Biofilm formation and cellulose expression by Bordetella avium 197N, the causative agent of bordetellosis in birds and an opportunistic respiratory pathogen in humans

ABSTRACT For most, if not all, organisms, iron (Fe) is an essential element. In response to the nutritional requirement for Fe, bacteria evolved complex systems to acquire the element from the environment. The genes encoding these systems are often coordinately regulated in response to the Fe concentration. Recent investigations revealed thatBordetella avium, a respiratory pathogen of birds, expressed a number of Fe-regulated genes (T. D. Connell, A. Dickenson, A. J. Martone, K. T. Militello, M. J. Filiatraut, M. L. Hayman, and J. Pitula, Infect. Immun. 66:3597–3605, 1998). By using manganese selection on an engineered strain of B. avium that carried an Fe-regulated alkaline phosphatase reporter gene, a mutant was obtained that was affected in expression of Fe-regulated genes. To determine if Fe-dependent regulation in B. avium was mediated by afur-like gene, a fragment of the B. aviumchromosome, corresponding to the fur locus of B. pertussis, was cloned by PCR. Sequencing revealed that the fragment from B. avium encoded a polypeptide with 92% identity to the Fur protein of B. pertussis. In vivo experiments showed that the cloned gene complemented H1780, afur mutant of Escherichia coli. Southern hybridizations and PCRs demonstrated that the manganese mutant had a deletion of 2 to 3 kbp of nucleotide sequence in the region located immediately 5′ of the fur open reading frame. A spontaneous PCR-derived mutant of the B. avium fur gene was isolated that encoded a Fur protein in which a histidine was substituted for an arginine at amino acid position 18 (R18H). Genetic analysis showed that the R18H mutant gene when cloned into a low-copy-number vector did not complement the fur mutation in H1780. However, the R18H mutant gene was able to complement the fur mutation when cloned into a high-copy-number vector. The cloned wild-typefur gene will be useful as a genetic tool to identify Fur-regulated genes in the B. avium chromosome.

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Anti-biofilm activity of α-mangostin isolated from Garcinia mangostana L.

Zeitschrift für Naturforschung C ◽

10.1515/znc-2015-0187 ◽

2015 ◽

Vol 70 (11-12) ◽

pp. 313-318

Author(s):

Phuong T.M. Nguyen ◽

Bac H. Vo ◽

Nhung T. Tran ◽

Quyen D. Van

Keyword(s):

Dental Caries ◽

Streptococcus Mutans ◽

Causative Agent ◽

Biofilm Formation ◽

Vehicle Control ◽

Garcinia Mangostana ◽

Key Enzymes ◽

Surface Activities ◽

Topical Applications

Abstract This study was carried out to further examine the anti-biofilm activity of α-mangostin (αMG) isolated from Garcinia mangostana L. grown in Vietnam, against a strongly biofilm producing Streptococcus mutans, a major causative agent of dental caries. The obtained data indicated that topical applications (twice-daily, 60 s exposure each) of 150 μM αMG during biofilm formation on the surfaces of hydroxyapatite disks (sHA) by S. mutans UA159 resulted in 30.7% reduction in biofilm accumulation after 68 h of growth. The treatment did not affect the viability of S. mutans cells in the biofilms. The surface activities of two key enzymes responsible for biofilm formation, i.e. the glycosyltransferases GtfB and GtfC, were reduced by 20 and 35%, respectively (vs. vehicle control, P < 0.05). Interestingly, αMG specifically targeted S. mutans in mixed biofilms, resulting in the decrease of the S. mutans population and total biofilm biomass. αMG was also found to accumulate within the biofilm of S. mutans up to 4.5 μg/biofilm, equal to a concentration of >10 μM/biofilm. In conclusion, this study confirmed anti-biofilm activity of αMG against S. mutans. A brief exposure to αMG may suppress biofilm formation by targeting key enzymes imvolved in biofilm formation.

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The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia

Molecular Microbiology ◽

10.1111/j.1365-2958.2011.07814.x ◽

2011 ◽

Vol 82 (2) ◽

pp. 327-341 ◽

Cited By ~ 86

Author(s):

Mustafa Fazli ◽

Aileen O'Connell ◽

Martin Nilsson ◽

Karsten Niehaus ◽

J. Maxwell Dow ◽

...

Keyword(s):

Biofilm Formation ◽

Burkholderia Cenocepacia ◽

Respiratory Pathogen ◽

Family Protein

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Targeted Swabbing of Implant-Associated Biofilm Formation—A Staining-Guided Sampling Approach for Optimizing Routine Microbiological Diagnostics

Diagnostics ◽

10.3390/diagnostics11061038 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1038

Author(s):

Sylvio Redanz ◽

Andreas Enz ◽

Andreas Podbielski ◽

Philipp Warnke

Keyword(s):

Malachite Green ◽

Causative Agent ◽

Recovery Rate ◽

Biofilm Formation ◽

Elevated Risk ◽

Diagnostic Approach ◽

Time Saving ◽

Naked Eye ◽

Diagnostic Approaches ◽

Sampling Approach

Background: Swabbing of implants removed from potentially infected sites represents a time saving and ubiquitously applicable alternative to sonication approaches. The latter bears an elevated risk of processing related contaminations due to the high number of handling steps. Since biofilms are usually invisible to the naked eye, adequate swabbing relies on the chance of hitting the colonized area on the implant. A targeted directed swabbing approach could overcome this detriment. Method: Three dyes were tested at different concentrations for their toxicity on biofilm-associated cells of S. epidermidis, the species most frequently identified as a causative agent of implant-associated infections. Results: Malachite green (0.2%) delivered the highest bacterial recovery rates combined with the best results in biofilm visualization. Its suitability for diagnostic approaches was demonstrated for smooth and rough implant surfaces. Biofilm-covered areas were successfully visualized. Conclusion: Subsequent targeted swab-sampling resulted in a significantly increased bacterial recovery rate compared to a dye-free “random swabbing” diagnostic approach.

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Discovery, Purification, and Characterization of a Temperate Transducing Bacteriophage for Bordetella avium

Journal of Bacteriology ◽

10.1128/jb.182.21.6130-6136.2000 ◽

2000 ◽

Vol 182 (21) ◽

pp. 6130-6136 ◽

Cited By ~ 19

Author(s):

Celia B. Shelton ◽

David R. Crosslin ◽

Jennifer L. Casey ◽

S. Ng ◽

Louise M. Temple ◽

...

Keyword(s):

Gradient Centrifugation ◽

Respiratory Pathogen ◽

Contour Length ◽

Allelic Replacement ◽

Double Stranded Dna ◽

Bordetella Avium ◽

Transduction Frequency ◽

Generalized Transduction ◽

Insertion Mutations

ABSTRACT We discovered and characterized a temperate transducing bacteriophage (Ba1) for the avian respiratory pathogen Bordetella avium. Ba1 was initially identified along with one other phage (Ba2) following screening of four strains of B. avium for lysogeny. Of the two phage, only Ba1 showed the ability to transduce via an allelic replacement mechanism and was studied further. With regard to host range, Ba1 grew on six of nine clinical isolates ofB. avium but failed to grow on any tested strains ofBordetella bronchiseptica, Bordetella hinzii,Bordetella pertussis, or Bordetella parapertussis. Ba1 was purified by CsCl gradient centrifugation and was found to have an icosahedral head that contained a linear genome of approximately 46.5 kb (contour length) of double-stranded DNA and a contractile, sheathed tail. Ba1 readily lysogenized our laboratory B. avium strain (197N), and the prophage state was stable for at least 25 generations in the absence of external infection. DNA hybridization studies indicated the prophage was integrated at a preferred site on both the host and phage replicons. Ba1 transduced five distinctly different insertion mutations, suggesting that transduction was generalized. Transduction frequencies ranged from approximately 2 × 10−7 to 1 × 10−8 transductants/PFU depending upon the marker being transduced. UV irradiation of transducing lysates markedly improved transduction frequency and reduced the number of transductants that were lysogenized during the transduction process. Ba1 may prove to be a useful genetic tool for studying B. avium virulence factors.

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Isolation and characterization of infectious Vibrio parahaemolyticus, the causative agent of AHPND, from the whiteleg shrimp (Litopenaeus vannamei)

Latin American Journal of Aquatic Research ◽

10.3856/vol44-issue3-fulltext-5 ◽

2017 ◽

Vol 44 (3) ◽

pp. 470-479

Author(s):

Patricia López-León ◽

Antonio Luna-González ◽

Ruth Escamilla-Montes ◽

María del Carmen Flores-Miranda ◽

Jesús A. Fierro-Coronado ◽

...

Keyword(s):

Causative Agent ◽

Biofilm Formation ◽

Vibrio Parahaemolyticus ◽

Bacterial Strains ◽

Isolation And Characterization ◽

Commercial Farms ◽

Whiteleg Shrimp ◽

Acute Hepatopancreatic Necrosis Disease ◽

Selection Of

Vibrio parahaemolyticus, the causative agent of acute hepatopancreatic necrosis disease (AHPND), was isolated from the hepatopancreas of moribund whiteleg shrimp of commercial farms from Guasave, Sinaloa, Mexico. The isolates were screened on thiosulfate citrate bile salt sucrose agar plates for the selection of green colonies and further characterized through PCR with AP3 primers, 89F/R primers, hemolysin genes, hemolytic and enzymatic activity, hydrophobicity, autoaggregation, and biofilm formation. Bioassays by immersion challenge were conducted to confirm the pathogenicity of selected bacterial strains. In addition, the LC50 was calculated for each isolate. All isolates (35) belonged to V. parahaemolyticus, but three isolates did not correspond to strains that cause AHPND since they were negative with 89F/R primers. All isolates were αhemolytic and showed biofilm formation (from moderate to strong). Isolates were hydrophobic or hydrophilic and showed high autoaggregation capacity. Eight strains did not kill shrimp and eleven were pathogenic, but differences in virulence were found among them perhaps due to α-hemolysis and differences in biofilm formation and hydrophobicity. Therefore, performed characterization may help to understand the pathogenicity of V. parahaemolyticus. Finally, results showed that smaller shrimp are less resistant to V. parahaemolyticus infection.

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PORCINE CONTAGIOUS PLEUROPNEUMONIA

Journal of Experimental Medicine ◽

10.1084/jem.119.3.357 ◽

1964 ◽

Vol 119 (3) ◽

pp. 357-368 ◽

Cited By ~ 60

Author(s):

Richard E. Shope

Keyword(s):

Causative Agent ◽

Swine Influenza ◽

Respiratory Illness ◽

Respiratory Pathogen ◽

Epidemic Disease ◽

Experimental Conditions ◽

Porcine Contagious Pleuropneumonia ◽

Histopathological Studies

An acute frequently rapidly fatal respiratory illness occurring as an epidemic disease in Argentine swine has been shown to have a bacterium of the genus Hemophilus as its causative agent. This organism, for which the name Hemophilus pleuropneumoniae is suggested, causes a singular, fulminating pleuropneumonia in experimental swine. The very marked effectiveness of H. pleuropneumoniae as a respiratory pathogen contrasts strikingly with the relatively mild pathogenicity of the well known swine Hemophilus, H. influenzae suis, which, in concert with a virus, causes a less highly fatal respiratory ailment, swine influenza. Porcine contagious pleuropneumonia (PCP) is contagious under experimental conditions. In the pathogenesis of the disease, histopathological studies of early cases suggest that the lymphatics of the lung and pleura may be primarily involved and that the pneumonia and pleuritis then proceed from these initial sites of reaction.

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Response of Vibrio cholerae to Low-Temperature Shifts: CspV Regulation of Type VI Secretion, Biofilm Formation, and Association with Zooplankton

Applied and Environmental Microbiology ◽

10.1128/aem.00807-16 ◽

2016 ◽

Vol 82 (14) ◽

pp. 4441-4452 ◽

Cited By ~ 23

Author(s):

Loni Townsley ◽

Marilou P. Sison Mangus ◽

Sanjin Mehic ◽

Fitnat H. Yildiz

Keyword(s):

Low Temperature ◽

Vibrio Cholerae ◽

Causative Agent ◽

Biofilm Formation ◽

Cold Shock ◽

Diarrheal Disease ◽

Dependent Manner ◽

Natural Habitats ◽

Content Type ◽

Type Vi Secretion

ABSTRACTThe ability to sense and adapt to temperature fluctuation is critical to the aquatic survival, transmission, and infectivity ofVibrio cholerae, the causative agent of the disease cholera. Little information is available on the physiological changes that occur whenV. choleraeexperiences temperature shifts. The genome-wide transcriptional profile ofV. choleraeupon a shift in human body temperature (37°C) to lower temperatures, 15°C and 25°C, which mimic those found in the aquatic environment, was determined. Differentially expressed genes included those involved in the cold shock response, biofilm formation, type VI secretion, and virulence. Analysis of a mutant lacking the cold shock genecspV, which was upregulated >50-fold upon a low-temperature shift, revealed that it regulates genes involved in biofilm formation and type VI secretion. CspV controls biofilm formation through modulation of the second messenger cyclic diguanylate and regulates type VI-mediated interspecies killing in a temperature-dependent manner. Furthermore, a strain lackingcspVhad significant defects for attachment and type VI-mediated killing on the surface of the aquatic crustaceanDaphnia magna. Collectively, these studies reveal thatcspVis a major regulator of the temperature downshift response and plays an important role in controlling cellular processes crucial to the infectious cycle ofV. cholerae.IMPORTANCELittle is known about how human pathogens respond and adapt to ever-changing parameters of natural habitats outside the human host and how environmental adaptation alters dissemination.Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, experiences fluctuations in temperature in its natural aquatic habitats and during the infection process. Furthermore, temperature is a critical environmental signal governing the occurrence ofV. choleraeand cholera outbreaks. In this study, we showed thatV. choleraereprograms its transcriptome in response to fluctuations in temperature, which results in changes to biofilm formation and type VI secretion system activation. These processes in turn impact environmental survival and the virulence potential of this pathogen.

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Bacterial biofilm behavior in water-supply lines of dental units

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124811 ◽

1992 ◽

Vol 50 (1) ◽

pp. 882-883

Author(s):

B.D. Tall ◽

K.S. George ◽

R. T. Gray ◽

H.N. Williams

Keyword(s):

Water Supply ◽

Medical Devices ◽

Biofilm Formation ◽

Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

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Scanning electron microscopy of erythrophagocytosis by Entamoeba histolytica trophozoites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012480x ◽

1992 ◽

Vol 50 (1) ◽

pp. 880-881

Author(s):

Victor Tsutsumi ◽

Adolfo Martinez-Palomo ◽

Kyuichi Tanikawa

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Red Blood Cells ◽

Entamoeba Histolytica ◽

Causative Agent ◽

Blood Cells ◽

Protozoan Parasite ◽

Complex Phenomenon ◽

Great Capacity ◽

Scanning Electron

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis in man. The trophozoite or motile form is a highly dynamic and pleomorphic cell with a great capacity to destroy tissues. Moreover, the parasite has the singular ability to phagocytize a variety of different live or death cells. Phagocytosis of red blood cells by E. histolytica trophozoites is a complex phenomenon related with amebic pathogenicity and nutrition.

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