Sunday, December 2, 2007

Group Post: MMIC dPBL 1

List of possible organisms for each case
Diagnosis Possible bacteria species Morphology & Microscopy
Case 1 Urinary Tract Infection (UTI)
Staphylococcus aureus

Staphylococcus saprophyticus

Enterococcus faecalis

Gram Positive, Spherical-shaped, immobile and form grape-like clusters

Gram Positive, Cocci-shaped occur singly and in pairs, short chains, and grape-like clusters

Gram Positive, Cocci-shaped in pairs and chains
Case 2 Enterocolitis
Campylobacter jejuni

Shigella species

Salmonella species

Escherichia coli (entero-pathogenic; EPEC)

Clostridium perfringens

Clostridium difficile

Vibrio Cholerae

Vibro parahemolyticus

Bacillus cereus

Yersinia enterocolitica

Staphylococci aureus

Gram-negative rods

Gram-negative rods

Gram-negative rods

Gram-negative rods

Gram-positive rods

Gram-positive rods

Gram-negative rods

Gram-negative rods

Gram-positive rods

Gram-negative rods

Gram-positive cocci
Case 3 Urinary Tract Infection (UTI)
E. coli

Klebsiella sp (Klebsiella pneumuniae, Klebsiella oxytoca)

Enterobacter (Enterobacter aerogenes)


Proteus mirabilis

Morganella morganii

Pseudomona aeruginosa

Staphylococcus aureus

Staphylococcus saprophyticus

Enterococcus sp.

Gram negative bacilli

Gram negative bacilli

Gram negative bacilli

Gram negative bacilli

Gram negative bacilli

Gram negative bacilli

Gram negative bacilli

Gram positive cocci

Gram positive cocci

Gram positive cocci
Case 4 Bronchitis
Strep. Pneumoniae

Klebsiella-Enterobacter-Serratia (Klebsiella sp.)

Bordetella pertussis

Gram positive, diplococci, lancet-shaped

Gram negative rods

Gram negative, coccibacilli
Case 5 Wound Infection
Beta Haemolytic Streptococci (Streptococcus pyogenes)

Enterococci (Enterococcus faecalis)

Staphylococci (Staphylococcus aureus/MRSA)


Pseudomonas aeruginosa

Enterobacter species

Escherichia coli

Klebsiella species

Proteus species


Gram-positive facultative anaerobes cocci

Gram-positive facultative anaerobes cocci

Gram-positive facultative anaerobes cocci

Gram-positive anaerobe rod

Gram-negative aerobic rods

Gram-negative facultative rods

Gram-negative facultative rods

Gram-negative facultative rods

Gram-negative facultative rods

Gram negative Anaerobes rods
Case 6 Urinary Tract Infection (UTI)
Gardnerella vaginalis

Chlamydia trachomatis

Neisseria gonorrhoeae

Ureaplasma urealyticum

Staphylococcus saprophyticus

Enterobacteriaceae (E. coli, serratia, klebsiella, enterobacter, citrobacter)


Gram-negative rod with a gram-positive cell wall

Gram-negative bacteria, coccoid or rod-shaped

Gram negative cocci

Gram-negative bacteria

Gram positive, globular shaped, colonies resemble grape-like clusters

Gram-negative, rod-shaped

Gram-positive cocci which often occur in pairs (diplococci)
Authors: Lizzie, Kent & Ye Tun, Joan, Charmiane, Ai Tee and Adrian (according to case no.)

Brief description of diagnosis:

1. Urinary Tract Infection (UTI)

A urinary tract infection (UTI) is a bacterial infection that affects any part of the urinary tract. The urinary tract is made up of the kidneys, ureters, bladder, and urethra, and each plays a role in removing liquid waste from the body. Although urine contains a variety of fluids, salts, and waste products, it usually does not have bacteria in it. When bacteria get into the bladder or kidney and multiply in the urine, they cause a UTI.

Cystitis: bladder infection.

Pyelonephritis: kidney infection is much more serious.

Urethritis: urethra infection.

Each type of UTI may result in more specific signs and symptoms, depending on which part of your urinary tract is infected. The symptoms shown in acute pylonephritis are closest to what is given in the case study, whereby it is an infection of your kidneys may occur after spreading from an infection in your bladder. Kidney infection can cause upper back and flank pain, high fever, shaking chills, and nausea or vomiting.

Pyelonephritis is an inflammation of the kidney and upper urinary tract that usually results from noncontagious bacterial infection of the bladder (cystitis). In acute pylonephritis, bacteria begin colonising the tubules and connective tissue of the kidney itself. Small abscesses and streaks of pus begin to appear in the renal cortex and medulla respectively. Pyelonephritis most often occurs as a result of urinary tract infection, particularly in the presence of occasional or persistent backflow of urine from the bladder into the ureters or kidney pelvis (vesicoureteric reflux).

Urinary catheterization is the insertion of a catheter into a patient's bladder through the urethra, to drain urine from the bladder into an attached bag or container. Indwelling catheters should be restricted to patients whose incontinence is caused by urinary tract obstruction that can not be treated, and for which alternative therapy is not feasible. However, the catheter may introduce bacteria into the urethra and bladder, resulting in urinary tract
infection. The risk for developing a UTI increases when long-term catheterization is required.

Bacteria causing UTI may be isolated from the vaginal discharge. UTI can also result from sexual intercourse where bacteria from the vaginal area is transferred to the urethra and bladder.

Authors: Lizzie, Joan and Adrian

2. Enterocolitis

Enterocollitis is the inflammation of the small intestine and colon. Disease-causing bacteria usually invade the small intestines and colon and cause inflammation (blood or pus in the stool, fever) and abdominal pain and diarrhea. Campylobacter jejuni is the most common bacterium that causes acute enterocolitis in the U.S. Other bacteria that cause enterocolitis include Shigella, Salmonella and EPEC (E. Coli Enteropathogenic). These bacteria usually are acquired by drinking contaminated water or eating contaminated foods such as vegetables, poultry, and dairy products.

Enterocolitis caused by the bacterium Clostridium difficile is unusual because it often is caused by antibiotic treatment. It is also the most common nosocomial infection (infection acquired while in the hospital) to cause diarrhea.

E. coli O157:H7 produces a toxin that causes hemorrhagic enterocolitis (enterocolitis with bleeding). There was a famous outbreak of hemorrhagic enterocolitis in the U. S. traced to contaminated ground beef in hamburgers (hence it is also called hamburger colitis).

Bacterial overgrowth of the small intestine.

Because of small intestinal problems, normal colonic bacteria may spread from the colon and into the small intestine. When they do, they are in a position to digest food that the small intestine has not had time to digest and absorb. The mechanism that leads to the development of diarrhea in bacterial overgrowth is not known.

Authors: Kent and Ye Tun

3. Bronchitis

Bronchitis is an inflammation of the bronchi of the lungs. There are two main types of bronchitis: acute and chronic bronchitis.

Acute bronchitis can be caused by viruses such as influenza A and B, parainfluenza virus, respiratory syncytical virus, coronavirus, adenovirus, and rhinovirus. Bacterias are also able to cause acute bronchitis. Air pollutants such as cigarette smoke, dusts, or fumes of chemicals are also able to cause acute bronchitis.

The symptoms of acute bronchitis include:

* Sore throat

* Chest congestion

* Sinus fullness

* Breathlessness

* Wheezing

* Slight fever and chills

* Overall malaise

* Cough

Chronic bronchitis is where by the signs and symptoms become prolonged, and is defined clinically as a
persistent cough that produces sputum (phlegm) and mucus, for at least three months in two consecutive years. Chronic bronchitis is part of chronic obstructive pulmonary disease (COPD).

Author: Charmaine

4. Surgical Site Infection (SSI)

There are different levels of SSI:

• Superficial incisional, affecting the skin and subcutaneous tissue.

• Deep incisional, affecting the facial and muscle layers.

• Organ or space infection affecting any part of the anatomy opened or manipulated during the operation.

Symptoms: Pain, fever, inflammation, swelling and pus formation

Causes of infection:

-Microbes contamination (most commonly by S. aureus, S. pyogenes or P. aeruginosa

-Migration of patients’ own bacterial normal flora

-The materials or equipment used in the operational procedures (for e.g.: poor surgical techniques)

Author: Ai Tee

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