Correlation of Clinical Severity With Stool Microbiome Changes in Clostridioides difficile Infection.

CONTEXT.­: Clostridioides difficile infection (CDI) is the world-leading cause of infectious nosocomial diarrhea and pseudomembranous colitis. Antibiotics are the first line of treatment against CDI despite the high likelihood of antibiotic failure and/or recurrence. More data are needed to correlate clinical variables with 16S rRNA microbiome profiles in CDI-infected patients. OBJECTIVE.­: To determine the relationship(s) between a patient's clinical factors and the stool bacteriome of CDI-positive patients and CDI-negative patients with diarrheal symptoms. DESIGN.­: This study used stool samples and clinical data from 358 patients with nosocomial diarrhea, who were divided by their CDI diagnosis (CDI-negative: n = 180; CDI-positive; n = 178). The stool bacteriome was profiled by amplicon deep sequencing of the 16S rRNA gene, followed by correlating clinical data. RESULTS.­: The stool bacteriome was significantly different by severity assessment regardless of CDI status. Phyla and species varied significantly by CDI diagnosis. Severity, defined as a serum white blood cell count greater than 15 cells/µL and/or a creatinine level greater than 1.5 mg/dL, correlated significantly with dysbiosis of the stool bacteriome profile of CDI-positive patients compared to CDI-negative patients. Serum white blood cell count was significantly higher in patients with bacterial dysbiosis, and high levels of creatinine were associated with low bacteriome diversity. CONCLUSIONS.­: Clinical severity of CDI influences the stool microbiome of infected patients. To date, this study has the largest data set comparing 16S rRNA microbiome profiles and clinical variables between CDI-infected and noninfected individuals.

Active case detection of malaria in pregnancy using loop-mediated amplification (LAMP): a pilot outcomes study in South West Ethiopia.

BACKGROUND: 125 million women are pregnant each year in malaria endemic areas and are, therefore, at risk of Malaria in Pregnancy (MiP). MiP is the direct consequence of Plasmodium infection during pregnancy. The sequestration of Plasmodium falciparum parasites in the placenta adversely affects fetal development and impacts newborn birth weight. Importantly, women presenting with MiP commonly develop anaemia. In Ethiopia, the Ministry of Health recommends screening symptomatic women only at antenatal care visits with no formal intermittent preventive therapy. Since MiP can display low-level parasitaemia, current tests which include microscopy and RDT are challenged to detect these cases. Loop mediated isothermal Amplification (LAMP) technology is a highly sensitive technique for DNA detection and is field compatible. This study aims to evaluate the impact of active malaria case detection during pregnancy using LAMP technology in terms of birth outcomes. METHODS: A longitudinal study was conducted in two health centres of the Kafa zone, South West Ethiopia. Both symptomatic and asymptomatic pregnant women were enrolled in the first or second trimester and allocated to either Standard of Care (SOC-microscopy and RDT) or LAMP (LAMP, microscopy and RDT). Women completed at least three visits prior to delivery, and the patient was referred for treatment if Plasmodium infection was detected by any of the testing methods. The primary outcome was to measure absolute birth weight, proportion of low birth weight, and maternal/neonatal haemoglobin in each arm. Secondary outcomes were to assess the performance of microscopy and RDT versus LAMP conducted in the field. RESULTS: One hundred and ninety-nine women were included and assigned to either LAMP or SOC. Six were lost to follow up. In this cohort, 66.8% of women did not display any clinical symptoms and 70.9% were multi-parous. A reduced proportion of low birth weight newborns was observed in the LAMP group (0%) compared to standard of care (14%) (p <0.001). Improved neonatal haemoglobin was observed in the LAMP (13.1 g/dL) versus the SOC (12.8 g/dL) (p = 0.024) arm. RDT and microscopy had an analytical sensitivity of 66.7% and 55.6% compared to LAMP as a reference standard. CONCLUSIONS: These results support the use of highly sensitive tools for rapid on-site active case detection of MiP which may improve birth outcomes in the absence of IPT. However, further large-scale studies are required to confirm this finding.

Risk prediction for severe disease and better diagnostic accuracy in early dengue infection; the Colombo dengue study.

BACKGROUND: A major challenge in dengue management in resource limited settings is the confirmation of diagnosis. Clinical features of dengue often overlap with other infections and molecular diagnostic tools are not readily accessible to clinicians at hospitals. In addition, the prediction of plasma leakage in dengue is also difficult. Hematocrit level and ultrasound scans (combined with clinical parameters) are helpful to detect plasma leakage once it has happened, not before. METHODS: Colombo Dengue Study (CDS) is a prospective cohort study of clinically suspected adult dengue patients recruited from the National hospital of Sri Lanka (within the first 3 days of fever) that aimed to a) identify clinical and basic laboratory test parameters to differentiate dengue from non-dengue fever, b) evaluate the comparative efficacy of loop-mediated isothermal amplification (LAMP) for dengue diagnosis (vs. NS1 antigen test and RT-qPCR) and c) identify early associations that are predictive of plasma leakage or severe dengue. The basic laboratory tests considered here included hematological parameters, serum biochemistry and inflammatory markers. RESULTS: Only 70% of clinically suspected patients were confirmed as having dengue by either the NS1 antigen test or RT-qPCR. On a Bayesian latent class model which assumes no "gold standard", LAMP performed equally or better than RT-qPCR and NS1 antigen test respectively. When confirmed dengue patients were compared with others, the earlier group had significantly lower lymphocyte counts and higher aspartate aminotransferase levels (AST) within the first 3 days of fever. Confirmed dengue patients with plasma leakage had a lower mean age and a higher median baseline AST level compared to those without plasma leakage (p < 0.05). CONCLUSION: Clinical suspicion overestimates the true number of dengue patients. RT-LAMP is a potentially useful low-cost diagnostic tool for dengue diagnosis. Confirmed dengue patients had significantly higher AST levels and lower lymphocyte counts in early disease compared to others. In confirmed dengue patients, younger age and a higher AST level in early infection were associated with subsequent plasma leakage.

Microbiome of the placenta in pre-eclampsia supports the role of bacteria in the multifactorial cause of pre-eclampsia.

AIM: This study was aimed at detecting, identifying, quantifying and comparing the bacteria present in the placental tissues of women with pre-eclampsia with that of normotensive pregnant women. MATERIAL AND METHODS: Placental tissue samples were collected from 55 primiparous women with pre-eclampsia (cases) and 55 matched primiparous normotensive pregnant women (controls) at the time of delivery by cesarean section. Genotyping was carried out in two stages. First the samples were screened for the presence of bacteria by polymerase chain reaction (PCR) for the 16S rRNA gene. Next, the samples that were PCR-positive for the 16S rRNA gene were screened by next-generation sequencing on an Illumina MiSeq platform. RESULTS: Seven (12.7%) placental tissue samples from women with pre-eclampsia were PCR-positive. All the placental samples from control women were negative (P = 0.006). The complete microbiome of the seven samples was revealed through next-generation sequencing. The organisms that were present included Bacillus cereus, Listeria, Salmonella, Escherichia (all of which are usually associated with gastrointestinal infection); Klebsiella pneumonia and Anoxybacillus (both of which are usually associated with respiratory tract infections); and Variovorax, Prevotella, Porphyromonas, and Dialister (all of which are usually associated with periodontitis). CONCLUSIONS: This study confirms the presence of bacteria in the placental tissues of a subset of women with pre-eclampsia and supports the role of bacteria in the multifactorial cause of pre-eclampsia.