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