“tales from the west”: interesting cases from a county
TRANSCRIPT
“Tales from the West”: Interesting Cases from a County Hospital
Susan Butler-Wu, Ph.D., D(ABMM), SM(ASCP)
Associate Professor, Keck School of Medicine of USC
Director, Clinical Microbiology Laboratory, LAC+USC
Medical Center
Case 1: Things are not always what
they seem…
• 45 yo incarcerated male in Los Angeles, CA presented to jail ED with difficulty walking & confusion – ESRD, hypertension, CHF
• Several months prior had a VP shunt placed for unclear reasons
• Patient became more agitated, had started vomiting and was transferred to LAC+USC for care
VP-CSF Values Ref. Range
WBC 79 0-5 cells/µl
• PMN • 67%
• Lymphocytes • 20%
• Monocytes • 13%
Glucose 31 mg/dL 50-80 mg/dL
Protein 29 mg/dL 20-50 mg/dL
Gram Stain of CSF
Name that bug!
Growth on SAB at 3 days
Answer
• Coccidioides spp.
Hagman HM et al. Clin Infect Dis. 2000. 30:349-355 Schuetz AN et al. Diagn Cytopathol. 2012. 40(2):163-7
Fine needle aspirate
• 16 year old Male with arthrogryposis and short stature presented with 3
weeks history of worsening back pain
– dull and mainly localized to the upper back, increased to 9/10 with touch
– no fall or trauma to back; no other joint pain
• Denied any chest pain, however, did say that he had been a little out of
breath over the past few weeks
• Also endorsed vague history of occasional night sweats and a fever of
101°F over the past few weeks
• US born, no travel history. Frequent family visits by relatives from Mexico
frequently but no known sick contacts
• On exam, the pt was febrile (38.2°C - Tmax 39.2°C) and tachycardic (HR:
126)
• 3-4/6 systolic murmur was appreciated on exam that was best heard
over LSB
• Scoliotic spine, approximately 7 cm x 7cm very tender and fluctuant mass
in the right lower thoracic region with faint overlying erythema
• WBC 22.2 (78% N), CRP 255 ESR 108
Dr. Elham Rahmati
Case 2: Lumpy-Bumpy
Chest CT Key Findings: RLL consolidation. 4.5x
9.3x15.5 cm mass extending through tissue
boundaries involving pleura, communicating
with a large fluid collection within the right
paraspinal musculature.
• Fine Needle Aspirate
• Growth on BAP, CHOC
• NG on MAC
• Oxidase-neg
• Catalase-pos
• Indole-neg
• Anaerobic culture grew
Fusobacterium spp.
H&E
Name that bug!
Answer
• Aggregatibacter actinomycecomitans
(formerly Actinobacillus actinomycecomitans)
Based on the pathology
findings, what other
organism do you suspect is
present?
Answer
• Actinomyces spp
GMS
Gram-positive rods observed
with Brown & Brenn stain
• 26 yo male with no significant PMH
• Brought into OSH ED by his sister for AMS & HA after she had difficulty arousing him – headache began one week PTA
– pt was seen at OSH discharged, with Norco
• Throbbing HA, as well as all over body pain – no photophobia or neck stiffness
– per family had polyuria/polydipsia in last few days
• Became agitated and combative in ED
• Pt stated that he was born in US
• Works as cook in a Guatemalan restaurant
• Denies travel outside of CA
Case 3: “My head is killing me”
Case continued
• Underwent lumbar puncture – opening
pressure of 55
CSF
RBC 10
WBC 99
%PMN 72%
%Lymph 20%
% Mono 8%
Glucose 39
Protein 120
• Became febrile over the course
of his hospitalization (Tmax
38.3°C)
• Developed hydrocephalus
• EVD placed
• Progressive de-compensation
Dengue IgG 5.73
Dengue IgM 1.25
Serum WNV IgG 4.48
Serum WNV IgM neg
The following colonies were observed after 14
days of incubation of the CSF culture
Name that bug!
Answer
• Mycobacterium tuberculosis complex
• MTBC is capable of growth on routine
bacterial culture media
What aspect of how this
culture was performed
led to isolation of this
organism?
Answer
• Extended culture incubation for CSF from shunt specimens over concern for Propionibacterium spp (Cutibacterium)
• No published data examining utility of extended culture incubation for shunt specimens
• Unpublished data: 69/70 CSF shunt samples positive for Propionibacterium spp positive within 7 days (Dr. Lori Bourassa, University of Washington)
• 52 yo Laotian male was diagnosed ALL
– underwent two rounds of hyperCVAD (chemotherapy)
– generalized pruritus (itching) and urticaria after first
round – stopped TMP/SMX
– pruritis persisted
• Presented to OSH with back pain & nausea 6 days
after having begun chemo
– sx improved after IVF, opioids & he was discharged
• 2 days later, presented to UWMC with abdominal
pain, nausea, emesis & chills
– thought to be due to regimen-related toxicity/colitis
Case 4: Creepy Crawly
• CT of abdomen & pelvis
• colitis involving cecum and ascending colon
• ground-glass opacities and nodules in lung bases
• Pt became hypoxic, CT chest:
– diffuse nodular ground-glass opacities
• Intubated and underwent bronchoscopy
BAL Gram Stain
BAL culture was negative for bacteria,
fungi, AFB What is the diagnosis?
http://parasitewonders.blogspot.com/2010_10_01
_archive.html
Answer
• Strongyloides stercoralis hyperinfection
syndrome
Image: CDC DPDx
True or False: Patients
with hyperinfection
syndrome usually have
an elevated eosinophil
count
False: Absence of eosinophilia does not rule out
Strongyloidiasis
• Diagnosis requires a high degree of clinical
suspicion • 50% of chronically infected patients are asymptomatic, 50% with only minimal
or intermittent GI symptoms
• 9% of US-trained MD’s recognize case presentation of a person needing screening for Strongyloides vs. 56% of foreign-trained physicians
Boulware DR. Am J Med. 2007.120:545
Roxby AC et al.CID. 2009. 49(9):1411-23
• 64 yo homeless man presents to LAC+USC ED c/o
2 weeks of productive cough, exertional SOB,
decreased appetite and fatigue for the last 5 days
– subjective fevers and night sweats
– yellow sputum
– no nausea, vomiting or diarrhea
• Patient was born in Mexico, moved to the U.S. 28
years ago
• No travel, no substance abuse (including IDU)
• Patient also complains of intermittent left sided
chest pain “all around my heart” – no radiation of pain
Case 5: Itchy itchy, scratch scratch
Case continued…
• Recent history of staying in a homeless shelter and body lice were discovered on the patient
• CXR showed questionable cavitation – MTB PCR neg x2, AFB smear-neg x3
• Afebrile & normal WBC noted
• Admitted for diuresis, TB r/o and CAP – started on ceftriaxone & azithromycin
• TEE to evaluate cardiac function revealed EF 35% and a 1.6x1.4 aortic vegetation on non-coronary cusp
• Blood cultures were negative x3 sets
• The patient had positive serologies for this organism (IgG 1:1024)
• Patient underwent valve replacement
• H&E staining showed acute and chronic inflammatory changes
• Warthin Starry staining of the excised valve was performed…
Name that bug!
Answer
• Bartonella spp.
• B. quintana IgM-neg, IgG 1:512
• B. henselae IgM-neg, IgG 1:1024
Pediculus humanus corporis
Foucault et al. Emerg. Inf. Dis. 2006.
Names two other
important causes of
culture-negative
endocarditis that cannot
be grown in vitro but
can be visualized by the
Warthin Starry stain?
Answer
• Coxiella burnettii & Tropheryma whipplei
• T. whipplei was the most common cause of
culture-negative endocarditis in one study
from Europe (6.3% of endocarditis cases)
• Outbreaks of C. burnettii e.g. Netherlands
Geissdörfer et al. JCM. 2012 50(2):216-22
• 52 yo M presented to LAC+USC ED
• 1 week of AMS after physical altercation
• Pt was tachycardic, hypotensive and had leukocytosis (WBC 14.0)
• Pt has a hx of polysubstance abuse
• Blood cultures positive after 2 days of incubation
2/2 blood culture sets positive –
growth in anaerobic bottle only (i.e.
2/4 bottles positive)
Case 6: Death-spiral
More information
• Organism did not grow at 35°C in 5% CO2
• Growth observed after incubation in microaerobic atmosphere
• Growth observed after anaerobic incubation (more “spready”)
Oxidase-negative, Catalase-negative
Name that bug!
Answer
• Anerobiospirillium succiniciproducens
• Identified by both MALDI-TOF Mass
Spectrometry (Bruker Biotyper) & 16S rDNA
sequencing
What two antibiotics is this organism frequently
resistant to?
Answer
• Metronidazole and clindamycin
• Generally susceptible to combined beta-
lactam and beta-lactamase inhibitors, 2nd, 3rd
and 4th generation
cephalosporins,
carbapenems, &
fluoroquinolones
• 52 yo male presents with a 10-day history of fevers and headache after having returned from a 3-week trip to Chiang Mai, Thailand
– pt is US born of Pakistani origin; had not been to Pakistan in over 15 years
• He received the recommended vaccinations prior to travel and took appropriate malaria prophylaxis
• On exam, the patient was noted to be febrile to 38.9°C
• The patient also noted that he had been experiencing diffuse myalgia for the last two days
• On exam, a 1cm x 1.5cm area of discoloration was noted on the patients leg
• WBC 3.2 (leukopenic)
• ALT 180, AST 205
Case 7: Thai thigh
• The patient had negative malaria smears x3
• The patient had negative Rickettsial serologies
performed at a local reference lab (both
spotted fever and typhus group)
• The diagnosis of this rickettsial disease was
made by serology testing performed at the
CDC
Name the etiologic agent of
this patient’s infection and its vector
Answer
• Infection: Orientia tsutsugamushi
• Vector: Chiggers (Leptotrombidium spp)
Looking at 5 distinct
regions, prevalence
varied from 4.1-23.4%
Suttinont et al. Ann Trop Med Parasitol. 2006 Jun;100(4):363-70
Scrub typhus: “The tsutsugamushi
triangle”
Image: WHO
• 55 yo female visiting from Cameroon, Africa
• Two days after arrival in U.S. began to experience nausea and NBNB emesis 8-10 times a day and diarrhea more than 8 times a day
• A further two days later, was found slumped over by her sister and an ambulance took her to an OSH – mildly tachycardic and hypertensive
– AST >4440, ALT>5000, INR of 8.42, lactate 8.4, troponin 16.1
• Transferred to LAC+USC for transplant evaluation – suspected acute liver injury due to medication taken immediately prior to leaving for the U.S.
• 9 days after coming to the U.S. pt became progressively more altered and intubated for airway protection
Case 8: A long way from home
• Blood sample drawn at 00:46am 6 days after
arrival in the U.S. was positive for the
following
Sheath?
220-232µM
Name that bug!
Answer
• Loa loa
At what time are Loa
loa microfilaria most
likely to be detected in
the blood?
Answer
• 10am-2pm i.e. diurnal periodicity
• Need to account for time at the patient’s original destination – microfilaria can be jet-
lagged too
Diethylcarbamazine (DEC) is
the drug of choice when the
concentration of microfilaria
is <8000 MF/mL. However,
co-infection with which other
microfilaria species must be
ruled-out prior to initiation of
DEC therapy?
Answer
• Onchocerca spp
• Risk of fatal encephalopathy if co-infected
• No role for doxycycline as Loa loa do not
contain Wolbachia
• 17 y/o Filipino boy with a history of fevers & chronic cough with sputum for 6 months PTA – no weight loss or night sweats
• Diagnosed with acute bronchitis at 4 separate ED visits at OSH’s – tx with azithromycin, promethazine,
dextromethorphan
• 2 months PTA his right cheek became swollen and he developed scaly skin lesions on back, chest, extremities as well as cutaneous horns on face – cheek swelling grew and extended to lid and forehead
• PCP referred pt to Optho who instructed him to come to the ED
Dr. David Yau
Case 9: What’s horny is thorny
Case continued… • Patient was born in USA, lives in Glendale
– no out of state travel
– visited Palm Springs 9 months PTA, and 3 months PTA stayed in cabin “in the snow”
• On Exam: – Shotty cervical lymphadenopathy; prominent
supraclavicular lymph node, right axillary node palpable, no palpable inguinal nodes
– HEENT: Right eye swollen, periorbital edema/STS, + eye discharge, +fluctuant swelling
– exophytic hyperkeratotic yellowish horn-like nodules on left lateral eyebrow and left cheek:
– L lateral upper arm, mid back, central upper back, R chest with vegetative crusted plaques with erythematous base
– WBC 11.1
• “Complex multilocular cystic mass with enhancement in the right frontal scalp extending inferiorly to just beneath the right zygomatic arch with cortical irregularity and a permeative appearance of the underlying bones, as above, concerning for neoplastic process.
• Multiple enlarged cervical lymph nodes, some with central necrosis, concerning for a neoplastic process”
Wet mount of drainage (40X)
Name that bug!
Structures >5µM
Answer
• Coccidioides spp.
H&E Back lesion punch
Qs. What other ethnic
group has a greater
risk for developing
disseminated
Coccidioides infection?
Answer
• African ancestry
– 10 times greater risk
• Filipino ancestry
– 175 times greater risk
• 51 yo man taken to LAC+USC after being found down – currently incarcerated
• Patient has a history of schizophrenia and seizure disorder
• Had a similar presentation one month prior; at the time was attributed to sepsis from aspiration pneumonia – improved on fluids and antibiotics
• On exam, he was bradycardic to the 30’s, hypothermic and altered
• CT head was normal – no intracranial abnormalities, hemorrhage, large territory infarct, or mass effect
Case 10: Panel it out
Case continued…
• VZV detected by Biofire ME panel
CSF
WBC 47
% Lymphocytes 92%
Glucose 22
Protein 173
True or False: There are
patients with VZV
meningitis/encephalitis
that do not have skin
lesions
Answer • True
• VZV reactivation can produce chronic radicular
pain without rash (known as zoster sine
herpete)
• Neurological disorders associated with VZV
can also occur without a rash
• 49 y/o F presents to ED for with severe throat pain,
dysphagia, hoarseness, myalgia, fevers, and chills for 3 days
– no recent sick contacts; has 3 school aged children
– Unknown vaccination status
• PMH of connective tissue disease, diabetes mellitus
• On physical exam, membranous plaques on posterior
oropharynx, tonsillar erythema and enlargement as well as
tender cervical lymphadenopathy were noted
– patient spoke with a muffled voice
• T 38°C, tachycardic (127), BP 127/82, O2 Sat 99% on room
air
– Cardiac: Normal S1/S2, RRR
• WBC 12.9 K
Case 11: The horse is out of the barn
Name that bug!
Image: Dr. Noah Wald-Dickler
Image: Dr. Noah Wald-Dickler
Answer
• Corynebacterium diphtheriae
Prior to initiating anti-toxin
therapy, patients must be
tested for hyper-sensitivity to
what substance?
Answer
• Horse serum
• 10% risk of hypersensitivity and/or
serum sickness
• Dose of antitoxin depends upon the site
and severity of infection
What test is used to
demonstrate toxin production
in vitro?
Answer
• Elek test An immuno-precipitation test
• filter paper saturated with
diphtheria anti-toxin is
submerged in agar
• test isolate is streaked
perpendicular to filter paper
• precipitin at 45° angles if isolate
produces toxin
• Strains of C. ulcerans & C.
pseudotuberculosis can also
potentially produce diphtheria
toxin
• 3 yo previously healthy female presenting with fever (40.2°C)
– fevers started 3 months ago, lasted for several weeks, then returned 10 days ago
– now occurring daily, fevers last several hours then resolve with acetaminophen
• Had cervical lymphadenopathy, hepatosplenomegaly on exam
– hepatosplenomegaly confirmed by ultrasound
• Normal WBCs, but labs showed microcytic anemia and increased ALT (134), AST (134), Alk Phos (381) and CRP (22)
• Mom reports that the entire family had eaten goats cheese from Mexico 6 months ago
• 2/2 blood culture sets drawn are positive for growth at 3 days (aerobic bottles)
Case 12: You are what you eat…
Name that bug!
Answer
• Brucella species
B. abortus strain RB51
was developed to
immunize which
domestic animal
against brucellosis?
Answer
B. abortus strain RB51 is
resistant to which
antibiotic? Table: CDC
• Cattle
• Accidental exposure has
led to infection in
humans
• Raw milk consumption
• Human infections with RB51 are not detectable with
standard serologic assays!
• B. abortus S19 for cattle and B. melitensis Rev-1 for
sheep and goats – accidental exposure leading to
infections also reported
Answer
• Rifampin-R
• Post-exposure prophylaxis for suspected B.
abortus RB51= 21-day course of doxycycline
and trimethoprim/sulfamethoxazole
• 40 yo M from Mexico
• Reports experiencing steadily worsening exercise
tolerance/increasing SOB, increased fatigue,
intermittent chills and myalgias
• Hx of EtOH cirrhosis and recurrent
hospitalizations for anemia (Hgb 2.4-5.5)
• Feels his abdomen has been growing in
circumference and reports recent decreased PO
intake
Case 13: Unlucky for some…
• Worked on a farm in Mexico
– drank occasionally from
rivers while living in
Mexico
• Moved to L.A. one year PTA
– works as a street vendor
• Alk Phos 164 U/L
• AST 20 U/L
• ALT 16 U/L
• WBC 5.2, 23% eos
• Hgb 3.6 , MCV 61.3
MRI: Marked intra- and extra-
hepatic biliary dilatation with
abnormal signal in the right
and common bile ducts
concerning for
cholangiocarcinoma
• Pt underwent ERCP
• No evidence of cholangiocarcinoma
• ERCP showed debris in the gallbladder
and extra-hepatic bile duct, which was
"swept" with a balloon…
Video: Dr. Erin Dizon
Name that bug!
Image: Dr. Ryan McConnell
Size: 130µM x 75µM
Answer
• Fasciola hepatica
What agent should not
be used to treat this
infection?
Answer
• Praziquantel
– active against most trematodes, but not Fasciola
• Triclabendazole is the drug of choice
– in the United States, this can only be obtained
through the CDC Drug Service
A Special thanks to the amazing Clinical Laboratory Scientists, residents and fellows who took care of all
the patients in the cases presented today!
www.cheezburger.com
• 3yo M with hemophilia A presents to establish
care
– family recently emigrated from Afghanistan
– treated in Afghanistan with monthly “plasma injections”, which were donated from Italy
• Mother denies history of blood transfusions
• The child bruises easily & experiences
prolonged bleeding with trauma
• Review of systems was otherwise negative
• HepBsAg: nonreactive
• HCV Ab: nonreactive
• RPR: nonreactive
HIV Antibody/Antigen Results:
Repeatedly Reactive
HIV1 Ab: negative
HIV2 Ab: indeterminate
HIV1 RNA: not detected
What testing should be
performed next?
Answer
• HIV-2 RNA (quantitative)
• HIV-2 viral loads are frequently
undetectable
• Titer is 2–3 log 10 lower than in HIV-1-
matched controls
• 80% of people living with HIV-2 behave
like HIV-1 long-term non-progressors HIV-2 is intrinsically
resistant to which
class of ARs?
Answer
• Non-nucleoside reverse transcriptase
inhibitors
Image: aidsinfo.nih.gov
• 67 yo F presents to ED with breakthrough seizures
– PMH of epilepsy, chronic R sided headache, vertigo,
DM, hypertension, cirrhosis
• While in the ED, she had a witnessed tonic-clonic
seizure with drop in Sp02; was intubated for airway
protection
• Chest X-ray showed bilateral opacities & interstitial
opacities
• Over the course of her hospitalization, she developed
worsening shortness of breath
• Pt was started on ceftriaxone/flagyl for presumed
aspiration pneumonia & was subsequently switched to
vanco/cefepime for VAP
• No improvement in her respiratory status & pt
Name that bug!
H&E GMS
Mucicarmine
Answer
• Cryptococcus spp
Vs. “C. neoformans
complex” & “ C.
gattii complex”
Kwon-Chung KJ et al. mSphere. 2017. 2(1). pii:
e00357-16. Images: relatably.com & Pin
Patient’s CSF Cryptococcal antigen: Initially Reported as negative
What is this
phenomenon called?
Answer
• High dose Hook effect (prozone)
True or False: Positive
CSF CrAg results
correlate strongly with
positivity for the
Cryptococcus target on
the Biofire ME panel
Answer
• False
Liesman RM et al. 2017. J Clin. Microbiol. 56(4): pi
17
• 56 yo male with mantle cell lymphoma, underwent 6 cycles of chemotherapy and an autologous BM transplant
• Post-transplant course complicated by neutropenic fever and mucositis
• Received 2 bags of RBC’s, followed 3 days later by 2 bags of pooled platelets after which hematocrit was 27 and his platelet count was 10,000
• Two months later, presented with fever and hemolysis; also reported a 14 lb weight-loss and severe fatigue
• He was pancytopenic upon admission
• Patient lives in a wooded area in Western WA, but denied working outside since his lymphoma diagnosis
• No recent travel history and denied tick bites
Name that bug!
Answer
• Babesia spp.
What Babesia species is
native to the US West
Coast?
Babesiosis in the US
• Identified by CDC as Babesia microti
Infections in CT, MA, MN, NJ, NY,
RI and WI account for 95% of
Babesiosis cases – B. microti
Three reported cases of B.
divergens-like spp. in the US
Vannier EG et al Inf Dis Clin N Am. 2015. 29(2):357-70
Image: CDC, 2013 babesiosis data
• Answer = B. duncani and B. duncani-type
vs.
• Majority of infections associated with tick bites, but infections can be acquired via blood transfusions or transplacentally
• Transfusion-associated infections can occur year round – mortality rates up to 18%
• Asymptomatic infection is common – 53% of Ab-positive donors are also PCR-positive
• Donated blood or blood donors are not currently routinely tested for Babesia – BPAC & FDA met in 2015 to discuss this – http://www.aabb.org/advocacy/government/bpac/Pa
ges/bpacmeeting150513.aspx
Leiby DA et al, Transfusion. 2005. 45: 1804-1810
• 50 yo M with history of HIV – CD4 363, undetectable HIV-1 RNA two months ago
– on ART
• Presents to the LAC+USC ED with 3 days of acute onset of fevers, chills, cough, abdominal pain, nausea, vomiting – no diarrhea or hemoptysis
– on exam, his abdomen was soft, non-tender & non-distended
• T38.1°C
• CXR showed right lower lobe consolidation
• WBC 17.8, 92% N, 4.7% L, 0% E
• Renal impairment (Cr 5.2) & hyponatremia (Na 129, normal 134)
• US born, no travel outside of California
Diagnosis of the cause
of this patient’s infection was made with
which urine antigen
test?
Answer
• Legionella pneumophila
• Some studies suggest that hyponatremia occurs
more commonly in patients with Legionaire’s
disease than with other causes of pneumonia
• Hyponatremia is also noted to occur in patients
with HIV, bacterial meningitis, malaria,
leptospirosis, leishmaniasis and others…
Liamis et al. J Inf. 2011. 63(5): 327-335
Which Legionella
pneumophila serogroup
is detected by the
Legionella urine antigen
test?
Answer
• Legionella pneumoniae serogroup 1
Sivagnanam S et al. Transpl Infect Dis. 2017. (in press)
Anvi T et al. JCM. 2016. 54(2): 401-411
Which Legionella species is
modified-acid fast in primary
specimens?
Answer
• Legionella micdadei
Image: Louis P et al. JCM. 2007. 45(9):3135-3137
• 12 yo girl presents to LAC+USC ED with hip pain that began 3 weeks ago
– describes pain as 8/10
– waking her up at night
• Sharp pain, no numbness or tingling – radiates from hip to knee
• Pain worse when she stands – causes her left leg to shake and affecting her gait
• Pain with palpation, flexion, extension, external and internal rotation
• Reported subjective fevers though was afebrile on examination
• All vitals, WBC & CRP were normal
• The pt is up-to-date with her vaccines
• No travel outside of California
• No pets, no contact with farm animals
• Ate unpasteurized cheese from Mexico 4 months prior to admission
• MRI showed 1.6cm Brodie abscess at the base of the greater trochanter of the left femur with extensive adjoining bone edema and inflammatory changes
– Brodie abscess = intraosseous abscess associated with sub-acute pyogenic osteomyelitis
• Pt underwent CT-guided biopsy
– Gram showed 4+PMNs, but no organisms seen
• 32 yo female presents with complaint of lower back pain for the last 6 months
• Now reports the pain to be constant, 10/10, and no radiating
• Also reports fever/chills, dry-to-productive cough and weight loss over the last 3 months
• Pt was born in Mexico and moved to the US 10 years ago
• Has also lived in Arizona & Kansas; had been previously incarcerated in Mexico
• No drug use, in monogamous relationship with her boyfriend for the last 2 years
• The patient had 3 smears that were AFB
smear negative
• Xpert MTB-Rif assay: positive for M.
tuberculosis
• Rifampin resistance detected
• Culture was subsequently positive but
susceptible to Rifampin in vitro
What is the explanation for
the observed discrepant
results?
Answer
• Silent mutation observed in the rpoB gene
(S14 TTT)
• Haiti: 93% of RIF-R by Xpert were rifampin-R
by susceptibility testing, but FP rate of 54%
among samples with “very low” Mtb (Ct>28)1
1Ocheretina O et al. DMID. 2016. 85(1):53-5
Oxidase-neg
TSI: K/A, H2S+, Gas
ODC+
LDC+
• MALDI only ID’d to genus level
Name that bug!
Answer
• Salmonella spp.
• Identified by PHL as Salmonella group D
serotype Panama
• 45 yo male fainted and struck his head on the ground at work
• Reported a one-month long hx of body aches and mild cough
• HIV positive, but had stopped taking triple therapy 18 months prior to presentation – viral load = 136,000 copies/mL, CD4=9 cells/mm3
• Traveled to Thailand one year ago, but no travel since then
• CXR showed LLL consolidation consistent with pneumonia
• No clinical improvement on broad-spectrum abx, CT without contrast showed a 2.5 cm mass – underwent bronchoscopy and BAL grew the following…
Case 7: Tales from Thailand, part I
30°C
37°C
What is the diagnosis?
Answer
• Penicilliosis
What is the new name for the
etiologic agent of penicilliosis?
How fungal taxonomic changes
make me feel…
• Talaromyces
marneffeii
• Latent infection?
• Immunocompromised develop penicilliosis – variety of clinical manifestations
• **skin papules seen in up to 70% of pts
Wong SYN. Path. Res. Intl. 2011.
• 52 yo M brought in by ambulance after he
was found unconscious by a
family member
• Covered in his own feces
• Pt is a heavy drinker – drinks 1 pint of
vodka a day
• Lactate 4.3, WBC 4.9K
• UA was normal, salicylate/tylenol negative
• Given Ativan for alcohol withdrawal
• One out of two blood culture sets were
positive (anaerobic bottle) Image: www.zazzle.co
Identified as C. perfringens
• Growth on BAP = pos
• Terminal spores when
grown on Brucella
agar
Name that bug?
Answer
• Clostridum tertium
Name one other
aerotolerant
Clostridium species?
Answer
• C. histolyticum
• C. carnis
• (Occasional strains of C. perfringens)