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1 – 10 of 243Hing Wah Lee, Ishak Abdul Azid and Kankanhally Narasimha Seetharamu
A simplified general purpose analytical finite element model has been developed to analyze the thermal performance of a continuous flow polymerase chain reaction (CPCR…
Abstract
A simplified general purpose analytical finite element model has been developed to analyze the thermal performance of a continuous flow polymerase chain reaction (CPCR) microdevice. The corresponding governing differential equations along with the appropriate boundary conditions have been solved using a self‐developed code in Matlab®. Results obtained from the finite element simulations have been validated with available published results and also showed good agreement with those obtained from commercial FEA package, ANSYS®. The present methodology has an added advantage due to its flexibility where the unit cell of the finite element model can be arranged into different orientation for analyses of different CPCR microdevice configuration. In microchannel heat sinks, the results obtained agree well with the published result which demonstrates the flexibility and robustness of present methodology to be used for various applications.
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Shaikha Khaled AL-Enezi, Nermin Kamal Saeed, Naeema A.A. Mahmood, Mohd Shadab, Ali Al Mahmeed and Mohammad Shahid
Bacterial vaginosis (BV) is quite common and linked with serious public health issues such as premature delivery and spread of sexually transmitted infections. The study aims to…
Abstract
Purpose
Bacterial vaginosis (BV) is quite common and linked with serious public health issues such as premature delivery and spread of sexually transmitted infections. The study aims to identify different genital mycoplasmas (GM) in high vaginal swabs (HVS) from adult females in Bahrain.
Design/methodology/approach
In total, 401 HVS were collected and cultured on MYCOFAST® RevolutioN 2 test for identification and antibiotic susceptibility. Polymerase chain reaction (PCR) was performed for detection of Mycoplasma genitalium (Mg), Mycoplasma hominis (Mh) and Ureaplasma species. DNA-probe based detection for Gardnerella, Candida and Trichomonas was performed by BD Affirm Assay. Representative PCR amplicons were sequenced by Sanger sequencing.
Findings
In PCR, Ureaplasma sp. was the most common GM, followed by Mg and Mh; the prevalence being 21.2, 5.2 and 1.5%, respectively. On the contrary, 10.7% samples showed positivity for Ureaplasma urealyticum (Uu) and 1.7% for Mh in MYCOFAST® RevolutioN 2. The concordance rates between MYCOFAST® RevolutioN 2 and PCR for Mh and Ureaplasma sp. were 97.7 and 84%, respectively. Considering PCR as gold standard, sensitivity, specificity, positive predictive value, and negative predictive value of MYCOFAST® RevolutioN 2 were 33.3, 98.8, 28.6, 98.9 and 37.7, 96.5, 74.4, 85.2% for Mh and Ureaplasma sp., respectively. The Uu and Mh isolates showed antibiotic-resistance ranging from 53%–58% and 71%–86%, respectively.
Research limitations/implications
The prevalence of Ureaplasma sp. was high. Significant co-occurrence of GM was noticed with BV. MYCOFAST® RevolutioN 2 had lower detection-rate than PCR, so a combination is suggested for wider diagnostic coverage.
Practical implications
The research reflects on status of prevalence of GM in adult females in Bahrain, and their co-occurrence with bacterial vaginosis. Diagnostic approach with combination of tests is suggested for wider coverage. The research has epidemiologic, diagnostic, and therapeutic implications.
Originality/value
This is the first report from the Kingdom of Bahrain reflecting on burden of GM from this geographic location. The diagnostic efficacy of MYCOFAST® RevolutionN 2 test and polymerase chain reaction was evaluated for GM detection.
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In order to maintain food safety standards, conventionalmicrobiological methods are still being used to detect bacteria andother organisms in food. However, these techniques are…
Abstract
In order to maintain food safety standards, conventional microbiological methods are still being used to detect bacteria and other organisms in food. However, these techniques are not ideal, as often it can be many days before results are known‐which may be of particular economic importance for those foods with a short shelf‐life. The introduction of newer technology, such as nucleic acid probe and related amplification technology in other fields, has transformed the detection of many organisms. The Polymerase Chain Reaction (PCR) allows nucleic acid probes, with their inherent specificity, to be used to detect organisms present in very low numbers within a short period of time. However, at present, in food microbiology, there are technical problems with using the PCR, as certain components in food interfere with the reaction. When these problems are resolved and with prospects for semi‐automation of the PCR technique, there should be enormous potential for the rapid detection of bacteria in foods, with consequent benefits to the food industry and to consumers.
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Minoo Moghimani, Afsaneh Salari, Mohammad Hashemi, Saman Soleimanpour, Golnaz Ranjbar and Asma Afshari
Kefir is a traditional fermented dairy beverage that has numerous health benefits due to the presence of bacteria and yeasts in an exopolysaccharide matrix. This study aims to…
Abstract
Purpose
Kefir is a traditional fermented dairy beverage that has numerous health benefits due to the presence of bacteria and yeasts in an exopolysaccharide matrix. This study aims to isolate and identify beneficial microorganisms and evaluate the antimicrobial activity of kefir beverage against two important food-borne pathogens including Salmonella Typhimurium and Listeria monocytogenes.
Design/methodology/approach
Microorganisms were identified by the polymerase chain reaction with specific primers, and antimicrobial activity was evaluated by the disk diffusion method.
Findings
The following microorganisms were identified as natural inhabitants of the kefir grains: Leuconostoc lactis, Lactococcus lactis subspecies lactis, Streptococcus cremoris, Enterococcus faecalis, Enterococcus faecium, Lactobacillus helveticus, Leuconostoc mesenteroides, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus casei, Bifidobacterium langum, Saccharomyces cerevisiae and Pichia fermentas. Also, the results obtained from the disk diffusion method showed the inhibitory effect of kefir milk on Salmonella Typhimurium and Listeria monocytogenes with an inhibitory average diameter of 8.3 ± 4–9.1 ± 2.8 and 3.4 ± 3–6.6 ± 3 mm, respectively.
Originality/value
The results of this study showed that Iranian traditional kefir beverage contained different species of lactic acid bacteria and yeasts and has antimicrobial activity against two important food-borne pathogens, Salmonella Typhimurium and Listeria monocytogenes, which the highest inhibitory effect was observed against Salmonella Typhimurium.
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C.G.J. Schabmueller, A.G.R. Evans, A. Brunnschweiler, G. Ensell, D.L. Leslie and M.A. Lee
Reports the design, fabrication and packaging of a micromachined silicon/Pyrex based chip for the polymerase chain reaction (PCR). The anodic bonding method is used for sealing…
Abstract
Reports the design, fabrication and packaging of a micromachined silicon/Pyrex based chip for the polymerase chain reaction (PCR). The anodic bonding method is used for sealing the chambers of 1μl volume with a Pyrex glass wafer. Platinum resistors on the back of the wafer are used as heaters and temperature sensors. The chip is externally cooled by forced air to achieve rapid temperature cycling. The transparency of the Pyrex makes it possible for using optical readout methods. The packaging is especially designed for easy handling, filling, power connection, temperature regulation and optical readout. The mass production of such silicon reactors could make single‐shot throwaway devices economically viable.
John Peter Cooney, David Oloke and Louis Gyoh
This study aims to demonstrate the possibility of showing the functionality of complex microbial groups, within ancient structures within a process of refurbishment on a heritage…
Abstract
Purpose
This study aims to demonstrate the possibility of showing the functionality of complex microbial groups, within ancient structures within a process of refurbishment on a heritage building information modelling (BIM) platform.
Design/methodology/approach
Both a qualitative and qualitative research method will be used throughout, as observational and scientific results will be obtained and collated. This path being; phenomena – acquisition tools – storage – analysis tools – literature. Using this methodology, one pilot study within the scope of demolition and refurbishment, using suitable methods of collecting and managing data (structural or otherwise), will be used and generated by various software and applications. The principle methods used for the identification of such micro-organisms will incorporate a polymerase chain reaction method (PCR), to amplify DNA and to identify any or all spores present. The BIM/historical BIM (HBIM) process will be used to create a remotely-based survey to obtain and collate data using a laser scanner to produce a three-dimensional point cloud model to evaluate and deduce the condition, make-up and stature of the monument. A documentation management system will be devised to enable the development of plain language questions and an exchange information requirement, to identify such documentation required to enable safe refurbishment and to give health and safety guidance. Four data sampling extractions will be conducted, two for each site, within the research, for each of the periods being assessed, that being the Norman and Tudor areas of the monument.
Findings
From laboratory PCR analysis, results show a conclusive presence of micro-organism groups and will be represented within a hierarchical classification, from kingdom to species.
Originality/value
The BIM/HBIM process will highlight results in a graphical form to show data collected, particularly within the PCR application. It will also create standardisation and availability for such data from ancient monuments to make available all data stored, as such analysis becomes substantially important to enable the production of data sets for comparison, from within the framework of this research.
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Zoi Kotsiri and Apostolos Vantarakis
This study aims to monitor seawater by determing two biological indicators, Escherichia coli and Enterococcus faecalis. The process of following standard procedures is mainly…
Abstract
Purpose
This study aims to monitor seawater by determing two biological indicators, Escherichia coli and Enterococcus faecalis. The process of following standard procedures is mainly time-consuming. Thus, there is a demand for a biosensor, an appropriate device for rapid and accurate results that can give information about the microbiological quality of seawater in an effective and rapid way.
Design/methodology/approach
In the gold standard method for seawater monitoring, the filter method is applied as a condensation step. In this work, the authors evaluated six types of common syringe filters for bacteria concentration and then the best filter was used for seawater analysis for E. coli and Enterococci with loop-mediated isothermal amplification (LAMP) polymerase chain reaction (PCR).
Findings
Cellulose acetate filter had the highest efficiency (98%) for bacterial concentration. The limit of detection of the LAMP method was 104/1,000 mL for both E. coli and E. faecalis. The proposed method could be used for the development of seawater biosensors with advantages such as a simple heating element and the speed that the LAMP PCR presents.
Originality/value
The suggested protocol is proposed in an integrated in situ system, a biosensor, for seawater quality determination.
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Mohammad Alshuniaber, Omar Alhaj, Qasem Abdallah and Haitham Jahrami
This study aims to investigate the antihypertensive effect of camel milk hydrolysate in rats with fructose-induced hypertension.
Abstract
Purpose
This study aims to investigate the antihypertensive effect of camel milk hydrolysate in rats with fructose-induced hypertension.
Design/methodology/approach
The antihypertensive effect of fermented camel milk was determined using 6 groups comprising 36 Wistar male rats. Blood pressure of rats was altered via exposure to a 10% fructose (w/v) diet in drinking water for 3 weeks before conducting 21 days of treatment. The authors conducted the experiment for short and long term using different doses of 800 and 1,200 mg/kg body weight. Serum was used to assay total cholesterol (TC), triglyceride (TG), glucose and insulin levels using standard biochemical kits.
Findings
The group that received 1,200 mg hydrolysate camel milk (HM) has significantly (p = 0.003) reduced systolic and diastolic blood pressure after a short exposure time (4–8 h). These effects were significantly (p = 0.005) comparable to the nifedipine (NIF) drug group. Similar long-term (21 days) effects on blood pressure were observed in 1,200 mg HM and NIF groups. Angiotensin-converting enzyme (ACE) activity and levels were also reduced in a correlation with blood pressure reduction only in HM1200 and HM800 treated groups. The authors observed no significant effect on blood pressure in groups receiving the 800 mg HM or 1,200 mg unhydrolyzed camel milk (UM). Rats receiving the 10% fructose diet showed significant differences from control rats regarding their blood biochemistry, including TG, TC, blood glucose and insulin levels. Rats in groups NIF, HM1200 and HM800 showed a significant (p < 0.05) reduction in serum glucose, insulin, TG and TC levels toward the baseline level.
Research limitations/implications
Further mechanistic investigation on the HM antihypertensive activity is highly recommended before suggesting HM as a product to reduce blood pressure. While drug–food interaction between HM and antihypertensive drugs, especially ACE inhibitors, is probable, UM seems not to affect blood pressure or ACE activity and therefore is expected to have no or minimal effects on the activity of other antihypertensive drugs. Investigation of ACE expression from various organs including lungs and leukocytes is highly recommended in future works using sodium dodecyl-sulfate polyacrylamide gel electrophoresis and western blot analysis or reverse transcription polymerase chain reaction.
Originality/value
No previous studies have measured the antihypertensive activity of milk hydrolysate mediated by the reduction of ACE activity and levels in plasma. Mechanisms involved in attenuating the levels of ACE warrant further investigation.
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Ahmed Attalah Hassan Al-Fhdawi and Adel Mashaan Rabee
The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.
Abstract
Purpose
The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.
Design/methodology/approach
Among 303 clinical and environmental samples 109 (61 + 48) isolates were identified as clinical and environmental P. aeruginosa isolates, respectively. Clinical samples were obtained from patients in the Al-Yarmouk hospital in Baghdad city, Iraq. Waste water from Al-Yarmouk hospital was used from site before treatment unit to collect environmental samples. The ability of producing biofilm at various pH levels was examined by microtiter plate and the prevalence of Alg D, Psl A and Pel A was determined by quantitative real time-polymerase chain reaction (qRT-PCR).
Findings
This study showed that the ability of clinical and environmental isolates to biofilm development was observed in 86.9% and 85.42% of clinical and environmental isolates, respectively. As well as, the environmental P. aeruginosa isolates showed the highest biofilm production at pH 7. Clinical isolates showed the highest genes expression of Alg D, Psl A and Pel A as compared to environmental isolates with pH change. In general, both clinical and environmental isolates formed biofilm and carried AlgD, PslA and PelA genes. Also, alkaline pH was favored for biofilm production.
Originality/value
There are very few studies done to find out the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa. This study is unique as it has highlighted the influence of environmental pH on the ability of clinical and environmental isolates to biofilm development and genes expression.
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TeckLok Wong, Megan Louise Devane, John Andrew Hudson, Paula Scholes, Marion Grace Savill and John D. Klena
This study describes a multiplex polymerase chain reaction (PCR) detection system combined with enrichment growth conditions for simultaneous detection and identification of C…
Abstract
This study describes a multiplex polymerase chain reaction (PCR) detection system combined with enrichment growth conditions for simultaneous detection and identification of C. jejuni, C. coli and thermotolerant Campylobacter in poultry pack rinses. The PCR primers were tested against a range of Campylobacter and non‐Campylobacter species, and PCR products were only amplified from target organisms. The sensitivity of the method was similar to that obtained by conventional plating procedures, but when used in combination with the MPN method of enumeration could detect levels down to 6 MPN/100 ml of rinse. The validation of 50 samples of chicken pack rinses demonstrated the versatility of this approach in microbiological surveys to yield data for risk assessments.
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