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Divergent Nrf Family Proteins and MtrCAB Homologs Facilitate Extracellular Electron Transfer in Aeromonas hydrophila. Appl Environ Microbiol 2018; 84:AEM.02134-18. [PMID: 30266730 DOI: 10.1128/aem.02134-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/26/2018] [Indexed: 01/05/2023] Open
Abstract
Extracellular electron transfer (EET) is a strategy for respiration in which electrons generated from metabolism are moved outside the cell to a terminal electron acceptor, such as iron or manganese oxide. EET has primarily been studied in two model systems, Shewanella oneidensis and Geobacter sulfurreducens Metal reduction has also been reported in numerous microorganisms, including Aeromonas spp., which are ubiquitous Gammaproteobacteria found in aquatic ecosystems, with some species capable of pathogenesis in humans and fish. Genomic comparisons of Aeromonas spp. revealed a potential outer membrane conduit homologous to S. oneidensis MtrCAB. While the ability to respire metals and mineral oxides is not widespread in the genus Aeromonas, 90% of the sequenced Aeromonas hydrophila isolates contain MtrCAB homologs. A. hydrophila ATCC 7966 mutants lacking mtrA are unable to reduce metals. Expression of A. hydrophila mtrCAB in an S. oneidensis mutant lacking homologous components restored metal reduction. Although the outer membrane conduits for metal reduction were similar, homologs of the S. oneidensis inner membrane and periplasmic EET components CymA, FccA, and CctA were not found in A. hydrophila We characterized a cluster of genes predicted to encode components related to a formate-dependent nitrite reductase (NrfBCD), here named NetBCD (for Nrf-like electron transfer), and a predicted diheme periplasmic cytochrome, PdsA (periplasmic diheme shuttle). We present genetic evidence that proteins encoded by this cluster facilitate electron transfer from the cytoplasmic membrane across the periplasm to the MtrCAB conduit and function independently from an authentic NrfABCD system. A. hydrophila mutants lacking pdsA and netBCD were unable to reduce metals, while heterologous expression of these genes could restore metal reduction in an S. oneidensis mutant background. EET may therefore allow A. hydrophila and other species of Aeromonas to persist and thrive in iron- or manganese-rich oxygen-limited environments.IMPORTANCE Metal-reducing microorganisms are used for electricity production, bioremediation of toxic compounds, wastewater treatment, and production of valuable compounds. Despite numerous microorganisms being reported to reduce metals, the molecular mechanism has primarily been studied in two model systems, Shewanella oneidensis and Geobacter sulfurreducens We have characterized the mechanism of extracellular electron transfer in Aeromonas hydrophila, which uses the well-studied Shewanella system, MtrCAB, to move electrons across the outer membrane; however, most Aeromonas spp. appear to use a novel mechanism to transfer electrons from the inner membrane through the periplasm and to the outer membrane. The conserved use of MtrCAB in Shewanella spp. and Aeromonas spp. for metal reduction and conserved genomic architecture of metal reduction genes in Aeromonas spp. may serve as genomic markers for identifying metal-reducing microorganisms from genomic or transcriptomic sequencing. Understanding the variety of pathways used to reduce metals can allow for optimization and more efficient design of microorganisms used for practical applications.
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Romero A, Saraceni PR, Merino S, Figueras A, Tomás JM, Novoa B. The Animal Model Determines the Results of Aeromonas Virulence Factors. Front Microbiol 2016; 7:1574. [PMID: 27757107 PMCID: PMC5048442 DOI: 10.3389/fmicb.2016.01574] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/20/2016] [Indexed: 12/19/2022] Open
Abstract
The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of Aeromonas hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analyzed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1ΔvapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild-type. Variations between models were evidenced using the AH-1ΔrmlB, which lacks the O-antigen lipopolysaccharide (LPS), and the AH-1ΔwahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim) and the AH-1::motX (non-motile but producing flagella). They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study demonstrates that zebrafish larvae can be used as a host model to assess the virulence factors of A. hydrophila. This model revealed more differences in pathogenicity than the in vitro models and enabled the detection of slight variations in pathogenesis not observed using intraperitoneal injections of mice or fish.
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Affiliation(s)
- Alejandro Romero
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Paolo R Saraceni
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Susana Merino
- Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona Spain
| | - Antonio Figueras
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Juan M Tomás
- Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona Spain
| | - Beatriz Novoa
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
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Ghatak S, Blom J, Das S, Sanjukta R, Puro K, Mawlong M, Shakuntala I, Sen A, Goesmann A, Kumar A, Ngachan SV. Pan-genome analysis of Aeromonas hydrophila, Aeromonas veronii and Aeromonas caviae indicates phylogenomic diversity and greater pathogenic potential for Aeromonas hydrophila. Antonie van Leeuwenhoek 2016; 109:945-56. [PMID: 27075453 DOI: 10.1007/s10482-016-0693-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/30/2016] [Indexed: 11/26/2022]
Abstract
Aeromonas species are important pathogens of fishes and aquatic animals capable of infecting humans and other animals via food. Due to the paucity of pan-genomic studies on aeromonads, the present study was undertaken to analyse the pan-genome of three clinically important Aeromonas species (A. hydrophila, A. veronii, A. caviae). Results of pan-genome analysis revealed an open pan-genome for all three species with pan-genome sizes of 9181, 7214 and 6884 genes for A. hydrophila, A. veronii and A. caviae, respectively. Core-genome: pan-genome ratio (RCP) indicated greater genomic diversity for A. hydrophila and interestingly RCP emerged as an effective indicator to gauge genomic diversity which could possibly be extended to other organisms too. Phylogenomic network analysis highlighted the influence of homologous recombination and lateral gene transfer in the evolution of Aeromonas spp. Prediction of virulence factors indicated no significant difference among the three species though analysis of pathogenic potential and acquired antimicrobial resistance genes revealed greater hazards from A. hydrophila. In conclusion, the present study highlighted the usefulness of whole genome analyses to infer evolutionary cues for Aeromonas species which indicated considerable phylogenomic diversity for A. hydrophila and hitherto unknown genomic evidence for pathogenic potential of A. hydrophila compared to A. veronii and A. caviae.
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Affiliation(s)
- Sandeep Ghatak
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India.
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, 35392, Giessen, Germany
| | - Samir Das
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Rajkumari Sanjukta
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Kekungu Puro
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | | | - Ingudam Shakuntala
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Arnab Sen
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, 35392, Giessen, Germany
| | - Ashok Kumar
- Division of Veterinary Public Health, Indian Veterinary Research Institute, Izatnagar, 243122, India
| | - S V Ngachan
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
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Isolation of Aeromonas hydrophila in the respiratory tract of wild boar: pathologic implications. J Zoo Wildl Med 2014; 44:1090-3. [PMID: 24450076 DOI: 10.1638/2013-0009r2.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aeromonas hydrophila has been repeatedly reported as an animal pathogen. This study describes a case of a wild boar piglet in Spain with severe purulent pneumonia caused by A. hydrophila. To confirm the presence of A. hydrophila in the respiratory tract of wild boars from the same region, lung samples from 34 adult hunted animals and nasal samples from 12 live animals were collected and cultured in selective medium. Lung lesions were studied in hunted wild boars to determine the presence of A. hydrophila and to assess its role as a possible respiratory pathogen in wild boars. A. hydrophila was isolated in 10.87% of the animals studied (8.82% of the dead animals and 16% of the live animals). However, its presence in the lungs of adults could not be correlated with the lesions found. Thus, the role of A. hydrophila as a respiratory pathogen is likely to be influenced by other factors, such as age, immunologic status, or coinfection with other pathogens. As a zoonotic pathogen, the presence of A. hydrophila in wild boars may pose a potential risk to people who consume their flesh.
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Igbinosa IH, Igumbor EU, Aghdasi F, Tom M, Okoh AI. Emerging Aeromonas species infections and their significance in public health. ScientificWorldJournal 2012; 2012:625023. [PMID: 22701365 PMCID: PMC3373137 DOI: 10.1100/2012/625023] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 03/20/2012] [Indexed: 12/28/2022] Open
Abstract
Aeromonas species are ubiquitous bacteria in terrestrial and aquatic milieus. They are becoming renowned as enteric pathogens of serious public health concern as they acquire a number of virulence determinants that are linked with human diseases, such as gastroenteritis, soft-tissue, muscle infections, septicemia, and skin diseases. Proper sanitary procedures are essential in the prevention of the spread of Aeromonas infections. Oral fluid electrolyte substitution is employed in the prevention of dehydration, and broad-spectrum antibiotics are used in severe Aeromonas outbreaks. This review presents an overview of emerging Aeromonas infections and proposes the need for actions necessary for establishing adequate prevention measures against the infections.
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Affiliation(s)
- Isoken H. Igbinosa
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Ehimario U. Igumbor
- School of Public Health, University of the Western Cape, Bellville 7535, Cape Town, South Africa
| | - Farhad Aghdasi
- Risk and Vulnerability Assessment Centre, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Mvuyo Tom
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
| | - Anthony I. Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
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Singh BR, Gulati BR, Virmani N, Chauhan M. Outbreak of Abortions and Infertility in Thoroughbred Mares Associated with Waterborne Aeromonas hydrophila. Indian J Microbiol 2011; 51:212-6. [PMID: 22654167 PMCID: PMC3209884 DOI: 10.1007/s12088-011-0088-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 09/11/2009] [Indexed: 11/24/2022] Open
Abstract
At a thoroughbred equine breeding farm near Hissar (Haryana), three mares aborted in their seventh month of pregnancy. The vaginal swabs of all aborted mares, and stomach contents, heart blood, liver, spleen and placenta of aborted fetuses yielded pure culture of Aeromonas hydrophila. In addition, A. hydrophila was also isolated from the vaginal swabs of three repeat breeding mares and faecal sample of a diarrheic foal. The source of infection was possibly water supply as all the water samples collected from taps, mother tank and storage tank were found to be positive for A. hydrophila. The antibiogram of all the isolates was similar showing resistance to ampicillin, carbenicillin, gentamicin, kanamycin and amikacin but sensitive to chloramphenicol, ciprofloxacin, cefuroxime, ceftriaxone, cotrimoxazole, cotrimazine, nitrofurantoin, streptomycin and tetracycline. All the 20 sera samples collected from three aborted and three repeat breeding, and eight in-contact mares, a diarrheic foal, three cows and two male buffaloes maintained at the same farm contained antibodies against A. hydrophila with titres ranging from 80 to 640. The water supply was instantly chlorinated using 0.05% sodium hypochlorite for three consecutive days and all the culturally positive mares were treated with intravaginal administration of 1 g ciprofloxacin, while the foal was given nitrofurantoin for three days. After one month, A. hydrophila could not be isolated either from mares or from their environment and antibody titre in all the seropositive animals showed a declining trend. Later, all the aborted and repeat breeding mares were confirmed to be pregnant. Thus, the present study indicated that water-borne A. hydrophila might be associated with equine abortions and infertility, and diarrhea in newborn foals.
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Affiliation(s)
- B. R. Singh
- National Research Centre on Equines, Sirsa Road, Hissar, 125 001 Haryana
- Veterinary Microbiology, ICAR Research Complex for NEH Region, Nagaland Centre, Jharnapani, 797 106 Nagland India
| | - B. R. Gulati
- National Research Centre on Equines, Sirsa Road, Hissar, 125 001 Haryana
| | - Nitin Virmani
- National Research Centre on Equines, Sirsa Road, Hissar, 125 001 Haryana
| | - Mamta Chauhan
- National Research Centre on Equines, Sirsa Road, Hissar, 125 001 Haryana
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The occurrence and antibiotic resistance of motile Aeromonas in livestock. Trop Anim Health Prod 2008; 41:199-204. [PMID: 18481193 DOI: 10.1007/s11250-008-9175-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 04/24/2008] [Indexed: 10/22/2022]
Abstract
The present study was carried out to assess the prevalence of motile Aeromonas spp. in the faeces of clinically healthy sheep, cattle and horses and evaluate their susceptibility to some anti-microbial agents. Rectal swabs from 120 sheep, 85 cattle and 20 horses were examined for Aeromonas species using alkaline peptone water (pH 8.4) as the enrichment medium and Aeromonas Selective Agar containing 5 mg/l ampicillin as the isolation medium. Identification and antibiotic resistance of motile Aeromonas strains was performed using Gram Negative Enteric ID panel. Motile aeromonads were isolated from 12 (10%) sheep, 7 (8.2%) cattle and 1 (5%) horse. Of these 20 aeromonad isolates, 13 were A. caviae, 6 were A.sobria and 1 was A. hydrophila. Aeromonas species in the faeces of livestock might pose a public health problem for humans who are in direct contact with contaminated animals. However, further studies should be performed on aeromonads relating to their transmission between animals and humans.
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GUNSALAM JURINWOLMON, RADU SON, BENJAMIN PATRICKGUDA, SELAMAT JINAP, ROBIN TUNUNG. EVIDENCE OF CROSS-CONTAMINATION OF AEROMONAS HYDROPHILA BY FINGERPRINTING: SIGNIFICANCE FOR FOOD SAFETY. J Food Saf 2006. [DOI: 10.1111/j.1745-4565.2006.00050.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Seshadri R, Joseph SW, Chopra AK, Sha J, Shaw J, Graf J, Haft D, Wu M, Ren Q, Rosovitz MJ, Madupu R, Tallon L, Kim M, Jin S, Vuong H, Stine OC, Ali A, Horneman AJ, Heidelberg JF. Genome sequence of Aeromonas hydrophila ATCC 7966T: jack of all trades. J Bacteriol 2006; 188:8272-82. [PMID: 16980456 PMCID: PMC1698176 DOI: 10.1128/jb.00621-06] [Citation(s) in RCA: 258] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The complete genome of Aeromonas hydrophila ATCC 7966(T) was sequenced. Aeromonas, a ubiquitous waterborne bacterium, has been placed by the Environmental Protection Agency on the Contaminant Candidate List because of its potential to cause human disease. The 4.7-Mb genome of this emerging pathogen shows a physiologically adroit organism with broad metabolic capabilities and considerable virulence potential. A large array of virulence genes, including some identified in clinical isolates of Aeromonas spp. or Vibrio spp., may confer upon this organism the ability to infect a wide range of hosts. However, two recognized virulence markers, a type III secretion system and a lateral flagellum, that are reported in other A. hydrophila strains are not identified in the sequenced isolate, ATCC 7966(T). Given the ubiquity and free-living lifestyle of this organism, there is relatively little evidence of fluidity in terms of mobile elements in the genome of this particular strain. Notable aspects of the metabolic repertoire of A. hydrophila include dissimilatory sulfate reduction and resistance mechanisms (such as thiopurine reductase, arsenate reductase, and phosphonate degradation enzymes) against toxic compounds encountered in polluted waters. These enzymes may have bioremediative as well as industrial potential. Thus, the A. hydrophila genome sequence provides valuable insights into its ability to flourish in both aquatic and host environments.
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Affiliation(s)
- Rekha Seshadri
- The Institute for Genomic Research, Division of J. Craig Venter Institute, Rockville, MD 20850,USA.
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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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Rossi Jr O, Amaral L, Nader Filho A. Bactérias do gênero Aeromonas em água de matadouro bovino. ARQ BRAS MED VET ZOO 2000. [DOI: 10.1590/s0102-09352000000500023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Verificou-se a ocorrência de bactérias do gênero Aeromonas em amostras de água (abastecimento/residuária) obtidas em matadouro bovino. Analisaram-se a água utilizada nas dependências internas, a água dos currais, utilizada na dessedentação, pré-higienização e tranqüilização dos animais e a água residuária da lavagem das carcaças. Das 30 amostras representativas de cada tipo, bactérias do gênero Aeromonas foram isoladas em 10 (33,3%) amostras da água dos currais e em 10 (33,3%) amostras da água residuária da lavagem de carcaças. Nenhuma das amostras da água tratada de abastecimento das instalações revelou-se positiva no isolamento. As espécies isoladas foram Aeromonas hydrophila em duas (2,2%) e Aeromonas caviae em 19 (21,1%) amostras. Uma cepa considerada atípica foi isolada da água dos currais. Os resultados evidenciaram que a água dos currais pode ser uma importante fonte de contaminação, principalmente para a pele, e através dela as Aeromonas sp. podem chegar à sala de matança.
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Hathcock TL, Schumacher J, Wright JC, Stringfellow J. The prevalence of Aeromonas species in feces of horses with diarrhea. J Vet Intern Med 1999. [PMID: 10449228 PMCID: PMC7166617 DOI: 10.1111/j.1939-1676.1999.tb02194.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Feces collected from 40 horses with diarrhea and 34 horses without diarrhea were examined to determine if an association existed between isolation of Aeromonas spp. and diarrhea. Samples were also examined for Salmonella spp., and identification of viruses and parasite ova. Neither Salmonella spp. nor Aeromonas spp. were isolated from the feces of 34 control horses. Aeromonas spp. were isolated from feces of 22 of 40 (55%) horses with diarrhea. Salmonella spp. were isolated from feces of 8 (20%) horses, and of these, 5 (12.5%) were also positive for Aeromonas spp. Twenty-nine isolates of Aeromonas spp. were recovered from the feces of 22 diarrheic horses. Of these isolates, more than 80% were susceptible on in vitro testing to amikacin, ceftiofur, chloramphenicol, and gentamicin. All isolates were susceptible to enrofloxacin. Diarrheic horses positive for Aeromonas were significantly (P = .04) older than diarrheic horses negative for Aeromonas spp. A significantly greater number of fecal samples were positive for Aeromonas spp. during March through August than samples examined in other months (P = .014). Results of this study indicate that Aeromonas spp. should be considered as a cause of diarrhea in horses.
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Affiliation(s)
- T L Hathcock
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
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Hathcock TL, Schumacher J, Wright JC, Stringfellow J. The prevalence of Aeromonas species in feces of horses with diarrhea. J Vet Intern Med 1999; 13:357-60. [PMID: 10449228 PMCID: PMC7166617 DOI: 10.1892/0891-6640(1999)013<0357:tposif>2.3.co;2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/1998] [Revised: 12/18/1998] [Accepted: 01/12/1999] [Indexed: 11/17/2022] Open
Abstract
Feces collected from 40 horses with diarrhea and 34 horses without diarrhea were examined to determine if an association existed between isolation of Aeromonas spp. and diarrhea. Samples were also examined for Salmonella spp., and identification of viruses and parasite ova. Neither Salmonella spp. nor Aeromonas spp. were isolated from the feces of 34 control horses. Aeromonas spp. were isolated from feces of 22 of 40 (55%) horses with diarrhea. Salmonella spp. were isolated from feces of 8 (20%) horses, and of these, 5 (12.5%) were also positive for Aeromonas spp. Twenty-nine isolates of Aeromonas spp. were recovered from the feces of 22 diarrheic horses. Of these isolates, more than 80% were susceptible on in vitro testing to amikacin, ceftiofur, chloramphenicol, and gentamicin. All isolates were susceptible to enrofloxacin. Diarrheic horses positive for Aeromonas were significantly (P = .04) older than diarrheic horses negative for Aeromonas spp. A significantly greater number of fecal samples were positive for Aeromonas spp. during March through August than samples examined in other months (P = .014). Results of this study indicate that Aeromonas spp. should be considered as a cause of diarrhea in horses.
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Affiliation(s)
- T L Hathcock
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
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Ghenghesh KS, Abeid SS, Jaber MM, Ben-Taher SA. Isolation and haemolytic activity of Aeromonas species from domestic dogs and cats. Comp Immunol Microbiol Infect Dis 1999; 22:175-9. [PMID: 10391504 DOI: 10.1016/s0147-9571(98)00134-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Rectal swabs from 120 domestic dogs and 15 domestic cats were examined for Aeromonas species using alkaline peptone water (pH 8.6) as the enrichment medium and blood agar containing 15 mg/l ampicillin as the plating medium. Aeromonads were isolated from 13 (10.8%) dogs and from 1 (6.7%) cat. Of the 14 aeromonads isolated in the present study only 9 were available for speciation and testing in the haemolysin assay. Of these 5 were A. sobria (including one from a cat), 2 were A. hydrophila and 2 were A. caviae. Six were positive in the haemolysin assay; 4 A. sobria (one from a cat) and 2 A. hydrophila. The presence of haemolysin producing-Aeromonas species in the faeces of domestic dogs and cats may pose a public health problem for humans who come into contact with such animals.
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Affiliation(s)
- K S Ghenghesh
- Department of Medical Microbiology, Faculty of Medicine, Alfateh University of Medical Sciences, Tripoli, Libyan Arab Jamahiriya
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Buncic S, Panin J. Presence of Aeromonas hydrophila in slaughtered animals. Int J Food Microbiol 1994; 23:221-5. [PMID: 7848784 DOI: 10.1016/0168-1605(94)90055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The fate of Aeromonas hydrophila after a bacteriaemia in four healthy pigs intravenously inoculated with 10(9) and 10(15) cells of the bacterium was investigated. In two pigs slaughtered 30 min after inoculation the bacteria were found in blood (8 x 10(2)/ml and 4.2 x 10(2)/ml), meat and fatty tissues (1-10/g), but not in liver, spleen and superficial inguinal lymph nodes. A. hydrophila was not found in blood, meat, fatty tissue, liver, spleen, kidneys and superficial inguinal lymph nodes of other two pigs slaughtered 5.5 h postinoculation, with exception of one superficial inguinal lymph node of one pig.
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Affiliation(s)
- S Buncic
- Meat Industry Research Institute, Hamilton, New Zealand
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Gray SJ, Stickler DJ, Bryant TN. The incidence of virulence factors in mesophilic Aeromonas species isolated from farm animals and their environment. Epidemiol Infect 1990; 105:277-94. [PMID: 2209733 PMCID: PMC2271891 DOI: 10.1017/s0950268800047889] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sixty-one isolates of Aeromonas spp. from the faeces of pigs, cows and a variety of associated environmental sources were examined for the characteristics that are reputed to have roles in pathogenicity. Most isolates of Aeromonas hydrophila were cytotoxic (96.4%) and were capable of producing cell elongation factor (75%) and haemagglutinins (67.9%). In contrast few of the Aeromonas caviae isolates produced these three markers (13.6%, 27.3% and 36.4% respectively). In general, Aeromonas sobria occupied an intermediate position (36.4%, 27.3% and 54.5%), but they did produce the highest mean invasion index for HEp-2 cells. Statistical analysis revealed significant associations between the carriage of these factors and it was clear that many isolates of aeromonads from water and animals possessed the full battery of putative virulence factors.
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Affiliation(s)
- S J Gray
- Public Health Laboratory Service, University Hospital of Wales, Heath Park, Cardiff
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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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Gray SJ, Stickler DJ. Some observations on the faecal carriage of mesophilic Aeromonas species in cows and pigs. Epidemiol Infect 1989; 103:523-37. [PMID: 2606161 PMCID: PMC2249526 DOI: 10.1017/s0950268800030922] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Replicate faecal samples from healthy individual pigs and cows were examined for the presence of Aeromonas sp. over a 12-month period. Aeromonads were found to be minor components of the faecal flora, only 8.8% of 520 samples from pigs and 4.6% of 481 samples from cows proving positive. Isolation rates in both groups of animals were seasonal. A hydrophila (62% of the isolates) was the predominant species in cows, followed by A. caviae (32%) and A. sobria (15%). This pattern was also recorded in the natural waters that the animals drank from during the period when the faecal carriage rate was at its highest. In pigs, A. caviae (59%) was more common than A. hydrophila (41%). A. sobria was not found in any of the pig-associated samples. It seems that cattle acquire their faecal aeromonads from drinking water. The source of the organisms in pigs is less clear.
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Affiliation(s)
- S J Gray
- Public Health Laboratory Service, University Hospital of Wales, Cardiff
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Abstract
From a total of 563 samples of various foodstuffs purchased from retail outlets in the Reading area 287 were found to contain mesophilic Aeromonas spp. The types of sample which were most frequently contaminated were poultry (79.3%) and offal (84.3%). Of three media compared for their efficiency in recovering Aeromonas spp. after enrichment in alkaline peptone water, Difco Aeromonas was the most efficient. Cytotoxin was produced by approximately 50% of the A. hydrophila and A. sobria strains but by none of A. caviae strains. It is concluded that both raw and cooked foods are potential sources for infecting human beings with Aeromonas spp.
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Abstract
Although the first Aeromonas strain was described by Zimmermann as early as in 1890, it took 60 years until Caselitz established human pathogenicity of strains then called "Vibrio jamaicensis". Since then, and especially in the last 10 years, there have been increasing numbers of reports on different infections caused by members of the genus Aeromonas. These include sepsis; meningitis; cellulitis; necrotizing fasciitis; ecthyma gangrenosum; pneumonia; peritonitis; conjunctivitis; corneal ulcer; endophthalmitis; osteomyelitis; suppurative arthritis; myositis; subphrenic abscess; liver abscess; cholecystitis and/or ascending cholangitis; urinary tract infection; endocarditis; ear, nose, and throat infections; balanitis; etc. The role of Aeromonas in gastrointestinal disease is very controversial. Increasing epidemiological data suggest that these organisms play a major role in enteric infections, but so far enteropathogenicity has not been demonstrable in experiments where volunteers were given high numbers of Aeromonas possessing different virulence factors. Virulence factors include hemolysin(s), enterotoxin(s), hemagglutinins, invasivity, and others; but these are not found more frequently in strains isolated from patients with diarrhea than from healthy controls. Whether there is a correlation between species and disease remains to be elucidated and requires more information about the taxonomy of this genus.
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Affiliation(s)
- M Altwegg
- Department of Medical Microbiology, University of Zurich, Switzerland
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Lallier R, Higgins R. Biochemical and toxigenic characteristics of Aeromonas spp. isolated from diseased mammals, moribund and healthy fish. Vet Microbiol 1988; 18:63-71. [PMID: 3188376 DOI: 10.1016/0378-1135(88)90116-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In this study we describe biochemical, toxigenic and surface characteristics of 33 motile Aeromonas isolated from diseased mammals, 3 from moribund marine mammals, 24 from healthy fish and 4 from moribund fish. Aeromonas hydrophila, A. caviae and A. sobria were isolated from both mammals and fish but at a different incidence. Aeromonas hydrophila was the predominant species isolated from clinical specimens; it was isolated from pneumonia, wound infections, septicemia and abortion in horses, cattle and pigs. Aeromonas sobria was isolated from one mammal and 11 healthy fish. Aeromonas caviae was isolated in 2 cases from healthy fish and in 9 cases from diseased mammals. Variations in some biochemical tests including sorbitol, amylase and citrate, were observed between isolates from different sources. However, these differences did not allow the differentiation of isolates from diseased mammals and healthy fish. The majority of A. hydrophila isolates produced different extracellular products; A. sobria isolates produced less exotoxin. With A. caviae isolates no hemolysin, protease, enterotoxin or elastase were detected. There was no quantitative difference in hemolysin, protease, enterotoxin or elastase production between isolates from mammals and fish. It is suggested that A. hydrophila could be a potential pathogen for domestic animals, and fish may represent a potential reservoir of infection.
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Affiliation(s)
- R Lallier
- Groupe de Recherche en Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Que, Canada
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Abstract
The number of reports on the isolation of Aeromonas from patients with diarrhoeal disease is now large and suggests an etiological role of the bacterium. It is well established that strains of Aeromonas produce an enterotoxin. This enterotoxin is cytotonic, i.e. it does not damage the membrane, and it does not cross-react immunologically with cholera toxin and Escherichia coli heat-labile (LT) toxin. Most enterotoxigenic strains also produce a cytotoxic protein (hemolysin), the role of which is probably limited in diarrhoea but potentially toxic in humans in other kinds of infections. Strains of Plesiomonas shigelloides also seem to be able to cause diarrhoea in some cases. The pathogenesis of Plesiomonas-induced diarrhoea remains to be elucidated, but a heat-stable enterotoxin may be involved.
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