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Macêdo WV, Sakamoto IK, Azevedo EB, Damianovic MHRZ. The effect of cations (Na +, Mg 2+, and Ca 2+) on the activity and structure of nitrifying and denitrifying bacterial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 679:279-287. [PMID: 31082601 DOI: 10.1016/j.scitotenv.2019.04.397] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 06/09/2023]
Abstract
Wastewaters generated in regions with water scarcity usually have high alkalinity, hardness, and elevated osmotic pressure (OP). Those characteristics should be considered when using biological systems for wastewater treatment along with the salinity heterogeneity. The interaction of different salts in mixed electrolyte solutions may cause inhibition, antagonism, synergism, and stimulation effects on microbial communities. Little is known about those effects on microbial activity and community structure of nitrifying and denitrifying bacteria. In this work, factorial design was used to evaluate the effects of NaCl, MgCl2 and CaCl2 on nitrifying and denitrifying communities. Antagonistic relationships between all salts were observed and they had greater magnitude on the nitrifying community. Stimulus and synernism were more evident on the nitrifying and denitrifying experiments, respectively. For this reason, the highest nitrification and denitrification specific rates were 1.1 × 10-1 mgN-NH4+ gSSV-1 min-1 for condition 01 and 6.5 × 10-2 mgN-NO3- gSSV-1 min-1 for control condition, respectively. The toxicity of the salts followed the order of NaCl > MgCl2 > CaCl2 and the antagonism between MgCl2 and NaCl was the most significant. PCR/DGGE analyses showed that Mg2+ may be the element that expresses the least influence in the differentiation of microbial structure even though it significantly affects the activity of the autotrophic microorganisms. The same behavior was observed for Ca2+ on denitrifying microorganism. In addition, microbial diversity and richness was not negatively affected by different salinities. Genetic sequencing suggested that the genus Aeromonas, Alishewanella, Azospirillum, Pseudoalteromonas, and Thioalkalivibrio were outstanding on ammonium and nitrate removal under saline conditions. The specific toxicity of each salt and the interactions among them are the major effects on microbial activity in biological wastewater treatments rather than the osmotic pressure caused by the final salinity.
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Affiliation(s)
- Williane Vieira Macêdo
- Biological Processes Laboratory (LPB), University of São Paulo (USP), 1100 João Dagnone Avenue, 13563-120 São Carlos, SP, Brazil.
| | - Isabel K Sakamoto
- Biological Processes Laboratory (LPB), University of São Paulo (USP), 1100 João Dagnone Avenue, 13563-120 São Carlos, SP, Brazil
| | - Eduardo Bessa Azevedo
- Environmental Technology Development Laboratory (LTDAmb), University of São Paulo (USP), 400 Trab. São Carlense Avenue, 13563-120 São Carlos, SP, Brazil
| | - Marcia Helena R Z Damianovic
- Biological Processes Laboratory (LPB), University of São Paulo (USP), 1100 João Dagnone Avenue, 13563-120 São Carlos, SP, Brazil
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2
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Fengqing H, Song Y. Electroporation-mediated transformation of Aeromonas hydrophila. Plasmid 2005; 54:283-7. [PMID: 15967502 DOI: 10.1016/j.plasmid.2005.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2005] [Revised: 04/21/2005] [Accepted: 04/22/2005] [Indexed: 10/25/2022]
Abstract
A strain of Aeromonas hydrophila producing copolyesters of 3-hydroxybutyrate and 3-hydroxyhexanoate, abbreviated as PHBHHx, was successfully transformed by electroporation. The plasmid used was a broad host range plasmid pBBR1MCS. Electroporation conditions were varied systemically to develop an electroporation protocol. The optimal yield of transformant was approximately 4x10(2) CFU/microg DNA at 12.5 kV/cm and 1000 Omega, resulting in a time constant of approximately 5 ms. The A. hydrophila transformants expressed plasmid-encoded resistance to chloromphenicol. Plasmid DNA in the A. hydrophila transformant was stably maintained. This is the first report of transformation of bacteria A. hydrophila.
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Affiliation(s)
- Hu Fengqing
- Department of Life Science, Liaoning University, Shenyang 110036, China.
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3
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Prevalence of Aeromonas hydrophila in fish and prawns from the seafood market of Coimbatore, South India. Food Microbiol 2005. [DOI: 10.1016/j.fm.2004.01.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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YUCEL NIHAL, ÇITAK SUMRU. THE OCCURRENCE, HEMOLYTIC ACTIVITY AND ANTIBIOTIC SUSCEPTIBILITY OF MOTILE AEROMONAS SPP. ISOLATED FROM MEAT AND MILK SAMPLES IN TURKEY. J Food Saf 2003. [DOI: 10.1111/j.1745-4565.2003.tb00362.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Suñen E, Aristimuño C, Fernandez-Galian B. Activity of smoke wood condensates against Aeromonas hydrophila and Listeria monocytogenes in vacuum-packaged, cold-smoked rainbow trout stored at 4 °C. Food Res Int 2003. [DOI: 10.1016/s0963-9969(02)00115-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Chapter 19 Culture media for Aeromonas spp. and Plesiomonas shigelloides. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0079-6352(03)80022-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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7
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Sechi LA, Deriu A, Falchi MP, Fadda G, Zanetti S. Distribution of virulence genes in Aeromonas spp. isolated from Sardinian waters and from patients with diarrhoea. J Appl Microbiol 2002; 92:221-7. [PMID: 11849349 DOI: 10.1046/j.1365-2672.2002.01522.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To characterize 46 isolates of different Aeromonas spp. strains (26 Aeromonas hydrophila, 13 Aeromonas sobria and 7 Aeromonas salmonicida) isolated from coastal water and clinical sources in Sardinia, Italy. METHODS AND RESULTS The isolates were analysed for the production of the following virulence properties: slime, haemolysin, gelatinase and protease production, and adhesion to eucaryotic epithelial cells. The presence of known virulence genes: A. hydrophila cytolytic enterotoxin gene AHCYTOEN; type IV pilus gene Tap; Bundle forming pilus genes BfpA and BfpG were investigated using polymerase chain reaction (PCR). In addition the enterobacterial repetitive intergenic consensus sequences (ERIC)-PCR fingerprinting was used to further differentiate the strains. CONCLUSIONS This study confirms the presence of virulent Aeromonas strains in the Mediterranean sea. The study also found a greater prevalence of haemolysin, protease and gelatinase production, as well as a higher adhesion capacity, among strains isolated from patients with diarrhoea. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first time that Aeromonads have been isolated and characterized from Sardinian waters and from patients with diarrhoea in Sardinia. This study adds to our knowledge of the ecology of this micro-organism and may in the future help prevent infections both in fish and in humans.
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Affiliation(s)
- L A Sechi
- Dipartimento di Scienze Biomediche, Sezione di Microbiologia Sperimentale e Clinica, Università di Sassari, v.le S. Pietro 43/b, 07100 Sassari, Italy.
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8
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Birkenhauer JM, Oliver JD. Effects of refrigeration and alcohol on the load of Aeromonas hydrophila in oysters. J Food Prot 2002; 65:560-2. [PMID: 11899058 DOI: 10.4315/0362-028x-65.3.560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Members of the bacterial genus Aeromonas are widely distributed throughout the environment and are readily cultured from a variety of foods. One member of this genus, Aeromonas hydrophila, has been reputed to be a significant cause of gastrointestinal disease. In this study, we examined the effects of refrigeration and alcohol on the level of A. hydrophila in oysters. Specifically, vodka was examined because it is used by the food service industry in preparation of Oysters Romanoff. One set of oysters was shucked on receipt, whereas others were refrigerated intact for 7 days at 5 degrees C. The oysters were blended and the numbers of A. hydrophila present determined using starch ampicillin agar. Oysters were also shucked and placed on the half shell with 5 ml of vodka for 10 min. The oysters were then washed and presumptive A. hydrophila levels determined in both the washate and homogenate. On the day of purchase, the average number of presumptive A. hydrophila found was 7.6 x 10(4) CFU/g of oyster meat. After 7 days of refrigeration, the average number had increased to 3.2 x 10(5) CFU/g of oyster meat. In the oysters treated with vodka, the average number of A. hydrophila present internally was 9.9 x 10(4) with high numbers (10(3) to 10(4)) isolated from the oyster surface. From these data, it is clear that refrigeration and alcohol treatment are not sufficient to reduce loads of A. hydrophila in or on oysters.
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Affiliation(s)
- J M Birkenhauer
- Department of Biology, University of North Carolina at Charlotte, 28223, USA
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9
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Antibacterial activity of smoke wood condensates against Aeromonas hydrophila, Yersinia enterocolitica andListeria monocytogenes at low temperature. Food Microbiol 2001. [DOI: 10.1006/fmic.2001.0411] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Villari P, Crispino M, Montuori P, Stanzione S. Prevalence and molecular characterization of Aeromonas spp. in ready-to-eat foods in Italy. J Food Prot 2000; 63:1754-7. [PMID: 11131903 DOI: 10.4315/0362-028x-63.12.1754] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A survey was carried out in Italy to ascertain the prevalence of Aeromonas spp. in ready-to-eat foods (vegetables, cheeses, meat products, and ice creams) and the level of molecular heterogeneity of the isolates found by macrorestriction analysis of genomic DNA with pulsed-field gel electrophoresis (PFGE). In total, 46 (14.4%) of the 320 food samples examined were found positive for Aeromonas spp. The highest percentages of isolation were discovered in vegetables, particularly lettuce (45.0%), endive (40.0%), and rucola (20.0%). Ricotta was the only cheese type analyzed that showed a high frequency of isolation (45.0%). Among meat products, salami and raw ham (25.0% of samples positive) and, to a lesser extent, baloney (5.0%) were found positive for Aeromonas spp. Aeromonas hydrophila was the most common isolate from foods of animal origin, whereas Aeromonas caviae was the dominant species in vegetables. No motile aeromonads were found in ice cream samples. Aeromonas isolates showed a high level of genetic heterogeneity, because 24 PFGE patterns were identified among 27 A. hydrophila strains and 20 PFGE patterns were found in 23 A. caviae isolates. In conclusion, consumers of ready-to-eat foods in Italy are regularly exposed to many genetically distinct strains of A. hydrophila and A. caviae without evident signs of malaise, and therefore, few of these strains, if any, are likely to be pathogenic.
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Affiliation(s)
- P Villari
- Department of Health and Preventive Sciences, University Federico II, Naples, Italy.
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11
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Yeşim Özbaş Z, Lehner A, Wagner M. Development of a multiplex and semi-nested PCR assay for detection of Yersinia enterocolitica and Aeromonas hydrophila in raw milk. Food Microbiol 2000. [DOI: 10.1006/fmic.1999.0298] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Imziln B, Krovacek K, Baloda SB, Kühn I, Gonzalez-Rey C, Svenson SB. Characterisation of potential virulence markers in Aeromonas caviae isolated from polluted and unpolluted aquatic environments in Morocco. FEMS Microbiol Ecol 1998. [DOI: 10.1111/j.1574-6941.1998.tb00533.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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13
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Pin C, Morales P, Marín ML, Selgas MD, García ML, Casas C. Virulence factors-pathogenicity relationships for Aeromonas species from clinical and food isolates. Folia Microbiol (Praha) 1997; 42:385-9. [PMID: 9449784 DOI: 10.1007/bf02816954] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The presence of virulence factors in 96 Aeromonas strains isolated from food and clinical samples was studied. Neither cytotoxic activity and hydrophobicity, not the presence of pili or an extra surface layer made it possible to establish differences between food and clinical strains. Statistical studies showed that cytotoxin production was associated with a positive Voges-Proskauer reaction, inability to ferment arabinose and a positive lysine decarboxylation. Therefore, when comparing cytotoxic clinical and food strains with lysine decarboxylation phenotype, there was a significant difference (p < 0.05) between the two groups. The association of a cytotoxin production and lysine decarboxylation character should thus be considered as a possible virulence marker.
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Affiliation(s)
- C Pin
- Departamento de Nutrición y Bromatología III, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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14
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Hänninen ML, Oivanen P, Hirvelä-Koski V. Aeromonas species in fish, fish-eggs, shrimp and freshwater. Int J Food Microbiol 1997; 34:17-26. [PMID: 9029253 DOI: 10.1016/s0168-1605(96)01163-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Aeromonas spp. are common contaminants of fish and seafood. They also are ubiquitous in the water environment. Aeromonas spp. were identified in 27 (93%) of 29 fish, in 17 (100%) fish-egg, in two (16%) of 12 shrimp samples and in 23 (100%) freshwater samples. In total, 117 Aeromonas strains were isolated from 69 positive samples, several samples having had two or three Aeromonas species. Included in this were also 26 mesophilic Aeromonas strains isolated in association with the study on fish diseases. The distribution of the species into 13 known hybridization groups (HGs) were studied by phenotypic and molecular methods. Ribopattern analysis of SmaI digested DNA was used for the identification of HGs. The predominant HG in fish, fish-eggs and freshwater samples was A. hydrophila HG 3 because 63% (22/37), 28% (16/57) or 80% (16/20) of the strains, respectively, were in HG 3. A. hydrophila HG 2 was also common in fresh fish samples but was not identified in fish-egg samples. HG 7 was common in fish samples studied for fish diseases and in freshwater samples. Strains which were not allotted to any HGs were common (19 of 143 strains). A. hydrophila HG 1, A. caviae HG 4, A. veronii subspecies sobria or subspecies veronii HG 8/10 known to be associated with human diarrhea were uncommon in all samples. The three strains isolated from frozen shrimp during two suspected food-borne outbreaks were A. hydrophila HG 2 and HG 3.
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Affiliation(s)
- M L Hänninen
- University of Helsinki, Faculty of Veterinary Medicine, Finland
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15
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Ozbaş ZY, Vural H, Aytaç SA. Combined effect of gamma-irradiation and conventional cooking on Aeromonas hydrophila in meatball. ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND -FORSCHUNG 1996; 202:60-2. [PMID: 8717095 DOI: 10.1007/bf01229686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Irradiation combined with a conventional cooking procedure was applied to meatball and the effects on bacterial load and inoculated Aeromonas hydrophila were determined. Meatball samples were irradiated by using a 60Co source at the dose levels of 0, 0.30, 0.75, 1.50, 2.50 kGy and cold stored at 4 +/- 1 degrees C for 7 days. Bacterial load and the count of A. hydrophila decreased when the irradiation dose level increased. A minimum inhibition effect was found at the dose of 0.30 kGy. Irradiation in combination with a conventional cooking procedure was found to be more effective in reducing A. hydrophila and the bacterial load in meatball. This study indicated that a dose of 0.75 kGy was sufficient to destroy approximately 10(4) cfu/g of A. hydrophila in meatball.
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Affiliation(s)
- Z Y Ozbaş
- Department of Food Engineering, Hacettepe University, Ankara, Turkey
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16
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Stecchini M, Sarais I, Del Torre M, Fuochi P. Effect of electron irradiation and packaging atmosphere on the survival of aeromonas hydrophila in minced poultry meat. Radiat Phys Chem Oxf Engl 1993 1995. [DOI: 10.1016/0969-806x(95)00260-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Krovacek K, Dumontet S, Eriksson E, Baloda SB. Isolation, and virulence profiles, of Aeromonas hydrophila implicated in an outbreak of food poisoning in Sweden. Microbiol Immunol 1995; 39:655-61. [PMID: 8577278 DOI: 10.1111/j.1348-0421.1995.tb03253.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A case of food poisoning outbreak involving Aeromonas hydrophila is reported in this study. A group of 27 people consumed a typical Swedish food "landgång" which is a type of smörgåsbord containing shrimps with mayonnaise, liver paté, ham, sausage, and legume salad which was purchased from a food store. Twenty-two of the 27 persons became ill within 20-34 hr of consumption of the food and reported the symptoms ranging from severe acute diarrhea, abdominal pain, headache, fever and vomiting. One person also fainted. The symptoms lasted for a couple of days. Of the remaining 5 healthy persons who consumed the left-over food the next day, 2 became ill with similar symptoms. The bacteriological examination of left-over food samples resulted in the isolation of A. hydrophila from shrimps with mayonnaise, smoked sausage, liver paté and boiled ham. The total number of A. hydrophila in these foods were log 10(6) to log > 10(7) organisms per gram of food sample. A. hydrophila was however, not isolated from legume/mayonnaise salad samples. All the food samples tested showed low numbers of other expected food contaminating organisms such as coliforms at 37 C and 44 C, fecal streptococci, Staphylococcus aureus, fungi and yeast etc., while Bacillus cereus, Clostridium perfringens and Salmonella spp. were not detected in the food samples. Investigations of the virulence profiles of the A. hydrophila isolates showed their capacity to produce beta-hemolysin, cytotoxins, cytotonic toxins, enterotoxins, and adhesion to and invasion of human intestinal (Henle 407) cells in culture.
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Affiliation(s)
- K Krovacek
- Department of Veterinary Microbiology, Swedish University of Agricultural Sciences, Biomedical Center, Uppsala, Sweden
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18
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Pin C, Marín ML, Selgas D, García ML, Tormo J, Casas C. Differences in production of several extracellular virulence factors in clinical and food Aeromonas spp. strains. THE JOURNAL OF APPLIED BACTERIOLOGY 1995; 78:175-9. [PMID: 7698952 DOI: 10.1111/j.1365-2672.1995.tb02839.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Production of several extracellular virulence factors (lipase, protease and haemolysin) was compared in 15 Aeromonas spp. isolated from faeces of patients with Aeromonas-associated gastroenteritis and 81 strains isolated from food. Strains from food did not show differences in production of these factors when compared with strains isolated from faeces. However, if strains were considered in relation to autoagglutination (AA) character, the AA+ differed from AA- strains in lipase and protease production. Supernatant fluids of AA+ food and human strains showed 2.5-fold more protease production than that observed in AA- strains. These two characteristics of certain Aeromonas strains could be related with the more virulent capacity.
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Affiliation(s)
- C Pin
- Departamento de Nutrición y Bromatologia III, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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19
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Pin C, Marín ML, Selgas MD, García ML, Tormo J, Casas C. Virulence factors in clinical and food isolates of Aeromonas species. Folia Microbiol (Praha) 1994; 39:331-6. [PMID: 7729770 DOI: 10.1007/bf02814323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Virulence factors were compared in 15 Aeromonas spp. isolated from faeces of patients with Aeromonas-associated gastroenteritis and in 81 strains isolated from food. Strains from food did not show differences in the distribution of virulence factors when compared with strains isolated from faeces. However, 88.8% of Aeromonas strains isolated from food were capable of producing possible virulence factors. Characterization of 28 autoagglutinating (AA+) Aeromonas spp. indicated that the human strains differed from the food strains in hemagglutinating and hemolytic capacities. These results suggest that autoagglutination associated with hemagglutinating and hemolytic capacities in food strains may be a helpful indicator of potential pathogenicity.
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Affiliation(s)
- C Pin
- Departmento de Nutrición y Bromatología III, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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20
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Nguyen-the C, Carlin F. The microbiology of minimally processed fresh fruits and vegetables. Crit Rev Food Sci Nutr 1994; 34:371-401. [PMID: 7945895 DOI: 10.1080/10408399409527668] [Citation(s) in RCA: 597] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Minimally processed fresh (MPF) fruits and vegetables are good media for growth of microorganisms. They have been involved in outbreaks because of the consumption of products contaminated by pathogens. They are also sensitive to various spoilage microorganisms such as pectinolytic bacteria, saprophytic Gram-negative bacteria, lactic acid bacteria, and yeasts. Contamination of MPF fruits and vegetables occurs at every stage of the food chain, from cultivation to processing. Polluted environments during cultivation or poor hygienic conditions in processing increase the risk of contamination with foodborne pathogens. Although MPF fruits and vegetables may harbor psychrotrophic microorganisms such as fluorescent pseudomonads or Listeria monocytogenes, good control of refrigeration temperature limits growth of spoilage and pathogenic microorganisms. Modified atmospheres are often efficient to maintain or improve visual organoleptic quality of MPF fruits and vegetables, but their effects on microorganisms are inconsistent. Chemical disinfection can partially reduce the initial bacterial contamination; irradiation seems to be more efficient. The applications of legislations and quality assurance systems to control contamination, survival, and growth of foodborne pathogens in MPF fruits and vegetables are discussed.
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Affiliation(s)
- C Nguyen-the
- Institut National de la Recherche Agronomique, Station de Technologie des Produits Végétaux, Montfavet, France
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21
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Abstract
There is now evidence that some strains of Aeromonas species are enteropathogens. Such strains possess virulence properties, such as the ability to produce enterotoxins, cytotoxins, haemolysins and/or the ability to invade epithelial cells. Strains with these properties are common contaminants of drinking water and a wide range of foods. Contact or consumption of contaminated water, especially in summer, is a major risk factor in Aeromonas-associated gastroenteritis. Aeromonas-contaminated foods may also be vehicles of infection. Given the properties of strains that have been described in foods it has been suggested that food-borne illness could result not only from colonization and in vivo expression of virulence factors, but possibly also by intoxication following ingestion of foods that have been stored for a period of time, even under refrigeration. This paper reviews what is known about Aeromonas spp. in foods, their expression of virulence determinants, particularly at refrigeration temperatures, and the questions remaining to be answered to evaluate the risk they pose, so that an appropriate public health response can be determined.
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Affiliation(s)
- S M Kirov
- Department of Pathology, University of Tasmania Clinical School, Hobart, Australia
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Stecchini ML, Sarais I, Giomo A. Thermal Inactivation of
Aeromonas hydrophila
As Affected by Sodium Chloride and Ascorbic Acid. Appl Environ Microbiol 1993; 59:4166-70. [PMID: 16349116 PMCID: PMC195881 DOI: 10.1128/aem.59.12.4166-4170.1993] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The combined effects of sodium chloride (0, 1.0, 1.5, and 3.0%) and ascorbic acid (0, 1.0, and 2.0 mmol/liter) with mild heat (46°C) on the survival of
Aeromonas hydrophila
were evaluated. Because of the nonlinear nature of the survivor curves obtained, several equations yielding an
R
2
(coefficient of multiple determination) of ≅ 1 were tested. The equation that most closely fit the curvature of the observed data set was a hyperbolic function. Equation coefficients were combined to obtain a so-called death value. This value (46.67% explained variance) was calculated by extracting the larger eigenvalue and the relative eigenvector from the correlation matrix of the coefficients. the effects of the experimental factors on the death value were described by a quadratic response surface model. Results revealed that the death value was not influenced by the presence of ascorbic acid. However, increased mortality resulted from the interaction between sodium chloride and ascorbic acid.
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Affiliation(s)
- M L Stecchini
- Dipartimento di Scienze degli Alimenti, Universita degli Studi di Udine, Via Marangoni 97, 33100 Udine, Italy
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23
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Stecchini ML, Sarais I, Milani S. The effect of incubation temperature, sodium chloride and ascorbic acid on the growth kinetics of Aeromonas hydrophila. Lett Appl Microbiol 1993. [DOI: 10.1111/j.1472-765x.1993.tb01456.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jeppesen VF, Huss HH. Antagonistic activity of two strains of lactic acid bacteria against Listeria monocytogenes and Yersinia enterocolitica in a model fish product at 5 degrees C. Int J Food Microbiol 1993; 19:179-86. [PMID: 8217515 DOI: 10.1016/0168-1605(93)90075-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The antagonistic activity of lactic acid bacteria against one strain of Listeria monocytogenes, Scott A and one strain of Yersinia enterocolitica serotype O:3 was studied by using either a strain of a Leuconostoc spp. or a Lactobacillus plantarum strain. Each of the two potential pathogenic, psychrotrophic bacteria were inoculated with either of the two lactic acid bacteria in sterile shrimp extracts containing citric acid (pH 5.8 and 6.0) and in some experiments also 3% (w/v) NaCl. The samples were incubated at 5 degrees C. Antagonistic effect was obtained with both lactic acid bacteria against both pathogenic organisms, with the effect depending on inoculation levels of the pathogenic organism, the lactic acid bacteria strain and media composition.
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Affiliation(s)
- V F Jeppesen
- Technological Laboratory, Danish Ministry of Fisheries, Technical University, Lyngby
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25
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Walker SJ, Brooks J. Survey of the incidence of Aeromonas and Yersinia species in retail foods. Food Control 1993. [DOI: 10.1016/0956-7135(93)90125-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Krovacek K, Faris A, Baloda SB, Lindberg T, Peterz M, Mnsson I. Isolation and virulence profiles of Aeromonas spp. from different municipal drinking water supplies in Sweden. Food Microbiol 1992. [DOI: 10.1016/0740-0020(92)80049-a] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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27
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Schofield GM. Emerging food-borne pathogens and their significance in chilled foods. THE JOURNAL OF APPLIED BACTERIOLOGY 1992; 72:267-73. [PMID: 1517168 DOI: 10.1111/j.1365-2672.1992.tb01834.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- G M Schofield
- Unilever Research, Colworth Laboratory, Sharnbrook, Bedfordshire, UK
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28
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Krovacek K, Faris A, Baloda SB, Peterz M, Lindberg T, Mnsson I. Prevalence and characterization of Aeromonas spp. isolated from foods in Uppsala, Sweden. Food Microbiol 1992. [DOI: 10.1016/0740-0020(92)80059-d] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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29
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Stecchini M, Giavedoni P, Sarais I, Lerici C. Effect of Maillard reaction products on the growth of selected food-poisoning micro-organisms. Lett Appl Microbiol 1991. [DOI: 10.1111/j.1472-765x.1991.tb00579.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Abstract
The ability of many strains of Aeromonas hydrophila and A. sobria to produce several types of virulence factors has been documented. The presence of Aeromonas in drinking water, as well as in river and saline waters and on various finfish and shellfish taken from them, has caused some concern relative to the role this bacterium plays as a causative agent of human gastroenteritis. The fairly common occurrence of Aeromonas on red meats, poultry and fresh produce and its ability to grow at 4 degrees C gives rise to further concern over public health risks which may be associated with consumption of these foods. A brief overview of the behavior of Aeromonas species at refrigeration temperatures is presented.
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Affiliation(s)
- L R Beuchat
- Department of Food Science and Technology, University of Georgia, Griffin 30223-1797
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31
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Krovacek K, Faris A, Månsson I. Growth of and toxin production by Aeromonas hydrophila and Aeromonas sobria at low temperatures. Int J Food Microbiol 1991; 13:165-75. [PMID: 1888660 DOI: 10.1016/0168-1605(91)90058-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of different temperatures on the growth and toxin production of Aeromonas hydrophila and Aeromonas sobria were studied. The results showed that these Aeromonas species are not only able to grow at low temperatures (e.g. at 4 and 10 degrees C) but may also produce cytotoxin, hemolysin and enterotoxin under suitable growth conditions.
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Affiliation(s)
- K Krovacek
- Department of Veterinary Microbiology, College of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala
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32
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Kirov SM, Anderson MJ, McMeekin TA. A note on Aeromonas spp. from chickens as possible food-borne pathogens. THE JOURNAL OF APPLIED BACTERIOLOGY 1990; 68:327-34. [PMID: 2351618 DOI: 10.1111/j.1365-2672.1990.tb02882.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The possible role of Aeromonas spp. as potential food-borne psychrotrophic pathogens was investigated by examining organisms isolated from processed raw chicken for their biochemical characteristics, ability to produce exotoxins and to grow at chill temperatures. These strains, in particular A. sobria, with identical characteristics to human diarrhoea-associated aeromonads were readily found. Chicken, and human and environmental (water) strains characterized in a previous study, were investigated for their ability to grow at refrigeration temperatures (5 +/- 2 degrees C) and, for selected strains, the theoretical minimum temperature for growth (Tmin) was determined from the growth pattern in a temperature gradient incubator. All enterotoxigenic chicken strains tested were typical mesophiles, with an optimal growth temperature of approximately 37 degrees C and Tmin values approximately 4.5 degrees C. They were rapidly outgrown by a psychrotrophic Pseudomonas sp. typical of spoilage biota found on food. Enterotoxin was not produced below 15 degrees C by any of the toxigenic food strains tested. The Aeromonas strains isolated from chickens in this study seem unlikely therefore to be a significant health risk, provided the chickens are properly stored and cooked. This would appear to be substantiated by the lack of reports of food-associated outbreaks of illness from these sources.
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Affiliation(s)
- S M Kirov
- Department of Pathology, University of Tasmania Clinical School, Australia
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