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Winter 2012
Doctors’ Newsletter
Page 2
The pathologists of DHM & BSP
Dr Colin Goldschmidt
Pages 3-4
New Pathologists
Pages 5-6
Clostridium difficile Infection
Dr Ian Chambers
Page 7
Dr Michael Wehrhahn
Pages 8-9
Chlamydia trachomatis infection
Dr Ian Chambers
Pages 10-11
Rapid Identification of Bacterial
Pathogens by MALDI-TOF Mass
Dr Michael Wehrhahn
Dr Ian Chambers
The pathologists of DHM & BSP
The pathologists of Douglass Hanly Moir Pathology (DHM) and
Barratt & Smith Pathology (BSP) operate at the heart of our
operations, the laboratory. As directors and supervisors of the
lab, they assure the integrity of our results by assessing and
monitoring our methods, systems, quality control, staff and
equipment. They analyse results and provide interpretative
comments. And they teach.
Dr Colin Goldschmidt
Chief Executive Officer
As the essential link between clinician
and laboratory, our pathologists
spend much of their time in telephone
consultation with clinicians, providing
assistance with the interpretation of
results and offering assistance in the
area of clinico-pathological correlation.
They are directly involved in all labrelated management decisions and,
under our commitment to ‘medical
leadership’, they play a pivotal role in
shaping all decisions in the company.
We remain ever-committed to operating
DHM and BSP as a Medical Practice,
rather than purely as a business. In this
way, quality, service, ethical practice
and good medicine will prevail.
DHM and BSP employ far more
pathologists than any other pathology
company in NSW. Over the past
two decades, we have developed
specialised expertise in almost all
areas of laboratory testing, largely as a
result of the expertise and specialised
makeup of our pathologist team,
which has expanded in tandem with
the growth of the practice. In this
edition of the Doctors’ Newsletter, we
introduce to you a group of new DHM
pathologists who have recently joined
the practice and whom we welcome
most warmly.
If you thought that all pathologists were
the same, then think again! At DHM
and BSP we have haematologists,
chemical pathologists, microbiologists,
immunologists, genetic pathologists,
histopathologists, cytopathologists,
gynaecological pathologists,
dermatopathologists, uropathologists,
neuropathologists and others. We even
have one pseudopathologist – that’s
me, in my administrative, non-practising
role in the practice!
We encourage you to call our
pathologists at any time. When you call,
you will be directed to the pathologist
of your choice or to a specialist
pathologist who is most appropriate
for your particular enquiry. And finally,
if you wish to discuss any matter that
matches my ‘speciality’, I shall be
delighted to take your call myself!
Thank you for your support of our
pathology practice.
With my warmest regards,
Dr Colin Goldschmidt
Douglass Hanly Moir Pathology
Barratt & Smith Pathology
New Pathologists
Specialty: Histopathology
Special interests: Ocular, gastrointestinal, urological, breast and skin pathology
Dr Alex Allende is a medical graduate of the University of Sydney. Following extensive experience
in clinical medicine for several years, with particular interests in ophthalmology and research, she
undertook a Doctorate of Philosophy in the discipline of ophthalmology at the University of Sydney,
with the support of an NHMRC scholarship. The thesis, incorporating histological and molecular
studies into the mechanisms of vascular development in the choroid and retina, inspired her to train in
anatomical pathology, which was undertaken primarily at Westmead Hospital, with additional rotations
to Nepean Hospital and Douglass Hanly Moir Pathology. Following completion of training, which
included teaching, journal publications and conference presentations, she joined the histopathology
department at Douglass Hanly Moir and is developing her knowledge further by following interests in
ocular, gastrointestinal, urological, breast and skin pathology.
Specialty: Histopathology
Special interests: Pulmonary, breast and gastrointestinal pathology, dermatopathology and
Dr Juliet Burn graduated from the University of New South Wales in 1980 and obtained her
Fellowship of RCPA in 1987. She joined the small independent practice, Davies Campbell de Lambert
Pathology, in 1988 and became a principal in 1991. Dr Burn held Visiting Medical Officer positions
at Auburn Hospital and ICPMR Westmead, from 1988 until 2006. She has held positions on the
Board of Censors RCPA and, since 1993, she has been regularly involved in quality assurance in
pathology in Australia and overseas. Dr Burn has extensive experience in teaching and supervision
of RCPA pathology registrars and in participation in multidisciplinary meetings (dermatopathology,
gastrointestinal and breast pathology). She also has extensive experience in diagnostic histopathology
and cytology, with a special interest in skin, breast, lung and gastrointestinal pathology.
Specialty: Histopathology
Special Interests: Dermatopathology, melanoma and inflammatory skin disorders
As an undergraduate at the University of Sydney from 1960 to 1965, when pathology was a
major component of the medical course, Dr Robert Cortis-Jones decided he wanted to become a
pathologist. Most of his post-graduate training in pathology was at Sydney Hospital, which was, at
that time, the location of the Melanoma Unit, making melanoma a significant professional interest for
him. He completed his pathology training in 1973 and then spent two-and-a-half years in tropical
Townsville, at the Australian Government Pathology laboratory. This further increased his interest
in skin tumours, particularly melanoma. Dr Cortis-Jones moved to Wollongong as the Director of
Anatomical Pathology for the Illawarra Area Health Service from 1984 to 2000, covering almost all
areas of Anatomical Pathology. Returning to Sydney, and now happy to specialise in just one area,
from 2002 to 2010 he was a pathologist at Combined Pathology, Gordon. This laboratory served skin
cancer clinics across Australia, from Brisbane to Perth. Dr Cortis-Jones joined Douglass Hanly Moir
Pathology in October 2010, after Combined Pathology was bought by Sonic Healthcare. During his
career, he has seen major changes in the early diagnosis of melanoma, the result of collaboration
between pathologists, both in Australia and abroad, and the great benefits of early diagnosis and
treatment Dr Cortis-Jones is now looking to increase his expertise in inflammatory skin disorders.
Speciality: Histopathology
Special Interests: Dermatopathology and education
Dr Simon Clark graduated from the University of Otago, New Zealand. His training in pathology and
histopathology began in Wellington Hospital and was completed at Royal Melbourne Hospital. Dr
Clark completed a Fellowship of Dermatopathology at the Skin and Cancer Foundation, Sydney.
He has worked in public and private pathology and has lectured at the University of Melbourne and
the University of Queensland. Dr Clark continues to be extensively involved in general practitioner
education in skin cancer medicine. He presently runs the pathology component of the post-graduate
certificate courses in skin cancer medicine at the University of Queensland and also lectures in the
Masters of Medicine course. Dr Clark joined Douglass Hanly Moir Pathology in October, 2011.
New Pathologists
Specialty: Histopathology
Special interests: Breast and genitourinary
Dr Lisa Lin graduated from University of New South Wales in 2004 and completed her internship and
residency training at Royal Prince Alfred Hospital, Sydney. She commenced her anatomical pathology
training at John Hunter Hospital, Newcastle, in 2007, after which her training was predominantly
based at Westmead Hospital, Sydney. Dr Lin also gained experience working at different public and
private laboratories through rotations to Douglass Hanly Moir Pathology, Royal North Shore and
Nepean Hospitals and the Department of Forensic Medicine, Glebe. During her training, Dr Lin has
been involved in a number of publications in peer-review journal articles, and also co-authored a
textbook chapter. She has special interests in breast, genitourinary and gynaecological pathology.
Special interest: Genetic pathology
Dr Scott Mead graduated from the University of Auckland (New Zealand) where he also gained a PhD
in Molecular Medicine. His pathology training was undertaken at Christchurch School of Medicine
(University of Otago) and Royal Prince Alfred Hospital, Sydney. Dr Mead has a long-standing interest
in cancer genetics and is currently researching the clinical application of personal cancer genome
sequencing at the Kinghorn Cancer Centre (Garvan Institute). He is also involved in targeted oncology
testing at SydPath Pathology (St Vincent’s Hospital). Dr Mead is currently aConjoint Senior Lecturer at
the School of Medical Sciences, University of NSW.
Speciality: Haematology
Special interests: Malignant haematology, flow cytometry and molecular genetics
Dr Craig Wallington-Beddoe graduated with a medical degree from the University of Sydney in
2001. During his early medical training, he developed an interest in haematology and undertook
postgraduate clinical and laboratory haematology training at Prince of Wales and Westmead
Hospitals for the awards of FRACP and FRCPA in 2010. Dr Wallington-Beddoe is currently
completing his PhD studies in acute lymphoblastic leukaemia (ALL) research at the Westmead
Millennium Institute, the University of Sydney. His study is investigating the function of enzymes
called sphingosine kinases in maintaining viable ALL cells and attempting to exploit these enzymes
and their associated intracellular signalling pathways to provide a novel approach to treating ALL.
Dr Wallington-Beddoe joined Douglass Hanly Moir’s haematology department in November 2011.
His interests are in malignant haematology, with a particular focus on leukaemias and lymphoid
neoplasms, and he is familiar with a wide range of laboratory techniques and their applications to
clinical haematology.
Specialty: Microbiology
Special interests: Clinical infectious diseases and diagnostic microbiology
After graduating from the University of NSW in 1999, Dr Michael Wehrhahn completed a Master of
Public Health at the University of Sydney before commencing training in Clinical Microbiology and
Infectious Diseases in Perth, in 2005. Experience gained at Royal Perth, Fremantle and Princess
Margaret Hospitals was complemented by appointments at Liverpool, Royal North Shore and
Westmead Hospitals, where he completed his training in mid-2011.
Dr Wehrhahn has developed several specific interests and areas of expertise. For the last two
years, he has worked as a clinical mentor to HIV providers in the Highlands of Papua New Guinea,
in addition to maintaining research interests in the clinical and laboratory features of communityassociated MRSA, novel diagnostic methods for identifying fastidious bacteria and identifying
preventable factors associated with health-care associated infections.
He holds a current appointment as Adjunct Lecturer at the University of Notre Dame, Sydney.
Clostridium difficile Infection
Clostridium difficile is an anaerobic Gram-positive, spore-forming
bacillus, identified first as normal bowel flora in healthy neonates
but, over time, recognised as a potential gastrointestinal pathogen of
major clinical and cross-infection significance. Disease is related to
the production of two potent exotoxins: toxin A ("enterotoxin") and
toxin B ("cytotoxin"), which cause intestinal fluid secretion, mucosal
injury and inflammation.
Toxin B is the essential virulence factor of C. difficile, however, being
approximately ten times more potent than toxin A.
Dr Ian Chambers
C. difficile is the causative organism
of antibiotic-associated colitis and
diarrhoea, and is a cause of significant
morbidity (and occasional mortality)
especially, but not exclusively, among
hospitalized patients. Antibiotic
administration is the most widely
recognized risk factor for C. difficileassociated diarrhoea (CDAD) but other
risk factors include hospitalization,
advanced age, concurrent severe
illness, chemotherapy etc. CDAD can
also occur without any risk factor being
The main clinical features of C. difficile infection are watery
diarrhoea, abdominal pain, low
grade fever and leucocytosis,
although the clinical spectrum
ranges from asymptomatic carriage
to severe fulminant disease and
toxic megacolon. Illness is generally
in the setting of current or recent
antibiotic administration, but
onset may be days or weeks after
antibiotic treatment has stopped. The
antibiotics most frequently implicated
are fluoroquinolones, clindamycin,
cephalosporins, and penicillins,
but virtually all antibiotics, including
metronidazole and vancomycin, have
been associated with CDAD.
Over the last decade, hospital-acquired
C. difficile infection has become a major
problem worldwide, with the incidence
and severity of healthcare-associated
disease increasing dramatically. Several
factors are involved in this, including
the high carriage rates of C. difficile
in hospitalised adults (~30%) and its
easy transmissibility via fomites. A more
virulent strain of C. difficile has also
emerged in that time. This strain (C. difficile ribotype 027) causes a more
severe illness which can be refractory
to standard therapy and is more likely
to relapse than that caused by other
strains. Its hypervirulence may be
due to its substantially greater toxin
production compared to conventional
strains, and a strong correlation
exists between its emergence and
the increased use of fluoroquinolone
Clostridium difficile Infection
Laboratory Tests for CDAD
The two main approaches to the diagnosis of C. difficile infection are detection of
the organism itself and detection of the toxin(s) it produces. Until recently no method
with the necessary diagnostic sensitivity and specificity was also rapid, simple and
inexpensive enough for routine use.
Organism detection assays (including antigen testing and culture) have the inherent
problem that some C. difficile strains are non-toxigenic. Up to 30 percent of
hospitalized patients are colonized by C. difficile without having disease and therefore
the presence of the organism by itself does not prove pathogenicity.
Enzyme immunoassay (EIA) for either toxins A and B combined or toxin B alone
is the method in widest use. While specificity is generally good and false-positives
uncommon, the diagnostic sensitivity of these assays is only moderate and the falsenegative rate is unacceptably high. EIA should not be used for the investigation of
possible CDAD.
Polymerase Chain Reaction (PCR) provides greatly enhanced diagnostic sensitivity for CDAD. The tcdB gene of C. difficile
(which encodes toxin B) is considered to be its primary virulence factor and is present in virtually all diarrhoeagenic strains,
including the hypervirulent O27 ribotype. Detection of the tcdB gene by PCR provides rapid and accurate diagnosis, which in
turn allows prompt implementation of treatment and infection control measures. PCR overcomes the disadvantages inherent in
other methods and has recently been introduced at Douglass Hanly Moir Pathology for the diagnosis of CDAD.
Several aspects of this assay should be emphasised
CDAD is associated with current or recent antibiotic administration
and/or recent hospitalisation and testing for C. difficile is appropriate
when such risk factors are present in an individual with diarrhoea. It
is not a common cause of sporadic, community-acquired diarrhoeal
illness in otherwise healthy individuals and testing for it should not be
included in the initial laboratory investigations of such patients.
The tcdB PCR test is appropriate for use only on unformed stool
from patients with clinically significant diarrhoea. Certain patient
groups (eg current or recent hospital inpatients and infants in the first
year of life) have high rates of asymptomatic carriage of toxigenic C. difficile and such individuals do not require treatment. Formed stool should only be tested in exceptional circumstances.
The high diagnostic sensitivity of the tcdB PCR provides reliable,
single-sample diagnosis of CDAD. If an initial result is negative the
diagnostic yield is not significantly increased by testing another
Nucleic acid remains detectable for several weeks after effective
treatment for CDAD, making test-of-cure unnecessary and possibly
misleading. An exception to this is in the context of relapsing illness.
If possible, specimens should be refrigerated until transported
to the laboratory. Specimens are stable for up to 2 days at room
temperature and 5 days if refrigerated at 4˚C.
Faecal specimens may occasionally contain factors which inhibit the
PCR process. If such inhibition is found and cannot be resolved,
repeat collection should be considered.
PCR represents a major advance in the diagnosis of C.difficile-associated disease. Douglass Hanly Moir Pathology
is pleased to be able to provide this test as the primary investigation for this condition.
For further information, or to discuss a patient please contact Dr Ian Chambers or Dr Miriam Paul on 98 555 312
Bordetella parapertussis, like B. pertussis, is a recognised cause of
whooping cough in all ages and, in some countries, causes up to
one-third of whooping cough cases.
The clinical presentation is similar to
that of B. pertussis but is generally
milder, with the majority of patients
having a cough lasting less than a week
and entire illness that resolves within
a month. The “whoop” is a feature in
up to 60% of cases and post-tussive
vomiting in up to 40% of cases.
Dr Michael Wehrhahn
The reduced severity of parapertussis
infection is thought to be related to a
lack of key virulence factors, such as
pertussis toxin (PT), that are found in B.
pertussis. There is no cross immunity
between pertussis and parapertussis
and, as the components in the current
pertussis vaccine target toxins like
PT, the vaccine has limited, if any,
protection against parapertussis.
In those with severe disease caused
by B. parapertussis, one can expect
clinical improvement from the same
antibiotics recommended for the
treatment of B. pertussis.
 Integrated Cycler for
detection of B. pertussis and
B. parapertussis
No data is available with regard to
the value of prophylaxis for highrisk contacts of patients with B.
parapertussis and it is not a notifiable
disease, in contrast to B. pertussis.
 Child with whooping cough
While culture, in the past, has been
the main way of differentiating these
two species, few laboratories in
Australia still culture for B. pertussis/
parapertussis. At DHM, the recent
introduction of a real-time multiplex
PCR that detects B. pertussis and
B. parapertussis simultaneously has
allowed the diagnosis of an additional
proportion of whooping cough cases.
This test is performed Monday to Friday
with a result expected within 24 hours.
Diagnosis of parapertussis may prevent
unnecessary further investigation of a
patient’s cough illness and support the
decision to treat with antibiotics.
For further information, or to discuss a patient please contact
Dr Michael Wehrhahn on 98 555 287
Chlamydia trachomatis infection
Chlamydia trachomatis is the most commonly notified sexually
transmissible bacterial disease in Australia, with annual casenotifications doubling since the early 1990s. It affects both genders,
with approximately 75% of reported infections occurring in those
aged less than 30 years. It is also the most common infective
cause of pelvic inflammatory disease and subsequent female-factor
infertility in Australian women. Several countries have instituted
screening programs in asymptomatic young women to prevent such
long-term complications of this infection. Risk factors for chlamydia
infection include multiple sexual partners, a recent change in sexual
partner and non-use of barrier contraceptives, such as condoms.
Endocervical C. trachomatis infection has also been associated with
an increased risk of acquiring HIV infection and may also increase
HIV infectiousness.
Dr Ian Chambers
Mode of transmission
This is predominantly by sexual
contact, but occasionally from mother
to baby during vaginal delivery. The
high proportion of asymptomatic cases
results in untreated infection, ongoing
transmission and increased incidence
of long-term sequelae.
Diagnosis of genitourinary C. trachomatis infection
RACGP guidelines recommend annual
testing for all sexually active 15-25
year-olds, including those who are
asymptomatic. Screening for chlamydia
can be opportunistic, that is, when the
patient presents for unrelated reasons.
Polymerase Chain Reaction (or one
of the other nucleic acid detection
methods available) is the test of choice
for diagnosing C. trachomatis and a
variety of specimens can be suitable.
The preferred specimen for Chlamydia
testing in men is urine, rather than a
urethral swab. A properly collected
male urethral swab causes discomfort,
which means that most male urethral
swabs are not properly collected and
give inferior results, compared to urine.
The requirements for a first-void urine,
as opposed to a mid-stream, and that
an hour should have elapsed since
last passing urine, have become more
relaxed over time because of the very
high sensitivity of the methods currently
used for diagnosis.
Urine is collected in the usual
yellow-top urine jar. Urine is also
an acceptable specimen for routine
chlamydia testing in women, although
if a speculum examination is being
conducted, then a swab taken from the
endocervix is recommended.
Testing for chlamydia in women can
also be performed on a low vaginal
swab. This does not require the use
of a speculum and the swab can be
self-collected by patients if they wish
to do so.
A dry swab (ie, a swab for which
the transport tube contains no
liquid medium) is recommended for
chlamydia PCR. If available, a ‘flocked’
swab is better than a standard swab
because it collects more material.
Flocked swabs are available from the
Stores department.
If a ThinPrep liquid cytology vial has
been collected, this specimen is also
suitable for use in the C. trachomatis
and N. gonorrhoeae PCR tests.
Despite advice to the contrary from
some professional groups, the growing
incidence of gonorrhoea suggests
that this diagnosis should also be
considered when testing for C.
trachomatis is undertaken. The same
specimen can be used for both tests.
Re-testing for C. trachomatis
Test-of-cure is not usually
recommended after treatment, except
when the patient is pregnant or unless
there is persistence of symptoms.
Repeat testing is indicated, however, if
there is a continuing risk of re-infection.
Serology for C. trachomatis
The diagnosis of genital chlamydia
infection cannot be confirmed or
excluded serologically. Serology has
no useful role in this situation: it is not
accurate and should not be done.
Chlamydia trachomatis PCR is
performed daily, using the Roche cobas
4800 instrument.
Chlamydia trachomatis infection
 The Roche Cobas 4800
instrument automates
C.trachomatis and
N.gonorrhoeae PCR testing
Coloured transmission
electron micrograph (TEM) of
Chlamydia trachomatis bacteria
(purple) inside a cell (yellow).
Magnification: x5000 when
printed 10cm wide 
For further information, or to discuss a patient please contact Dr Ian Chambers or Dr Miriam Paul on 98 555 312
Rapid Identification of Bacterial Pathogens by
MALDI-TOF Mass Spectroscopy
Not many deliveries to Douglass Hanly Moir Pathology of large,
shiny machines encased in bubble-wrap are addressed to the
Microbiology Laboratory, but that day has come at last.
Douglass Hanly Moir Pathology is the first private laboratory in
Australia to begin using an instrument that is amongst the most
sophisticated available for the rapid and reliable identification
of bacterial and fungal pathogens. MALDI-TOF (Matrix-Assisted
Laser Desorption Ionisation – Time of Flight) technology uses mass
spectroscopy (MS) to analyse bacterial and fungal cultures. This not
only allows much faster identification of potential pathogens, but
provides greater certainty of that identification.
Dr Ian Chambers
Dr Michael Wehrhahn
MALDI-TOF-MS relies on the
premise that virtually every bacterial
species, when analysed using mass
spectroscopy, has a unique “protein
signature”, based on mass-charge
ratio. Microbial identification is achieved
by comparing the mass spectral
profile of the test organism with a
database consisting of more than 500
medically important bacteria and 70
relevant fungi. If the required level of
concordance is reached between test
and reference profiles, identification has
been achieved.
Routine use of this technology, over
the last decade in Europe and more
recently worldwide, has established its
clinical utility. More rapid identification of
pathogens (taking minutes rather than
the 4-24 hours required by traditional
identification methods) has translated
into improved clinical outcomes.
Rapid Identification of Bacterial Pathogens by
MALDI-TOF Mass Spectroscopy
 Vitek MS: Faster identification of pathogens
and improved management of sepsis.
On average, it is anticipated that the identification and reporting
of most organisms will take a day less than is currently
possible. While formal antibiotic susceptibility testing is still
required, rapid pathogen identification allows empiric antibiotic
selection to be made with greater confidence and appropriate
antibiotic selection leads to improved clinical outcomes.
This is of greatest importance in critical conditions, such as
bacteraemia and sterile-site infections, but treatment and
outcomes of less critical conditions, such as soft-tissue and
urinary tract infection, will also be improved.
MALDI-TOF-MS will also shorten the time it takes to report
uncommon and difficult-to-identify organisms which are
currently sent to reference laboratories. In many cases, this
will shorten the identification-time from a week or more to the
same day the culture becomes positive.
The introduction of MALDI-TOF-MS technology represents a
fundamental shift in the approach to diagnostic microbiology.
In an area of pathology where oxgall, rabbit plasma and fetal
bovine serum are still essential reagents for the identification of
bacteria and fungi, a shiny new machine is a welcome addition.
For further information, or to discuss a patient please contact
Dr Ian Chambers on 98 555 330 or Dr Michael Wehrhahn on 98 555 287
A trading name of DOUGLASS HANLY MOIR PATHOLOGY PTY LIMITED • ABN 80 003 332 858
A subsidiary of SONIC HEALTHCARE LIMITED • APA ABN 24 004 196
TEL (02) 4734 6500 • FAX (02) 4732 2503
A subsidiary of SONIC HEALTHCARE LIMITED • APA ABN 24 004 196 909
TEL (02) 98 555 222 • FAX (02) 9878 5077