LAB 304
Final

Lecture \ 4
_

Blood culture
• Blood culture : is a microbiological culture of blood.
It is employed to detect infections that are spreading through the bloodstream (such as bacteremia or septicemia amongst others). This is possible because the bloodstream is usually a sterile environment.
• N.B : blood does not have a normal microbial flora .

Blood culture
• Whenever possible blood should be collected before antimicrobial treatment has started .
1- when the patient has recurring fever collect the blood as the temperature begins to rise .
2- for other patients collect the blood as soon as possible after receiving the request .
* To increase the chance of isolating a pathogen it is usually recommended that at least two specimens are collected at different times.

Urine collection
• Untimed urine sample (random) ( single sample )
• Timed urine sample ( 24 H sample )
• First Morning Specimen
• Midstream Clean Catch Specimen
• Catheter Collection Specimen
• Pediatric Specimen

Urine collection
1- Random Specimen
• This is the specimen most commonly sent to the laboratory for analysis, primarily because it is the easiest to obtain and is readily available.
• This specimen is usually submitted for urinalysis and microscopic analysis, although it is not the specimen of choice for either of these tests.
• Random specimens can sometimes give an inaccurate view of a patient's health if the specimen is too diluted and analytic values are artificially lowered.

Urine collection
1- Random Specimen
• As the name implies, the random specimen can be collected at any time. Although there are no specific guidelines for how the collection should be conducted, avoiding the introduction of contaminants into the specimen is recommended. This requires explicit instructions to patients so that they do not touch the inside of the cup or cup lid.

Urine collection
2- Timed Collection Specimen
• Among the most commonly performed tests requiring timed specimens are those measuring creatinine, urine urea nitrogen, glucose, sodium, potassium and other analytes that are affected by diurnal variations.
• A timed specimen is collected to measure the concentration of these substances in urine over a specified length of time.

Urine collection
2- Timed Collection Specimen
•
You should collect every drop of urine during each
24-hour period. It does not matter how much or little urine is passed each time, as long as every drop is collected.
•
Begin the urine collection in the morning after you wake up, after you have emptied your bladder for the first time.
•
Urinate (empty the bladder) for the first time and flush it down the toilet. Note the exact time (e.g,
5:00 AM). You will begin the urine collection at this time.

Urine collection
2- Timed Collection Specimen
•
Collect every drop of urine during the day and night in an empty collection bottle. Store the bottle at room temperature or in the refrigerator.
•
If you need to have a bowel movement, any urine passed with the bowel movement should be collected.
•
Finish by collecting the first urine passed the next morning, adding it to the collection bottle. This should be within ten minutes before or after the time of the first morning void on the first day (which was flushed).
In this example, you would try to void between 4:50 and 5:10 on the second day.

Urine collection
2- Timed Collection Specimen
• It is not recommended that the patient void directly into the 24 hour collection container due to the preservative acid content inside the container.
• The patient is encouraged to void into a separate (beaker style collection with pour spout ) cup and pour the contents into the 24 hour collection container during the collection process.

Urine collection
3- First Morning Specimen
• This is the specimen of choice for urinalysis and microscopic analysis, since the urine is generally more concentrated (due to the length of time the urine is allowed to remain in the bladder) .
• Also called an 8-hour specimen, the first morning specimen is collected when the patient first wakes up in the morning, having emptied the bladder before going to sleep.

Urine collection
• This is the preferred type of specimen for culture and sensitivity testing because of the reduced incidence of cellular and microbial contamination.
• Patients are required to first cleanse the urethral area with soap . The patient should then void the first portion of the urine stream into the toilet.
These first steps significantly reduce the opportunities for contaminants to enter into the urine stream. The urine midstream is then collected into a clean container . This method of collection can be conducted at any time of day or night.

Urine collection
• This assisted procedure is conducted when a patient is bedridden or cannot urinate independently. The healthcare provider inserts a Foley’s catheter into the bladder through the urethra to collect the urine specimen.

Urine collection
6- Pediatric Specimen
• For infants and small children, a special urine collection bag is adhered to the skin surrounding the urethral area. Once the collection is completed, the urine is poured into a collection cup or transferred directly into an evacuated tube with a transfer straw.

Sputum collection
• Specimen required is From the lower respiratory tract expectorated by deep coughing .
• Sputum specimen collection can be either selfexpectorated or mechanically obtained.
• Sputum samples should be collected in the morning before breakfast if possible , because sputum collects during the night.

Sputum collection
PROCEDURE
1- Wash hands thoroughly
2- Assemble necessary equipment.
3- Confirm the patient’s identity using two patient identifiers.
4- Tell the patient that :
* you will collect a specimen of sputum (not saliva) and explain the procedure.
* The cup is very clean. So Don’t open it until you are ready to use it.

Sputum collection
PROCEDURE
5- Instruct the patient to sit in a chair or at the edge of the bed. If the patient cannot sit up place him in high
Fowler’s position.
* Place the head of the bed at 30° for semi-Fowler's, 45° to 60° for Fowler's, and 90° for high Fowler's

Sputum collection
PROCEDURE
6- Ask the patient to rinse his/ her mouth with water
(avoid mouthwash solution or toothpaste).
7- Tell patient to cough deeply and expectorate directly into the specimen container. At least 15 ml is needed to identify the causative organism.
8- Cap the container and if necessary, clean its exterior.

Sputum collection
• Purpose :
For the detection of the causative agent of pneumonia, bronchitis, lung abscess or tuberculosis .
Examples of common causative agents of bacterial pneumonia:
• Streptococcus pneumoniae,
• Haemophilus influenzae,
• Staphylococcus aureus,
• Klebsiella pneumoniae,
• Escherichia coli, and
• Pseudomonas aeruginosa.

Fecal sample
• Collect the stool in a dry, clean, leak-proof container.
• Make sure no urine, water, soil or other material gets in the container.
• Insure that the specimen containers are sealed well. Reinforce with parafilm or other suitable material.
• Insert the container in a plastic bag.
• Certain drugs and compounds will render the stool specimens unsatisfactory for examination. The specimens should be collected before these substances are administered, or collection must be delayed until after the effects have passed.

Lecture \ 5
_

Throat swab
Procedure
1- With the patient’s head tilted back and the throat well illuminated, depress the tongue so that the back of the throat can be seen.

Throat swab
Procedure
2- Rub the swab up and down the back of the throat and against any white patches in the tonsillar area.
Avoid the tongue and the cheeks.

Throat swab
Procedure
3- Replace the swab in the transport tube .
4- Seal tube tightly and label with patient’s information, and date .
5- Send the specimen to the laboratory .

• Gargling to clear the throat or treatment with antibiotics will affect culture results and may make identification of the bacteria impossible. The patient should not gargle immediately before the swab.

• Definition :
A throat culture is a microbiological procedure for identifying disease-causing bacterial organisms in material taken from the throat. A throat swab will capture the causative organism in most cases and the culture will allow the specific organism to be grown in the microbiology laboratory under certain conditions. The bacteria can then be identified .

• Purpose :
1- identify the specific bacterial organisms that are causing a sore throat or throat infection
2- a correct diagnosis is important to prevent unnecessary use of antibiotics for viruses that do not respond to them.
3- the bacteria identified are used to determine antibiotic sensitivity, allowing physicians to select the most appropriate and effective antibiotic to treat a specific infection.
• It is common for physicians to order culture and sensitivity tests at the same time. ( c/s test )

Vaginal swab
• Vaginal swabs are the specimens of choice when screening for :
1- Trichomonas vaginalis

Vaginal swab
2- candida species
Candida albicans

Vaginal swab
3- Gardnerella vaginalis with anaerobes .

Vaginal swab
Procedure
1- Place the patient in dorsal position, supported by a pillow
2- ask her to bring her heels together,
3- bend her legs and then draw her heels towards her bottom.
4- Open the swab package

Vaginal swab
Procedure
5- Remove the swab; do not touch the soft tip or lay the swab down.
6- Hold the swab as shown

Vaginal swab
Procedure
7- Insert the swab into the lower part of the vagina
(about two inches ).
8- Gently but firmly rotate the swab for 10 to 30 seconds in the vagina.
vagina

Vaginal swab
Procedure
9- Withdraw the swab without touching the skin.
10- Place the swab into the test tube so that the tip of the swab is visible below the tube label .
11- Ensure that the swab is labeled accurately and place, with the completed request form
12- transport bag to the Department of Medical
Microbiology.

Cervical swab
• Also it is called : Papanicolaou test ,Pap smear, Pap
test, cervical smear, or smear test .
• A sample of cells from the patient's cervix is collected and spread (smeared) on a microscope slide. The cells are examined under a microscope in order to look for pre-malignant (before-cancer) or malignant (cancer) changes.
• Changes can be treated, thus preventing cervical cancer, and cancer can be detected early.

Cervical swab
• The best time for screening is between 10 and 20 days after the first day of menstrual period .
• For about two days before testing, the patient should avoid douching or using spermicidal foams, creams, or jellies or vaginal medicines (except as directed by a physician). These agents may wash away or hide any abnormal cervical cells.

Cervical swab
Procedure
1- Place the patient in dorsal position, supported by a pillow
2- ask her to bring her heels together,
3- bend her legs and then draw her heels towards her bottom.

Cervical swab
Procedure
4- Moisten the speculum with warm water and insert into the vagina to separate the vaginal walls. Wipe away any excess cervical mucus with a tissue. Using a blue top Trans tube swab sample as high as possible into the vault.
5- Gently but firmly rotate the swab (a cervical brush)

Cervical swab
Procedure
6- Withdraw the swab without touching the skin.
7- Remove speculum and wipe vaginal / vulvar area with a tissue .
8- Place the swab into the test tube so that the tip of the swab is visible below the tube label .
9- Ensure that the swab is labeled accurately and place, with the completed request form
10- transport bag to the Department of Medical
Microbiology.

Lecture \ 6
) ةبولطملا حئارشلا ( يلاتلاك 6 ةرضاحملا _
4 · causes of sample rejection
بوطشم ريغلا · 10
12 /
بوطشم ريغلا
29
11
22 /
بوطشم ريغلا
33
32 /
21
·
31
·
/
/
·
20
30
5
·
·
·

• Reference values should be mentioned in the result report .
• Reference range : it is the interval between and including two reference limits ( upper & lower ) for the specific test .
• The test should be repeated if the results are out of range

• Causes of sample rejection?
1. Q.N.S sample. (Quantity of specimen not sufficient)
2. Clotted sample.
3. Hemolysed sample.
4. Sample collected in wrong tube.
5. Test N/A ( not available )
6. Specimen not labeled.
7. Incomplete request's information.

Normal ranges
Analyte Conventional Unit
WBC
HGB MALE
4500-11000/ µL
13.5-16.5 g/dl
HGB FEMALE
PLT
12.0-15.0 g/dl
150-350 x10³/ µL
HGB: Hemoglobin
PLT: platelets

Result interpretation
Type of Cell
RBC
WBC
NEU
EOS
BAS
LYMPH
MONO
PLT
Increased polycythemia leukocytosis neutrophilia eosinophilia basophilia lymphocytosis monocytosis thrombocytosis
INTERPRET
Primary & secondary polycythemia bacterial infection & acute inflammation
Allergic disorders & Parasitic infections myeloproliferative disorders & Allergic disorders acute viral infections , chronic intracellular bacterial infections (TB) & some protozoal infections (TOXO) chronic inflammation.
Inflammation , Surgery , Anemia or hemorrhage

Type of Cell
RBC
WBC
NEU
EOS
BAS
LYMPH
MONO
PLT
ALL CELL decreased erythroblastopenia leukopenia neutropenia
INTERPRET
Decreased production in the bone marrow ,
Increased destruction & Medications eosinopenia basopenia lymphocytopenia monocytopenia thrombocytopenia pancytopenia
Leukocytosis with eosinopenia can be a predictor of bacterial infection
Urticaria a recent infection e.g. common cold glucocorticoids
Vitamin B
12 or folic acid deficiency, Decreased production of thrombopoietin in liver failure & thrombocytopenic purpura
Aplastic anemia , Leukemia , SLE ,
Severe Folate or vitamin B12 deficiency , HIV ,
Pernicious anemia & Medications

Result interpretation
Conventional Unit Interpret Analyte
GLU
GLU: Glucose
Analyte
NA
K
Analyte
70-110 mg/dl
Conventional Unit
136-142 mEq/l
8-23 mg/dl
Conventional Unit
Increased in diabetes and severe illness; decreased in insulin overdose or hypoglycemia
Interpret
Increased in dehydration and diabetes insipidus; decreased in overload of IV fluids, burns,diarrhea, or vomiting
Increased in renal failure, extensive cell damage, and acidosis; decreased in vomiting, diarrhea, and excess administration of diuretics or IV fluids
Interpret
Ca 8.2-10.2 mg/dl Increased in excess parathyroid hormone production and in cancer; decreased in alkalosis, elevated phosphate in renal failure, and excess IV fluids

Critical values
• PROCEDURE :
1- A critical value result should be confirmed by repeating the test for a second time.
2- If the result is similar to the previous one, the comment code or footnote: CPR (Consistent with the Previous Result) is written by the lab technician.
3- If the result is critical and no history of pervious critical value for this test, the result is confirmed, and the doctor is called.

Analyte
Glucose
NA
K
Analyte
Ca
Analyte
WBC
HCT-hematocrit-
PLT
HGB
Some Critical values
Conventional Unit
Low
<40 or 45mg/dL
<120 mEq/L
<2.5 mEq/L
Conventional Unit
Low
<7.0 mg/dL
Low
≤ 2.0 x 109/L
Conventional Unit
< 20%
< 20 x 10-9/L
≤ 80 g/L
High
>500 mg/dL
>160 mEq/L
>6.0 mEq/L
High
>13.0 mg/dL
High
≥ 30 x 109/L
> 60%
> 1,000 x 10-9/L
> 200 g/L

Some of Critical values
• Positive blood culture
• Positive CSF (gram stain, culture)
• Positive AFB smear (new patient)
• Positive smear for P. Falciparum
• Positive Meningococcus (smear or culture)
• Positive new MRSA
• Positive salmonella or shigella and campylobacter
• Positive Clostredium perfringens
• Positive HIV, HEP B , HEP C , CMV
• Positive Respiratory Virus (RSV, Adeno, Inf…)

1
2
3

1- Physical examination
• Color
• Appearance
• Volume
• Specific gravity (SG)

NORMAL COLOR
• Including color and clarity
• Normal urine color ranges from pale yellow to deep amber

ABNORMAL COLOR
Abnormal color : some drugs and urinary tract infection cause color changes
1. reddish urine : hematuria, hemoglobinuria
2.
yellow brown or green brown urine: bilirubin cause : obstructive jaundice
3- greenish urine : infection
• Other abnormal colors : blue , orange , purple

Appearance
• Clarity: normally, clear
Abnormal appearance:
APPEARANCE
CLOUDY
RED & CLOUDY
YELLOW-BROWN OR
GREEN-BROWN
YELLOW-ORANGE
DUE TO RBC
DUE TO BILIRUBIN
DUE TO UROBILIN
POSSIBLE CAUSE
BACTERIAL URINARY INFECTION
1- URINARY SCHISTOSOMIASIS
2- BACTERIAL INFECTION
1- ACUTE VIRAL HEPATITIS
2- OBSTRUCTIVE JAUNDICE
1- HAEMOLYSIS
2- HEPATOCELLULAR JAUNDICE

Urine volume
• The average adult : 1000ml to 2000ml/24h
• Increased
POLYURIA---more than 2500ml of urine in 24 hours
1. physiological states: water intake, some drugs ( diuretics ), intravenous solutions
2. pathologic states: diabetes mellitus, diabetes insipidus

Urine volume
• Decreased
OLIGURIA : less than 400ml of urine in 24 hours
ANURIA : less than 100ml of urine in 24 hours
1. pre-renal: hemorrhage, dehydration, congestive heart failure
2. post-renal: obstruction of the urinary tract
(may be stones, carcinoma)

Specific gravity (SG)
• Reflect the density of the urine
• Range of 1.001 to 1.040
• Increased: Dehydration , Fever , Vomiting , Diarrhea ,
Diabetes Mellitus
(urine volume↓ and SG↑)
• Decreased: diabetes insipidus
(urine volume↑ and SG ↓)

2-Chemical examination
• Urine PH
• Protein
• Glucose
• Ketones
• Occult blood
• Bilirubin
• Urobilinogen
• Nitrites

Urine PH
• Normal PH
The average is about 6
Range from 5~7 (depends on diet)
• Higher PH---alkaline urine ( 7.8 – 8 .0 )
1.drugs: sodium bicarbonate
2.vegetarian
3.alkalosis (metabolic or respiratory)
4. urinary tract infection
• Lower PH---acid urine ( 4.5 – 5.5 )
1. drugs: ammonium chloride
2. diabetes
3. acidosis (metabolic or respiratory)

Protein in urine
• Reference value
Qualitative method: negative
Quantitative method: ＜ 150mg of protein in 24 hours
• Urine proteins come from plasma proteins e.g. albumin and Tamm-Horsfall (T-H) glycoprotein

Protein in urine
• The two most common risk factors for proteinuria are:
1. Diabetes
2. hypertension
• Proteinuria---＞ 150 mg /24 hours or qualitative test is positive
• Proteinuria quantification (amount of protein ) heavy proteinuria---＞ 4 g/24 hours moderate proteinuria----1 - 4 g/24 hours minimal proteinuria---＜ 1 g/24 hours

Protein in urine
Classification of Proteinuria
TYPE
Glomerular
Tubular
Overflow
PATHOPHYSIOLOGIC FEATURES glomerular capillary permeability to protein tubular reabsorption of proteins in glomerular filtrate production of low-molecular-weight proteins
CAUSE
Primary or secondary glomerulopathy e.g. IgA nephropathy, lupus nephritis
Tubular or interstitial disease due to:
Uric acid nephropathy
Heavy metals, NSAIDs
Monoclonal gammopathy, leukemia

Glucose in urine
• Reference value
Qualitative method: negative
• Glycosuria--- qualitative test is positive
1. with hyperglycemia ( most common ): diabetes mellitus, Cushing’s syndrome
2. without hyperglycemia (Renal glycosuria ): renal tubular dysfunction, such as pyelonephritis

Ketones in urine
• Including three ketone bodies:
1. acetone 2%
2. acetoacetic acid 20%
3. β-hydroxybutyric acid 78%
• The products of fat catabolism ( breakdown )
• Reference value: qualitative method: negative
• Ketonuria--- qualitative test is positive

Ketones in urine
• Ketonuria
1. diabetic ketonuria :
I.
Poorly controlled diabetes
II.
Diabetic ketoacidosis (DKA)
2. nondiabetic ketonuria:
I.
Acute or severe illness
II.
Burns
III.
Fever
IV.
Hyperthyroidism
V.
Pregnancy & lactation
VI.
Abnormal food or nutrition intake due to:
Anorexia, fasting, high protein or low carbohydrate diets, starvation, vomiting over a long period of time

Microscopic examination
• Examination
A- Cells
B- Bacteria
C- Crystals
D- Casts

Microscopic examination
A- Cells :
1- White Blood Cells (pus cell)
Normal <2/ HPF in men and <5/ HPF in women
• Few : up to 10/ HPF
• Moderate : 11-40 / HPF
• Many : > 40 / HPF
• HPF = high power field

Microscopic examination
2- Red Blood Cells : smaller and more refractile than white cells
Normal <3/ HPF
• Dysmorphic RBCs suggest glomerular disease

Microscopic examination
3- Epithelial cells : 3 types
1. Transitional epithelial cells are normally present

Microscopic examination
2. Squamous epithelial cells suggest contamination

Microscopic examination
3. Renal tubule epithelial cells suggest renal disease

Microscopic examination
B- Bacteria : Diagnostic for Urinary Tract Infection
• Men: Any bacteria
• Women: 5 or more bacteria per HPF

Microscopic examination
C- Crystals
1- Calcium oxalate crystals (square envelope shape)

Microscopic examination
2- Triple phosphate crystals (coffin lid shape)
• Associated with increased Urine pH (alkaline)
• Associated with Proteus Urinary Tract Infection

Microscopic examination
3- Uric Acid crystals (diamond shape)

Microscopic examination
D- Casts
1- Epithelial cell casts of renal tubule

Microscopic examination
2- Red Blood Cell casts

Microscopic examination
3- White Blood Cell casts

Microscopic examination
4- Hyaline or mucoprotein casts

Microscopic examination
5- Granular casts

Microscopic examination
6- Waxy casts

Microscopic examination
7- Fatty casts
Oval fat bodies ( OFB )

N
لماكلاب ناتيقابلا ناتارضاحملا _

n
Nosocomial infections ( hospital –acquired infection ):
An infection acquired in [a] hospital by a patient who was admitted for a reason other than that infection.
OR:
An infection occurring in a patient in a hospital or other health care facility in whom the infection was not present or incubating at the time of admission.

N
As a general timeline, infections occurring more than 48
hours after admission are usually considered nosocomial.
Frequency of infection:
Nosocomial infection occurs worldwide and affects both developed and poor countries.
According to studies conducted by WHO, 8.7% of hospitalized patients had nosocomial infection.

Factors influencing the development of nosocomial infection:
1-The microbial agents and antibiotic-resistance ability:
-Patients are exposed to a variety of microorganisms during a hospital stay:
A- Endogenous microbes: Part of a patient’s own flora.
B- Exogenous microbes:
Patients, and Visitors.
-Medical staff (doctor, nurse, physiotherapist, technician).
-Instruments (Endoscopy, catheter, surgical instruments)
-Fluids, blood, or food.
-Dust, and Insect bite.

N
Staphylococcus aureus (MRSA), coagulase-negative
Staphylococci, Enterococci (VRE), and Enterobacteriaceae species.
Viruses:
Hepatitis B and C, Rotaviruses, and Enteroviruses.
Fungi:
Candida albicans.

N
Hospital-dwelling bacteria could develop antibiotics resistance ability due to conjugation process.
Conjugation: Transfer of bacterial plasmid from one bacterium to another by sex pili.
Plasmid: Extracircular supercoiled DNA that carry some important gene such as the reporter genes (CAT gene).

N
2. Patient susceptibility:
Important patient factors influencing acquisition of infection are:
1-Age : infancy and old age.
2-Immune status : chronic diseases like malignant tumor, diabetes, renal failure immunosuppressive therapy and AIDS.
3-Underlying disease : injuries to skin (burn, wound), ischemia.
4-Malnutrition .
5-Diagnostic and therapeutic interventions : biopsies, catheterization, I.V. cannulation, endoscopic examination, incubation/ventilation.

n
3. Environmental Factors:
-Different factors play a role in establishment of
Nosocomial infections:
1-Crowded conditions .
2-Frequent transfer of patients from one unit to another.
3-Concentration of susceptible patients:
(newborn infants, burn patient, intensive care).
4-Microbial flora may contaminate objects, devices that may come in susceptible site of the patient.

Nimer
CONTAMINATED HOSPITAL ENVIRONMENT
Instruments, Fluids, Food,
Air, Medications
Patient Normal flora
Cutaneous, GIT,
Genitourinary,
Respiratory
Plasmid transfer
Invasive medical devices :
Iatrogenic
Urinary Catheter,
Intravenous catheter,
Endotracheal tubes,
Endoscopes
Medical Personnel: Colonized,
Infected, Transient, Carriers.

1. Urinary tract infections (UTI):
This is the most common nosocomial infection it account for
40 % of hospital acquired infections ; 80% of infections are associated with the use of an indwelling catheter .
Organisms :
E.coli, multi-resistant Klebsiella, Pseudomonas aeruginosa,
Enterobacter and Candida albicans.
Source:
Endogenous flora or exogenous from other patients, health care provider, instrument, etc.

N
Diagnosis: positive urine culture (1 or 2 species) with at least 10 5 bacteria/ ml , with or without clinical symptoms.
Prevention:
1-Remove the indwelling urinary catheter as soon as possible.
2-Use aseptic technique for inserting or manipulating the catheter.
3-Maintain an unobstructed urinary flow.
4-Ensure that the patient is taking sufficient amount of fluids per day (3-4 L).
5-Give proper antibiotic therapy for proper course.

N
2.Nosocomial Pneumonia:
Nosocomial pneumonia is the second most common nosocomial infection accounting for 15 % of all nosocomial infections.
It is associated with mortality rates that range from
20-50 % .
It occurs in several patient groups, the most important are patients on ventilator in intensive care units ( ICU ), where the Incidence rate of pneumonia is 3% per day .

N
Organisms:
Staph aureus, Pseudomonas , Enterobacter, Klebsiella pneumoniae, Candida albicans and Haemophilus
influenzae.
Source: endogenous from upper air way, and exogenous from contaminated respiratory equipment, patients, visitors, etc.
Diagnosis: isolation of microbe from clinical specimens, and presence of signs and symptoms of infect.

n
Prevention:
1-Wear gloves; for contact with respiratory secretions.
2-Wash hands after contact with respiratory secretions, even if gloves have been worn.
3-Maintain open airway.
4-Isolate patient with potentially transferred respiratory infections.

N
1-Surgical site infections: Staphylococcus aureus,
Staphylococcus epidermidis (Intravenous catheter).
2-Nosocomial Bacteremia.
3-Skin and soft tissue infections:
Open sores (ulcers, burns and bedsores).
4-Gastroenteritis :
The most common nosocomial infection in the children, where rotavirus is a chief pathogen.

N
5-Nosocomial Bloodborne diseases:
A-Hepatitis B virus:
-Transmission rate was 25%, reduced due to application of vaccination, the practice of not recapping needle , and Hepatitis B surface antigen screening test.
B-Hepatitis C: Rate is 3%.
Anti-viral drugs at first 8 hrs reduce the infection by
60%.
C-HIV: Rate is 0.3%

-Biological safety precautions.
-Hand hygiene.
-Clean & contaminated area.
-Management of blood & body fluid spillage.
-Immunization of health care workers.
-Post exposure management for health care workers.

Biological safety precautions:
1-All clinical specimens should be considered as potentially hazardous.
2-Wear Lab coat, gloves, shoes (Protective purpose).
3- Remove gloves when using the telephone or photocopier.
4- Skin cuts on the hands, must be covered with a waterproof dressing prior to start working.

n
5-Never perform any action which may bring your hands into contact with your face, eyes or mouth, such as eating, smoking or adjusting contact lenses.
6-Remove laboratory coat and gloves and wash hands before leaving your working area.

When Do We Need to Wash Our Hands?
-Before eating
-Before starting work
-Before and after any patient contact
-After contact with potentially contaminated materials like blood, urine, CSF.
-Before wearing gloves.
-After removing gloves.
-Before and after performing any medical procedure
-Before leaving work.

Types of Hand Hygiene (Decontamination):
1-Routine care (minimal):
-Hand washing with non antiseptic soap.
-Or quick hygienic hand disinfection by rubbing with alcoholic solution.
2-Antiseptic hand cleaning (moderate) – aseptic care of infected patients:
-Hygienic hand washing with antiseptic soap.
-Quick hand disinfection by rubbing with alcoholic solution.
3-Surgical scrub (surgical care):
Surgical hand and forearm washing with antiseptic soap and sufficient time and duration of contact (3 – 5 minutes).

Clean & contaminated area:
Control of spreading of infection could be achieved by classifying hospital environment into one of four zones:
Zone A: no patient contact. Normal cleaning .
(e.g. administration, library).
Zone B: Care of patients, who are not infected and not highly susceptible. Wet disinfection with detergent.
Zone C: infected patients (isolation wards).
Clean with a detergent/disinfectant solution, with separate cleaning equipment for each room.

N
Zone D: High–susceptible patient (protective isolation) or protected areas such as:
Operating room, delivery rooms, intensive care units, premature baby units, and haemodialysis unit.
-Clean using a detergent/disinfectant solution and separate cleaning equipment.

PURPOSE: To protect healthcare workers, patients and visitors from unnecessary exposures to bloodborne pathogens and other potentially infectious body fluids.
1-Low grade disinfection:
Quaternary ammonium : Bactericidal effect.
used for low amount- blood spillage.

N
2-Intermediate grade disinfection:
Phenol and 70-90% alcohol ;Bactericidal and
Virucidal effect.
Used for low amount -blood spillage (less than 50ml).
3-High grade disinfection:
Formaldehyde , Glutaraldehyde , Sodium hydrochlorite
, and hydrogen peroxide .
: Sporicidal ,Mycobactericidal, Fungicidal, and bactericidal effect.
Used for: high blood spillage (more than 50ml), and fungal decontamination.

NOSOCOMIAL INFECTION SURVEILLANCE:
The development of a surveillance is an essential first step to identify local problems , and evaluate the effectiveness of the infection control activity .
Objectives:
The purpose of surveillance program is to detect, record, and report hospital acquired infection aiming to reduce them and their costs.

N
2. Strategy of Surveillance:
A surveillance system must meet the following criteria:
Simplicity : to minimize costs and work load, and promote unit participation by feedback .
Flexibility : to allow changes when appropriate .
Acceptability : Evaluated by ICC according to data analysis .
Consistency : use standardized definitions and methodology
Sensitivity .
Specificity .

Infection Control Committee:
1-Management
2-Epidemiologist 3-Physicians
4-Other health care workers(Laboratory, or Nurse).
5-Clinical microbiologist 6-Pharmacy
7-Central supply 8-Maintenance
Tasks (most important) of the committee
-To review and approve a yearly program of activity for surveillance and prevention.
-To review epidemiological surveillance data and identify areas for intervention.

1-Direct patient care using practices which minimize infection.
2-Appropriate practice of hygiene:
(hand washing, and isolation).
3-Supporting the infection control team.
4-Protecting their own patients from other infected patients and from hospital staff who may be infected.
5-Obtaining appropriate microbiological specimens when an infection is present or suspected.

_ لماكلاب ناتيقابلا ناتارضاحملا

Stool analysis is a series of tests done on stool (feces) samples for differential diagnosis of certain diseases of digestive system.
• Diagnosis of digestive system infections: Bacteria, parasites, virus, and fungi.
• Diagnosis of pancreas disorders (inflammation); malabsorption of nutrients (fat).
• Primary screening test for some types of digestive system malignancy such as: colon cancer (occult blood).
• Primary screening for peptic ulcer disease, and some types of anemia (occult blood).

•
•
•
Patients with diarrhea.
Patients with abdominal pain.
Patients with anemia.
 Patients who is too thin or do not grow well.
 Patient with stool color that is changed to abnormal color.

•
• Color
• Consistency
•
• PH
• Sugar content.
• Fat content.
• Occult blood.
•

Color:
Normal feces is dark brown color (bilirubin in the presence of bacteria is oxidized to urobilinogen which is reduced to stercobilin which gives the stool its color).
Abnormal Color:
• Black color: blood of upper GIT origin.
• Red color: blood of lower GIT origin. yeast fermentation (Candida).
biliary obstruction or barium (swallow or enema).

N
Consistency:
• Normal feces is solid to semi-solid depending on the type of diet.
• Liquid stool indicates diarrhea (gastroenteritis).
• A ribbon like fecal specimen could indicate irritable bowl syndrome or GIT obstruction.
• Fatty stool indicates mal-digestion; Vitamins deficiency (A,D,E,K).

 The pH : The pH of the stool is 7.0-7.5 (low PH indicate carbohydrate malabsorption).
 Sugar contents:
The stool contains less than 0.25 grams per deciliter (g/dL) or less than 13.9 millimoles per liter (mmol/L) of sugars.
Elevated sugar indicates (more than 0.5g/dl): Lactose intolerance.

The stool contains 2-7 grams of fat /24h.
High levels of fat in the stool may be caused by diseases such as pancreatitis, cystic fibrosis, or celiac disease
(autoimmune allergy to gluten protein in wheat).
Test: add 95% ethanolic-Sudan black-II stain or acetic acid to the specimen: 60 red droplets of neutral fats on HPF is considered fat malabsorption ( steatorrhea).

N
Occult blood:
Stool guaiac test :
• Stool applied to a paper surface with phenolic compound alphaguaiaconic acid .
• Hydrogen peroxide is then added
• H2O2 oxidizes guaiaconic acid to dark-blue color within two seconds .
• Heme is a catalyst of this reaction.

N
Patients should be instructed to avoid eating red meat, horseradish, aspirin, or vitamin C as they interfere with the test by their catalases and peroxidases .
Clinical significance of the test:
- Diagnosis of colorectal cancer.
- Diagnosis of ulcerative hemorrhoids.
- Invasive gastroenteritis.

• Fecal leukocytes , especially neutrophils are associated with dysentery . They can be detected by stool smears stained with gram stain.
• Parasites: o Wet-mount smear (0.9% saline) or Iodine stained .
Protozoa.

• Entamoeba histolytica.
• Giardia lamblia.
• Balantidium coli.
• Ova ‘egg’:
• Schistosoma mansoni.
• Taenia worms
• Ascaris lumbricoides.
• Hook worms.
• Trichuris trichiura.
• Enterobius vermicularis.
• Larva: Strongyloides stercoralis.

- Offensive stool.
Macroscopic: Feces mixed with blood and mucus.
Microscopic: RBCs, pus, mucus, and Entamoeba histolytica cyst or/and trophozoite (central karyosome).
- Trophozoite show motility in one direction.

Entamoeba cyst (infective and diagnostic stage)
Entamoeba trophozoite (diagnostic stage)

N

 Gastrointestinal Mastigophora .
 Habitat: Small intestine especially in duodenum.
 Disease: Fatty diarrhea especially in children.
 Morphology:
•
•

Giardia cyst (infective and diagnostic)
Giardia trophozoite (diagnostic stage).

-

Schistosoma mansoni:
Trematoda.
Intestinal bilharziasis.
Diagnosis: finding of ova with lateral spine in the stool.

• Taenia saginata (beef tapeworm).
• Taenia solium (pork tapeworm).
Diagnostic stages: o Gravid segments. o Hexacantho-embryonated ova.

N
Diagnostic stage:
• un-fertilized ova, fertilized, or embryonated ova.
• Adult stage. embryonated ova
Fertile ova unfertile ova

N

N
Ancylostoma duodenale.
Nematoda.
Diagnostic stage : 4-8 cell embryonated ova.

N
Nematoda.
Diagnostic stage: D-shaped ova.

D-Shaped Ova

n
barrel shaped-egg with two polar plugs

N
Strongyloides stercoralis:
-Free-living Nematoda.
Diagnostic stage : Rhabditiform larvae in stool.