scholarly journals Detection of Food Spoilage and Pathogenic Bacteria Based on Ligation Detection Reaction Coupled to Flow-Through Hybridization on Membranes

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
K. Böhme ◽  
P. Cremonesi ◽  
M. Severgnini ◽  
Tomás G. Villa ◽  
I. C. Fernández-No ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Cost Effective ◽  
Rrna Gene ◽  
Bacterial Identification ◽  
Dot Blot ◽  
Culture Collections ◽  
Ligation Detection Reaction ◽  
Flow Through ◽  
Food Safety And Quality

Traditional culturing methods are still commonly applied for bacterial identification in the food control sector, despite being time and labor intensive. Microarray technologies represent an interesting alternative. However, they require higher costs and technical expertise, making them still inappropriate for microbial routine analysis. The present study describes the development of an efficient method for bacterial identification based on flow-through reverse dot-blot (FT-RDB) hybridization on membranes, coupled to the high specific ligation detection reaction (LDR). First, the methodology was optimized by testing different types of ligase enzymes, labeling, and membranes. Furthermore, specific oligonucleotide probes were designed based on the 16S rRNA gene, using the bioinformatic tool Oligonucleotide Retrieving for Molecular Applications (ORMA). Four probes were selected and synthesized, being specific forAeromonasspp.,Pseudomonasspp.,Shewanellaspp., andMorganella morganii, respectively. For the validation of the probes, 16 reference strains from type culture collections were tested by LDR and FT-RDB hybridization using universal arrays spotted onto membranes. In conclusion, the described methodology could be applied for the rapid, accurate, and cost-effective identification of bacterial species, exhibiting special relevance in food safety and quality.

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.

A Microbiology Teaching Lab: Using Koch's Postulates to Determine the Cause of “Peep Pox” in Marshmallow Peeps

2018 ◽  
Vol 80 (9) ◽  
pp. 676-679
Author(s):  
John L. Dahl ◽  
Wayne Gatlin
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Cost Effective ◽  
Time Constraints ◽  
Limited Time ◽  
Koch’S Postulates ◽  
Ethical Concerns ◽  
Effective Time ◽  
Microbial Isolation ◽  
Koch's Postulates

Koch's postulates are regularly included in the lecture portion of microbiology courses, but rarely are they demonstrated in a microbiology teaching lab. This is understandable given the logistical challenges of undergraduates working with pathogenic bacteria, ethical concerns using animals, and limited time constraints of a weekly lab period. Here we present a cost-effective, time-friendly lab activity that demonstrates the principles of microbial isolation and infection assays that are part of fulfilling Koch's postulates. The disease is “peep pox” caused by a gelatinase-positive bacterial species hydrolyzing marshmallow peeps that proxy as infected animals.

scholarly journals COMPARATIVE ANALYSIS OF METAL NANOPARTICLES SYNTHESIZED FROM HIBISCUS ROSA SINESIS AND THEIR ANTIBACTERIAL ACTIVITY ESTIMATION AGAINST NINE PATHOGENIC BACTERIA

2017 ◽  
Vol 10 (5) ◽  
pp. 323
Author(s):  
Shruti Tyagi
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Au Nanoparticles ◽  
Size Range ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Cost Effective ◽  
Antibacterial Activities ◽  
Agar Disc ◽  
Vis Spectroscopy

Objective: This study demonstates  a simple, cost effective protocol  for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities  of AgNPs  and AuNPs were evaluated against  9 pathogenic bacterial species  Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs  were obtained in 13.01 to 28.14 nm size range, while AuNPs were in  6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates  that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities  of AgNPs,  the zone of inhibition significantly increased with the  increases of concentrations of AgNPs in all pathogenic bacterial species  except  in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity  was displayed  only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial  agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold  nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.  

scholarly journals A First Insight into the Structural and Functional Comparison of Environmental Microbiota in Freshwater Turtle Chinemys reevesii at Different Growth Stages under Pond and Greenhouse Cultivation

2020 ◽  
Vol 8 (9) ◽  
pp. 1277 ◽  
Author(s):  
Aiguo Zhou ◽  
Shaolin Xie ◽  
Di Sun ◽  
Pan Zhang ◽  
Han Dong ◽  
...  
Keyword(s):  
Water Quality ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Freshwater Turtle ◽  
Growth Stages ◽  
Rrna Gene ◽  
Important Indicator ◽  
Adult Growth ◽  
Greenhouse Cultivation ◽  
Different Growth Stages

The microbial community structure of water is an important indicator for evaluating the water quality of the aquaculture environment. In this study, the investigation and comparison of the bacterial communities of pond cultivation (PC) and greenhouse cultivation (GC) between hatchling, juvenile, and adult growth stages of C. reevesii were performed. In addition, the V4 regions of the 16S rRNA gene were sequenced. The Chao1 richness estimator of the PC group was significantly higher than that of the GC group. The beta diversity showed that the microbiotas of the two groups were isolated from each other. The dominant phyla were Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes, Verrucomicrobia, and Planctomycetes in the PC group and Proteobacteria, Bacteroidetes, Firmicutes, Cyanobacteria, Chloroflexi, and Actinobacteria in the GC group. Both the numbers and the types of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations differed between the PC and GC groups. The prediction of bacterial phenotype implied that the GC environment is more likely to deteriorate, and turtles are more susceptible to pathogens than those of the PC environment. In addition, a total of nine potential pathogenic bacteria were identified and the correlation of environmental factors analyses showed significant differences of bacterial species between the PC and GC groups, while the potential pathogenic bacteria showed significant correlation with the stocking density, temperature, pH, orthophosphate (PO4-P), and dissolved oxygen (DO) in both the PC and GC groups. Noticeably, this is the first report to describe the different microbiota characteristics of the different cultivation environments in the different growth stages of C. reevesii, which will provide valuable data for water quality adjustment, disease prevention, and the healthy breeding of turtles.

scholarly journals Development of a Universal Microarray Based on the Ligation Detection Reaction and 16S rRNA Gene Polymorphism To Target Diversity of Cyanobacteria

2004 ◽  
Vol 70 (12) ◽  
pp. 7161-7172 ◽  
Author(s):  
Bianca Castiglioni ◽  
Ermanno Rizzi ◽  
Andrea Frosini ◽  
Kaarina Sivonen ◽  
Pirjo Rajaniemi ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Environmental Samples ◽  
Rrna Gene ◽  
Accurate Identification ◽  
Culture Collections ◽  
Reliable Identification ◽  
Ligation Detection Reaction ◽  
Universal Array ◽  
Axenic Strains

ABSTRACT The cyanobacteria are photosynthetic prokaryotes of significant ecological and biotechnological interest, since they strongly contribute to primary production and are a rich source of bioactive compounds. In eutrophic fresh and brackish waters, their mass occurrences (water blooms) are often toxic and constitute a high potential risk for human health. Therefore, rapid and reliable identification of cyanobacterial species in complex environmental samples is important. Here we describe the development and validation of a microarray for the identification of cyanobacteria in aquatic environments. Our approach is based on the use of a ligation detection reaction coupled to a universal array. Probes were designed for detecting 19 cyanobacterial groups including Anabaena/Aphanizomenon, Calothrix, Cylindrospermopsis, Cylindrospermum, Gloeothece, halotolerants, Leptolyngbya, Palau Lyngbya, Microcystis, Nodularia, Nostoc, Planktothrix, Antarctic Phormidium, Prochlorococcus, Spirulina, Synechococcus, Synechocystis, Trichodesmium, and Woronichinia. These groups were identified based on an alignment of over 300 cyanobacterial 16S rRNA sequences. For validation of the microarrays, 95 samples (24 axenic strains from culture collections, 27 isolated strains, and 44 cloned fragments recovered from environmental samples) were tested. The results demonstrated a high discriminative power and sensitivity to 1 fmol of the PCR-amplified 16S rRNA gene. Accurate identification of target strains was also achieved with unbalanced mixes of PCR amplicons from different cyanobacteria and an environmental sample. Our universal array method shows great potential for rapid and reliable identification of cyanobacteria. It can be easily adapted to future development and could thus be applied both in research and environmental monitoring.

262 Reproductive Microbiomes as Predicators of Fertility in Beef Cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 135-136
Author(s):  
Rebecca K Poole
Keyword(s):  
Beef Cattle ◽  
Pathogenic Bacteria ◽  
Reproductive Tract ◽  
Bacterial Species ◽  
Uterine Disease ◽  
Rrna Gene ◽  
Vaginal Microbiome ◽  
Sequencing Studies ◽  
Culture Independent ◽  
Genus Lactobacillus

Abstract Over the past decade, a multitude of research has sought to understand the complexity and role of the reproductive microbiome as it pertains to fertility. Previously, the reproductive microbiome was evaluated using culture-dependent methods; however, recent advancements in culture-independent, 16S rRNA gene amplicon community sequencing have vastly expanded our understanding of the reproductive tract microbiome. Early sequencing studies sought to compare the vaginal microbiome of cattle to the vaginal microbiome of healthy women, which predominantly consists of bacteria in the genus Lactobacillus and believed to be an indicator of fertility. In the vagina of beef cattle, however, there are incredibly low abundances of Lactobacillus and a greater diversity of bacterial species present. Beta-diversity, which examine differences in bacterial communities between samples, does not appear to differ in the vagina between unbred, open, or pregnant cattle. In postpartum beef cattle just prior to breeding, there are greater levels of diversity and increased bacterial species richness in the vagina compared to the uterus. Research on bacterial species within the uterus have primarily focused on pathogenic bacteria in postpartum cattle diagnosed with uterine disease. Fewer studies have investigated uterine bacterial species in presumed healthy postpartum beef cattle and the subsequent effects on fertility outcomes (e.g., pregnant vs. open at day 30). When evaluating the uterine microbiome during an industry standard estrus synchronization protocol, bacterial community abundance and diversity reduce over time regardless of resulting fertility outcomes. The greatest difference in uterine bacterial abundance between resulting pregnant and non-pregnant cattle appears to occur just prior to breeding. Numerous mechanisms could be contributing to the fluctuations in the uterine microbiome in beef cattle including circulating hormone concentrations or local immunoregulation. This presentation will focus on recent research investigating potential mechanisms that may alter the reproductive microbiome and ultimately impact fertility.

scholarly journals Study on Air Bacteria at Different Altitudinal Locations in Tezpur to Tawang Axis

2020 ◽  
Vol 5 (2) ◽  
pp. 93-102
Author(s):  
Soumya Chatterjee ◽  
Sibnarayan Datta ◽  
Leeza Banu ◽  
Mohan G. Vairale ◽  
Sonika Sharma
Keyword(s):  
16S Rrna ◽  
Human Health ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Bacterial Load ◽  
Well Being ◽  
Molecular Techniques ◽  
Rrna Gene ◽  
Public Health Perspective ◽  
Pathogenic Potential

Microflora plays an important role in modulating environmental quality. Among microflora, bacteria are omnipresent in the environment. Pathogenic bacteria, present in air, are known to affect significantly the health and well-being of human, animal or plant populations. Air bacteria monitoring is thus essential for surveillance of pathogenic microorganisms from public health perspective besides its significant implications in detection and mitigation of biothreat related issues. Despite the geo-politically strategic importance of northeast India, there is scarcity of data on human health and disease surveillance. Considering these facts, we, for the first time studied the bacterial diversity of air at six important sites adjacent to the international border in the northeast region of India, having an altitude range of 73 m (Tezpur) to 4170 m (Sela Pass) above sea level. Standard microbiological techniques, such as Tryptone Soya Agar, Mannitol salt and McConkey agar strips and plates were used for air bacterial load assessment and culture for subsequent analysis using biochemical and molecular techniques. Following RFLP study, twenty six different bacterial colonies were isolated. Subsequently, bacteria identification was carried out by examining the substrate utilisation patterns, sequencing 16S rRNA gene and phylogenetic analysis. Results of the study reveal that the isolates mostly belong to two genera Bacillus and Staphylococcus (eleven in each genus), along with Micrococcus, Pseduomonas and Acinetobacter. Based on significant match of our sequences with that of medically important bacterial 16S rRNA sequences available at 16SpathDB 2.0 and review of available literature, we found that a number of these bacterial species have the pathogenic potential. In this manuscript we report our results and discuss the importance of air bacterial surveillance from the perspective of human health, hygiene and biothreat mitigation.

scholarly journals P673 Microbial diversity in newly diagnosed treatment naïve Inflammatory Bowel Disease patients

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S594-S595
Author(s):  
S Ellul ◽  
P Rausch ◽  
A Pisani ◽  
C Bang ◽  
P Ellul ◽  
...  
Keyword(s):  
Species Richness ◽  
Beta Diversity ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Alpha Diversity ◽  
Rrna Gene ◽  
Healthy Controls ◽  
Newly Diagnosed ◽  
Treatment Naïve ◽  
Stool Samples

Abstract Background The role of microbiome with the alteration between commensal and pathogenic bacteria, has been linked to IBD. Meanwhile Escherichia coli Nissle 1917, Lactobacillus rhamnosus GG (LGG) and faecal transplantation are used in IBD. The aim of this study was to prospectively determine faecal microbiota composition of newly diagnosed treatment naïve IBD patients. Methods Patients diagnosed with IBD between January 2018-September 2019 were recruited. Clinical data was collected and patients asked to submit stool samples for microbiome analysis. Stool samples from a control population were recruited and analysed via the bacterial 16s rRNA gene sequencing on illumine MiSeq. Results 100 IBD patients (CD: n=46, UC: n=53 & IBDU: n=1) and 97 controls with specific inclusion and exclusion criteria collected. IBD patients were noted to display reduced average species richness and community evenness compared to healthy controls (Alpha- Diversity) (Figure 1). Beta-diversity between microbial communities of healthy individuals and IBD patients was significantly different, but no observed separation between the two types of IBD was noted (Figure 2). 11 ASVs were abundant in CD patients including: ASV-70 – Lactobacillus gasseri, Klebsiella uncl., Candidatus-saccharibacteria, ASV-157 - Acteroides clarus and ASV 249- Parasutterella uncl. In UC cohort, 10 ASVs were abundant including: ASV 6-Escherichia/Shigella uncl., ASB-41-Sutterella wadsworthensis, ASV 44- Bacteroides faecis and Actinobacteria. An association between UC and ASV 313 (Faecalibacteria) was present. In the microbiome of healthy controls, 20 ASVs were abundant, including: ASV-14 G-Alistipes uncl., ASV 20-(Akkermansia muciniphila),(bacterium belonging to the phylum Verrucomicrobia), ASV 321 (Clostridia uncl.), ASV 96 (Rumminococcaceae uncl.), Alistepes uncl. (ASV 61), Subdoligranulum uncl. (ASV 453) and the unclassifiable bacteria. A higher amount of Verrucomicrobia was present in the healthy group as opposed to the IBD. Conclusion ASV 249- Parasutterella unlc., was indicative of CD associated microbiome through the indicator species analysis. Typical microbiome changes in IBD patients include increased abundance of the pro-inflammatory species with a reduction in anti-inflammatory bacterial species, with a noticeable reduction in alpha and beta diversity. In the local cohort, a particular change in the local α- and β diversity was noted to be present between healthy controls and IBD cohort. This could be a potential way in which targeted therapeutic approaches using specific dosage and durations of probiotic or faecal transplant can be used to alter faecal microbiome using specific bacteria present in healthy controls and with elimination of potentially harmful bacteria in IBD patients. Figure 1: Alpha diversity between different Groups using Chao1 species richness and Simpson 1-D Figure 2: Beta diversity between different groups using Bray-Curtis dissimilarity, Jaccard distance.

scholarly journals Identification of bacteria by poly-aromatic hydrocarbons biosensors

2021 ◽  
Author(s):  
Yaniv Shlosberg ◽  
Yair Farber ◽  
Salah Hasson ◽  
Valery Bulatov ◽  
Israel Schechter
Keyword(s):  
Pathogenic Bacteria ◽  
Polyaromatic Hydrocarbons ◽  
Bacterial Species ◽  
Environmental Water ◽  
Intensity Increase ◽  
Bacterial Identification ◽  
Industrial Facilities ◽  
Degrading Bacteria ◽  
Identification Of Bacteria ◽  
Poly Aromatic Hydrocarbons

Human health is consistently threatened by different species of pathogenic bacteria. To fight the spread of diseases, it is important to develop rapid methods for bacterial identification. Over the years, different kinds of biosensors were developed for this cause. Another environmental risk are polyaromatic hydrocarbons (PAHs) that may be emitted from industrial facilities and pollute environmental water and soil. One of the methods for their purification is conducted by the addition of bacteria that can degrade the PAHs, while the bacteria itself can be filtrated at the end of the process. Although many studies reported monitoring of the PAHs degradation by fluorescence, not much attention was dedicated to studying the influence of the PAHs on the intrinsic fluorescence of the degrading bacteria. In this work, we apply synchronous fluorescence (SF) measurements to study the ability of the 5 PAHs: 9Antracene carboxylic acid (9ACA), Pyrene, Perylene, Pentacene, and Chrysene to interact with bacteria and change its fluorescence spectra. We show that upon incubation of each PAH with the bacterium E.coli only the 2 PAHs 9ACA and Perylene cause an intensity decrease in the emission at λ = 300 – 375 nm, which derives from the emission of Tyrosine and Tryptophane (TT). Also, we show that upon incubation of 9ACA and Perylene with 5 different pathogenic bacteria, the intensity increase or decrease in the TT emission is unique to each bacterial species. Based on this observation, we suggest that the PAHs 9ACA and Perylene can be utilized as biosensors for bacterial identification.

scholarly journals Molecular Characterization of Bacteria, Detection of Enterotoxin Genes, and Screening of Antibiotic Susceptibility Patterns in Traditionally Processed Meat Products of Sikkim, India

2021 ◽  
Vol 11 ◽  
Author(s):  
Meera Ongmu Bhutia ◽  
Namrata Thapa ◽  
Jyoti Prakash Tamang
Keyword(s):  
Antibiotic Susceptibility ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Meat Products ◽  
Resistance Pattern ◽  
Enzyme Linked Immunosorbent Assay ◽  
Processed Meat ◽  
Rrna Gene ◽  
Antibiotic Susceptibility Patterns ◽  
Susceptibility Patterns

The lesser-known traditionally processed meat products such as beef kargyong, pork kargyong, satchu, and khyopeh are popular food items in the Himalayan state of Sikkim in India. The present study aimed to assess the microbiological safety of traditional meat products by identifying the potential spoilage or pathogenic bacteria, detecting the enterotoxins, and screening the antibiotic susceptibility patterns. The pH and moisture contents of the meat products varied from 5.3 to 5.9 and from 1.5 to 18%, respectively. The microbial loads of aerobic bacteria were 105 to 107 cfu/g, Staphylococcus 103 to 106 cfu/g, Bacillus 104 to 106 cfu/g, and total coliform 102 to 107 cfu/g, respectively. Based on 16S rRNA gene sequencing, the bacterial species isolated from traditionally processed meat products were Staphylococcus piscifermentans, Citrobacter freundii, Enterococcus faecalis, Salmonella enterica, Staphylococcus aureus, Citrobacter werkmanii, Klebsiella pneumoniae, Macrococcus caseolyticus, Klebsiella aerogenes, Staphylococcus saprophyticus, Pseudocitrobacter anthropi, Citrobacter europaeus, Shigella sonnei, Escherichia fergusonii, Klebsiella grimontii, Burkholderia cepacia, and Bacillus cereus. The enzyme-linked immunosorbent assay (ELISA) tests detected Salmonella spp. and enterotoxins produced by B. cereus well as Staphylococcus in a few tested samples. However, the PCR method did not detect the virulence genes of B. cereus and Salmonella in the isolates. Virulence gene (sea) was detected in S. piscifermentans BSLST44 and S. piscifermentans BULST54 isolated from beef kargyong and in S. aureus PSST53 isolated from pork kargyong. No enterotoxins were detected in khyopeh samples. The antibiotic sensitivity test showed that all bacterial strains were susceptible toward gentamicin, cotrimoxazole, norfloxacin, and trimethoprim. Gram-positive bacteria showed 100% sensitivity against clindamycin and erythromycin; however, 50% of the resistance pattern was observed against oxacillin followed by penicillin (33%) and ampicillin (27%).

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