Differentiated ovine tracheal epithelial cells support the colonisation of pathogenic and non-pathogenic strains of Mannheimia haemolytica

Abstract Mannheimia haemolytica is the primary bacterial species associated with respiratory disease of ruminants. A lack of cost-effective, reproducible models for the study of M. haemolytica pathogenesis has hampered efforts to better understand the molecular interactions governing disease progression. We employed a highly optimised ovine tracheal epithelial cell model to assess the colonisation of various pathogenic and non-pathogenic M. haemolytica isolates of bovine and ovine origin. Comparison of single representative pathogenic and non-pathogenic ovine isolates over ten time-points by enumeration of tissue-associated bacteria, histology, immunofluorescence microscopy and scanning electron microscopy revealed temporal differences in adhesion, proliferation, bacterial cell physiology and host cell responses. Comparison of eight isolates of bovine and ovine origin at three key time-points (2 h, 48 h and 72 h), revealed that colonisation was not strictly pathogen or serotype specific, with isolates of serotype A1, A2, A6 and A12 being capable of colonising the cell layer regardless of host species or disease status of the host. A trend towards increased proliferative capacity by pathogenic ovine isolates was observed. These results indicate that the host-specific nature of M. haemolytica infection may result at least partially from the colonisation-related processes of adhesion, invasion and proliferation at the epithelial interface.

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Construction of a telomerase-immortalized porcine tracheal epithelial cell model for swine-origin mycoplasma infection

10.21203/rs.3.rs-61553/v1 ◽

2020 ◽

Author(s):

Xing Xie ◽

Fei Hao ◽

Haiyan Wang ◽

Maoda Pang ◽

Yuan Gan ◽

...

Keyword(s):

Cell Model ◽

Telomerase Activity ◽

Respiratory Pathogens ◽

Human Telomerase Reverse Transcriptase ◽

Tracheal Epithelial Cells ◽

A Cell ◽

Tracheal Epithelial ◽

Human Telomerase ◽

Porcine Respiratory ◽

Infection Study

Abstract Background: Primary porcine tracheal epithelial cells (PTECs) are an appropriate model for studying the molecular mechanism of various porcine respiratory diseases, including swine-origin mycoplasmas, which were isolated from pig respiratory tract and were mainly found on the mucosal surface surrounding swine trachea. However, the short proliferation ability of primary PTECs greatly limits their lifespan.Results: In this study, we carefully isolated and cultured primary PTECs. Besides, we constructed immortalized PTECs by transfecting primary PTECs with the recombinant constructed plasmid pEGFP-hTERT containing human telomerase reverse transcriptase (hTERT). Immortal PTECs (hTERT-PTECs) maintained both the morphological and functional characteristics of primary PTECs, as indicated by the expression of cytokeratin 18, cell-cycle analysis, proliferation assay, western blotting, telomerase activity assay, karyotype analysis and quantitative RT-PCR. hTERT-PTECs had an extended replicative lifespan, higher telomerase activity, and enhanced proliferative activity. In addition, using this cell line, the lack of transformed and grown tumors in nude mice indicated that it could be safely applied in further studies. Moreover, hTERT-PTECs were vulnerable to all swine-origin mycoplasmas and were suitable as a cell adhesion model.Conclusions: In summary, hTERT-PTECs could be widely used as an adhesion cell model for swine-origin mycoplasmas and in the infection study of various porcine respiratory pathogens.

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

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200730144536 ◽

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.

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Endothelin stimulates chloride secretion across canine tracheal epithelium

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1991.261.2.l188 ◽

1991 ◽

Vol 261 (2) ◽

pp. L188-L194 ◽

Cited By ~ 2

Author(s):

P. I. Plews ◽

Z. A. Abdel-Malek ◽

C. A. Doupnik ◽

G. D. Leikauf

Keyword(s):

Epithelial Cells ◽

Short Circuit ◽

Second Messengers ◽

Short Circuit Current ◽

Chloride Secretion ◽

Tracheal Epithelium ◽

Membrane Phospholipids ◽

Cl Secretion ◽

Tracheal Epithelial Cells ◽

Tracheal Epithelial

The endothelins (ET) are a group of isopeptides produced by a number of cells, including canine tracheal epithelial cells. Because these compounds are endogenous peptides that may activate eicosanoid metabolism, we investigated the effects of ET on Cl secretion in canine tracheal epithelium. Endothelin 1 (ET-1) was found to produce a dose-dependent change in short-circuit current (Isc) that increased slowly and reached a maximal value within 10-15 min. When isopeptides of ET were compared, 300 nM ET-1 and ET-2 produced comparable maximal increases in Isc, whereas ET-3 produced smaller changes in Isc (half-maximal concentrations of 2.2, 7.2, and 10.4 nM, respectively). Ionic substitution of Cl with nontransported anions, iodide and gluconate, reduced ET-1-induced changes in Isc. Furthermore, the response was inhibited by the NaCl cotransport inhibitor, furosemide. In paired tissues, ET-1 significantly increased mucosal net 36Cl flux without significant effect on 22Na flux. The increase in Isc induced by ET was diminished by pretreatment with indomethacin. The second messengers mediating the increase in Isc were investigated in cultured canine tracheal epithelial cells. ET-1 stimulated the release of [3H]arachidonate from membrane phospholipids, increased intracellular Ca2+ (occasionally producing oscillations), and increased adenosine 3',5'-cyclic monophosphate accumulation. The latter was diminished by indomethacin. Thus ET is a potent agonist of Cl secretion (with the isopeptides having the following potency: ET-1 greater than or equal to ET-2 greater than ET-3) and acts, in part, through a cyclooxygenase-dependent mechanism.

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Selection of carcinogen-altered rat tracheal epithelial cells preexposed to 7,12-dimethylbenz[a]anthracene by their loss of a need for pyruvate to survive in culture

Carcinogenesis ◽

10.1093/carcin/5.6.789 ◽

1984 ◽

Vol 5 (6) ◽

pp. 789-796 ◽

Cited By ~ 11

Author(s):

Ann C. Marchok ◽

Shilling F. Huang ◽

Donald H. Martin

Keyword(s):

Epithelial Cells ◽

Tracheal Epithelial Cells ◽

Tracheal Epithelial ◽

Selection Of

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Arachidonic acid metabolism by canine tracheal epithelial cells. Product formation and relationship to chloride secretion.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)67169-8 ◽

1986 ◽

Vol 261 (27) ◽

pp. 12841-12849 ◽

Cited By ~ 4

Author(s):

T E Eling ◽

R M Danilowicz ◽

D C Henke ◽

K Sivarajah ◽

J R Yankaskas ◽

...

Keyword(s):

Arachidonic Acid ◽

Epithelial Cells ◽

Acid Metabolism ◽

Chloride Secretion ◽

Product Formation ◽

Arachidonic Acid Metabolism ◽

Tracheal Epithelial Cells ◽

Tracheal Epithelial

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Fucoxanthin Ameliorates Oxidative Stress and Airway Inflammation in Tracheal Epithelial Cells and Asthmatic Mice

Cells ◽

10.3390/cells10061311 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1311

Author(s):

Shu-Ju Wu ◽

Chian-Jiun Liou ◽

Ya-Ling Chen ◽

Shu-Chen Cheng ◽

Wen-Chung Huang

Keyword(s):

Oxidative Stress ◽

Epithelial Cells ◽

Airway Inflammation ◽

Inflammatory Cytokines ◽

Inflammatory Responses ◽

Therapeutic Potential ◽

Eosinophil Infiltration ◽

Tracheal Epithelial Cells ◽

Tracheal Epithelial ◽

And Oxidative Stress

Fucoxanthin is isolated from brown algae and was previously reported to have multiple pharmacological effects, including anti-tumor and anti-obesity effects in mice. Fucoxanthin also decreases the levels of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) of asthmatic mice. The purpose of the present study was to investigate the effects of fucoxanthin on the oxidative and inflammatory responses in inflammatory human tracheal epithelial BEAS-2B cells and attenuated airway hyperresponsiveness (AHR), airway inflammation, and oxidative stress in asthmatic mice. Fucoxanthin significantly decreased monocyte cell adherence to BEAS-2B cells. In addition, fucoxanthin inhibited the production of pro-inflammatory cytokines, eotaxin, and reactive oxygen species in BEAS-2B cells. Ovalbumin (OVA)-sensitized mice were treated by intraperitoneal injections of fucoxanthin (10 mg/kg or 30 mg/kg), which significantly alleviated AHR, goblet cell hyperplasia and eosinophil infiltration in the lungs, and decreased Th2 cytokine production in the BALF. Furthermore, fucoxanthin significantly increased glutathione and superoxide dismutase levels and reduced malondialdehyde (MDA) levels in the lungs of asthmatic mice. These data demonstrate that fucoxanthin attenuates inflammation and oxidative stress in inflammatory tracheal epithelial cells and improves the pathological changes related to asthma in mice. Thus, fucoxanthin has therapeutic potential for improving asthma.

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PSVII-3 Correlations between L-lactate concentrations obtained using a handheld lactate analyser and a lactate assay colorimetric kit in beef cattle transported by road

Journal of Animal Science ◽

10.1093/jas/skaa278.535 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 296-297

Author(s):

Daniela M Meléndez ◽

Sonia Marti ◽

Luigi Faucitano ◽

Derek B Haley ◽

Timothy D Schwinghamer ◽

...

Keyword(s):

Statistical Significance ◽

Cost Effective ◽

Road Transportation ◽

Long Distance ◽

Suitable Alternative ◽

Blood Samples ◽

Handheld Device ◽

Time Points ◽

Relationship Of ◽

The Relationship

Abstract Blood metabolites are used to assess a variety of animal conditions for veterinary diagnosis and research. Concentration of metabolites in blood can be measured using a commercially-available lab-based assay or in real-time using a handheld device developed to be more time- and cost-effective than the lab-based method. Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer (Lactate Scout, EFK Diagnostics, Barleben, Germany) and a lactate assay colorimetric kit (Lactate Assay Kit, Cell Biolabs Inc., San Diego, CA). Blood samples were collected by venipuncture from 96 steers (245 ± 35.7 kg BW) prior to (L1) and after 36 h, and prior to and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in colorimetric analysis. Pearson correlations were calculated to determine the relationship between the experimental methods for the quantification of L-lactate concentrations. The strengths and levels of statistical significance of the correlation varied over the observed time points, r = -0.03, P = 0.75 (L1) to r = 0.75, P = < 0.0001 (d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, P < 0.001). Based on the experimental results, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay for measuring L-lactate in transported cattle, due to variability across sampling time points and weak correlation with the traditional enzymatic method.

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Development of a Genoserotyping Method for Salmonella Infantis Detection on the Basis of Pangenome Analysis

Microorganisms ◽

10.3390/microorganisms9010067 ◽

2020 ◽

Vol 9 (1) ◽

pp. 67

Author(s):

Seung-Min Yang ◽

Jiwon Baek ◽

Eiseul Kim ◽

Hyeon-Be Kim ◽

Seyoung Ko ◽

...

Keyword(s):

Public Health ◽

Polymerase Chain Reaction ◽

Bacterial Species ◽

Cost Effective ◽

The Other ◽

Gene Marker ◽

Diagnostic Assay ◽

Chain Reaction ◽

Polymerase Chain ◽

Substantial Economic Burden

In recent years, Salmonella Infantis has become a predominant serovariant in clinical and poultry isolates, thereby imposing a substantial economic burden on both public health and the livestock industry. With the aim of coping with the steep increase in serovar Infantis prevalence, a polymerase chain reaction (PCR)-based rapid and accurate diagnostic assay was developed in this study through pangenome profiling of 60 Salmonella serovars. A gene marker, SIN_02055, was identified, which is present in the S. Infantis genome but not in the pangenome of the other serovars. Primers specific to SIN_02055 were used to accurately detect serovar Infantis, and to successfully differentiate Infantis from the other 59 serovars in real-time PCR with a R2 of 0.999 and an efficiency of 95.76%. The developed method was applied to 54 Salmonella strains belonging to eight dominant serovars, and distinguished Infantis from the other seven serovars with an accuracy of 100%. The diagnostic primer set also did not show false positive amplification with 32 strains from eight non-Salmonella bacterial species. This cost-effective and rapid method can be considered an alternative to the classic serotyping using antisera.

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