1.Diagnosis of tuberculous meningitis: challenges and promises
Noraini Philip ; Timothy William ; Daisy Vanitha John
The Malaysian Journal of Pathology 2015;37(1):1-9
Tuberculosis (TB) which is caused by Mycobacterium tuberculosis infects primarily the lungs but
it also affects other parts of the body. Tuberculous meningitis (TBM) is the most severe form of
TB and has the highest mortality and morbidity rate compared to other forms of TB. It is common
in young children and HIV-infected patients, but is also seen in adults. Despite anti-tuberculosis
treatment, TBM is still a major cause of death and neurological sequelae as treatment given to the
patients is often delayed. Early diagnosis is challenging due to the non-specific symptoms of TBM
and the low number of tubercle bacilli in cerebrospinal fluid (CSF). Until now, there is no established
diagnostic method that can rapidly detect M. tuberculosis in TBM patients with high sensitivity and
specificity. The emergence of drug resistant M. tuberculosis strains further complicates the diagnosis
and treatment regimen of TBM. This review summarizes challenges of the currently used diagnostic
methods and the potential future use of molecular diagnostic methods for TBM.
2.Leptospirosis: recent incidents and available diagnostics – a review
Yuszniahyati Yaakob ; Kenneth Francis Rodrigues ; Daisy Vanitha John
The Medical Journal of Malaysia 2015;70(6):351-355
Objective: The aim of this article was to review published
research articles on leptospirosis, in particular the recent
incidence of leptospirosis in Malaysia and the currently
available diagnostic methods for the detection of
leptospirosis.
Methods: PubMed, Google Scholar and Google Search
databases were searched using the key words Leptospira
and leptospirosis. A total of seventy-six references were
reviewed including sixty-seven research articles, three
annual reports from Ministry of Health and six online
newspaper articles. This review includes the following five
sub-headings: introduction, leptospirosis transmission,
leptospirosis incidents, laboratory diagnosis of
leptospirosis and treatment and prevention of leptospirosis.
Results: An increase in incidents of leptospirosis cases has
been seen in recent years in Malaysia. The recent floods
have contributed to the rise in the number of reported cases.
Current diagnostic approaches such as dark field
microscopy, microscopic agglutination test (MAT),
Polymerase chain reaction and serological tests are
inadequate as the organism is a slow grower.
Conclusion: There is an urgent need to develop newer
techniques for rapid detection of leptospirosis. The
combination of PCR and ELISA are suggested for rapid and
accurate diagnosis of leptospirosis. Studies on the
mechanism of pathogenesis of Leptospira are needed for
the development of vaccines that are safe for human use.
3.Characteristics, Detection And Typing Methods Of Community Acquired Methicillin Resistant Staphylococcus Aureus (CA-MRSA) – A Review
Lia Natasha Amit ; Fong Siew Moy ; Daisy Vanitha John
Malaysian Journal of Public Health Medicine 2017;17(3):27-37
Staphylococcus aureus aregram positive cocci which colonizethe skin and mucous membranes particularly the anterior nares. Prevalence of nosocomial infections associated with methicillin resistant S. aureus have been reported in hospitals (HA-MRSA) for over five decades. Recently,community-acquired MRSA (CA-MRSA) has emerged as a cause of skin and soft tissue infections in healthy individuals. These strains are sensitive to antimicrobials, carry genes for Panton-Valentine leukocidin (PVL) toxin and belong to the staphylococcal cassette chromosome (SCC) mec type IV or V. The suspected mode of transmission involves close contact with carriers leading to skin or nasal colonization that resultin subsequent active infection. Molecular typing is used to determine the mode of transmission of CA-MRSA in the community.General typing methods such as pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) and specific methods for Staphylococci such as SCCmec typing and spa typing have the capability to characterize bacterial chromosomes and mobile genetic elements. Combination of these molecular typing methods is necessary as each method has its own advantages with respect to discriminatory power, rapidity, cost effectiveness, reproducibility, and ease of performance.
CA-MRSA
;
prevalence
;
transmission
;
PVL toxin
;
SCCmec
;
spa typing
;
PFGE
;
MLST
4.Recombinant LipL32 Protein Developed Using a Synthetic Gene Detects Leptospiraspecific Antibodies in Human Serum Samples
Yuszniahyati Yaakob ; Kenneth Francis Rodrigues ; , Fernandes Opook ; Timothy William ; Daisy Vanitha John
Malaysian Journal of Medical Sciences 2017;24(5):44-51
Background: Synthetic biology is emerging as a viable alternative for the production of recombinant antigens for diagnostic applications. It offers a safe alternative for the synthesis of antigenic principles derived from organisms that pose a high biological risk. Methods: Here, we describe an enzyme-linked immunosorbent assay (ELISA) using the synthetic recombinant LipL32 (rLipL32) protein expressed in Escherichia coli for the detection of Leptospira-specific antibodies in human serum samples. The rLipL32-based ELISA was compared with a microscopic agglutination test (MAT), which is currently used as the gold standard for the diagnosis of leptospirosis. Results: Our results showed that all the MAT-positive serum samples were positive for Leptospira-specific IgG in an ELISA, while 65% (n = 13) of these samples were also positive for Leptospira-specific IgM. In the MAT-negative serum samples, 80% and 55% of the samples were detected as negative by an ELISA for Leptospira-specific IgM and IgG, respectively. Conclusion: An ELISA using the synthetic rLipL32 antigen was able to distinguish Leptospira-specific IgM (sensitivity 65% and specificity 80%) and IgG (sensitivity 100% and specificity 55%) in human serum samples and has the potential to serve as a rapid diagnostic test for leptospirosis.
5.Cytokine profile of patients with leptospirosis in Sabah, Malaysia
Mohammad Iskandar Bin Jumat ; Timothy WILLIAM ; Daisy Vanitha JOHN
The Medical Journal of Malaysia 2018;73(2):106-109
Background: Leptospirosis is a zoonotic disease withsymptoms ranging from a mild, febrile illness to a severeform with multiorgan failure. Severe leptospirosis mayrequire medical interventions in the form of dialysis and/ormechanical ventilation and often leads to mortality. Anexaggerated host immune response—in particular, a“cytokine storm”—that causes endothelial and organdamage is associated with the disease severity andmortality.Methods: Microscopic agglutination test (MAT)-positive andMAT-negative human serum samples (n=30) from patientswith leptospirosis were obtained from the Public HealthLaboratory, Kota Kinabalu, Sabah, Malaysia and controlserum samples (n=10) were obtained from healthy studentvolunteers. We estimated the levels of IL-1β, IL-6, IL-8, IL-10,and TNF-α in serum samples by a Luminex assay.Results: The levels of IL-6, IL-8, and IL1-β were significantlyhigher in 13% of the patients with leptospirosis compared tothe healthy controls, while the levels of IL-10 and TNF-α werenot elevated in either group.Conclusion: Our data suggest that elevated levels of IL-6, IL-8, and IL1-β may be associated with leptospirosis diseaseseverity, which requires patient follow-up for confirmation.