MyMedR

Displaying publications 1 - 20 of 44 in total

Abstract:

Sort:

Isolation and Identification of novel toxins from a new mosquitocidal isolate from Malaysia, Bacillus thuringiensis subsp. jegathesan

Kawalek MD, Benjamin S, Lee HL, Gill SS

Appl Environ Microbiol, 1995 Aug;61(8):2965-9.
PMID: 7487029

A new mosquitocidal Bacillus thuringiensis subsp., jegathesan, has recently been isolated from Malaysia. Parasporal crystal inclusions were purified from this strain and bioassayed against fourth-instar larvae of Culex quinquefasciatus, Aedes aegypti, Aedes togoi, Aedes albopictus, Anopheles maculatus, and Mansonia uniformis. The 50% lethal concentration of crystal inclusions for each species was 0.34, 8.08, 0.34, 17.59, 3.91, and 120 ng/ml, respectively. These values show that parasporal inclusions from this new subspecies have mosquitocidal toxicity comparable to that of inclusions isolated from B. thuringiensis subsp. israelensis. Solubilized and chymotrypsin-activated parasporal inclusions possessed low-level hemolytic activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the crystals were composed of polypeptides of 77, 74, 72, 68, 55, 38, 35, 27, and 23 kDa. Analysis by Western blotting (immunoblotting) with polyclonal antisera raised against toxins purified from B. thuringiensis subsp. israelensis reveals that proteins in parasporal inclusions of subsp. jegathesan are distinct, because little cross-reactivity was shown. Analysis of the plasmid content of B. thuringiensis subsp. jegathesan indicates that the genes for toxin production may be located on 105- to 120-kb plasmids. Cry- clones that have been cured of these plasmids are nontoxic. Southern blot analysis of plasmid and chromosomal DNA from subsp. jegathesan showed little or low homology to the genes coding for CryIVA, CryIVB, and CryIVD from B. thuringiensis subsp. israelensis.

Matched MeSH terms: Hemolysin Proteins
Genetic and biochemical characterization of field-evolved resistance to Bacillus thuringiensis toxin Cry1Ac in the diamondback moth, Plutella xylostella

Sayyed AH, Raymond B, Ibiza-Palacios MS, Escriche B, Wright DJ

Appl Environ Microbiol, 2004 Dec;70(12):7010-7.
PMID: 15574894

The long-term usefulness of Bacillus thuringiensis Cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. Managing the evolution of resistance to B. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. To date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to B. thuringiensis, highly resistant field populations being rare. However, the selection pressures on field and laboratory populations are very different and may produce resistance genes with distinct characteristics. In order to better understand the genetics, biochemical mechanisms, and ecology of field-evolved resistance, a diamondback moth (Plutella xylostella) field population (Karak) which had been exposed to intensive spraying with B. thuringiensis subsp. kurstaki was collected from Malaysia. We detected a very high level of resistance to Cry1Ac; high levels of resistance to B. thuringiensis subsp. kurstaki Cry1Aa, Cry1Ab, and Cry1Fa; and a moderate level of resistance to Cry1Ca. The toxicity of Cry1Ja to the Karak population was not significantly different from that to a standard laboratory population (LAB-UK). Notable features of the Karak population were that field-selected resistance to B. thuringiensis subsp. kurstaki did not decline at all in unselected populations over 11 generations in laboratory microcosm experiments and that resistance to Cry1Ac declined only threefold over the same period. This finding may be due to a lack of fitness costs expressed by resistance strains, since such costs can be environmentally dependent and may not occur under ordinary laboratory culture conditions. Alternatively, resistance in the Karak population may have been near fixation, leading to a very slow increase in heterozygosity. Reciprocal genetic crosses between Karak and LAB-UK populations indicated that resistance was autosomal and recessive. At the highest dose of Cry1Ac tested, resistance was completely recessive, while at the lowest dose, it was incompletely dominant. A direct test of monogenic inheritance based on a backcross of F1 progeny with the Karak population suggested that resistance to Cry1Ac was controlled by a single locus. Binding studies with 125I-labeled Cry1Ab and Cry1Ac revealed greatly reduced binding to brush border membrane vesicles prepared from this field population.

Matched MeSH terms: Hemolysin Proteins
Genetic and biochemical approach for characterization of resistance to Bacillus thuringiensis toxin Cry1Ac in a field population of the diamondback moth, Plutella xylostella

Sayyed AH, Haward R, Herrero S, Ferré J, Wright DJ

Appl Environ Microbiol, 2000 Apr;66(4):1509-16.
PMID: 10742234

Four subpopulations of a Plutella xylostella (L.) strain from Malaysia (F(4) to F(8)) were selected with Bacillus thuringiensis subsp. kurstaki HD-1, Bacillus thuringiensis subsp. aizawai, Cry1Ab, and Cry1Ac, respectively, while a fifth subpopulation was left as unselected (UNSEL-MEL). Bioassays at F(9) found that selection with Cry1Ac, Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai gave resistance ratios of >95, 10, 7, and 3, respectively, compared with UNSEL-MEL (>10,500, 500, >100, and 26, respectively, compared with a susceptible population, ROTH). Resistance to Cry1Ac, Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai in UNSEL-MEL declined significantly by F(9). The Cry1Ac-selected population showed very little cross-resistance to Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai (5-, 1-, and 4-fold compared with UNSEL-MEL), whereas the Cry1Ab-, B. thuringiensis subsp. kurstaki-, and B. thuringiensis subsp. aizawai-selected populations showed high cross-resistance to Cry1Ac (60-, 100-, and 70-fold). The Cry1Ac-selected population was reselected (F(9) to F(13)) to give a resistance ratio of >2,400 compared with UNSEL-MEL. Binding studies with (125)I-labeled Cry1Ab and Cry1Ac revealed complete lack of binding to brush border membrane vesicles prepared from Cry1Ac-selected larvae (F(15)). Binding was also reduced, although less drastically, in the revertant population, which indicates that a modification in the common binding site of these two toxins was involved in the resistance mechanism in the original population. Reciprocal genetic crosses between Cry1Ac-reselected and ROTH insects indicated that resistance was autosomal and showed incomplete dominance. At the highest dose of Cry1Ac tested, resistance was recessive while at the lowest dose it was almost completely dominant. The F(2) progeny from a backcross of F(1) progeny with ROTH was tested with a concentration of Cry1Ac which would kill 100% of ROTH moths. Eight of the 12 families tested had 60 to 90% mortality, which indicated that more than one allele on separate loci was responsible for resistance to Cry1Ac.

Matched MeSH terms: Hemolysin Proteins
Fulltext Antihaemolytic and snake venom neutralizing effect of some Indian medicinal plants

Kumarapppan C, Jaswanth A, Kumarasunderi K

Asian Pac J Trop Med, 2011 Sep;4(9):743-7.
PMID: 21967700 DOI: 10.1016/S1995-7645(11)60185-5

OBJECTIVE: To validate traditional claims of usefulness of the Indian plants in management of poisonous snakebite and evaluate the antivenom properties displayed by the alcoholic extracts of Andrographis paniculata (A. paniculata), Crateva magna (C. magna), Gloriosa superba (G. superba) and Hydrocotyle javanica (H. javanica).
METHODS: These plants were collected, identified and the extracts were prepared by using conventional Soxhlet ethanol extraction technique. The venom neutralization activity was accessed in mice (20-25g) and number of mortalities was observed against clinically important snake (Naja nigricollis) venom. Present study also deals with in vitro membrane stabilizing activity of these plants against hyposaline induced human red blood corpuscles (HRBC).
RESULTS: Extracts of H. javanica and G. superba gave 80 % and 90 % protection to mice treated with minimum lethal dose of venom (LD(99)). These two plants showed significant neutralization effect against the venoms of Naja nigricollis venom. H. javanica and G. superba (25-100 mg/mL) produced significant changes of membrane stabilization of human red blood cells (HRBC) exposed to hyposaline-induced haemolysis.
CONCLUSIONS: We conclude that probably due to presence of various phytochemicals plays an important role in the anti-venom potential of these Indian medicinal plants against Naja nigricollis venom. The above observations confirmed that A. paniculata, C. magna, G. superba and H. javanica plant extracts possess potent snake venom neutralizing capacity and could potentially be used as an adjuvants for antivenin therapy in case of snakebite envenomation, especially against the local effects of cobra venoms.

Matched MeSH terms: Hemolysin Proteins/antagonists & inhibitors*
Fulltext Characterization of Burkholderia pseudomallei protein BPSL1375 validates the Putative hemolytic activity of the COG3176 N-Acyltransferase family

Ahmad L, Hung TL, Mat Akhir NA, Mohamed R, Nathan S, Firdaus-Raih M

BMC Microbiol, 2015;15:270.
PMID: 26597807 DOI: 10.1186/s12866-015-0604-4

There are still numerous protein subfamilies within families and superfamilies that do not yet have conclusive empirical experimental evidence providing a specific function. These proteins persist in databases with the annotation of a specific 'putative' function made by association with discernible features in the protein sequence.

Matched MeSH terms: Hemolysin Proteins/genetics; Hemolysin Proteins/metabolism*; Hemolysin Proteins/pharmacology; Hemolysin Proteins/chemistry
Fulltext Prevalence, virulence and antifungal activity of C. albicans isolated from infected root canals

Abraham SB, Al Marzooq F, Himratul-Aznita WH, Ahmed HMA, Samaranayake LP

BMC Oral Health, 2020 12 01;20(1):347.
PMID: 33256696 DOI: 10.1186/s12903-020-01347-5

BACKGROUND: There is limited data on the prevalence of Candida species in infected root canal systems of human teeth. We attempted to investigate the prevalence, genotype, virulence and the antifungal susceptibility of Candida albicans isolated from infected root canals of patients with primary and post-treatment infections in a UAE population.
METHODS: Microbiological samples from 71 subjects with infected root canals were aseptically collected, and cultured on Sabouraud dextrose agar, and C. albicans was identified using multiplex polymerase chain reaction, and the isolates were further subtyped using ABC genotyping system. Their relative virulence was compared using further four archival samples of endodontic origin from another geographical region, and four more salivary isolates, as controls. The virulence attributes compared were biofilm formation, and production of phospholipase and haemolysin, and the susceptibility to nystatin, amphotericin B, ketoconazole, and fluoconazole was also tested.
RESULTS: 4 out of 71 samples (5.6%) yielded Candida species. On analysis of variance among the groups, the intracanal isolates, mainly Genotype A, possessed a high degree of phospholipase and haemolysin activity (p

Matched MeSH terms: Hemolysin Proteins
Phage displayed Bacillus thuringiensis Cry1Ba4 toxin is toxic to Plutella xylostella

Nathan S, Aziz DH, Mahadi NM

Curr Microbiol, 2006 Nov;53(5):412-5.
PMID: 17036210

We constructed recombinant phage particles displaying the Bacillus thuringiensis Cry1Ba4 active toxin using the pfUSE5 and pComb3X phagemid vectors. The recombinant phage particles were screened and evaluated for displayed biologically active Cry1Ba4 toxin against the target insect larvae. Concurrent expression of Cry1Ba4 protoxin was carried out using the pETBlue -2 plasmid expression vector in Escherichia coli Tuner (DE3)pLacI and the protoxin was successfully expressed at a size of 129 kDa. In the bioassay, 3.30 mg crude extract of Cry1Ba4 protoxin, 9.35 x 10(9) TU and 7.70 x 10(9) TU of induced recombinant phage particles carrying Cry1Ba4 active toxin displayed on pComb3X and pFUSE5, respectively, demonstrated mortality of greater than 85% against Plutella xylostella (third-instar) within 48 hours. Thus, we have successfully displayed the Cry1Ba4 activated toxin on the surface of a phage and demonstrated toxicity towards larvae.

Matched MeSH terms: Hemolysin Proteins/pharmacology*
Detection of virulence associated genes, haemolysin and protease amongst Vibrio cholerae isolated in Malaysia

Iyer L, Vadivelu J, Puthucheary SD

Epidemiol Infect, 2000 Aug;125(1):27-34.
PMID: 11057956

Eighty-four strains of Vibrio cholerae O1, O139 and non-O1/non-O139 from clinical and environmental sources were investigated for the presence of the toxin co-regulated pilus gene, tcpA, the virulence cassette genes ctxA, zot, ace and cep and also for their ability to elaborate haemolysin and protease. The ctxA and zot genes were detected using DNA-DNA hybridization while the ace, cep and tcpA genes were detected using PCR. Production of haemolysin and protease was detected using mammalian erythrocytes and an agar diffusion assay respectively. Analysis of their virulence profiles showed six different groups designated Type I to Type VI and the major distinguishing factor among these profiles was in the in vitro production of haemolysin and/or protease. Clinical O1, O139 and environmental O1 strains were similar with regard to presence of the virulence cassette genes. All environmental O1 strains with the exception of one were found to possess ctxA, zot and ace giving rise to the probability that these strains may actually be of clinical origin. One strain which had only cep but none of the toxin genes may be a true environmental isolate. The virulence cassette and colonization factor genes were absent in all non-O1/non-O139 environmental strains but production of both the haemolysin and protease was present, indicating that these may be putative virulence factors. These findings suggest that with regard to its pathogenic potential, only strains of the O1 and O139 serogroup that possess the tcpA gene which encodes the phage receptor, have the potential to acquire the CTX genetic element and become choleragenic.

Matched MeSH terms: Hemolysin Proteins/analysis; Hemolysin Proteins/biosynthesis*
Mosquitocidal activity of a native Bacillus thuringiensis isolate Bt ReX02 from Gunung Jerai Forest, Malaysia against Culex quinquefasciatus and Aedes albopictus

Lakxmy AP, Xavier R, Reenajosephine CM, Lee YW, Marimuthu K, Kathiresan S, et al.

Eur Rev Med Pharmacol Sci, 2011 Feb;15(2):149-55.
PMID: 21434481

To evaluate the mosquito larvicidal potential of the native Bacillus thuringiensis isolate BtReXO2, which was isolated from a tropical rain forest ecosystem in Malaysia. This study also aimed at determining the phenotypic and biochemical characteristics of the isolate.

Matched MeSH terms: Hemolysin Proteins/pharmacology*
Detection of Vibrio parahaemolyticus in cockle (Anadara granosa) by PCR

Bilung LM, Radu S, Bahaman AR, Rahim RA, Napis S, Ling MW, et al.

FEMS Microbiol Lett, 2005 Nov 1;252(1):85-8.
PMID: 16216442

This study aimed to determine the occurrence of Vibrio parahaemolyticus in cockles (Anadara granosa) at a harvesting area and to detect the presence of virulent strains carrying the thermostable direct hemolysin (tdh) and TDH-related hemolysin genes (trh) using PCR. Of 100 samples, 62 were positive for the presence of V. parahaemolyticus with an MPN (most probable number) value greater than 3.0 (>1100 MPN per g). The PCR analysis revealed 2 samples to be positive for the tdh gene and 11 to be positive for the trh gene. Hence, these results demonstrate the presence of pathogenic V. parahaemolyticus in cockles harvested in the study area and reveal the potential risk of illness associated with their consumption.

Matched MeSH terms: Hemolysin Proteins
Fulltext Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from retail shrimps in Malaysia

Letchumanan V, Yin WF, Lee LH, Chan KG

Front Microbiol, 2015;6:33.
PMID: 25688239 DOI: 10.3389/fmicb.2015.00033

Vibrio parahaemolyticus is a marine and estuarine bacterium that has been the leading cause of foodborne outbreaks which leads to a significant threat to human health worldwide. Consumption of seafood contaminated with V. parahaemolyticus causes acute gastroenteritis in individuals. The bacterium poses two main virulence factor including the thermostable direct hemolysin (tdh) which is a pore-forming protein that contributes to the invasiveness of the bacterium in humans and TDH-related hemolysin (trh), which plays a similar role as tdh in the disease pathogenesis. This study aimed to investigate the antimicrobial resistance V. parahaemolyticus strains in shrimps purchased from wetmarkets and supermarkets. The toxR-based PCR assay indicated that a total of 57.8% (185/320) isolates were positive for V. parahaemolyticus. Only 10% (19/185) toxR-positive isolate exhibit the trh gene and none of the isolates were tested positive for tdh. The MAR index was measured for 14 common antimicrobial agents. The results indicated 98% of the isolates were highly susceptible to imipenem, ampicillin sulbactam (96%), chloramphenicol (95%), trimethoprim-sulfamethoxazole (93%), gentamicin (85%), levofloxacin (83%), and tetracycline (82%). The chloramphenicol (catA2) and kanamycin (aphA-3) resistance genes were detected in the resistant V. parahaemolyticus isolates. Our results demonstrate that shrimps are contaminated with V. parahaemolyticus, some of which carry the trh-gene thus being potential to cause food borne illness. The occurrence of multidrug resistance strains in the environment could be an indication of excessive usage of antibiotics in agriculture and aquaculture fields.

Matched MeSH terms: Hemolysin Proteins
Fulltext Vibrio parahaemolyticus: a review on the pathogenesis, prevalence, and advance molecular identification techniques

Letchumanan V, Chan KG, Lee LH

Front Microbiol, 2014;5:705.
PMID: 25566219 DOI: 10.3389/fmicb.2014.00705

Vibrio parahaemolyticus is a Gram-negative halophilic bacterium that is found in estuarine, marine and coastal environments. V. parahaemolyticus is the leading causal agent of human acute gastroenteritis following the consumption of raw, undercooked, or mishandled marine products. In rare cases, V. parahaemolyticus causes wound infection, ear infection or septicaemia in individuals with pre-existing medical conditions. V. parahaemolyticus has two hemolysins virulence factors that are thermostable direct hemolysin (tdh)-a pore-forming protein that contributes to the invasiveness of the bacterium in humans, and TDH-related hemolysin (trh), which plays a similar role as tdh in the disease pathogenesis. In addition, the bacterium is also encodes for adhesions and type III secretion systems (T3SS1 and T3SS2) to ensure its survival in the environment. This review aims at discussing the V. parahaemolyticus growth and characteristics, pathogenesis, prevalence and advances in molecular identification techniques.

Matched MeSH terms: Hemolysin Proteins
Cloning and sequencing of three new putative toxin genes from Clostridium bifermentans CH18

Barloy F, Lecadet MM, Delécluse A

Gene, 1998 May 12;211(2):293-9.
PMID: 9602158

Three new open reading frames were found downstream from cbm71, a toxin gene from Clostridium bifermentans malaysia (Cbm) strain CH18. The first one (91bp downstream) called cbm72, is 1857bp long and encodes a 71727-Da protein (Cbm72) with a sequence similar to that of Bacillus thuringiensis delta-endotoxins. This protein shows no significant toxicity to mosquito larvae. The two others, cbm17.1 (462bp) and cbm17.2 (459bp), are copies of the same gene encoding Cbm P18 and P16 polypeptides and located 426bp and 1022bp downstream from cbm72, respectively. They encode 17189-Da and 17451-Da proteins with sequences 44.6% similar to that of Aspergillus fumigatus hemolysin; however, they were not hemolytic in the conditions tested.

Matched MeSH terms: Hemolysin Proteins
Fulltext Molecular characterisation of Vibrio parahaemolyticus carrying tdh and trh genes using ERIC-, RAPD- and BOX-PCR on local Malaysia bloody clam and Lala

Yoke-Kqueen, C., Teck-Ee, K., Son, R, Yoshitsugu, N., Mitsuaki, N.

International Food Research Journal, 2013;20(6):3299-3305.
MyJurnal

Molecular typing methods have been widely applied for many purposes. In this study, such methods were adopted as DNA fingerprinting tools to determine the origin and divergence of virulent Vibrio parahaemolyticus strains found in local seafood. Although not all strain carry virulent tdh and trh gene, increasing prevalence demands an effective fingerprinting scheme which can constantly monitor and trace the sources of such emerging food pathogens. By using ERIC-, RAPD-, and BOX-PCR methods, 33 Vibrio parahaemolyticus isolates from local Malaysia bloody clam (Anadara granosa) and Lala (Orbicularia orbiculata) with confirmed presence of tdh and trh gene were characterised, followed by determination of clonal relatedness among virulent strains using cluster analysis and discriminatory index. This study also involved application of Immunomagnetic Separation (IMS) Method which significantly improved the specificity of strain isolation. Cluster analysis using Unweighted Pair Group Mathematical Averaging (UPGMA) and Dice Coefficient shown clustering according to isolation food source, IMS level and haemolysin gene possessed. Nevertheless, different DNA fingerprinting methods generated different clustering at different similarity cut-off percentage, regardless as individual or as composite dendrograms. ERIC- and RAPD-PCR composite fingerprinting relatively shown the highest discriminatory index at following similarity cutoff percentage: 0.68 at 50%; 0.83 at 65%; and 0.93 at 75%. Discriminatory power increased with similarity cut-off percentage. However, result also suggested that BOX-PCR might be an effective fingerprinting tool, as it generated three clusters with no single-colony isolate at 70% similarity cut-off. This study not only achieved its objective to determine clonal relatedness among virulent strains from local seafood via characterisation, but also speculated the best possible combination of molecular typing methods to effectively do so.

Matched MeSH terms: Hemolysin Proteins
Fulltext Detection of aerolysin and hemolysin genes in Aeromonas spp. isolated from environmental and shellfish sources by polymerase chain reaction

Yousr, A.H., Nipis, S., Rusul, G.R.A., Son, R.

International Food Research Journal, 2007;14(2):115-122.
MyJurnal

Polymerase chain reaction (PCR) technique was used to assay for the detection of specific genes in the genomes of the Aeromonas spp. isolated from environmental and shellfish sources, particularly aero and hlyA genes, responsible for aerolysin and hemolysin toxins production in this genus. The results showed that: (i) the 1500 bp amplicon of the hlyA gene was detected in 20/38 of the Aeromonas hydrophila, 13/38 of the A. caviae and 6/9 of the A. veronii biovar sobria isolates; (ii) the 690 bp amplicon of the aero gene was detected in 20/38 of A. hydrophila, 17/38 of A. caviae and 6/9 of A. veronii biovar sobria isolates; (iii) the nucleotide blast results of aerolysin gene sequences of the representative strains of A. hydrophila, A. caviae and A. veronii biovar sobria revealed a high homology of 94%, 95% and 95% with published sequences, respectively and ; (iv) the protein blast showed 97%, 94% and 96% homology when compared to the published sequences, respectively. The finding of A. hydrophila virulence genes in other members of the genus Aeromonas, may give a new perspective to the significance of these results. The method described here may be a useful detection tool to assist in further investigation of aero and hlyA genes in the genus Aeromonas, especially for food microbiologist.

Matched MeSH terms: Hemolysin Proteins
Rapid detection and enumeration of pathogenic Vibrio parahaemolyticus in raw vegetables from retail outlets

International Food Research Journal, 2011;18(1):67-78.
MyJurnal

This study aims to determine the frequency and density of potentially pathogenic Vibrio parahaemolyticus, defined as those possessing thermostable-direct hemolysin (tdh) and/or tdh-related hemolysin (trh) genes, in raw salad vegetables at retail level in Selangor, Malaysia. A combination of Most Probable Number - Polymerase Chain Reaction (MPN-PCR) method was applied to detect the presence of tdh and/or trh gene-possessing V. parahaemolyticus and to enumerate their density in the samples. A total of 276 samples of vegetables commonly eaten raw in Malaysia (Cabbage = 30; Carrot = 31; Cucumber = 28; Four winged bean = 26; Indian pennywort = 17; Japanese parsley = 21; Lettuce = 16; Long bean = 32; Sweet potato = 29; Tomato = 38; Wild cosmos = 8) were analyzed. The samples were purchased from two supermarkets (A and B) and two wet markets (C and D). With the MPN-PCR technique, about 12.0% of the samples were positive for the presence of V. parahaemolyticus tdh-positive, with maximum densities of up to 39 MPN/g. The total frequency of V. parahaemolyticus trh-positive in the samples was 10.1%, with maximum concentration 15 MPN/g. V. parahaemolyticus tdh-positive was most prevalent in samples from Wet Market C (20.78%) and also in vegetable type Oenanthe stolonifera (Japanese parsley) with 19.0%, while V. parahaemolyticus trhpositive was predominant in samples from Wet Market D (16.7%) and was most frequent in both Oenanthe stolonifera (Japanese parsley) and Cucumis sativus (Cucumber) with 14.3% prevalence for each type. The results highlighted the fact that raw vegetables could be contaminated with virulent V. parahaemolyticus and could act as a transmission route, thus poses risk to consumers from the consumption of raw vegetables. To the author’s knowledge, this is the first assessment of V. parahaemolyticus carrying tdh and trh genes in raw
vegetables from retail outlets in Malaysia.

Matched MeSH terms: Hemolysin Proteins
Fulltext Detection and antibiotic susceptibility profiles of Listeria monocytogenes in wildlife and water samples in Kubah National Park, Sarawak, Malaysia

Lesley, M.B., Velnetti, L., Fazira, A.A., Kasing, A., Samuel, L., Micky, V., et al.

International Food Research Journal, 2016;23(1):360-365.
MyJurnal

This study was conducted to detect the presence of Listeria monocytogenes (L. monocytogenes)
and screen for its antibiotic susceptibility characteristic from wildlife and water samples at
Kubah National Park, Sarawak, Malaysia. Samples collected were incubated and streaked on
selective medium PALCAM agar to confirm the presence of Listeria spp. before they were
further tested using molecular analysis. Specific Polymerase Chain Reaction (PCR) assay were
performed to target specific virulence gene, haemolysin gene, hlyA to further distinguish the
presence of this pathogenic bacteria in the samples. Overall, out of the 30 samples tested, 10
samples were confirmed as to contain L. monocytogenes strains and selected to subsequent
antibiotic susceptibility test. Susceptibility patterns to 10 antibiotics were investigated
among the L. monocytogenes strains. All strains were uniformly resistant to tetracycline and
erythromycin. On the other hand, all strains were sensitive to gentamycin and tobramycin. The
multiple antibiotic resistance shown by the strains in this study indicate the potential health
hazard associated with the possible transmission between wildlife and water to its surrounding
environment especially visitors and workers of Kubah National Park, Sarawak, Malaysia.

Matched MeSH terms: Hemolysin Proteins
Fulltext Genome-based proteomic analysis of Lignosus rhinocerotis (Cooke) Ryvarden sclerotium

Yap HY, Fung SY, Ng ST, Tan CS, Tan NH

Int J Med Sci, 2015;12(1):23-31.
PMID: 25552915 DOI: 10.7150/ijms.10019

Lignosus rhinocerotis (Cooke) Ryvarden (Polyporales, Basidiomycota), also known as the tiger milk mushroom, has received much interest in recent years owing to its wide-range ethnobotanical uses and the recent success in its domestication. The sclerotium is the part with medicinal value. Using two-dimensional gel electrophoresis coupled with mass spectrometry analysis, a total of 16 non-redundant, major proteins were identified with high confidence level in L. rhinocerotis sclerotium based on its genome as custom mapping database. Some of these proteins, such as the putative lectins, immunomodulatory proteins, superoxide dismutase, and aegerolysin may have pharmaceutical potential; while others are involved in nutrient mobilization and the protective antioxidant mechanism in the sclerotium. The findings from this study provide a molecular basis for future research on potential pharmacologically active proteins of L. rhinocerotis.

Matched MeSH terms: Hemolysin Proteins/pharmacology
Fulltext Survival study and haemolysin activity of Escherichia coli in raw and pasteurized milk produced in Negeri Sembilan

Farra Amira Mohamed, Aimi Nadia Ramli,, Noorlis Ahmad

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(1):66-77.
MyJurnal

Demand for milk has increased in Malaysia due to the increased in awareness of healthy foods consumption.
Hence, research of milk is crucial to ensure that it is not contaminated with Escherichia coli. This study
evaluated the survival of Escherichia coli at different temperature and haemolysin activity of Escherichia
coli on blood agar. A total of 8 samples of raw fresh and pasteurized milk were collected from nearby farm
and market in Negeri Sembilan, Malaysia. After an overnight exposure to four different temperatures of
0
0C, 280C, 350C and 450C, the bacteriological test of milk was evaluated for the presence of Escherichia
coli. Overall, all raw fresh milk sampled exceeded the acceptable limit of bacterial count of 1 x 105 CFU/ml.
Raw fresh milk recorded the highest count at 35oC with 4.4 x 107 CFU/ml and the lowest at 0oC with 8.3 x
104 CFU/ml. The presence of Escherichia coli was detected in 7/20(35%) of the total raw fresh milk
samples. All pasteurized milk showed no presence of Escherichia coli due to the effectiveness of heat
treatment. Haemolysin test showed no haemolytic activity. Milk contaminated with Escherichia coli can
cause diarrheal, gastrointestinal diseases and urinary infection. Hence, it is important to study the survival
rate of Escherichia coli and its pathogenicity in milk to ensure public safety.

Matched MeSH terms: Hemolysin Proteins
Cloning and expression of the first anaerobic toxin gene from Clostridium bifermentans subsp. malaysia, encoding a new mosquitocidal protein with homologies to Bacillus thuringiensis delta-endotoxins

Barloy F, Delécluse A, Nicolas L, Lecadet MM

J Bacteriol, 1996 Jun;178(11):3099-105.
PMID: 8655486

A gene (cbm71) encoding a 71,128-Da mosquitocidal protein (Cbm71) was obtained by screening a size-fractionated XbaI digest of total genomic DNA from Clostridium bifermentans subsp. malaysia CH18 with two gene-specific oligonucleotide probes. The sequence of the Cbm71 protein, as deduced from the sequence of cbm71, corresponds to that of the 66-kDa protein previously described as one of the mosquitocidal components of C. bifermentans subsp. malaysia. Cbm71 shows limited similarities with Bacillus thuringiensis delta-endotoxins, especially in the four first conserved blocks. However, Cbm71 was not immunologically related to any of the Cry toxins and thus belongs to a novel class of mosquitocidal protein. The cbm71 gene was expressed in a nontoxic strain of B. thuringiensis, and Cbm71 was produced during sporulation and secreted to the supernatant of culture. Trichloroacetic-precipitated supernatant preparations were toxic for mosquito larvae of the species Aedes aegypti, Culex pipiens, and Anopheles stephensi.

Matched MeSH terms: Hemolysin Proteins

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links