Genital tract infection

Question 1

WHat are clinical indications of GTI?

Answer 1

Vag discharge, vaginitis/pruritus, suspected gonococcus candidasis, trichomoniasis, septic abortion, neonatal infection, puerperal sepsis, male urethral infection.

Question 2

How do Genital tract infections manifest?

Answer 2

Not just venereal (sexually transmitted) infections (STIs)- can have endogenous infection with normal flora, exogenous infections (usually sexually transmitted)

some high incidence diseases are gonococcal and chlamydial infections- most common reportable diseases

vaginitis and vaginosis is the second most frequent outpatient microbio investigation

Question 3

What are the main bacterial STIs that cause Gonorrhoea and PID, syphilis, chancroid, PID, lymphogranuloma venereum

Answer 3

Neiserria gonorrhoea causes gonorrhoea and PID, syphilis is caused by Treponema pallidum,
chancroid by Haemophilus ducreyi,
PID is caused by Chlamydia trachomatis, mycoplasma hominus, mycoplasma genitalium, ureaplasma urealyticum
lymphogranuloma venereum by chlamydia trachomatis

Question 4

What are the main viral STIs that cause AIDS (acquired immuno deficiency syndrome), genital herpes, genital warts, hepatitis

Answer 4

AIDS caused by HIV (immunodeficiency virus), genital herpes caused by herpes simplex virus II (HSV II) is 60-70%, by HSV I 30-40%
genital warts caused by human papilloma virus (HPV 6 and 11)
hepatitis caused by Hepatitis B virus (main), Hep c, Hep D

Question 5

What are the main parasitic STIs that cause public lice , scabies, trichomoniasis

Answer 5

Crabs caused by Phthirus pubis, scabies caused by Sarcoptes scabiei and trichomoniasis by trichomonas vaginalis

Question 6

WHat are the female and male swabs and fluids for genital specimen? what organism requires charcoal transport media? which one does viruses need?

Answer 6

F: vulval, vaginal (HVS), cervical (ECS), urethral, rectal
M: urethral swab and smear, prostatic fluid, rectal
Neiserria gonorrhoea needs charchoal transport media, viruses - Hanks balanced salt solution

aspirates include pus samples for anaerobic culture for upper GTI, blood (serum) for syphilis, first void urine for Neiserria and chlamydia PCR, parasites in specimen jar

Question 7

which swabs may be dry? What swabs recommended for bacteria and virus?
what can possibly inhibit bacteria ad viruses and PCRs

Answer 7

Chlamydia and gonorrhoea (dry so not suited for MC+S) PCR. Cotton, Rayon, Dacron
Calcium alginate can inhibit
Wooden tip swabs not suitable f0r viruses as contain toxins and formaldehyde

Question 8

what is GC/TM/NYC agar used for?
what is SAB/Chromogenic candida used for?
What is used to ID strep agalactiae
what is A7 agar used for?

Answer 8

1. for N gonorrhoea
2. SAB for yeast
3. Granada medium, Chromogenic STB, carrot broth, lim broth
4. a7 for mycoplasma hominis and ureaplasma urealyticum

Question 9

why is selective and differential media used for GNC?

Answer 9

So Neiserria can grow with minimum growth of NF and yeast

Question 10

How does Thayer Martin- choc agar work

Answer 10

Thayer Martin - Chocolate agar with
- Isovitalex (Vitox)
- Vancomycin, colistin, nystatin- vancomycin inhibits gram pos, colistin inhibit gram neg, nystatin inhibits yeast moulds fungi
- + trimethoprim (Modified Thayer Martin)- prevent swarming proteus

Question 11

How does NYC- lysed HBA work/what it contains

Answer 11

Yeast autolysate
- Vancomycin, colistin, amphoteracin B - + ,
vanco inhibits gram pos, colistin inhibits gram neg, amp B inhibits yeast, fungi, moulds
trimethoprim prevent swarming proteus

Question 12

What does GC medium have- lysed horse blood use?

Answer 12

Yeast autolysate
- Lincomycin, colistin, amphoteracin B + trimethoprim, lincomycin inhibit gram pos, colistin inhibit gram neg amp B inhibit yeast fungi moulds
- Some strains of N. gonorrhoeae are sensitive to Vancomycin (TM and NYC medium)

Question 13

What media should we use to culture vaginal discharge?

Answer 13

CHOC (48hr in CO2), and or GC/NYC/TM- also 48 in co2
BA, CNA? MAC/BA?
a quarter SAB and or chromogenic candida plate
Feinberg-Whittington (FW) broth (min 48h incubation) if Trichomonas PCR unavailable (urine or swab) - Anaerobic culture + MTZ (if Gram indicates polymicrobial picture)
- Two Sabouraud’s fungal slopes if indicated (37degrees C+RT)

Question 14

What media is needed for an obstetric screen and or if STB (strep B) screen requested

Answer 14

1/4 granada medium/Lims broth for s. agalacticae

Question 15

What media is needed for post partum pyrexia (fever), abortion or IUD or retained Tampon?

Answer 15

All the primary media listed above but ensure anaerobic culture performed
- Blood agar + metronidazole disc (AnO2) and/or LBAG + metronidazole disc - RCMB (Robertson’s cooked meat broth- anaerobic)

Question 16

what media is needed for male urethra swabs?

Answer 16

CHOC and or TM GC NYC and BA

Question 17

How can you process wet preps microscopically (reporting)

Answer 17

Wet preps distinguish between normal and abnormal, prep from swab after culture and gram smear
- report for Trichomonas vaginalis (+/occasional, up to +++ OR NOT SEEN)
yeast report same way - NOT SEEN (look for psuedohypae and budding)
epithelial cells covered with many bacteria- clue cells (vaginosis)
May or may not report on leucocytes and RBCs

Question 18

How to process GRAM microscopy?

Answer 18

report presence of:
- Epithelial cells
- Leucocytes
- Yeast cells and mycelium - Lactobacilli (GBP)
- Other bacteria, especially resembling
* Neisseria gonorrhoeae (GNIDC)
* Anaerobic picture ± vaginosis
- Clue cells (vaginosis)

Report the absence of yeast if not already annotated with wet mount

Question 19

what are clue cells and what is associated with it? what else might you see in gram microscopy?

Answer 19

Clue cells - epithelial cells covered with Gram variable cocco/bacilli - Associated with vaginosis (No leucocytes)
- Epithelial cells covered with lactobacilli – normal
* GNIDC – Gram negative intracellular diplococci
* Yeast - budding yeast, pseudohyphae
* Anaerobes – polymicrobial without clue cells
- and/or if specific anaerobic forms seen

Question 20

Is bacteria vaginosis likely an exo or endogenous infection? what are the characteristics regarding discharge (colour), smell, presence of cells, symptoms?

Answer 20

Likely endogenous infection
- Malodorous vaginal discharge pH >4.5
* Fishy odour, “Whiff” test (10% KOH)
* Thin, grey-green discharge
* Presence of “clue” cells
- No inflammation (no WBCs)
- Little to no discomfort

Question 21

When does bacterial vaginosis occur relating to PH?

Answer 21

Normal lactobacilli prod lactic acid which maintains pH to 4, so bacterial vaginosis happens when pH rises

Question 22

WHat is the significance of bacterial vaginosis?

Answer 22

• Increase risk of PID (UGTI) and cause of post op infections - Risk of endometrial infection
• ? Role in pregnancy
• Premature rupture of membranes
• Pre-term labour
• Post-partum infection

Question 23

what is the normal chemical processes of lactobacilli producing lactic acid and vaginosis producing fishy odour?

Answer 23

Normal lactobacilli–>glycogen (polymer glucose)–>glucose–>Lactic acid (pH 4.0)
normal lactobacilli also produce bacteriocins and peroxide
Vaginosis: decrease lactate increased succinate increased acetate increased amines –>fishy odour (elevated pH)

Question 24

What bacteria is vaginosis associated with?

what are general characteristics of G. vaginalis, bacteroides, peptostreptococcus, mobiluncus, mycoplasma hominis, ureaplasma urealyticum

Answer 24

Gardnerella vaginalis, “Clue” cells have been shown to be covered with Gardnerella
research shows multiple bacteria can be involved
Gardnerella vaginalis - Gram Variable – GNB, Faculative
Bacteroides sp. - GNB AnO2
Peptostreptococcus sp. - GPC AnO2
Mobiluncus sp. - GNHB AnO2- curved gram neg b
Mycoplasma hominis - No cell wall – membrane - GN
Ureaplasma urealyticum- No cell wall – membrane - GN

Question 25

what is vaginitis? what are its symptoms and characteristics?

Answer 25

Inflammation of vaginal mucosa symptoms= Abnormal discharge * Offensive odour * Itching - Leucocytes

Question 26

what is vaginitis commonly caused by?

Answer 26

Trichomonas vaginalis, candida albicans and candida sp- can ID by germ tube for c albicans, colony morph and chromogenic media

Question 27

1. What are trichomonas vaginalis and what symptom do they cause in vaginitis? 2. When do they multiply and how long do they survive in a host? 3. How are they seen in wet preps? 4. how can we test for their presence 5. what do we treat it with?

Answer 27

1. Flagellated protozoan (no known cyst form) Causes smelly, yellow-green vaginal discharge 2. Multiplies when pH becomes more basic than normal (3.8-4.2) and can survive in host for 2 years 3. seen as motile trophozoite 4. Can test by PCR on first void urine or urethral swab - if no PCR use Feinberg Whittington broth to improve ID- promotes maintains growth, incubation 5-28 days 5. treat with MTZ (flagyl)

Question 28

how does t. vaginalis reproduce and what are the diagnostic and infective stages what is the definitive host?

Answer 28

multiply by longitudinal binary fission, infective stage is when trophozoite in vag or orifice or urethra (exchange between people) diagnostic when trophozoite in vag and prostatic secretions and urine humans are the definitive host

Question 29

What are characteristics of yeast in gram stain

Answer 29

gram pos (purple) pseudohyphae, blastospores

Question 30

What are the characteristics of Chlamydia trachomatis? can you culture them?

Answer 30

Very small, obligate intracellular bacteria (once considered a virus) Cell wall is similar to that of Gram-neg and cannot culture them

Question 31

What are the type of Chlamydia trachomatis which cause trachoma (eye infection) STDs (NSU and PID) LGV- Lymphogranuloma Venereum (ulcers on genitalia localise in the inguinal lymph nodes)

Answer 31

A-C -Trachoma D-K - STDs (NSU non-specific urethritis often with N. gonorrhoeae +++ mucopurulent discharge and PID) L1-3 LGV

Question 32

How can Chlamydia trachomatis be detected and treated

Answer 32

Organism can be detected in epithelial cells (urethra + cervix) and first drops of urine - PCR methods - very sensitive - Test often requested with concurrent request for N. gonorrhoeae PCR and/or MC+S Treatment - Tetracycline, Ciprofloxacin

Question 33

what is the life cycle of chlamydia?

Answer 33

1. The elementary body (infectious particle) enters host cell 2. EB transforms to reticulate body (reproducible element) inside and replicates 3. Inside the cell still the replicated RB transforms to elementary bodies 4. cell lyses and EB burst out of it

Question 34

Is N. gonorrhoea NF? what does it cause?

Answer 34

Strict human pathogen - NOT normal flora causes Gonorrhoea - Pyogenic (pus producing) infection of urethra (urethritis) and uterine cervix

Question 35

In which disease can 50% of females be asymptomatic ( decrease sensitivity Gram stain) - 2.5-5% of men may be asymptomatic?

Answer 35

Gonorrhoea

Question 36

what can complications of both sexes be for gonorrhoea? what about in women? what about men and neonates?

Answer 36

Disseminated gonococcal infection (0.5-3%) * Bacteraemia, Meningitis, Arthritis, Skin pustules Women: PID (also by C. trachomatis) - Infection of uterus, fallopian tubes where Acute salpingitis is inflammation of uterine tube or fallopian tubes - Resulting tissue damage can lead to infertility and increase risk of ectopic pregnancy. Men - Epididymitis (testes) - Prostatitis * Neonates- Gonococcal ophthalmic neonatorum (conjunctivitis) - Neonatal pharyngitis

Question 37

what are pathogenic Neiserria sp lab characteristics? cat, ox, optimal growth conditions, for CHO fermentation CTA- cystine triple agar sugars what is the basis? What is the natural habitat in host?

Answer 37

GN diplococci (pairs) Kidney bean shaped with adjacent sides flattened - Clinical smears - seen intracellularly within PMN - GNIDC, Oxidase +, Catalase + Optimal growth 35-37 ̊C * Natural habitat is mucous membranes of host, rapidly die outside the human body * Prefer CO2 and moisture CTA- Relies on preformed enzymes - need heavy inoculum.Phenol red = indicator (alk=red, acid=yellow)- only yellow at tope of tube as OBLIGATE aerobe

Question 38

What are the virulence factors of N gonorrhoea? (7)

Answer 38

1. Endotoxin activity, 2. lipo-oligosaccharides, 3. IgA1 protease, 4. Pili (fimbriae), 5. plasmids, 6. chromosomally mediated resistance, 7. outer membrane proteins Endotoxin activity Gram Neg cell wall (no exotoxins) Lipo-oligosaccharides - adherence, lysis of PMN & epithelial cells, stimulate TNFa (leads to tissue damage-spreading factor) Pili- attachment to mucosal surfaces - Five colony types T1, T2, T3, T4, (? T5) T1 and T2 piliated -virulent(small,shiny raised colonies) * T3-T5 non-piliated, avirulent(large flat colonies) Plasmids - confer antimicrobial resistance - Penicillin (penicillinase producing strains PPNG) - Tetracycline (TRNG) Outer membrane proteins - Variety of proteins with a variety of functions including: * Enhanced mucosal cell invasion ,Confer resistance to bactericidal effects of normal serum

Question 39

GNC/GNDC and/or GNIDC - especially from a uro-genital site - Reliable in males (98%), 50-70% in females * Doesn’t usually grow on BA initial culture - Cystine trypticase agar (CTA) sugars - Attacks glucose only - ? Confirmation of carbohydrate results by API due to variants of other species having GLU only pos result or MALDI-TOF * RapID NH, API NH, others - biochemical tests/ enzyme substrates (2-4 hrs) PCR and molecular methods on first void urine or dry urethral swab

Answer 39

Neiserria gonorrhoea

Question 40

how do we treat N gonorrhoea?

Answer 40

inc resistance to penicillin (Penicillinase Producing N.gonorrhoeae -PPNG) inc R to fluoroquinolones=Ciprofloxacin 500 mg orally, ofloxacin, or levofloxacin cephalosporins Ceftriaxone (IM), Cefixime (oral) but inc R means ceftriaxone used more CDC Recommendation for uncomplicated infection of pharynx, cervix, urethra, rectum is Ceftriaxone Spectinomycin single 2g,(IM) dose - Traditionally used for strains that were resistant to oral antibiotics

Question 41

What does H ducreyi (small GN coccobacillus like others in genus) cause? how is it spread? where is it common? what is the only known reservoir

Answer 41

only known reservoir= humans, punched out ulcer, some women asymptom carrier causes genital ulcers (soft sore/chancoid) which appear 4-10days after contact (last 1-35 days), ulcers usually affect skin prone to friction in sex, Lesions can be deep with purulent exudate at base, bleed easily and very painful - If left untreated, ~50% of cases spread to inguinal lymph nodes leading to hard, painful lumps (buboes) - Responsible for 20-60% of genital ulcers in parts of Africa, Asia and Latin America * Can also cause non-sexually transmitted skin lesions

Question 42

Diagnosis * Presence of one or more painful ulcers ± lymphadenopathy * Exclusion of syphilis, herpes simplex (I and II), LGV * Sensitivity of culture is between 60-80% (very fastidious requirements) - Swabs in transport media must arrive at lab < 4 hours - Requires X factor * Detection of typical GNB morphology in specimen - Sensitivity (5% to 63%) and specificity (51% to 99%) * PCR has high sensitivity (>95%) and specificity (99%), if available GNB like school of fish- elongated chains/group and slightly yellow adherent colonies, culture needs v specialised media

Answer 42

Haemophilus ducreyi

Question 43

What is known as the flesh eating STI? what does it cause and past names. where is it more common?

Answer 43

Granuloma venereum/inguinale Ulcers (primarily genital) caused by Klebsiella granulomatis- Taxonomic name change from Calymmatobacterium granulomatis Historically called Donovanosis * Donovan bodies (organisms) can be seen inside macrophages tropical and subtropical countries (incl central Australia) Painless nodules appear from a few days up to a year after contact, break open leading to fleshy red ulcers (bleed on contact) Organisms can spread from the open lesions and will mutilate (eat tissue)- * Can lead to cancer

Question 44

Diagnosis - cannot be grown on routine culture media - Can be cultivated in human blood monocytes or epithelial cell lines - Diagnosis can be made by histology/cytology of a biopsy or smear from the lesion- PCR is preferred if available Must be a dry swab (no transport media) or test biopsy material * Keep samples cool (4 ̊C) how can you treat it?

Answer 44

Granuloma venereum- see macrophage w donovan bodies Doxycycline for ≥21 days, SXT ≥21 days, CIP ≥21 days, Erythromycin ≥21 days - Possible relapse of infection after successful Tx at around18 months

Question 45

How can strep agalactiae be involved in GTIs? how can it affect neonates? what are the early and late onset consequences. what other group of people is it opportunistic in? what infections does group b strep cause?

Answer 45

NF in URT also primary reservoir in gastroint tract, 10-35% women carry it vaginally Opportunistic - Neonates acquire in utero before delivery, during birth or after birth * 1in2 infants from colonised mothers become colonised Early onset - Septicaemia, pneumonia, meningitis * Late onset - Bacteraemia, meningitis we do screening for group B strep in pregnant women prior to delivery Patients with carcinomas and/or debilitating disease * Including diabetes, liver cirrhosis, stroke, neoplasia Infections - Cellulitis, abscesses, otitis media - Endocarditis, meningitis, septicaemia

Question 46

compare early and late onset in terms of: onset, risk factors,mode of acquisition, symptoms, mortality, post infection sequelae

Answer 46

EO- birth to 5 days after, LO 7 days g3 months after birth EO has maternal complications during delivery - prolonged rupture of membranes, fever, preterm labour while LO has none ID EO has vertical transmission as mode of onset LO- nosocomial or at home EO has pneumonia,bacteraemia, septic shock, and meningitis. LO= bacteraemia, meningitis EO has mortality higher 2-8% higher in pre-term babies related to birth weight. LO= 10-15% EO sequelae is neurological damage, LO has 50% of survivors

Question 47

WHat are the virulence factors of group B strep? (4)

Answer 47

Capsular polysaccharide antigens, enzymes (hyaluronidase- spreading factor to invade CT and CD5a peptidase), B haemolysin, lipoteichoic acid (adherence)

Question 48

How does B haemolysin contribute to virulence in s agalactiae

Answer 48

contributes to Pore-forming haemolysis - Studies have shown activity against alveolar lung tissue & endothelial cells - Activity against endothelial cells of CNS - Induces apoptosis of liver cells

Question 49

S agalactiae lab characteristics what to treat it with?

Answer 49

lancefield group B, large colony narrow B haemolysis (rarely non haemolytis), bile tolerant- weak small colonies on MAC LF pink orange on granada, pink red on ChromID Strepto B medium (STRB) pos CAMP test, hippurate pos treat with penicillin first choice som R to erythromycin and clindamycin. can also use AMP, cefotaxime CTX, ceftriaxone

Question 50

How does hippurate hydrolysis work?

Answer 50

Hippuric acid with the help of hippuricase in 2 hrs min will turn to Na benzoate and glycine. glycine will react with ninhydrin (reagent) to form NH3 and CO2 and residual ninhydrin so there is purple colour

Question 51

how can you use CAMP test for s agalactiae?

Answer 51

pos= arrow head produced by B haemolysis, overnight at 35 degrees- staph and strep haemolysin enhanced area of haemolysis

Question 52

how does lims broth and carrot both compare for s agalactiae

Answer 52

LB for colonies enriched by selection by GPC, CB is indicator media swab goes into both CB is selective and diff, lims broth enriched and colistin and nalidixic acid (inhibits gram neg) LB incubate at 37 overnight while CB also 37 but not overnight with LB after need to subculture to BA and incubate overnight while CB turns bright orange red after 16hrs for maj of strains then for LB you ID by colony morph and group B antigen, CB you subculture any negatives

Question 53

what colour is s agalactiae, e coli, enterococcus faecalis on new granada medium?

Answer 53

group B= orange, e coli= bit yello tint, e faecalis is white

Question 54

how can we prevent GBS infection for babies?

Answer 54

Administer antibiotics to colonised pregnant women Administer antibiotics to pregnant women with risk factors (like past infact w gbs, premature birth) Give antimicrobial prophylaxis to newborns

Question 55

Where is Listeria sp naturally found and isolated?

Answer 55

Found in the environment (vegetation, water and soil) - Isolated from animals as commensals (faecal flora) and pathogens

Question 56

Which listeria sp is the most recognised pathogen in human and animal with 1-10% humans carrying it in the bowel after ingestion when can you get outbreaks? who does it primarily affect? how can it be prevented?

Answer 56

L. monocytogenes outbreaks following ingestion of contaminated food products ham etc primarily affect pregnant women, immunocompromised, newborns- Pregnant women may be asymptomatic or have flu like symptoms with/without vaginal discharge * Infants can acquire in utero or during birth, often leads to septicaemia and meningitis * 5th most common cause of meningitis * 2nd most common cause of meningitis in babies and >60 years old by having health campaigns for pregnant women, proper food prep and handling (contam after processing before packaging)

Question 57

Which diseases are caused by Listeria monocytogenes how is early onset and late onset acquired in babies?and what is l monocytogenes causing in babies

Answer 57

Symptoms of acute listeriosis - Days to weeks after initial exposure - Flu like illness - fever, myalgia, sore throat, malaise - Possible diarrhoea and vomiting - Septicaemia – fever, chills, hypotension, tachycardia - CNS involvement - meningitis * Headache, stiff neck, confusion, loss of balance, or convulsions Pregnancy - Mother * May be asymptomatic (other wise as above) * May have a vaginal discharge - Can lead to miscarriage or stillbirth - Premature birth - Infection of the newborn - Foetus/newborn * Early onset-acquired through placental circulation * Lateonset-vertical transmission during birth * Septicaemia/meningitis * Fever, irritability, pustular skin lesions, bulging fontanelles

Question 58

what is the infectious dose of L monocytogenes in immunocompetent and high risk individuals

Answer 58

10^7 to 10^9 cfu in immunocompetent 10^5 to 10^7 cfu in high-risk individuals (takes less cfu in high risk individuals)

Question 59

What are the virulence factors of L monocytogenes?

Answer 59

-Growth at a low pH in food and GIT - Growth/survival at a high osmolality (salt cured foods) - Compete with NF in GIT for nutrients - Production of bacteriocins - Growth/survival at low temperatures - Efflux pump - resistance to disinfectants - Biofilm production Enable the organism to cross GIT into blood - Enable invasion and proliferation inside both phagocytic and non- phagocytic cells plus cell-to-cell transfer

Question 60

What is l monocytogenes lab characteristics? motility differs by temperatures... what temp is it also able to grow and does it grow on MAC while agar produces blue colonies w white halo for it

Answer 60

SHORT non spore GPB may resemble strep, in PAIRS-coccobacillary and palisading small grey white moist on BA- narrow zone B haemolysis, cat pos tumbling motility at 25 non motile at 37 degrees Aesculin and hippurate + (same as Gp B Strep) * Grows at 4oC - important characteristic for pathogenesis and epidemiology * Needs enrichment (BA or CHOC) – NO GROWTH on MAC * Chromagar (Listeria) - blue colonies with a white halo

Question 61

what does mycobacterium hominis cause?

Answer 61

pelvic inflammation, pyelonepritis, post partum fever/abortion

Question 62

What is A7 agar use to grow and what does it contain?

Answer 62

Contains lots of growth factors (no cells) - serum, peptones, yeast extract, vitamins Urea in there to grow Ureaplasma urealyticum and Arginine used to grow Mycoplasma hominis U. urealyticum has black colonies with a sea urchin edge mycoplasma V small on agar

Question 63

* Smallest prokaryotes capable of self replication * No cell wall * All are capnophiles (if cultivatable, 5 days in 5% CO2 on A7 agar, otherwise test by PCR) * Multiple species are considered to be commensals of the urogenital tract * Mycoplasma hominis and Ureaplasma urealyticum are the most frequently encountered causes of infection * Mycoplasma genitalium is an emerging pathogen – ID by PCR - Can cause PID, urethritis and spontaneous abortion - Concern over antibiotic resistance

Answer 63

Mycoplasma and Ureaplasma