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Stentz R, Cheema J, Philo M, Carding SR. A Possible Aquatic Origin of the Thiaminase TenA of the Human Gut Symbiont Bacteroides thetaiotaomicron. J Mol Evol 2023; 91:482-491. [PMID: 37022443 PMCID: PMC10277260 DOI: 10.1007/s00239-023-10101-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 02/14/2023] [Indexed: 04/07/2023]
Abstract
TenA thiamin-degrading enzymes are commonly found in prokaryotes, plants, fungi and algae and are involved in the thiamin salvage pathway. The gut symbiont Bacteroides thetaiotaomicron (Bt) produces a TenA protein (BtTenA) which is packaged into its extracellular vesicles. An alignment of BtTenA protein sequence with proteins from different databases using the basic local alignment search tool (BLAST) and the generation of a phylogenetic tree revealed that BtTenA is related to TenA-like proteins not only found in a small number of intestinal bacterial species but also in some aquatic bacteria, aquatic invertebrates, and freshwater fish. This is, to our knowledge, the first report describing the presence of TenA-encoding genes in the genome of members of the animal kingdom. By searching metagenomic databases of diverse host-associated microbial communities, we found that BtTenA homologues were mostly represented in biofilms present on the surface of macroalgae found in Australian coral reefs. We also confirmed the ability of a recombinant BtTenA to degrade thiamin. Our study shows that BttenA-like genes which encode a novel sub-class of TenA proteins are sparingly distributed across two kingdoms of life, a feature of accessory genes known for their ability to spread between species through horizontal gene transfer.
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Affiliation(s)
- Régis Stentz
- Quadram Institute Bioscience, Gut Microbes and Health Research Programme, Norwich, UK.
| | - Jitender Cheema
- Computational and Systems Biology, John Innes Centre, Norwich, UK
| | - Mark Philo
- Core Science Resources, Quadram Institute Bioscience, Norwich, UK
| | - Simon R Carding
- Quadram Institute Bioscience, Gut Microbes and Health Research Programme, Norwich, UK
- Norwich Medical School, University East Anglia, Norwich, UK
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Schwartz K, Borowiak M, Strauch E, Deneke C, Richter M. Complete Genome Sequence of an Aeromonas rivuli Strain Isolated from Ready-to-Eat Food. Microbiol Resour Announc 2022; 11:e0113021. [PMID: 35442062 DOI: 10.1128/mra.01130-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Aeromonads can be associated with diseases in animals and humans. Knowledge regarding Aeromonas rivuli, a species recently discovered in creek water in Germany, is still fragmentary. Here, we announce the complete genome sequence of Aeromonas rivuli strain 20-VB00005, which was recovered from ready-to-eat food.
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Du X, Wang M, Zhou H, Li Z, Xu J, Li Z, Kan B, Chen D, Wang X, Jin Y, Ren Y, Ma Y, Liu J, Luan Y, Cui Z, Lu X. Comparison of the Multiple Platforms to Identify Various Aeromonas Species. Front Microbiol 2021; 11:625961. [PMID: 33537023 PMCID: PMC7848130 DOI: 10.3389/fmicb.2020.625961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/18/2020] [Indexed: 12/02/2022] Open
Abstract
We compared several identification methods for Aeromonas genus members, including traditional biochemical testing, multiplex-PCR amplification, mass spectrometry identification, whole-genome sequencing, multilocus phylogenetic analysis (MLPA), and rpoD, gyrA, and rpoD-gyrA gene sequencing. Isolates (n = 62) belonging to the Aeromonas genus, which were came from the bacterial bank in the laboratory, were used to assess the identification accuracy of the different methods. Whole-genome sequencing showed that the Aeromonas spp. isolates comprised A. caviae (n = 21), A. veronii (n = 18), A. dhakensis (n = 8), A. hydrophila (n = 7), A. jandaei (n = 5), A. enteropelogenes (n = 2), and A. media (n = 1). Using the whole-genome sequencing results as the standard, the consistency of the other methods was compared with them. The results were 46.77% (29/62) for biochemical identification, 83.87% (52/62) for mass spectrometric identification, 67.74% (42/62) for multiplex-PCR, 100% (62/62) for MLPA typing, 72.58% for gyrA, and 59.68% for rpoD and gyrA-rpoD. MLPA was the most consistent, followed by mass spectrometry. Therefore, in the public health laboratory, both MLPA and whole-genome sequencing methods can be used to identify various Aeromonas species. However, rapid and relatively accurate mass spectrometry is recommended for clinical lab.
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Affiliation(s)
- Xiaoli Du
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Mengyu Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,School of Public Health, Nanchang University, Nanchang, Jiangxi, China.,Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, China
| | - Haijian Zhou
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhenpeng Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jialiang Xu
- School of Light Industry, Beijing Technology and Business University, Beijing, China
| | - Zhe Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Biao Kan
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Daoli Chen
- Department of Microbiology Laboratory, Maanshan Center for Disease Control and Prevention of Anhui Province, Maanshan, China
| | - Xiaoli Wang
- Shijiazhuang Center for Disease Control and Prevention, Shijiazhuang, China
| | - Yujuan Jin
- Longgang Center for Disease Control and Prevention, Shenzhen, China
| | - Yan Ren
- LongHua District Center for Disease Control and Prevention, Shenzhen, China
| | - Yanping Ma
- Nanshan Center for Disease Control and Prevention, Shenzhen, China
| | - Jiuyin Liu
- Liaocheng Center for Disease Control and Prevention, Liaocheng, China
| | - Yang Luan
- Xi'an Center for Disease Control and Prevention, Xi'an, China
| | - Zhigang Cui
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xin Lu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Fernández-Bravo A, Figueras MJ. An Update on the Genus Aeromonas: Taxonomy, Epidemiology, and Pathogenicity. Microorganisms 2020; 8:microorganisms8010129. [PMID: 31963469 PMCID: PMC7022790 DOI: 10.3390/microorganisms8010129] [Citation(s) in RCA: 228] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 02/07/2023] Open
Abstract
The genus Aeromonas belongs to the Aeromonadaceae family and comprises a group of Gram-negative bacteria widely distributed in aquatic environments, with some species able to cause disease in humans, fish, and other aquatic animals. However, bacteria of this genus are isolated from many other habitats, environments, and food products. The taxonomy of this genus is complex when phenotypic identification methods are used because such methods might not correctly identify all the species. On the other hand, molecular methods have proven very reliable, such as using the sequences of concatenated housekeeping genes like gyrB and rpoD or comparing the genomes with the type strains using a genomic index, such as the average nucleotide identity (ANI) or in silico DNA–DNA hybridization (isDDH). So far, 36 species have been described in the genus Aeromonas of which at least 19 are considered emerging pathogens to humans, causing a broad spectrum of infections. Having said that, when classifying 1852 strains that have been reported in various recent clinical cases, 95.4% were identified as only four species: Aeromonas caviae (37.26%), Aeromonas dhakensis (23.49%), Aeromonas veronii (21.54%), and Aeromonas hydrophila (13.07%). Since aeromonads were first associated with human disease, gastroenteritis, bacteremia, and wound infections have dominated. The literature shows that the pathogenic potential of Aeromonas is considered multifactorial and the presence of several virulence factors allows these bacteria to adhere, invade, and destroy the host cells, overcoming the immune host response. Based on current information about the ecology, epidemiology, and pathogenicity of the genus Aeromonas, we should assume that the infections these bacteria produce will remain a great health problem in the future. The ubiquitous distribution of these bacteria and the increasing elderly population, to whom these bacteria are an opportunistic pathogen, will facilitate this problem. In addition, using data from outbreak studies, it has been recognized that in cases of diarrhea, the infective dose of Aeromonas is relatively low. These poorly known bacteria should therefore be considered similarly as enteropathogens like Salmonella and Campylobacter.
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Hossain S, De Silva BCJ, Dahanayake PS, De Zoysa M, Heo GJ. Phylogenetic characteristics, virulence properties and antibiogram profile of motile Aeromonas spp. isolated from ornamental guppy (Poecilia reticulata). Arch Microbiol 2020; 202:501-9. [PMID: 31707424 DOI: 10.1007/s00203-019-01762-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/28/2019] [Accepted: 10/31/2019] [Indexed: 02/08/2023]
Abstract
Aeromonas spp. are opportunistic pathogenic bacteria related to an assembly of infectious diseases in ornamental fish. In the present study, virulence properties and antibiotic susceptibility of 52 guppy-borne Aeromonas spp. were investigated. The isolates were identified as A. veronii (n = 34), A. dhakensis (n = 10), A. hydrophila (n = 3), A. caviae (n = 3) and A. enteropelogenes (n = 2) by gyrB gene sequencing. The gyrB sequence deviation within and among the species ranged from 0 to 2.6% and 2.7-9.2%. Each species formed a distinct group in the unrooted neighbor-joining phylogenetic tree. The phenotypic virulence factors such as β-hemolysis, slime, caseinase, DNase, gelatinase and lipase production were observed in 28 (53.9%), 33 (63.5%), 28 (53.9%), 42 (80.8%), 37 (71.2%) and 42 (80.8%) isolates, respectively. The virulence genes were detected by PCR assay in the following proportions- act (84.6%), hly (80.8%), aer (73.1%), lip (73.1%), gcaT (73.1%), ascV (53.8%), ahyB (53.8%) fla (51.9%), alt (48.1%), ast (36.5%) and ser (34.6%), respectively. The amoxicillin, ampicillin, imipenem, nalidixic acid, oxytetracycline and rifampicin were resistant to more than 70.0% of the isolates in antibiotic susceptibility test. Our study suggests that the ornamental guppy can be a potential reservoir of virulent and multi-drug resistant Aeromonas spp.
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Bello-López JM, Cabrero-Martínez OA, Ibáñez-Cervantes G, Hernández-Cortez C, Pelcastre-Rodríguez LI, Gonzalez-Avila LU, Castro-Escarpulli G. Horizontal Gene Transfer and Its Association with Antibiotic Resistance in the Genus Aeromonas spp. Microorganisms 2019; 7:E363. [PMID: 31540466 DOI: 10.3390/microorganisms7090363] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 12/24/2022] Open
Abstract
The evolution of multidrug resistant bacteria to the most diverse antimicrobials known so far pose a serious problem to global public health. Currently, microorganisms that develop resistant phenotypes to multiple drugs are associated with high morbidity and mortality. This resistance is encoded by a group of genes termed ‘bacterial resistome’, divided in intrinsic and extrinsic resistome. The first one refers to the resistance displayed on an organism without previous exposure to an antibiotic not involving horizontal genetic transfer, and it can be acquired via mutations. The latter, on the contrary, is acquired exclusively via horizontal genetic transfer involving mobile genetic elements that constitute the ‘bacterial mobilome’. This transfer is mediated by three different mechanisms: transduction, transformation, and conjugation. Recently, a problem of public health due to implications in the emergence of multi-drug resistance in Aeromonas spp. strains in water environments has been described. This is derived from the genetic material transfer via conjugation events. This is important, since bacteria that have acquired antibiotic resistance in natural environments can cause infections derived from their ingestion or direct contact with open wounds or mucosal tissue, which in turn, by their resistant nature, makes their eradication complex. Implications of the emergence of resistance in Aeromonas spp. by horizontal gene transfer on public health are discussed.
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Abstract
Aeromonads have been isolated from varied environmental sources such as polluted and drinking water, as well as from tissues and body fluids of cold and warm-blooded animals. A phenotypically and genotypically heterogenous bacteria, aeromonads can be successfully identified by ribotyping and/or by analysing gyrB gene sequence, apart from classical biochemical characterization. Aeromonads are known to cause scepticemia in aquatic organisms, gastroenteritis and extraintestinal diseases such as scepticemia, skin, eye, wound and respiratory tract infections in humans. Several virulence and antibiotic resistance genes have been identified and isolated from this group, which if present in their mobile genetic elements, may be horizontally transferred to other naive environmental bacteria posing threat to the society. The extensive and indiscriminate use of antibiotics has given rise to many resistant varieties of bacteria. Multidrug resistance genes, such as NDM1, have been identified in this group of bacteria which is of serious health concern. Therefore, it is important to understand how antibiotic resistance develops and spreads in order to undertake preventive measures. It is also necessary to search and map putative virulence genes of Aeromonas for fighting the diseases caused by them. This review encompasses current knowledge of bacteriological, environmental, clinical and virulence aspects of the Aeromonas group and related diseases in humans and other animals of human concern.
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Affiliation(s)
- Uttara Dey Bhowmick
- Cell and Molecular Biology Laboratory, Department of Zoology, University of North Bengal,Raja Rammohunpur, Siliguri, District Darjeeling, West Bengal,India
| | - Soumen Bhattacharjee
- Cell and Molecular Biology Laboratory, Department of Zoology, University of North Bengal,Raja Rammohunpur, Siliguri, District Darjeeling, West Bengal,India
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Hoel S, Vadstein O, Jakobsen AN. The Significance of Mesophilic Aeromonas spp. in Minimally Processed Ready-to-Eat Seafood. Microorganisms 2019; 7:E91. [PMID: 30909614 PMCID: PMC6463141 DOI: 10.3390/microorganisms7030091] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/14/2019] [Accepted: 03/15/2019] [Indexed: 02/06/2023] Open
Abstract
Minimally processed and ready-to-eat (RTE) seafood products are gaining popularity because of their availability in retail stores and the consumers' perception of convenience. Products that are subjected to mild processing and products that do not require additional heating prior to consumption are eaten by an increasing proportion of the population, including people that are more susceptible to foodborne disease. Worldwide, seafood is an important source of foodborne outbreaks, but the exact burden is not known. The increased interest in seafood products for raw consumption introduces new food safety issues that must be addressed by all actors in the food chain. Bacteria belonging to genus Aeromonas are ubiquitous in marine environments, and Aeromonas spp. has held the title "emerging foodborne pathogen" for more than a decade. Given its high prevalence in seafood and in vegetables included in many RTE seafood meals, the significance of Aeromonas as a potential foodborne pathogen and a food spoilage organism increases. Some Aeromonas spp. can grow relatively uninhibited in food during refrigeration under a broad range of pH and NaCl concentrations, and in various packaging atmospheres. Strains of several Aeromonas species have shown spoilage potential by the production of spoilage associated metabolites in various seafood products, but the knowledge on spoilage in cold water fish species is scarce. The question about the significance of Aeromonas spp. in RTE seafood products is challenged by the limited knowledge on how to identify the truly virulent strains. The limited information on clinically relevant strains is partly due to few registered outbreaks, and to the disputed role as a true foodborne pathogen. However, it is likely that illness caused by Aeromonas might go on undetected due to unreported cases and a lack of adequate identification schemes. A rather confusing taxonomy and inadequate biochemical tests for species identification has led to a biased focus towards some Aeromonas species. Over the last ten years, several housekeeping genes has replaced the 16S rRNA gene as suitable genetic markers for phylogenetic analysis. The result is a more clear and robust taxonomy and updated knowledge on the currently circulating environmental strains. Nevertheless, more knowledge on which factors that contribute to virulence and how to control the potential pathogenic strains of Aeromonas in perishable RTE seafood products are needed.
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Affiliation(s)
- Sunniva Hoel
- Department of Biotechnology and Food Science, NTNU⁻Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
| | - Olav Vadstein
- Department of Biotechnology and Food Science, NTNU⁻Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
| | - Anita N Jakobsen
- Department of Biotechnology and Food Science, NTNU⁻Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
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Jung-Schroers V, Jung A, Ryll M, Bauer J, Teitge F, Steinhagen D. Diagnostic methods for identifying different Aeromonas species and examining their pathogenicity factors, their correlation to cytotoxicity and adherence to fish mucus. J Fish Dis 2019; 42:189-219. [PMID: 30521094 DOI: 10.1111/jfd.12917] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/28/2018] [Accepted: 09/28/2018] [Indexed: 06/09/2023]
Abstract
Aeromonas spp. are ubiquitous in the aquatic environment, acting as facultative or obligate pathogens for fish. Identifying Aeromonas spp. is important for pathogenesis and prognosis in diagnostic cases but can be difficult because of their close relationship. Forty-four already characterized isolates of Aeromonas spp. were analysed by 16S rRNA gene sequencing, by gyrase B sequencing, by analysing their fatty acid profiles, by biochemical reactions and by MALDI-TOF MS. To determine their pathogenicity, cytotoxicity, adhesion to mucus and the expression of 12 virulence factors were tested. The susceptibility of the isolates towards 13 different antibiotics was determined. MALDI-TOF MS was found to be an acceptable identification method for Aeromonas spp. Although the method does not detect all species correctly, it is time-effective and entails relatively low costs and no other methods achieved better results. A high prevalence of virulence-related gene fragments was detected in almost all examined Aeromonas spp., especially in A. hydrophila and A. salmonicida, and most isolates exhibited a cytotoxic effect. Single isolates of A. hydrophila and A. salmonicida showed multiple resistance to antibiotics. These results might indicate the potentially pathogenic capacity of Aeromonas spp., suggesting a risk for aquatic animals and even humans, given their ubiquitous nature.
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Affiliation(s)
- Verena Jung-Schroers
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
| | - Arne Jung
- Clinic for Poultry, University of Veterinary Medicine, Hannover, Germany
| | - Martin Ryll
- Clinic for Poultry, University of Veterinary Medicine, Hannover, Germany
| | - Julia Bauer
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
| | - Felix Teitge
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
| | - Dieter Steinhagen
- Fish Disease Research Unit, University of Veterinary Medicine, Hannover, Germany
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Wamala SP, Mugimba KK, Dubey S, Takele A, Munang'andu HM, Evensen Ø, Mutoloki S, Byarugaba DK, Sørum H. Multilocus sequence analysis revealed a high genotypic diversity of Aeromonas hydrophila infecting fish in Uganda. J Fish Dis 2018; 41:1589-1600. [PMID: 30074242 DOI: 10.1111/jfd.12873] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/16/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
A multilocus sequence analysis (MLSA) was carried out to delineate Aeromonas hydrophila from fish in Uganda. Five housekeeping genes including recA, gyrB, metG, gltA and pps; and the 16S rRNA gene were amplified and sequenced from a total of nine A. hydrophila isolates. The obtained sequences were edited, and consensus sequences generated for each gene locus. The housekeeping gene sequences were concatenated and phylogenetic analysis performed in MEGA version 7.0.2. Pairwise distances ranged from 0.000 to 0.118, highest within the gltA gene locus and lowest within the 16S rRNA gene. The average evolutionary diversity within isolates from the same source ranged between 0.002 and 0.037, and it was 0.033 between the different sources. Similar tree topologies were obtained from the different gene loci with recA, metG and gyrB being more consistent in discriminating isolates according to sources while the 16S rRNA gene had the lowest resolution. The concatenated tree had the highest discriminatory power. This study revealed that A. hydrophila strains infecting fish in Uganda are of diverse genotypes suggesting different sources of infection in a given outbreak. Efforts to minimize spread of the bacteria across sources should be emphasized to control infections of mixed genotypes.
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Affiliation(s)
- Samuel Posian Wamala
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Kizito Kahoza Mugimba
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Saurabh Dubey
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Abayneh Takele
- National Veterinary Institute, Bishoftu, Ethiopia
- Cumming School of Medicine, University of Calgary, Calgary, Canada
| | | | - Øystein Evensen
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Stephen Mutoloki
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Denis Karuhize Byarugaba
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Henning Sørum
- Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
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Puah SM, Khor WC, Kee BP, Tan JAMA, Puthucheary SD, Chua KH. Development of a species-specific PCR-RFLP targeting rpoD gene fragment for discrimination of Aeromonas species. J Med Microbiol 2018; 67:1271-1278. [PMID: 30024365 DOI: 10.1099/jmm.0.000796] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE The taxonomy of Aeromonas keeps expanding and their identification remains problematic due to their phenotypic and genotypic heterogeneity. In this study, we aimed to develop a rapid and reliable polymerase chain reaction-restriction fragment length polymorphism assay targeting the rpoD gene to enable the differentiation of aeromonads into 27 distinct species using microfluidic capillary electrophoresis. METHODOLOGY A pair of degenerate primers (Aero F: 5'-YGARATCGAYATCGCCAARCGB-3' and Aero R: 5'-GRCCDATGCTCATRCGRCGGTT-3') was designed that amplified the rpoD gene of 27 Aeromonas species. Subsequently, in silico analysis enabled the differentiation of 25 species using the single restriction endonuclease AluI, while 2 species, A. sanarelli and A. taiwanensis, required an additional restriction endonuclease, HpyCH4IV. Twelve type strains (A. hydrophila ATCC7966T, A. caviae ATCC15468T, A. veronii ATCC9071T, A. media DSM4881T, A. allosaccharophila DSM11576T, A. dhakensis DSM17689T, A. enteropelogens DSM7312T, A. jandaei DSM7311T, A. rivuli DSM22539T, A. salmonicida ATCC33658T, A. taiwanensis DSM24096T and A. sanarelli DSM24094T) were randomly selected from the 27 Aeromonas species for experimental validation.Results/key findings. The twelve type strains demonstrated distinctive RFLP patterns and supported the in silico digestion. Subsequently, 60 clinical and environmental strains from our collection, comprising nine Aeromonas species, were used for screening examinations, and the results were in agreement. CONCLUSION This method provides an alternative method for laboratory identification, surveillance and epidemiological investigations of clinical and environmental specimens.
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Affiliation(s)
- Suat Moi Puah
- 1Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Wei Ching Khor
- 1Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Boon Pin Kee
- 1Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | | | - Kek Heng Chua
- 1Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Navarro A, Martínez-Murcia A. Phylogenetic analyses of the genusAeromonasbased on housekeeping gene sequencing and its influence on systematics. J Appl Microbiol 2018; 125:622-631. [DOI: 10.1111/jam.13887] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/14/2018] [Accepted: 04/11/2018] [Indexed: 11/27/2022]
Affiliation(s)
- A. Navarro
- Genetic Analysis Strategies S.L.; CEEI; Elche, Alicante Spain
| | - A. Martínez-Murcia
- Genetic Analysis Strategies S.L.; CEEI; Elche, Alicante Spain
- Area de Microbiología; EPSO; Universidad Miguel Hernández; Orihuela, Alicante Spain
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Khor WC, Puah SM, Koh TH, Tan JAMA, Puthucheary SD, Chua KH. Comparison of Clinical Isolates of Aeromonas from Singapore and Malaysia with Regard to Molecular Identification, Virulence, and Antimicrobial Profiles. Microb Drug Resist 2018; 24:469-78. [DOI: 10.1089/mdr.2017.0083] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Hoel S, Vadstein O, Jakobsen AN. Species Distribution and Prevalence of Putative Virulence Factors in Mesophilic Aeromonas spp. Isolated from Fresh Retail Sushi. Front Microbiol 2017; 8:931. [PMID: 28596762 PMCID: PMC5442234 DOI: 10.3389/fmicb.2017.00931] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/08/2017] [Indexed: 12/25/2022] Open
Abstract
Aeromonas spp. are ubiquitous bacteria that have received increasing attention as human pathogens because of their widespread occurrence in food, especially seafood and vegetables. The aim of this work was to assess the species identity and phylogenetic relationship of 118 Aeromonas strains isolated from fresh retail sushi from three producers, and to characterize the isolates with respect to genetic and phenotypic virulence factors. We also evaluate the potential hazard associated with their presence in ready-to-eat seafood not subjected to heat treatment. Mesophilic Aeromonas salmonicida was most prevalent (74%), followed by A. bestiarum (9%), A. dhakensis (5%), A. caviae (5%), A. media (4%), A. hydrophila (2%), and A. piscicola (1%). All isolates were considered potentially pathogenic due to the high prevalence of genes encoding hemolysin (hlyA) (99%), aerolysin (aerA) (98%), cytotoxic enterotoxin (act) (86%), heat-labile cytotonic enterotoxin (alt) (99%), and heat-stable cytotonic enterotoxin (ast) (31%). The shiga-like toxins 1 and 2 (stx-1 and stx-2) were not detected. Moreover, there was heterogeneity in toxin gene distribution among the isolates, and the combination of act/alt/hlyA/aerA was most commonly detected (63%). β-hemolysis was species-dependent and observed in 91% of the isolates. All A. media and A. caviae strains were non-hemolytic. For isolates belonging to this group, lack of hemolysis was possibly related to the absence of the act gene. Swimming motility, linked to adhesion and host invasion, occurred in 65% of the isolates. Partial sequencing of the gyrB gene demonstrated its suitability as a genetic marker for Aeromonas species identification and for assessment of the phylogenetic relationship between the isolates. The gyrB sequence divergence within a given species ranged from 1.3 to 2.9%. A. bestiarum, A. salmonicida, and A. piscicola were the most closely related species; their sequences differed by 2.7-3.4%. The average gyrB sequence similarity between all species was 93%, demonstrating its acceptable taxonomic resolution. The presence of multiple species of potential pathogenic Aeromonas in fresh retail sushi raises new food safety issues related to the increased consumption of ready-to-eat food composed of raw ingredients.
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Affiliation(s)
- Sunniva Hoel
- Department of Biotechnology and Food Science, Norwegian University of Science and TechnologyTrondheim, Norway
| | - Olav Vadstein
- Department of Biotechnology and Food Science, Norwegian University of Science and TechnologyTrondheim, Norway
| | - Anita N Jakobsen
- Department of Biotechnology and Food Science, Norwegian University of Science and TechnologyTrondheim, Norway
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15
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Forn-Cuní G, Merino S, Tomás JM. Comparative Genomics of the Aeromonadaceae Core Oligosaccharide Biosynthetic Regions. Int J Mol Sci 2017; 18:E519. [PMID: 28264491 DOI: 10.3390/ijms18030519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 02/23/2017] [Accepted: 02/26/2017] [Indexed: 01/25/2023] Open
Abstract
Lipopolysaccharides (LPSs) are an integral part of the Gram-negative outer membrane, playing important organizational and structural roles and taking part in the bacterial infection process. In Aeromonas hydrophila, piscicola, and salmonicida, three different genomic regions taking part in the LPS core oligosaccharide (Core-OS) assembly have been identified, although the characterization of these clusters in most aeromonad species is still lacking. Here, we analyse the conservation of these LPS biosynthesis gene clusters in the all the 170 currently public Aeromonas genomes, including 30 different species, and characterise the structure of a putative common inner Core-OS in the Aeromonadaceae family. We describe three new genomic organizations for the inner Core-OS genomic regions, which were more evolutionary conserved than the outer Core-OS regions, which presented remarkable variability. We report how the degree of conservation of the genes from the inner and outer Core-OS may be indicative of the taxonomic relationship between Aeromonas species.
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16
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Guo S, Yang Q, Feng J, Duan L, Zhao J. Phylogenetic analysis of the pathogenic genus Aeromonas spp. isolated from diseased eels in China. Microb Pathog 2016; 101:12-23. [DOI: 10.1016/j.micpath.2016.10.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/07/2016] [Accepted: 10/24/2016] [Indexed: 11/21/2022]
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17
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Latif-Eugenín F, Beaz-Hidalgo R, Figueras M. Evaluation of different conditions and culture media for the recovery ofAeromonasspp. from water and shellfish samples. J Appl Microbiol 2016; 121:883-91. [DOI: 10.1111/jam.13210] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/08/2016] [Accepted: 06/20/2016] [Indexed: 12/01/2022]
Affiliation(s)
- F. Latif-Eugenín
- Unidad de Microbiología; Facultad de Medicina y Ciencias de la Salud; IISPV; Universidad Rovira i Virgili; Reus Spain
| | - R. Beaz-Hidalgo
- Unidad de Microbiología; Facultad de Medicina y Ciencias de la Salud; IISPV; Universidad Rovira i Virgili; Reus Spain
| | - M.J. Figueras
- Unidad de Microbiología; Facultad de Medicina y Ciencias de la Salud; IISPV; Universidad Rovira i Virgili; Reus Spain
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Sharma SCD, Feng C, Li J, Hu A, Wang H, Qin D, Yu CP. Electrochemical Characterization of a Novel Exoelectrogenic Bacterium Strain SCS5, Isolated from a Mediator-Less Microbial Fuel Cell and Phylogenetically Related to Aeromonas jandaei. Microbes Environ 2016; 31:213-25. [PMID: 27396922 PMCID: PMC5017797 DOI: 10.1264/jsme2.me15185] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A facultative anaerobic bacterium, designated as strain SCS5, was isolated from the anodic biofilm of a mediator-less microbial fuel cell using acetate as the electron donor and α-FeOOH as the electron acceptor. The isolate was Gram-negative, motile, and shaped as short rods (0.9-1.3 μm in length and 0.4-0.5 μm in width). A phylogenetic analysis of the 16S rRNA, gyrB, and rpoD genes suggested that strain SCS5 belonged to the Aeromonas genus in the Aeromonadaceae family and exhibited the highest 16S rRNA gene sequence similarity (99.45%) with Aeromonas jandaei ATCC 49568. However, phenotypic, cellular fatty acid profile, and DNA G+C content analyses revealed that there were some distinctions between strain SCS5 and the type strain A. jandaei ATCC 49568. The optimum growth temperature, pH, and NaCl (%) for strain SCS5 were 35°C, 7.0, and 0.5% respectively. The DNA G+C content of strain SCS5 was 59.18%. The isolate SCS5 was capable of reducing insoluble iron oxide (α-FeOOH) and transferring electrons to extracellular material (the carbon electrode). The electrochemical activity of strain SCS5 was corroborated by cyclic voltammetry and a Raman spectroscopic analysis. The cyclic voltammogram of strain SCS5 revealed two pairs of oxidation-reduction peaks under anaerobic and aerobic conditions. In contrast, no redox pair was observed for A. jandaei ATCC 49568. Thus, isolated strain SCS5 is a novel exoelectrogenic bacterium phylogenetically related to A. jandaei, but shows distinct electrochemical activity from its close relative A. jandaei ATCC 49568.
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Affiliation(s)
- Subed Chandra Dev Sharma
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences
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19
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Ott BM, Dacks AM, Ryan KJ, Rio RV. A Tale of Transmission: Aeromonas veronii Activity within Leech-Exuded Mucus. Appl Environ Microbiol 2016; 82:2644-55. [PMID: 26896136 DOI: 10.1128/AEM.00185-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/16/2016] [Indexed: 11/20/2022] Open
Abstract
Transmission, critical to the establishment and persistence of host-associated microbiotas, also exposes symbionts to new environmental conditions. With horizontal transmission, these different conditions represent major lifestyle shifts. Yet genome-wide analyses of how microbes adjust their transcriptomes toward these dramatic shifts remain understudied. Here, we provide a comprehensive and comparative analysis of the global transcriptional profiles of a symbiont as it shifts between lifestyles during transmission. The gammaproteobacterium Aeromonas veronii is transmitted from the gut of the medicinal leech to other hosts via host mucosal castings, yet A. veronii can also transition from mucosal habitancy to a free-living lifestyle. These three lifestyles are characterized by distinct physiological constraints and consequently lifestyle-specific changes in the expression of stress-response genes. Mucus-bound A. veronii had the greatest expression in terms of both the number of loci and levels of transcription of stress-response mechanisms. However, these bacteria are still capable of proliferating within the mucus, suggesting the availability of nutrients within this environment. We found that A. veronii alters transcription of loci in a synthetic pathway that obtains and incorporates N-acetylglucosamine (NAG; a major component of mucus) into the bacterial cell wall, enabling proliferation. Our results demonstrate that symbionts undergo dramatic local adaptation, demonstrated by widespread transcriptional changes, throughout the process of transmission that allows them to thrive while they encounter new environments which further shape their ecology and evolution.
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20
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Albarral V, Sanglas A, Palau M, Miñana-Galbis D, Fusté MC. Potential pathogenicity ofAeromonas hydrophilacomplex strains isolated from clinical, food, and environmental sources. Can J Microbiol 2016; 62:296-306. [DOI: 10.1139/cjm-2015-0466] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aeromonas are autochthonous inhabitants of aquatic environments, including chlorinated and polluted waters, although they can also be isolated from a wide variety of environmental and clinical sources. They cause infections in vertebrates and invertebrates and are considered to be an emerging pathogen in humans, producing intestinal and extra-intestinal diseases. Most of the clinical isolates correspond to A. hydrophila, A. caviae, and A. veronii bv. Sobria, which are described as the causative agents of wound infections, septicaemia, and meningitis in immunocompromised people, and diarrhoea and dysenteric infections in the elderly and children. The pathogenic factors associated with Aeromonas are multifactorial and involve structural components, siderophores, quorum-sensing mechanisms, secretion systems, extracellular enzymes, and exotoxins. In this study, we analysed a representative number of clinical and environmental strains belonging to the A. hydrophila species complex to evaluate their potential pathogenicity. We thereby detected their enzymatic activities and antibiotic susceptibility pattern and the presence of virulence genes (aer, alt, ast, and ascV). The notably high prevalence of these virulence factors, even in environmental strains, indicated a potential pathogenic capacity. Additionally, we determined the adhesion capacity and cytopathic effects of this group of strains in Caco-2 cells. Most of the strains exhibited adherence and caused complete lysis.
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Affiliation(s)
- Vicenta Albarral
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona 08028, Spain
| | - Ariadna Sanglas
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona 08028, Spain
| | - Montserrat Palau
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona 08028, Spain
| | - David Miñana-Galbis
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona 08028, Spain
| | - M. Carmen Fusté
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Avinguda Diagonal 643, Barcelona 08028, Spain
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21
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Martínez-Murcia A, Beaz-Hidalgo R, Navarro A, Carvalho MJ, Aravena-Román M, Correia A, Figueras MJ, Saavedra MJ. Aeromonas lusitana sp. nov., Isolated from Untreated Water and Vegetables. Curr Microbiol 2016; 72:795-803. [PMID: 26868258 DOI: 10.1007/s00284-016-0997-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 12/16/2015] [Indexed: 11/30/2022]
Abstract
During previous studies to evaluate the phylogenetic diversity of Aeromonas from untreated waters and vegetables intended for human consumption, a group of isolates formed a unique gyrB phylogenetic cluster, separated from those of all other species described so far. A subsequent extensive phenotypic characterization, DNA-DNA hybridization, 16S rRNA gene sequencing, multi-locus phylogenetic analysis of the concatenated sequence of seven housekeeping genes (gyrB, rpoD, recA, dnaJ, gyrA, dnaX, and atpD; 4705 bp), and ERIC-PCR, were performed in an attempt to ascertain the taxonomy position of these isolates. This polyphasic approach confirmed that they belonged to a novel species of the genus Aeromonas, for which the name Aeromonas lusitana sp. nov. is proposed, with strain A.11/6(T) (=DSMZ 24095(T), =CECT 7828(T)) as the type strain.
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Affiliation(s)
- Antonio Martínez-Murcia
- Area de Microbiología, EPSO, Universidad Miguel Hernández, 03312, Orihuela, Alicante, Spain. .,Genetic PCR Solutions TM, CEEI, Elche, Alicante, Spain.
| | - Roxana Beaz-Hidalgo
- Unitat de Microbiologia, Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Aaron Navarro
- Genetic PCR Solutions TM, CEEI, Elche, Alicante, Spain
| | - M João Carvalho
- Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Max Aravena-Román
- School of Pathology and Laboratory Medicine, The University of Western Australia Crawley, Crawley, WA, Australia
| | - Antonio Correia
- Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal
| | - M José Figueras
- Unitat de Microbiologia, Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - M José Saavedra
- Department of Veterinary Sciences, CECAV-University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
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22
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Odeyemi OA, Ahmad A. Antibiotic resistance profiling and phenotyping of Aeromonas species isolated from aquatic sources. Saudi J Biol Sci 2015; 24:65-70. [PMID: 28053573 PMCID: PMC5198916 DOI: 10.1016/j.sjbs.2015.09.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 11/19/2022] Open
Abstract
This study aimed to investigate antibiotics resistance pattern and phenotyping of Aeromonas species isolated from different aquatic sources in Melaka, Malaysia. A total of 53 Aeromonas species were isolated from the following sources: sediment (n = 13), bivalve (n = 10), sea cucumber (n = 16) and sea water (n = 14) and resistance to 12 antibiotics – Tetracycline (30 μg), Kanamycin (30 μg), Oxytetracycline (30 μg), Ampicillin (10 μg), Streptomycin (10 μg), Gentamicin (10 μg), Sulphamethoxazole (25 μg), Nalixidic acid (30 μg), Trimethoprim (1.25 μg), Novobiocin (5 μg), Penicilin (10 μg) and Chloramphenicol (10 μg) was tested. The results obtained from this study reveal multi drug resistance pattern among the isolates. All the isolates were completely resistant to Ampicillin, Novobiocin, Sulphamethoxazole and Trimethoprim, respectively but susceptible to Tetracycline (100%), Kanamycin (5.7%), Gentamicin (5.7%) and Oxytetracycline (24.5%). Antibiotics phenotyping of the bacteria revealed 21 different phenotypes among the isolates.
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Affiliation(s)
- Olumide A. Odeyemi
- Ecology and Biodiversity, Institute of Marine and Antarctic Studies (IMAS), University of Tasmania, Launceston, Australia
- School of Biosciences and Biotechnology, National University of Malaysia, Malaysia
- Corresponding author at: Ecology and Biodiversity, Institute of Marine and Antarctic Studies (IMAS), University of Tasmania, Launceston, Australia.Ecology and BiodiversityInstitute of Marine and Antarctic Studies (IMAS)University of TasmaniaLaunceston, Australia
| | - Asmat Ahmad
- School of Biosciences and Biotechnology, National University of Malaysia, Malaysia
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23
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Beaz-Hidalgo R, Latif-Eugenín F, Hossain M, Berg K, Niemi R, Rapala J, Lyra C, Liles M, Figueras M. Aeromonas aquatica sp. nov., Aeromonas finlandiensis sp. nov. and Aeromonas lacus sp. nov. isolated from Finnish waters associated with cyanobacterial blooms. Syst Appl Microbiol 2015; 38:161-8. [DOI: 10.1016/j.syapm.2015.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 02/18/2015] [Accepted: 02/27/2015] [Indexed: 10/23/2022]
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Abstract
Aeromonas spp. são bactérias Gram negativas, opor-tunistas, de natureza ubíqua, isoladas principalmente de amostras de água. Até o presente momento foram reconhecidas 31 espé-cies, sendo as de maior importância médica Aeromonas hydrophila, Aeromonas caviae e Aeromonas veronii. A patogenicidade do gênero é considerada multifatorial, sendo este produtor de diversos tipos de toxinas e com envolvimento de outros fatores capazes de facilitar a penetração e o estabelecimento do agente no hospedeiro, causando doença. O objetivo desta revisão é elucidar o papel dos alimentos de origem animal como fontes de contaminação de bactérias do gênero Aeromonas para o ser humano. Isolamentos de aeromonas de diversos produtos de origem animal têm sido relatados, como carne, leite e seus derivados, além de frutos do mar, e em ambientes de processamento, como abatedouros, frigorífcos e laticínios. Tem-se buscado determinar fontes de contaminação dos alimentos, e a água foi definida como o principal disseminador. Aeromonas já foi defnida como sendo a causadora de diversas enfermidades, desde afecções gastrointestinais até casos de meningite e morte. Considerando os alimentos de origem animal como importantes veículos de transmissão para o ser humano e o reconhecimento da água como fonte de disseminação do agente, torna-se imprescindível o tratamento adequado da água utilizada nos estabelecimentos processadores de alimentos para a segurança alimentar.
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Vávrová A, Balážová T, Sedláček I, Tvrzová L, Šedo O. Evaluation of the MALDI-TOF MS profiling for identification of newly described Aeromonas spp. Folia Microbiol (Praha) 2014; 60:375-83. [DOI: 10.1007/s12223-014-0369-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 12/02/2014] [Indexed: 11/29/2022]
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26
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Zhang DF, Zhang QQ, Li AH. Development of a multiplex PCR assay for rapid and simultaneous detection of four genera of fish pathogenic bacteria. Lett Appl Microbiol 2014; 59:471-8. [PMID: 25041355 DOI: 10.1111/lam.12303] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/04/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED Species of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus are the most common fish pathogenic bacteria that cause economically devastating losses in aquaculture. A multiplex polymerase chain reaction (mPCR) was developed for the simultaneous detection and differentiation of the four genera of fish pathogenic bacteria. Through the use of genus-specific primers instead of species-specific ones, the current mPCR covered much more target bacterial species compared with previously reported species-specific mPCR methods. The specificity of the four putative genus-specific primers was validated experimentally while used exclusively (uniplex PCR) or combined (mPCR) against bacterial genomic DNA templates of the target bacteria and nontarget bacteria. The PCR amplicons for the following genera were obtained as expected: Aeromonas (875 bp), Vibrio (524 bp), Edwardsiella (302 bp) and Streptococcus (197 bp), and the fragments could be separated clearly on the agarose gel electrophoresis. The mPCR did not produce nonspecific amplification products when used to amplify 21 nontarget species of bacteria. The mPCR detection limits for each target bacterial genera were 50 colony-forming units (CFU) in pure culture and 100 CFU in fish tissue samples. In conclusion, the mPCR assay was proven to be a powerful alternative to the conventional culture-based method, given its rapid, specific, sensitive and reliable detection of target pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY The fish pathogenic bacteria of genus Aeromonas, Vibrio, Edwardsiella and Streptococcus frequently cause severe outbreaks of diseases in cultured fish, and the genus-specific multiplex PCR assay developed in this study can detect the bacteria of the four genera when present in the samples either alone or mixed. The mPCR assay is expected to identify the causative agents more efficiently than uniplex PCR or species-specific multiplex PCR for clinical diagnosis, resulting in the earlier implementation of control measures. This mPCR assay provides a rapid, specific and sensitive tool for the detection or identification of common fish pathogenic bacteria in aquaculture practice.
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Affiliation(s)
- D F Zhang
- Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Aravena-Román M, Beaz-Hidalgo R, Inglis TJJ, Riley TV, Martínez-Murcia AJ, Chang BJ, Figueras MJ. Aeromonas australiensis sp. nov., isolated from irrigation water. Int J Syst Evol Microbiol 2013; 63:2270-2276. [DOI: 10.1099/ijs.0.040162-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-negative, facultatively anaerobic bacillus, designated strain 266T, was isolated from an irrigation water system in the south-west of Western Australia. Analysis of the 16S rRNA gene sequence confirmed that strain 266T belonged to the genus
Aeromonas
, with the nearest species being
Aeromonas fluvialis
(99.6 % similarity to the type strain, with 6 nucleotide differences) followed by
Aeromonas veronii
and
Aeromonas allosaccharophila
(both 99.5 %). Analysis of gyrB and rpoD sequences suggested that strain 266T formed a phylogenetic line independent of other species in the genus. This was confirmed using the concatenated sequences of six housekeeping genes (gyrB, rpoD, recA, dnaJ, gyrA and dnaX) that also indicated that
A. veronii
and
A. allosaccharophila
were the nearest relatives. DNA–DNA reassociation experiments and phenotypic analysis further supported the conclusion that strain 266T represents a novel species, for which the name Aeromonas australiensis sp. nov. is proposed, with type strain 266T ( = CECT 8023T = LMG 2670T).
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Affiliation(s)
- Max Aravena-Román
- Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine, Nedlands, WA, Australia
- School of Pathology and Laboratory Medicine, the University of Western Australia, Crawley, WA, Australia
| | - Roxana Beaz-Hidalgo
- Unitat de Microbiologia, Department de Ciènces Mèdiques Básiques, Facultat de Medicina i Ciènces de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Timothy J. J. Inglis
- Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine, Nedlands, WA, Australia
- School of Pathology and Laboratory Medicine, the University of Western Australia, Crawley, WA, Australia
| | - Thomas V. Riley
- Division of Microbiology and Infectious Diseases, PathWest Laboratory Medicine, Nedlands, WA, Australia
- School of Pathology and Laboratory Medicine, the University of Western Australia, Crawley, WA, Australia
| | - Antonio J. Martínez-Murcia
- Departamento de Producción Vegetal y Microbiología, EPSO, Universidad Miguel Hernández, Orihuela 03312 (Alicante), Spain
| | - Barbara J. Chang
- School of Pathology and Laboratory Medicine, the University of Western Australia, Crawley, WA, Australia
| | - Maria Jose Figueras
- Unitat de Microbiologia, Department de Ciènces Mèdiques Básiques, Facultat de Medicina i Ciènces de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
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Huddleston JR, Brokaw JM, Zak JC, Jeter RM. Natural transformation as a mechanism of horizontal gene transfer among environmental Aeromonas species. Syst Appl Microbiol 2013; 36:224-34. [PMID: 23541366 DOI: 10.1016/j.syapm.2013.01.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 01/15/2013] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
Abstract
Aeromonas species are common inhabitants of aquatic environments and relevant as human pathogens. Their potential as pathogens may be related in part to lateral transfer of genes associated with toxin production, biofilm formation, antibiotic resistance, and other virulence determinants. Natural transformation has not been characterized in aeromonads. DNA from wild-type, prototrophic strains that had been isolated from environmental sources was used as donor DNA in transformation assays with auxotrophs as the recipients. Competence was induced in 20% nutrient broth during the stationary phase of growth. Optimal transformation assay conditions for one chosen isolate were in Tris buffer with magnesium or calcium, pH 5-8, and a saturating concentration of 0.5 μg of DNA per assay (3.3 ng of DNA μl⁻¹) at 30°C. Sodium was also required and could not be replaced with ammonium, potassium, or lithium. The maximal transformation frequency observed was 1.95 × 10⁻³ transformants (recipient cell)⁻¹. A survey of environmental Aeromonas auxotrophic recipients (n=37), assayed with donor DNA from other wild-type environmental aeromonads under optimal assay conditions, demonstrated that 73% were able to act as recipients, and 100% were able to act as donors to at least some other aeromonads. Three different transformation groups were identified based on each isolates' ability to transform other strains with its DNA. The transformation groups roughly corresponded to phylogenetic groups. These results demonstrate that natural transformation is a general property of Aeromonas environmental isolates with implications for the genetic structures of coincident Aeromonas populations.
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Affiliation(s)
- Jennifer R Huddleston
- Biology Department, ACU Box 27868, Abilene Christian University, Abilene, Texas 79699, USA.
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Martínez-Murcia A, Beaz-Hidalgo R, Svec P, Saavedra MJ, Figueras MJ, Sedlacek I. Aeromonas cavernicola sp. nov., isolated from fresh water of a brook in a cavern. Curr Microbiol 2012; 66:197-204. [DOI: 10.1007/s00284-012-0253-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 10/01/2012] [Indexed: 12/19/2022]
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Beaz-Hidalgo R, Shakèd T, Laviad S, Halpern M, Figueras MJ. Chironomid egg masses harbour the clinical speciesAeromonas taiwanensisandAeromonas sanarellii. FEMS Microbiol Lett 2012; 337:48-54. [DOI: 10.1111/1574-6968.12003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 08/07/2012] [Accepted: 09/05/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Roxana Beaz-Hidalgo
- Facultat de Medicina i Ciències de la Salut; Departament de Ciènces Médiques Bàsiques; Unitat de Microbiologia; IISPV; Universitat Rovira i Virgili; Reus; Spain
| | - Tamar Shakèd
- Faculty of Natural Sciences; Department of Biology; University of Haifa; Oranim; Tivon; Israel
| | - Sivan Laviad
- Faculty of Natural Sciences; Department of Biology; University of Haifa; Oranim; Tivon; Israel
| | - Malka Halpern
- Faculty of Natural Sciences; Department of Biology; University of Haifa; Oranim; Tivon; Israel
| | - María J. Figueras
- Facultat de Medicina i Ciències de la Salut; Departament de Ciènces Médiques Bàsiques; Unitat de Microbiologia; IISPV; Universitat Rovira i Virgili; Reus; Spain
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Roger F, Lamy B, Jumas-Bilak E, Kodjo A, Marchandin H. Ribosomal multi-operon diversity: an original perspective on the genus Aeromonas. PLoS One 2012; 7:e46268. [PMID: 23032081 PMCID: PMC3459834 DOI: 10.1371/journal.pone.0046268] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/28/2012] [Indexed: 12/31/2022] Open
Abstract
16S rRNA gene (rrs) is considered of low taxonomic interest in the genus Aeromonas. Here, 195 Aeromonas strains belonging to populations structured by multilocus phylogeny were studied using an original approach that considered Ribosomal Multi-Operon Diversity. This approach associated pulsed-field gel electrophoresis (PFGE) to assess rrn operon number and distribution across the chromosome and PCR-temporal temperature gel electrophoresis (TTGE) to assess rrs V3 region heterogeneity. Aeromonads harbored 8 to 11 rrn operons, 10 operons being observed in more than 92% of the strains. Intraspecific variability was low or nul except for A. salmonicida and A. aquariorum suggesting that large chromosomic rearrangements might occur in these two species while being extremely rarely encountered in the evolution of other taxa. rrn operon number at 8 as well as PFGE patterns were shown valuable for taxonomic purpose allowing resolution of species complexes. PCR-TTGE revealed a high rate of strains (41.5%) displaying intragenomic rrs heterogeneity. Strains isolated from human samples more frequently displayed intragenomic heterogeneity than strains recovered from non-human and environmental specimens. Intraspecific variability ranged from 0 to 76.5% of the strains. The observation of species-specific TTGE bands, the recovery of identical V3 regions in different species and the variability of intragenomic heterogeneity (1-13 divergent nucleotides) supported the occurrence of mutations and horizontal transfer in aeromonad rrs evolution. Altogether, the presence of a high number of rrn operon, the high proportion of strains harboring divergent rrs V3 region and the previously demonstrated high level of genetic diversity argued in favor of highly adaptative capabilities of aeromonads. Outstanding features observed for A. caviae supported the ongoing process of adaptation to a specialized niche represented by the gut, previously hypothesized. 16S rRNA gene is an informative marker in the genus Aeromonas for both evolutionary and polyphasic taxonomic studies provided that multi-operon fingerprinting approaches are used.
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Affiliation(s)
- Frédéric Roger
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
| | - Brigitte Lamy
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire de Bactériologie, Hôpital Arnaud de Villeneuve, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
- Groupe d’Etude Français des Aeromonas (GFA), Lyon, France
| | - Estelle Jumas-Bilak
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire d’Hygiène hospitalière, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
| | - Angeli Kodjo
- Groupe d’Etude Français des Aeromonas (GFA), Lyon, France
- CNRS UMR 5557 Ecologie microbienne, VetAgro Sup Campus vétérinaire de Lyon, Université Claude Bernard Lyon 1, Marcy-l’Étoile, France
| | | | - Hélène Marchandin
- UMR 5119 ECOSYM, Equipe Pathogènes et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier 1, Montpellier, France
- Laboratoire de Bactériologie, Hôpital Arnaud de Villeneuve, Centre Hospitalier Régional Universitaire de Montpellier, Montpellier, France
- * E-mail:
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Sreedharan K, Philip R, Singh ISB. Characterization and virulence potential of phenotypically diverse Aeromonas veronii isolates recovered from moribund freshwater ornamental fishes of Kerala, India. Antonie van Leeuwenhoek 2013; 103:53-67. [DOI: 10.1007/s10482-012-9786-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/27/2012] [Indexed: 12/19/2022]
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Fontes M, Martins C, Martínez-Murcia A, Saavedra M. Phylogenetic Diversity ofAeromonasfrom “Alheira,” a Traditional Portuguese Meat Product. Foodborne Pathog Dis 2012; 9:713-8. [DOI: 10.1089/fpd.2011.1103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- M.C. Fontes
- Center of Studies in Animal and Veterinary Science (CECAV), Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - C. Martins
- Center of Studies in Animal and Veterinary Science (CECAV), Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - A.J. Martínez-Murcia
- Departament of Plant Production and Microbiology, University of Miguel Hernández, Alicante, Spain
| | - M.J. Saavedra
- Center of Studies in Animal and Veterinary Science (CECAV), Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro, Vila Real, Portugal
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Hu M, Wang N, Pan ZH, Lu CP, Liu YJ. Identity and virulence properties of Aeromonas isolates from diseased fish, healthy controls and water environment in China. Lett Appl Microbiol 2012; 55:224-33. [PMID: 22725694 DOI: 10.1111/j.1472-765x.2012.03281.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M Hu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
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Abstract
Eight Aeromonas hydrophila-like arabinose-negative isolates from diverse sources (i.e., river freshwater, cooling-system water pond, diseased wild European eels, and human stools) sampled in Valencia (Spain) during 2004–2005, were characterized by 16S rRNA gene sequencing and extensive biochemical testing along with reference strains of most Aeromonas species. These isolates and all reference strains of A. hydrophila subsp. dhakensis and A. aquariorum showed a 16S rRNA sequence similarity of 99.8–100%, and they all shared an identical phenotype. This matched exactly with that of A. hydrophila subsp. dhakensis since all strains displayed positive responses to the Voges-Prokauer test and to the use of dl-lactate. This is the first report of A. hydrophila subsp. dhakensis recovered from environmental samples, and further, from its original isolation in India during 1993–1994. This was accurately identified and segregated from other clinical aeromonads (A. hydrophila subsp. hydrophila, A. caviae, A. veronii biovars veronii and sobria, A. trota, A. schubertii and A. jandaei) by using biochemical key tests. The API 20 E profile for all strains included in A. hydrophila subsp. dhakensis was 7047125. The prevalence of this species in Spanish sources was higher for water (9.4%) than for feces (6%) or eels (1.3%). Isolates recovered as pure cultures from diseased eels were moderately virulent (LD50 of 3.3×106 CFU fish−1) to challenged eels in experimental trials. They were all resistant to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and imipenem, regardless of its source. Our data point to A. hydrophila subsp. dhakensis as an emerging pathogen for humans and fish in temperate countries.
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Affiliation(s)
- Consuelo Esteve
- Departamento de Microbiología y Ecología, Universitat de València, E-46100 Burjassot, Valencia, Spain.
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Martino ME, Fasolato L, Montemurro F, Rosteghin M, Manfrin A, Patarnello T, Novelli E, Cardazzo B. Determination of microbial diversity of Aeromonas strains on the basis of multilocus sequence typing, phenotype, and presence of putative virulence genes. Appl Environ Microbiol 2011; 77:4986-5000. [PMID: 21642403 DOI: 10.1128/AEM.00708-11] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The genus Aeromonas has been described as comprising several species associated with the aquatic environment, which represents their principal reservoir. Aeromonas spp. are commonly isolated from diseased and healthy fish, but the involvement of such bacteria in human infection and gastroenteritis has frequently been reported. The primary challenge in establishing an unequivocal link between the Aeromonas genus and pathogenesis in humans is the extremely complicated taxonomy. With the aim of clarifying taxonomic relationships among the strains and phenotypes, a multilocus sequencing approach was developed and applied to characterize 23 type and reference strains of Aeromonas spp. and a collection of 77 field strains isolated from fish, crustaceans, and mollusks. All strains were also screened for putative determinants of virulence by PCR (ast, ahh1, act, asa1, eno, ascV, and aexT) and the production of acylated homoserine lactones (AHLs). In addition, the phenotypic fingerprinting obtained from 29 biochemical tests was submitted to the nonparametric combination (NPC) test methodology to define the statistical differences among the identified genetic clusters. Multilocus sequence typing (MLST) achieved precise strain genotyping, and the phylogenetic analysis of concatenated sequences delineated the relationship among the taxa belonging to the genus Aeromonas, providing a powerful tool for outbreak traceability, host range diffusion, and ecological studies. The NPC test showed the feasibility of phenotypic differentiation among the majority of the MLST clusters by using a selection of tests or the entire biochemical fingerprinting. A Web-based MLST sequence database (http://pubmlst.org/aeromonas) specific for the Aeromonas genus was developed and implemented with all the results.
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Martinez-Murcia AJ, Monera A, Saavedra MJ, Oncina R, Lopez-Alvarez M, Lara E, Figueras MJ. Multilocus phylogenetic analysis of the genus Aeromonas. Syst Appl Microbiol 2011; 34:189-99. [DOI: 10.1016/j.syapm.2010.11.014] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/16/2010] [Accepted: 11/17/2010] [Indexed: 11/29/2022]
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Fontes M, Saavedra M, Martins C, Martínez-murcia A. Phylogenetic identification of Aeromonas from pigs slaughtered for consumption in slaughterhouses at the North of Portugal. Int J Food Microbiol 2011; 146:118-22. [DOI: 10.1016/j.ijfoodmicro.2011.02.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 12/19/2010] [Accepted: 02/08/2011] [Indexed: 11/23/2022]
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Figueras MJ, Borrego JJ. New perspectives in monitoring drinking water microbial quality. Int J Environ Res Public Health 2010; 7:4179-202. [PMID: 21318002 DOI: 10.3390/ijerph7124179] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 12/06/2010] [Indexed: 11/16/2022]
Abstract
The safety of drinking water is evaluated by the results obtained from faecal indicators during the stipulated controls fixed by the legislation. However, drinking-water related illness outbreaks are still occurring worldwide. The failures that lead to these outbreaks are relatively common and typically involve preceding heavy rain and inadequate disinfection processes. The role that classical faecal indicators have played in the protection of public health is reviewed and the turning points expected for the future explored. The legislation for protecting the quality of drinking water in Europe is under revision, and the planned modifications include an update of current indicators and methods as well as the introduction of Water Safety Plans (WSPs), in line with WHO recommendations. The principles of the WSP approach and the advances signified by the introduction of these preventive measures in the future improvement of dinking water quality are presented. The expected impact that climate change will have in the quality of drinking water is also critically evaluated.
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