Pyrogens fail to produce fever in a cordylid lizard

1981 ◽  
Vol 241 (3) ◽  
pp. R198-R202 ◽  
Author(s):  
H. P. Laburn ◽  
D. Mitchell ◽  
E. Kenedi ◽  
G. N. Louw
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Aeromonas Hydrophila ◽  
Thermal Gradient ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Sterile Saline ◽  
Rabbit Blood ◽  
Preferred Body Temperature

We investigated the effects on body temperature of the lizard Cordylus cataphractus of intracardiac injections of leucocyte pyrogen (LP) synthesized from rabbit blood and of killed Aeromonas hydrophila, a gram-negative bacterium reputed to be pathogenic in lizards. Lizards were placed in a photothermal gradient that allowed them to select a preferred body temperature following the injections. Neither injection of 0.5 ml rabbit LP nor of 4 X 10(9) organisms of A. hydrophila in 0.2 ml sterile saline caused body temperature of lizards to differ from that of control lizards injected with sterile saline. Following injection of these solutions in the lizards placed in a thermal gradient where ambient temperature ranged from 20-88 degrees C, body temperature was maintained between 32 and 34 degrees C. Pyrogens failed to elevate body temperature even when body temperature was elevated artificially to 36 degrees C before injection. We conclude that C. cataphractus does not respond with fever to either rabbit LP or A. hydrophila. Fever may not be ubiquitous even among lizards.

Silver Oxide–Copper Oxide Nanocomposite Preparation and Antimicrobial Activity as a Source for the Treatment of Fish Diseases

2017 ◽  
pp. 140-151
Author(s):  
Sayed Reza Shaffiey ◽  
Sayedeh Fatemeh Shaffiey
Keyword(s):  
Aeromonas Hydrophila ◽  
Bacterial Infections ◽  
Antimicrobial Activities ◽  
Cuo Nanoparticles ◽  
Negative Bacterium ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
Gram Negative ◽  
Transmission Electron ◽  
Scanning Electron

Aeromonas hydrophila is a heterotrophic, gram negative bacterium which is primary or secondary cause of ulcers, fin rot, tail rot, and hemorrhagic septicaemia in fish. The treatments for this infection are only restricted to some antibiotics. So, novel materials are being searched for combating with bacterial infections and the resulting consequences. In this chapter, Ag2O/CuO nanocomposites were synthesized chemically and characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and transmission electron microscope (TEM). The antimicrobial activities of Ag2O/CuO nanoparticles (NPs), was checked by both well diffusion and turbidometric (spectrophotometric) method. Synthesized nanoparticles exhibited their antimicrobial efficacy in both the standard inhibitory assays; these results thus provide a scope for further research on the application of Ag2O/CuO nanoparticles as disinfectant and/or antibiotic in the fishery industry.

scholarly journals A Case of Mortality Caused by Aeromonas hydrophila in Wild-Caught Red-Eyed Crocodile Skinks (Tribolonotus gracilis)

2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Jun Kwon ◽  
Sang Guen Kim ◽  
Sang Wha Kim ◽  
Saekil Yun ◽  
Hyoun Joong Kim ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Opportunistic Infections ◽  
Clinical Symptoms ◽  
Human Medicine ◽  
Aquatic Environments ◽  
Negative Bacterium ◽  
Severe Stress ◽  
Antimicrobial Susceptibility Test ◽  
Gram Negative ◽  
In The Wild

Aeromonas hydrophila, a Gram-negative bacterium commonly found in aquatic environments, is pathogenic to amphibians, reptiles, and mammals. In human medicine, the clinical symptoms of aeromonad infection include not only gastroenteritis but also extraintestinal infections, such as wounds, cellulitis, and septicemia, in immunocompromised and immunocompetent individuals. In this study, ten red-eyed crocodile skinks (Tribolonotus gracilis) that shared the same space were found dead 7 days after being shipped from Indonesia. The necropsy revealed A. hydrophila to be the causative agent, and the isolates were susceptible to most antibiotics, based on an antimicrobial susceptibility test. Seven virulence factors (act, ast, alt, aerA, fla, gcaT, and ahyB) considered to be associated with virulence were detected by PCR. Microscopic examination revealed several necrotic lesions and melano-macrophage centers in the tissue slides. Reptiles caught in the wild for trade experience captivity stress. Furthermore, in the winter, reptiles are easily exposed to the cold atmosphere. These stresses can negatively impact the immunity of these ectotherms, making them vulnerable to A. hydrophila infections. Therefore, to avoid such opportunistic infections and mortality following exposure to severe stress, medical care is recommended. The studies of alternatives, such as bacteriophage and bacteriocin, are needed for a preventive application.

Antipyretic effect of arginine vasotocin in toads

2000 ◽  
Vol 278 (6) ◽  
pp. R1408-R1414 ◽  
Author(s):  
K. C. Bicego-Nahas ◽  
A. A. Steiner ◽  
E. C. Carnio ◽  
J. Antunes-Rodrigues ◽  
L. G. S. Branco
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Temperature ◽  
Thermal Gradient ◽  
Arginine Vasotocin ◽  
Antipyretic Effect ◽  
The Central Nervous System ◽  
Preferred Body Temperature ◽  
Toad Bufo

Arginine vasotocin (AVT) is a nonmammalian analog of the mammalian hormone arginine vasopressin (AVP). These peptides are known for their antidiuretic and pressor effects. More recently, AVP has been recognized as an important antipyretic molecule in mammals. However, no information exists about the role of AVT in febrile ectotherms. We tested the hypothesis that AVT is an antipyretic molecule in the toad Bufo paracnemis. Toads equipped with a temperature probe were placed in a thermal gradient, and preferred body temperature was recorded continuously. A behavioral fever was observed after lipopolysaccharide (LPS) was injected systemically (200 μg/kg). Systemically injected AVT (300 pmol/kg) alone caused no significant change in body temperature, but abolished LPS-induced fever. Moreover, a smaller dose of AVT (10 pmol/kg), which did not affect LPS-induced fever when injected peripherally, abolished fever when injected intracerebroventricularly. We therefore conclude that AVT plays an antipyretic role in the central nervous system, by means of behavior, in an ectotherm, a fact consistent with the notion that AVT/AVP elicits antipyresis by reducing the thermoregulatory set point.

Indomethacin impairs LPS-induced behavioral fever in toads

2002 ◽  
Vol 93 (2) ◽  
pp. 512-516 ◽  
Author(s):  
K. C. Bicego ◽  
A. A. Steiner ◽  
J. Antunes-Rodrigues ◽  
L. G. S. Branco
Keyword(s):  
Body Temperature ◽  
Thermal Gradient ◽  
Behavioral Thermoregulation ◽  
Cyclooxygenase Inhibitor ◽  
Set Point ◽  
Behavioral Fever ◽  
Preferred Body Temperature ◽  
Baseline Values ◽  
Toad Bufo

We tested the hypothesis that PGs mediate lipopolysaccharide (LPS)-induced behavioral fever in the toad Bufo paracnemis. Measurements of preferred body temperature (Tb) were performed with a thermal gradient. Toads were injected intraperitoneally with the cyclooxygenase inhibitor indomethacin (5 mg/kg), which inhibits PG biosynthesis, or its vehicle (Tris) followed 30 min later by LPS (0.2 and 2 mg/kg) into the lymph sac. LPS at the dose of 0.2 mg/kg caused a significant increase in Tb from 7 to 10 h after injection, and then Tb returned toward baseline values. LPS at the dose of 2 mg/kg produced a different pattern of response, with a longer latency to the onset of fever (10th h) and a longer duration (until the end of the experiment at the 15th h). Tris significantly attenuated the fever induced by LPS at 0.2 mg/kg, but not at 2 mg/kg. Moreover, indomethacin completely blocked the fever evoked by LPS (2 mg/kg). These results indicate that the behavioral fever induced by LPS in toads requires the activation of the COX pathway, suggesting that the involvement of PG in fever has an ancient phylogenetic history and that endogenous PGs raise the thermoregulatory set point to produce fever, because behavioral thermoregulation seems to be related to changes in the thermoregulatory set point.

scholarly journals Draft Genome Sequences of Three Aeromonas hydrophila Isolates from Catfish and Tilapia

2017 ◽  
Vol 5 (3) ◽  
Author(s):  
Hasan C. Tekedar ◽  
Salih Kumru ◽  
Safak Kalindamar ◽  
Attila Karsi ◽  
Geoffrey C. Waldbieser ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Draft Genome ◽  
Negative Bacterium ◽  
Genome Sequences ◽  
Gram Negative ◽  
Content Type ◽  
Severe Infections ◽  
Freshwater Environments

ABSTRACT Aeromonas hydrophila is a Gram-negative bacterium that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here, we report the draft genomes of three A. hydrophila catfish and tilapia isolates.

scholarly journals Massiliamide, a cyclic tetrapeptide with potent tyrosinase inhibitory properties from the Gram-negative bacterium Massilia albidiflava DSM 17472T

2020 ◽  
Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross
Keyword(s):  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Liquid Culture ◽  
Spectroscopic Analysis ◽  
2D Nmr ◽  
Negative Bacterium ◽  
Gram Negative ◽  
The Absolute ◽  
Potent Inhibitory Activity ◽  
Cyclic Tetrapeptide

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.

scholarly journals Porphyromonas gingivalis fimbrial protein Mfa5 contains a von Willebrand factor domain and an intramolecular isopeptide

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Thomas V. Heidler ◽  
Karin Ernits ◽  
Agnieszka Ziolkowska ◽  
Rolf Claesson ◽  
Karina Persson
Keyword(s):  
Porphyromonas Gingivalis ◽  
Von Willebrand Factor ◽  
Host Cells ◽  
Negative Bacterium ◽  
Oral Biofilm ◽  
Gram Negative ◽  
Type V ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Fimbrial Protein

AbstractThe Gram-negative bacterium Porphyromonas gingivalis is a secondary colonizer of the oral biofilm and is involved in the onset and progression of periodontitis. Its fimbriae, of type-V, are important for attachment to other microorganisms in the biofilm and for adhesion to host cells. The fimbriae are assembled from five proteins encoded by the mfa1 operon, of which Mfa5 is one of the ancillary tip proteins. Here we report the X-ray structure of the N-terminal half of Mfa5, which reveals a von Willebrand factor domain and two IgG-like domains. One of the IgG-like domains is stabilized by an intramolecular isopeptide bond, which is the first such bond observed in a Gram-negative bacterium. These features make Mfa5 structurally more related to streptococcal adhesins than to the other P. gingivalis Mfa proteins. The structure reported here indicates that horizontal gene transfer has occurred among the bacteria within the oral biofilm.

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