Transcript What I Do - University of Michigan

WHAT I DO
Mike Bachman MD PhD
Assistant Professor
Director, Molecular Microbiology
DUTIES
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Clinical
Director of Molecular Microbiology
 M Labs Service Line Director
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Molecular Microbiology
Malaria Diagnosis
Research
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Principal Investigator
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Innate Immunity to Bacterial Infections
Member, Distributed Health Technologies Cluster
MOLECULAR MICROBIOLOGY LAB
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Section of Clinical Microbiology Laboratory
Testing Performed Seven Days a Week
 Dedicated Team of Technologists
 Coverage of Day Shift
 Afternoon coverage soon
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MOLECULAR MICROBIOLOGY TEST MENU
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Diagnostic Testing
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Herpes Simplex Virus (CSF)
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Detection and Typing
Chlamydia trachomatis/ Neisseria gonnorhoeae
Bordetella pertussis/parapertussis
Clostridium difficile Toxin B
Pneumocystis jiroveci
Respiratory Viruses
Influenza A
 Influenza B
 Respiratory Syncitial Virus (RSV)
 Parainfluenza 1,2,3
 Human Metapneumovirus
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MOLECULAR MICROBIOLOGY TEST MENU
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Viral Load Monitoring
HIV
 Hepatitis B
 Hepatitis C
 CMV
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Viral Genotyping
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Hepatitis C
Adjunct Testing
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High-Risk Human Papillomavirus
TEST DEVELOPMENT
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Herpes Lesion Diagnosis
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High throughput testing to replace culture
Platform for Quantitative Testing
Abbott m2000 (HIV, HBV, HCV)
 EBV
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Platform for Qualitative Testing
HSV, Bordetella pertussis/parapertussis, C. difficile
 Basis for expanding testing
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Human Papillomavirus
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4 FDA-approved assays
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Potential for HPV 16/18 Genotyping
DUTIES

Clinical
Director of Molecular Microbiology
 M Labs Service Line Director




Molecular Microbiology
Malaria Diagnosis
Research

Principal Investigator


Innate Immunity to Bacterial Infections
Member, Distributed Health Technologies Cluster
Asymptomatic
intestinal colonization
- 75% of patients
KLEBSIELLA
PNEUMONIAE
Nasopharynx
Colonization
19% of patients
Pneumonia
#3 hospitalacquired cause
Bacteremia
Genetically
tractable
Iron-chelating
Siderophores are
major virulence
factors
Urinary tract infection
RICHARDS, M.J. ET AL (1999) PEDIATRICS. 103:E39; ZAOUTIS, T.E. ET
AL (2005) PEDIATRICS. 115: 942; LAWLOR, M.S. ET. AL, (2007) INFECT
IMMUN. 75:1463; NASSIF, X. AND SANSONETTI, P.J. (1986) INFECT
IMMUN. 54:603
INNATE IMMUNE RESPONSE TO MICROBIAL
IRON METABOLISM
Iron is required by both bacterial pathogens and
human hosts
 Gram-negative pathogens acquire iron by secreting
iron chelators called siderophores
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Enterobactin
Lipocalin 2 is an innate immune protein that binds
Enterobactin to inhibit bacterial growth
Lipocalin 2
Enterobactin
K. PNEUMONIAE MAY PRODUCE
SIDEROPHORES TO EVADE LIPOCALIN 2
Glycosylated
Enterobactin
Glucose on catechol
rings prevents Lcn2
binding
Yersiniabactin
Fischbach, M.A.
et. al. 2006.
PNAS USA,
103:16502
Does K. pneumoniae require these siderophores to cause disease?
YERSINIABACTIN IS PREVALENT AMONG
K. PNEUMONIAE RESPIRATORY ISOLATES
Number (%) of positive isolates by PCR#
Siderophore
system (PCR
target)
Ybt (ybtS)
All Sites
(n = 129)
22 (17)
Respiratory
(n = 33)
Nonrespiratory
(n = 96)
p*
Relative Risk*
(95% C.I.)
11 (33)
11 (11)
0.0068
2.4 (1.39 to 4.26)
Gly-Ent (iroN) 3 (2)
1 (3)
2 (2)
1.0
1.3 (0.26 to 6.85)
Ent
(entB/entE)
33 (100)
96 (100)
ND
ND
129 (100)
THE INTERACTION BETWEEN SIDEROPHORES
AND LIPOCALIN 2 DETERMINES THE PATTERN
OF PNEUMONIA
Bachman, M.A., Lenio, S., Schmidt, L. et al 2012 Submitted.
LIPOCALIN 2 BOUND TO ENTEROBACTIN
TRIGGERS INFLAMMATION
+ LCN2
NELSON ET AL. INFECTION AND IMMUNITY 2007
ENT-LCN2 MAY ALTER GENE
EXPRESSION VIA HYPOXIA-RESPONSE
PATHWAYS
Rank
Transcription
Factor
Gene
Ontology
Category
# genes
# hot
genes
p-value
estimated
FDR
MIR-506
11 glycolysis
606
44
25
9
1.36E-07
5.57E-09
0
0
HIF1
22 response
to hypoxia
167
160
11
14
7.29E-06
3.28E-08
0
0
FOXO4
33 endoplasmic
reticulum
1531
928
39
33
1.09E-05
2.80E-07
0.0033
0
44 endoplasmic
reticulum unfolded protein response
AP1
22
204
6
11
3.36E-07
4.71E-05
0
0.0075
5 cholesterol biosynthetic process
5 AP1
28
860
6
25
1.59E-06
6.31E-05
0
0.006
R. KUICK,
S. LENIO,
V. HOLDEN
HIF-1α
•INDUCED BY HYPOXIA OR IRON CHELATION
•REGULATES:
•MYELOID CELL FUNCTION
•PRO-INFLAMMATORY CYTOKINE SIGNALING (TNF)
•CELL SURVIVAL/APOPTOSIS
•ANGIOGENESIS (VEGFA)
CRAMER ET AL. 2003 CELL; PEYSSONNAUX ET. AL 2007 J IMMUNOL; WALMSLEY ET. AL 2011 JCI
ACKNOWLEDGEMENTS
Pathology/ U of M
Jeff Warren
Jay Hess
Lindsay Schmidt
Rork Kuick
Harry Mobley
Bachman Lab
Clinical Micro Lab
Steve Lenio
Duane Newton
Victoria
Holden
Rosemary Hankerd
The Molecular Team
NIH/NIGMS
K08 Career
Development Award
TEST METHODOLOGY
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Real-Time PCR
Closed System (low cross-contamination risk)
 Simultaneous Amplification and Detection of RNA or
DNA
 Quantitative or Qualitative
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