GUM Flashcards
1
Q
What type of virus is HPV?
A
Double-stranded DNA virus
2
Q
What proportion of PID cases are caused by CT?
A
14-35%
3
Q
What is the estimated transmission risk of CT with a single episode of UPSI?
A
10%
4
Q
What proportion of women with CT will develop SARA?
A
<1%
5
Q
What proportion of patients with untreated CT will spontaneously clear by 12 months?
A
50%
6
Q
What are rates of concordance when one partner is diagnosed with CT?
A
75%
7
Q
What is the first-line management of uncomplicated CT?
A
Doxycycline 100mg bd for seven days
or
Azithromycin 1g orally as a single dose, followed by 500mg once daily for two days
8
Q
If first line management options are contraindicated in CT, what should be used instead?
A
Erythromycin 500mg bd for 10–14 days
or
Ofloxacin 200mg bd or 400mg od for seven days
9
Q
What are the management options for uncomplicated CT in pregnancy?
A
Azithromycin 1g orally as a single dose, followed by 500mg once daily for two days
or
Erythromycin 500mg four times daily for seven days
or
Erythromycin 500mg twice daily for 14 days
or
Amoxicillin 500mg three times a day for seven days
10
Q
In whom should a TOC be performed for re: CT?
A
- Pregnancy
- Where poor compliance is suspected
- Where symptoms persist
11
Q
Co-infection of M.gen is reported in what proportion of CT infections?
A
3%-15%
12
Q
What type of bacteria is chlamydia trachomatis?
A
Gram negative
13
Q
How does chlamydia trachomatis replicate?
A
WITHIN a cell
14
Q
Which CT serovars account for trachoma?
A
A-C
15
Q
Which CT serovars account for genital infection?
A
D-K
16
Q
Which CT serovars account for LGV?
A
L1-L3
17
Q
What is the lifecycle of CT?
A
Elementary bodies (EB) are the infectious forms of CT and are spore like structures with a hard cell wall allowing its survival in the environment outside the cell.
They are 200-400 nanometres in size.
An EB attaches to the new host cell and enters the cytoplasm surrounded by a vacuole called an inclusion.
Within this inclusion, the EB transforms into a Reticulate body (RB) and rapidly replicates by binary fission.
RB’s transform back into EB’s with increasing expansion of the inclusion within the host cell cytoplasm.
The host cell ruptures causing expulsion and release of the EB’s into the environment before they re-infect further epithelial cells.
18
Q
What are the risks of CT in a pregnant pt?
A
- Neonatal conjunctivitis
- Pre-term labour
18
Q
Where is LGV endemic?
A
Southern Africa, West Africa, Madagascar, India, South-East Asia and the Caribbean
18
Q
What is the most common serovar of CT associated with LGV infection?
A
L2
19
Q
What is the incubation period of LGV?
A
3-30 days
20
Q
What is the primary manifestation of LGV in MSM?
A
Haemorrhagic proctitis - 96% of cases in Western Europe
21
Q
Can LGV cause systemic symptoms?
A
Yes - fever and malaise
22
Q
What is ‘groove’ sign in LGV?
A
When both inguinal and femoral lymph nodes are involved, they may be separated by the so-called ‘‘groove sign,’’ which consists of the separation of these two lymph node systems by the inguinal ligament
23
What proportion of LGV cases display 'groove sign'?
15-20% (although considered pathognomonic of LGV)
24
What are the long-term consequences of LGV?
Destruction of LNs may result in genital lymphoedema (elephantiasis) with persistent suppuration and pyoderma
Chronic inflammation and destruction of tissue may lead to proctitis, proctocolitis mimicking Crohn’s disease, fistulae, strictures and chronic granulomatous disfiguring fibrosis and scarring of the vulva with esthiomene (Greek word meaning ‘‘eating away’’). All more frequent in women, reflecting the involvement of retroperitoneal lymphatics.
25
What may be seen on microscopy in LGV?
Rectal polymorphonuclear leucocytes (PMNLs) from rectal swabs is predictive of LGV proctitis, especially in HIV-positive MSM, with levels of >10 and >20 PMNLs per high-power field both shown to be significant
26
How is LGV treated?
Doxycycline 100 mg twice daily orally for 21 days
2nd choice: erythromycin 500mg four times daily orally for 21 days
27
What is the 'look-back' period for LGV?
4 weeks prior to the patient’s symptoms, or the last 3/12 if asymptomatic LGV is detected
28
If TOC required in LGV (e.g. if pregnant), when can it be performed?
2 weeks after treatment
29
Who is most likely to be diagnosed with LGV in the UK?
HIV +ve MSM
30
What is the smallest known smallest known self-replicating bacterium?
M.gen
31
What is the 2nd most common cause of NGU?
M.gen
32
Whom should be tested for M.gen
Recommend testing:
- NGU
- PID
Consider:
- Muco-purulent cervicitis +/- PCB
- Epididymitis
- Sexually-acquired proctitis
33
In whom should a TOC be performed in M.gen?
All patients
34
What is the treatment for uncomplicated M.gen (urethritis/cervicitis)?
Doxycycline 100mg bd for seven days followed by azithromycin 1g orally as a single dose then 500mg orally once daily for 2 days where organism is known to be macrolide-sensitive or where resistance status is unknown
Moxifloxacin 400mg orally once daily for 7 days if organism known to be macrolide-resistant or where treatment with azithromycin has failed
35
What is the treatment for complicated M.gen (PID/EO)?
Moxifloxacin 400mg orally once daily for 14 days
36
How is M.gen treated in pregnancy?
A three-day course of azithromycin can be used for uncomplicated M. genitalium infection detected in pregnancy
37
What is the partner treatment for M.gen?
Only current partner(s) (including non-regular partners where there is likely to be further sexual contact) should be tested and treated if positive
38
How is NGU diagnosed?
Confirmed by demonstrating five or more PMNLs per high power (x1000) microscopic field (averaged over five fields) on a smear obtained from the anterior urethra
Sampling with a 5-mm plastic loop or cotton tipped swab which should be introduced about 1cm into the urethra. A 5-mm plastic loop is less painful than a Dacron swab which is less painful than a Rayon swab
38
What is the most common cause of NGU?
C. trachomatis
39
What is the recommended 1st line treatment for NGU?
Doxycycline 100mg twice daily for 7 days
40
What are the alternative treatments for NGU?
Azithromycin 1g stat then 500mg once daily for the next 2 days (three days total treatment)
or
Ofloxacin 200mg twice daily, or 400mg once daily, for 7 days
41
For how long should people abstain in NGU?
14 days from start of treatment
42
What proportion of patients experience persistent NGU?
15-25%
43
What is recurrent NGU?
Symptomatic urethritis occurring 30-90 days following treatment of acute NGU
44
In what proportion does recurrent NGU occur?
10-20%
45
What is the positive predictive value of clinical Dx PID (compared to laparoscopic diagnosis)?
65-90%
46
What is the negative/positive predictive value of endocervical pus cells for PID?
Negative predictive value - 95%
Positive predictive value - 17%
47
What is the 'lock-back' period with PID?
6 months
48
What is scabies caused?
Sarcoptes scabiei var hominis
49
How long is the life cycle of Sarcoptes scabiei?
4-6 weeks
50
How long is the 'moulting' period in scabies (eff to adult)?
10-15 days
51
How long can scabies live off a host?
24-36 hours
52
What type of hypersensitivity reaction causes itching in scabies?
Delayed type-IV hypersensitivity
53
How soon do scabies symptoms start?
Symptoms begin 3-6 weeks after primary infestation, but occurs earlier at 1-3 days in a reinfested person probably due to prior sensitization to the mite and mite products
Scabies is
therefore infectious before the rash develops
54
What proportion of crusted scabies cases has no identifiable risk factor, e.g. immunocompromise?
40%
55
What are the treatment options for scabies?
- Permethrin 5% cream
- Malathion 0.5% aqueous lotion
- Ivermectin
56
After how long should permethrin be washed off?
8-12 hours
57
After how long should malathion be washed off?
24 hours
58
How long may post-scabetic itch last?
2 weeks
59
Where do scabies live on the skin?
The mites burrow into the upper layer of the skin but never below the stratum corneum
60
How many eggs per day do scabies lay?
2-3/day
Scabies may live for 1-2 months, and 10% of her her eggs survive
61
What type of organism is MC?
A large DNA
virus
Molluscum contagiosum belongs to the Poxviridae
family and Molluscipox genus
62
How many subtypes of MC are there?
4
63
What are the most common subtypes of MC?
MC-1 - most prevalent
MC-2 - relatively commoner in immunocompromise/HIV, and with increasing age and thus genital infection
64
By when does MC usually spontaneously resolve?
12-18 months
65
How can MC in severe immunocompromise (e.g. HIV) present?
Molluscum
lesions can affect the eyelids and cause chronic conjunctivitis due to a FB-type reaction
66
What type of virus is the poxvirus?
Double-stranded DNA viruses
67
What is the definition of recurrent VVC (thrush)?
At least four episodes per 12 months with two episodes confirmed by microscopy or culture when
symptomatic (at least one must be culture)
68
Do male partners require treatment when a woman has been diagnosed with VVC?
Asymptomatic male sexual partners do not need treatment if their female partner has either uncomplicated or recurrent candidiasis.
69
Does nystatin (used in the treatment of VVC) damage latex?
No, but some anti-fungals do
70
What type of organisms are yeasts?
Yeasts are eukaryotic, unicellular microorganisms which have the ability to develop multicellular characteristics by forming pseudohyphae and biofilms
71
Can contraception increase the risk of recurrent VVC?
Oestrogen containing contraceptives increases recurrence risk. There may be a possible risk that yeast may form a biofilm on Cu-IUD causing treatment resistance however there is no consistent evidence.
72
What proportion of VVC cases are caused by C. albicans?
80-89%
73
Aside from C.albicans, what other organisms can be responsible for thrush?
1. C. glabrata,
2. C. tropicalis
3. C. krusei
4. C. parapsilosis
5. Saccharomyces cerevisiae
74
What proportion of women will have a) at least one episode and b) two or more episodes of VVC?
a) 75%
b) 40–45%
75
What genotype may be associated with increased susceptibility to recurrent or acute VVC?
Mannose binding lectin (MBL) deficiency is a genetic condition that affects the immune system. Several studies have shown that MBL codon 54 gene polymorphism (in particular, possessing the MBL variant allele B heterozygous genotype) is associated with recurrent and acute VVC
76
What microscopic features are suggestive of candida?
1. Blastospores
2. Pseudohyphae
3. Neutrophils
77
What microscopic features are suggestive of C. glabrata specifically?
Blastospores and neutrophils ONLY
78
In the context of recurrent VVC, what medium should be used for direct plating?
A solid fungal growth medium (Sabouraud plate)
79
What is the benefit of direct plating in recurrent VVC?
Quantification of candida
80
Why can candida not be quantified from other fungal transport mediums?
If kept in transport medium for
more than 12 hours, quantification is unreliable due to continued growth
81
What is the usual vaginal pH in VVC?
pH 4-4.5
82
What advice should be given in relation to contraception, when using multiple dose fluconazole therapies?
Fluconazole is a moderate inhibitor of cytochrome
P450 (CYP) isoenzyme 2C9 and a moderate inhibitor of CYP3A4
The enzyme inhibiting effect of fluconazole persists 4–5 days after discontinuation of fluconazole treatment due to the long half-life of fluconazole
83
Why should fluconazole not be used in pregnancy?
Possible associations with:
1. Tetralogy of Fallot
2. Cleft lip with cleft palate
3. Increased risk of spontaneous abortion
4. Shorter anogenital distance
84
Is HRT associated with VVC?
Yes
85
What type of organism is TV?
An anaerobic flagellated protozoon
86
What proportion of women are asymptomatic of TV?
10-50%
87
What proportion of women with TV experience the classic frothy yellow discharge?
10-30%
88
What proportion of women with TV have a 'strawberry cervix'?
2%
89
What is the sensitivity/specificity of microscopy for TV?
Specificity is high, sensitivity however is only 40-60%, and so a negative result should be interpreted with caution
90
What stain can be used to identify dead TV organisms?
Acridine orange
91
How quickly does a wet slide for TV need to be interpreted?
Within 10 minutes
92
What is the sensitivity/specificity of NAAT testing for TV in women?
Vaginal/endocervical swabs and urine
samples - sensitivities of 88%–100% and
specificities of 95–100%
93
To what degree may there be metronidazole resistance in TV?
In the USA, it is estimated that 5% of clinical
isolates of TV exhibit some degree of metronidazole resistance, predominantly low level
94
For what reasons should a TV NAAT TOC be performed?
Tests of cure are only recommended if the patient remains symptomatic following treatment, or if symptoms recur
95
What is the optimal timing for a TV NAAT TOC, if required?
4 weeks after the start of treatment
96
What are the virulence factors of TV?
1. Microtubules
2. Microfilaments
3. Bacterial adhesins
4. Cysteine proteinases
97
What type of bacteria is Treponema pallidum pallidum?
Spiral-shaped, Gram-negative, highly mobile bacterium
98
What is the incubation of primary STS?
Incubation is usually 21 days (range 9-90)
99
Over what time period does a primary STS chancre resolve?
3-8 weeks
100
What proportion of people will develop secondary STS if primary STS goes untreated?
25%
101
How long after the primary chancre does secondary STS develop?
4-10 weeks after initial chancre
102
How long will it take for secondary STS to resolve?
3–12 weeks and the disease enters an asymptomatic latent stage
103
How long after the initial infection does late latent (tertiary) disease develop after the initial infection?
20-40 years
104
Within how many weeks of birth does early congenital STS present?
5 weeks (over 2/3rds will be asymptomatic at birth)
105
A quantitative RPR/VDRL of what indicates active disease?
RPR/VDRL titre of 16 usually indicates active disease and the need for treatment
106
When is a false-positive in STS more likely?
1. In autoimmune disease
2. Older age
3. Injecting drug use
107
What regimen should be used in primary, secondary and early latent STS treatment, in those whom are penicillin allergic?
Doxycycline 100mg PO BD 14 days
108
What regimen should be used in late latent/tertiary STS treatment, in those whom are penicillin allergic?
Doxycycline 100mg PO BD for 28 days
109
Which STS patients should receive steroids with their Abx treatment?
Steroids should be given with all anti-treponemal antibiotics for cardiovascular and neuro-syphillis; 40–60mg prednisolone OD for three days starting 24hours before the antibiotics
110
In neurosyphillis, when procaine may be used in therapy, what reaction may occur?
The procaine reaction is an acute reaction from inadvertant intravenous administration of procaine and is characterised by fear of impending death, hallucinations and fits. The reaction normally resolves within 20 minutes.
111
How is early syphillis treated in pregnancy?
Trimesters one and two (up to and including 27 weeks):
Benzathine penicillin G 2.4 MU IM. Single dose.
Trimester three (from week 28 to term):
Benzathine penicillin G 2.4 MU IM, on days 1 and 8
112
How may a Jarisch-Herxheimer reaction present?
An acute febrile illness with headache, myalgia, chills and rigours which resolves within 24 hours
113
What is the usual F/U in STS?
Clinical and serological (RPR or VDRL) F/U is at 3, 6 and 12 months, then if indicated, six monthly until VDRL/RPR negative
114
What degree of increase in VDRL or RPR titre suggests re-infection?
A sustained four-fold or greater increase (also characterised by a recurrence of signs or symptoms, and re-infection excluded)
115
What is the recurrence rate of BV within 7 months?
72%
116
What is the pH of vagina in the context of BV?
Over 4.5, up to 6.0
117
What proportion of women have symptoms with BV?
50%
118
What criteria does BASHH suggest for the identification of BV?
Hay/Ison criteria
119
What is Grade 1 Hay/Ison?
Grade 1 (Normal): Lactobacillus morphotypes predominate.
120
What is Grade 2 Hay/Ison?
Grade 2 (Intermediate): Mixed flora with some Lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present
121
What is Grade 3 Hay/Ison?
Grade 3 (BV): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent Lactobacilli
122
How many of Amsel's criteria need to be present to make a diagnosis of BV?
3/4
123
What are Amsel's criteria for BV?
1. Thin, white, homogeneous discharge
2, Clue cells on microscopy of wet mount
3. pH of vaginal fluid >4.5
4. Release of a fishy odour on adding alkali (10% KOH)
124
What is the most common cause of abnormal discharge in women of childbearing age?
BV
125
What are bacteria are most commonly found in BV?
Gardnerella vaginalis
Prevotella spp.
Mycoplasma hominis
Mobiluncus spp
126
What types of bacteria are responsible for BV?
Flora is dominated by many anaerobic and
facultative anaerobic bacteria
127
What pregnancy outcomes is BV associated with?
1. Late miscarriage
2. Preterm birth,
3. PPROM
4. Postpartum endometritis
128
What type of bacteria is lactobacilli?
Gram +ve, rods
129
What type of bacteria is Gardnerella vaginalis?
Gram-variable-staining facultative anaerobic coccobacilli (short rods)
130
When >35 y/o what type of organism is most likely to be responsible for EO?
Non-sexually transmitted gram-negative enteric organisms causing urinary tract infections
131
What are the non-infective causes of EO?
1. Behcet’s disease
2. Adverse effect of amiodarone treatment
3. Henoch–Schonlein purpura (the commonest vasculitic disease in children)
4. Familial Mediterranean fever
5. Polyarteritis nodosa
132
What is the F/U period in EO?
48-72 hours - if no improvement within 3 days - consider alternative diagnosis
133
In those with penile urethral GC, what proportion of patients exhibit sysmptoms?
90%
134
How quickly do symptoms of penile urethral GC occur?
Usually 2-5 days
135
How long do DNA NAAT tests take to reliably exclude ongoing infection in GC?
14 days
136
How long do RNA NAAT tests take to reliably exclude ongoing infection in GC?
7 days
137
What is the 'look-back' period for GC?
2 weeks if symptomatic penile infection, all other scenarios of GC +ve = 3 months.
138
What is the sensitivity of urethral/meatal microscopy of symptomatic males with GC?
90-95%
139
What is the sensitivity of endocervical microscopy of symptomatic females with GC?
37-50%
140
What is the sensitivity of NAATs in both symptomatic and asymptommatic infection?
>95%
141
What proportion of patients with GC have concurrent CT?
19%
142
What is the aetiology of HSV-1?
The usual cause of oro-labial herpes and now the most common cause of genital herpes in the UK
143
What is the aetiology of HSV-2?
Historically the most common cause of genital herpes in the UK, and the virus type that is more likely to cause recurrent anogenital symptoms
144
What proportion of patients with HSV-2 will be assymptomatic during primary infection?
Often assympto - only one third will show symptoms
145
What type of virus is HSV?
Large double stranded DNA virus
146
How does previous infection with HSV-1 affect acquisition of HSV-2?
Prior infection with HSV-1 modifies the clinical manifestations of first infection by HSV-2, usually making symptoms less severe
147
Following primary infection, where does the virus become latent, periodically reactivating?
Local sensory ganglia
148
What is the typical recurrence rate with HSV after symptomatic primary infection?
Four recurrences per year for HSV-2 and is four times more frequent than the recurrence rate for HSV-1. Recurrence rates decline over time in most individuals, although this pattern is variable.
149
What proportion of patients develop lymphadenitis with HSV?
30%
150
What is the reduction in HSV episode duration with episodic oral aciclovir?
Reduction in duration is a median of 1–2 days.
151
What is the aetiology of neonatal HSV?
HSV-1 (50%) or HSV-2 (50%)
152
What is the risk of neonatal HSV transmission in a primary episode?
41%
153
What is the risk of neonatal HSV transmission in a recurrent episode?
0-3%
154
In what proportion of neonatal HSV is a postnatal source identified?
25%
155
What proportion of neonatal is disseminated?
70%
156
What is the mortality and neurological morbidity in disseminated neonatal HSV?
Mortality ~30%
Neurological morbidity - 17%
157
What is the management if first episode of HSV acquired before 28/40 gestation?
Suppressive aciclovir from 36/40
C-section if within 6 weeks of delivery date
158
What is the management if first episode of HSV acquired AFTER 28/40 gestation?
Aciclovir between acquisition and delivery
C-section (unless type-specific HSB antibody testing shows this is not a ture primary episode)
159
What are the risk factors for reactivation of anogenital HSV?
1. Local trauma
2. High conc UV light
3. Immunosuppression
4. Psychological trauma
160
In whom is C.galbrata more common?
Diabetics
161
What are the characteristics of M.gen?
- Single stranded circular DNA
- Self-replicating
- Genome of only 580 kilobases
- Does not contain a cell wall or membrane bound organelles
162
What is the most common site for TV in all genders?
Urethra
163
What type of contraception should be avoided with nucleotide reverse transcriptase inhibitor (NRTI) tenofovir disoproxil fumarate (TDF), and why?
DMPA infection, owing to reduction in BMD
164
What are some examples of NRTIs?
Tenofovir disoproxil fumarate
Tenofovir alafenamidee
Emtricitabine
Abacavir
Zidovudine
165
What are some examples of NNRTIs?
Efavirenz
Nevirapine
Etravirine
166
What are some examples of protease inhibitors?
Atazanavir/ritonavir
Lopinavir/ritonavir
Darunavir/ritonavir
167
What are some examples of integrase strand transfer inhibitors?
Raltegravir
Dolutegravir
168
What are some examples of pharmacokinetic enhancers?
Ritonavir
169
Which enzyme inducing NNRTI is expected to reduce the effectiveness of contraception?
Efavirenz (EFV)
170
Which NNRTIs are enzyme inducers, but not expected to have an effect on contraception?
Etravirine (ETR)
Nevirapine (NVP)
171
Which NNRTIs are NOT enzyme inducers?
Doravirine (DOR)
Rilpivirine (RPV)
172
How may protease inhibitors affect contraception?
Cobicistat boosted PIs may INCREASE ethinylestradiol exposure in COCP use, and so theoretically increases the risk of VTE
172
How may cobicistat-boosted INSTIs affect contraception
cobicistat-boosted INSTIs may DECREASE ethinyestradiol exposure, and so shouldn't be used in low-dose COCPs
173
Which ARTs may reduce the effectiveness of oral EC?
The enzyme inducing NNRTIs - Efavirenz (EFV), Nevirapine (NVP) and Etravirine (ETR)
174
What is the risk of HIV with receptive anal intercourse (with someone with known HIV, not on ART)?
1 in 90
175
What is the risk of HIV with insertive anal intercourse (with someone with known HIV, not on ART)?
1 in 666
176
What is the risk of HIV with receptive vaginal intercourse (with someone with known HIV, not on ART)?
1 in 1000
177
What is the risk of HIV with insertive vaginal intercourse (with someone with known HIV, not on ART)?
1 in 1219
178
What is the risk of HIV in oral SI/human bite (with someone with known HIV, not on ART)?
<1 in 10,000
179
What is the risk of HIV in needlestick injury (with someone with known HIV, not on ART)?
1 in 333
180
Is the risk of HIV acquisition in the late pregnancy and post-partum period higher?
Yes
181
What is the recommended regime for PEPSE?
Tenofovir disoproxil 245mg/emtricitabine 200mg - once daily
PLUS
Raltegravir 1200mg - once daily
182
What viral load is considered undetectable?
<200 copies/ml
183
What two criteria are required for someone to be considered undetectable:
1. Undetectable plasma HIV viral load (tested within previous 6 months)
2. Good reported adherence to ARV therapy for the past 6 months
184
In once daily dosing, how long does it take before HIV can be relied upon?
7 days
185
When event-base dosing is used, how quickly is protection offered after taking two pills?
2 hours
186
What type of virus is HIV?
Lentivirus
187
What are the characteristics of lentivirus?
1. RNA viruses
2. Single-stranded
3. Positive sense
4. Enveloped
5. Contain ‘gag’, ‘pol’ and ‘env’ genes
6. Cause long-duration illnesses with long incubation times
188
What is used in first generation HIV tests?
Western blot
189
What is the median time to detection of HIV with fourth generation HIV tests?
17.8 days - 99% detection by 44.3 days
190
What is used in fourth generation HIV tests?
Combination test: detects HIV IgM and IgG antibodies as for third generation tests + p24 antigen using monoclonal antibodies
191
What gene are the HIV glycoproteins encoded on?
The viral gene - 'env'
192
A CD4 count of <200 constitutes what UKMEC rating for IUS insertion?
UKMEC 3
193
If a CD4 count falls <200 with the IUS still, should the IUS remain in?
Yes - benefit outweighs risk
194
How are fungi differentiated from other kingdoms?
By their cell wall content which contains a matrix of polysacchardises (mannan or glucan) and proteins bound to chitin (unlike bacteria, where cell wals amy be peptidoglycan or cellulose)
195
What are the features of gram negative bacteria?
1. Contain a thin peptidoglycan later sandwiched between an outer membrane and an inner cytoplasmic membrane
2. Lipopolysaccharides (LPS) found in the outer membrane provide protection, structural integrity and act as an endotoxin (LPS is only found in gram negative cell walls and contains a lipid A portion)
3. Do not retain crystal violet on Gram staining (so appears pink)
196
What are the characteristics of eukaryotic organisms?
- Large
- Unicellular or multicellular
- Nucleus
- Membrane-bound organelles
- Division by mitosis
- E.g. plants and animals
197
What are the characteristics of prokaryotic organisms?
- Small
- Unicellular ONLT
- NO Nucleus
- NO Membrane-bound organelles
- Division by binary fission
- E.g. bacteria
198
What is the sensitivity and specific of NAATs in CT?
Both are very high (although specifity>sensitivity)
199
How do NAAT tests work?
Identification of genetic material (DNA or RNA), usually by some form of nucleic acid hybridization (labelled complementary DNA/RNA), after that genetic material has been amplified to make identification easier. Amplification may taken place in different ways, but could include by PCR or ligase chain reaction (LGR)
200
How many times per day should aciclovir be taken when using for suppressive therapy in pregnancy?
TDS
201
Which part of the cell wall picks up a gram stain on microscopy?
Peptidoglycan
202
What proportion of women with STS in pregnancy experience a stillbirth/baby dies as a newborn as a result of the infection?
40%
203
Should an infant with congenital STS survive, was possible problems may it have?
1. Deformed bones
2. Severe anemia
3. Hepatosplenomegaly
4. Jaundice
5. Brain and nerve problems, like blindness or deafness
6. Meningitis
7. Skin rashes
204
What type of bacteria is Actinomyces israelii?
Gram-positive anaerobic bacteria
