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Survival of Epidemic, Clinical, Faecal and Recreational Beach Enterococci Strains with Putative Virulence Genes in Marine and Fresh Waters  [PDF]
Asmat Ahmad, Ayokunle Christopher Dada, Gires Usup
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.56051

Culturable faecal coliform, epidemic, clinical, faecal and recreational beach enterococci strains possessing putative virulence genes were enumerated over the course of 5 weeks to comparatively assess their persistence in tropical marine and fresh waters. For the clinical and epidemic strains tested, it took 2.38 ± 0.45 days for a 1-log reduction (T90) in marine water. A higher T90 average of 2.51 ± 0.08 was observed for the commensal and environmental strains. Generally, lower T90 values of 2.14 ± 0.26 and 2.15 ± 0.16 days respectively were observed for hospital and community acquired enterococci strains in fresh water mesocosms subjected to tropical ambient temperature. Beach water enterococci and enterococci recovered from faeces of humans survived for up to 20 days and 23 days respectively in fresh and marine waters. The epidemic strain, MMH594, an esp-positive clinical bacteremia isolate that previously caused multiple infections in a hospital ward outbreak fares favourably well in tropical marine and fresh aquatic environments. For enterococci, the decay rate was approximately 13% higher in fresh water than was observed for marine water. On the contrary, for E. coli, the decay rate was approximately 17% lower in fresh water than was observed in marine water. Generally, the whole, the population trends of E. coli and enterococci in fresh and marine water mesocosms did not reveal any evidence of growth. Our findings suggest that potentially pathogenic bacteria can resume active growth after three weeks of being harboured by the reservoir-beach sand and still pose threat to public health.

Heavy-Metal Tolerance and Antibiotic Susceptibility of Red Pigmented Bacteria Isolated from Marine Environment  [PDF]
Mahtab Jafarzade, Suhaiza Mohamad, Gires Usup, Asmat Ahmad
Natural Resources (NR) , 2012, DOI: 10.4236/nr.2012.34022
Abstract: This study was undertaken to determine heavy metal resistance and antibiotic susceptibility of three non-pathogenic red pigmented bacteria namely WPRA3, SM11-3j and SC-G18, isolated from marine environments of Malaysia. The bacteria isolates were identified by 16S rRNA sequencing and by biochemical and morphological tests. The 16S rRNA gene sequences of all isolates showed ≥96% similarity to Serratia spp. Antibiotic susceptibility test of isolates was assayed according to the Kirby-Bauer disc diffusion method. All isolates were highly resistant to beta-lactam antibiotics, but were susceptible to quinolone antibiotics. Minimum inhibitory concentration (MIC) of nine heavy metals (Ni2+, Co2+, Cr3+, Zn2+, Mn2+, Pb2+, Hg2+, Cd2+ and Cu2+) against the bacteria isolates were determined via the plate-dilution method. The isolates exhibited resistance to Ni2+, Co2+, Cr3+ and Zn2+. Isolates WPRA3 and SM11-3j showed higher multiple tolerances to heavy metals. The results obtained indicate that bacteria from marine environments of Malaysia present interesting metabolic activities, which should be studied and explored for potential biotechnological applications.
Olumide Adedokun Odeyemi,Ahmad Asmat,Gires Usup
Journal of Microbiology, Biotechnology and Food Sciences , 2012,
Abstract: This study aim to investigate antibiotics resistance profile and putative virulence factors of Aeromonas hydrophila isolated from estuary. Bacteria used for this study were isolated from water and sediment samples obtained from Sungai Melayu, Johor, Malaysia. Serially diluted 100 μL water and 1g sediment were inoculated on modified Rimler - Shott (mRS) agar. Colonies with distinct cultural characteristics were picked for further studies. Isolates were tested for biofilm productions, protease enzyme and antibiotics resistance profile using agar well diffusion method against 10 commercial antibiotics. Congo Red Agar (CRA), Microplate and Standard Tube (ST) methods were used for assessment of biofilm formation among the isolates while Skim Milk Agar was used for protease production. Sw.KMJ 3 and Sw.KMJ 9 produced black crystalline colonies on CRA. Six of the isolates were biofilm producers in ST method. Result of Microplate method, helped in grouping the isolates into weak (n = 8), moderate (n = 3) and strong producers (n = 4) at 540 nm wavelength. All the isolates were classified as weak ODc ODi 0.1, moderate ODi = 0.1 0.12 and strong producers ODi 0.12 respectively at 540 nm wavelength. Antibiotics susceptibility test also revealed that all the isolates were resistant to between 6 and 10 antibiotics. Two isolates each were resistant to 6 (60 %), 7 (70 %) and 9 (90 %) antibiotics respectively. Eight of the isolates showed resistance to 8 (80 %) antibiotics while only isolate Sw.KMJ-7 showed resistance to all the tested antibiotics. Sw.KMJ-3, Sw.KMJ-8 and Sw.KMJ-9 produced protease enzyme on SMA. The isolates were also found to be resistant to both antibiotics and heavy metals.
Bacteriological Monitoring and Sustainable Management of Beach Water Quality in Malaysia: Problems and Prospects
Ayokunle Christopher Dada,Ahmad Asmat,Usup Gires,Lee Yook Heng
Global Journal of Health Science , 2012, DOI: 10.5539/gjhs.v4n3p126
Abstract: Despite the growing demand of tourism in Malaysia, there are no resolute efforts to develop beaches as tourist destinations. With no incentives to monitor public beaches or to use them in a sustainable manner, they might eventually degenerate in quality as a result of influx of pollutants. This calls for concerted action plans with a view to promoting their sustainable use. The success of such plans is inevitably anchored on the availability of robust quality monitoring schemes. Although significant efforts have been channelled to collation and public disclosure of bacteriological quality data of rivers, beach water monitoring appears left out. This partly explains the dearth of published information related to beach water quality data. As part of an on-going nation-wide surveillance study on the bacteriological quality of recreational beaches, this paper draws on a situation analysis with a view to proffering recommendations that could be adapted for ensuring better beach water quality in Malaysia.
Toxicity of Puffer Fishes (Lagocephalus wheeleri Abe, Tabeta and Kitahama, 1984 and Lagocephalus sceleratus Gmelin, 1789) from the East Coast Waters of Peninsular Malaysia
K.D. Simon,A.G. Mazlan,Gires Usup
Journal of Biological Sciences , 2009,
Abstract: Toxicity analysis of the puffer fishes Lagocephalus wheeleri and Lagocephalus sceleratus from the East Coast Water of Peninsular Malaysia was carried out. The presence of tetrodotoxin (TTX) in fish tissue and cultures of bacteria isolated from the liver of the fish were determined. Detection of TTX was carried out by mouse bioassay, Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). The bacteria Shewanella sp. was isolated from the liver of L. wheeleri while, Exiguobacterium sp. and Staphylococcus sp. were isolated from the liver of L. sceleratus. Mouse bioassay showed that tissue extracts of L. wheeleri and culture supernatants of Shewanella sp. were positive for TTX. Tissue extracts of L. sceleratus and culture supernatants of Exiguobacterium sp. and Staphylococcus sp. exhibited non-lethal toxicity to mice but the symptoms were not typical of TTX poisoning. The symptoms in mice, coupled with TLC and HPLC analysis indicated that the toxic factor in L. wheeleri and Shewanella sp. was TTX. This study has confirmed the toxicity of the puffer L. wheeleri and some of this toxicity may be attributed to symbiotic bacteria.
CD44s and CD44v6 Expression in Head and Neck Epithelia
Brigitte Mack, Olivier Gires
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0003360
Abstract: Background CD44 splice variants are long-known as being associated with cell transformation. Recently, the standard form of CD44 (CD44s) was shown to be part of the signature of cancer stem cells (CSCs) in colon, breast, and in head and neck squamous cell carcinomas (HNSCC). This is somewhat in contradiction to previous reports on the expression of CD44s in HNSCC. The aim of the present study was to clarify the actual pattern of CD44 expression in head and neck epithelia. Methods Expression of CD44s and CD44v6 was analysed by immunohistochemistry with specific antibodies in primary head and neck tissues. Scoring of all specimens followed a two-parameters system, which implemented percentages of positive cells and staining intensities from ? to +++ (score = %×intensity; resulting max. score 300). In addition, cell surface expression of CD44s and CD44v6 was assessed in lymphocytes and HNSCC. Results In normal epithelia CD44s and CD44v6 were expressed in 60–95% and 50–80% of cells and yielded mean scores with a standard error of a mean (SEM) of 249.5±14.5 and 198±11.13, respectively. In oral leukoplakia and in moderately differentiated carcinomas CD44s and CD44v6 levels were slightly increased (278.9±7.16 and 242±11.7; 291.8±5.88 and 287.3±6.88). Carcinomas in situ displayed unchanged levels of both proteins whereas poorly differentiated carcinomas consistently expressed diminished CD44s and CD44v6 levels. Lymphocytes and HNSCC lines strongly expressed CD44s but not CD44v6. Conclusion CD44s and CD44v6 expression does not distinguish normal from benign or malignant epithelia of the head and neck. CD44s and CD44v6 were abundantly present in the great majority of cells in head and neck tissues, including carcinomas. Hence, the value of CD44s as a marker for the definition of a small subset of cells (i.e. less than 10%) representing head and neck cancer stem cells may need revision.
Shared sound changes in the Gorontalic language group; Implications for subgrouping
James Sneddon,Hunggu Tadjuddin Usup
Bijdragen tot de Taal-, Land- en Volkenkunde , 1986,
Keratin 8 expression in head and neck epithelia
Christoph Matthias, Brigitte Mack, Alexander Berghaus, Olivier Gires
BMC Cancer , 2008, DOI: 10.1186/1471-2407-8-267
Abstract: K8 expression was assessed upon immunohistochemistry with specific antibodies in cryosections of primary tumours of the head and neck area.K8 expression was characteristic of transformed tissue and marked early stages of disease, i.e. dysplastic oral leukoplakia, but not normal or hyperplastic epithelium. With the exception of carcinomas of the larynx and the tongue, K8 expression also strictly differentiated carcinomas from normal epithelium of the same origin. Furthermore, K8high was characteristic of cells, which had detached from the sites of primary tumours and had been invading the surrounding tissue at the time point of surgery.K8 is an excellent marker for head and neck malignancies, which allows for early detection as well as for visualisation of potentially disseminating tumour cells in vivo.Cytokeratin 8 (K8) is a structural protein, which forms intermediate filaments within the cytoplasm of simple epithelial cells [1] as a dimer with CK18 [2]. Along with other keratins, K8/CK18 generate a stabilizing framework, which is cell shape determining and allows cells to cope with mechanical stress. Cytokeratin filaments further on represent a mesh of "paths" on which signalling molecules, metabolites, and pathogens can travel the cell in an orientated fashion. The regulation of the localization of K8 within cells and polymerization into intermediate filaments is dependent upon its phosphorylation. Two main kinase families are instrumental in this context: the MAP kinase family member p38 [3] and PKC-ε related kinase [4]. Phosphorylation of K8 at serine in position 73 (Ser73) is mediated by p38 under stress such as orthovanadate treatment, and regulates keratin organization [5]. High p38 kinase activity correlated with the formation of keratin granules, while low p38 activity, ergo low K8 Ser73 phosphorylation, was associated with a prevented disassembly of the filament network [5]. As a potential counter-regulator and eventually in order to balance the phosphory
Performance Evaluation of a Small-Scale Turbojet Engine Running on Palm Oil Biodiesel Blends
A. R. Abu Talib,E. Gires,M. T. Ahmad
Journal of Fuels , 2014, DOI: 10.1155/2014/946485
Abstract: The experimental and simulated performance of an Armfield CM4 turbojet engine was investigated for palm oil methyl ester biodiesel (PME) and its blends with conventional Jet A-1 fuel. The volumetric blends of PME with Jet A-1 are 20, 50, 70, and 100% (B20, B50, B70, and B100). Fuel heating values (FHV) of each fuel mixture were obtained by calorimetric analysis. The experimental tests included performance tests for Jet A-1 and B20, while the performances of B50 to B100 were simulated using GasTurb 11 analytical software. In terms of maximum measured thrust, Jet A-1 yielded the highest value of 216?N, decreasing by 0.77%, 4%, 8%, and 12% with B20, B50, B70, and B100. It was found that B20 produced comparable results compared to the benchmark Jet A-1 tests, particularly with thrust and thermal efficiency. Slight performance penalties occurred due to the lower energy content of the biodiesel blends. The efficiency of the combustor improved with the addition of biodiesel while the other component efficiencies remained collectively consistent. This research shows that, at least for larger gas turbines, PME is suitable for use as an additive to Jet A-1 within 50% blends. 1. Introduction There is a general consensus within the literature that fossil fuel feedstock used for the production of aviation-grade kerosene fuel is dwindling. Koh and Ghazoul [1] expected a peak oil production scenario within the years 2010–2020, assuming that global oil consumption increases to 118 million barrels per day in 2030. Nygren et al. [2] projected that civil aviation traffic growth will increase at a rate of 5% per year, while fuel consumption will increase at 3% per year. Lee et al. [3] projected that aviation traffic growth will increase by 4.5% to 6% per year over the next twenty years, with traffic doubling every 15 years. This is further supported by the recent report by Deloitte [4], whereby passenger travel demand is expected to increase 5% over the next 20 years, contributing to increases in aircraft production. Despite the improvements in aircraft fuel efficiency since 1960 [5], further efforts need to be made in order to mitigate the dependency on traditional fuel sources and to replace current petrol-based fuels. Biodiesel is produced through the transesterification of pure vegetable or organic oils by replacing the triglyceride molecules with lighter alcohol molecules such as methanol or ethanol. The reaction is carried out with a strong base catalyst, producing glycerol in addition to transesterified vegetable oils (biodiesel) [6]. Canakci et al. [7] claimed that
Initial activation of EpCAM cleavage via cell-to-cell contact
Sabine Denzel, Dorothea Maetzel, Brigitte Mack, Carola Eggert, Gabriele B?rr, Olivier Gires
BMC Cancer , 2009, DOI: 10.1186/1471-2407-9-402
Abstract: EpCAM cleavage, induction of the target genes, and transmission of proliferation signals were investigated under varying density conditions using confocal laser scanning microscopy, immunoblotting, cell counting, and conditional cell systems.EpCAM cleavage, induction of the target genes, and transmission of proliferation signals were dependent on adequate cell-to-cell contact. If cell-to-cell contact was prohibited EpCAM did not provide growth advantages. If cells were allowed to undergo contact to each other, EpCAM transmitted proliferation signals based on signal transduction-related cleavage processes. Accordingly, the pre-cleaved version EpICD was not dependent on cell-to-cell contact in order to induce c-myc and cell proliferation, but necessitated nuclear translocation. For the case of contact-inhibited cells, although cleavage of EpCAM occurred, nuclear translocation of EpICD was reduced, as were EpCAM effects.Activation of EpCAM's cleavage and oncogenic capacity is dependent on cellular interaction (juxtacrine) to provide for initial signals of regulated intramembrane proteolysis, which then support signalling via soluble EpEX (paracrine).Epithelial cell adhesion molecule EpCAM is a membrane-bound glycoprotein involved in signalling that promotes gene transcription and cell proliferation [1-3]. The high-level over-expression of EpCAM in a plethora of carcinomas [4] led to the use of it as a marker with prognostic quality and as a target for therapeutic strategies [5-7]. Most-recent findings revealed the necessity for regulated intramembrane proteolysis (RIP) for the induction of EpCAM-related signal transduction, which initiates at the plasma membrane [8,9]. EpCAM becomes proteolytically activated via cleavage by TACE (tumour necrosis-factor α converting enzyme) and a gamma-secretase complex comprising presenilin 2 (PS2) [8]. After RIP, the intracellular domain of EpCAM (EpICD) is released in the cytoplasm and shuttles into the cell nucleus in a complex with
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