scholarly journals Intracellular Burkholderia Symbionts Induce Extracellular Secondary Infections; Driving Diverse Host Outcomes that Vary by Genotype and Environment

2018 ◽  
Author(s):  
Niloufar Khojandi ◽  
Tamara S. Haselkorn ◽  
Madison N. Eschbach ◽  
Rana A. Naser ◽  
Susanne DiSalvo
Keyword(s):  
Dictyostelium Discoideum ◽  
Food Source ◽  
Secondary Infection ◽  
Host Fitness ◽  
Symbiotic Associations ◽  
Secondary Infections ◽  
Soil Amoeba ◽  
Food Bacteria

AbstractSymbiotic associations impact and are impacted by their surrounding ecosystem. The association between Burkholderia bacteria and the soil amoeba Dictyostelium discoideum is a tractable model to unravel the biology underlying symbiont-endowed phenotypes and their impacts. Several Burkholderia species stably associate with D. discoideum and typically reduce host fitness in food-rich environments while increasing fitness in food-scarce environments. Burkholderia symbionts are themselves inedible to their hosts but induce co-infections with secondary bacteria that can serve as a food source. Thus, Burkholderia hosts are “farmers” that carry food bacteria to new environments, providing a benefit when food is scarce. We examined the ability of specific Burkholderia genotypes to induce secondary co-infections and assessed host fitness under a range of co-infection conditions and environmental contexts. Although all Burkholderia symbionts intracellularly infected Dictyostelium, we found that co-infections are predominantly extracellular, suggesting that farming benefits are derived from extracellular infection of host structures. Furthermore, levels of secondary infection are linked to conditional host fitness; B. agricolaris infected hosts have the highest level of co-infection and have the highest fitness in food scarce environments. This study illuminates the phenomenon of co-infection induction across Dictyostelium associated Burkholderia species and exemplifies the contextual complexity of these associations.

scholarly journals Microbe Profile: Dictyostelium discoideum: model system for development, chemotaxis and biomedical research

Microbiology ◽  
2021 ◽  
Author(s):  
Catherine J. Pears ◽  
Julian D. Gross
Keyword(s):  
Pattern Formation ◽  
Cell Motility ◽  
Dictyostelium Discoideum ◽  
Biomedical Research ◽  
Model System ◽  
Developmental Pattern ◽  
Social Amoeba ◽  
The Social ◽  
Host Pathogen ◽  
Soil Amoeba

The social amoeba Dictyostelium discoideum is a versatile organism that is unusual in alternating between single-celled and multi-celled forms. It possesses highly-developed systems for cell motility and chemotaxis, phagocytosis, and developmental pattern formation. As a soil amoeba growing on microorganisms, it is exposed to many potential pathogens; it thus provides fruitful ways of investigating host-pathogen interactions and is emerging as an influential model for biomedical research.

scholarly journals ORAL SECONDARY INFECTION IN STEVENS-JOHNSON SYNDROME PATIENT WITH ORAL INVOLVEMENT: A CASE REPORT

2021 ◽  
Vol 6 (1) ◽  
pp. 79
Author(s):  
Etis Duhita Rahayuningtyas ◽  
Indah Suasani Wahyuni ◽  
Irna Sufiawati
Keyword(s):  
Case Report ◽  
Secondary Infection ◽  
Severity Of Illness ◽  
The Body ◽  
Stevens Johnson Syndrome ◽  
High Dose ◽  
Oral Manifestation ◽  
Secondary Infections ◽  
Johnson Syndrome ◽  
Oral Involvement

ABSTRACTBackground: Stevens-Johnson syndrome (SSJ) is a hypersensitivity reaction that is often triggered by drugs but this case is rare. These reactions result in uncontrolled keratinocyte damage to the skin and mucosa throughout the body, including the oral mucosa, and are often life-threatening. The use of high doses of corticosteroids is a treatment that is often given but it can trigger secondary infections of fungal and viral in the oral cavity. Purpose: This case report discusses the management of oral manifestations and secondary infections in SSJ patients, and becomes guidance for health professionals. Case: A-42-years-old male patient was consulted from the Department of Dermatology and Venereology (DV) due to oral pain and eating difficulties. The severity-of-illness-score for toxic-epidermal-necrolysis (SCORTEN) was 1. Erosive serosanguinous crusts, tend to bleed were found on the lips. Intraoral clinically presented wide erosive lesions and multiple ulcers, accompanied by a pseudomembranous plaque, and teeth decay. Hematologic examination showed an increase in leukocytes, neutrophil segments, monocytes, SGOT, urea, and creatinine as well as decreased hemoglobin, hematocrit, erythrocytes, MCHC, protein, and albumin. Anti-HSV1 IgG increased almost 6 times than normal values. The patient was diagnosed with SJS with oral involvement, secondary infections of pseudomembranous candidiasis, and herpetic stomatitis. Case Management: Systemic therapy given were intravenous dexamethasone, ranitidine, calcium, and cetirizine, from the DV Department, while hydrocortisone lip ointment, Chlorhexidine digluconate 0.12%, and Nystatin oral suspension for oral problems. The lesions progressed in 24 days. Conclusion: Oral secondary infections may occur in SJS patients due to high-dose corticosteroid therapy.Keywords: Herpetic Stomatitis, Oral Manifestation, Oral Secondary Infection, Pseudomembranous Candidiasis, Stevens-Johnson Syndrome.

scholarly journals Estimating and interpreting secondary attack risk: Binomial considered biased

2021 ◽  
Vol 17 (1) ◽  
pp. e1008601
Author(s):  
Yushuf Sharker ◽  
Eben Kenah
Keyword(s):  
Los Angeles ◽  
Influenza A ◽  
Secondary Infection ◽  
Random Variable ◽  
Household Member ◽  
Primary Case ◽  
Multiple Generations ◽  
Secondary Infections ◽  
Influenza A H1n1 ◽  
Binomial Models

The household secondary attack risk (SAR), often called the secondary attack rate or secondary infection risk, is the probability of infectious contact from an infectious household member A to a given household member B, where we define infectious contact to be a contact sufficient to infect B if he or she is susceptible. Estimation of the SAR is an important part of understanding and controlling the transmission of infectious diseases. In practice, it is most often estimated using binomial models such as logistic regression, which implicitly attribute all secondary infections in a household to the primary case. In the simplest case, the number of secondary infections in a household with m susceptibles and a single primary case is modeled as a binomial(m, p) random variable where p is the SAR. Although it has long been understood that transmission within households is not binomial, it is thought that multiple generations of transmission can be neglected safely when p is small. We use probability generating functions and simulations to show that this is a mistake. The proportion of susceptible household members infected can be substantially larger than the SAR even when p is small. As a result, binomial estimates of the SAR are biased upward and their confidence intervals have poor coverage probabilities even if adjusted for clustering. Accurate point and interval estimates of the SAR can be obtained using longitudinal chain binomial models or pairwise survival analysis, which account for multiple generations of transmission within households, the ongoing risk of infection from outside the household, and incomplete follow-up. We illustrate the practical implications of these results in an analysis of household surveillance data collected by the Los Angeles County Department of Public Health during the 2009 influenza A (H1N1) pandemic.

Abstract 17113: Secondary Infections Are Common in Patients Hospitalized for COVID-19 and Are Associated With Severe Outcomes

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Elizabeth R Anderson ◽  
Tariq Azam ◽  
Husam Shadid ◽  
Michael Pan ◽  
Hanna Berlin ◽  
...  
Keyword(s):  
Prospective Observational Study ◽  
Viral Infections ◽  
Clinical Laboratory ◽  
Secondary Infection ◽  
Kidney Injury ◽  
Outcome Data ◽  
Hospitalized Patients ◽  
Secondary Infections ◽  
Life Threatening ◽  
The Mean

Background: Secondary infections occur in 10-15% of critically ill sepsis patients. Anecdotal reports suggest secondary infections are common in coronavirus disease 2019 (COVID-19), however data are lacking. We examine the rate of secondary infections in hospitalized patients with COVID-19 and its impact on the cytokine surge and in-hospital outcomes. Methods: The Michigan Medicine Covid-19 Cohort (M2C2) is an ongoing prospective observational study in which detailed clinical, laboratory and outcome data were collected from chart review of consecutive adult patients hospitalized for COVID-19. Patients who were positive for SARS-CoV-2 infection but without respiratory symptoms were not included in this cohort. We define secondary infections as physician-diagnosed and treated bacterial or viral infections secondary to SARS-CoV-2. Results: Of 553 COVID-19 patients hospitalized at Michigan Medicine, 191 (34.5%) developed a secondary infection during hospitalization. The mean age of patients with a secondary infection was 60 years, 61.3% were male compared to 58.8 years, 53.5% male in patients with no secondary infection. Bacterial pneumonia, including ventilator-associated pneumonia, was the most prevalent secondary infection among hospitalized patients (78.5%). Other secondary infections included urosepsis (14.1%), bacteremia (16.8%), and 17.3% of patients developed other types of infections such as shingles and clostridium difficile. 25.8% of patients without secondary infections received antibiotics during their admission compared to 47.1% of patients with secondary infections. Multiple secondary infections (>1) occurred in 43 (8.2%) of patients. Patients with secondary infections were more likely to develop acute kidney injury (78.0% vs. 38.3%, p<0.0001), acute respiratory distress syndrome (78.0% vs. 22.3%, p<0.0001), and death (26.2% vs. 10.2%, p<0.0001) during their hospitalization compared to patients without secondary infections. Conclusions: Secondary infections are common in hospitalized patients with COVID-19 and are associated with life-threatening complications and high mortality. This study suggests that secondary infection prevention may be especially important in COVID-19 patients.

scholarly journals Titer regulation in arthropod-Wolbachia symbioses

2019 ◽  
Vol 366 (23) ◽  
Author(s):  
Sergio López-Madrigal ◽  
Elves H Duarte
Keyword(s):  
Wolbachia Infection ◽  
Intracellular Bacteria ◽  
Biological Factors ◽  
Wolbachia Pipientis ◽  
Host Fitness ◽  
Symbiotic Associations ◽  
Infection Dynamics ◽  
Wide Range ◽  
High Prevalence ◽  
Fine Regulation

ABSTRACT Symbiosis between intracellular bacteria (endosymbionts) and animals are widespread. The alphaproteobacterium Wolbachia pipientis is known to maintain a variety of symbiotic associations, ranging from mutualism to parasitism, with a wide range of invertebrates. Wolbachia infection might deeply affect host fitness (e.g. reproductive manipulation and antiviral protection), which is thought to explain its high prevalence in nature. Bacterial loads significantly influence both the infection dynamics and the extent of bacteria-induced host phenotypes. Hence, fine regulation of bacterial titers is considered as a milestone in host-endosymbiont interplay. Here, we review both environmental and biological factors modulating Wolbachia titers in arthropods.

Hymenolepis diminuta: changes in intestinal morphology and the enterochromaffin cell population associated with infection in male C57 mice

Parasitology ◽  
1990 ◽  
Vol 101 (1) ◽  
pp. 107-113 ◽  
Author(s):  
D. M. Mckay ◽  
D. W. Halton ◽  
C. F. Johnston ◽  
I. Fairweather ◽  
C. Shaw
Keyword(s):  
Secondary Infection ◽  
Intestinal Morphology ◽  
Hymenolepis Diminuta ◽  
Enterochromaffin Cell ◽  
Villus Height ◽  
Post Secondary ◽  
Crypt Depth ◽  
Secondary Infections ◽  
Ec Cells ◽  
Mucosal Surface Area

SUMMARYMean villus height, crypt depth and the number of 5-HT-positive enterochromaffin (EC) cells have been examined in two regions of the small intestine (20–30° and 60–70° distance from the pylorus) of male, 6 to 8-week-old, C57 mice following a 5-cysticercoid infection of the rat tapeworm, Hymenolepis diminuta. Test mice and sham-infected controls were autopsied 0, 4, 8, 10, 14 and 28 days post-primary infection (p-1°-i) and 2, 4, 5, 7 and 14 days post-secondary infection (p-2°-i), administered 28 days p-1°-i. Morphometric analysis revealed a statistically significant increase in crypt depth in the 60–70°o intestine region in infected mice during both primary and secondary infections; no significant deviation from the control was observed for villus height in infected mice. Statistical analysis showed a significant increase in the number of 5-HT-positive EC cells in infected mice. This response occurred in the lower portion of the intestine on days 10-p-1°-i and 5-p-2°-i, and was not due to increased mucosal surface area in this region. Results are discussed with reference to murine cestode rejection and the possible involvement therein of the neuroendocrine system.

Etomidate Use for Rapid Sequence Intubation Is Not Associated With Nosocomial Infection

2020 ◽  
pp. 089719002097961
Author(s):  
Daniel Colon Hidalgo ◽  
Vishali Amin ◽  
Arushi Hukku ◽  
Kathryn Kutlu ◽  
Megan A. Rech
Keyword(s):  
Hospital Stay ◽  
Secondary Infection ◽  
Length Of Hospital Stay ◽  
Adrenal Suppression ◽  
Rapid Sequence Intubation ◽  
Control Group ◽  
Secondary Infections ◽  
Rapid Sequence ◽  
Significant Difference ◽  
Secondary Outcomes

Introduction: Etomidate is commonly used for induction of anesthesia for rapid sequence intubation (RSI). It has little impact on hemodynamic status, making it a widely used agent. Due to the inhibition of cortisol production, etomidate causes adrenal suppression. The purpose of this study is to determine whether there is a correlation with etomidate use and the incidence of secondary infections. Methods: This was a retrospective cohort of hospitalized patients who received either etomidate or control (ketamine, propofol, or no agent) for RSI. The primary endpoint was the incidence of secondary infections. Secondary outcomes included number of mechanical ventilator-free days within 28 days, 30-day mortality, length of hospital stay, and length of intensive care unit stay. Results: A total of 434 patients were reviewed, of which 129 (29.7%) met the study criteria (n = 94 etomidate; n = 35 control). The incidence of secondary infection was numerically higher in the etomidate group compared with the control group, though this was not statistically significant (38.7% vs. 28.6%, p = 0.447). Also, though the secondary outcomes showed no statistically significant difference between the groups, the patients in the control group had a longer hospital stay (14.0 vs. 18.1, p = 0.20) and a longer ICU stay (11.0 vs. 14.1, p = 030). Furthermore, the etomidate group had a non-statistically significant higher incidence of bacteremia (8 vs. 0, p = 0.17) Conclusion: The use of etomidate was not associated with increased incidence of secondary infection. To fully understand the effects of etomidate use and its subsequent adrenal suppression, larger studies are needed.

Nutrition support and the human immunodeficiency virus (HIV)

Parasitology ◽  
1993 ◽  
Vol 107 (S1) ◽  
pp. S53-S67 ◽  
Author(s):  
S. J. Bell ◽  
E. A. Mascioli ◽  
R. A. Forse ◽  
B. R. Bistrian
Keyword(s):  
Dietary Supplements ◽  
Nutritional Support ◽  
Secondary Infection ◽  
Rapid Development ◽  
Latency Period ◽  
Nutrient Utilization ◽  
Nutrition Support ◽  
Trauma Patients ◽  
Hiv Patients ◽  
Secondary Infections

SUMMARYNutritional support of patients with HIV or acquired immune deficiency syndrome (AIDS) has many similarities to other disease states in that the same nutritional products and techniques are used. Some patients with HIV, and many with AIDS without secondary infection, experience a metabolic milieu similar to patients with cancer cachexia. In providing dietary counselling to the HIV patient, we encounter many of the obstacles that must be overcome to improve nutrition in cancer: anorexia, gastrointestinal discomfort, lethargy, and poor nutrient utilization, which limit the ability for nutritional repletion. When a secondary infection is superimposed on HIV, patients resemble more highly catabolic trauma patients or patients in the intensive care unit (ICU), where, despite aggressive efforts to feed, there is usually a net nitrogen wasting leading to the more rapid development of cachexia. However, even in this setting, feeding will limit substantially net catabolism when compared to total starvation. Because the nutritional needs of HIV patients vary greatly, individual strategies have to be designed as the patient moves through the stages of disease. Patients are generally able to consume adequate nutrition either as regular food or dietary supplements during the latency period of viral replication. Once secondary infections become prevalent, artificial diets administered by tube or by vein may be required during the period of active secondary infections, with dietary supplements often helpful during more quiescent periods. Patients with HIV are among the most challenging for clinicians providing nutritional support. Knowledge from treatment of patients with other diseases may be useful, but more data must be gathered on the unique aspects of aetiology and treatment of the anorexia, malabsorption, and ultimate wasting associated with AIDS.

scholarly journals Estimation of Dengue Virus IgM Persistence Using Regression Analysis

2011 ◽  
Vol 18 (12) ◽  
pp. 2183-2185 ◽  
Author(s):  
Harry E. Prince ◽  
Jose L. Matud
Keyword(s):  
Regression Analysis ◽  
Dengue Virus ◽  
Primary Infection ◽  
Secondary Infection ◽  
Disease Onset ◽  
Decay Rates ◽  
Point Index ◽  
Infection Group ◽  
Secondary Infections

ABSTRACTDengue virus IgM persistence was estimated using follow-up sera from 98 patients (60 with primary infections and 38 with secondary infections) whose first-specimen IgM index was strongly positive, suggesting recent disease onset. Regression analysis of the follow-up IgM index versus days between samples yielded a trend line that reached the cut-point index (1.10) at 179 days for the primary infection group and 139 days for the secondary infection group. This difference reflected significantly higher first-sample IgM indices in primary infections than in secondary infections rather than differences in IgM decay rates.

scholarly journals “Endomicrobia” and Other Bacteria Associated with the Hindgut of Dermolepida albohirtum Larvae

2007 ◽  
Vol 74 (3) ◽  
pp. 762-767 ◽  
Author(s):  
Geoffrey W. Pittman ◽  
Stevens M. Brumbley ◽  
Peter G. Allsopp ◽  
Scott L. O'Neill
Keyword(s):  
Gel Electrophoresis ◽  
Food Source ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Plant Root ◽  
Agricultural Crops ◽  
Symbiotic Associations ◽  
Gradient Gel Electrophoresis ◽  
Feeding Activities ◽  
Geographic Regions ◽  
Root Feeding

ABSTRACT Symbiotic bacteria residing in the hindgut chambers of scarab beetle larvae may be useful in paratransgenic approaches to reduce larval root-feeding activities on agricultural crops. We compared the bacterial community profiles associated with the hindgut walls of individual Dermolepida albohirtum third-instar larvae over 2 years and those associated with their plant root food source among different geographic regions. Denaturing gradient gel electrophoresis analysis was used with universal and Actinobacteria-specific 16S rRNA primers to reveal a number of taxa that were found consistently in all D. albohirtum larvae but not in samples from their food source, sugarcane roots. These taxa included representatives from the “Endomicrobia,” Firmicutes, Proteobacteria, and Actinobacteria and were related to previously described bacteria from the intestines of other scarab larvae and termites. These universally distributed taxa have the potential to form vertically transmitted symbiotic associations with these insects.

Sign in / Sign up

Export Citation Format

Share Document