Pathogen Safety Data Sheets: Infectious Substances – Aeromonas hydrophila

PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES

SECTION I - INFECTIOUS AGENT

NAME: Aeromonas hydrophila

SYNONYM OR CROSS REFERENCE: Septicemia, Gastroenteritis ^{Footnote 1}.

CHARACTERISTICS: A. hydrophila are Gram-negative, rod-shaped facultative anaerobes ^{Footnote 2}, ranging in size from 0.3-1.0 µm wide by 1.0-3.5 µm long ^{Footnote 1}. They are motile by a single polar flagellum ^{Footnote 1}. The bacteria can produce heat-labile enterotoxins, which can be associated with haemolysin and cytotoxin production ^{Footnote 3}.

SECTION II - HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: Infection with Aeromonas hydrophila can result in gastrointestinal or non-gastrointestinal complications. Symptoms of gastrointestinal infection range from watery diarrhea to dysenteric or bloody diarrhea. Chronic infection is also possible ^{Footnote 1}. Non-gastrointestinal complications that may arise subsequent to A. hydrophila infection include hemolytic syndrome and kidney disease, cellulitis, wound and soft-tissue infection, meningitis, bacteremia and septicemia ^{Footnote 4, Footnote 5}, ocular infections, pneumonia and respiratory tract infections ^{Footnote 6}, urinary tract infection in neonates ^{Footnote 7}, osteomyelitis, peritonitis and acute cholecystitis. Severe infection can result from non resolved intermittent diarrhea, which can occur months after the initial infection ^{Footnote 1, Footnote 2, Footnote 8}. A. hydrophila can cause disease in aquatic animals, such as red leg disease in frogs which is caused by endotoxin and haemolysin produced by the bacteria and can be fatal ^{Footnote 8, Footnote 9}.

EPIDEMIOLOGY: Worldwide – Aeromonas spp. are inhabitants of aquatic ecosystems and are found in most parts of the world ^{Footnote 1}. Although the role of Aeromonas hydrophila as a causative agent of human disease is controversial, some estimated that they may cause 13 % of gastroenteritis cases in United States ^{Footnote 10}. Some jurisdictions may not identify these organisms as pathogens.

Aeromonas spp. are commonly found in ground water; drinking water at treatment plants, distribution systems, and reservoirs; and in clean and polluted lakes and rivers ^{Footnote 1}. The bacteria are found in about 1% - 27 % of drinking water ^{Footnote 11} Aeromonas hydrophila can be found in fresh produce, meat, and dairy products. The risk of infection from oral ingestion of Aeromonas spp. is 7.3/billion for low exposure. Aeromonas spp. can also be found in soil.

HOST RANGE: Human, animals, birds, fish, and cold-blooded marine and freshwater reptiles ^{Footnote 1, Footnote 12, Footnote 13}.

INFECTIOUS DOSE: The infectious dose for humans and animals is greater than 10 ¹⁰ organisms ^{Footnote 11}.

MODE OF TRANSMISSION: Infection is spread via fecal-oral transmission during direct ingestion or drinking of contaminated water or foods ^{Footnote 1, Footnote 11, Footnote 14}. Infection can also be transmitted by eating contaminated meat, dairy, shrimp, or fish ^{Footnote 1}.

INCUBATION PERIOD: The reported incubation period for Aeromonas-associated diarrhea is 1 to 2 days ^{Footnote 15}. Aeromonas' infections contracted via recreational sporting activities, such as swimming occur as early as 24h post exposure ^{Footnote 15}. Cellulitis is the most frequent soft tissue infection and is usually accompanied by systemic signs developing within 8 to 48 h ^{Footnote 17}. The length of time from initial A. hydrophila infection to bacteremia ranges from 1 to 38 days ^{Footnote 16}.

COMMUNICABILITY: It can be transferred from human-to-human by contact with infected wounds, feces or blood ^{Footnote 18}. The pathogen can also be transferred during sports; especially when played in muddy environments involving transfer of infected soil.

SECTION III - DISSEMINATION

RESERVOIR: Free living, water is the main reservoir ^{Footnote 1}. It can also be found in mud, water, fresh produce, meat (beef, poultry, pork, fish, shellfish, and shrimp) and dairy products ^{Footnote 18}.

ZOONOSIS: None.

VECTORS: None.

SECTION IV - STABILITY AND VIABILITY

DRUG SUSCEPTIBILTIY: Sensitivity has been confirmed for fluoroquinolones (ciproflaxin) ^{Footnote 19}, aminoglycosides (except streptomycin), tetracycline ^{Footnote 20}, chloramphenicol ^{Footnote 21}, carbapenems ^{Footnote 22}, polymyxin, streptomycin, gentamicin ^{Footnote 23}, and trimethoprim-sulfamethoxazole.

DRUG RESISTANCE: Almost all Aeromonas spp. are resistant to penicillin, ampicillin, amoxicillin, ticarcillin, carbenicillin, and cephalothin ^{Footnote 21-Footnote 23}.

SUSCEPTIBILITY TO DISINFECTANTS: Susceptibility has been shown for 1% sodium hypochlorite, 2% glutaraldehyde, 70% ethanol, iodines, phenolics, and formaldehyde ^{Footnote 24}. It is also sensitive to silver in water ^{Footnote 25} and free chlorine ^{Footnote 26}.

PHYSCIAL INACTIVATION: Exposure to temperatures of 62 ^oC or greater for more that a few minutes is lethal to A. hydrophila. The bacteria can be inactivated by moist heat (121°C for 15 min - 30 min) and dry heat (160-170°C for 1-2 hours) ^{Footnote 27-Footnote 29}. The bacteria can also be inactivated by ultrasonic waves delivered under high pressure (200 KPa) and elevated temperatures (40 °C) ^{Footnote 29}. Simultaneous sonication at temperature higher than 70°C and 0.5 MPa is also effective ^{Footnote 30}.

SURVIVAL OUTSIDE HOST: Aeromonas hydrophila can survive in large volumes of open water, ground water, soil, as well as polluted lakes and rivers ^{Footnote 1}.

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. The bacteria can be detected by PCR ^{Footnote 10}. Aeromonas spp. samples can be isolated and confirmed on ampicillin dextrin agar forming yellow colour colonies ^{Footnote 31}. Confirmation by laboratory tests can be performed by oxidase test (positive), triple sugar iron agar (glucose fermenting), or Biolog detection methods ^{Footnote 1, Footnote 31}.

FIRST AID TREATMENT: Administration of antibiotics such as ciprofloxacin, co-trimoxazole, Gentamicin, or Amikacin ^{Footnote 1}. Intravenous fluid replacement in combination with oral antibiotics is effective in lessening infection symptoms ^{Footnote 32}.

IMMUNIZATION: None.

PROPHYLAXIS: None.

SECTION VI - LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: None reported to date.

SOURCES/SPECIMENS: The bacteria have been isolated from feces, sputum, urine, bile, pus, surgical wounds, medicinal leeches, normal flora, spleen, pleural fluid, placenta, skin lesion, throat, gall bladder, hospital water supplies, dialysis fluids, and blood plasma products ^{Footnote 14, Footnote 33, Footnote 34}.

PRIMARY HAZARD: Ingestion, accidental inoculation, direct contact with contaminated areas ^{Footnote 11, Footnote 18}.

SPECIAL HAZARDS: A. hydrophila is found in reptiles ^{Footnote 13} and aquatic animals ^{Footnote 1}, thus it can be a potential hazard when working with these animals in a laboratory environment.

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 2 ^{Footnote 35}.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures ^{Footnote 36}.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes ^{Footnote 36}.

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities ^{Footnote 36}.

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up ^{Footnote 36}.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration ^{Footnote 36}.

STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labeled ^{Footnote 36}.

SECTION IX - REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: December 2011

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Public Health Agency of Canada, 2011
Canada