 89.67% of nematode eggs and 100% of juveniles J2 were killed after 10 h of treatment. Bacillus thuringiensis, Meloidogyne sp., pepper tree, root-knot, nematodes We are grateful to the Danang University of Science and Education and Duy Tan University for supporting this study.

Influence of Trichoderma spp on Macrophoma theicola branch canker disease in South Indian tea gardens, India

2021 ◽  
pp. 1-7
Author(s):  
Jeyaraman Mareeswaran
Keyword(s):  
Trichoderma Viride ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Trichoderma Spp ◽  
Canker Disease ◽  
Isolation And Characterization ◽  
South Indian ◽  
Indian Tea ◽  
Branch Canker

Abstract Branch canker disease caused by the fungus Macrophoma theicola is a major stem disease that reduces the yield of south Indian tea plantations. Hence the present study aimed to assess the efficacy of the biocontrol agent Trichoderma spp against various isolates of Macrophoma spp. For this matter, different tea-growing regions of south India were surveyed for the isolation and characterization of Macrophoma spp. Then, fungal biocontrol strains (Trichoderma viride, Trichoderma atroviride, Trichoderma harzianum, and Gliocladium virens) were procured from microbial type culture collection Centre (MTCC) to screen their antagonistic potential on different isolates Macrophoma spp. The spores of Macrophoma spp were examined through a light microscope and identified by their peculiar morphological features such as non-septum pycnidiospores present in the sac and oval shape spore with stalk and confirmed using 18S rRNA gene sequence. The results revealed that the biocontrol G. virens followed by T. harzianum showed a higher inhibitory effect on different isolates of Macrophoma spp in the dual plate and culture filtrate studies. In the well diffusion method, the fungal biocontrol agents were found to be exhibit non-significant differences on different isolates of branch canker pathogen. The hyphal interactions studies showed that the pathogenic hyphal wall shrunk and penetrated by the interaction of G. virens.

scholarly journals Detection of methicillin resistant staphylococcus aureus using mec a, ribotyping and antibiogram profile of Pakistani clinical isolates

2019 ◽  
Vol 26 (06) ◽  
Author(s):  
Adeela Fatima ◽  
Imran Sajid ◽  
Saba Riaz ◽  
Muhammad Saeed
Keyword(s):  
Antibiotic Sensitivity ◽  
16S Rrna Gene Sequencing ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Research Centre ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Cross Sectional ◽  
Sensitivity Pattern ◽  
Rrna Gene Sequencing

Background: The objective of this study was to determine the incidence of MRSA with their antibiotic susceptibility pattern and molecular characterization of these strains. Study Design: Cross sectional study. Setting: Microbiology section of Citilab and Research Centre, Lahore. Period: March 2014 to June 2016. Materials and Methods: Bacterial isolates were retrieved from different specimens of pus/wound, blood and other body fluids. These were characterized using conventional (catalase, DNase, coagulase etc), phenotypic and molecular techniques (oxacillin and cefoxitin susceptibility, 16S rRNA gene sequencing and mec-A gene) methods of identification. Antibiotic sensitivity pattern was also detected by applying standard Kirby Bauer disc diffusion method. Results: Out of all the isolated strains, the frequency of MSSA (methicillin sensitive Staphylococcu saureus) was more than the MRSA and it was found that the male patients were more affected than the female patients. All of the isolates were resistant to cefoxitin and oxacillin while most of them showed positive band of mec-A gene. All of the MRSA isolates showed resistant to penicillin followed by azithromycin, erythromycin, co-trimoxazole and ciprofloxacin, while these strains were sensitive to linezolid and vancomycin, followed by teicoplanin, fosfomycin and fusidic acid. Conclusion: In conclusion, proper diagnosis of MRSA required conventional, phenotypic molecular techniques in our hospital diagnostic settings. This will help in choosing the effective antibiotics combat the infection.

scholarly journals Compost bacteria as potential agents in biological plant control

2021 ◽  
Vol 61 (4) ◽  
pp. 319-326
Keyword(s):  
Pathogenic Fungi ◽  
16S Rrna Gene Sequencing ◽  
Alcaligenes Faecalis ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Fungistatic Activity ◽  
Activity Spectrum ◽  
Rrna Gene Sequencing

The assumptions of integrated pest management put great emphasis on the development of non-chemical methods which increases the interest in biological methods and the search for microorganisms that would be an alternative to the most frequently used fungicides. The aim of the experiments was the isolation of the compost bacteria, in vitro determination of their fungistatic activity against some pathogenic fungi of the genus Fusarium, Alternaria, Sclerotinia, Botrytis, Rhizoctonia and Pythium and identification of selected isolates. From the backyard compost, 44 bacterial strains were isolated and assessed for the fungistatic properties by the well diffusion method. The obtained results allowed for the selection of 12 isolates of compost bacteria, characterised by the broadest and the strongest fungistatic activity spectrum against tested fungi. Identification of bacterial isolates by: MALDI-TOF mass spectrometry and 16S rRNA gene sequencing methods showed their belonging to the species Bacillus subtilis, Alcaligenes faecalis, Stenotrophomonas maltophilia and Serratia liquefaciens.

scholarly journals Coaggregation between Aquatic Bacteria Is Mediated by Specific-Growth-Phase-Dependent Lectin-Saccharide Interactions

2000 ◽  
Vol 66 (1) ◽  
pp. 431-434 ◽  
Author(s):  
Alex H. Rickard ◽  
Stephen A. Leach ◽  
Clive M. Buswell ◽  
Nicola J. High ◽  
Pauline S. Handley
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Growth Phase ◽  
Specific Growth ◽  
Micrococcus Luteus ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Aquatic Bacteria ◽  
Rrna Gene Sequencing

ABSTRACT Coaggregating strains of aquatic bacteria were identified by partial 16S rRNA gene sequencing. The coaggregation abilities of four strains of Blastomonas natatoria and one strain ofMicrococcus luteus varied with culture age but were always maximum in the stationary phase of growth. Each member of a coaggregating pair carried either a heat- and protease-sensitive protein (lectin) adhesin or a saccharide receptor, as coaggregation was reversed by sugars.

scholarly journals Identification of Homologous Polyprenols from Thermophilic Bacteria

2021 ◽  
Vol 9 (6) ◽  
pp. 1168
Author(s):  
Lucia Gharwalová ◽  
Andrea Palyzová ◽  
Helena Marešová ◽  
Irena Kolouchová ◽  
Lucie Kyselová ◽  
...  
Keyword(s):  
High Performance ◽  
Hot Springs ◽  
Thermophilic Bacteria ◽  
Limit Of Detection ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Ionization Mass ◽  
Rp Hplc ◽  
Rrna Gene Sequencing ◽  
Undecaprenyl Phosphate

Sixteen strains of five genera of thermophilic bacteria, i.e., Alicyclobacillus, Brevibacillus, Geobacillus, Meiothermus, and Thermus, were cultivated at a temperature from 42 to 70 °C. Twelve strains were obtained from the Czech Collection of Microorganisms, while four were directly isolated and identified by 16S rRNA gene sequencing from the hot springs of the world-famous Carlsbad spa (Czech Republic). Polyprenol homologs from C40 to C65 as well as free undecaprenol (C55), undecaprenyl phosphate, and undecaprenyl diphosphate were identified by shotgun analysis and RP-HPLC/MS-ESI+ (reverse phase high-performance liquid chromatography–high-resolution positive electrospray ionization mass spectrometry). The limit of detection (50 pM) was determined for individual homologs and free polyprenols and their phosphates. Thus, it has been shown that at least some thermophilic bacteria produce not just the major C55 polyprenol as previously described, but a mixture of homologs.

scholarly journals Isolation, Characterization, and Molecular Identification of Indigenous Bacteria from Fermented Almonds (Prunus dulcis)

2020 ◽  
pp. 15-22
Author(s):  
Salwa Nurhasanah ◽  
Edy Fachrial ◽  
Nyoman Ehrich Lister
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Licheniformis ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Diffusion Method ◽  
Subtilis Strain ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Disk Diffusion Method ◽  
Indigenous Bacteria

Aims: This study aims to isolate and identify the indigenous bacteria of almonds fermentation. Methods: Characterization of the indigeneous bacteria are using gram staining, biochemical tests, 16SrRNA gene sequencing, and the antimicrobial activity against Escherichia coli bacteria. Results: Approximately 28 x 106 CFU / mL bacteria were obtained from almonds fermentations with 14 isolates from enrichment results. Three randomly selected isolates were gram-positive rod-shaped with a negative catalase and positive fermentation test. However, one isolate showed positive results on the motility test. The antimicrobial test results from the three randomly selected isolates using the disk diffusion method obtained inhibition zones of 7 mm, 6.7 mm, and 7 mm, respectively. Therefore, by using 16S rRNA gene sequencing, three different microorganisms were found, namely Bacillus subtilis strain IAM 12118, Bacillus Piscis strain 16MFT21, and Bacillus licheniformis strain BaDB27. Conclusion: It was found that Bacillus subtilis strain IAM 12118, Bacillus Piscis strain 16MFT21, and Bacillus licheniformis strain BaDB27 in almonds fermentation and also can be used as probiotic bacteria.

scholarly journals Biosynthesis and Characterization of Silver Nanoparticles produced by Phormidium ambiguum and Desertifilum tharense

2021 ◽  
Author(s):  
Amira Lotfy Hanna ◽  
Hayam Hamouda ◽  
Hanan Goda ◽  
Tarek Elsayed ◽  
Mahmoud Sadik
Keyword(s):  
Silver Nanoparticles ◽  
Micrococcus Luteus ◽  
16S Rrna Gene Sequencing ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Face Centered Cubic ◽  
Ag Nps ◽  
Rrna Gene Sequencing

Abstract The world faces a challenge with pervasion of multidrug resistant bacteria which encouraged the scientists to develop and discover alternative ecofriendly and easy to produce new antibacterial agents. Two Egyptian cyanobacteria were isolated and identified according to 16S rRNA gene sequencing as Phormidium ambiguum and Desertifilum tharense . The sequences were deposited in the GenBank with accession numbers of MW762709 and MW762710 for Desertifilum tharense and Phormidium ambiguum, respectively. These isolates have the ability to produce silver nanoparticles (Ag-NPs) extra- and intracellularly under light and dark conditions. The results of UV-Vis analysis showed promising extracellular Ag-NPs synthesis by Desertifilum tharense and Phormidium ambiguum under light conditions. Therefore, these Ag-NPs were characterized and evaluated for antibacterial and antioxidant activity. TEM, SEM and XRD analyses revealed the spherical crystals with face-centered cubic structures and size range of 6.24–11.4 nm and 6.46–12.2 nm for Ag-NPs of Desertifilum tharense and Phormidium ambiguum , respectively. XRD and EDX results clearly confirmed the successful synthesis of Ag-NPs in its oxide form or chloride form. The FTIR spectrum data confirmed the presence of hydroxyl and amide groups. Desertifilum tharense Ag-NPs displayed the largest inhibition zone ranged from 9 mm against Micrococcus luteus ATCC 10240 to 25 mm against methicillin resistant S. aureus (MRSA) ATCC 43300. For Phormidium ambiguum Ag-NPs, the inhibition zone diameter was in a range of 9–18 mm. The Ag-NPs of Phormidium ambiguum exhibited the highest scavenging activity of 48.7% comparing with that of Desertifilum tharense which displayed 43.753%.

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