1) The study investigated the susceptibility of urinary tract infection-causing E. coli bacteria to green tea extract.
2) 80 E. coli isolates representing different antimicrobial resistance patterns were tested, along with 2 control strains.
3) The minimum inhibitory concentration of green tea extract was determined, with 99% of isolates being inhibited by 4.0 mg/ml or less of green tea extract.
1. Wanda Reygaert 1* and Ilir Jusufi2 1 Department of
Biomedical Sciences, Oakland University William
Beaumont School of Medicine,
Rochester, MI, USA 2 Biomedical Diagnostic and
Therapeutic Sciences Program, Oakland University
School of Health Sciences,
2. Urinary tract infections (UTIs) are the second most common
type of infection found in any organ system, and the most
common type of nosocomial infection
These UTIs are responsible for over eight million doctors
visits per year in the US and result in medical costs of over six
billion dollars worldwide per year
Most UTIs (80–90%) are the result of infections with
Escherichia coli
3. Non-pathogenic strains of E. coli are an important part of the
normal flora in the intestinal tract.
The strains of E. coli that infect the urinary tract are
categorized as uropathogenic E. coli
The UPEC are able to produce special surface proteins
(adhesins) that allow them to attach to and invade the
epithelial cells that line the urinary bladder
If the infection is not eradicated while it is in the bladder ,
some strains of UPEC may then travel up the ureter to the
kidneys and cause even more severe infections (complicated
UTIs), which can lead to renal damage and possibly renal
failure
4. There are 14 serogroups of UPEC that are most commonly
found in UTIs, and 75% of UTIs have been shown to be caused
by serogroups 04, 06, 014, 022, 075, and 083
The most common serogroups involved in causing UTIs
worldwide are 02, 04, 06, and 075
In the U.S., 49% of UTIs in women have been found to be
caused by serogroups 06, 04, and 075, in descending
frequency of occurrence
5. The antimicrobial agents that have traditionally been used to
treat UTIs (β-lactams, fluoroquinolones, trimethoprim–
sulfamethoxazole, nitrofurantoin, etc.) are becoming less
effective
In recent years, the number of antimicrobial resistant strains
of E. coli isolated from UTIs has been increasing, including
resistance to antimicrobial agents normally used to treat UTI.
6. A urinary tract infection (UTI) is an infection involving the
kidneys, ureters, bladder, or urethra. These are the structures
that urine passes through before being eliminated from the
body.
The upper urinary tract is composed of the kidneys and
ureters. Infection in the upper urinary tract generally affects
the kidneys (pyelonephritis), which can
cause fever, chills, nausea, vomiting, and other severe
symptoms.
7. The lower urinary tract consists of the bladder and the
urethra. Infection in the lower urinary tract can affect the
urethra (urethritis) or the bladder (cystitis).
Urinary tract infections are much more common in adults
than in children, but about 1%-2% of children do get urinary
tract infections.Urinary tract infections in children are more
likely to be serious than those in adults and should not be
ignored (especially in younger children).
8. These infections are much more common in girls and
women than in boys and men younger than 50 years of
age. The reason for this is not well understood, but
anatomic differences between the genders (a shorter
urethra in women) might be partially responsible.
About 40% of women and 12% of men have a urinary
tract infection at some time in their life.
9. Green tea is derived from non-fermented leaves of the
Camellia sinensis plant. Oolongand black tea are made from
fermented leave from the same plant. Green tea has been a
falvoured drink, traditionally, in Asian countries. Because of
studies that have shown the potential health benefits of green
tea, it is now gaining worldwide popularity as a drink that is
important in preventative medicine. Studies using green tea
have show init to have potential benefits, most notably in :
cardiovascular disease, cancer, diabetes ,obesity, oral health,
bone health ,and cognitive function.
10. Catechins
(Astringency component in tea)
Decreases blood cholesterol
Body fat reduction
Cancer prevention effect
Antioxidant
Tooth decay prevention, antibacterial effect
Anti-influenza effect
Inhibits high blood pressure
Anti-hyperglycemic effect
Bad breath
11. Vitamin E
Antioxidant
β-carotene
Maintenance of nightime vision
Fluorine
Prevention of tooth decay
(
13. Catechins
Catechins are a type of polyphenol and are the main astringency component
in green tea, long known as tannins. Catechin was first isolated from the
Indian plant extract catechu (from the plant acacia catechu, a tree of the
fabaceae family, acacia genus), from which it derives its name. Tea catechin
was first isolated by Dr. Michiyo Tsujimura in 1929 at RIKEN (The Institute of
Physical and Chemical Research) in Japan. There are four main types of
catechins found in tea leaves.
Epicatechin
Epigallocatechin
Epicatechin gallate
Epigallocatechin gallate
14. Three of these catechins, ECG, EGC, and EGCG have been show
to have antimicrobial effects against a wide variety of
microorganisms
The two found in the highest amounts in green tea are EGC and
EGCG. Both of these are excreted in bile, but EGC is also
excreted in the urine, suggesting the possibility for green tea
having antimicrobial activity in UTI
15. The aim of the current study was to investigate the
susceptibility of UPEC strains, representing a wide variety of
antimicrobial susceptibility patterns, to green tea.
16. 1: The bacterial strains used for this study were part of a
research collection of E.coli
Isolated from UTI cultures during the year 2007-2008.
2: 80 isolates were selected from this collection that
represented a wide spectrum of antimicrobial susceptibility
pattern.
3: two control strains that were susceptible to all the clinically
tested antimicrobials were selected.
17. 1: A standardized green tea (C.sinensis) extract (standardized to 7.0%
polyphenols) was obtained from Swanson Vitamins®.
2: HOW TO EXTRACT??
Strong infusions:
a) Green tea leaves are processed by soaking in the aqueous solution of
alcohol
b) Purified extracts: Further purification is done by chromatography or
solvent extraction
3: The plant extract was prepared in water.
SWANSON VITAMINS®:They produce health products.
18. 1: The media used in this experiment is LA
(Luria-Bertani)
2: Dehydrated Muller –Hinton agar (MH
media)
Muller- Hinton agar is used in Antimicrobial
susceptibility test.
19. E.coli strain O157:H7 can cause severe problems in
the intestine and urinary track
It produces a toxin that in the intestine and damages
the wall of the intestine.
TWO TYPES OF UTI’s.
1: Cystitis(infection of the bladder): by the E.coli
found in the gastrointestinal track.
2: Urethritis(infection of the urethra):when the
gastrointestinal E.coli spreads from anus to the
urethra.
CAUSES:
Sexual contact, contaminated water or food.
COMPLICATIONS: Permanent kidney damage.(chronic
kidney infection)
20. PROCEDURE:
1: The minimum inhibitory concentration of the green tea
extract was determined by agar dilution method.
2: The MHA plates contain various concentration of green
tea extract(0,2.5,3.0 and 4.0 mg/ml)
3: Suspensions of 0.5 McFarland standard dilutions were
prepared from bacterial culture grown overnight in LB
broth.
4: A 10-4 dilution of these suspensions was prepared
and 100µl of dilution of dilution per plate was inoculated
using spread plate technique.
21. 5: The plated concentration equals 1.5×10-
3.was incubated at 37˚C for 48hours , and
on the basis of colony counts, the MIC was
determined as the lowest concentration of
green tea extract to show an inhibitory effect
on growth of bacteria (no colonies
detected).Each strain was tested three times.
22. MIC DETERMINATION:
The MIC and susceptibility results were as follows:
1: 99% were susceptible to green tea extract at a concentration
of ≤4.0mg/ml.(one strain was not suscetible at even 4.0mg/ml)
2: 94% were susceptible at ≤3.5mg/ml.
3: 76% was susceptible at ≤3.0mg/ml.
4: 40% was susceptible at ≤2.5mg/ml
5: The control strain varied; one being susceptible at
≤2.5mg/ml and the other susceptible at ≤3.5mg/ml
23. COMPONENT Number of isolates tested
(% out of 79)
32(40%) 29(37%) 14(18%) 4(5%)
Total GTE (mg/ml) < 2.5 <3.0 <3.5 < 4.0
or or or or
= 2.5 =3.0 =3.5 =4.0
EGC (microgram/ml) < 450 <540 < 630 < 720
or or or or
= 450 = 540 = 630 = 720
24. 1: This study shows that green can have an
antimicrobial effect on E.coli bacteria that
causes UTI’s.
2: This research data also adds to the current
information on the potential health benefits of
green tea.
-traditionally used to control bleeding and heal
wounds, aid digestion , improve heart and
mental health in India and China.
