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Zentralblatt Fur Bakteriologie :... Apr 1991The cellular fatty acids of 39 strains belonging to the genus Aeromonas (Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Aeromonas media, Aeromonas schubertii,...
The cellular fatty acids of 39 strains belonging to the genus Aeromonas (Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Aeromonas media, Aeromonas schubertii, Aeromonas veronii) were determined by high resolution gas-liquid chromatography. The fatty acid profiles were characterized by major amounts (60% or more) of one saturated (hexadecanoic acid = 16:0) and two unsaturated (hexadecenoic acid = 16:1 and octadecenoic acid = 18:1) acids. While the majority of the strains of the six species exhibited, qualitatively, very similar fatty acid compositions, only minor and inconsistent differences could be observed which would be useful for a distinction of the different taxons. The following fatty acids were qualitatively identified: 12:0, i-13:0, 14:0, 3-OH 13:0, i-15:0, 15:0, 2-OH 14:0, 3-OH 14:0, i-16:0, 16:1, 16:0, i-17:1, i-17:0, a-17:0, 17:0 cyclopropane, 17:1, 17:0, 18:1 (3 isomers), 18:0 and i-20:0. Excellent congruence was found in reproducibility studies. Fatty acid analyses show a great homogeneity within the group and the technique does not appear to be the ideal method in distinguishing between Aeromonas species.
Topics: Aeromonas; Chromatography, Gas; Esters; Fatty Acids; Humans; Reproducibility of Results; Water Microbiology
PubMed: 1930556
DOI: 10.1016/s0934-8840(11)80762-0 -
International Journal of Food... Oct 2001A range of commercially available organic vegetables (n = 86) was examined for the presence of Salmonella, Campylobacter, Escherichia coli, E. coli O 157. Listeria and...
A range of commercially available organic vegetables (n = 86) was examined for the presence of Salmonella, Campylobacter, Escherichia coli, E. coli O 157. Listeria and Aeromonas spp., to provide information on the occurrence of such organisms in organic vegetables in Northern Ireland. The study was not designed to quantify such organisms or to compare occurrence with conventionally farmed vegetables. Standard enrichment techniques were used to isolate and identify enteric pathogens and Aeromonas species. No Salmonella, Campylobacter, E. coli. E. coli O 157, Listeria were found in any of the samples examined. Aeromonas species were isolated from 34% of the total number of organic vegetables examined. Many (64%) of the organic vegetables examined were "ready-to-eat" after minimal processing, i.e., washing. Aeromonas spp. was isolated from 41% of these vegetables. Aeromonas spp. was not recovered from certain vegetable types. The most commonly isolated species of Aeromonas was Aeromonas schubertii with 21.0% of all samples contaminated with this species; 5.8% of samples contained A. hydrophila, 5.8% A. trota, 3.5% A. caviae and 2.3% contained A. veronii biovar veronii. Although Aeromonas species are frequently detected in organic vegetables, the absence of accepted enteric pathogens was encouraging, and does not support the allegation of organic foods being of high risk due to the farming methods used.
Topics: Aeromonas; Agriculture; Campylobacter; Colony Count, Microbial; Escherichia coli; Escherichia coli O157; Food Microbiology; Food, Organic; Ireland; Salmonella; Vegetables
PubMed: 11759753
DOI: 10.1016/s0168-1605(01)00535-9 -
Fish & Shellfish Immunology Aug 2022As an inflammatory cytokine of the interleukin-20 (IL-20) subfamily, IL-20 has various functions in immune defenses, inflammatory diseases, tissue regeneration, cancer,...
Molecular identification and functional exploration of interleukin-20 in snakehead (Channa argus) involved in bacterial invasion and the proliferation of head kidney leukocytes.
As an inflammatory cytokine of the interleukin-20 (IL-20) subfamily, IL-20 has various functions in immune defenses, inflammatory diseases, tissue regeneration, cancer, and metabolism. Although the characteristics and functions of mammalian IL-20 have been clarified, those of fish IL-20 remain unclear. In this study, the IL-20 gene from the snakehead Channa argus (shIL-20) was cloned and functionally characterized. Similar to the IL-20 homologues of other species, the shIL-20 has a five exon/four intron structure in the coding region. The open reading frame of shIL-20 consists of 528 base pairs and encodes 175 amino acids (aa), including a signal peptide (aa 1-24) and a mature peptide (aa 25-175). The mature shIL-20 protein has six conserved cysteine residues, which occur in the IL-20 proteins of all species analyzed, and an additional cysteine residue (Cys-82) found only in the IL-20 proteins of several teleosts. The modeled tertiary structure of shIL-20 is similar with that of Homo sapiens IL-20. The shIL-20 was expressed constitutively in all the tissues analyzed, and its transcription was induced in the spleen and head kidney by Aeromonas schubertii and Nocardia seriolae in vivo and in head kidney leukocytes (HKLs) by lipoteichoic acid, lipopolysaccharide, and polyinosinic-polycytidylic acid in vitro. The recombinant shIL-20 protein induced the transcription of tumor necrosis factor α1 (TNF-α1), TNF-α2, IL-1β, and endogenous shIL-20, and promoted the proliferation of HKLs. In conclusion, these findings demonstrate that shIL-20 participates in the immune response to bacterial invasion and promotes leukocyte proliferation, offering new insights into the functions of fish IL-20 during pathogen invasion.
Topics: Animals; Bacteria; Cell Proliferation; Cysteine; Fish Diseases; Fish Proteins; Fishes; Head Kidney; Interleukins; Leukocytes; Mammals; Phylogeny
PubMed: 35810964
DOI: 10.1016/j.fsi.2022.07.005 -
International Journal of Biological... Nov 2013Hexaoligochitin produced by chitinase, ASCHI61, from Aeromonas schubertii was recently expressed. In this work, the optimal conditions for the mass production of ASCHI61...
Hexaoligochitin produced by chitinase, ASCHI61, from Aeromonas schubertii was recently expressed. In this work, the optimal conditions for the mass production of ASCHI61 were investigated. The efficiency of recombinant protein expression in Escherichia coli was determined by various parameters, including the pH of the culture medium, induction temperature, shaking speed, inducer concentration, and induction period. The optimization experiments could be simplified through a statistical design of experiments (response surface methodology). From the fractional factorial design, the interactive effect of induction temperature and time was the most significant. The total activity of the enzyme was 32,092 U at 23.9 °C with 115 min of induction. Under those conditions, the total activity of the recombinant protein was 30,650 U in the fermentation experiments, with an error of only 4.8%. The total activity of ASCHI61 increased 1.54-fold under the optimal conditions. Based on the results, ASCHI61 can be expressed more for hexaoligochitin production.
Topics: Batch Cell Culture Techniques; Chitin; Chitinases; Escherichia coli; Fermentation; Recombinant Proteins; Reproducibility of Results
PubMed: 24099937
DOI: 10.1016/j.ijbiomac.2013.09.048 -
Fish & Shellfish Immunology Sep 2020Tumor necrosis factor-α (TNF-α) is a pluripotent mediator of pro-inflammatory and antimicrobial defense mechanisms and a regulator of lymphoid organ development....
Tumor necrosis factor-α (TNF-α) is a pluripotent mediator of pro-inflammatory and antimicrobial defense mechanisms and a regulator of lymphoid organ development. Although two types of TNF-α have been identified in several teleost species, their functions in pathogen infection remain largely unexplored, especially in pathogen clearance. Herein, we cloned and characterized two types of TNF-α, termed shTNF-α1 and shTNF-α2, and their receptors, shTNFR1 and shTNFR2, from snakehead (Channa argus). These genes were constitutively expressed in all tested tissues, and were induced by Aeromonas schubertii and Nocardia seriolae in head kidney and spleen in vivo, and by lipoteichoic acid (LTA), lipopolysaccharides (LPS), and Polyinosinic-polycytidylic acid [Poly (I:C)] in head kidney leukocytes (HKLs) in vitro. Moreover, recombinant shTNF-α1 and shTNF-α2 upregulated the expression of endogenous shTNF-α1, shTNF-α2, shTNFR1, and shTNFR2, and enhanced intracellular bactericidal activity, with shTNF-α1 having a greater effect than shTNF-α2. These findings suggest important roles of fish TNFα1, TNFα2, and their receptors in bacterial infection and pathogen clearance, and provide a new insight into their function in antibacterial innate immunity.
Topics: Aeromonas; Animals; Fish Diseases; Fish Proteins; Fishes; Gram-Negative Bacterial Infections; Head Kidney; Immunity, Innate; Leukocytes; Lipopolysaccharides; Nocardia; Nocardia Infections; Poly I-C; Receptors, Tumor Necrosis Factor; Spleen; Teichoic Acids; Tumor Necrosis Factor-alpha
PubMed: 32585357
DOI: 10.1016/j.fsi.2020.05.059 -
Fish & Shellfish Immunology Apr 2022Interleukin-21 (IL-21), a crucial immune regulatory molecule, belongs to the common γ-chain family of type I cytokines, and exerts pleiotropic effects on multiple...
Characterization of snakehead (Channa argus) interleukin-21: Involvement in immune defense against two pathogenic bacteria, in leukocyte proliferation, and in activation of JAK-STAT signaling pathway.
Interleukin-21 (IL-21), a crucial immune regulatory molecule, belongs to the common γ-chain family of type I cytokines, and exerts pleiotropic effects on multiple immune cell types in mammals. However, the characteristics and functions of fish IL-21 remain unclear. To further investigate the molecular mechanism of IL-21 in teleosts, we first cloned and identified the IL-21 gene (designated shIL-21) of the snakehead (Channa argus). The full-length open reading frame of shIL-21 is 438 bp in length, and encodes a predicted protein of 145 amino acid residues. A sequence analysis showed that shIL-21 has the typical structural characteristics of other IL-21 proteins, containing four α-helices and four conserved cysteine residues. In a phylogenetic analysis, shIL-21 clustered within a subgroup of IL-21 proteins from other teleost species and shared its closest evolutionary relationship with that of Lates calcarifer. The expression analysis showed that shIL-21 was ubiquitously expressed in all the healthy snakehead tissues tested, albeit at different levels. After infection with Nocardia seriolae or Aeromonas schubertii, the relative expression of shIL-21 was mainly upregulated in the head kidney and spleen in vivo. Similarly, after stimulation with the three pathogen analogues lipoteichoic acid, lipopolysaccharides, and polyinosinic-polycytidylic acid, the expression of shIL-21 was also induced in head kidney leukocytes in vitro. A recombinant shIL-21 protein was expressed and purified, and promoted the proliferation of head kidney leukocytes, induced the expression of genes encoding critical signaling molecules in the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway, including JAK1, JAK3, STAT1, and STAT3, and induced the expression of endogenous shIL-21 and genes encoding several key proinflammatory cytokines (tumor necrosis factor-α, interferon-γ, and IL-1β). Taken together, these preliminary findings suggest that shIL-21 is involved in the immune defense against bacterial infection, in leukocyte proliferation, and in the activation of the JAK-STAT pathway. They thus extend the functional studies of IL-21 in teleosts.
Topics: Animals; Cell Proliferation; Fish Diseases; Fishes; Interleukins; Janus Kinases; Leukocytes; Mammals; Phylogeny; STAT Transcription Factors; Signal Transduction
PubMed: 35278639
DOI: 10.1016/j.fsi.2022.03.006 -
Journal of Food Protection May 2001Numbers and species of motile Aeromonas were determined in freshly caught freshwater fish, in the surrounding environment, and also during iced chilled storage of fish... (Comparative Study)
Comparative Study
Numbers and species of motile Aeromonas were determined in freshly caught freshwater fish, in the surrounding environment, and also during iced chilled storage of fish specimens. Although no significant differences were observed in water samples, initial levels for skin, gill, and intestines were significantly lower in farmed rainbow trout (Oncorhynchus mykiss) than in wild brown trout (Salmo trutta) and pike (Esox lucius). During storage of wild specimens, naturally occurring aeromonads grew fairly well on the surfaces of skin and body cavity. Of 171 strains assigned to the genus Aeromonas, 88% were identified to phenospecies and putative genospecies level by using comprehensive biochemical schemes. The isolates were allocated to putative hybridization groups (HGs) 1 and 3 Aeromonas hydrophila (29%); putative HG 8 Aeromonas veronii biovar sobria (19%); putative HG 2 Aeromonas bestiarum (18%); putative HG 9 Aeromonas jandaei (16%); putative HGs 4 and 5a Aeromonas caviae (2%); putative HG 12 Aeromonas schubertii (2%); and putative HG 11 (unnamed, 0.6%). The remaining 20 isolates (12%) resembled A. schubertii but could not be allocated to currently recognized phenospecies or to putative HGs. Although cultured rainbow trout yielded strains of putative HGs 1, 4, and 8, which appear to be of major clinical importance, most isolates assigned to putative HGs 1 and 8 were recovered from pike. Differences among HGs found in wild animals could be related to their origin (unpolluted rivers for brown trout and urban rivers for pike). The recovery of these aeromonads species was not related to sampling site. The initial levels of motile aeromonads, their behavior during storage, and the strong potential spoilage activity of most isolates confirm that these bacteria can contribute to deterioration of iced wild freshwater fish. Although adequate cooking would inactivate motile aeromonads, the high incidence of isolates belonging to gastroenteritis-associated HGs should be regarded as a potential health concern, particularly for susceptible populations when there is a possibility of cross-contamination.
Topics: Aeromonas; Animals; Animals, Wild; Aquaculture; Esocidae; Fishes; Trout; Water Microbiology
PubMed: 11348001
DOI: 10.4315/0362-028x-64.5.687 -
Journal of Food Protection May 2006Even though worldwide production of rabbit meat is >1,000,000 tons, little information is available for rabbit meat microbiology. This study provides data on the...
Even though worldwide production of rabbit meat is >1,000,000 tons, little information is available for rabbit meat microbiology. This study provides data on the prevalence of Salmonella, Escherichia coli O157:H7, Yersinia enterocolitica, Listeria spp., motile Aeromonas spp., and Staphylococcus aureus on rabbit meat. A total of 24 rabbit carcasses from two abattoirs and 27 rabbit meat packages from supermarket displays were examined. In addition to culturing methods, associated virulence genes were investigated by PCR in suspect isolates and samples. Neither Salmonella nor E. coli O157:H7 was detected. All samples were negative for virulence-associated invA, stx1, and stx2 genes. At one abattoir, two carcasses (3.9%) carried Y. enterocolitica yst-, and two were positive for the yst gene, although viable Y. enterocolitica cells were not recovered from these samples. Seven samples (13.7%) were contaminated with Listeria. Of them, three were positive for hly and iap genes (Listeria monocytogenes hly+ / iap+), two carried Listeria seeligeri, one carried Listeria ivanovii, and one carried Listeria innocua. For detectable motile Aeromonas spp. (average count, 1.77 +/- 0.62 log CFU/g), the contamination rate was 35.3%, although ca. 90% of the samples were positive for the aerA and/or hlyA genes. The majority of aeromonad isolates were Aeromonas hydrophila aerA+ / hlyA+. Aeromonas caviae, Aeromonas popoffii, Aeromonas schubertii, and the two biovars of Aeromonas veronii were also isolated. The prevalence of S. aureus contamination (average count, 1.37 +/- 0.79 log CFU/g) was 52.9%. Among 27 S. aureus isolates, two harbored genes for staphylococcal enterotoxin B (seb), and two harbored genes for staphylococcal enterotoxin C (sec). The remaining isolates were negative for sea, seb, sec, sed, and see.
Topics: Abattoirs; Aeromonas; Animals; Bacterial Typing Techniques; Colony Count, Microbial; Commerce; Consumer Product Safety; Escherichia coli O157; Food Contamination; Food Handling; Humans; Listeria; Meat; Polymerase Chain Reaction; Rabbits; Salmonella; Staphylococcus aureus; Yersinia enterocolitica
PubMed: 16715811
DOI: 10.4315/0362-028x-69.5.1106 -
Journal of Food Protection Jan 1993A total of 35 samples (1000 ml each) of pasteurized milk and 25 samples (100 g each) of white cheese purchased at supermarkets in Rio de Janeiro were analyzed for the...
A total of 35 samples (1000 ml each) of pasteurized milk and 25 samples (100 g each) of white cheese purchased at supermarkets in Rio de Janeiro were analyzed for the presence of Aeromonas . Strains of Aeromonas were isolated from 28.5% of pasteurized milk and 32% of white cheese samples. Standard Plate counts in the pasteurized milk samples ranged from 7.2 × 10 to 2.5 × 10 CFU/ml. Total and fecal coliform counts in white cheese samples ranged from 1.9 × 10 to 2.4 × 10 most probable number per g and 3.2 × 10 to 1.2 × 10 most probable number per g, respectively. It was possible to identify Aeromonas caviae (58.9%), Aeromonas hydrophila (12.8%), and Aeromonas schubertii (2.5%) among the cultures isolated from pasteurized milk samples. Twenty-five percent of the strains could only be classified as Aeromonas spp. In white cheese samples, unclassified strains were the most frequent isolates (61.5%) followed by A. hydrophila (26.9%), A. caviae (7.6%) and Aeromonas sobria (3.8%). Only strains of A. hydrophila and A. sobria showed high rate of positive results when tested for the production of hemolysin, cytotoxin, and staphylolytic activity. Heat-stable enterotoxin and autoagglutination test did not correlate as virulence factors. The presence of Aeromonas species in refrigerated food samples suggests that this microorganism could be a potential foodborne pathogen, and dairy products may represent an important vehicle of its transmission.
PubMed: 31084036
DOI: 10.4315/0362-028X-56.1.62 -
Misidentification of unusual Aeromonas species as members of the genus Vibrio: a continuing problem.Journal of Clinical Microbiology Apr 1998Two unusual cases of Aeromonas infection are described, one associated with bacteremia (Aeromonas schubertii) and another in which the organism was recovered from an...
Two unusual cases of Aeromonas infection are described, one associated with bacteremia (Aeromonas schubertii) and another in which the organism was recovered from an infected gall bladder (Aeromonas veronii biotype veronii). These strains were initially identified as Vibrio damsela and Vibrio cholerae by the Vitek and API 20E systems, respectively. Use of appropriate screening tests and familiarity with the newer Aeromonas species could prevent initial misidentifications and potential public health consequences.
Topics: Aeromonas; Diagnostic Errors; Humans; Male; Middle Aged; Vibrio
PubMed: 9542946
DOI: 10.1128/JCM.36.4.1103-1104.1998