Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.
-
Upload
oswin-white -
Category
Documents
-
view
219 -
download
0
Transcript of Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.
![Page 1: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/1.jpg)
Swabs culture
Mrs. Dalia Kamal Eldien
Msc in Microbiology Lecture NO 11
![Page 2: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/2.jpg)
Objectives
Identify the different types of swabs Method of collection the swabLaboratory diagnosis of the different swab Case study of patient suffering from tonsillitisCase study of patient suffering from gas
gangrene
![Page 3: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/3.jpg)
Introduction
A swab can be taken from any area of the body that appears to have an infection. The microbiology laboratory attempt to culture (grow) a wide range of organisms (especially bacteria) from this sample, to determine which ‘germ’ is causing the infection.
Examples to the common swabs send to the microbiology lab Throat swab Nasal swab Eye swab Ear swab High vaginal swab Urethral swab Wound swab Skin swab
![Page 4: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/4.jpg)
Method of collection: A sterile cotton-wool swab, which is like an ear-bud, is
used to collect a small amount of fluid from a wound or surface.
By rolling the swab in affected area. The swab is transported in a special medium that
encourages growth of bacteria. For the throat swab In a good light and using the handle
of a spoon to depress the tongue, examine the inside of the mouth. Look for inflammation, and the presence of any membrane, exudate, or pus, Swab the affected area
![Page 5: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/5.jpg)
Swab
![Page 6: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/6.jpg)
Collection of throat swab
![Page 7: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/7.jpg)
Collection of Wound Swabs Gentle cleansing of a skin wound prior to sample collection
by sterile normal saline is recommended to reduce commensal flora.
Purulent exudates must be expressed onto swabs. Place the swab into the transport media.
Deep wound specimens (aspirates) are optimal as the predictive value of superficial swabs is low.
Investigation of deep wounds for anaerobes
![Page 8: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/8.jpg)
Collection of the wound swab
![Page 9: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/9.jpg)
Collection of Eye Swabs Collect before topical or anesthetics are applied. Swab pus or purulent discharge taken from the lower
inverted lid. Place the swab into the transport media. Collection of Ear Swabs Swab the external ear canal.
![Page 10: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/10.jpg)
Urethral swab: Express exudates from the urethra and collect it on a swab.
If exudate is unavailable, insert an urethrogenital swab about 2 cm into the urethra, gently rotate it and remove.
Place the swab into the transport medium. Vaginal swab Wipe away any excessive amount of secretion. Obtain secretions from the mucosal membrane with a swab. Place the swab into the transport medium.
![Page 11: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/11.jpg)
Collection of Vaginal swab
![Page 12: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/12.jpg)
Laboratory diagnosis
Specimen Processing Microbiologic testing should include both direct microscopic
examination and culture of the specimen. Clinical specimens should be inoculated onto both general
purpose and selective media to maximize bacterial recovery.
Common media used are: 2 blood agar(earobic& anearobic) MacConkey agar
![Page 13: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/13.jpg)
Special media Neomycin blood agar or kanamycin BA when anaerobic
bacteria is suspected Modified Tinsdale medium (MTM)or Tellurite blood agar
(TBA) When Corynediphtheriae suspected Crystal violet blood agar for streptococcus pyogen LJ for M. tuberculosis Modified New York City (MNYC) or Thayer Martin medium
isolating Nisseria gonorrhoeae Cooked meat medium (CMM)for Clostridium perfringens Sabroud dextrose agar(SDA) for fungi
![Page 14: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/14.jpg)
Bacterial Identification The first step in culture evaluation is the visual examination of
plated media. Most bacteria produce visible colonies in 24 hr, although some
require 48–72 hr. Inspection includes examination of colonial morphology, noting both types and numbers of colonies and any hemolytic reactions on blood-based agar.
Further classification is based on the presence or absence of growth on differential or selective media.
After the evaluation of plated media, examination of Gram stains made from each different colony type is performed.
Those reactions, combined with colonial morphology, may allow for the presumptive identification of organisms. If more than one colony type is present, subcultures of each are made.
![Page 15: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/15.jpg)
Several microbial identification systems are commercially available. Systems may be manual or automated.
![Page 16: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/16.jpg)
Antimicrobial sensitivity test: The agar disk diffusion method is more widely used for testing the
common, rapidly growing aerobic to facultative anaerobic pathogenic bacteria.
The Kirby-Bauer method is based on the diffusion of an antimicrobial agent impregnated within a paper disk through an agar medium. Briefly, a suspension of actively growing test organism is standardized to a turbidity equivalent to 0.5 on the McFarland scale. Within 15 min of standardization, a sterile swab is dipped into the bacterial suspension and a dry Müller-Hinton agar plate is inoculated by streaking the swab over the entire surface 3 times. To ensure an even distribution of the inoculum, the plate is rotated ~60° each time. Antimicrobial disks are placed on the plate and are gently pressed down to ensure their close contact with the agar surface. Inverted plates are placed in an incubator at 35°C. Plates are examined after 18 hr of incubation.
![Page 17: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/17.jpg)
Results: Zones of complete inhibition are measured in
millimeters using a ruler. The zone sizes around each drug are compared to those
published by the CLSI (Clinical and Laboratory Standards Institute ) in order to make an interpretation of susceptible, intermediate, or resistant for each agent tested.
![Page 18: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/18.jpg)
CASE STUDY (1)
A 5-year-old boy presented to the hospital suffering from acute malaise, shivering and vague pains in his legs, sore throat and had vomited twice. He was febrile (temperature 40.2°C) with a tachycardia . His pharynx, tonsils and buccal mucosa were red and inflamed and his tonsils were studded with white areas of exudate. He was diagnosed as having acute bacterial tonsillitis .proceed to identify the causative agent
![Page 19: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/19.jpg)
BLOOD AGAR
![Page 20: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/20.jpg)
Macconkey agar
![Page 21: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/21.jpg)
![Page 22: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/22.jpg)
![Page 23: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/23.jpg)
CASE STUDY (2)
• An 75-year-old diabetic man with swelling, blisters that contain gas bubbles near the area of infection, increased heart rate, and high fever. Skin in the affected area often turns from pale to brownish-red. Symptoms progress at a very rapid rate, the physician collect 2 wound swab and part of the necrotic tissue, proceed to identify the causative agent(s)
![Page 24: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/24.jpg)
DIRECT MICROSCOPICAL EXAM
![Page 25: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/25.jpg)
Blood agar and CMM
![Page 26: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/26.jpg)
Gram stain
![Page 27: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/27.jpg)
Gram stain
![Page 28: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/28.jpg)
?????
![Page 29: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/29.jpg)
Spore stain
![Page 30: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/30.jpg)
Nagler test
![Page 31: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/31.jpg)
Litmus milk reduction test
![Page 32: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/32.jpg)
Litmus milk reduction test
![Page 33: Swabs culture Mrs. Dalia Kamal Eldien Msc in Microbiology Lecture NO 11.](https://reader036.fdocuments.net/reader036/viewer/2022062322/5697c0021a28abf838cc31bb/html5/thumbnails/33.jpg)