Survival of Selected Bacteria Causing Traveler’s Diarrhea in Common Water and Beverages
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Transcript of Survival of Selected Bacteria Causing Traveler’s Diarrhea in Common Water and Beverages
Survival of Selected Survival of Selected Bacteria Causing Traveler’s Bacteria Causing Traveler’s DiarrheaDiarrhea in Common Water Water
and Beverages and Beverages Presented By:
Majed Al-Mashjary Ammar Basabrain
Mohammad Raml Majed Al-Shaer
Supervised By: Dr. Abdulaziz Bamarouf
Outlines• Introduction about Traveler’s Diarrhea
• Aims of this Project
• Materials & Methods
• Results
• Discussion
• Conclusions
What is Traveler’s Diarrhea?
• Traveler’s diarrhea is a syndrome characterized by a two time or greater increase in the frequency of unformed bowel movements
• Commonly associated symptoms include abdominal cramps, nausea, urgency, fever, and malaise
• Cases of Traveler diarrhea usually begin by surprise (sudden onset ) and occur during travel or soon after returning home and are mainly self-limited condition
Traveler’s Diarrhea Can Cause More than a Stomachache!
Common Signs and Symptoms
Upset stomach
Vomiting
Diarrhea Fever
Dehydration
Don’t Count on these to Test for Food Safety!
Sight
Smell Taste
Who is at risk?
• Our immune system helps in fighting Infections.
• But the immune systems of very young children, pregnant women, the elderly, and chronically ill people are at greatest risk to develop diarrheal infections
Infants and young children, in particular, produce less acid in their stomachs, making it easier for them to get sick
For pregnant women, the fetus is at risk because it does not have a fully developed immune system
For elderly individuals, poor nutrition, lack of protein in the diet, and poor blood circulation may result in a weakened immune system
Those who are immunocompromised, such as diabetics, cancer patients, AIDS patients, and people on antibiotics are at greater risk
Etiological Agents of Traveler’s Diarrhea
• Bacterial causes
• Parasitic causes
• Viral causes
Bacterial Causes
• The majority of cases of traveler’s diarrhea are caused by enteric bacterial pathogens, which are most likely acquired by ingesting contaminated food or water
Salmonella• S. typhi which cause
Typhoid fever.
• Typhoid fever is an
important cause of
morbidity in many
regions of the world, with an estimated 12 to 33 million cases occurring yearly
Shigella• The etiological agent of Shigellosis is a
highly contagious and severe inflammatory diarrhea disease
• Sh. flexneri is the predominant species responsible for endemic disease
• Each year there are about 160 million cases of shigellosis resulting in more than one million deaths
Other Bacterial Etiological Agents
Pathogenic Escherichia coli
Campylobacter spp.
Vibrio spp.
Aeromonas spp
Bacterial Food Poisoning
• Bacterial food poisoning may in some circumstances be an important cause of diarrhea that typically occur in outbreaks
• Staphylococcus aureus
• Bacillus cereus
• Clostridium perfringens
Distribution of Traveler’s Diarrhea in the World
• In general, countries with higher standard of hygiene have lower risk for traveler’s diarrhea
WWW.CDC.GOV
Water and Beverages Precautions• Water• Many pathogens causing traveler’s diarrhea
have proved their ability to cause disease through tap water.
• Tap water in many developing countries is often hazardous, particularly in rural areas or after rainfall
• Ingestion of pathogens may occur by swallowing water while showering or by using tap water for brushing teeth
• Ice cubes is one way of ingestion of untreated tap water specially with a pathogen of a low infectious dose such as Shigella spp
• Finally, swimming in water that is contaminated by sewage should be avoided
• Non-carbonated bottled water • Although non-carbonated bottled water
is often used as an alternative, it is only as safe as the source from which it was taken
• The viability of pathogens can be maintained in non-carbonated bottled water; in some cases, this vehicle has been a contributor to epidemics of cholera and typhoid fever
• Tea and coffee
• Tea and coffee are safe if consumed hot, whereas ice tea or coffee is not safe except if prepared commercially and bottled
• Carbonated beverages • Carbonated beverages have the
advantage that they are bactericidal
• Carbonation result in an acid pH that will effectively kill bacteria over a period of time
• Commercially bottled carbonated beverages are highly recommended as a fluid source for travelers
• Unpasteurized milk
• Unpasteurized milk and milk products are to be avoided entirely, including ice cream and small quantities of milk in tea or coffee
• Finally , travelers have to be note that some beverage consumed in great quantity can contribute to diarrhea either through the action of caffeine or the effect of high sugar like fructose
• Diet drinks containing aspartame (artificial sugar) may also produce diarrhea
Aims of This Project
1) To determine the survival of common bacterial pathogens causing traveler’s diarrhea in:
Water Carbonated drinks Fruit-based carbonated drinks Energy drinks Fresh juices
2) To measure the pH of all water and beverages used in this study
Materials & Methods
• Bacterial Source: Salmonella typhi Shigella flexneri clinical isolates from culture collection of
microbiology laboratory in the Faculty of Medicine, King Abdulaziz University
• Agar Media Nutrient Agar (Oxoid, UK)
Drinks Ingredients
1) Carbonated Drinks: • Pepsi • Diet Pepsi
Ingredients: • Carbonated water • phosphoric acid • Sugar (aspartame in diet)• natural cola flavored • caffeine
2)Carbonated Flavored Drinks:• 7up • Diet 7up
Ingredient:• Carbonated water • citric acid • natural citrus flavored• Sugar (aspartame in diet)• Na citrate • Na benzoate
3) Energy Drinks:• Power horse • Diet Power horse • Bison • Red Bull
Ingredients:• Carbonated water • citric acid • Sugar (aspartame in diet)• caffeine • Na citrate • Vitamins
4) Water:• Tap water • Bottle water • Evian water • Volvic Flavored water
Ingredients: • Cations • Anions • * For volvic additional• Citric acid • Natural flavor
5) Fresh Juices: • Fresh lemon juice without sugar• Fresh lemon juice with sugar• Fresh orange juice without sugar • Fresh orange juice with sugar
• pH measurement:• pH of all water and beverages were
measured using standard pH meter
• Procedure Determination of the survival of
Salmonella and Shigella in different water and beverages drinks
1- For each bacterium, 14 separate sterile tubes were labeled with each water and beverages drinks
2- Five (5) ml of each water and beverages drinks were added to each tube
3- One McFarland standard of each
bacterial suspension was prepared using sterile physiological saline
4- Then 100 µl of bacterial suspensions were added to each of the labeled tubes containing water and beverages drinks
5- All bacterial/drink mixtures were mixed well and left to stand for 30 minutes at room temperature
6- Then fixed amount from each mixtures were cultured in separate Nutrient agar medium by streaking on agar plates to grade bacterial survival
7- Then all agar plates were incubated for 24 hours at 37° C aerobically
8- The remaining bacterial/drink mixture (from step 5) were re-incubated for further 24 hours and then cultured again
9- All plates were examined for bacterial survival by interpretation of the results using streaking in agar plate’s method as follow:
0 = no growth
+1= growth only in primary streak
+2 = growth in the first and second streak.
+3 = growth in the first, second and third
streak
+4 = growth in the first, second, third and fourth streak
Survival of S. typhi in Water & Beverages
0
1
2
3
4
Growth in 30 min
Growth in 24 hr.
Survival of Sh. flexneri in Water & Beverages
0
1
2
3
4
Growth in 30 min
Growth in 24 hr.
pH Measurement of Water & Beverages
00.5
11.5
22.5
33.5
44.5
55.5
66.5
77.5
88.5
9
pH
Discussion
•The main aims of this project were to determine the survival of S. typhi and Sh. flexneri in different water and beverages and to measure pH of all drinks
•As results indicate that some water and beverages were not bacteria friendly and bacteria die after either 30 min or 24 hours
The bad side of soft drinks
1 - The high sugar content and low dietary value which is propriety of junk drink
2- Their affect on dental erosion
3- Their caffeine content and aspartame
which affects the body
The antibacterial killing of lemon juice as a natural drink is better than consuming soft drinks which have bad effect
Conclusion
Extensive consumption of one or other of these drinks may prevent illness
Additional clinical and epidemiological studies are needed to further define the safety and suitability of drinks for consumption by foreign travelers.
Acknowledgement
• We thank allah for guiding us to the right path.
• We thank our supervisor for supporting us & being beside us till the very last minute.
Dr. Abdullaziz Bamarouf • Also we thank our family for their
patience & supporting us & for being there for us.