1.Comparison of BBL chromagar MRSA to conventional media for the detection of methicillin resistant staphylococcus aureus in surveillance nasal swabs
N Mohd Noor ; S Thevarajah ; Zubaidah Abdul Wahab ; S H Hussein
Malaysian Journal of Dermatology 2008;21(-):81-86
Objectives This study aims to detect MRSA nasal carriers among medical staff and patients in Dermatology ward Hospital Kuala Lumpur by using two methods, the conventional blood sheep agar (BSA) and the novel BBL CHROMagar MRSA (C-MRSA). It also aims to compare the BSA medium with the C-MRSA medium in terms of specificity, sensitivity and time to detection to MRSA.
Method A single centre, prospective study where 100 nasal swab samples were taken from medical staff and inpatients, then plated on to both BSA and C-MRSA. After 24 hours incubation, the plates were examined for presence of bacterial colonies, then incubated for another
24 hours if no colonies were present. All colonies on C-MRSA and BSA were subjected to coagulase and susceptibility testing for confirmation of MRSA. MRSA strains produce mauve colonies on CMRSA
from hydrolysis of the chromogenic substance, thus C-MRSA
uses colour as a diagnostic tool.
Results Mauve colonies were present on nine C-MRSA plates in the first 24 hours which were all confirmed to be MRSA. Another nine CMRSA plates isolated bluish colonies which were not MRSA. There were colonies on 96 BSA plates, nine of which were MRSA. C-MRSA medium has 100% sensitivity and specificity in detecting MRSA. Both culture media had similar detection rates of MRSA from nasal swabs,
however C-MRSA allows for earlier detection of MRSA within 24 hours compared to BSA which takes 48 hours. 2.2% of ward staff and 15.7% of inpatients were found to be MRSA carriers.
Conclusion CHROMagar MRSA allows for more rapid
identification of MRSA carriers within 24 hours compared to the conventional BSA which takes 48 hours. This allows earlier action to be taken to reduce the spread of MRSA infection.
2.A comparative evaluation of dengue diagnostic tests based on single acute serum samples for laboratory confi rmation of acute dengue
CHUA KB ; MUSTAFA B ; ABDUL WAHAB AH ; CHEM YK ; KHAIRUL AH ; KUMARASAMY V ; MARIAM M ; NURHASMIMI H ; ABDUL RASID K
The Malaysian Journal of Pathology 2011;33(1):13-20
A prospective study was carried out to evaluate the sensitivity of dengue NS1 antigen-capture
ELISA in comparison with dengue virus isolation, conventional RT-PCR and real-time RT-PCR for
laboratory confi rmation of acute dengue based on single-acute serum samples. Four primary healthcare
centres were involved to recruit patients with clinical diagnosis of dengue illness. Patient’s
demographic, epidemiological and clinical information were collected on a standardized data entry
form and 5 ml of venous blood was collected upon consent. In the laboratory, six types of laboratory
tests were performed on each of the collected acute serum sample.
Of the 558 acute serum samples collected from 558 patients with clinical diagnosis of dengue
from mid-August 2006 to March 2009, 174 serum samples were tested positive by the dengue NS1
antigen-capture ELISA, 77 by virus isolation, 92 by RT-PCR and 112 by real-time RT-PCR. A total
of 190 serum samples were tested positive by either one or a combination of the four methods
whereas, only 59 serum samples were tested positive by all four methods. Thus, based on singleacute
serum samples, 190 of the 558 patients (34.1%) were laboratory-confi rmed acute dengue. The
overall test sensitivity was 91.6%, 40.5%, 48.4% and 58.9% for dengue NS1 antigen-capture ELISA,
virus isolation, conventional RT-PCR and real-time RT-PCR respectively. Statistically, dengue NS1
antigen-capture ELISA was the most sensitive and virus isolation was the least sensitive test for the
laboratory confi rmation of acute dengue based on single-acute serum specimens. Real-time RT-PCR
was signifi cantly more sensitive than the conventional RT-PCR.
3.Plasmodium falciparum protein kinase as a potential therapeutic target for antimalarial drugs development
Mahmud, F. ; Lee, P.C. ; Abdul Wahab, H. ; Mustaffa, K.M.F. ; Leow, C.H. ; Azhar, R. ; Lai, N.S.
Tropical Biomedicine 2020;37(No.3):822-841
Malaria is one of the most dangerous infectious diseases due to its high infection and mortality rates, especially in the tropical belt. Plasmodium falciparum (P. falciparum), the most virulent malaria parasite in humans, was recently reported to develop resistance against the final efficient antimalarial drug, artemisinin. Little is known about the resistance mechanisms, which further complicates the problem as a proper counteraction is unable to be taken. Hence, the understanding of drug mode of action and its molecular target is valuable knowledge that needs to be considered to develop the next generation of antimalarial drugs. P. falciparum protein kinase (Pf PK) is an attractive target for antimalarial chemotherapy due to its vital roles in all P. falciparum life stages. Moreover, overall structural differences and the presence of unique Pf PKs that are absent in human kinome, suggesting specific inhibition of Pf PK without affecting human cells is achievable. To date, at least 86 eukaryotic protein kinases have been identified in P. falciparum kinome, by which less than 40 were validated as potential targets at the erythrocytes stage. In this review, recent progress of the furthest validated Pf PKs; Pf Nek-1, Pf CDPK1, Pf CDPK4, Pf PKG, and Pf CLK-3 will be briefly discussed.
4.Natural DENV-2 NS2B/NS3 protease inhibitors from Myristica cinnamomea King
Sivasothy, Y. ; Liew, S.Y. ; Othman, M.A. ; Abdul Wahab, S.M. ; Hariono, M. ; Mohd Nawi, M.S. ; Abdul Wahab, H. ; Awang, K.
Tropical Biomedicine 2021;38(No.2):79-84
The NS2B/NS3 protease is crucial for the pathogenesis of the DENV. Therefore, the inhibition of this protease is considered to be the key strategy for the development of new antiviral drugs. In the present study, malabaricones C (3) and E (4), acylphenols from the fruits of Myristica cinnamomea King, have been respectively identified as moderate (27.33 ± 5.45 μM) and potent (7.55 ± 1.64 μM) DENV-2 NS2B/NS3 protease inhibitors, thus making this the first report on the DENV-2 NS2B/NS3 protease inhibitory activity of acylphenols. Based on the molecular docking studies, compounds 3 and 4 both have π-π interactions with Tyr161. While compound 3 has hydrogen bonding interactions with Gly151, Gly153 and Tyr161, compound 4 however, forms hydrogen bonds with Ser135, Asp129, Phe130 and Ile86 instead. The results from the present study suggests that malabaricones C (3) and E (4) could be employed as lead compounds for the development of new dengue antivirals from natural origin.