Introduction: Onychomycosis is a debilitating, difficult-to-treat nail fungal infection with increasing prevalence worldwide. The main etiological agents are dermatophytes, which are common causative pathogens in superficial fungal mycoses. Conventional detection methods such as fungal culture have low sensitivity and specificity and are time-consuming. Aim: The main objective of this study was to design, develop and validate a real-time probe-based multiplex qPCR assay for the detection of dermatophytes and Fusarium species. Methodology: The performance characteristics of the qPCR assays were evaluated. The multiplex qPCR assays targeted four genes (assay 1: pan-dermatophytes/Fusarium spp.; assay 2: Trichophyton rubrum/Microsporum spp.). Analytical validation was accomplished using 150 fungal isolates and clinical validation was done on 204 nail specimens. The performance parameters were compared against the gold standard (fungal culture) and expanded gold standard (culture in conjunction with sequencing). Results: Both the single-plex and multiplex qPCR assays performed well especially when compared against the expanded gold standard. Among the 204 tested nail specimens, the culture method showed that 125 (61.3 %) were infected with at least one organism, of which 40 yielded positive results for dermatophytes and Fusarium spp. These target organisms detected include 20 dermatophytes and 22 Fusarium spp. The developed qPCR assays demonstrated excellent limit of detection, efficiency, coefficient of determination, analytical and clinical sensitivity and specificity. Conclusion: The multiplex qPCR assays were reliable for the diagnosis of onychomycosis, with shorter turn-around time as compared to culture method. This aids in the planning of treatment strategies to achieve optimal therapeutic outcome.
Background and Aim: Perturbance in the composition of human gut microbiota has been associated with metabolic disorders such as obesity, diabetes mellitus, and insulin resistance. The objectives of this study are to examine the effects of ethnicity, central obesity, and recorded dietary components on potentially influencing the human gut microbiome. We hypothesize that these factors have an influence on the composition of the gut microbiome.Methods: Subjects of Chinese (n = 14), Malay (n = 10), and Indian (n = 11) ancestry, with a median age of 39 years (range: 22–70 years old), provided stool samples for gut microbiome profiling using 16S rRNA sequencing and completed a dietary questionnaire. The serum samples were assayed for a panel of biomarkers (interleukin‐6, tumor necrosis factor alpha, adiponectin, cleaved cytokeratin 18, lipopolysaccharide‐binding protein, and limulus amebocyte lysate). Central obesity was defined by waist circumference cut‐off values for Asians.Results: There were no significant differences in Shannon alpha diversity for ethnicity and central obesity and no associations between levels of inflammatory cytokines and obesity. The relative abundances of Anaerofilum (P = 0.02), Gemellaceae (P = 0.02), Streptococcaceae (P = 0.03), and Rikenellaceae (P = 0.04) were significantly lower in the obese group. From principle coordinate analysis, the effects of the intake of fiber and fat/saturated fat were in contrast with each other, with clustering of obese individuals leaning toward fiber.Conclusion: The study demonstrated that there were differences in the gut microbiome in obese individuals. Certain bacterial taxa were present in lower abundance in the group with central obesity. Fiber and fat/saturated fat diets were not the key determinants of central obesity.
20 May 2021 in Transactions of the Royal Society of Tropical Medicine and Hygiene
Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is a significant cause of mortality and morbidity globally. A microbial cause was not determined in a sizable percentage of patients with CAP; there are increasing data to suggest regional differences in bacterial aetiology. We devised a multiplex real-time PCR assay for detecting four microorganisms (Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and Burkholderia pseudomallei) of relevance to CAP infections in Asia. Analytical validation was accomplished using bacterial isolates (n=10–33 of each target organism for analytical sensitivity and n=117 for analytical sensitivity) and clinical validation using 58 culture-positive respiratory tract specimens. The qPCR assay exhibited 100% analytical sensitivity and analytical specificity, and 100% clinical sensitivity and 94–100% clinical specificity. The limit of detection and efficiency for the multiplex PCR assay were 3–33 CFU/mL and 93–110%, respectively. The results showed that the PCR-based method had higher sensitivity than traditional culture-based methods. The assay also demonstrated an ability to semiquantify bacterial loads. We have devised a reliable laboratory-developed multiplex qPCR assay, with a turnaround time of within one working day, for detection of four clinically important CAP-associated microorganisms in Asia. The availability of a test with improved diagnostic capabilities potentially leads to an informed choice of antibiotic usage and appropriate management of the patient to achieve a better treatment outcome and financial savings.
Drug resistance is a major hurdle to the success of chemotherapy. The permeability glycoprotein (P-gp) is an important factor dictating drug access to the cells, as it controls the efflux of chemotherapeutic agents against the concentration gradient. Pmd1, a P-gp-like protein, was recently isolated as a doxorubicin resistance gene in fission yeast. Although the null mutant of pmd1 (Δpmd1) exhibited sensitivity to doxorubicin, it showed an unexpectedly high resistance to the drug at relatively high concentrations. The data presented here suggest that this is due to the presence of cooperative processes that can complement and counteract drug cytotoxicity in the absence of Pmd1. One such factor, Rav1, is an essential factor in controlling the assembly of the pH-regulating transporter vacuolar-ATPase (V-ATPase) in fission yeast. The simultaneous disruption of Pmd1 and Rav1 resulted in a prominent accumulation of doxorubicin in the cytoplasm of cells, accompanied by a decline in cell viability. With concurrent treatment of pharmacological inhibitors in human cervical cancer cells, P-gp and V-ATPase were further shown to act synergistically to sensitize cells to doxorubicin also in the human cells. Furthermore, a novel Cornichon-like protein SPAC2C4.05 (herein named as Cor1) was demonstrated for the first time to be involved in the interaction with P-gp and V-ATPase to counteract doxorubicin-dependent cytotoxicity. Therefore this study identified a molecular cooperation between multiple membrane transporter proteins that confers chemoresistance to cells against the chemical insult of doxorubicin. Interestingly, this network exhibited differential effects to doxorubicin as compared with its close epimeric analog epirubicin, suggestive of the intricacy of the drug response regulated by this synergistic interaction. A model is discussed on how the versatility of this network can differentiate closely related chemical drug structures yet allow for the robustness to counteract a vast range of drugs.
Prolonged surgery is a known risk of pressure ulcer formation. Pressure ulcers affect the quality of life, are a significant cause of morbidity and mortality, and pose a burden on the healthcare system. This study aimed to compare the effectiveness of an alternating pressure (AP) overlay with Gel pad against the Gel pad in reducing interface pressure (IP) during prolonged surgery. A total of 180 participants from a tertiary hospital were randomized to AP overlay with Gel pad group (n = 90) and Gel pad group (n = 90). Patients were placed supine on the pressure redistributing surfaces, and IP data under the sacrum and ischial tuberosities were collected at an interval of 30 min from 0 min up to a maximum of 570 min. Based on data from 133 participants, the average IPs during all the deflation cycles of the AP overlay (with Gel pad) were significantly lower than the average continuous IP recorded for Gel pad throughout the measuring period (p < 0.001). Only three patients (2.26% of study participants) - Gel pad group (n = 2; 2.99%) and AP overlay with Gel pad group (n = 1; 1.52%) developed post-operative pressure ulcer (p = 0.5687). The lower IP during deflation cycles of the AP overlay (with Gel pad) suggests its potential effectiveness in preventing pressure ulcer formation in patients undergoing prolonged surgery. The prevention and reduction of pressure ulcers will have a considerable impact on the improved quality of life and cost savings for the patient. The study findings may facilitate the formulation of policies for preventing pressure ulcer development in the perioperative setting.