scholarly journals Characterization of Natural Lactic Flora in a Soft Cheese “Camembert of the Tessala” Made From Thermised Milk of Local Breed Cow “Brown of the Atlas”

2020 ◽  
Vol 39 (01) ◽  
Author(s):  
A. , A. , A. Dahou ◽  
A. M.A. Bekada ◽  
M. Medjahed ◽  
H. Tahlaiti ◽  
S. N. Rechidi ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Large Degree ◽  
Taste Quality ◽  
Universal Primers ◽  
Bacterial Dna ◽  
Local Breed ◽  
Isolation And Purification ◽  
Soft Cheese ◽  
Positive Controls

Microbial communities play an important role in the maturation of cheese and determine to a large degree its taste quality. The typicality and the sensory richness of Tessala camembert diversity is preserved by this microflora. In the present study, we tried after isolation and purification to characterize genotypically lactic microflora of this cheese at the end of maturation of the transformation from thermized milk of local breed cow. The bacterial DNA from twenty-two purified lactic culture was established by an amplification of ribosomal DNA 16S by specific universal primers of prokaryotes with strains reference of each isolated bacterial species used as positive controls. The results show the characteristic of the Tessala camembert by the diversity of its original lactic flora dominated by lactococci, enterococci, lactobacilli, pediococci and leuconostocs, preserved by the initial thermization of milk used to maintain the technologically-interested dairy microbial ecosystem.

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures

2017 ◽  
Vol 45 (9) ◽  
pp. 2061-2067 ◽  
Author(s):  
Christer G. Rolf ◽  
Sai-Chuen Fu ◽  
Chelsea Hopkins ◽  
Ju Luan ◽  
Margaret Ip ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Acl Reconstruction ◽  
Bacterial Infections ◽  
Bacterial Species ◽  
Hamstring Tendon ◽  
Universal Primers ◽  
Rrna Gene ◽  
Low Grade ◽  
Bacterial Dna ◽  
Normal Tendon

Background: The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria. Hypothesis: Bacteria are present in ruptured ATs but not in healthy tendons. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients with spontaneous AT ruptures and patients undergoing anterior cruciate ligament (ACL) reconstruction were recruited for this study. During AT surgical repair, excised tendinopathic tissue was collected, and healthy tendon samples were obtained as controls from hamstring tendon grafts used in ACL reconstruction. Half of every sample was reserved for DNA extraction and the other half for histology. Polymerase chain reaction (PCR) was conducted using 16S rRNA gene universal primers, and the PCR products were sequenced for the identification of bacterial species. A histological examination was performed to compare tendinopathic changes in the case and control samples. Results: Five of 20 AT rupture samples were positive for the presence of bacterial DNA, while none of the 23 hamstring tendon samples were positive. Sterile operating and experimental conditions and tests on samples, controlling for harvesting and processing procedures, ruled out the chance of postoperative bacterial contamination. The species identified predominantly belonged to the Staphylococcus genus. AT rupture samples exhibited histopathological features characteristic of tendinopathy, and most healthy hamstring tendon samples displayed normal tendon features. There were no apparent differences in histopathology between the bacterial DNA–positive and bacterial DNA–negative AT rupture samples. Conclusion: The authors have demonstrated the presence of bacterial DNA in ruptured AT samples. It may suggest the potential involvement of bacteria in spontaneous AT ruptures.

scholarly journals Identification of a Lactococcus lactis Isolated from a Fresh Local Cheese of the Western Algerian Steppe “J’ben of Naama”

2021 ◽  
Author(s):  
A.A. Dahou ◽  
A.A. Bekada ◽  
A. Homrani
Keyword(s):  
Dna Sequencing ◽  
Mixed Culture ◽  
Lactococcus Lactis ◽  
Ribosomal Dna ◽  
Bacterial Species ◽  
Sheep Breed ◽  
Universal Primers ◽  
Bacterial Dna ◽  
Genotypic Identification ◽  
Lactic Bacteria

Background: The purpose of the study is to evaluate the diversity of lactococci, lactic bacteria, recovered from “J’ben”, a local cheese made from the milk of the Rembi sheep breed, a product of exploitation in the Algerian steppe regions of Naama.Methods: The bacterial species were isolated from samples of the recovered cheese exploitation and analyzed using genotypic methods. The isolation of bacterial DNA from purified Lactococcus cultures has been established by an amplification of ribosomal DNA 16s using the specific universal primers of prokaryotes. Result: The 16s DNA sequencing of all isolates, for genotypic identification, confirmed the predominance of Lactococcus lactis. This lactic dominance determines the quality and distinctiveness of this cheese in the region. The results obtained from acidification and proteolysis kinetics met the technological requirements and good functionality, from the strains used individually and in mixed culture to the cheese processing.

scholarly journals Two-Step PCR-Based Assay for Identification of Bacterial Etiology of Otitis Media with Effusion in Infected Lebanese Children

1998 ◽  
Vol 36 (5) ◽  
pp. 1185-1188 ◽  
Author(s):  
Ghassan M. Matar ◽  
Nada Sidani ◽  
Michel Fayad ◽  
Usamah Hadi
Keyword(s):  
Otitis Media ◽  
Otitis Media With Effusion ◽  
Bacterial Species ◽  
Cost Effective ◽  
Universal Primers ◽  
Rrna Gene ◽  
Specific Primer ◽  
Specific Primers ◽  
Bacterial Dna ◽  
Species Specific

We developed and evaluated a two-step PCR-based assay with universal primers and genus- or species-specific primers for the detection of the most prevalent bacterial etiologies of otitis media with effusion (OME) in children from Lebanese hospitals. These etiologies included Haemophilus, Streptococcus, and Moraxella (Branhamella)catarrhalis, which were detected in middle-ear effusion (MEE) samples taken from children with OME. A total of 47 MEE samples were aspirated from 36 patients during insertion of a tympanostomy tube performed particularly for OME. The duration of effusion in all patients was ≥2 months. DNA was extracted from MEE samples, and PCR was initially done with DNA extracts by using the universal primers RW01 and DG74, which flank an ∼370-bp fragment found in the 16S rRNA gene of all bacterial species. For the identification of specific bacteria, we used in three separate reaction mixtures the following genus- or species-specific primers: (i) aHaemophilus-specific probe (probe RDR125) as a primer along with DG74, (ii) a Streptococcus-specific primer (primer STR1; designed by us) along with DG74, and (iii) an M. catarrhalis-specific primer pair (primer pair MCA1-MCA2). Thirty-five MEE samples (74.5%) gave the expected 370-bp band, indicating the presence of bacterial DNA in the tested samples. Of the 35 PCR-positive samples tested, 33 (94.3%) were positive forHaemophilus, 3 (8.6%) were positive forStreptococcus, and 10 (28.6%) were positive for M. catarrhalis. Ten samples (28.6%) exhibited a mixed infection and were positive for both Haemophilus and M. catarrhalis. Culture was simultaneously performed for all 47 MEE samples. Ten of the 47 MEE samples (21.3%) exhibited bacterial growth. These 10 were PCR positive for bacterial DNA. The remaining 25 PCR-positive samples were negative by culture, thus showing about 53% discordance between PCR results and those of culture. The PCR assay proved to be more sensitive than culture, more rapid, less cumbersome, and more cost-effective than the available PCR-Southern hybridization-based assays.

scholarly journals Nanopore-Sequencing Characterization of the Gut Microbiota of Melolontha melolontha Larvae: Contribution to Protection against Entomopathogenic Nematodes?

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 396
Author(s):  
Ewa Sajnaga ◽  
Marcin Skowronek ◽  
Agnieszka Kalwasińska ◽  
Waldemar Kazimierczak ◽  
Karolina Ferenc ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Entomopathogenic Nematodes ◽  
Bacterial Species ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Nanopore Sequencing ◽  
Bacterial Phyla ◽  
Melolontha Melolontha

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.

scholarly journals Construction and Characterization of a proU-gfp Transcriptional Fusion That Measures Water Availability in a Microbial Habitat

2002 ◽  
Vol 68 (9) ◽  
pp. 4604-4612 ◽  
Author(s):  
Catherine A. Axtell ◽  
Gwyn A. Beattie
Keyword(s):  
Pseudomonas Syringae ◽  
Water Availability ◽  
Water Deprivation ◽  
Bacterial Species ◽  
Transcriptional Fusion ◽  
Bacterial Biosensor ◽  
E Coli ◽  
Quantitative Manner ◽  
Microbial Habitat

ABSTRACT We constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. This fusion between the proU promoter from Escherichia coli and the reporter gene gfp was introduced into strains of E. coli, Pantoea agglomerans, and Pseudomonas syringae. The proU-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of NaCl, Na2SO4, KCl, or polyethylene glycol (molecular weight, 8000). The fusion was induced to a detectable level by NaCl concentrations of as low as 10 mM in all three bacterial species. Water deprivation induced proU-gfp expression in both planktonic and surface-associated cells; however, it induced a higher level of expression in the surface-associated cells. Following the introduction of P. agglomerans biosensor cells onto bean leaves, the cells detected a significant decrease in water availability within only 5 min. After 30 min, the populations were exposed, on average, to a water potential equivalent to that imposed by approximately 55 mM NaCl. These results demonstrate the effectiveness of a proU-gfp-based biosensor for evaluating water availability on leaves. Furthermore, the inducibility of proU-gfp in multiple bacterial species illustrates the potential for tailoring proU-gfp-based biosensors to specific habitats.

scholarly journals Rapid Identification of Bacterial Species with Bacterial DNA Microarray in Cirrhotic Patients with Spontaneous Bacterial Peritonitis

2009 ◽  
Vol 48 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Takaaki Sugihara ◽  
Masahiko Koda ◽  
Yoshiko Maeda ◽  
Tomomitsu Matono ◽  
Takakazu Nagahara ◽  
...  
Keyword(s):  
Dna Microarray ◽  
Spontaneous Bacterial Peritonitis ◽  
Bacterial Species ◽  
Rapid Identification ◽  
Bacterial Dna ◽  
Bacterial Peritonitis ◽  
Cirrhotic Patients

scholarly journals An Overview of Metabolic Activity, Beneficial and Pathogenic Aspects of Burkholderia Spp

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 321
Author(s):  
Hazem S. Elshafie ◽  
Ippolito Camele
Keyword(s):  
Secondary Metabolites ◽  
Plant Growth ◽  
Biochemical Characterization ◽  
Bacterial Species ◽  
Promoting Effect ◽  
Important Species ◽  
Beneficial Effects ◽  
Plant Growth Promoting ◽  
Rhizosphere Competence

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.

scholarly journals Characterization of Epigallocatechin-Gallate-Grafted Chitosan Nanoparticles and Evaluation of Their Antibacterial and Antioxidant Potential

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1375
Author(s):  
María J. Moreno-Vásquez ◽  
Maribel Plascencia-Jatomea ◽  
Saúl Sánchez-Valdes ◽  
Judith C. Tanori-Córdova ◽  
Francisco J. Castillo-Yañez ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Food Packaging ◽  
Inhibitory Concentration ◽  
Antioxidant Activities ◽  
Bacterial Species ◽  
Chitosan Nanoparticles ◽  
Epigallocatechin Gallate ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

Nanoparticles based on chitosan modified with epigallocatechin gallate (EGCG) were synthetized by nanoprecipitation (EGCG-g-chitosan-P). Chitosan was modified by free-radical-induced grafting, which was verified by Fourier transform infrared (FTIR). Furthermore, the morphology, particle size, polydispersity index, and zeta potential of the nanoparticles were investigated. The grafting degree of EGCG, reactive oxygen species (ROS) production, antibacterial and antioxidant activities of EGCG-g-chitosan-P were evaluated and compared with those of pure EGCG and chitosan nanoparticles (Chitosan-P). FTIR results confirmed the modification of the chitosan with EGCG. The EGCG-g-chitosan-P showed spherical shapes and smoother surfaces than those of Chitosan-P. EGCG content of the grafted chitosan nanoparticles was 330 μg/g. Minimal inhibitory concentration (MIC) of EGCG-g-chitosan-P (15.6 μg/mL) was lower than Chitosan-P (31.2 μg/mL) and EGCG (500 μg/mL) against Pseudomonas fluorescens (p < 0.05). Additionally, EGCG-g-chitosan-P and Chitosan-P presented higher Staphylococcus aureus growth inhibition (100%) than EGCG at the lowest concentration tested. The nanoparticles produced an increase of ROS (p < 0.05) in both bacterial species assayed. Furthermore, EGCG-g-chitosan-P exhibited higher antioxidant activity than that of Chitosan-P (p < 0.05) in 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and ferric-reducing antioxidant power assays. Based on the above results, EGCG-g-chitosan-P shows the potential for food packaging and biomedical applications.

Physicochemical characterization of monazite sand and its associated bacterial species from the beaches of southeastern Brazil

2021 ◽  
Author(s):  
Marcos Tadeu D’Azeredo Orlando ◽  
Elson Silva Galvão ◽  
José Luis Passamai ◽  
Alan Bragança Zordan ◽  
Cintia Garrido Pinheiro Orlando ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Physicochemical Characterization ◽  
Southeastern Brazil

scholarly journals Discovery and Characterization of Low-Molecular Weight Inhibitors of Erwinia tracheiphila

2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Bacillus Species ◽  
Erwinia Tracheiphila ◽  
Static Activity ◽  
Low Toxicity

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.

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