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Diseases caused by Rickettsiales are often overlooked, although they pose important public health concerns. The Rickettsiales family comprises a broad range of intracellular bacteria with distinct evolutionary adaptations, making the development of treatment measures to combat infections, such as vaccines or antibiotics, a challenge. Interestingly, the outer membrane protein A (OmpA) was found to exist in the cell surface of most human pathogenic bacteria in the order Rickettsiales. However, knowledge about OmpA in each species and strain is scattered and ambiguous. In this study, we systematically compiled the existing information on OmpA and its relationship with human pathogenic rickettsiae to serve as a reference for future research. A comprehensive literature search was conducted using specific keywords across five databases. According to the literature, OmpA of spotted fever group rickettsia plays a crucial role as an adhesin and invasin that directly interacts with the surface of mammalian host cells to mediate bacterial localization in host cells. The presence of a premature stop codon in the amino acid sequence resulted in the secretion of non-functional OmpA, which is one of the main reasons for rickettsial strains or species to become avirulent. Similarly, OmpA also functions as an important adhesin in the Anaplasma family when it interacts with the sLex and sLex-like glycan of myeloid and endothelial cells, respectively. However, the OmpA of Anaplasma must be co-functional with the other two adhesins to promote bacterial internalization. Interestingly, certain sites in the amino acid residues of Ehrlichia and Orientia OmpA are predicted to be homologous to the binding domain region of Anaplasma OmpA. It is therefore suggested that OmpA is an important adhesin for bacteria to bind to their specific mammalian host cells.

Objective: To investigate the interrelationship between cardiovascular health awareness, risk perception, behavioural intention, and INTERHEART risk stratification in a middle-aged adult population in Malaysia. Methods: A cross-sectional survey with convenience sampling was conducted during November 2022 and January 2023. Participants completed validated questionnaires assessing cardiovascular health awareness, risk perception of cardiovascular diseases, behavioural intention towards adopting healthy habits, and INTERHEART risk stratification score (IHRS) based on established risk factors. A total of 602 respondents were included in the final analysis. Data were analysed with independent t-test/one-way ANOVA or Mann- Whitney/Kruskai-Wailis to test the differences, Pearson correlation or linear regression test to analyze the association of independent and dependent variables. Results: There was a significant positive correlation between medical knowledge related to cardiovascular disease (CVD) and knowledge related to CVD risk prevention, risk perception, behavioural intention and IHRS (P

Central nervous system (CNS) infection is a serious illness that can lead to death. CNS infections include meningitis, encephalitis, brain abscesses and myelitis. These diseases are caused by causative agents like bacteria, fungi, parasites, and protozoa, but most commonly by viral infections. To combat this issue, accurate diagnosis of etiological agents at an early stage is crucial for appropriate treatment, control of the disease and prevent from becoming life-threatening to the patients. This review paper summarises the main laboratory diagnostic methods for CNS infections caused by viruses ranging from conventional to molecular methods. Conventional isolation methods are considered the ‘gold standard’ as they provide accurate evidence, but require highly skilled personnel, are time-consuming, critical in cell type selection and are useless for non-cultivable viruses. Electron microscopy allows recognition of viral morphology and ultrastructural details as the principle of virus identification through negative staining or thin section technique (suitable for tissue or cell specimens). However, it offers low sensitivity and requires at least 106 virions per millilitre or milligram in the specimen to be detectable by microscopy. Immunological-based methods have been extensively applied for viral diagnosis by detecting the antiviral antibodies or viral antigens in clinical samples. While these methods provided high sensitivity and specificity, the incubation and window period of an infection may give false-negative results. Lastly, molecular detections have many advantages such as high sensitivity, specificity, rapid, require a small amount of sample, simultaneous detection of multiple different viruses, and produce both qualitative and quantitative results.

Objective: To determine the degree of knowledge in the usage of pulse oximeter as a home assessment tool among the community in Malaysia. Methods: A cross-sectional survey was conducted in November 2021. The questionnaire assessed the knowledge in using pulse oximeters, user experience and opinions in using pulse oximeter as a home assessment tool during the pandemic. Results: A total of 504 respondents were included in the study, and the mean score in knowledge related to application of pulse oximetry was 73.00%, while the mean score in knowledge related to factors affecting pulse oximetry readings was only 38.51%. A total of 90.5% of the respondents recognised normal pulse rate and 88.5% knew the blood oxygen saturation levels of a healthy adult, while 69.4% recognised the definition of silent hypoxia. In addition, the majority of the respondents agreed that factors such as poor blood circulation (71.2%), excessive movements (69.8%), and hand position (60.7%) affected oximetry readings. However, 61.7%, 81.7%, 77.2% and 76.8% of the respondents could not identify nail polish, skin colour, skin thickness and tattoos as factors that may affect oximetry readings respectively. Conclusions: The respondents showed a satisfactory level of knowledge related to application of pulse oximetry, but a poor level of knowledge related to factors affecting pulse oximetry readings among the community in Malaysia. Continuous efforts in educating the community on the correct use of pulse oximeters are crucial for appropriate home assessment and avoiding unnecessary stress.

Diseases caused by Rickettsiales are often overlooked, although they pose important public health concerns. The Rickettsiales family comprises a broad range of intracellular bacteria with distinct evolutionary adaptations, making the development of treatment measures to combat infections, such as vaccines or antibiotics, a challenge. Interestingly, the outer membrane protein A (OmpA) was found to exist in the cell surface of most human pathogenic bacteria in the order Rickettsiales. However, knowledge about OmpA in each species and strain is scattered and ambiguous. In this study, we systematically compiled the existing information on OmpA and its relationship with human pathogenic rickettsiae to serve as a reference for future research. A comprehensive literature search was conducted using specific keywords across five databases. According to the literature, OmpA of spotted fever group rickettsia plays a crucial role as an adhesin and invasin that directly interacts with the surface of mammalian host cells to mediate bacterial localization in host cells. The presence of a premature stop codon in the amino acid sequence resulted in the secretion of non-functional OmpA, which is one of the main reasons for rickettsial strains or species to become avirulent. Similarly, OmpA also functions as an important adhesin in the Anaplasma family when it interacts with the sLex and sLex -like glycan of myeloid and endothelial cells, respectively. However, the OmpA of Anaplasma must be co-functional with the other two adhesins to promote bacterial internalization. Interestingly, certain sites in the amino acid residues of Ehrlichia and Orientia OmpA are predicted to be homologous to the binding domain region of Anaplasma OmpA. It is therefore suggested that OmpA is an important adhesin for bacteria to bind to their specific mammalian host cells. [ABSTRACT FROM AUTHOR]

Central nervous system (CNS) infection is a serious illness that can lead to death. CNS infections include meningitis, encephalitis, brain abscesses and myelitis. these diseases are caused by causative agents like bacteria, fungi, parasites, and protozoa, but most commonly by viral infections. to combat this issue, accurate diagnosis of etiological agents at an early stage is crucial for appropriate treatment, control of the disease and prevent from becoming life-threatening to the patients. this review paper summarises the main laboratory diagnostic methods for CNS infections caused by viruses ranging from conventional to molecular methods. Conventional isolation methods are considered the 'gold standard' as they provide accurate evidence, but require highly skilled personnel, are time-consuming, critical in cell type selection and are useless for non-cultivable viruses. electron microscopy allows recognition of viral morphology and ultrastructural details as the principle of virus identification through negative staining or thin section technique (suitable for tissue or cell specimens). However, it offers low sensitivity and requires at least 106 virions per millilitre or milligram in the specimen to be detectable by microscopy. Immunological-based methods have been extensively applied for viral diagnosis by detecting the antiviral antibodies or viral antigens in clinical samples. While these methods provided high sensitivity and specificity, the incubation and window period of an infection may give false-negative results. lastly, molecular detections have many advantages such as high sensitivity, specificity, rapid, require a small amount of sample, simultaneous detection of multiple different viruses, and produce both qualitative and quantitative results. [ABSTRACT FROM AUTHOR]