Aeromonas species grow at a range of temperatures, although they are isolated with increasing frequency during warmer months may through october in the northern hemisphere. Studies on aeromonas hydrophila in cultured oreochromis. Emerging aeromonas species infections and their significance. Aeromonas hydrophila is the most well known of the six species belonging to the genus aeromonas. Aeromonas hydrophila has been known to grow either aerobically or anaerobicly in a wide range of temperatures, conductivities, phs, and turbidities, however, its optimal temperature range is from 25 to 37c. Aeromonas species can cause biliary tract infections in both immunosuppressed and immunocompetent patients. It is rod shaped, non spore forming, oxidase positive, glucose fermenting, facultative anaerobic, gram negative bacterium that inhabits aquatic environments 1, 2. Aeromonas hydrophila is a heterotrophic, gramnegative, rodshaped bacterium mainly found in areas with a warm climate. Aeromonads are of aquatic origin and are found in surface and waste water but. In vitro antimicrobial susceptibility of clinical isolates of. Only three species are of major clinical importance. Aeromonas caviae was the species which presented the highest resistance 29%, followed by a. The efficacy of eight routine enteric agars for supporting the growth of 32 strains of aeromonas spp. Aeromonas is a gramnegative, motile, and facultative anaerobic bacterium.
From the creation of the genus aeromonas in 1943 through the mid1970s, aeromonads could be broken down roughly into two major groupings, based upon growth characteristics and other biochemical features. Isolate nm14 also belonged to the same group, while nm35 was identified as atypical aeromonas species. Also found in untreated and chlorinated drinking water, raw food and raw milk 3,18. Dynamics of aeromonas species isolated from wastewater treatment system article pdf available in journal of water and health 84. Aeromonas species infectious disease and antimicrobial. Aeromonas hydrophila aeromonas salmonicida aeromonas sobria aeromonas sp.
This pathogen was found in the floodwater following hurricane katrina and was also the most common cause of skin and soft tissue. Pdf thirty water samples were collected, at two week intervals, from the estuary of the river coco. The clinical data presented here suggest a clinical significance ofa. Aeromonas species elaborate a wide range of microbial proteases metalloproteases, serine proteases, and aminopeptidases capable of degrading complex biologic proteins present in serum and connective tissue, including albumin, fibrinogen, elastin, and collagen 107, 2, 6, 7. The motile mesophilic aeromonas species are primarily organisms of aquatic environment and are present in fresh water, estuarine and coastal water bodies and even in chlorinated water. Degradation of such tissues and proteins can serve as an.
These organisms are oxidasepositive and facultatively anaerobic. Aeromonas species produce an array of virulence factors including enterotoxins, haemolysin, exoenzymes, siderophores, flagella and secretion mechanisms castilho et al. Aeromonas punctata aeromonas eucrenophila aeromonas jandaei aeromonas media aeromonas schubertii aeromonas veronii aeromonas allosaccharophila aeromonas enteropelogenes aeromonas sp. Identification of clinical aeromonas species by rpob and gyrb. Gastroenteritis is the major clinical illness associated with aeromonas species, although causation and estimates of disease burden are controversial. The 104 isolates were identified by biolog and belonged to 11 different species. The genus aeromonas comprises 14 species, although its taxonomy has not yet been resolved. Aeromonas species are considered opportunistic emergent. Susceptibility pattern of 67 aeromonas isolates is shown in the.
Aeromonas species occur widely in soil and water where these species cause disease in fish and amphibians. Aeromonas species were found in 30% of the water samples and in 10% of the stool. Aeromonas species provider requirements isolate or specimen submission requested acceptable specimen sourcestypes for submission stool culture isolate tdh requisition form number ph4182 media requirements stools. A phylogenetic tree was constructed based on neighbourjoining. On may 1, 1988, isolates of aeromonas became reportable in california, the first state to mandate reporting of isolates of and infections with these organisms. It is a relatively common cause of diarrhoea in this country. The species was exposed as aeromonas hydrophila from esculin hydrolysis test.
The genus aeromonas are made up of straight, coccobacillarytobacillary gramnegative bacteria with surrounding ends measuring 0. Aeromonas article about aeromonas by the free dictionary. They may have had a specimen sent to the laboratory as part of routine tests by their doctor or during a. It is observed that the major cause of gastrointestinal infections by aeromonas species 3, 4 is because of ingesting infected water 5, 6. In vitro antimicrobial susceptibility of clinical isolates. Aeromonas hydrophila this motile species can be freeliving or parasitic. Aeromonas is a new coming reference hardback and ebook that provides an overview on taxonomy, ecology and pathogenicity of the genus aeromonas, a group of bacterial species in the gamma subclass of the proteobacteria i.
Combining the results resulted in detection of aeromonas in 23. Characterization of aeromonas species isolated from an. There are currently 17 recognized species of aeromonas. In contrast toaeromonas hydrophila andaeromonas sobria, this species has been considered to be of little enteropathogenic significance due to the absence of known virulence factors. Aeromonas species were isolated in almost equal number in both sexes 33 males and 34 females. From the isolated strains seven species of aeromonas were identified. Aeromonas is a genus of gramnegative, facultative anaerobic, rodshaped bacteria that morphologically resemble members of the family enterobacteriaceae. Neighborjoining tree constructed from concatenated partial gyrb. Aeromonas species did not favor any predominant area. In this study, we compared pulsedfield gel electrophoresis patterns of aeromonas isolates from stool specimens of patients with. Aeromonas hydrophila is a species of gramnegative bacteria.
Occurrence of potential pathogenic aeromonas species in tropical. Pdf species of aeromonads are nonspore forming, rodshaped, facultatively anaerobic bacteria that occur ubiquitously and autochthonously in aquatic. Aeromonas is an acute diarrhoeal illness that normally clears by itself without treatment. A total of 500 water samples and 150 stool samples were analysed. The most common species isolated is aeromonas hydrophila. Similarly to vibrio parahaemolyticus and legionella pneumophila, this organism is found worldwide throughout aquatic environments including in bottled water, swimming pools, chlorinated water, well. Aeromonas species synthesize a large number of extracellular proteases including metalloprotease and serine protease that are involved in the degradation of different proteinaceous compounds such as albumin, fibrin, gelatin and even native elastin molecules. Multiple drug resistance in aeromonas hydrophila isolates of fish the present results are in concurrence with the reports shakuntala, i. Aeromonas species in tropical seafood, aquafarms and mangroves off. The clinical picture of aeromonas gastroenteritis may vary from acute, profusely watery diarrhea with fever and vomiting to a dysenterylike illness with cramps and abdominal pain, or to mild, chronic diarrhea of more then 10 days duration up to several months. Diarrhea is the most frequent infection with aeromonas spp.
Therefore, this study was planned to fulfill the following objectives. Sv alavandi, s ananthan indian journal of medical microbiology. A molecular identification for aeromonas species using gcat and rpod. Interestingly, based on our biochemical identifications, nm22 stool and nm33 water isolates were identified as belonging to a. Aeromonas hydrophila is a member of the family aeromonadaceae, and is only one of six species aeromonas species that are known to be pathogenic in humans. Species of aeromonas are gramnegative, nonsporeforming, rodshaped, facul tatively anaerobic bacteria that occur ubiquitously and autochthonously in aquatic environments. Morphologically aeromonas are indistinguishable from members of the enterobacteriaceae. The organisms are ubiquitous in fresh and brackish water. The objective of the present study was to delineate the differences between the clinical and environmental aeromonas species with respect to their biochemical characteristics, serogrouping and virulence factors, in order to find a phenotypic marker of enteropathogenicity. This bacterium can be found in fresh or brackish water. Past to present from the creation of the genus aeromonas in 1943 through the mid1970s, aeromonads could be broken down roughly into two major groupings, based upon growth characteristics and other biochemical features 8.
Conventional identification of aeromonas species based on biochemical. The genus aeromonas is a member of the family aeromonadaceae, in the class proteobacteria. Aeromonas species are facultative anaerobic, catalase, and oxidase positive. Studying the seasonal prevalence of aeromonas hydrophila in naturally collected and cultured o. The most common species isolated is aeromonas hydrophila aeromonas can also cause gastroenteritis travellers diarrhoea, meningitis and peritonitis what are the signs of aeromonas skin infection. Review of literature aeromonas species, aquatic, gramnegative bacilli, is distributed globally and grows ubiquitously in the natural environment. Presumptive aeromonas isolates were screened for standard phenotypic traits. Combining the results resulted in detection of aeromonas in 23 samples 77%. Aeromonas was a common wound isolate among tsunami victims in southeast asia in 2004, and elevated numbers of aeromonas spp were recorded in floodwater samples in new orleans following hurricane katrina in 2005 49,50. Currently this group is included in the family aeromonadaceae, at least 17 genomespecies are recognized in the genus 23. Aeromonas are flagellated, facultative, anaerobic, nonsporeforming, catalase and oxidasepositive, gramnegative rods in the family aeromonadaceae. As a consequence, the taxonomic history of the genus aeromonas has been one of confusion and controversy 7, 8, 22, involving not only definition of the species assigned to the genus but also. This organism is probably that which is now known as aeromonas hydrophila. It can survive in aerobic and anaerobic environments, and can digest materials such as gelatin and hemoglobin.
Aeromonas biliary tract infections tend to occur in patients with biliary tract obstruction or stasis due to hepatobiliary cancer or stones 22. The genus aeromonas is composed of a large number of different taxa. Most of the 14 described species have been associated with human diseases. No aeromonas species were isolated from the control group of 500 patients. The distribution of the aeromonas species in the btmu3 and btsq, aligned together to form a studied samples is given in figure 1.
We describe a patient with aeromonas hydrophila infection whose graft was treated with medicinal leeches. Aeromonas hydrophila, aeromonas caviae and aeromonas veronii. Aeromonas infections is therefore complex and multifactorial. Sir, the genus aeromonas comprises 14 species, although its taxonomy has not yet been resolved. Surveillance data for 1988 and 1989 represent the first. Aeromonas wound infections associated with outdoor.
Isolate nm14 also belonged to the same group, while nm35 was identified as atypicalaeromonas species. The risk of the infected person passing the infection on to others is fairly low as long as they wash their hands properly. Aeromonas species are associated with gastroenteritis and with wound infections, particularly wounds incurred in outdoor settings. Studying the seasonal prevalence of aeromonas hydrophila in naturally collected and.
It can survive in a wide range of aquatic environments and it can also survive as a pathogen in an invertebrate or vertebrate host. Aeromonas definition of aeromonas by medical dictionary. Aeromonas hydrophila can exist either as as a freeliving aquatic habitant or inside of its host as a parasite to a variety of vertebrates including humans, fish, frogs, and crustaceans. Prevalence of aeromonas hydrophila infection in wild and. In recent years, aeromonas species have been recognized with increasing frequency as a cause of gastroenteritis in children and adults. Aeromonas hydrophila oreochromis niloticus aerolysin gene histopathological introduction species of fish and shellfish, feral as well as farmed in bacterial diseases in cultured fish are considered the the fish farming industry in egypt as well as in other main problem to aquaculture system in egypt. Pdf dynamics of aeromonas species isolated from wastewater. Characterization of waterborne aeromonas species for their. While it is still able to survive, it does not thrive under very extreme conditions such as salinity, temperature, and pollution. About 85% of gastrointestinal disorders in humans are attributed to aeromonas hydrophila, aeromonas caviae and aeromonas veronii biovar sobria. Gastrointestinal infections of aeromonas species are generally considered waterborne.
The infection required systemic antibiotic therapy. Aeromonas species cause a wide spectrum of disease syndromes among warm and coldblooded animals, including fish, reptiles, amphibians, mammals, and humans. Aeromonas a genus of gramnegative, facultatively anaerobic, nonsporeforming bacilli, which have been isolated from various foods, including dairy products, meats and vegetables. Most motile strains produce a single polar flagellum, while peritrichous or lateral flagella may be formed on solid media in some species. Also found in untreated and chlorinated drinking water, raw food and raw milk 2, 3. It is thought that people most often swallow the bacteria by drinking contaminated water handling contaminated fish or water and not washing their hands properly afterwards 2. Aeromonas can also cause gastroenteritis travellers diarrhoea, meningitis and peritonitis. Characterization of aeromonas species isolated from an estuarine. 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, softtissue, muscle infections, septicemia, and skin diseases. Limited studies were carried out in egypt regarding the seasonal prevalence of aeromonas hydrophila infection in wild and cultured o.
Aeromonas species are ubiquitous bacteria in terrestrial and aquatic milieus. Of the 67 isolates of aeromonas, 43 were identified as a. Of these, at least 104 were subsequently confirmed to be independent isolates. Aeromonas is a very rare cause of bacterial skin and soft tissue infection. Some of the members are associated to infections in humans, fish and. Organismsofthis genusaregramnegative, facultative anaerobes, motile with polar flagella. The genus has undergone a number of nomenclatural revisions in recent years and there are now 30 recognized species in the genus aeromonas. Antibiotic susceptibility patterns of aeromonas species. Aeromonas, plesiomonas and vibrio species veterian key. Aeromonas isolates from human diarrheic stool and groundwater. Aeromonas fact sheet hastings borough council elections. A total of 282 aeromonas pure cultures were isolated from both urban and rural playa lakes in the vicinity of lubbock, texas, and several rivers in west texas and new mexico.
Aeromonas biliary tract infections tend to occur in patients with biliary tract obstruction or stasis due to hepatobiliary cancer or stones. Aeromonas spp may contaminate skin wounds and cause intestinal and extraintestinal infections, including meningitis and sepsis in immunocompromised hosts. Occurrence of potential pathogenic aeromonas species in. A bacterial genus in the family vibrionaceae comprising oxidasepositive, facultatively anaerobic, monotrichously flagellated gramnegative rods. Aeromonas hydrophila infection associated with the use of. On the other hand, aeromonas, are environmental bacteria that are detected very few studies have reported identification at the in numerous gastrointestinal infections. Aeromonas strains capable of gastrointestinal infections in humans. Pdf characterization of aeromonas species isolated from. Phenotypic and genetic diversity of aeromonas species. Aeromonas strains were shown to be less sensitive to trimethoprimsulfamethoxazole, with 21 55% of the strains showing resistance to this antimicrobial. It is observed that the major cause of gastrointestinal infections by aeromonas species 3,4 is because of ingesting infected water 6,7.
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