Microbiology Flashcards
Sexual transmitted infections caused by …………………….
Eight pathogens ; 4 are curable and 4 are incurable
Mention the curable causes of STI
Baceterial and parasitic infections ;
BACTERIA : Gonorrhea , chlamydia and syphilis
PARASITE : Trichomoniasis
Mention the incurable causes of STI ?
Viruses ; hepatitis B , HSV , HIV , HPV
Mention the sexually transmitted infections ? And the eiologic organisms?
1) Chlamydial infection ;
2) Gonorrhoeal infection ; caused by Niesseria Gonorrhea
3) Syphilis ;
4) Trichomoniasis ;
What is the most common STI and the second common STI ?
Most common is Chlamydial infection , Second most common is Gonorrhoeal infection
Why is it hard to differentiate btwn Gonorrhoeal and Chlamydial STI ?
Because they have same risk factors and clinical presentation
Risk factors : Multiple sexual partners and unprotected sex
Clinical presentation:
What is the incidence of gonorrhoeal infection btwn males and females?
Males (20-24) // Females ( 15-19 )
95% of infected males have symptoms. HOWEVER , 50% of infected females are asymptomatic
Mention Gonorrhoea properties ?
1) Gram negative diplococci
2) Non- motile and non spore-forming
3) Not part of normal flora
Mention the virulence factors of gonorrhea?
Pili and IgA proteases
Incubation period is ……………………. And penetration period is ………………………..
(1-14) days // (1-2) days
Routes of transmission of gonorrhea?
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
How does sexually transmitted Gonorrheal infection manifests ?
White purulent discharge from the urethra due to neutrophilic response
Define opthalmia neonatorum ?
A condition where the newborn has gonorrheal infection transmitted from infected mother
How does opthalmia neonatorum manifest in newborns ?
1) Conjunctivitis that may cause blindness
2) Arthritis
3) life-threatening blood infection
What is the only reservoir for gonorrhea?
Human only
What are the targeted areas by gonorrhea ? And Mention the infection name .
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
Gonococcal Genitourinary tract infection symptoms in males :
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
What are the complications of gonorrheal GUT infection in males?
ACUTE COMPLICATIONS : Ascending infections and Infection of adjoining structures
CHRONIC COMPLICATIONS : Urethral stricture OR infertility
شيكي على هاي السلايدة بالمحاضرة
Gonorrheal GUT infection symptoms in females :
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
Gonorrheal GUT infection complications in females
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
About Pelvic inflammatory disease ( PID ) : Symptoms and complications
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
Gonococcal complications in pregnancy :
1) Preterm labour and delivery
2) Premature rupture of membranes
3) gestational bleeding
4) Postpartum endometritis
Gonorrheal rectal infection ways of infection:
1) Rectal intercourse then common in males homosexuals
2) Females by contamination with infected vaginal discharge
Gonorrheal rectal infection symptoms:
1) Tenesmus and constipation
2) Anal pain and pruritis
3) Rectal bleeding
4) Rectal purulent discharge
Gonorrheal rectal infection is usually …………………………
Asymptomatic
Gonorrheal pharyngitis way of infection :
Oral - genital contact
Course of Gonorrheal pharyngitis :
Asymptomatic mimicking mild viral or streptococcal sore throat , resolve spontaneously
Symptoms of gonorrheal conjunctivitis:
Lid Edema , lid erythema and marked purulent discharge
Gonorrheal conjunctivitis is treated by :
Erythromycin ointment
Disseminated Gonococcal infection manifests as :
Fever , bacteria , polyarthralgia
THEN :
1) Arthritis
2) Synovitis
3) Dermatitis ( Skin pustules )
4) Petechial rash
Complications of disseminated Gonorrheal infection :
1) Meningitis
2) Endocarditis
3) Septic arthritis
The most common cause of septic arthritis in sexually active adults is ………………………………..
Disseminated Gonorrheal infection
For laboratory diagnosis , How are the specimens collected from both males and females ?
Females : Cervical swabs
Males : Urethral exudate and urethral scraping
شيكي على السلايدة مشان تشوفي الmilking وال scarping
Morphology of gonorrhea by gram stain :
Polymorphs , Gram negative kidney shaped intracellular or extracellular diplococci
Light microscopic appearance of gonorrhea :
Numerous neutrophils ( PMNs ) containing gram negative diplococci And this is diagnostic for males , for females positive culture is required.
For Gonorrheal culture , What is the media used ?
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 )
Colony morphology of gonorrhea :
Colonies are small, round,translucent, convex or slightly umbonate with finely granular margins and locate margins
الدكتور قال مو حفظ
Biochemical reactions of gonorrhea :
1) Oxidase positive
2) Glucose fermenters but not maltose
والدكتور قال عنها مهمة
What is the most method used for diagnosing Gonorrhea :
DNA Probes ; High sensitivity and specificity
Treatment of Gonorrheal infection :
ALWAYS REMEMBER; GONORRHEAL WITH CHLAMYDIAL TREATMENT
Gonorrhea : Ceftriaxone, IM OR Cefixime or ofloxacin or ciprofloxacin
Chlamydia : Azithromycin OR doxycycline
When to treat Gonorrheal infection ?
Symptomatic patients with urethritis , prostatitis and cervicitis
The approach of prevention against gonorrhea :
1) Use of safety measures
2) Immediate treatment for symptomatic patients and their contacts
Mention some safety measures :
1) Condom
2) Vaginal foam ( not reliable )
Three of the nine species cause disease in humans. Mention them :
Chlamydia trachomatis , Chlamydophila pneumoniae , Chlamydophila psittaci
Characteristics of C.trachomatis
1) Round cells
2) Oligate intacellular
3) lack the peptidoglycan layer
What are the two forms of C. Trachomatis :
1) Elementary body
2) reticulate body
Define the elementary body of:
Small , hardy , metabolically inert and infectious form
Define the Reticulate body :
Large ( Star shaped ) , fragile , intacellular and replicative form
Large ( Star shaped ) , fragile , intacellular and replicative form
Replicative cycle :
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
Target sits of C.trachomatis :
Conjunctiva and genital tract
What are the reservoir of chlamydia :
Humans only
What are the diseases caused by C. Trachomatis
1) Genital infections
2) Lymphogranuloma venerum
3) Reiter’s syndrome
What are the genital infections caused by chlamydia in both males and females
Males : Urethritis and epididymitis
Females : Cervicitis ( May produce vaginal discharge ) , salpingitis ( Ascending infection ; Saloingitis and pelvic inflammatory disease ) ) and urethritis
Chronic or repeated infections of chlamydia :
Cause scarring that is an important cause of STERILITY AND ECTOPIC PREGNANCY
What causes The lymphogranuloma venerum:
three strains of C.trachomatis
– L1, L2, or L3.
What is Lymphogranuloma venerum :
Small , transient , painless ulcer or papule which heals in a few days FOLLOWED BY multilocular suppurative involvement of inguinal lymph nodes
What is the tirade of reiter’s syndrome
Reiters syndrome where you can’t see , you can’t pee and you can’t climb a tree
Conjunctivitis ( Trachoma ) , Urethritis and reactive arthritis
What are the organisms that cause reiters syndrome :
Chlamydia , salmonella, shigella , yersinia or campylobacter
For chlamydia infection, specimens are detected from :
Males : Urethral scrapings
Females : Cervical specimens
The gold standard for chlamydial infection diagnosis :
Isolation of C.trachomatis by cell culture
What are the most specific and most sensitive methods of diagnosis :
LCR , PCR
LCR : ligase chain reaction
PCR : polymerase chain reaction
