Microorganisms can survive in water but water is not an adequate place for them to develop. Viruses cannot multiply in water but can be transmitted through water attached to bacteria, parasites, or suspended solids. Water bodies contain macroorganisms like fish as well as microorganisms like bacteria, viruses, protozoa, and algae. Pathogens in water can infect people through drinking, contact, or breathing contaminated water aerosols. Once inside the body, the immune system responds through processes like phagocytosis of bacteria and viruses.

1. MICROBIOLOGY OF WATERS
Àlex Mezquida López
Dr. Oliver Rodés Laboratory
Miquel Salgot de Marçay
University of Barcelona
Spain

2. ORGANISMS IN WATER
• Microorganisms (not typical of water, e.g. from faecal origin)
can survive there but water is not and adequate place to
develop. It is just a tool for transmission to the hosts.
• The few that survive have an increased “capacity for infection”
or high pathogenic power in reduced amounts”.
• Virus cannot multiply in water bodies, but associated to
bacteria, parasites and suspended solids can reach the
consumer.
Water bodies are the habitat for:
 Macroorganisms (fish, macroinvertebrates, mammals, crocodiles,
plants...)
 Microorganisms (bacteria, virus, protozoa, microalgae…)

3. • Types:
Infections (bacteria, viruses and parasites: PATHOGENS)
Intoxication (only bacteria)
Other (e.g. algal toxins)
IMMUNE SYSTEM
ACTIVATES
Basics of Microbiology: Illnesses

4. 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
CONTACT
• Indirectly (e.g. clothes, irrigated food, etc.)
• Contact with the skin or mucosae
BREATHING
• Aerosols

5. Once inside the body, there is an answer
of the immune system
FAGOCITOSIS (BACTERIA, VIRUSES…)
White blood cell
Pseodopod Bacteria

6. 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: transportation (water is innocent)

7. MICROBIOLOGICAL ANALYSIS OF WATER
• Directly (protozoa, worms… )
• By using indicators (for bacteria and viruses)

8. 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”
In this way it is not necessary to determine all pathogens that can appear in
water (it refers to bacteria and viruses only/mainly)

9. WATER MICROBIOLOGY
By size, bigger to smaller:
 PARASITES
 BACTERIA
 VIRUS
 PRIONS
Other (no by size): MOULD, YEASTS and ALGAE

10. GROWTH FACTORS OF MICROORGANISMS
1. Temperature
• Psicrophyll(e)s (2.5 – 20ºC) (a)
• Mesophyll(e)s (3 – 45ºC)
• Thermophyll(e)s (30 – 65ºC)
2. Oxigen
• Anaerobic (Facultative and compulsory)
• Microaerobic
• Aerobic
3. Free water (water
activity)
4. pH (Acidity)

11. SIZE OF BACTERIA
Bacteria over the tip of a needle
1µm is the result of dividing 1 mm by 1,000
100µm 20µm 1µm

12. BACTERIA
Unicellular organisms from the Protista group. Single cells variable on size from 0.2 µm to50 µm; average
dimensions between 05 and 1 µm.

13. 1. Scheme 2. Escherichia coli in several
division phases
BACTERIA MULTIPLICATION BY DIVISION
A
B
C

14. BACTERIA MULTIPLICATION

15. • Successive pictures of an
Arthrobacter colony
growth, from a single
cell, in a 40 hours period.
BACTERIAL GROWTH

16. Propionebacterium, helps to obtain Swiss cheese.
BACTERIAL GROWTH

17. USEFUL BACTERIA : BIFIDOBACTERIUM

18. CLOSTRIDIA
Inclusion body
Spore

19. CLOSTRIDIA

20. Clostridium tetani and C. perfringens

21. Enterococci spp
Indicators of faecal contamination by bacteria.

22. 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

23. Escherichia coli

24. 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

25. Legionella pneumophila
Infection by inhalation
Is considered highly
dangerous: In many
countries has its own rules
and regulations for control
and analysis

26. ILLNESS LEGIONELLOSIS
MICROORGANISM Legionella pneumophila
Range 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

27. 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
networks
Additional 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

28. PROTOZOA: GIARDIA LAMBLIA

29. WATER-RELATED PARASITES
GIARDIA 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 microvilli.
Its incubation period is from 1 to 3 weeks. Man is the only host.
Symptomatology: Lasts for 2 to 6 weeks. Diarrhoea, belly distension and
abdominal pain, anorexia.
To note: resists chlorination of water

30. OOCYSTS: CRYPTOSPORIDIUM

31. In water oocysts can be found, extremely
resistant thanks to their protecting
Pathogenicity: 2-14 days Incubation, with symptoms up to 2 weeks in healthy
persons
For immuno-depressed people can be deathly
Symptomatology:
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 PARASITES
CRYPTOSPORIDIUM PARVUM

32. Round worms: long, cylindrical and not-segmented body. Size from less than 1
mm to several cm
Can cause haemorrhages, anaemia, paleness, loss of weight, diarrhoea
syndrome, general feeling of discomfort, etc.
ÁSCARIS LUMBRICOIDES ANCYLOSTOMA DUODENALE TRICHURIS TRICHURA
WATER-RELATED PARASITES:
NEMATODES

33. 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 cat.
Symptomatology:
For healthy people the symptomatology is similar to the flue.
For the foetus the consequences are malformations; and heart, liver and brain
affectation.
In immuno-depressed individuals an 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 PARASITES
TOXOPLASMA GONDII

34. TOXOPLASMA GONDII

35. WORMS: NEMATODA

36. VIRUS

37. AIDS virusBacteriophage (model)
VIRUS

38. VIRAL FORMS

39. INFECTION: VIRUS “LYSIS CICLE”

40. • Fungi and yeasts
• Algae and its “by-
products”
OTHER MICROORGANISMS IN WATER