Microbiology

Question 1

Sexual transmitted infections caused by …………………….

Answer 1

Eight pathogens ; 4 are curable and 4 are incurable

Question 2

Mention the curable causes of STI

Answer 2

Baceterial and parasitic infections ;
BACTERIA : Gonorrhea , chlamydia and syphilis
PARASITE : Trichomoniasis

Question 3

Mention the incurable causes of STI ?

Answer 3

Viruses ; hepatitis B , HSV , HIV , HPV

Question 4

Mention the sexually transmitted infections ? And the eiologic organisms?

Answer 4

1) Chlamydial infection ;
2) Gonorrhoeal infection ; caused by Niesseria Gonorrhea
3) Syphilis ;
4) Trichomoniasis ;

Question 5

What is the most common STI and the second common STI ?

Answer 5

Most common is Chlamydial infection , Second most common is Gonorrhoeal infection

Question 6

Why is it hard to differentiate btwn Gonorrhoeal and Chlamydial STI ?

Answer 6

Because they have same risk factors and clinical presentation

Risk factors : Multiple sexual partners and unprotected sex
Clinical presentation:

Question 7

What is the incidence of gonorrhoeal infection btwn males and females?

Answer 7

Males (20-24) // Females ( 15-19 )

95% of infected males have symptoms. HOWEVER , 50% of infected females are asymptomatic

Question 8

Mention Gonorrhoea properties ?

Answer 8

1) Gram negative diplococci
2) Non- motile and non spore-forming
3) Not part of normal flora

Question 9

Mention the virulence factors of gonorrhea?

Answer 9

Pili and IgA proteases

Question 10

Incubation period is ……………………. And penetration period is ………………………..

Answer 10

(1-14) days // (1-2) days

Question 11

Routes of transmission of gonorrhea?

Answer 11

1) Contact with Penis , Vagina , Anus and Mouth ( Sexual intercourse )
NOTE : Ejaculation doesn’t have to occur for bacterial transmission, Contact is enough
2) infected mother to her newborn during childbirth

Question 12

How does sexually transmitted Gonorrheal infection manifests ?

Answer 12

White purulent discharge from the urethra due to neutrophilic response

Question 13

Define opthalmia neonatorum ?

Answer 13

A condition where the newborn has gonorrheal infection transmitted from infected mother

Question 14

How does opthalmia neonatorum manifest in newborns ?

Answer 14

1) Conjunctivitis that may cause blindness
2) Arthritis
3) life-threatening blood infection

Question 15

What is the only reservoir for gonorrhea?

Answer 15

Human only

Question 16

What are the targeted areas by gonorrhea ? And Mention the infection name .

Answer 16

Warm and moist areas of the body ;
Eyes : Opthalmia neonatorum
Throat : Pharyngitis
Urethra : Genitourinary tract infections
Anus : Rectal infection
Female reproductive system ( Vagina , cervix , uterus and fallopian tubes )
Blood : Disseminated gonococcal infection

Question 17

Gonococcal Genitourinary tract infection symptoms in males :

Answer 17

Firstly : Burning or painful sensation during urination
Others : 1) Frequency and urgency in urination 2) Swelling or redness at the opening of the penis 3) pus-like discharge from the penis. 4) Swelling or redness in the testicles

Question 18

What are the complications of gonorrheal GUT infection in males?

Answer 18

ACUTE COMPLICATIONS : Ascending infections and Infection of adjoining structures
CHRONIC COMPLICATIONS : Urethral stricture OR infertility
شيكي على هاي السلايدة بالمحاضرة

Question 19

Gonorrheal GUT infection symptoms in females :

Answer 19

1) Pain : when engaging in sexual intercourse or in the lower abdomin or during urination
2) Frequency and urgency urination
3) discharge from the vagina

Question 20

Gonorrheal GUT infection complications in females

Answer 20

1) Salpingitis ( Ascending infection to the uterine tubes )
2) Sterility
3) Ectopic pregnancy
4) Accessory glands infection ( Bartholin’s and skene’s glands )
5) Pelvic inflammatory disease
6) Fitz- Hugh-Curtis syndrome

Question 21

About Pelvic inflammatory disease ( PID ) : Symptoms and complications

Answer 21

SYMPTOMS : 1) Fever and leukocytosis 2) Severe abdominal pain. 3) Pelvic peritonitis and ascitis
4) lower abdomen and Adenxal tenderness 5) Irregular menstrual bleeding

COMPLICATIONS : infertility and ectopic pregnancy

Question 22

Gonococcal complications in pregnancy :

Answer 22

1) Preterm labour and delivery
2) Premature rupture of membranes
3) gestational bleeding
4) Postpartum endometritis

Question 23

Gonorrheal rectal infection ways of infection:

Answer 23

1) Rectal intercourse then common in males homosexuals
2) Females by contamination with infected vaginal discharge

Question 24

Gonorrheal rectal infection symptoms:

Answer 24

1) Tenesmus and constipation
2) Anal pain and pruritis
3) Rectal bleeding
4) Rectal purulent discharge

Question 25

Gonorrheal rectal infection is usually …………………………

Answer 25

Asymptomatic

Question 26

Gonorrheal pharyngitis way of infection :

Answer 26

Oral - genital contact

Question 27

Course of Gonorrheal pharyngitis :

Answer 27

Asymptomatic mimicking mild viral or streptococcal sore throat , resolve spontaneously

Question 28

Symptoms of gonorrheal conjunctivitis:

Answer 28

Lid Edema , lid erythema and marked purulent discharge

Question 29

Gonorrheal conjunctivitis is treated by :

Answer 29

Erythromycin ointment

Question 31

Disseminated Gonococcal infection manifests as :

Answer 31

Fever , bacteria , polyarthralgia THEN : 1) Arthritis 2) Synovitis 3) Dermatitis ( Skin pustules ) 4) Petechial rash

Question 32

Complications of disseminated Gonorrheal infection :

Answer 32

1) Meningitis 2) Endocarditis 3) Septic arthritis

Question 33

The most common cause of septic arthritis in sexually active adults is ………………………………..

Answer 33

Disseminated Gonorrheal infection

Question 34

For laboratory diagnosis , How are the specimens collected from both males and females ?

Answer 34

Females : Cervical swabs Males : Urethral exudate and urethral scraping شيكي على السلايدة مشان تشوفي الmilking وال scarping

Question 35

Morphology of gonorrhea by gram stain :

Answer 35

Polymorphs , Gram negative kidney shaped intracellular or extracellular diplococci

Question 36

Light microscopic appearance of gonorrhea :

Answer 36

Numerous neutrophils ( PMNs ) containing gram negative diplococci And this is diagnostic for males , for females positive culture is required.

Question 37

For Gonorrheal culture , What is the media used ?

Answer 37

It grows best under aerobic conditions , Most strains require CO2 also For non-selective media : Chocolate agar And Mueller-Hinton agar For selective media : Thayer Martin medium ( Martin Lewis agar ) with antibiotics ( V : Vancomycin , C : colistin , N : Nystatin )

Question 38

Colony morphology of gonorrhea :

Answer 38

Colonies are small, round,translucent, convex or slightly umbonate with finely granular margins and locate margins الدكتور قال مو حفظ

Question 39

Biochemical reactions of gonorrhea :

Answer 39

1) Oxidase positive 2) Glucose fermenters but not maltose والدكتور قال عنها مهمة

Question 40

What is the most method used for diagnosing Gonorrhea :

Answer 40

DNA Probes ; High sensitivity and specificity

Question 41

Treatment of Gonorrheal infection :

Answer 41

ALWAYS REMEMBER; GONORRHEAL WITH CHLAMYDIAL TREATMENT Gonorrhea : Ceftriaxone, IM OR Cefixime or ofloxacin or ciprofloxacin Chlamydia : Azithromycin OR doxycycline

Question 42

When to treat Gonorrheal infection ?

Answer 42

Symptomatic patients with urethritis , prostatitis and cervicitis

Question 43

The approach of prevention against gonorrhea :

Answer 43

1) Use of safety measures 2) Immediate treatment for symptomatic patients and their contacts

Question 44

Mention some safety measures :

Answer 44

1) Condom 2) Vaginal foam ( not reliable )

Question 45

Three of the nine species cause disease in humans. Mention them :

Answer 45

Chlamydia trachomatis , Chlamydophila pneumoniae , Chlamydophila psittaci

Question 46

Characteristics of C.trachomatis

Answer 46

1) Round cells 2) Oligate intacellular 3) lack the peptidoglycan layer

Question 47

What are the two forms of C. Trachomatis :

Answer 47

1) Elementary body 2) reticulate body

Question 48

Define the elementary body of:

Answer 48

Small , hardy , metabolically inert and infectious form

Question 49

Define the Reticulate body :

Answer 49

Large ( Star shaped ) , fragile , intacellular and replicative form

Answer 50

Large ( Star shaped ) , fragile , intacellular and replicative form

Question 51

Replicative cycle :

Answer 51

1) Elementary body attaches to unknown receptors on the plasma membrane of the epithelial tissue (Columnar or transitional epithelial cells ) 2) It enters the cell as endocytotic vacuole then begins the process of converting to the replicative RB 3) The reticulate body increases in number 4) Endosomal membrane expands by fusing with lipids of Golgi apparatus to form a large inclusion body 5) The RBs reorganise and condense to yield multiple EBs 6) The endosomal membrane then disintegrates or fuses with the host cell membrane releasing the EBs to infect the adjacent cells Note : it inhibits apoptosis of ECs thus enabling completion of its replicative cycle

Question 53

Target sits of C.trachomatis :

Answer 53

Conjunctiva and genital tract

Question 54

What are the reservoir of chlamydia :

Answer 54

Humans only

Question 55

What are the diseases caused by C. Trachomatis

Answer 55

1) Genital infections 2) Lymphogranuloma venerum 3) Reiter’s syndrome

Question 56

What are the genital infections caused by chlamydia in both males and females

Answer 56

Males : Urethritis and epididymitis Females : Cervicitis ( May produce vaginal discharge ) , salpingitis ( Ascending infection ; Saloingitis and pelvic inflammatory disease ) ) and urethritis

Question 57

Chronic or repeated infections of chlamydia :

Answer 57

Cause scarring that is an important cause of STERILITY AND ECTOPIC PREGNANCY

Question 58

What causes The lymphogranuloma venerum:

Answer 58

three strains of C.trachomatis – L1, L2, or L3.

Question 59

What is Lymphogranuloma venerum :

Answer 59

Small , transient , painless ulcer or papule which heals in a few days FOLLOWED BY multilocular suppurative involvement of inguinal lymph nodes

Question 60

What is the tirade of reiter’s syndrome

Answer 60

Reiters syndrome where you can’t see , you can’t pee and you can’t climb a tree Conjunctivitis ( Trachoma ) , Urethritis and reactive arthritis

Question 61

What are the organisms that cause reiters syndrome :

Answer 61

Chlamydia , salmonella, shigella , yersinia or campylobacter

Question 62

For chlamydia infection, specimens are detected from :

Answer 62

Males : Urethral scrapings Females : Cervical specimens

Question 63

The gold standard for chlamydial infection diagnosis :

Answer 63

Isolation of C.trachomatis by cell culture

Question 64

What are the most specific and most sensitive methods of diagnosis :

Answer 64

LCR , PCR LCR : ligase chain reaction PCR : polymerase chain reaction