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Iranian Journal of Veterinary Research 2015A disease outbreak occurred in June 2012 among mud loach cultured on pond farms in Jangseong-gun, Jeollanam-do, Korea. Mortality rates reached up to 1.2% in the farm per...
A disease outbreak occurred in June 2012 among mud loach cultured on pond farms in Jangseong-gun, Jeollanam-do, Korea. Mortality rates reached up to 1.2% in the farm per day. Typical clinical signs were bleeding ulcer at the middle portion of head and haemorrhagic erosion of the operculum. Based on biochemical characteristics, the causative bacterium isolated from diseased fish was identified as Aeromonas sobria. The isolate expressed two haemolytic genes, aerolysin (sob) and haemolysin (asa1) genes. Histopathologically, liver showed hepatocellular vacuolar degeneration and congestion in sinusoids. The spleen exhibited necrotized splenocytes and haemorrhagic pulps. In the kidney, glomerular destruction, renal tubular necrosis and haemorrhage were observed. Experimental infection (infectious dose of 10(6), 10(7), and 10(8) cfu fish(-1)) of healthy mud loach with the isolate resulted in the development of clinical signs similar to those seen in the farm. By injection with an infectious dose of 10(6) cfu fish(-1), the mortality rate was 10.3% within 7 days post infection. A mortality rate of 60.9% was reached within 2 days when an infectious dose of 10(7) cfu fish(-1) was used. Otherwise, all fish died within 1 day when injected with 10(8) cfu fish(-1). The results demonstrated that A. sobria is involved in the morbidity and mortality of the farmed mud loach.
PubMed: 27175175
DOI: No ID Found -
Biological & Pharmaceutical Bulletin 2016In an attempt to discover inhibitory compounds against pore-forming toxins, some of the major toxins produced by bacteria, we herein examined the effects of four kinds...
Indolo[3,2-b]quinoline Derivatives Suppressed the Hemolytic Activity of Beta-Pore Forming Toxins, Aerolysin-Like Hemolysin Produced by Aeromonas sobria and Alpha-Hemolysin Produced by Staphylococcus aureus.
In an attempt to discover inhibitory compounds against pore-forming toxins, some of the major toxins produced by bacteria, we herein examined the effects of four kinds of indolo[3,2-b]quinoline derivatives on hemolysis induced by the aerolysin-like hemolysin (ALH) of Aeromonas sobria and also by the alpha-hemolysin of Staphylococcus aureus. The results showed that hemolysis induced by ALH was significantly reduced by every derivative, while that induced by alpha-hemolysis was significantly reduced by three out of the four derivatives. However, the degrees of reduction induced by these derivatives were not uniform. Each derivative exhibited its own activity to inhibit the respective hemolysin. Compounds 1 and 2, which possessed the amino group bonding the naphthalene moiety at the C-11 position of indolo[3,2-b]quinoline, had strong inhibitory effects on the activity of ALH. Compound 4 which consisted of benzofuran and quinoline had strong inhibitory effects on the activity of alpha-hemolysin. These results indicated that the amino group bonding the naphthalene moiety of compounds 1 and 2 assisted in their ability to inhibit ALH activity, while the oxygen atom at the 10 position of compound 4 strengthened its interaction with alpha-hemolysin. These compounds also suppressed the hemolytic activity of the supernatant of A. sobria or A. hydrophila, suggesting that these compounds were effective at the site of infection of these bacteria.
Topics: Aeromonas; Animals; Bacterial Toxins; Erythrocytes; Hemolysin Proteins; Hemolysis; Molecular Structure; Quinolines; Sheep
PubMed: 26725434
DOI: 10.1248/bpb.b15-00708 -
Veterinaria Italiana 2015The rapid rise in the number of pet chelonians and their illegal trade can modify the ecology, involving exotic pets, humans, and microbiological agents. Therefore,...
The rapid rise in the number of pet chelonians and their illegal trade can modify the ecology, involving exotic pets, humans, and microbiological agents. Therefore, different epidemiological situations and the related risk to introduce and spread infectious diseases, especially zoonotic agents, have to be considered. The aim of this study was to investigate the microbiological and parasitological situation in 2 chelonian facilities (a private breeding of tortoises and a shelter for turtles) collecting oral/cloacal swabs and cloacal flushes to research viruses, bacteria, and parasites. No Chelonian Herperviruses, Cryptosporidium spp., and Giardia spp. infections were found. Salmonella spp. were detected in 8% of tortoises and in 37.5% of turtles and oxyurid eggs in 23.7% of tortoises and 15% of turtles; ascarid eggs were present only in tortoises. Moreover, 6 turtles showed cutaneous lesions, where Aeromonas sobria was isolated as main pathogen. Further studies should be performed to understand the zoonotic and infectious risk in each chelonian facility and to characterize the variables that could influence the microbiological patterns.
Topics: Animals; Italy; Turtles
PubMed: 26344661
DOI: 10.12834/VetIt.7.21.3 -
International Journal of Molecular... May 2015Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals...
Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in fish. In this report, a MR gene (designated as zfMR) was cloned from zebra fish (Danio rerio), which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected zebra fish. The established zebra fish-A. sobria infection model will be valuable for elucidating the role of MR in fish immune responses to infection.
Topics: Aeromonas hydrophila; Amino Acid Sequence; Animals; Cloning, Molecular; Gram-Negative Bacterial Infections; Humans; Immunohistochemistry; Interleukin-1beta; Intestinal Mucosa; Kidney; Lectins, C-Type; Liver; Mannose Receptor; Mannose-Binding Lectins; Molecular Sequence Data; Phylogeny; RNA, Messenger; Real-Time Polymerase Chain Reaction; Receptors, Cell Surface; Sequence Alignment; Spleen; Tumor Necrosis Factor-alpha; Zebrafish
PubMed: 25988382
DOI: 10.3390/ijms160510997 -
The Journal of Biological Chemistry Apr 2015Subtilisin-like proteases are broadly expressed in organisms ranging from bacteria to mammals. During maturation of these enzymes, N-terminal propeptides function as...
Subtilisin-like proteases are broadly expressed in organisms ranging from bacteria to mammals. During maturation of these enzymes, N-terminal propeptides function as intramolecular chaperones, assisting the folding of their catalytic domains. However, we have identified an exceptional case, the serine protease from Aeromonas sobria (ASP), that lacks a propeptide. Instead, ORF2, a protein encoded just downstream of asp, appears essential for proper ASP folding. The mechanism by which ORF2 functions remains an open question, because it shares no sequence homology with any known intramolecular propeptide or other protein. Here we report the crystal structure of the ORF2-ASP complex and the solution structure of free ORF2. ORF2 consists of three regions: an N-terminal extension, a central body, and a C-terminal tail. Together, the structure of the central body and the C-terminal tail is similar to that of the intramolecular propeptide. The N-terminal extension, which is not seen in other subtilisin-like enzymes, is intrinsically disordered but forms some degree of secondary structure upon binding ASP. We also show that C-terminal (ΔC1 and ΔC5) or N-terminal (ΔN43 and ΔN64) deletion eliminates the ability of ORF2 to function as a chaperone. Characterization of the maturation of ASP with ORF2 showed that folding occurs in the periplasmic space and is followed by translocation into extracellular space and dissociation from ORF2, generating active ASP. Finally, a PSI-BLAST search revealed that operons encoding subtilases and their external chaperones are widely distributed among Gram-negative bacteria, suggesting that ASP and its homologs form a novel family of subtilases having an external chaperone.
Topics: Aeromonas; Bacterial Proteins; Molecular Chaperones; Mutation; Protein Structure, Tertiary; Serine Proteases; Structure-Activity Relationship
PubMed: 25784551
DOI: 10.1074/jbc.M114.622852 -
Journal of Medical Case Reports Sep 2014Aeromonas veronii biovar sobria is a rare cause of bacteremia, with several studies indicating that this isolate may be of particular clinical significance since it is... (Review)
Review
INTRODUCTION
Aeromonas veronii biovar sobria is a rare cause of bacteremia, with several studies indicating that this isolate may be of particular clinical significance since it is enterotoxin producing. A wide spectrum of infections has been associated with Aeromonas species in developing countries that include gastroenteritis, wound infections, septicemia and lung infections. This infection, caused by Aeromonas species, is usually more severe in immunocompromised than immunocompetent individuals. We here describe a case of soft tissue infection and severe sepsis due to Aeromonas sobria in an immunocompromised patient.
CASE PRESENTATION
A 74-year-old Caucasian man with a clinical history of chronic lymphocytic leukemia and immune thrombocytopenia, periodically treated with steroids, was admitted to our Intensive Care Unit because of necrotizing fasciitis and multiorgan failure due to Aeromonas sobria, which resulted in his death. The unfortunate coexistence of a Candida albicans infection played a key role in the clinical course.
CONCLUSION
Our experience suggests that early recognition and aggressive medical and surgical therapy are determinants in the treatment of severe septicemia caused by an Aeromonas sobria in an immunocompromised patient.
Topics: Aeromonas; Aged; Fasciitis, Necrotizing; Fatal Outcome; Humans; Immunocompromised Host; Leg; Male; Multiple Organ Failure; Radiography; Sepsis; Soft Tissue Infections
PubMed: 25245365
DOI: 10.1186/1752-1947-8-315 -
Aquatic Biosystems 2014Seabirds have been historically used to monitor environmental contamination. The aim of the present study was to test the suitability of a species belonging to the...
INTRODUCTION
Seabirds have been historically used to monitor environmental contamination. The aim of the present study was to test the suitability of a species belonging to the Procellariiformes group, the Manx shearwater, Puffinus puffinus, as a sentinel of environmental health, by determining contaminant levels (trace metals and organochlorine compounds) from carcass tissues and by isolating Vibrio spp. and Aeromonas spp. from live specimens. To this end, 35 Puffinus puffinus carcasses wrecked on the north-central coast of the state of Rio de Janeiro, Brazil, and two carcasses recovered in Aracruz, on the coast of the state of Espírito Santo, Brazil, were sampled, and fragments of muscle and hepatic tissues were collected for contaminant analyses. Swabs from eleven birds found alive at the north-central coast of Rio de Janeiro were collected for isolation of the aforementioned bacteria.
RESULTS
THE AVERAGE CONCENTRATION IN DRY WEIGHT (DW) OF THE TRACE METALS WERE: mercury 7.19 mg kg(-1)(liver) and 1.23 mg kg(-1) (muscle); selenium 34.66 mg kg(-1) (liver) and 7.98 mg kg(-1) (muscle); cadmium 22.33 mg kg(-1) (liver) and 1.11 mg kg(-1) (muscle); and lead, 0.1 mg kg(--1) (liver) and 0.16 mg kg(-1) (muscle). Organochlorine compounds were detected in all specimens, and hexachlorbiphenyls, heptachlorbiphenyls and DDTs presented the highest levels. Regarding microbiological contamination, bacteria from the Vibrio genus were isolated from 91% of the analyzed specimens. Vibrio harveyi was the predominant species. Bacteria from the Aeromonas genus were isolated from 18% of the specimens. Aeromonas sobria was the only identified species.
CONCLUSIONS
The results indicate that Puffinus puffinus seems to be a competent ocean health sentinel. Therefore, the monitoring of contaminant levels and the isolation of public health interest bacteria should proceed in order to consolidate this species importance as a sentinel.
PubMed: 25191536
DOI: 10.1186/2046-9063-10-6