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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
Genetics of spinosad resistance in a multi-resistant field-selected population of Plutella xylostella

Sayyed AH, Omar D, Wright DJ

Pest Manag Sci, 2004 Aug;60(8):827-32.
PMID: 15307676

Resistance to the bacteria-derived insecticides spinosad (Conserve), abamectin (Vertimec), Bacillus thuringiensis var kurstaki (Btk) (Dipel), B thuringiensis var aizawai (Bta) (Xentari), B thuringiensis crystal endotoxins Cry1Ac and Cry1Ca, and to the synthetic insecticide fipronil was estimated in a freshly-collected field population (CH1 strain) of Plutella xylostella (L) from the Cameron Highlands, Malaysia. Laboratory bioassays at G1 indicated significant levels of resistance to spinosad, abamectin, Cry1Ac, Btk, Cry1Ca, fipronil and Bta when compared with a laboratory insecticide-susceptible population. Logit regression analysis of F1 reciprocal crosses indicated that resistance to spinosad in the CH1 population was inherited as a co-dominant trait. At the highest dose of spinosad tested, resistance was close to completely recessive, while at the lowest dose it was incompletely dominant. A direct test of monogenic inheritance based on a back-cross of F1 progeny with CH1 suggested that resistance to spinosad was controlled by a single locus.

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
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
Cross-resistance and inheritance of resistance to Bacillus thuringiensis toxin Cry1Ac in diamondback moth (Plutella xylostella L) from lowland Malaysia

Sayyed AH, Wright DJ

Pest Manag Sci, 2001 May;57(5):413-21.
PMID: 11374157

A field population of Plutella xylostella from Malaysia (SERD4) was divided into five sub-populations and four were selected (G2-G5) with the Bacillus thuringiensis insecticidal crystal (Cry) toxins Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da. Bioassay at G6 gave resistance ratios of 88, 5, 2 and 3 for Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da respectively compared with the unselected sub-population (UNSEL-SERD4). The Cry1Ac-selected population showed little cross-resistance to Cry1Ab, Cry1Ca and Cry1Da, (3-, 2- and 3-fold compared with UNSEL-SERD4), whereas the Cry1Ab-SEL sub-population showed marked cross-resistance to Cry1Ac (40-fold), much greater than Cry1Ab itself. In contrast, the Cry1Ca- and Cry1Da-SEL sub-population showed little if any cross-resistance to Cry1Ac and Cry1Ab. The mode of inheritance of resistance to Cry1Ac was examined in Cry1Ac-selected SERD4 by standard reciprocal crosses and back-crosses using a laboratory insecticide-susceptible population (ROTH). Logit regression analysis of F1 reciprocal crosses indicated that resistance to Cry1Ac was inherited as an incompletely dominant trait. At the highest dose of Cry1Ac tested, resistance was recessive, while at the lowest dose it was almost completely dominant. The F2 progeny from a back-cross of F1 progeny with ROTH were tested with a concentration of Cry1Ac that would kill 100% of ROTH. The mortality ranged between 50 and 95% in seven families of back-cross progeny, which indicated that more than one allele on separate loci were responsible for resistance to Cry1Ac.

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
Application of streptavidin mass spectrometric immunoassay tips for immunoaffinity based antibody phage display panning

Chin CF, Ler LW, Choong YS, Ong EB, Ismail A, Tye GJ, et al.

J Microbiol Methods, 2016 Jan;120:6-14.
PMID: 26581498 DOI: 10.1016/j.mimet.2015.11.007

Antibody phage display panning involves the enrichment of antibodies against specific targets by affinity. In recent years, several new methods for panning have been introduced to accommodate the growing application of antibody phage display. The present work is concerned with the application of streptavidin mass spectrometry immunoassay (MSIA™) Disposable Automation Research Tips (D.A.R.T's®) for antibody phage display. The system was initially designed to isolate antigens by affinity selection for mass spectrometry analysis. The streptavidin MSIA™ D.A.R.T's® system allows for easy attachment of biotinylated target antigens on the solid surface for presentation to the phage library. As proof-of-concept, a domain antibody library was passed through the tips attached with the Hemolysin E antigen. After binding and washing, the bound phages were eluted via standard acid dissociation and the phages were rescued for subsequent panning rounds. Polyclonal enrichment was observed for three rounds of panning with five monoclonal domain antibodies identified. The proposed method allows for a convenient, rapid and semi-automated alternative to conventional antibody panning strategies.

Matched MeSH terms: 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
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
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
Fipronil resistance in the diamondback moth (Lepidoptera: Plutellidae): inheritance and number of genes involved

Sayyed AH, Wright DJ

J Econ Entomol, 2004 Dec;97(6):2043-50.
PMID: 15666763

Bioassays (at generation 1, G1) using fipronil, spinosad, indoxacarb, and Bacillus thuringiensis toxins Cry1Ac and Cry1Ca with a newly collected field population of Plutella xylostella (L.) from farmers fields in the Cameron Highlands, Malaysia, indicated a resistance ratio of approximately 400-, 1,170-, 330-, 2,840-, and 1,410-fold, respectively, compared with a laboratory-susceptible population of P. xylostella (ROTH). At G3, the field-derived population was divided into two subpopulations, one was selected (G3 to G7) with fipronil (fip-SEL), whereas the second was left unselected (UNSEL). Bioassays at G8 found that selection with fipronil gave a resistance ratio of approximately 490 compared with UNSEL and approximately 770 compared with ROTH. The resistance ratio for fipronil, spinosad, indoxacarb, Cry1Ac, and Cry1Ca in the UNSEL population declined significantly by G8. Logit regression analysis of F1 reciprocal crosses between fip-SEL (at G8) and UNSEL indicated that resistance to fipronil in the fip-SEL population was inherited as an autosomal, incompletely recessive (D(LC) = 0.37) trait. At the highest dose of fipronil tested, resistance was completely recessive, whereas at the lowest dose it was incompletely recessive. A direct test of monogenic inheritance based on a backcross of F1 progeny with fip-SEL suggested that resistance to fipronil was controlled by a single locus. The fip-SEL population at G8 showed little change in its response to spinosad and indoxacarb compared with G1, whereas its susceptibility to Cry1Ac and Cry1Ca increased markedly over the selection period. This suggests that there may be some low level of cross-resistance between fipronil, spinosad, and indoxacarb.

Matched MeSH terms: Hemolysin Proteins
Fulltext Suppression of Staphylococcus aureus biofilm formation and virulence by a benzimidazole derivative, UM-C162

Kong C, Chee CF, Richter K, Thomas N, Abd Rahman N, Nathan S

Sci Rep, 2018 02 09;8(1):2758.
PMID: 29426873 DOI: 10.1038/s41598-018-21141-2

Staphylococcus aureus is a major cause of nosocomial infections and secretes a diverse spectrum of virulence determinants as well as forms biofilm. The emergence of antibiotic-resistant S. aureus highlights the need for alternative forms of therapeutics other than conventional antibiotics. One route to meet this need is screening small molecule derivatives for potential anti-infective activity. Using a previously optimized C. elegans - S. aureus small molecule screen, we identified a benzimidazole derivative, UM-C162, which rescued nematodes from a S. aureus infection. UM-C162 prevented the formation of biofilm in a dose-dependent manner without interfering with bacterial viability. To examine the effect of UM-C162 on the expression of S. aureus virulence genes, a genome-wide transcriptome analysis was performed on UM-C162-treated pathogen. Our data indicated that the genes associated with biofilm formation, particularly those involved in bacterial attachment, were suppressed in UM-C162-treated bacteria. Additionally, a set of genes encoding vital S. aureus virulence factors were also down-regulated in the presence of UM-C162. Further biochemical analysis validated that UM-C162-mediated disruption of S. aureus hemolysins, proteases and clumping factors production. Collectively, our findings propose that UM-C162 is a promising compound that can be further developed as an anti-virulence agent to control S. aureus infections.

Matched MeSH terms: Hemolysin Proteins
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
Cross-resistance between a Bacillus thuringiensis Cry toxin and non-Bt insecticides in the diamondback moth

Sayyed AH, Moores G, Crickmore N, Wright DJ

Pest Manag Sci, 2008 Aug;64(8):813-9.
PMID: 18383197 DOI: 10.1002/ps.1570

Bacillus thuringiensis Berliner (Bt) crystal (Cry) toxins are expressed in various transgenic crops and are also used as sprays in integrated pest management and organic agricultural systems. The diamondback moth (Plutella xylostella L.) is a major worldwide pest of crucifer crops and one that has readily acquired field resistance to a broad range of insecticides.

Matched MeSH terms: Hemolysin Proteins/pharmacology*
Fulltext Evaluation of PAIusp subtyping to characterize uropathogenic E. coli isolates

Lai YM, Zaw MT, Shamsudin SB, Lin Z

J Infect Dev Ctries, 2016 Oct 31;10(10):1053-1058.
PMID: 27801366 DOI: 10.3855/jidc.6944

INTRODUCTION: Uropathogenic virulence factors have been identified by comparing the prevalence of these among urinary tract isolates and environmental strains. The uropathogenic-specific protein (USP) gene is present on the pathogenicity island (PAI) of uropathogenic Escherichia coli (UPEC) and, depending on its two diverse gene types and the sequential patterns of three open reading frame units (orfUs) following it, there is a method to characterize UPEC epidemiologically called PAIusp subtyping.
METHODOLOGY: A total of 162 UPEC isolates from Sabah, Malaysia, were tested for the presence of the usp gene and the sequential patterns of three orfUs following it using polymerase chain reaction (PCR). In addition, by means of triplex PCR, the prevalence of the usp gene was compared with other two VFs of UPEC, namely alpha hemolysin (α-hly) and cytotoxic necrotizing factor (cnf-1) genes encoding two toxins.
RESULTS: The results showed that the usp gene was found in 78.40% of UPEC isolates, indicating that its prevalence was comparable to that found in a previous study in Japan. The two or three orfUs were also associated with the usp gene in this study. All the PAIusp subtypes observed in Japan were present in this study, while subtype IIa was the most common in both studies. The usp gene was observed in a higher percentage of isolates when compared with α-hly and cnf-1 genes.
CONCLUSIONS: The findings in Japan and Sabah, East Malaysia, were similar, indicating that PAIusp subtyping is applicable to the characterization of UPEC strains epidemiologically elsewhere in the world.

Matched MeSH terms: Hemolysin Proteins/genetics
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 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*
Enhanced secretory production of hemolysin-mediated cyclodextrin glucanotransferase in Escherichia coli by random mutagenesis of the ABC transporter system

Low KO, Mahadi NM, Abdul Rahim R, Rabu A, Abu Bakar FD, Abdul Murad AM, et al.

J Biotechnol, 2010 Dec;150(4):453-9.
PMID: 20959127 DOI: 10.1016/j.jbiotec.2010.10.001

The hemolysin transport system was found to mediate the release of cyclodextrin glucanotransferase (CGTase) into the extracellular medium when it was fused to the C-terminal 61 amino acids of HlyA (HlyAs(61)). To produce an improved-secretion variant, the hly components (hlyAs, hlyB and hlyD) were engineered by directed evolution using error-prone PCR. Hly mutants were screened on solid LB-starch plate for halo zone larger than the parent strain. Through screening of about 1 × 10(4) Escherichia coli BL21(DE3) transformants, we succeeded in isolating five mutants that showed a 35-217% increase in the secretion level of CGTase-HlyAs(61) relative to the wild-type strain. The mutation sites of each mutant were located at HlyB, primarily along the transmembrane domain, implying that the corresponding region was important for the improved secretion of the target protein. In this study we describe the finding of novel site(s) of HlyB responsible for enhancing secretion of CGTase in E. coli.

Matched MeSH terms: Hemolysin Proteins/metabolism*
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

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