MICROBIOLOGY OF WATERS
Àlex Mezquida LópezOliver Rodés
Miquel Salgot de MarçayUniversity of Barcelona
Spain
ORGANISMS IN WATER
Water bodies are the habitat for:
Macroorganisms (fish, macroinvertebrates, mammals, crocodiles, plants...)
Microorganisms (bacteria, virus, protozoa, microalgae…)
ORGANISMS IN WATER
• Microorganisms (not typical from water, e.g. from faecal origin) can survive in water but not develop there. It is a way for being transported to the host
• The few that survive have an increased “capacity for infection” or “high pathogenic power in reduced amounts”
• Virus cannot multiply in water bodies, but free, associated to bacteria, parasites and suspended solids can reach the consumer
• Types: Infections by (bacteria, viruses and parasites) PATHOGENSIntoxication (only bacterial by-products)Other (e.g. algal toxins)
IMMUNE SYSTEM
ACTIVATES
Basics of Microbiology: Illnesses
HOW THE PATHOGENS REACH THE CONSUMER (through WATER)
DRINKING
• Adhered to solid particles and sediments (e.g. clay)• Mobilized by water (kinetic energy)• Directly suspended in water
BY CONTACT
• Indirectly (e.g. clothes, irrigated food, etc.)• Contact with the skin or mucosae
BREATHING
• Aerosols
Once inside the body, there is an answer of the immune system (the human body counteracts)
FAGOCITOSIS (BACTERIA, VIRUSES…) by white blood cells (leucocytes)
White blood cell
Pseudopod Bacteria
POLLUTED WATER-RELATED ILLNESSES (biological origin)
Water-related health problems are caused by organisms (illnesses) or chemicals (usually called toxicity)
Organisms or derived:
• Existing in natural water:– Bacteria– Parasites– Virus– Some chemicals from biological origin
• The role of water: just transportation (water is innocent)
MICROBIOLOGICAL ANALYSIS OF WATER
• Directly (protozoa, worms, bacteria, viruses… )
• By using indicators (for bacteria and viruses)
• Indirectly: techniques detecting parts of the organisms
MICROBIOLOGICAL ANALYSIS OF WATER
• Indicators
“Water quality through the presence of pathogenic enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and
coliphages are normally used as indicators of water quality”
Then, it is not necessary to determine all pathogens that can appear in water (it refers to bacteria and viruses only/mainly)
Other organisms are analysed directly (protozoa…)
WATER MICROBIOLOGY
By size, bigger to smaller:
PARASITES
BACTERIA
VIRUS
PRIONS
Other (not by size): MOULD, YEASTS and ALGAE
GROWTH FACTORS OF MICROORGANISMSHow and why microorganisms grow or not out of the body
1. Temperature• Psicrophyll(e)s (2.5 – 20ºC) (a)• Mesophyll(e)s (3 – 45ºC)• Thermophyll(e)s (30 – 65ºC)
2. Oxygen• Anaerobic (Facultative and compulsory)• Microaerobic• Aerobic
3. Free water (water activity)
4. pH (Acidity)
SIZE OF BACTERIA
Bacteria over the tip of a needle1µm is the result of dividing 1 mm by 1,000
100µm 20µm 1µm
BACTERIA
Unicellular organisms from the Protista group. Single cells variable on size from 0.2 µm to 50 µm; average dimensions between 0.5 and 1 µm
1. Scheme 2. Escherichia coli in several division phases
BACTERIA MULTIPLICATION BY DIVISION
A
B
C
BACTERIA MULTIPLICATION
• Successive pictures of an Arthrobacter colony growth, from a single cell, in a 40 hours period
BACTERIAL GROWTH
USEFUL BACTERIA : BIFIDOBACTERIUM
Propionebacterium, helps to obtain Swiss cheese.
BACTERIAL GROWTH
CLOSTRIDIA
Inclusion body
Spore
CLOSTRIDIA
Clostridium tetani and C. perfringens
Enterococci spp
Indicators of faecal contamination by bacteria
Its presence indicates lack of hygiene, is a good indicator of faecal pollution
MICROORGANISM Enterococcus genera
Range of growing temperatures
• Growth between 10 and 45 ºC • Optimum: 37 - 41 ºC
Where is it found • Gastrointestinal tract and faeces of animals
Associated facilities • Water for leisure activities, swimming pools, theme parks with water • Water for human consumption, wastewater
Elimination • Adequate control on potable water treatment facilities with Pre-oxidation, coagulation, flocculation, settling, filtration over sand and with membranes, disinfection, activated carbon filters, etc. systems
Prevention methods • Periodical analytical controls
• Follow the standard procedures as indicated in rules, regulations and technical guidelines
• Use adequate and authorized techniques, mechanisms and products
Additional information • The Enterococcus genera has 12 species. It is characterized to be highly resistant, being tolerant to high salt concentrations (up to 6.5 % of NaCl in the environment) and to acids.
Enterococci
Escherichia coli
ILLNESS COLIBACILOSIS (only a few strains)
MICROORGANISM Escherichia coli
Range of growing temperatures
• Growth between 10 and 45 ºC • Optimum: 37 - 41 ºC
Where is it found • Gastrointestinal tract and faeces of all hot blooded animals and men
Associated facilities • Water for leisure activities, swimming pools, theme parks with water • Water for human consumption, wastewater
Elimination • Adequate control on potable water treatment facilities with Pre-oxidation, coagulation, flocculation, settling, filtration over sand and with membranes, disinfection, activated carbon filters, etc. systems
Prevention methods • Periodical analytical controls
• Follow the standard procedures as indicated in rules, regulations and technical guidelines
• Use adequate and authorized techniques, mechanisms and products
Additional information • Is the classical indicator of faecal contamination of water by bacteria
Escherichia coli
Legionella pneumophila
Infection by inhalationIs considered highly dangerous: In many countries has its own rules and regulations for control and analysis
ILLNESS LEGIONELLOSISMICROORGANISM Legionella pneumophilaRange of growing temperatures
• Variable between 20-45 ºC • Optimum: 35-40 ºC
Where is it found • Natural surface waters • Biofilms
Intracellular: amoeba and ciliated protozoa
• Water distribution networks, especially sanitary water
Associated facilities • Hot water networks• Cooling towers• Bathtubs, spa, hot water swimming pools, jacuzzi• Cold water networks• Sprinklers and ornamental fountains• Humidifying devices• Air conditioning condensers • Shower devices
Elimination • Adequate control on potable water treatment facilities with Pre-oxidation, coagulation, flocculation, settling, filtration over sand and with membranes, disinfection, activated carbon filters, etc. systems
Legionella pneumophila
Prevention methods • Periodical analytical controls • Follow the standard procedures as indicated in rules, regulations
and technical guidelines • Use adequate and authorized techniques, mechanisms and
products• Is difficult to eliminate in cooling towers and water distribution
networksAdditional information • This bacteria has found an adequate habitat in the water networks
manipulated by man where can be amplified and widely distributed. • More than 40 strains with more than 64 sero groups are described.• Biofilms in water networks are considered as reservoirs as well as
amoeba (in pipes, water tanks, cooling towers, water wearing devices like cleaning vehicles using water…)
Legionella pneumophila
PROTOZOA: GIARDIA LAMBLIA
WATER-RELATED PARASITESGIARDIA LAMBLIA
Cyst: is the infective and resistant form which will be present in food and water
Trophozoite: is the form living, eating and reproducing in the host body
Pathogenicity: is mainly due to its effects when being adhered and fixed to the gut epithelium, acting over the microvilliIts incubation period is from 1 to 3 weeks. Man is the only hostSymptomatology: Lasts for 2 to 6 weeks. Diarrhoea, belly distension and abdominal pain, anorexiaTo note: resists chlorination of water
OOCYSTS: CRYPTOSPORIDIUM
In water oocysts can be found, extremely resistant thanks to their protecting structures
Pathogenicity: 2-14 days Incubation, with symptoms up to 2 weeks in healthy personsFor immuno-depressed people can be deathlySymptomatology:Watery diarrhoea, also belly spasms, nausea, mild fever, dehydration and loss of Symptoms appear 4 to 6 days after infection
To note: resists chlorination of water
WATER-RELATED PARASITESCRYPTOSPORIDIUM PARVUM
Round worms: long, cylindrical and not-segmented body. Size from less than 1 mm to several cmCan cause haemorrhages, anaemia, paleness, loss of weight, diarrhoea syndrome, general feeling of discomfort, etc.
ÁSCARIS LUMBRICOIDES ANCYLOSTOMA DUODENALE TRICHURIS TRICHIURA
WATER-RELATED PARASITES:NEMATODES
Pathogenicity: Especially dangerous for pregnant women, the infection can be transmitted to the foetus, and also for immuno-depressed individuals. Man is and intermediary host being the definitive one the catSymptomatology:For healthy people the symptomatology is similar to the flueFor the foetus the consequences are malformations and heart, liver and brain affectationIn immuno-depressed individuals can cause deathly encephalitis
1. Sporulated oocysts: Is the form of resistance in the environment
2. Bradizoite:In the meat of infested mammalian: lambs, pigs and cows
3. Tachyzoite:In the organs of human body
WATER-RELATED PARASITESTOXOPLASMA GONDII
TOXOPLASMA GONDII
WORMS: NEMATODA
VIRUS
AIDS virusBacteriophage (model)
VIRUS
VIRAL FORMS
INFECTION: VIRUS “LYSIS CICLE”
• Fungi and yeasts
• Algae and its “by-products”
OTHER MICROORGANISMS IN WATER