Construction and evaluation of in house pcrbased diagnostic method for detection of helicobacter pylori infection

The specific primers for He/icobacter pylori were constructed. The primer were standardized and optimized by using ATCC strains. The PCR were performed to eighty-nine antral biopsy samples from patients suspected to have gastric ulcer. Simultaneously, histopathological examination was performed on the biopsy samples. The agreement between the two test methods was measured

Lateral flow immunoassay for naked eye detection of Mycobacterium tuberculosis

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. Detection and control of infectious diseases is a major problem, especially in developing countries. Lateral flow immunoassay (LFIA) has been introduced as a handheld immunoassay-based point-of-care platform for an automated detection of TB. The CFP10-ESAT6 antigen of M. tuberculosis was used as the target in early detection of TB using LFIA strip-based POC strategy. An interesting platform based on optical signals is implemented as a colour change in the detection area that is visible to the naked eye. The gold nanoparticles (AuNPs) were used as the colour probe for the detection of a target of interest. The high-resolution transmission electron microscopy (HRTEM) image and ultraviolet-visible spectrophotometer (UV-Vis) analysis confirmed that the synthesized AuNPs were appropriate for the immunoassay designed. The platform consists of AuNPs conjugated with specific antibodies (Ab) to capture the antigen of M. tuberculosis. Under the capillary effect, sandwich immunoreactions of AuNP-Ab-antigen were performed on the test pad of the immunostrip, which can be observed by the colour signal on the test line of the strip with a short assay time. Furthermore, the newly developed biosensor was utilized in CFP10-ESAT6 antigen detection in human sputum specimens with satisfactory results. The characteristic coloured bands enable visual detection (naked eye) of target analyte without instrumentation. This noninvasive diagnose system which is sputum-based detection could provide user-friendly and affordable diagnostic tests in developing countries

Health and safety: the use of metagenomics approach to study the spectrum of water microbiodata towards ensuring the post-flood pathogen-free water sources

Recent massive flood in kelantan lead to contamination of water supply to the public. The magnitude of of the contamination is very difficult to be measured by the conventional coliform count method. We used a metagenomic approach to estimate the burden of microbiological contamination of the water following the massive flood. The water sampled during the massive blood and 6 months after the incidence extracted, analysed and compared. The results showed that eventhough Pseudomas predominates the entire microorganisms population during flood and non flood water, there are few pathogenic organisms that really need special attention. The metagenomics approached is very usefull as it provide the full spectrum of the diversity of the organisms presents in the sampled water. The evidence is solid and have a very high value both to the community and also to the scientist

In-vitro antimicrobial effectiveness of herbal-based mouthrinses against oral microorganisms

Objective: To evaluate the in vitro antimicrobial effectiveness of commercial herbal-based mouthrinses against oral microorganisms. Methods: A total of three mouthrinses (OX, Pesona and Watsons) were tested for their antimicrobial activity against six oral organisms, Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Lactobacillus salivarius (L. salivarius), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Candida albicans (C. albicans) by standard agar-disk diffusion assay. Oradex mouthrinse containing 0.12% chlorhexidine gluconate and sterile distilled water was served as positive and negative controls, respectively. Results: All mouthrinse formulations were effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans. Among the tested mouthrinses, Pesona was the only effective mouthrinse against S. aureus and P. aeruginosa, similar to Oradex mouthrinse. Pesona mouthrinse formulation appears to be as effective as Oradex mouthrinse formulation to kill S. aureus and P. aeruginosa. Statistical analysis showed no significant difference among the tested formulations regarding their antimicrobial activities (P > 0.05). Conclusions: Pesona was not the only herbal mouthrinse effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans in vitro. All tested formulations were effective against those strains. Our findings may serve as a guide for selecting a kind of herbal mouthrinses as well as providing information to the dental professionals about the efficacy of these products

Risk Factors Associated with Defaulted Follow-Up and Sharp Injury Management among Health Care Workers in a Teaching Hospital in Northeastern Malaysia

Sharp injury is a serious occupational risk for healthcare workers (HCWs). This study aimed to determine the distribution and associated factors of sharp injury cases among HCWs working at a teaching hospital in northeastern Malaysia. This was a retrospective cohort study on all reported sharp injury cases from 2015 to 2020. The secondary data were examined using descriptive and multiple logistic regression. Statistical significance was determined for associated factors of HCWs who did not attend immediate treatment after a sharp injury or any of the subsequent follow-up variables, with a p-value of less than 0.05. A total of 286 cases fulfilled the study criteria. The mean (SD) age of sharp injury was 29.4 (5.38) years. The overall defaulted rate for follow-up was 51.4%. Multiple logistic regression revealed a significant relationship between defaulted follow up on sharp injury management and job category as well as the type of device used. Being a doctor (Adj OR 2.37; 95% CI: 1.40, 4.03; p = 0.010) and those using other sharp instruments such as Coupland and drip sets (Adj OR 4.55; 95% CI: 1.59, 13.02; p = 0.005) had a higher odds to default follow up on sharp injury management. In conclusion, although there is a link between defaulting the follow-up and both the work category and the type of device that caused the injury, a deeper analysis is needed to uncover any additional factors and determine the appropriate intervention strategies to ensure follow up adherence

Simultaneous amperometric aptasensor based on diazonium grafted screen-printed carbon electrode for detection of CFP10 and MPT64 biomarkers for early tuberculosis diagnosis

Early diagnosis is highly crucial for life-saving and transmission management of tuberculosis (TB). Despite the low sensitivity and time-consuming issues, TB antigen detection still relies on conventional smear microscopy and culture techniques. To address this limitation, we report the development of the first amperometric dual aptasensor for the simultaneous detection of Mycobacterium tuberculosis secreted antigens CFP10 and MPT64 for better diagnosis and control of TB. The developed sensor was based on the aptamers–antibodies sandwich assay and detected by chronoamperometry through the electrocatalytic reaction between peroxidase-conjugated antibodies, H2O2, and hydroquinone. The CFP10 and MPT64 aptamers were immobilized via carbodiimide covalent chemistry over the disposable dual screen-printed carbon electrodes modified with a 4-carboxyphenyl diazonium salt. Under optimized conditions, the aptasensor achieved a detection limit of 1.68 ng mL−1 and 1.82 ng mL−1 for CFP10 and MPT64 antigens, respectively. The developed assay requires a small sample amount (5 µL) and can be easily performed within 2.5 h. Finally, the dual aptasensor was successfully applied to clinical sputum samples with the obtained diagnostic sensitivity (n = 24) and specificity (n = 13) of 100%, respectively, suggesting the readiness of the developed assay to be used for TB clinical application

Immuno Nanosensor for the Ultrasensitive Naked Eye Detection of Tuberculosis

In the present study, a beneficial approach for the ultrasensitive and affordable naked eye detection and diagnosis of tuberculosis (TB) by utilizing plasmonic enzyme-linked immunosorbent assay (ELISA) via antibody-antigen interaction was studied. Here, the biocatalytic cycle of the intracellular enzymes links to the formation and successive growth of the gold nanoparticles (GNPs) for ultrasensitive detection. The formation of different colored solutions by the plasmonic nanoparticles in the presence of enzyme labels links directly to the existence or non-existence of the TB analytes in the sample solutions. For disease detection, the adapted protocol is based mainly on the conventional ELISA procedure that involves catalase-labeled antibodies, i.e., the enzymes consume hydrogen peroxide and further produce GNPs with the addition of gold (III) chloride. The amount of hydrogen peroxide remaining in the solution determines whether the GNPs solution is to be formed in the color blue or the color red, as it serves as a confirmation for the naked eye detection of TB analytes. However, the conventional ELISA method only shows tonal colors that need a high concentration of analyte to achieve high confidence levels for naked eye detection. Also, in this research, we proposed the incorporation of protein biomarker, Mycobacterium tuberculosis ESAT-6-like protein esxB (CFP-10), as a means of TB detection using plasmonic ELISA. With the use of this technique, the CFP-10 detection limit can be lowered to 0.01 µg/mL by the naked eye. Further, our developed technique was successfully tested and confirmed with sputum samples from patients diagnosed with positive TB, thereby providing enough evidence for the utilization of our technique in the early diagnosis of TB disease

Electrochemical immunosensor for detection of Mycobacterium tuberculosis

A rapid and sensitive sandwich electrochemical immunosensor was developed based on the fabrication of the graphene/polyaniline (GP/PANI) nanocomposite onto screen-printed gold electrode (SPGE) for detection of Mycobacterium tuberculosis (M. tuberculosis) antigen. The chemical bonding and morphology of GP/PANI-modified SPGE were studied by Raman spectroscopy and field enhance scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX), respectively. From both studies, it clearly showed that GP/PANI was successfully coated onto SPGE through drop cast technique. Cyclic voltammetry (CV) was used to study the electrochemical properties of the modified electrode. The effective surface area for GP/PANI-modified SPGE was enhanced when compared with bare SPGE. Differential pulse voltammetry (DPV) was used to detect the M. tuberculosis antigen. This proposed electrochemical immunosensor is sensitive, low sample volume, rapid, and disposable, which is suitable for tuberculosis detection in real samples

Surface-enhanced Carboxyphenyl diazonium functionalized screen-printed carbon electrode for the screening of tuberculosis in sputum samples

Curbing tuberculosis (TB) requires a combination of good strategies, including a proper prevention measure, diagnosis, and treatment. This study proposes an improvised tuberculosis diagnosis based on an amperometry approach for the sensitive detection of MPT64 antigen in clinical samples. An MPT64 aptamer specific to the target antigen was covalently attached to the carboxyphenyl diazonium-functionalized carbon electrode via carbodiimide chemistry. The electrochemical detection assay was adapted from a sandwich assay format to trap the antigen between the immobilized aptamer and horseradish peroxidase (HRP) tagged polyclonal anti-MPT64 antibody. The amperometric current was measured from the catalytic reaction response between HRP, hydrogen peroxide, and hydroquinone, which is used as an electron mediator. From the analysis, the detection limit in the measurement buffer was 1.11 ng mL-1. Additionally, the developed aptasensor exhibited a linear relationship between the current signal and the MPT64 antigen-spiked serum concentration ranging from 10 to 150 ng mL-1 with a 1.38 ng mL-1 detection limit. Finally, an evaluation using the clinical sputum samples from both TB (+) and TB (-) individuals revealed a sensitivity and specificity of 88% and 100%, respectively. Based on the analysis, the developed aptasensor was found to be simple in its fabrication, sensitive, and allowed for the efficient detection and diagnosis of TB in sputum samples