Abstract The incidence of locally acquired dengue infections increased during the last decade in the United States, compelling a sustained research effort on the dengue mosquito vector, Aedes aegypti, and its microbiome, which has been shown to influence virus transmission success. We examined the ‘metavirome’ of four populations of Ae. aegypti mosquitoes collected in 2016-2017 from Manatee County, Florida. Unexpectedly, we discovered that dengue virus serotype 4 (DENV4) was circulating in these mosquito populations, representing the first documented case of such a phenomenon in the absence of a local DENV4 human case in this county over a two-year period. We confirmed that all of the mosquito populations carried the same DENV4 strain, assembled its full genome, validated infection orthogonally by reverse transcriptase PCR, traced the virus origin, estimated the time period of its introduction to the Caribbean region, as well as explored the viral genetic signatures and mosquito-specific virome associations that potentially mediated DENV4 persistence in mosquitoes. We discuss the significance of prolonged maintenance of these DENV4 infections in Ae. aegypti that occurred in the absence of a DENV4 human index case in Manatee County with respect to the inability of current surveillance paradigms to detect mosquito vector infections prior to a potential local outbreak. Importance Since 1999, dengue outbreaks in the continental United States (U.S.) involving local transmission have occurred episodically and only in Florida and Texas. In Florida, these episodes appear to be coincident with increased introductions of dengue virus into the region through human travel and migration from endemic countries. To date, the U.S. public health response to dengue outbreaks is largely reactive, and implementation of comprehensive arbovirus surveillance in advance of predictable transmission seasons, which would enable proactive preventative efforts, remains unsupported. The significance of our finding is that it is the first documented report of non-outbreak DENV4 transmission and maintenance within a local mosquito vector population in the continental U.S.in the absence of a human case during a two-year time period. Our data suggest that molecular surveillance of mosquito populations in high-risk, high tourism areas of the U.S., may allow for proactive, targeted vector control before potential arbovirus outbreaks.
Abstract Conventional antibiotics are ineffective against non‐replicating bacteria (for example, bacteria within biofilms). We report a series of halogenated phenazines (HP), inspired by marine antibiotic 1 , that targets persistent bacteria. HP 14 demonstrated the most potent biofilm eradication activities to date against MRSA, MRSE, and VRE biofilms (MBEC=0.2–12.5 μM), as well as the effective killing of MRSA persister cells in non‐biofilm cultures. Frontline MRSA treatments, vancomycin and daptomycin, were unable to eradicate MRSA biofilms or non‐biofilm persisters alongside 14 . HP 13 displayed potent antibacterial activity against slow‐growing M. tuberculosis (MIC=3.13 μM), the leading cause of death by bacterial infection around the world. HP analogues effectively target persistent bacteria through a mechanism that is non‐toxic to mammalian cells and could have a significant impact on treatments for chronic bacterial infections.
Introduction: Non-motor symptoms of Parkinson's disease (PD) such as gastrointestinal (GI) dysfunction are common, yet little is known about how modifying dietary intake impacts PD symptoms. The aim of this study in individuals with PD was to determine whether a Mediterranean diet intervention is feasible and affects GI function, intestinal permeability and fecal microbial communities. Methods: A single-arm, 5-week Mediterranean diet intervention study was conducted in eight people with PD. Daily and weekly questionnaires were administered to determine changes in GI symptoms. Urine and stool samples were collected at baseline and after 5 weeks to assess intestinal permeability and fecal microbial communities. Additionally, live-in partners of the participants with PD were matched as controls (n = 8) for baseline urine and stool samples. Results: Participants with PD increased intake of Mediterranean diet based on adherence scores from baseline to week 5 (4.4 ± 0.6 vs. 11.9 ± 0.7; P < 0.01 with >10 representing good adherence), which was linked with weight loss (77.4 kg vs. 74.9 kg, P = 0.01). Constipation syndrome scores decreased after 5 weeks (2.3 ± 0.5 vs. 1.5 ± 0.3; P = 0.04). Bilophila, was higher at baseline in PD (0.6 ± 0.1% vs. 0.2 ± 0.1% P = 0.02) and slightly decreased after the diet intervention (0.5 ± 0.1%; P = 0.01). Interestingly, the proportion of Roseburia was significantly lower in PD compared to controls (0.6 ± 0.2% vs. 1.6 ± 0.3%; P = 0.02) and increased at week 5 (0.9 ± 0.2%; P < 0.01). No differences were observed for markers of intestinal permeability between the control and PD groups or post-intervention. Conclusions: Short-term Mediterranean diet adherence is feasible in participants with PD; correlated with weight loss, improved constipation, and modified gut microbiota. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT03851861.
Intestinal luminal microbiota likely contribute to the etiology of necrotizing enterocolitis (NEC), a common disease in preterm infants. Microbiota development, a cascade of initial colonization events leading to the establishment of a diverse commensal microbiota, can now be studied in preterm infants using powerful molecular tools. Starting with the first stool and continuing until discharge, weekly stool specimens were collected prospectively from infants with gestational ages ≤32 completed weeks or birth weights≤1250 g. High throughput 16S rRNA sequencing was used to compare the diversity of microbiota and the prevalence of specific bacterial signatures in nine NEC infants and in nine matched controls. After removal of short and low quality reads we retained a total of 110,021 sequences. Microbiota composition differed in the matched samples collected 1 week but not <72 hours prior to NEC diagnosis. We detected a bloom (34% increase) of Proteobacteria and a decrease (32%) in Firmicutes in NEC cases between the 1 week and <72 hour samples. No significant change was identified in the controls. At both time points, molecular signatures were identified that were increased in NEC cases. One of the bacterial signatures detected more frequently in NEC cases (p<0.01) matched closest to γ-Proteobacteria. Although this sequence grouped to the well-studied Enterobacteriaceae family, it did not match any sequence in Genbank by more than 97%. Our observations suggest that abnormal patterns of microbiota and potentially a novel pathogen contribute to the etiology of NEC.
Abstract Conventional antibiotics are ineffective against non‐replicating bacteria (for example, bacteria within biofilms). We report a series of halogenated phenazines (HP), inspired by marine antibiotic 1 , that targets persistent bacteria. HP 14 demonstrated the most potent biofilm eradication activities to date against MRSA, MRSE, and VRE biofilms (MBEC=0.2–12.5 μM), as well as the effective killing of MRSA persister cells in non‐biofilm cultures. Frontline MRSA treatments, vancomycin and daptomycin, were unable to eradicate MRSA biofilms or non‐biofilm persisters alongside 14 . HP 13 displayed potent antibacterial activity against slow‐growing M. tuberculosis (MIC=3.13 μM), the leading cause of death by bacterial infection around the world. HP analogues effectively target persistent bacteria through a mechanism that is non‐toxic to mammalian cells and could have a significant impact on treatments for chronic bacterial infections.
To investigate the efficacy of phage supplementation in reducing pathogen numbers, mice were treated via oral gavage with a Listeria monocytogenes phage preparation (designated ListShield) before being orally infected with L. monocytogenes . The concentrations of L. monocytogenes in the liver, spleen, and intestines were significantly lower (P<.05) in the phage-treated than in the control mice. Phage and antibiotic treatments were similarly effective in reducing the levels of L. monocytogenes in the internal organs of the infected mice. However, the significant weight loss detected in the control and antibiotic-treated groups was not observed in the infected, ListShield-treated mice. Long-term (90 days), biweekly treatment of uninfected mice with ListShield did not elicit detectable changes in the microbiota of their large intestines or deleterious changes in their health. Our data support the potential feasibility of using bacteriophages to control proliferation of L. monocytogenes in mice without affecting commensal microbiota composition.
Abstract Enterobacteriaceae are among the first colonizers of neonate intestine. Members of this family, such as Escherichia and Klebsiella , are considered pathobionts and as such are capable of inducing local and systemic disease under specific colonization circumstances. Interplay between developing microbiota and pathogenic function of pathobionts are poorly understood. In this study, we investigate the functional interaction between various colonization patterns on an early colonizer, K . pneumoniae . K . pneumoniae 51-5 was isolated from stool of a healthy, premature infant, and found to contain the genotoxin island pks associated with development of colorectal cancer. Using intestinal epithelial cells, macrophages, and primary splenocytes, we demonstrate K . pneumoniae 51-5 upregulates expression of proinflammatory genes in vitro . Gnotobiotic experiments in Il10 −/− mice demonstrate the neonate isolate induces intestinal inflammation in vivo , with increased expression of proinflammatory genes. Regulation of microbiota assembly revealed K . pneumoniae 51-5 accelerates onset of inflammation in Il10 −/− mice, most significantly when microbiota is naturally acquired. Furthermore, K . pneumoniae 51-5 induces DNA damage and cell cycle arrest. Interestingly, K . pneumoniae 51-5 induced tumors in Apc Min /+ ; Il10 −/− mice was not significantly affected by absence of colibactin activating enzyme, ClbP. These findings demonstrate pathogenicity of infant K . pneumoniae isolate is sensitive to microbial colonization status.
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