Fever as an important resource for infectious diseases research

Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo

BACKGROUND

Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39 °C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37 °C, by using RNAseq and physiological assays including in vivo experiments.

RESULTS

In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes in both species. Altered metabolic features at 39 °C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39 °C, they upregulated ethanol oxidation-related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα, and pmsβ genes at 39 °C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphyloxantin production, and a decrease in biofilm formation at 39 °C. On the side of PA monocultures, we observed an increase in extracellular lipase and protease and biofilm formation at 39 °C along with a decrease in the motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in vitro and in vivo. S. aureus monocultured at 39οC showed a decrease in cellular invasion and an increase in IL-8-but not in IL-6-production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39 °C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37 and 39 °C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39 °C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39 °C comparing with 37 °C.

CONCLUSIONS

Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

Machine learning-based clinical decision support for infection risk prediction

Background

Healthcare-associated infection (HAI) remains a significant risk for hospitalized patients and a challenging burden for the healthcare system. This study presents a clinical decision support tool that can be used in clinical workflows to proactively engage secondary assessments of pre-symptomatic and at-risk infection patients, thereby enabling earlier diagnosis and treatment.

Methods

This study applies machine learning, specifically ensemble-based boosted decision trees, on large retrospective hospital datasets to develop an infection risk score that predicts infection before obvious symptoms present. We extracted a stratified machine learning dataset of 36,782 healthcare-associated infection patients. The model leveraged vital signs, laboratory measurements and demographics to predict HAI before clinical suspicion, defined as the order of a microbiology test or administration of antibiotics.

Results

Our best performing infection risk model achieves a cross-validated AUC of 0.88 at 1 h before clinical suspicion and maintains an AUC >0.85 for 48 h before suspicion by aggregating information across demographics and a set of 163 vital signs and laboratory measurements. A second model trained on a reduced feature space comprising demographics and the 36 most frequently measured vital signs and laboratory measurements can still achieve an AUC of 0.86 at 1 h before clinical suspicion. These results compare favorably against using temperature alone and clinical rules such as the quick sequential organ failure assessment (qSOFA) score. Along with the performance results, we also provide an analysis of model interpretability via feature importance rankings.

Conclusion

The predictive model aggregates information from multiple physiological parameters such as vital signs and laboratory measurements to provide a continuous risk score of infection that can be deployed in hospitals to provide advance warning of patient deterioration.

Current State of Knowledge on the Definition, Pathophysiology, Etiology, Outcomes, and Management of Fever in the Intensive Care Unit

Fever-an elevated body temperature-is a prominent feature of a wide range of disease conditions and is a common finding in intensive care, affecting up to 70% of patients in the intensive care unit (ICU). The causes of fever in the ICU are multifactorial, and it can be due to a number of infective and noninfective etiologies. The production of fever represents a complex physiological, adaptive host response that is beneficial for host defense and survival but can be maladaptive and harmful if left unabated. Despite any cause, fever is associated with a wide range of cellular, local, and systemic effects, including multiorgan dysfunction, systemic inflammation, poor neurological recovery, and an increased risk of mortality. This narrative review presents the current state-of-the-art knowledge on the definition, pathophysiology, etiology, and outcomes of fever in the ICU and highlights evidence-based findings regarding the management of fever in the intensive care setting.

The Association Between Malignant Otitis Externa and Diabetes Mellitus in Africa: A Systematic Review

Diabetes mellitus is one of the risk factors for malignant otitis externa. There are very few studies on the disease in Africa and there is a need to pool the prior studies to highlight the characteristics of the disease. The study type is a systematic review and the PRISMA guidelines were followed. Using the appropriate terms, relevant medical databases were systematically searched. Thirty-two studies met the eligibility criteria with a total sample size of 848, who were mainly elderly. Diabetes mellitus was present in 94% of the participants. Average duration of diabetes diagnosis in the participants was 12.4 years. The pooled HbA1c was 9.8%. The most common symptoms were otalgia (96.1%), otorrhoea (75.8%) and hearing loss (56.1%). Pseudomonas was the most common isolate (72%). Fluoroquinolones and the 3rd-generation cephalosporins were the preferred antibiotics. The pooled cure rate from antimicrobial usage was 76.2%. In addition to medications, 24.6% of the affected individuals required debridement. About 1.6% of the participants died from malignant otitis externa. Malignant otitis externa is associated with poorly controlled diabetes. Pseudomonas is the most common cause and a significant proportion gets cured with prolonged antibiotherapy.

Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo

Background

Staphylococcus aureus and Pseudomonas aeruginosa cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39°C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37°C, by using RNAseq and physiological assays including in-vivo experiments.

Results

In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes on both species. Altered metabolic features at 39°C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39°C they upregulated ethanol oxidation related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα and pmsβ genes at 39°C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphylxantin production and a decrease in biofilm formation at 39°C. On the side of PA monocultures, we observed increase in extracellular lipase and protease and biofilm formation at 39°C along with a decrease in motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in-vitro and in-vivo . S. aureus monocultured at 39°C showed a decrease in cellular invasion and an increase in IL-8 -but not in IL-6- production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39°C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37°C and 39°C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39°C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39°C comparing with 37°C.

Conclusion

Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

Anemia and associated factors among internally displaced children at Debark refugee camp, North Gondar, Northwest Ethiopia

BACKGROUND

Children in refugee camps, due to their living conditions, are the most vulnerable groups to suffer from anemia. Nutritional deficiencies, especially iron deficiency is the most common causes of anemia. However, there is limited information on the prevalence and associated factors of anemia in Ethiopia. Hence, this study aimed to assess the prevalence and associated factors of anemia among internally displaced children at Debark refugee camp, Northwest Ethiopia.

METHODS

A cross-sectional study was conducted on 354 internally displaced children, at Debark refugee camp from March to May 2022. A systematic sampling technique was employed. The socio demographic characteristics were collected by using structured questionnaire via face-to-face interview with the caregivers. The hemoglobin level was determined using HemoCue301+. Form anemic children, venous blood sample was collected for iron profile analysis. Parasitological and anthropometric measurements were also done. The data were entered using Epi-data version 4.6.0.6 and exported to STATA version 14 for analysis. Bi-variable and multivariable binary logistic regression analysis were done. Both crude odds ratio and adjusted odds ratio with the corresponding 95% confidence interval were calculated to measure the strength of association. P-Value < 0.05 was considered as statistically significant association.

RESULTS

From the total of 354 children included in this study, more than half (54.8%) of them were male. The median age of children was 7 years with interquartile range of (4-10) years. The total prevalence of anemia in this study was 33.62% (95% CI:28.7, 38.7). Moderate type anemia was predominant in this study. From anemic children 30 (25.2%) had iron deficiency anemia. In this study, low dietary diversity (AOR = 4.9; 95% CI: 2.0, 11.7), duration in the camp more than six months (AOR = 4.2; 95% CI:1.9, 9.4), presence of diarrhea (AOR = 2.7; 95% CI:1.3, 5.7), fever (AOR = 3.4; 95% CI:1.6, 7.1), and wasting (AOR = 3.6; 95% CI:1.3, 10.3) were significantly associated with the prevalence of anemia.

CONCLUSION

Anemia was moderate public health problem in the current study. Focused policies and strategies towards to internally displaced children should be designed to reduce anemia, by preventing the significant risk factors associated with anemia.

Role of nickel-regulated small RNA in modulation of Helicobacter pylori virulence factors

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects about half of the world's population. H. pylori infection prevails by several mechanisms of adaptation of the bacteria and by its virulence factors including the cytotoxin associated antigen A (CagA). CagA is an oncoprotein that is the protagonist of gastric carcinogenesis associated with prolonged H. pylori infection. In this sense, small regulatory RNAs (sRNAs) are important macromolecules capable of inhibiting and activating gene expression. This function allows sRNAs to act in adjusting to unstable environmental conditions and in responding to cellular stresses in bacterial infections. Recent discoveries have shown that nickel-regulated small RNA (NikS) is a post-transcriptional regulator of virulence properties of H. pylori, including the oncoprotein CagA. Notably, high concentrations of nickel cause the reduction of NikS expression and consequently this increases the levels of CagA. In addition, NikS expression appears to be lower in clinical isolates from patients with gastric cancer when compared to patients without. With that in mind, this minireview approaches, in an accessible way, the most important and current aspects about the role of NikS in the control of virulence factors of H. pylori and the potential clinical repercussions of this modulation.

Harnessing genetic resistance to rusts in wheat and integrated rust management methods to develop more durable resistant cultivars

Wheat is one of the most important staple foods on earth. Leaf rust, stem rust and stripe rust, caused by Puccini triticina, Puccinia f. sp. graminis and Puccinia f. sp. striiformis, respectively, continue to threaten wheat production worldwide. Utilization of resistant cultivars is the most effective and chemical-free strategy to control rust diseases. Convectional and molecular biology techniques identified more than 200 resistance genes and their associated markers from common wheat and wheat wild relatives, which can be used by breeders in resistance breeding programmes. However, there is continuous emergence of new races of rust pathogens with novel degrees of virulence, thus rendering wheat resistance genes ineffective. An integration of genomic selection, genome editing, molecular breeding and marker-assisted selection, and phenotypic evaluations is required in developing high quality wheat varieties with resistance to multiple pathogens. Although host genotype resistance and application of fungicides are the most generally utilized approaches for controlling wheat rusts, effective agronomic methods are required to reduce disease management costs and increase wheat production sustainability. This review gives a critical overview of the current knowledge of rust resistance, particularly race-specific and non-race specific resistance, the role of pathogenesis-related proteins, non-coding RNAs, and transcription factors in rust resistance, and the molecular basis of interactions between wheat and rust pathogens. It will also discuss the new advances on how integrated rust management methods can assist in developing more durable resistant cultivars in these pathosystems.

The Relationship Between Colles’ Fractures and Leukocytosis in the Emergency Department

In Taiwan, emergency physicians often perform wrist joint reduction and cast immobilization before orthopedic surgeons arrange for surgical management. Prophylactic antibiotics can decrease the risk of wound infection and have been routinely employed in orthopedic surgery. In Taiwan, emergency physicians also regularly perform blood investigations and administer prophylactic antibiotics to prevent infection if the patient exhibits leukocytosis. However, pain and pressure also cause leukocytosis, making it difficult to discern if the cause is infection or injury. Therefore, we explored the relationship between Colles’ fractures and leukocytosis to determine if antibiotic treatment is necessary for this type of injury.

Are all thermometers equal? A study of three infrared thermometers to detect fever in an African outpatient clinic

Infrared thermometry has certain advantages over traditional oral thermometry including quick, non-invasive administration and an absence of required consumables. This study compared the performance of tympanic, temporal artery and forehead contactless thermometers with traditional oral electronic thermometer as the reference in measuring temperature in outpatients in a Nigerian secondary care hospital. A convenience sample of 100 male and 100 female adult patients (Mean age = 38.46 years, SD = 16.33 years) were recruited from a secondary care hospital in Kano, Nigeria. Temperature measurements were taken from each patient using the tympanic, temporal artery and contactless thermometers and oral electronic thermometer. Data was analyzed to assess bias and limits using scatterplots and Bland-Altman charts while sensitivity analysis was done using ROC curves. The tympanic and temporal artery thermometers systematically gave higher temperature readings compared to the oral electronic thermometer. The contactless thermometer gave lower readings compared to the oral electronic thermometer. The temporal artery thermometer had the highest sensitivity (88%) and specificity (88%) among the three infrared thermometers. The contactless thermometer showed a low sensitivity of 13% to detect fever greater than 38 °C. Our study shows that replacing oral thermometers with infrared thermometers must be done with caution despite the associated convenience and cost savings.

Genetic background influences survival of infections with Salmonella enterica serovar Typhimurium in the Collaborative Cross

Salmonella infections typically cause self-limiting gastroenteritis, but in some individuals these bacteria can spread systemically and cause disseminated disease. Salmonella Typhimurium (STm), which causes severe systemic disease in most inbred mice, has been used as a model for disseminated disease. To screen for new infection phenotypes across a range of host genetics, we orally infected 32 Collaborative Cross (CC) mouse strains with STm and monitored their disease progression for seven days by telemetry. Our data revealed a broad range of phenotypes across CC strains in many parameters including survival, bacterial colonization, tissue damage, complete blood counts (CBC), and serum cytokines. Eighteen CC strains survived to day 7, while fourteen susceptible strains succumbed to infection before day 7. Several CC strains had sex differences in survival and colonization. Surviving strains had lower pre-infection baseline temperatures and were less active during their daily active period. Core body temperature disruptions were detected earlier after STm infection than activity disruptions, making temperature a better detector of illness. All CC strains had STm in spleen and liver, but susceptible strains were more highly colonized. Tissue damage was weakly negatively correlated to survival. We identified loci associated with survival on Chromosomes (Chr) 1, 2, 4, 7. Polymorphisms in Ncf2 and Slc11a1, known to reduce survival in mice after STm infections, are located in the Chr 1 interval, and the Chr 7 association overlaps with a previously identified QTL peak called Ses2. We identified two new genetic regions on Chr 2 and 4 associated with susceptibility to STm infection. Our data reveal the diversity of responses to STm infection across a range of host genetics and identified new candidate regions for survival of STm infection.

Evaluation of reticulorumen temperature boluses for the diagnosis of subclinical cases of bovine respiratory disease in feedlot cattle

Bovine respiratory disease (BRD) is the most important and costly health issue of the feedlot industry worldwide. Remote monitoring of reticulorumen temperature has been suggested as a potential tool to improve the diagnostic accuracy of BRD. The present study aimed to evaluate 1) the difference and degree of reticulorumen hyperthermia episodes between healthy and subclinical BRD feedlot steers, and 2) determine the correlation between reticulorumen hyperthermia and lung pathology, performance, and carcass traits. Mixed-breed feedlot steers (n = 148) with a mean arrival weight of 321 ± 3.34 kg were administered a reticulorumen bolus at feedlot entry and monitored for visual and audible signs of BRD until slaughter when lungs were examined and scored for lesions indicative of BRD. Post-slaughter animals with no record of BRD treatment were assigned to one of three case definitions. Healthy steers had no visual or audible signs of BRD (i.e., CIS=1), and total lung consolidation score < 5% or pleurisy score < 3 at slaughter. Subclinical BRD cases had a CIS of 1, and a lung consolidation score ≥ 5% or a pleurisy score of 3 at slaughter. Mild CIS cases had at least one CIS of 2, and a lung consolidation score < 5% and a pleurisy score < 3 at slaughter. Subclinical BRD and mild CIS cases had longer total duration of reticulorumen hyperthermia, more episodes and longer average episode duration above 40.0 °C compared to healthy steers (P < 0.05). A moderate positive correlation was found between lung consolidation and total duration (r = 0.27, P < 0.001), episode duration (r = 0.29, P < 0.001), and number of episodes (r = 0.20, P < 0.05). Pleurisy score was also found to be moderately and positively correlated with total duration (r = 0.23, P < 0.01), episode duration (r = 0.37, P < 0.001), and number of episodes (r = 0.26, P < 0.01). Moderate negative correlations were found between reticulorumen hyperthermia and carcass traits including hot standard carcass weight (HSCW) (-0.22 ≤ r ≤ -0.23, P < 0.05) and P8-fat depth (-0.18 ≤ r ≤ -0.32, P < 0.05). Subclinical BRD reduced carcass weight by 22 kg and average daily gain (ADG) by 0.44 kg/day compared to healthy steers (P < 0.05), but mild CIS cases had no effect on performance (P > 0.05). The reticulorumen bolus technology appears promising for detection of subclinical BRD cases in feedlot cattle as defined by lung pathology at slaughter.

Cross-sectional study of parental knowledge, behaviour and anxiety in management of paediatric fever among German parents

OBJECTIVES

Fever is a common symptom among children. Parental lack of knowledge about fever could cause anxiety and lead to unnecessary measures to subside fever. There is little evidence about German parents' knowledge and their fever management.

DESIGN

A cross-sectional study using a paper-based questionnaire.

SETTING

16 kindergartens in Saarbrücken and Saarlouis regional association accepted to participate in the study. Parents from these kindergartens were requested during the pickup time to answer the questionnaire.

PARTICIPANTS

481 German parents participated in the study, 394 of them were women. Inclusion criteria were good understanding of German and being a parent of at least one child below the age of 7 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Knowledge and behaviour of parents on paediatric fever management and the factors influencing fever anxiety.

RESULTS

The older the parents were, the more anxiety they reported. Their definition of fever had a wide range of 30°C-41°C (mean 38.46, SD=0.67) and almost 90% (mean 3.05, SD=2.03) of participants reported fever as useful, whereby they felt more confident the more they found fever useful. 69% of parents felt calm when their child has fever (mean 4.47, SD=2.27). In case of fever, 55% of parents administer paracetamol, 72% ibuprofen and 32% of them would alternate between the two. Paracetamol and ibuprofen are used more by more anxious parents. In explorative factor analysis, reasons to reduce temperature were summarised in three main factors: damage prevention, illness control and well-being protection, whereby the first two were positively related to parental anxiety.

CONCLUSIONS

Both knowledge as well as level of confidence/anxiety vary largely. Taking antipyretics is related to higher level of anxiety, indicating the need for further education. Fever anxiety depends on multiple factors, which have to be further investigated.

Perinatal Infection: A Major Contributor to Efficacy of Cooling in Newborns Following Birth Asphyxia

Neonatal encephalopathy (NE) is a global burden, as more than 90% of NE occurs in low- and middle-income countries (LMICs). Perinatal infection seems to limit the neuroprotective efficacy of therapeutic hypothermia. Efforts made to use therapeutic hypothermia in LMICs treating NE has led to increased neonatal mortality rates. The heat shock and cold shock protein responses are essential for survival against a wide range of stressors during which organisms raise their core body temperature and temporarily subject themselves to thermal and cold stress in the face of infection. The characteristic increase and decrease in core body temperature activates and utilizes elements of the heat shock and cold shock response pathways to modify cytokine and chemokine gene expression, cellular signaling, and immune cell mobilization to sites of inflammation, infection, and injury. Hypothermia stimulates microglia to secret cold-inducible RNA-binding protein (CIRP), which triggers NF-κB, controlling multiple inflammatory pathways, including nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes and cyclooxygenase-2 (COX-2) signaling. Brain responses through changes in heat shock protein and cold shock protein transcription and gene-expression following fever range and hyperthermia may be new promising potential therapeutic targets.

Let fever do its job: The meaning of fever in the pandemic era

Although fever is one of the main presenting symptoms of COVID-19 infection, little public attention has been given to fever as an evolved defense. Fever, the regulated increase in the body temperature, is part of the evolved systemic reaction to infection known as the acute phase response. The heat of fever augments the performance of immune cells, induces stress on pathogens and infected cells directly, and combines with other stressors to provide a nonspecific immune defense. Observational trials in humans suggest a survival benefit from fever, and randomized trials published before COVID-19 do not support fever reduction in patients with infection. Like public health measures that seem burdensome and excessive, fevers involve costly trade-offs but they can prevent infection from getting out of control. For infections with novel SARS-CoV-2, the precautionary principle applies: unless evidence suggests otherwise, we advise that fever should be allowed to run its course. Lay summary: For COVID-19, many public health organizations have advised treating fever with medicines such as acetaminophen or ibuprofen. Even though this is a common practice, lowering body temperature has not improved survival in laboratory animals or in patients with infections. Blocking fever can be harmful because fever, along with other sickness symptoms, evolved as a defense against infection. Fever works by causing more damage to pathogens and infected cells than it does to healthy cells in the body. During pandemic COVID-19, the benefits of allowing fever to occur probably outweigh its harms, for individuals and for the public at large.

The application of wearable smart sensors for monitoring the vital signs of patients in epidemics: a systematic literature review

Wearable smart sensors are emerging technology for daily monitoring of vital signs with the reducing discomfort and interference with normal human activities. The main objective of this study was to review the applied wearable smart sensors for disease control and vital signs monitoring in epidemics outbreaks. A comprehensive search was conducted in Web of Science, Scopus, IEEE Library, PubMed and Google Scholar databases to identify relevant studies published until June 2, 2020. Main extracted specifications for each paper are publication details, type of sensor, disease, type of monitored vital sign, function and usage. Of 277 articles, 11 studies were eligible for criteria. 36% of papers were published in 2020. Articles were published in 10 different journals and only in the Journal of Medical Systems more than one article was published. Most sensors were used to monitor body temperature, heart rate and blood pressure. Wearable devices (like a helmet, watch, or cuff) and body area network sensors were popular types which can be used monitoring vital signs for epidemic trending. 65% of total papers (n = 6) were conducted by the USA, Malaysia and India. Applying appropriate technological solutions could improve control and management of epidemic disease as well as the application of sensors for continuous monitoring of vital signs. However, further studies are needed to investigate the real effects of these sensors and their effectiveness.

Chemoresponsive polymer systems for selective molecular recognition of organic molecules in biological systems

Smart polymer materials that respond to a chemical stimulus are applied for the construction of biomedical devices and purification/separation systems. Small organic molecules are a particular type of stimulus. Their abnormal concentration indisputably indicates certain diseases. They are also hazardous environment contaminants. Polymer materials, which structure is selectively changed in the presence of a defined organic compound are promising in view of regulation of certain biomedical functions, as well as in view of chemical detectors construction. This review summarizes the state of the art in the self-assemblies of amphiphilic copolymers and polymer networks sensitive toward organic species, with an emphasis on the reports from the last decade. We focus on the relationship between the selectivity of introduced receptor moieties responsible for the change of material structure, the overall structure of material and its functionality.

Small RNAs as Fundamental Players in the Transference of Information During Bacterial Infectious Diseases

Communication shapes life on Earth. Transference of information has played a paramount role on the evolution of all living or extinct organisms since the appearance of life. Success or failure in this process will determine the prevalence or disappearance of a certain set of genes, the basis of Darwinian paradigm. Among different molecules used for transmission or reception of information, RNA plays a key role. For instance, the early precursors of life were information molecules based in primitive RNA forms. A growing field of research has focused on the contribution of small non-coding RNA forms due to its role on infectious diseases. These are short RNA species that carry out regulatory tasks in cis or trans. Small RNAs have shown their relevance in fine tuning the expression and activity of important regulators of essential genes for bacteria. Regulation of targets occurs through a plethora of mechanisms, including mRNA stabilization/destabilization, driving target mRNAs to degradation, or direct binding to regulatory proteins. Different studies have been conducted during the interplay of pathogenic bacteria with several hosts, including humans, animals, or plants. The sRNAs help the invader to quickly adapt to the change in environmental conditions when it enters in the host, or passes to a free state. The adaptation is achieved by direct targeting of the pathogen genes, or subversion of the host immune system. Pathogens trigger also an immune response in the host, which has been shown as well to be regulated by a wide range of sRNAs. This review focuses on the most recent host-pathogen interaction studies during bacterial infectious diseases, providing the perspective of the pathogen.

Ingestible sensors correlate closely with peripheral temperature measurements in febrile patients

BACKGROUNDS

Reliable non-invasive methods for measuring body temperature are essential for the diagnosis and monitoring of infectious disease.

METHODS

This study used Intraclass Correlation Coefficients (ICC) and the Bland- Altman plot to analyse the agreement between temperature measurements using an ingestible capsule sensor, a skin sensor and two non-invasive peripheral temperature measurements (axillary and infrared non-contact), collected from a population of febrile patient admitted for infectious disease.

RESULTS

Of the 77 febrile patients screened, 26 patients were enrolled. The ICC between axillary temperature measurements (Taxi) vs. non-contact measurements (Tno-c) were 0.34 [-0.18; 0.63], 0.87 [0.55; 0.94] between Taxi vs. ingestible capsule measurements (Tcap) and 0.12 [-0.09; 0.37] between Taxi vs. Tetac. The mean difference between Taxi vs Tno-c was -1.18 °C with limits of agreement (LoA) from -2.96 to 0.58 °C. The mean difference between Taxi vs Tcap was 0.48 °C, with LoA from -0.60 to 1.56 °C. The mean difference between Taxi vs Tetac was -4.23 °C with LoA from -7.22 to -1.23 °C.

CONCLUSIONS

Ingestible capsule measurements are reliable enough to adequately estimate the core body temperature in clinical practice. Its non-invasiveness, and the real-time remote control offer new opportunities for future research into fever during infectious diseases.

Small RNAs in cell-to-cell communications during bacterial infection

Intercellular communication is a widespread phenomenon in all domains of life. Bacteria have developed many ways of communicating with one another and with other species, either prokaryotic or eukaryotic. RNA has been a key molecule since the beginning of life on Earth, and is one of the carriers of information. Given the current antibiotic crisis, understanding the way in which pathogens communicate can lead towards improved ways to control infections when antimicrobial therapy is not possible. Different subspecies of RNA, non-coding, and of small size, designated here as ncRNAs, have been in recent years the subject of a great research effort, and results have contributed to a growing field of knowledge. This review focuses on four different aspects of ncRNA involvement in cell-to-cell communications during bacterial infections: pathogen recognition by the host, alteration of host microRNA profiles, production of domestic and secreted forms of ncRNAs and subversion of the host responses. The current review article focuses on the most recent discoveries in the field and gives an integrative idea based on the discussed studies.

Transcriptomics of Haemophilus (Glässerella) parasuis serovar 5 subjected to culture conditions partially mimetic to natural infection for the search of new vaccine antigens

Background

Haemophilus (Glässerella) parasuis is the etiological agent of Glässer’s disease in pigs. Control of this disorder has been traditionally based on bacterins. The search for alternative vaccines has focused mainly on the study of outer membrane proteins. This study investigates the transcriptome of H. (G.) parasuis serovar 5 subjected to in vitro conditions mimicking to those existing during an infection (high temperature and iron-restriction), with the aim of detecting the overexpression of genes coding proteins exposed on bacterial surface, which could represent good targets as vaccine candidates.

Results

The transcriptomic approach identified 13 upregulated genes coding surface proteins: TbpA, TbpB, HxuA, HxuB, HxuC, FhuA, FimD, TolC, an autotransporter, a protein with immunoglobulin folding domains, another large protein with a tetratricopeptide repeat and two small proteins that did not contain any known domains. Of these, the first six genes coded proteins being related to iron extraction.

Conclusion

Six of the proteins have already been tested as vaccine antigens in murine and/or porcine infection models and showed protection against H. (G.) parasuis. However, the remaining seven have not yet been tested and, consequently, they could become useful as putative antigens in the prevention of Glässer’s disease. Anyway, the expression of this seven novel vaccine candidates should be shown in other serovars different from serovar 5.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1647-1) contains supplementary material, which is available to authorized users.

Recent progress in drug targets and inhibitors towards combating leishmaniasis

Lesihmaniasis is one of the major neglected tropical disease caused by the parasite of the genus Leishmania. The disease has more than one clinical forms and the visceral form is considered fatal. With the lack of potential vaccine, chemotherapy is the major treatment source considered for the control of the disease in the infected people. Drugs including amphotericin B and miltefosine are widely used for the treatment, however, development of resistance by the parasite towards the administered drug and high-toxicity of the drug are of major concern. Hence, more attention has been shown on identifying new targets, effective inhibitors, and better drug delivery system against the disease. This review deals with recent studies on drug targets and exploring their essentiality for the survival of Leishmania. Further, new inhibitors for those targets, novel anti-leishmanial peptides and vaccines against leishmaniasis were discussed. We believe that this pool of information will ease the researchers to gain knowledge and help in choosing right targets and design of new inhibitors against Leishmaniasis.

Explaining changes in child health inequality in the run up to the 2015 Millennium Development Goals (MDGs): The case of Zambia

Background

Child health interventions were drastically scaled up in the period leading up to 2015 as countries aimed at meeting the 2015 target of the Millennium Development Goals (MDGs). MDGs were defined in terms of achieving improvements in average health. Significant improvements in average child health are documented, but evidence also points to rising inequality. It is important to investigate factors that drive the increasing disparities in order to inform the post-2015 development agenda of reducing inequality, as captured in the Sustainable Development Goals (SDGs). We investigated changes in socioeconomic inequality in stunting and fever in Zambia in 2007 and 2014. Unlike the huge literature that seeks to quantify the contribution of different determinants on the observed inequality at any given time, we quantify determinants of changes in inequality.

Methods

Data from the 2007 and 2014 waves of the Zambia Demographic and Health Survey (DHS) were utilized. Our sample consisted of children aged 0–5 years (n = 5,616 in 2007 and n = 12,714 in 2014). We employed multilevel models to assess the determinants of stunting and fever, which are two important child health indicators. The concentration index (CI) was used to measure the magnitude of inequality. Changes in inequality of stunting and fever were investigated using Oaxaca-type decomposition of the CI. In this approach, the change in the CI for stunting/fever is decomposed into changes in CI for each determinant and changes in the effect—measured as an elasticity—of each determinant on stunting/fever.

Results

While average rates of stunting reduced in 2014 socioeconomic inequality in stunting increased significantly. Inequality in fever incidence also increased significantly, but average rates of fever did not reduce.

The increase in the inequality (CI) of determinants accounted for the largest part (42.5%) of the increase in inequality of stunting, while the increase in the effect of determinants explained 35% of the increase. The determinants with the greatest total contribution (change in CI plus change in effect) to the increase in inequality of stunting were mother’s height and weight, wealth, birth order, facility delivery, duration of breastfeeding, and maternal education.

For fever, almost all (86%) the increase in inequality was accounted for by the increase in the effect of determinants of fever, while the distribution of determinants mattered less. The determinants with the greatest total contribution to the increase in inequality of fever were wealth, maternal education, birth order and breastfeeding duration.

In the multilevel model, we found that the likelihood of a child being stunted or experiencing fever depends on the community in which they live.

Conclusions

To curb the increase in inequality of stunting and fever, policy may focus on improving levels of, and reducing inequality in, access to facility deliveries, maternal nutrition (which may be related to maternal weight and height), complementary feeding (for breastfed children), wealth, maternal education, and child care (related to birth order effects). Improving overall levels of these determinants contribute to the persistence of inequality if these determinants are unequally concentrated on the well off to begin with.