“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)