Oral Secretions Research Articles

Bioaerosol Sampling in Modern Agriculture: A Novel Approach for Emerging Pathogen Surveillance?

Modern agricultural practices create environmental conditions conducive to the emergence of novel pathogens. Current surveillance efforts to assess the burden of emerging pathogens in animal production facilities in China are sparse. In Guangdong Province pig farms, we compared bioaerosol surveillance for influenza A virus to surveillance in oral pig secretions and environmental swab specimens. During the 2014 summer and fall/winter seasons, we used 3 sampling techniques to study 5 swine farms weekly for influenza A virus. Samples were molecularly tested for influenza A virus, and positive specimens were further characterized with culture. Risk factors for influenza A virus positivity for each sample type were assessed. Seventy-one of 354 samples (20.1%) were positive for influenza A virus RNA by real-time reverse-transcription polymerase chain reaction analysis. Influenza A virus positivity in bioaerosol samples was a statistically significant predictor for influenza A virus positivity in pig oral secretion and environmental swab samples. Temperature of <20°C was a significant predictor of influenza A virus positivity in bioaerosol samples. Climatic factors and routine animal husbandry practices may increase the risk of human exposure to aerosolized influenza A viruses in swine farms. Data suggest that bioaerosol sampling in pig barns may be a noninvasive and efficient means to conduct surveillance for novel influenza viruses.

Oral secretions from Mythimna separata insects specifically induce defence responses in maize as revealed by high-dimensional biological data.

Attack from insect herbivores poses a major threat to plant survival, and accordingly, plants have evolved sophisticated defence systems. Maize is cultivated as a staple crop worldwide, and insect feeding causes large production losses. Despite its importance in agriculture, little is known about how maize reacts to insect herbivory. Taking advantage of advances in sequencing and mass spectrometry technology, we studied the response of maize to mechanical wounding and simulated Mythimna separata (a specialist insect) herbivory by applying its oral secretions (OS) to wounds. In comparison to the responses induced by mechanical wounding, OS elicited larger and longer-lasting changes in the maize transcriptome, proteome, metabolome and phytohormones. Specifically, many genes, proteins and metabolites were uniquely induced or repressed by OS. Nearly 290 transcription factor genes from 39 families were involved in OS-induced responses, and among these, more transcription factor genes were specifically regulated by OS than by wounding. This study provides a large-scale omics dataset for understanding maize response to chewing insects and highlights the essential role of OS in plant-insect interactions.

Turnabout Is Fair Play: Herbivory-Induced Plant Chitinases Excreted in Fall Armyworm Frass Suppress Herbivore Defenses in Maize.

The perception of herbivory by plants is known to be triggered by the deposition of insect-derived factors such as saliva and oral secretions, oviposition materials, and even feces. Such insect-derived materials harbor chemical cues that may elicit herbivore and/or pathogen-induced defenses in plants. Several insect-derived molecules that trigger herbivore-induced defenses in plants are known; however, insect-derived molecules suppressing them are largely unknown. In this study, we identified two plant chitinases from fall armyworm (Spodoptera frugiperda) larval frass that suppress herbivore defenses while simultaneously inducing pathogen defenses in maize (Zea mays). Fall armyworm larvae feed in enclosed whorls of maize plants, where frass accumulates over extended periods of time in close proximity to damaged leaf tissue. Our study shows that maize chitinases, Pr4 and Endochitinase A, are induced during herbivory and subsequently deposited on the host with the feces. These plant chitinases mediate the suppression of herbivore-induced defenses, thereby increasing the performance of the insect on the host. Pr4 and Endochitinase A also trigger the antagonistic pathogen defense pathway in maize and suppress fungal pathogen growth on maize leaves. Frass-induced suppression of herbivore defenses by deposition of the plant-derived chitinases Pr4 and Endochitinase A is a unique way an insect can co-opt the plant's defense proteins for its own benefit. It is also a phenomenon unlike the induction of herbivore defenses by insect oral secretions in most host-herbivore systems.

Infection Control in Prosthodontics

The dentists and allied health workers are exposed to wide variety of potentially dangerous micro-organisms. This occupational potential for disease transmission becomes evident as most human microbial pathogens have been isolated from oral secretions. Because of repeated exposure to the microorganisms present in blood and saliva, the incidence of certain infectious diseases has been significantly higher among dental professionals.HIV, Hepatitis B, Tuberculosis and Herpes simplex virus infections are well recognized and indicate the need for increased understanding of modes of disease transmission and infection control procedures. Dental prostheses, impressions, models and items used in their fabrication are potential sources for cross infectio n and should be handled in a manner that prevents exposure of dental health care professionals and patients to infectious agents. This article highlights various methods of infection control particularly in the field of Prosthodontics to prevent the transmi ssion of diseases between patients, dentists and lab personnel. Routinely dental care professionals are at an increased risk of cross infection while treating patients. This occupational potential for disease transmission becomes evident initially when one realizes that most human microbial pathogens have been isolated from oral secretions. Because of repeated exposure to the microorganisms present in blood and saliva, the incidence of certain infectious diseases has been significantly higher among dental professionals than observed for the general population. Hepatitis B, HIV, Tuberculosis and Herpes Simplex Virus infections are well recognized and indicate the need for increased understanding of modes of disease transmission and infection control procedures by dental care providers. (1)

Chelonid herpesvirus 5 in secretions and tumor tissues from green turtles (Chelonia mydas) from Southeastern Brazil: A ten-year study

Fibropapillomatosis (FP), a neoplastic disease characterized by the formation of multiple tumors affecting different species of sea turtles and, most often, the green turtle (Chelonia mydas), is considered one of the major threats to the survival of this species. Recent studies indicate that Chelonid herpesvirus (ChHV5) is the etiological agent of this disease, though its association with anthropogenically altered environments and the immune status of these animals also appears to contribute to disease expression and tumor formation. In this study, tumor biopsy and secretions from green turtles captured off the coast of São Paulo State, Brazil, were used in histological and molecular analyses to detect and characterize circulating ChHV5. In 40.9% of cases, the tumor histopathological findings revealed focal ballooning degeneration with intranuclear inclusion bodies, results which are suggestive of viral infection. ChHV5 was detected using polymerase chain reaction (PCR) on the animals’ skin, ocular tumor biopsies, and ocular and oral secretions. The analysis of the detected ChHV5 sequences revealed two distinct genetic sequences together. Phylogenetic analysis indicated that Brazilian samples were similar to ChHV5 samples described for the Atlantic phylogeographic group and are therefore part of the same clade as the Gulf of Guinea and Puerto Rico samples. This similarity suggests a possible flow of the virus between these three regions.

Endotracheal Tubes with Subglottic Suctioning Reduce Ventilator-Associated Pneumonia in Trauma Patients

Ventilator-associated pneumonia (VAP), caused by aspiration of oral secretions that collect above the endotracheal tube (ETT) cuff, increases the risk

New Strategies to Prevent Ventilator-Associated Pneumonia: What to Do for Your Patients

The current rates of ventilator-associated pneumonia (VAP) are falling, in large part, as a result of effective prevention strategies. However, the application and efficacy of VAP prevention is being challenged by efforts to replace VAP surveillance with monitoring for ventilator-associated complications (VAC), which include many non-infectious processes. VAP prevention is based on interrupting pneumonia pathogenesis by avoiding the inoculation of contaminated oral secretions into the lower respiratory tract. This starts by using non-invasive ventilation in place of endotracheal intubation whenever possible, placing all tracheal and gastric tubes through the mouth and not the nose, and making daily efforts to liberate patients from mechanical ventilation. Intervention strategies to avoid microaspiration of oral contents to the lung have focused on the use of modified respiratory therapy equipment. This includes endotracheal tubes with subglottic secretion drainage channels, endotracheal tube cuffs made of special materials and of special shape, adaptation of endotracheal tube materials to prevent the development of biofilm, cleaning tubes with biofilm removal devices, and using devices to maintain endotracheal tube cuff pressure. Decontamination of oral secretions with chlorhexidine is commonly incorporated, as part of routine oral care, in many patients. The use of 24 h of prophylactic antibiotics after emergent intubation is also a valuable strategy, but controversy about selective digestive and selective oral decontamination persists, because of concerns about the emergence of antibiotic resistance, particularly in ICUs with high baseline rates of resistance. Other interventions are of less certain benefit, such as post-pyloric feeding, elevation of the head of the bed, and use of probiotics. This review makes recommendations about which current prevention strategies have the greatest potential to reduce the frequency of VAP.

A conserved pattern in plant-mediated interactions between herbivores.

Plant-mediated interactions between herbivores are important determinants of community structure and plant performance in natural and agricultural systems. Current research suggests that the outcome of the interactions is determined by herbivore and plant identity, which may result in stochastic patterns that impede adaptive evolution and agricultural exploitation. However, few studies have systemically investigated specificity versus general patterns in a given plant system by varying the identity of all involved players. We investigated the influence of herbivore identity and plant genotype on the interaction between leaf-chewing and root-feeding herbivores in maize using a partial factorial design. We assessed the influence of leaf induction by oral secretions of six different chewing herbivores on the response of nine different maize genotypes and three different root feeders. Contrary to our expectations, we found a highly conserved pattern across all three dimensions of specificity: The majority of leaf herbivores elicited a negative behavioral response from the different root feeders in the large majority of tested plant genotypes. No facilitation was observed in any of the treatment combinations. However, the oral secretions of one leaf feeder and the responses of two maize genotypes did not elicit a response from a root-feeding herbivore. Together, these results suggest that plant-mediated interactions in the investigated system follow a general pattern, but that a degree of specificity is nevertheless present. Our study shows that within a given plant species, plant-mediated interactions between herbivores of the same feeding guild can be stable. This stability opens up the possibility of adaptations by associated organisms and suggests that plant-mediated interactions may contribute more strongly to evolutionary dynamics in terrestrial (agro)ecosystems than previously assumed.

Ketofol versus fentofol as induction agents for endotracheal intubation in emergency room

Methods The study was a randomized, double blinded study conducted between April 2014 and September 2014 in our Tertiary care Research Institute and Hospital. All Patients presenting to Emergency Department in need of Endotracheal Intubation were included in the study. The drugs used as Induction agents for Endotracheal Intubation were randomly numbered in Pre-filled syringes every day. Propofol was given in a dose 1.5 mg/kg (100 mg) for all patients in study population. Ketamine at 1 mg /kg (Group A) and Fentanyl at 1 μg/kg (Group B) were numbered and kept in 10 ml Prefilled syringes, either one of which was administered along with Propofol. The primary outcomes were based on the Sedation level using the Ramsay Sedation Scale (RSS) and adverse respiratory events based on Quebec Criteria. Secondary outcomes were based on Hypotension, Cormack Lehane Grading, gag reflex, successful attempts at Intubation, oral and tracheobroncheal secretions, sedation time, procedure time, recovery time, recovery agitation and Optic nerve sheath diameter. Patients with Cardio-respiratory arrest, age less than 18 years, head injury, glaucoma, hypotension, evidence of raised ICP and failure to give consent were excluded from the study. Results A total of 286 patients were eligible for the study, of which 104 were included. 54 patients were randomized to Group A (Propofol plus Ketamine) and 50 patients were randomized to Group B (Propofol plus Fentanyl). RSS of ≥ 5 was considered adequate. 45 (83.33%) patients in Group A and 39 (78%) patients in Group B had adequate sedation. Overall Incidence of Adverse respiratory events was less in Group A with 9 (9.25%) patients compared with Group B with 16 (32%) patients. Secondary outcome criteria had minimal statistically significant difference, especially reduced incidence of hypotension in Group A compared to Group B.

Further Assessment of Monkeypox Virus Infection in Gambian Pouched Rats (Cricetomys gambianus) Using In Vivo Bioluminescent Imaging.

Monkeypox is a zoonosis clinically similar to smallpox in humans. Recent evidence has shown a potential risk of increased incidence in central Africa. Despite attempts to isolate the virus from wild rodents and other small mammals, no reservoir host has been identified. In 2003, Monkeypox virus (MPXV) was accidentally introduced into the U.S. via the pet trade and was associated with the Gambian pouched rat (Cricetomys gambianus). Therefore, we investigated the potential reservoir competence of the Gambian pouched rat for MPXV by utilizing a combination of in vivo and in vitro methods. We inoculated three animals by the intradermal route and three animals by the intranasal route, with one mock-infected control for each route. Bioluminescent imaging (BLI) was used to track replicating virus in infected animals and virological assays (e.g. real time PCR, cell culture) were used to determine viral load in blood, urine, ocular, nasal, oral, and rectal swabs. Intradermal inoculation resulted in clinical signs of monkeypox infection in two of three animals. One severely ill animal was euthanized and the other affected animal recovered. In contrast, intranasal inoculation resulted in subclinical infection in all three animals. All animals, regardless of apparent or inapparent infection, shed virus in oral and nasal secretions. Additionally, BLI identified viral replication in the skin without grossly visible lesions. These results suggest that Gambian pouched rats may play an important role in transmission of the virus to humans, as they are hunted for consumption and it is possible for MPXV-infected pouched rats to shed infectious virus without displaying overt clinical signs.

The clinical features of respiratory infections caused by the Streptococcus anginosus group.

BackgroundThe Streptococcus anginosus group (SAG) play important roles in respiratory infections. It is ordinarily difficult to distinguish them from contaminations as the causative pathogens of respiratory infections because they are often cultured in respiratory specimens. Therefore, it is important to understand the clinical characteristics and laboratory findings of respiratory infections caused by the SAG members. The aim of this study is to clarify the role of the SAG bacteria in respiratory infections.MethodsA total of 30 patients who were diagnosed with respiratory infections which were caused by the SAG bacteria between January 2005 and February 2015 were retrospectively evaluated.ResultsRespiratory infections caused by the SAG were mostly seen in male patients with comorbid diseases and were typically complicated with pleural effusion. Pleural effusion was observed in 22 (73.3%) patients. Empyema was observed in half of the 22 patients with pleural effusion. S. intermedius, S. constellatus and S. anginosus were detected in 16 (53.3 %), 11 (36.7 %) and 3 (10.0 %) patients, respectively. Six patients had mixed-infections. The duration from the onset of symptoms to the hospital visit was significantly longer in “lung abscess” patients than in “pneumonia” patients among the 24 patients with single infections, but not among the six patients with mixed-infection. The peripheral white blood cell counts of the “pneumonia” patients were higher than those of the “lung abscess” patients and S. intermedius was identified significantly more frequently in patients with pulmonary and pleural infections (pneumonia and lung abscess) than in patients with bacterial pleurisy only. In addition, the patients in whom S. intermedius was cultured were significantly older than those in whom S. constellatus was cultured.ConclusionsRespiratory infections caused by the SAG bacteria tended to be observed more frequently in male patients with comorbid diseases and to more frequently involve purulent formation. In addition, S. intermedius was mainly identified in elderly patients with having pulmonary infection complicated with pleural effusion, and the aspiration of oral secretions may be a risk factor in the formation of empyema thoracis associated with pneumonia due to S. intermedius.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-015-0128-6) contains supplementary material, which is available to authorized users.

Routes of Hendra Virus Excretion in Naturally-Infected Flying-Foxes: Implications for Viral Transmission and Spillover Risk.

Pteropid bats or flying-foxes (Chiroptera: Pteropodidae) are the natural host of Hendra virus (HeV) which sporadically causes fatal disease in horses and humans in eastern Australia. While there is strong evidence that urine is an important infectious medium that likely drives bat to bat transmission and bat to horse transmission, there is uncertainty about the relative importance of alternative routes of excretion such as nasal and oral secretions, and faeces. Identifying the potential routes of HeV excretion in flying-foxes is important to effectively mitigate equine exposure risk at the bat-horse interface, and in determining transmission rates in host-pathogen models. The aim of this study was to identify the major routes of HeV excretion in naturally infected flying-foxes, and secondarily, to identify between-species variation in excretion prevalence. A total of 2840 flying-foxes from three of the four Australian mainland species (Pteropus alecto, P. poliocephalus and P. scapulatus) were captured and sampled at multiple roost locations in the eastern states of Queensland and New South Wales between 2012 and 2014. A range of biological samples (urine and serum, and urogenital, nasal, oral and rectal swabs) were collected from anaesthetized bats, and tested for HeV RNA using a qRT-PCR assay targeting the M gene. Forty-two P. alecto (n = 1410) had HeV RNA detected in at least one sample, and yielded a total of 78 positive samples, at an overall detection rate of 1.76% across all samples tested in this species (78/4436). The rate of detection, and the amount of viral RNA, was highest in urine samples (>serum, packed haemocytes >faecal >nasal >oral), identifying urine as the most plausible source of infection for flying-foxes and for horses. Detection in a urine sample was more efficient than detection in urogenital swabs, identifying the former as the preferred diagnostic sample. The detection of HeV RNA in serum is consistent with haematogenous spread, and with hypothesised latency and recrudesence in flying-foxes. There were no detections in P. poliocephalus (n = 1168 animals; n = 2958 samples) or P. scapulatus (n = 262 animals; n = 985 samples), suggesting (consistent with other recent studies) that these species are epidemiologically less important than P. alecto in HeV infection dynamics. The study is unprecedented in terms of the individual animal approach, the large sample size, and the use of a molecular assay to directly determine infection status. These features provide a high level of confidence in the veracity of our findings, and a sound basis from which to more precisely target equine risk mitigation strategies.

Spruce Budworm (Lepidoptera: Tortricidae) Oral Secretions I: Biology and Function

The potential roles of the oral secretions (OS) of spruce budworm (SBW; Choristoneura fumiferana Clemens) larvae and factors that may affect the volume of OS disgorged were investigated in the laboratory. Experiments revealed that diet-fed SBW larvae readily disgorge OS when induced ("milked"), with minimal overall cost to their development and eventual pupal weight. Exposure of conspecific larvae to OS throughout larval development negatively affected survival and male pupal weight; however, male development time was faster when exposed to OS. Female pupal weight and development time were not affected. Preliminary experiments suggested that OS had a repellent effect on a co-occurring herbivore, the false hemlock looper, Nepytia canosaria (Walker). OS produced by larvae that fed on three host tree species and on artificial diet significantly increased the grooming time of ants (Camponotus sp.), indicating that SBW OS have an anti-predator function. The volume of OS is significantly greater in L6 than in L4 or L5, with the volume produced by L6 depending on weight and age as well as feeding history at time of milking. These findings indicate that SBW OS function as both an intra- and interspecific epideictic pheromone and as an anti-predator defensive mechanism, while incurring minimal metabolic costs.

Spruce Budworm (Lepidoptera: Tortricidae) Oral Secretions II: Chemistry.

As sessile organisms, plants have evolved different methods to defend against attacks and have adapted their defense measures to discriminate between mechanical damage and herbivory by insects. One of the ways that plant defenses are triggered is via elicitors from insect oral secretions (OS). In this study, we investigated the ability of second-instar (L2) spruce budworm [SBW; Choristoneura fumiferana (Clemens)] to alter the volatile organic compounds (VOCs) of four conifer species [Abies balsamea (L.) Mill., Picea mariana (Miller) B.S.P., Picea glauca (Moench) Voss, Picea rubens (Sargent)] and found that the emission profiles from all host trees were drastically changed after herbivory. We then investigated whether some of the main elicitors (fatty acid conjugates [FACs], β-glucosidase, and glucose oxidase) studied were present in SBW OS. FACs (glutamine and glutamic acid) based on linolenic, linoleic, oleic, and stearic acids were all observed in varying relative quantities. Hydroxylated FACs, such as volicitin, were not observed. Enzyme activity for β-glucosidase was also measured and found present in SBW OS, whereas glucose oxidase activity was not found in the SBW labial glands. These results demonstrate that SBW L2 larvae have the ability to induce VOC emissions upon herbivory and that SBW OS contain potential elicitors to induce these defensive responses. These data will be useful to further evaluate whether these elicitors can separately induce the production of specific VOCs and to investigate whether and how these emissions benefit the plant.

The Case Files

The Case Files

Food for Thought: A Review of Food Bolus Impactions at a Tertiary Referral Center

Introduction: Esophageal food bolus impactions (EFBI) are common gastrointestinal emergencies. While nearly 80% will pass spontaneously, endoscopic intervention is often required for persistent impactions. The incidence of EFBI is increasing and is often associated with underlying esophageal pathology, which is often undiagnosed. Methods: Patients presenting with symptoms of an EFBI (dysphagia, chest pain, foreign body sensation, inability to tolerate oral secretions) confirmed on and subsequently treated by upper endoscopy from 2008 to 2014 were included. Patients with non-food impactions were excluded. A retrospective review of medical records was performed to collect clinical, endoscopic, radiological and pathological data. Results: A total of 137 patients were identified with a median age of 51 (from 20 to 98 years), comprising 87 men (64%) and 50 women (36%). The average time to endoscopy from presentation was 5.8 hours. The types of anesthesia used included general anesthesia(34%), monitored anesthesia care (57%) and conscious sedation (9%). Impactions were found in the upper (30%), mid (24%) and lower (43%) esophagus. Structural abnormalities were found in 80 of 137 patients (58%) (Table 1). The incidence of eosinophilic esophagitis (EE) was 18%. Of the 50 cases that revealed no mucosal abnormalities, only one had a biopsy during the index procedure (which revealed EE). Only two others had subsequent biopsies, one of which revealed EE. Features suggestive of EE were noted in 31 cases of which only 15 had a biopsy; 13 were positive for EE. Eighty-two patients had pre-procedural imaging, of which 21 (24%) revealed a foreign body. The food bolus was advanced in to the stomach in 23% of the cases while an array of grasping instruments were used to extract the bolus in the rest. The complication rate was 2.9% with 3 cases of superficial mucosal tears and one case of aspiration.Table 1Conclusion: Our data demonstrates that endoscopic intervention for EFBI is generally safe and successful. Only a small proportion of patients with no obvious mucosal disease or with features suggestive of EE had biopsies performed to exclude EE at the time of the index endoscopy. In addition these data suggest that routine pre-procedural imaging for the diagnosis of food impactions is inaccurate and does not impact clinical decision-making. Outpatient follow-up after endoscopy was poor. These are aspects of management that should be considered for quality improvement.

Maize Plants Recognize Herbivore-Associated Cues from Caterpillar Frass

Caterpillar behaviors such as feeding, crawling, and oviposition are known to induce defenses in maize and other plant species. We examined plant defense responses to another important caterpillar behavior, their defecation. Fall armyworms (FAW, Spodoptera frugiperda), a major threat to maize (Zea mays), are voracious eaters and deposit copious amounts of frass in the enclosed whorl tissue surrounding their feeding site, where it remains for long periods of time. FAW frass is composed of molecules derived from the host plant, the insect itself, and associated microbes, and hence provides abundant cues that may alter plant defense responses. We observed that proteins from FAW frass initially induced wound-responsive defense genes in maize; however, a pathogenesis-related (pr) defense gene was induced as the time after application increased. Elicitation of pathogen defenses by frass proteins was correlated with increased herbivore performance and reduced fungal pathogen performance over time. These responses differ from the typical plant response to oral secretions of the FAW. The results pave the way for identification of protein molecule(s) from the excretion of an herbivore that elicits pathogen defense responses while attenuating herbivore defenses in plants.

Babinski-Nageotte Syndrome Secondary to Hemorrhagic Medullary Cavernoma in a District Hospital: A Variant of Wallernberg Syndrome

Babinski-Nageotte syndrome is a rare clinical entity in a young healthy individual. This syndrome includes a group of neurological symptoms resulting from injury to both medial and lateral medulla of the brain. It is a variant of Wallernberg syndrome. This case report describes a 27 year old healthy Malay gentleman who presented with a three day history of right facial numbness and weakness associated with left sided body hemiparesis and hemiparethesia. He had obvious right hypoglossal nerve palsy. He also complained of vertigo, dysphagia, dysarthria and vomiting. He denied having any hiccups. Physical examination revealed an obvious right Horner’s syndrome with upper motor neuron right facial nerve palsy. There was no facial tenderness. Motor power of the left upper and lower limbs were graded as 2/5. His gag reflex on the right side was absent with abundant oral secretions. Jerky nystagmus of the right eye at all gazes was seen along with diplopia. A plain computed tomography scan of the brain showed a hyperdense lesion suggestive of hemorrhagic medullary cavernoma. He subsequently developed respiratory distress due to pneumonia in which he required mechanical ventilation. However, he succumbed to his illness due to Extended Spectrum Beta Lactamase (ESBL) Klebsiella pneumonia on day 6 of admission. This crossed finding is diagnostic of Babinski-Nageotte syndrome. The unavailability of Magnetic Resonance Imaging/Angiography facility may provide a diagnostic challenge to elucidate the exact etiology for this syndromein a district hospital.

Expression of chicken interleukin-2 by a highly virulent strain of Newcastle disease virus leads to decreased systemic viral load but does not significantly affect mortality in chickens.

BackgroundIn mammals, interleukin 2 (IL-2) has been shown to decrease replication or attenuate pathogenicity of numerous viral pathogens (herpes simplex virus, vaccinia virus, human respiratory syncytial virus, human immunodeficiency virus) by activating natural killer cells (NK), cytotoxic T lymphocytes and expanding subsets of memory cells. In chickens, IL-2 has been shown to activate T cells, and as such it might have the potential to affect replication and pathogenesis of Newcastle disease virus (NDV).MethodsTo assess the effect of IL-2 during NDV infection in chickens, we produced a recombinant virulent NDV strain expressing chicken IL-2 (rZJ1-IL2). The effects of IL-2 expression were investigated in vivo using the intracerebral pathogenicity index (ICPI) in day-old chicks and pathogenesis experiments in 4-week-old chickens. In these studies, rZJ1-IL2 was compared to a control virus expressing the green fluorescent protein (rZJ1-GFP). Assessed parameters included survival curves, detailed histological and immunohistochemical grading of lesions in multiple organs, and virus isolation in blood, spleen and mucosal secretions of infected birds.ResultsAt the site of infection (eyelid), expression of IL-2 was demonstrated in areas of rZJ-IL2 replication, confirming IL-2 production in vivo. Compared to rZJ1-GFP strain, rZJ1-IL2 caused milder lesions and displayed decreased viral load in blood, spleen and mucosal secretions of infected birds. In the rZJ1-IL2-infected group, virus level in the blood peaked at day 4 post-infection (pi) (103.46 EID50 /0.1 ml) and drastically decreased at day 5 pi (100.9 EID50/0.1 ml), while in the rZJ1-GFP-infected group virus levels in the blood reached 105.35 EID50/0.1 ml at day 5. However, rZJ1-IL2-infected groups presented survival curves similar to control birds infected with rZJ1-GFP, with comparable clinical signs and 100 % mortality. Further, expression of IL-2 did not significantly affect the ICPI scores, compared to rZJ1-GFP strain.ConclusionsIncreased expression of chicken IL-2 during virulent NDV replication in naïve chickens decreased viral titers in blood, spleens, oral and cloacal secretions on day 4–5 post infection. This is consistent with the previously described role of IL-2 in enhancing the clearance of viruses in mammals, such as human respiratory syncytial virus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-015-0353-x) contains supplementary material, which is available to authorized users.

Efficiency of a mechanical device in controlling tracheal cuff pressure in intubated critically ill patients: a randomized controlled study.

BackgroundCuff pressure (Pcuff) control is mandatory to avoid leakage of oral secretions passing the tracheal tube and tracheal ischemia. The aim of the present trial was to determine the efficacy of a mechanical device (PressureEasy®) in the continuous control of Pcuff in patients intubated with polyvinyl chloride (PVC)-cuffed tracheal tubes, compared with routine care using a manometer.MethodsThis is a prospective, randomized, controlled, cross-over study. All patients requiring intubation with a predicted duration of mechanical ventilation ≥48 h were eligible. Eighteen patients randomly received continuous control of Pcuff with PressureEasy® device for 24 h, followed by discontinuous control (every 4 h) with a manual manometer for 24 h, or vice versa. Pcuff and airway pressure were continuously recorded. Pcuff target was 25 cmH2O during the two periods.ResultsThe percentage of time spent with Pcuff 20–30 cmH2O (median (IQR) 34 % (17–57) versus 50 % (35–64), p = 0.184) and the percentage of time spent with Pcuff <20 cmH2O (23 % (5–63) versus 43 % (16–60), p = 0.5) were similar during continuous control of Pcuff and routine care, respectively. However, the percentage of time spent with Pcuff >30 cmH2O was significantly higher during continuous control compared with routine care of tracheal cuff (26 % (14–39) versus 7 % (1–18), p = 0.002). No significant difference was found in Pcuff (25 (18–28) versus 21 (18–26), p = 0.17), mean airway pressure (14 (10–17) versus 14 (11–16), p = 0.679), or coefficient of variation of Pcuff (19 % (11–26) versus 20 % (11–25), p = 0.679) during continuous control compared with routine care of tracheal cuff, respectively.ConclusionsPressureEasy® did not demonstrate a better control of Pcuff between 20 and 30 cmH2O, compared with routine care using a manometer. Moreover, the device use resulted in significantly higher time spent with overinflation of tracheal cuff, which might increase the risk for tracheal ischemic lesions.Trial registrationClinicaltrial.gov: NCT02109003