1.In vitro antibacterial activity of Quercus infectoria gall extracts against multidrug resistant bacteria
Wan Nor Amilah, W.A.W. ; Masrah, M., Hasmah, A. ; Noor Izani, N.J.
Tropical Biomedicine 2014;31(4):680-688
Antimicrobial activities of plants have long been evaluated for their promising use
as antimicrobial agent and in minimizing the unwanted resistance effects of microorganisms.
The study was conducted to evaluate the antibacterial activity of Quercus infectoria gall
crude extracts against multidrug resistant (MDR) bacteria in vitro. The screening test was
determined by disc diffusion technique using sterile filter paper discs impregnated with 1 mg/
disc (50 mg/ml) aqueous and ethanol extracts of Q. infectoria galls tested on five selected
MDR bacterial strains. The minimum inhibitory concentration (MIC) was determined using
the twofold serial micro dilution technique at concentration ranging from 5.00 mg/ml to 0.01
mg/ml. The minimum bactericidal concentration (MBC) was determined by sub culturing the
microtitre wells showing no turbidity on the agar plate to obtain the MBC value. Both extracts
showed substantial inhibitory effects against methicillin resistant coagulase negative
Staphylococcus (MRCoNS) and methicillin resistant Staphylococcus aureus (MRSA). A slightly
reduced inhibitory zone diameter was observed with MDR Acinetobacter sp. while no inhibitory
effect was displayed among the extended spectrum beta lactamases (ESBL) K. pneumoniae
and ESBL E. coli isolates. A significant difference in the zone sizes between both extracts
was only observed in MRSA (p < 0.05). The MIC values ranged from 0.08 mg/ml to 0.63 mg/ml
for aqueous and ethanol extracts against MRSA, MRCoNS and MDR Acinetobacter sp. while
their MBC to MIC ratio values were 2 and less. The Q. infectoria gall extracts have shown
very promising in vitro antibacterial activities and may be considered as a potentially good
source of antimicrobial agent especially against MDR Gram positive bacteria.
2.Direct tetrazolium microplate assay (TEMA) for rapid drug susceptibility test screening of Mycobacterium tuberculosis
Wan Nor Amilah, W.A.W. ; Mohammad Lukman, Y. ; Noor Izani, N.J.
Tropical Biomedicine 2016;33(4):814-823
Rapid and inexpensive assays for drug susceptibility testing (DST) of Mycobacterium
tuberculosis (MTB) are urgently required especially in developing countries where tuberculosis
cases are prevalent. In response to this necessity, a direct microplate-based colorimetric
assay which excludes the use of pre-testing culture isolate was evaluated. MTB susceptibility
to the first line anti-tuberculosis drugs was tested directly on sputum specimens using
tetrazolium microplate assay (TEMA) method and the sensitivity, specificity, accuracy as
well as mean turn-around time of TEMA were compared to the standard absolute concentration
method (ACM). TEMA was performed on 41 acid fast bacilli (AFB) positive sputum specimens
by direct inoculation of the processed specimens into the microplate wells containing serialdiluted
first line anti-tuberculosis drugs using tetrazolium dye as growth indicator. Indirect
TEMA was performed on MTB isolates of the corresponding samples. The minimum inhibitory
concentrations (MICs) of isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and streptomycin
(SM) were obtained for direct and indirect TEMA with reference to the absolute concentration
method (ACM). After establishing the breakpoint MIC of each drug using receiver operating
characteristics (ROC) curve, reliable results from direct TEMA were obtained for INH and
SM, with excellent levels of sensitivity, specificity, and accuracy (more than 90%). The
predictive values for susceptibility were 100% for INH, EMB and SM as well as 96% for RMP.
A shorter mean turn-around time of 14 days was observed for direct TEMA (P < 0.05). Thus
direct TEMA is potentially rapid, reliable and inexpensive DST screening method of MTB in
countries with high prevalence rates of drug resistance tuberculosis
3.Contamination of faecal coliforms in ice cubes sampled from food outlets in Kubang Kerian, Kelantan
Noor Izani, N.J. ; Zulaikha, A.R. ; Mohamad Noor, M.R. ; Amri, M.A. ; Mahat, N.A.
Tropical Biomedicine 2012;29(1):71-76
Abstract. The use of ice cubes in beverages is common among patrons of food outlets in Malaysia although its safety for human consumption remains unclear. Hence, this study was designed to determine the presence of faecal coliforms and several useful water physicochemical parameters viz. free residual chlorine concentration, turbidity and pH in ice cubes from 30 randomly selected food outlets in Kubang Kerian, Kelantan. Faecal coliforms
were found in ice cubes in 16 (53%) food outlets ranging between 1 CFU/100mL to >50 CFU/ 100mL, while in the remaining 14 (47%) food outlets, in samples of tap water as well as in commercially bottled drinking water, faecal coliforms were not detected. The highest faecal
coliform counts of >50 CFU/100mL were observed in 3 (10%) food outlets followed by 11-50 CFU/100mL and 1-10 CFU/100mL in 7 (23%) and 6 (20%) food outlets, respectively. All samples recorded low free residual chlorine concentration (<0.10mg/L) with the pH ranging between 5.5 and 7.3 and turbidity between 0.14-1.76 NTU. Since contamination by faecal coliforms was not detected in 47% of the samples, tap water and commercially bottled drinking water, it was concluded that (1) contamination by faecal coliforms may occur due to improper
handling of ice cubes at the food outlets or (2) they may not be the water sources used for making ice cubes. Since low free residual chlorine concentrations were observed (<0.10mg/L) in all samples as well as in both tap water and commercially bottled drinking water, with
the pH ranged between 5.5-7.3, ineffective disinfection of water source as a contributing factor to such high counts of faecal coliforms in ice cubes also could not be ruled out. Therefore, a periodical, yet comprehensive check on the food outlets, including that of ice cube is crucial in ensuring better food and water for human consumption.
4.A simple screening test for the detection of metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter in a tertiary care hospital
Wan Nor Amilah, W.A.W. ; Noor Izani, N.J. ; Ng, W.K. ; Ashraful Haq, J.
Tropical Biomedicine 2012;29(4):588-597
Clinical utilization of carbapenems remains under threat with the emergence of acquired carbapenemase-producing bacteria, particularly metallo-β-lactamases (MBL). Rapid
detection of MBL-producing Gram-negative bacilli is essential to prevent their widespread dissemination. However, no standardized detection method is available for routine laboratory use. The purpose of the study was to evaluate a chelating-agent based double disk synergic
test and disk potentiation test for MBL-producing strain detection and to determine the isolation rate of MBL-producing Pseudomonas aeruginosa and Acinetobacter from clinical samples in our tertiary teaching hospital. A total of 22 and 66 imipenem-resistant P. aeruginosa
and Acinetobacter isolates respectively were tested with ceftazidime (CAZ) disk by modified double disk synergic test and disk potentiation test using ethylenediaminetetraacetic acid (EDTA) and 2-mercaptopropionic acid (as chelating agents) to detect MBL production. The tests were compared with EDTA-phenanthroline-imipenem (EPI) microdilution MIC test as
gold standard. MBL positive strains were detected in 17 (77.3%) P. aeruginosa and 2 (3.5%) Acinetobacter isolates. The disk potentiation test with 2-mercaptopropionic acid (2-MPA) dilution of 1:12 provided the most acceptable sensitivities and specificities (88.2% sensitivity
and 100% specificity in P. aeruginosa; 100% sensitivity and specificity in Acinetobacter) compared to other screening methods used in this study. This study provided useful informationon the local prevalence of MBL-producing P. aeruginosa and Acinetobacter in our hospital.
Disc potentiation test with CAZ/2-MPA disc appears to be reliable and convenient MBL detection method in the routine clinical laboratory.
5.A preliminary screening of potentially antimalarial plants against Plasmodium falciparum in vitro
Khaw, L.T. ; Leerach ; N., Yap ; N.J. ; Jaturas ; N. ; Mahboob T. ; Tan, T.C. ; Lim, Y.A.L.
Tropical Biomedicine 2015;32(4):676-683
Plasmodium is a blood protozoan parasite that is responsible for malaria. To date,
Plasmodium falciparum has shown multi-drug resistance, particularly in Thailand, Myanmar
and Malaysia. The aim of the study is to screen the plant extracts that can effectively inhibit
P. falciparum 3D7, a common lab strain malaria parasite. Nine plants were collected and
processed through maceration using hexane, chloroform and ethanol, resulting in 24 crude
plant extracts. Of these, extracts from Artabotrys crassifolius, Pericampylus glacus and
Leuconotis eugeniifolia showed promising antiplasmodial activities at IC50 of 15.32 to 39.75
μg/mL in a modified schizont maturation assay. Further studies are warranted to explore its
efficacies and lead compounds of these three plant extracts for the development of
antiplasmodial drugs.
6.Toxoplasmosis in HIV and non HIV prisoners in Malaysia
Angal, L., Lim, Y.A., Yap, N.J., Ngui, R., Amir, A., Rohela, M.
Tropical Biomedicine 2016;33(1):159-169
This is the first Malaysian study to determine the trend and risk factors of Toxoplasma
gondii infection in HIV and non-HIV among prisoners in terms of socio-demographic and
behavioural characteristics, clinical presentations and haematological distributions. Blood
samples from 303 participants, comprising 133 HIV positive and 170 HIV negative inmates
were collected in EDTA and plain tubes. Two mls of each blood sample in plain tubes were
centrifuged at 1500 rpm for 10 minutes and the sera obtained were subjected to ELISA for
detection of Toxoplasma IgM and IgG antibody towards Toxoplasma antigen. Seropositive
samples for Toxoplasma IgM or both Toxoplasma IgM and IgG were further tested with
Novalisa Toxoplasma gondii IgG avidity test to rule out acute from latent infections. Blood
in EDTA tubes were sent to Clinical Diagnostic Lab (CDL), University Malaya Medical Centre
(UMMC), Kuala Lumpur for complete blood count and differential count analysis. Overall
seroprevalence of anti-T. gondii antibodies was detected in 41.9% (127 out of 303) of the
participants. Anti-T. gondii antibodies was detected in 63.2% (84 out of 133) of HIV positive
subjects and in 25.3% (43 out of 170) of HIV negative subjects. Seroprevalence of anti-T.
gondii antibodies was significantly higher in HIV positive than in HIV negative subjects (OR
= 5.06; 95% CI = 3.09-8.30; p < 0.001). The rate of T. gondii seropositivity increased significantly
in those aged 40 years and above, HIV positive individuals and those with history of drug
abuse. White blood cells (WBCs), neutrophils and basophils counts decreased significantly in
those infected with Toxoplasma. Creating awareness about T. gondii infection and follow-up
of their status is recommended. Moreover, screening of T. gondii infection in HIV-infected
individuals should be considered for better treatment and management, including control and
prevention.
7.Physiological and epidemiological study of some parasitic and viral enteric infections in dromedary camels in Al-Muthanna province
Al-Yasari, A.M.R. ; Alsalih, N.J. ; Alsaadawi, M.A.
Tropical Biomedicine 2024;41(No.1):1-13
Understanding the normal physiology of the body is the key to study the changes that occur due to any
infection. It is known that enteric infections play a considerable role in affecting normal body status.
Thus, this study was designed for investigating the enteric infections in Arabian camels in Al-Muthanna
Province. In this investigation, 588 fecal and blood serum samples (for diarrheic camels only) were
collected from the camels in different areas of Al-Muthanna Province, Iraq from both sexes of different
ages during the period from October 2020 up to the end of August 2021. The samples were examined
using routine microscopic examination techniques, hematological techniques, and ELISA for parasitic
and viral identification. Eimeria rajasthani, Isospora orlovi were recorded for the first time in Iraqi
camels with clinical signs of diarrhea, dehydration, and emaciation. The study recorded four types of
protozoa: Eimeria spp., Isospora, Cryptosporidium and Balantidium coli. The recorded types of Eimeria
were E. dromedarii, E. cameli, and E. rajasthani. There was a significant effect of age on infection rates
with Eimeria spp. as the highest Eimeria ratio was in ages of less than two years animals. The infection
rates were also affected with months which reached the highest ratios of Eimeria in October while the
lowest ratio of Eimeria was recorded in July. BVDV infection rate was found in camels that suffered from
diarrhea. There is no significant effect of sex on the onset of the viral disease in camels. For hematological
parameters, there were significant differences in RBCs, WBCs, Hb, and PCV values in protozoal and BVDV
infections. In conclusion, different kinds of protozoal and viral infections were recorded. Some of the
recorded infections were associated with acute clinical signs and have zoonotic importance.
8.Hematological and histopathological changes of rat’s hearts experimentally infected with protoscoleces
Alsaadawi, M.A. ; Al-Safar, A.H. ; Al-Yasari, A.M. ; Hussein, H.M. ; Allawi, A.H. ; Alsalih, N.J. ; Kalef, D.A.
Tropical Biomedicine 2022;39(No.1):117-125
Hydatidosis; is a zoonotic disease caused by Echinococcus granulosus and characterized by
infiltration of inflammatory cells. This study was investigated the hematological and
histopathological changes in the hearts of rats injected with protoscoleces. Rats were injected
with protoscoleces collected from either liver of sheep, goats, and cows (from the abattoir of
Al-Muthanna province, south of Iraq) or isolated from infected humans from Al-Hussein
Teaching Hospital. Sheep protoscoleces showed a significant increase of lymphocytes that
refer to the induction of a high response of the immune system in rats. The numbers of WBC,
RBCs, and platelets were generally increased in rats injected with protoscoleces isolated
from sheep and goats. These changes could refer to the activation of defense mechanisms
against the hydatid injected materials. However, the levels of MCV, MCH, MCHC, MPV and
PDW were less than normal values. Heart sections of rats injected with protoscoleces isolated
from humans showed clear histological changes. While TSP, TGP and TCP exhibited variant
histopathological changes such as infiltration of inflammatory cells, pink glass appearance
and congestion of arteries. Thus, these alterations can be considered as additional evidence
of how the immune response reacts against the injected materials in the heart.
9.Imported case of Leishmania tropica cutaneous leishmaniasis in a 10-year-old child in Malaysia
Tan, T.K. ; Yap, N.J. ; Leong, K.F. ; Teh, C.S. ; Tay, S.T. ; Lim, Y.A.L.
Tropical Biomedicine 2022;39(No.1):86-88
The present paper reported a first imported case of cutaneous leishmaniasis in a 10-yearold child who returned from Saudi Arabia to Malaysia. Six weeks after his travel to Malaysia,
two erythematous dermal nodules were developed over his right cheek and chin. Occurrence
of intracellular amastigote of Leishmania was observed through examination of skin biopsy
with hematoxylin and eosin stain. Furthermore, molecular analysis of ribosomal internal
transcribed spacer 1 (ITS1) of Leishmania spp. confirmed the child was infected with Leishmania
tropica. The child was given oral fluconazole and he had a 80% recovery before he went back
to Saudi Arabia.
10.Genetic diversity of Merozoite Surface Protein-1 gene block 2 allelic types in Plasmodium falciparum isolates from Malaysia and Thailand
Goh, X.T. ; Chua, K.H. ; Vythilingam, I. ; Lee, P.C. ; Tan, T.C. ; Yap, N.J. ; Chai, H.C. ; Nissapatorn, V. ; Lim, Y.A.L
Tropical Biomedicine 2019;36(1):70-80
Malaria is the most common vector-borne parasitic disease in Malaysia and Thailand,
especially in Malayan Borneo and along the Thailand border areas, but little is known about
the genetic diversity of the parasite. Present study aims to investigate the genetic diversity
of Plasmodium falciparum isolates in these two countries and eventually contributes to
more effective malaria control strategies, particularly in vaccine and antimalarial treatment.
One hundred and seventy three P. falciparum isolates were collected from Malaysia (n = 67)
and Thailand (n = 106) and genotyped using nested PCR targeting the polymorphic region of
MSP-1, block 2. Sequence analysis was conducted to investigate the allele diversity of the
isolates. Three allelic families were identified in Malaysian and Thailand P. falciparum
isolates, MAD20, K1 and RO33. Sequence analysis revealed that there were 5 different
MAD20, 1 K1 and 2 different RO33 for Malaysian isolates. Thailand isolates exhibited greater
polymorphism because there were 13 different MAD20, 6 different K1 and 2 different RO33
identified in this study. Multiclonal infections were observed for the isolates in both countries,
however, low multiplicity of infection (MOI) was observed for Malaysian (1.1) and Thailand
(1.2) isolates. Phylogenetic analysis showed that P. falciparum isolates of Malaysia and
Thailand were clustered in the same group for all the allelic families. Population structure of
P. falciparum isolates in Malaysia and Thailand exhibit extensive genetic polymorphism but
showed high similarities as well as comparable MOI.