Familial Transmission of emm12 Group A Streptococcus.
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ABSTRACT:
SUBMITTER: Duployez C
PROVIDER: S-EPMC5621563 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Group B Streptococcus (GBS), is a leading cause of neonatal death and an emerging pathogen in adults. Additionally, GBS is a bovine pathogen causing intramammary infections. The likelihood of GBS interspecies transmission is largely unknown. We explored the potential transmission of GBS between cattle and people on dairy farms in Colombia and compared the antimicrobial resistance (AMR) profiles of isolates from both host species. Across 33 farms, throat swabs and rectal swabs were collected from 191 people, and rectal swabs and composite milk samples from 2092 cattle, yielding 60 human isolates and 301 bovine isolates. The majority (64%) of isolates belonged to shared sequence types (ST). Sequence type (ST) 1 was the most common strain in both host species, suggesting that interspecies transmission may be possible. Two members of the bovine-specific clonal complex 61/67 were detected in human samples (ST718 and ST1175), providing evidence for the lack of genuine species barriers. Apparent prevalence of penicillin resistance was surprisingly high in human and bovine isolates. Further investigation of this phenomenon is needed and could lead to modification of standard testing and treatment recommendations in human and veterinary medicine.
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Project description:To determine differences in GC Tfh cells isolated from the tonsils of children who have undergone tonsillectomy for either recurrent Group A Streptococcus (GAS) tonsillitis (RT) or non-RT (sleep apnea). Grants: Thrasher Research Fund for an Early Career Award 12969 - Jennifer Dan UM1 AI100663 - Shane Crotty Clinical Research Fellowship Grant UK Charity No. 1089464 - David Layfield, Ramsey Cuttress, Christian Ottensmeier
2019-06-20 | GSE123977 | GEO
Project description:Proteomic analysis of GBS infected vessels isolated from CD1 mice.
2019-05-20 | MSV000083823 | MassIVE
Project description:Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large population samples and to the extensive genetic diversity between isolates, the transmission and spread of H. pylori remain poorly understood. We studied the genetic relationships of H. pylori isolated from 52 individuals of two large families living in a rural community in South Africa and from 43 individuals of 11 families living in urban settings in the United Kingdom, the United States, Korea, and Colombia. A 3,406 bp multilocus sequence haplotype was determined for a total of 142 H. pylori isolates. Isolates were assigned to biogeographic populations, and recent transmission was measured as the occurrence of non-unique isolates, i.e., isolates whose sequences were identical to those of other isolates. Members of urban families were almost always infected with isolates from the biogeographic population that is common in their location. Non-unique isolates were frequent in urban families, consistent with familial transmission between parents and children or between siblings. In contrast, the diversity of H. pylori in the South African families was much more extensive, and four distinct biogeographic populations circulated in this area. Non-unique isolates were less frequent in South African families, and there was no significant correlation between kinship and similarity of H. pylori sequences. However, individuals who lived in the same household did have an increased probability of carrying the same non-unique isolates of H. pylori, independent of kinship. We conclude that patterns of spread of H. pylori under conditions of high prevalence, such as the rural South African families, differ from those in developed countries. Horizontal transmission occurs frequently between persons who do not belong to a core family, blurring the pattern of familial transmission that is typical of developed countries. Predominantly familial transmission in urban societies is likely a result of modern living conditions with good sanitation and where physical contact between persons outside the core family is limited and regulated by societal rules. The patterns observed in rural South African families may be representative of large parts of the developing world.
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Project description:Streptococcus pyogenes (group A Streptococcus [GAS]) is a human pathogen responsible for a wide range of diseases. Asymptomatic carriage of GAS in the human pharynx is commonplace and a potential reservoir for GAS transmission. Early studies showed that GAS transmission correlated with high bacterial burdens during the acute symptomatic phase of the disease. Human studies and the nonhuman primate model are generally impractical for investigation of the bacterial mechanisms contributing to GAS transmission and persistence. To address this gap, we adapted an infant mouse model of pneumococcal colonization and transmission to investigate factors that influence GAS transmission and persistence. The model recapitulated the direct correlation between GAS burden and transmission during the acute phase of infection observed in humans and nonhuman primates. Furthermore, our results indicate that the ratio of colonized to uncolonized hosts influences the rates of GAS transmission and persistence. We used the model to test the hypothesis that capsule production influences GAS transmission and persistence in a strain-dependent manner. We detected significant differences in rates of transmission and persistence between capsule-positive (emm3) and capsule-negative (emm87) GAS strains. Capsule was associated with higher levels of GAS shedding, independent of the strain background. In contrast to the capsule-positive emm3 strain, restoring capsule production in emm87 GAS did not increase transmissibility, and the absence of capsule enhanced persistence only in the capsule-negative (emm87) strain background. These data suggest that strain background (capsule positive versus capsule negative) influences the effect of capsule in GAS transmission and persistence and that as-yet-undefined factors are required for the transmission of capsule-negative emm types.
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Project description:GBS infection in the placenta modules host innate inflammatory response
2022-02-18 | GSE196825 | GEO
Project description:We compared differential gene expression in ST399/EMM-77, invasive ST28/EMM-1 and non-invasive ST28/EMM-1, 4 isolates in each group.
2024-02-02 | GSE246380 | GEO
Project description:Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies.
| S-EPMC4162386 | biostudies-literature
Project description:OBJECTIVE:There is substantial evidence of a link between parental substance use disorders and antisocial behavior and childhood disruptive disorders in offspring, but it is unclear whether this transmission is specific to particular disorders or if a general liability accounts for familial resemblance. The authors examined whether the association between parental externalizing disorders and childhood disruptive disorders in preadolescent offspring is a result of the transmission of general or disorder-specific liabilities and estimated the genetic and environmental contributions to variation in these general and specific liability indicators. METHOD:Participants were 1,069 families consisting of 11-year-old twins and their biological mother and father. Structural equation modeling was used to simultaneously estimate the general and specific transmission effects of four parental externalizing disorders (conduct disorder, adult antisocial behavior, alcohol dependence, and drug dependence) on childhood disruptive disorders (attention deficit hyperactivity disorder, conduct disorder, and oppositional defiant disorder). RESULTS:Parent-child resemblance was accounted for by the transmission of a general liability to externalizing disorders, and this general liability was highly heritable. Specific effects were also detected, but for sibling rather than parental transmission. Specific genetic and nonshared environmental effects were detected for each childhood disruptive disorder, but only conduct disorder exhibited a significant shared environmental effect. CONCLUSIONS:A highly heritable general liability accounts for the parent-child transmission of externalizing psychopathology from parents to their preadolescent offspring. This general liability should be a focus of research for both etiology and intervention.
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Project description:Streptococcus pyogenes transmission study
| PRJEB2104 | ENA