Bacteri Aeromonas Sp.

By. Fahry Bima 23.

ETIOLOGI
Aeromonas hydrophila merupakan bakteri distribusinya luas. Bakteri ini dapat di temukan pada air tawar trpulusi maupun pada air laut yang kadar garamnya tinggi. Selain iut bakteri ini juga ditemukan pada intestinum ikan yang sehat.
m).Bakteri ini termsuk bakteri gram negatif, motil dan berbentuk batang (0,3-1,0 x 1,0-3,5

A. hydrophila mungkin paling sering menyebabkan wabah pada ikan yang diternakan maupun ikan yang hidup bebas pada air tawar. Penyakit akibat bakteri ini biasanya di asosiasikan dengan penyakit bakterial hemoragik septikemia pada ikan (dikenal sebagai aeromonad septicemia atau red pest ) yang mengalami stres karena beebagai sebab. Ikan dapat tertular penyakit inisetiap saat, walaupun biasanya sering terjadi pada saat musim panas dimana temperatur air meningkat dan ikan mengalami stress karena pergantian musim dari musiom panas ke mujsim dingin. Selain itu hal ini juga dapat terjadi akibat lingkungan yang jelek.


PERUBAHAN MAKROSKOPIS
Ikan yang terinfeksi biasanya dalam keadaan stress karena beberapa faktor dan menunjukan warna kulit yang gelap dengan hemoragik ireguler yang luas pada permukaan tubuh dan pangkal sirip. Selain itu ikan juga menunjukan gejala asites. Hemoragik pada permukaan kulit dapat mengalami ulserasi dan melanjud menjadi bentukan shallow necrotik lesions. Pada saat nekropsi organ terlihat mengalami kongesti dengan hemoragik pada organ dalam. Jika dilakukan irisan pada ginjal dan limpha yang membekak biasanya akan keluar cairan kental yang dari organ tersebut.

PERUBAHAN MIKROSKOPIS
Ginjal dan limpha mengalami atrofi dan selnya juga mengalami nekrosis. Membrana mukosa intestinal biasanya mengalami nekrosis dan sloughed menuju lumen. Nekrosis fokal ditemukan pad otot jantung, hepar, gonad dan pancreas. Lesi pada kulit diawali dengan munculnya edema pada dermis dan hiperemia dari stratum retikulare. Hal ini memicu terjadinya spongisis dan ulserasi dari epidermis yang diikuti dengan hemoragik nekrosis yang ekstensif menuju lapisan muskulus bagian bawah.

Klasifikasi Aeromonas hydrophila
Pada mulanya Aeromonas hydrophila dikenal dengan nama Bacilus hydrophilus fuscus. Bakteri ini pertama kali diisolasi dari kelenjar pertahanan katak yang mengalami perdarahan septisemia. Pada tahun 1936, Kluiver dan Van Niel telah mengelompokkan genus Aeromonas. Selanjutnya pada tahun 1984, Popoff telah memasukan genus Aeromonas ke dalam famili Vibrionaceae (Anonimous 2004a diacu dalam Yudha 2005). Mikroorganisme ini secara normal dapat ditemukan dalam lingkungan perairan (Blair et al. 1999 diacu dalam Robinson et al. 2000). Aeromonas hydrophila diisolasi dari manusia dan binatang sampai dengan tahun 1950. Bakteri ini memiliki nama sinonim A. formicans dan A. liquefaciens (Sismeiro et al. 1998).

Berikut adalah klasifikasi Aeromonas hydrophila (Holt et. al. 1998):
Filum : Protophyta
Kelas : Schizomycetes
Ordo : Pseudanonadeles
Family : Vibrionaceae
Genus : Aeromonas
Spesies : Aeromonas hydrophila

Karakteristik Aeromonas hydrophila
Aeromonas hydrophila merupakan bakteri heterotrophic unicellular, tergolong protista prokariot yang dicirikan dengan adanya membran yang memisahkan inti dengan sitoplasma. Bakteri ini biasanya berukuran 0,7-1,8 x 1,0-1,5 µm dan bergerak menggunakan sebuah polar flagel (Kabata 1985). Hal ini diperkuat oleh Krieg dan Holt (1984) yang menyatakan bahwa Aeromonas hydrophila bersifat motil dengan flagela tunggal di salah satu ujungnya. Bakteri ini berbentuk batang sampai dengan kokus dengan ujung membulat, fakultatif anaerob, dan bersifat mesofilik dengan suhu optimum 20 - 30 ºC (Kabata 1985).

Aeromonas hydrophila bersifat gram negatif, oksidasi positif dan katalase positif (Krieg dan Holt 1984). Bakteri ini juga mampu memfermentasikan beberapa gula seperti glukosa, fruktosa, maltosa, dan trehalosa. Hasil fermentasi dapat berupa senyawa asam atau senyawa asam dengan gas. Pada nutrient agar, setelah 24 jam dapat diamati koloni bakteri dengan diameter 1-3 mm yang berbentuk cembung, halus dan terang (Isohood dan Drake 2002).

Aeromonas hydrophila merupakan bakteri yang secara normal ditemukan dalam air tawar. Infeksi Aeromonas hydrophila dapat terjadi akibat perubahan kondisi lingkungan, stress, perubahan temperatur, air yang terkontaminasi dan ketika host tersebut telah terinfeksi oleh virus, bakteri atau parasit lainnya (infeksi sekunder), oleh kerena itu bakteri ini disebut dengan bakteri yang bersifat patogen oportunistik (Dooley et al. 1985).

Bakteri ini dapat bertahan dalam lingkungan aerob maupun anaerob dan dapat mencerna material-material seperti gelatin dan hemoglobin. Aeromonas hydrophila resisten terhadap chlorine serta suhu yang dingin (faktanya Aeromonas hydrophila dapat bertahan dalam temperatur rendah ± 4 ºC), tetapi setidaknya hanya dalam waktu 1 bulan (Krieg dan Holt 1984). Austin (1993) menambahkan bahwa sebagian besar isolat Aeromonas hydrophila mampu tumbuh dan berkembangbiak pada suhu 37 oC dan tetap motil pada suhu tersebut. Disamping itu, bakteri Aeromanas hydrophila mampu tumbuh pada kisaran pH 4,7-11,0 (Cipriano et al. 1984 diacu dalam Fauci 2001).

Aeromanas hydrophila menyebabkan penyakit Motile Aeromonas Septicemia (MAS) atau penyakit bercak merah. Bakteri ini menyerang berbagai jenis ikan air tawar seperti lele dumbo, (Clarius glariepinus), ikan mas (Cyprinus carpio), gurami (Osphronemus gouramy) dan udang galah (Macrobracium rusenbergil) dan dapat menimbulkan wabah penyakit dengan tingkat kematian tinggi (80-100%) dalam waktu 1-2 minggu.
Pengendalian bakteri ini sulit karena memiliki banyak strain dan selalu ada di air serta dapat menjadi resisten terhadap obat-obatan (Kamiso dan Triyanto 1993).

Patogenesa Penyakit
Menurut Botterelli dan Ossiprandi 1999 yang diacu dalam Hidayat 2006, sebagaimana halnya bakteri enteropatogenik, terdapat dua mekanisme patogenesa infeksi bakteri Aeromonas hydrophila, yaitu:

1 Tissue adherence. Mekanisme ini diperantarai oleh S-Layer. S-Layer membantu penempelan dan kolonisasi bakteri pada mukosa usus. Proses ini juga dibantu oleh struktur filamentous (fimbriae) atau membranous (adhesins) yang memiliki aktivitas hemagglutinasi, terutama ditemukan pada strain mesofilik.
2 Toxin production. Toksin Aeromonas dapat diklasifikasikan menjadi endotoksin dan eksotoksin. Cytotoxins dan enterotoxins (termasuk aktivitas haemolytic) merupakan yang paling penting dalam patogenitas.

Patogenitas Aeromonas hydrophila
Aeromonas hydrophila yang patogen, diduga memproduksi faktor-faktor eksotoksin dan endotoksin, yang sangat berpengaruh pada patogenitas bakteri ini. Eksotoksin merupakan komponen protein terlarut, yang disekresikan oleh bakteri hidup pada fase pertumbuhan eksponensial. Produksi toksin ini biasanya spesifik pada beberapa spesies bakteri tertentu baik Gram positif maupun Gram negatif, yang menyebabkan terjadinya penyakit terkait dengan toksin tersebut. Endotoksin adalah toksin yang merupakan bagian integral dari dinding sel bakteri Gram negatif. Aktivitas biologis dari endotoksin dihubungkan dengan keberadaan lipopolisakarida (LPS). LPS merupakan komponen penyusun permukaan dari membran terluar (outer membrane) bakteri Gram negatif (Syamsir 2008).

Eksotoksin yang diproduksi oleh Aeromonas hydrophila meliputi hemolisin, protease, elastase, lipase, sitotoksin, enterotoksin, gelatinase, kaseinase, lecithinase dan leucocidin. Hemolisin merupakan enzim yang mampu melisiskan sel-sel darah merah dan membebaskan hemoglobinnya. Protease adalah enzim proteolitik yang berfungsi untuk melawan pertahanan tubuh inang untuk berkembangnya penyakit dan mengambil persediaan nutrient inang untuk berkembangbiak (Angka 2001). Aeromonas hydrophila dapat memanfaatkan albumin, kasein, fibrinogen, dan gelatin sebagai substrat protein. Dengan demikian dapat disimpulkan bahwa bakteri ini bersifat proteolotik (Shotts et al. 1985), sehingga berpotensi besar sebagai patogen ikan. Adanya enzim proteolitik akan merusak dinding intenstin, sehingga terjadi penebalan dinding, udem dan semi transparan (Munro 1982). Ketika Aeromonas hydrophila masuk ke dalam tubuh inang, maka toksin yang dihasilkan akan menyebar melalui aliran darah menuju organ. Enterotoksin merupakan suatu toksin ekstraseluler bakteri yang khususnya menyerang saluran gastrointestinal. Lechitinase adalah enzim yang menghancurkan berbagai sel jaringan dan terutama aktif melisiskan sel-sel darah merah, sedangkan leucocidin adalah enzim yang dapat membunuh sel-sel darah putih (Pleczar & Chan 1988). Hirono dan Aoki (1991) menambahkan bahwa Aeromonas hydrophila dapat memproduksi toksin ekstrasellular acetylcholinesterase, phospholipids, acyltransferase dan protease.

Bakteri Aeromonas hydrophila memiliki struktur dinding sel berupa Lipopolisakarida (LPS) yang dikenal sebagai endotoksin. Menurut Syamsir (2008), LPS dapat menyebabkan peradangan, demam, penurunan kadar besi, dan pembekuan darah. Angka (2001) menambahkan bahwa LPS dapat menyebabkan shock pada inang. Endotoksin akan dilepaskan ke lingkungan hanya apabila bakteri tersebut mati dan mengalami lisis.
Disamping mampu memproduksi eksotoksin dan endotoksin sebagai faktor virulensi, Aeromonas hydrophila patogen juga memiliki kemampuan untuk menempel pada sel tubuh ikan melalui aktifitas adhesins (Trust et al. diacu dalam Austin & Austin 1993). Adhesins ini bersifat sangat selektif, hanya mampu mengenali rantai polimer D-mannosa dan L-sucosa yang terletak pada permukaan sel eukariot. Dengan menempelnya Aeromonas hydrophila pada permukaan sel inang, kemungkinan besar sel inang tersebut akan terinfeksi (Austin & Austin 1993).

Baru-baru ini diketahui bahwa bakteri Aeromonas hydrophila yang motil dapat berpotensi menyebabkan infeksi saluran gastrointestinal pada manusia. Penelitian membuktikan bahwa beberapa strain Aeromonas hydrophila dapat menyebabkan kasus enteropathogenic, khususnya pada anak-anak, orang tua dan penderita immunocompromised (rusaknya sistem imun akibat infeksi patogen). Beberapa gejala diare akibat Aeromonas hydrophila penyebab gastroenteritis berkaitan erat dengan diproduksinya enterotoksin oleh Aeromonas hydrophila (Trower et al. 2000).

DAFTAR PUSTAKA.

Andrews, C., A. Exell and N. Carrington. 1988. The Intervet Manual of Fish Health.
Salamander Books Ltd. London.

Meyer, F.P. 1964. Field treatment of Aeromonas liquefaciens infections in golden shiners. Prog. Fish-Cult. 26(1): 33-35.

Post, G. 1983. Textbook of Fish Health.TFH Publication, Inc. Ltd.

Sarig, S. 1971. Diseases of Warmwater Fishes. TFH Publ., Neptune City, New Jersey.

Snieszko, S.F. 1973. The effect of environmental stress on outbreak of infection diseases of fishes. J. Fish. Biol. (6) : 197 208.

Supriyadi, H. dan P. Taufik. 1983. Penelitian pendahuluan immunisasi ikan dengan cara vaksinasi. Bull. Pen. PD .4 (1): 34 36.

Supriyadi, H. 1986. The susceptibility of various fish species to infection by the bacterium Aeromonas hydrophila. p. 241-242. In J.L. Maclean, L.B.Dizon and L.V. Hosillos (eds) The First Asian Fisheries Forum . Asian Fisheries Society. Manila. Philippines.

Supriyadi, H and A. Rukyani. 1990. The use of antibiotics and drugs for treatment of bacterial disease on fish and shrimp in Indonesia. In. Disease in Asian Aquaculture I. M. Shariff, R.P. Subashinghe and J.R. Arthur (eds), p. 515-517. Fish Health Section, Asian Fisheries Society, Manila, Philippines.

Supriyadi, H and M. Shariff. 1995. Evaluation of the immune response and protection confered in walking catfish, Clarias batrachus, administered inactivated Aeromonas hydrophila bacterin by immersion. In Diseases in Asian Aquaculture II. M. Shariff, J.R. Arthur and Subasinghe (eds) p. 405-412. Fish Health Section, Asian Fisheries Society, Manila. Philippines.

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Aeromonas hydrophila In Fish and In Humans

By. Fahry Bima 22.

Background
Aeromonads are ubiquitous, oxidase-positive, facultatively anaerobic, glucose-fermenting, Gram-negative bacteria that are native to aquatic environments (Hazen et al., 1978). They have been found in brackish, fresh, estuarine, marine, chlorinated and unchlorinated water supplies worldwide, with highest numbers obtained in the warmer months (Van der Kooj et al., 1988; Kaper et al., 1981; Hazen et al., 1978). Aeromonads have been isolated from diseased cold- and warm-blooded animals for over 100 years, and from humans since the early 1950s (Mathewson and Dupont, 1992).

Scanning electron micrograph of Aeromonas hydrophila attached to a human intestinal epithelial cell line (photo courtesy of Northwest Fisheries Science Center, NOAA).
Aeromonas hydrophila
• motile rod-shaped bacterium
• 0.3-1.0 um in diameter and 1.0-3.5 um in length
• no spore stage; usually unencapsulated
• optimum growth at 28 C, but growth observed at extremes (4 C and 37 C)

The ubiquitous nature of Aeromonas species in aquatic environments provides ample opportunity for animals, particularly fish and amphibians, to come into contact with, and to ingest organisms. Such contact may lead to infection which, depending on the species and the virulence of the strains encountered, may have life-threatening consequences.

Aeromonas hydrophila has been recovered from a wide-range of freshwater fish species worldwide, and occasionally from marine fish—e.g. ulcer disease of cod (Larsen and Jensen, 1977). However, conflicting views have been expressed over the precise role of A. hydrophila as a fish pathogen. Some researchers contend that the organism is only a secondary invader of previously weakened hosts, while others believe that A. hydrophila is a primary pathogen of freshwater fish (Eurell et al., 1978).
The Disease (in Fish)

A. hydrophila has been associated with several disease conditions in fish, including tail rot, fin rot, and haemorrahagic septicaemias. Haemorrahagic septicaemia is characterized by the presence of small surface lesions, often leading to sloughing off of the scales, haemorrhaging in the gills and anus, ulcers, abscesses, exophthalmia (bulging eyes), and abdominal swelling (dropsy)--often seen in European carp culture. Internally, there may be the presence of ascitic fluid in the peritoneal cavity, anaemia, and swelling of the kidney and liver (Miyazaki and Kaige, 1985). Another condition caused by A. hydrophila, known as red-fin disease, is characterized by the presence of surface haemorrhages and scale erosion.

Eel (Anguilla japonica) with red-fin disease caused by Aeromonas hydrophila (photo courtesy of Dr. Teruo Miyazaki). During the 1960s, outbreaks of red-fin disease, caused by A. hydrophila, occurred frequently in cultured eels in Japan (Hoshina, 1962; Egusa, 1978).

The etiologic agent is transmitted horizontally (between animals other than parents and offspring) but not vertically (from parent to offspring). The bacteria multiply inside the intestine, causing a haemorrhagic mucuous-desquamative catarrh (excessive mucous secretion). Toxic metabolites of A. hydrophila are absorbed from the intestine and induce poisoning. Capillary haemorrhage occurs in the dermis of fins and trunk and in the submucosa of the stomach. Hepatic cells and epithelia of renal tubules show degeneration. Glomeruli are destroyed and the tissue becomes haemorrhagic, with exudates of serum and fibrin (Miyazaki and Jo, 1985; Miyazaki and Kage, 1985).

Aeromonas species produce many products that may be toxic to other cells. Some are released from viable cells in soluble form. Others may remain associated with the cell surface, and still others may be released upon cell death. Three of the extracellular proteins of Aeromonas species—that have been implicated in pathogenicity—have been cloned, sequenced, and characterized biochemically. These are aerolysin, GCAT (glycerophospholipid:cholesterol acyltransferase), and a serine protease (Howard and Buckley, 1986; Buckley et al., 1991; Rodriguez et al, 1992)
Outbreaks of disease are usually associated with a change in environmental conditions. Stressors, including overcrowding, high temperature, a sudden change of temperature, rough handling, transfer of fish, low dissolved oxygen, poor nutritional status, and fungul or parasitic infection, contribute to physiological changes and heighten susceptibility to infection.

Control and Treatment
Prevention in Aquaculture (adpated from Warren, 1991)
1.Avoid hatchery to hatchery transfers of fish. Fish gradually develop resistance to local strains of bacteria but may carry virulent organisms to another hatchery when transferred.
2.Provide optimal environmental conditions for the species being reared, paying special attention to the maintenance of oxygen levels and the gentle handling of fish.
3.Prophylactic treatments are helpful when sorting, handling, or moving broodstock. Intraperitoneal injections of 10–30 mg per pound of body weight of aqueous chloramphenicol has reduced post-handling losses by 80–90 percent in Europe.
4.Antibiotics or disinfectants should be added to the water as a prophylactic measure when fish are transported in tank trucks or plastic bags. Acriflavin at 2–4 ppm has been used in routine fish transportation operations.

Therapy
Chemotherapeutic agents are used for the treatment of A. hydrophila in fish farms. Isolates of A. hydrophila in fish have been found to be sensitive to chloramphenicol, florfenicol, tetracycline, sulphonamide, nitrofuran derivatives, and pyrodinecarboxylic acids (Aoki and Egusa, 1971; Endo et al., 1973; Katae et al. 1979; Fukui et al. 1987). In hatchery operations, terramycin has been effective when incorporated into pelleted fish feed and fed at 3.5 grams of active drug per 100 pounds of fish per day for 10 days (Warren, 1991). [Note: Antibacterial therapy will provide only short-term relief if adverse environmental conditions such as high water temperatures, low water flows, low oxygen levels, or crowding are not promptly corrected].

The Disease (in Humans)
Bacteraemia (bacteria in the blood) is the most common pathogenic manifestation of Aeromonas in humans. Mild symptoms include fever and chills, but patients who become septic (overwhelming bacterial infection) with Aeromonas often exhibit abdominal pain, nausea, vomiting, and diarrhea.

Reports of Aeromonas wound infections have appeared increasingly in the literature. Unlike gastroenteritis, these infections can have fatal or serious debilitating outcomes, such as amputations. Aeromonas wounds fall into three categories, listed in order of increasing severity of damage caused: cellulitis, myonecrosis, and ecthyma gangrenosum.

Cellulitis, the most frequently encountered Aeromonas wound infection, is an acute inflammation of subcutaneous tissue characterized by redness and induration that may arise from injury or secondary to sepsis (Musher, 1980). Myonecrosis and ecthyma, the two less commonly seen types of Aeromonas infections, are typically found in patients that are immunocompromised. Myonecrosis, or bullous lesions, is characterized by the liquefaction of muscles with blackening of the tissue which may be gangrenous with gas formation. These patients require agressive antimicrobial therapy and debridement; those individuals that fail to respond to these measures may require amputation (Haburchak, 1996). The third type, ecthyma gangrenosum, is a cutaneous necrotic or gangrenous pustule that occurs secondary to sepsis. Lesions have an erythematous border surrounding a vesicle which can progress to necrosis of the soft tissue within 24 h. This type of infection is usually fatal (Musher, 1980).

Outcomes such as these serve as a sobering reminder to properly attend to wounds with clean water and antiseptics. Never wash a wound with lake or river water!
A. hydrophila infections require prompt attention at the first sign of onset. Most infections are treated with fluoroquinolones. Alternative agents include aztreonam, trimethoprim-sulfamethoxazole, third-generation cephalosporins, and/or aminoglycosides (Mani et al., 1995).

Reff From :
John Hayes
MB592 - Diseases of Fish
Spring 2000 Term Project
Oregon State University

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Charakteristic of Aeromonas hydrophila

By. Fahry Bima21

Charakteristic of Aeromonas hydrophila

1. Name of the Organism:
Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria & (Aeromonas veronii?)

Aeromonas hydrophila is a species of bacterium that is present in all freshwater environments and in brackish water. Some strains of A. hydrophila are capable of causing illness in fish and amphibians as well as in humans who may acquire infections through open wounds or by ingestion of a sufficient number of the organisms in food or water.
Not as much is known about the other Aeromonas spp., but they too are aquatic microorganisms and have been implicated in human disease.

2. Nature of Acute Disease:
A. hydrophila may cause gastroenteritis in healthy individuals or septicemia in individuals with impaired immune systems or various malignancies.
A. caviae and A. sobria also may cause enteritis in anyone or septicemia in immunocompromised persons or those with malignancies.



3. Nature of Disease:
At the present time, there is controversy as to whether A. hydrophila is a cause of human gastroenteritis. Although the organism possesses several attributes which could make it pathogenic for humans, volunteer human feeding studies, even with enormous numbers of cells (i.e. 10^11), have failed to elicit human illness. Its presence in the stools of individuals with diarrhea, in the absence of other known enteric pathogens, suggests that it has some role in disease.

Likewise, A. caviae and A. sobria are considered by many as "putative pathogens," associated with diarrheal disease, but as of yet they are unproven causative agents.
Two distinct types of gastroenteritis have been associated with A. hydrophila: a cholera-like illness with a watery (rice and water) diarrhea and a dysenteric illness characterized by loose stools containing blood and mucus. The infectious dose of this organism is unknown, but SCUBA divers who have ingested small amounts of water have become ill, and A. hydrophila has isolated from their stools.
A general infection in which the organisms spread throughout the body has been observed in individuals with underlying illness (septicemia).

4. Diagnosis of Human Illness:
A. hydrophila can be cultured from stools or from blood by plating the organisms on an agar medium containing sheep blood and the antibiotic ampicillin. Ampicillin prevents the growth of most competing microorganisms. The species identification is confirmed by a series of biochemical tests. The ability of the organism to produce the enterotoxins believed to cause the gastrointestinal symptoms can be confirmed by tissue culture assays.

5. Associated Foods:
A. hydrophila has frequently been found in fish and shellfish. It has also been found in market samples of red meats (beef, pork, lamb) and poultry. Since little is known about the virulence mechanisms of A. hydrophila, it is presumed that not all strains are pathogenic, given the ubiquity of the organism.

6. Relative Frequency of Disease:
The relative frequency of A. hydrophila disease in the U.S. is unknown since efforts to ascertain its true incidence have only recently been attempted. Most cases have been sporadic rather than associated with large outbreaks, but increased reports have been noted from several clinical centers.

7. Course of Disease and Complications:
On rare occasions the dysentery-like syndrome is severe and may last for several weeks.
A. hydrophila may spread throughout the body and cause a general infection in persons with impaired immune systems. Those at risk are individuals suffering from leukemia, carcinoma, and cirrhosis and those treated with immunosuppressive drugs or who are undergoing cancer chemotherapy.

8. Target Populations:
A. hydrophila can be recovered from most foods by direct plating onto a solid medium containing starch as the sole carbohydrate source and ampicillin to retard the growth of most competing microorganisms.

9. Food Analysis:
All people are believed to be susceptible to gastroenteritis, although it is most frequently observed in very young children. People with impaired immune systems or underlying malignancy are susceptible to the more severe infections.

10. Selected Outbreaks:
Literature references can be found at the links below.
Most cases have been sporadic, rather than associated with large outbreaks.
For information on recent outbreaks see the Morbidity and Mortality Weekly Reports from CDC.

11. Education and Background Resources:
Literature references can be found at the links below.

Loci index for genome Aeromonas hydrophila
Available from the GenBank Taxonomy database, which contains the names of all organisms that are represented in the genetic databases with at least one nucleotide or protein sequence.

12. Molecular Structural Data:
None currently available.

Reff from :

CDC/MMWR
The CDC/MMWR link will provide a list of Morbidity and Mortality Weekly Reports at CDC relating to this organism or toxin. The date shown is the date the item was posted on the Web, not the date of the MMWR. The summary statement shown are the initial words of the overall document. The specific article of interest may be just one article or item within the overall report.
NIH/PubMed
The NIH/PubMed button at the top of the page will provide a list of research abstracts contained in the National Library of Medicine's MEDLINE database for this organism or toxin.
AGRICOLA
The AGRICOLA button will provide a list of research abstracts contained in the National Agricultural Library database for this organism or toxin.

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