Mucus Trap Research Articles

Mucus-Trap-Assisted Feeding Is a Common Strategy of the Small Mixoplanktonic Prorocentrum pervagatum and P. cordatum (Prorocentrales, Dinophyceae).

Prorocentrum comprises a diverse group of bloom-forming dinophytes with a worldwide distribution. Although photosynthetic, mixoplanktonic phagotrophy has also been described. Recently, the small P. cf. balticum was shown to use a remarkable feeding strategy by crafting globular mucus traps to capture and immobilize potential prey. Here we present evidence showing that two additional related species, the recently described P. pervagatum and the cosmopolitan bloom-forming P. cordatum, also produce large (80-120 µm) mucus traps supporting their mixoplanktonic activity. Prey are captured within the traps either through passive entanglement upon contact with the outside surface, or through active water movement created by rotating Prorocentrum cells eddying particles to the inside surface where trapped live prey cells became immobilized. Entrapment in mucus assisted deployment into the prey of a peduncle extruded from the apical area of the Prorocentrum cell. Phagotrophy by P. pervagatum supported faster growth compared to unfed controls and time series quantification of food vacuoles revealed ingestion rates of ca. 10-12 Teleaulax prey cells day-1. Model calculations show clear advantages of deploying a mucus trap for increasing prey encounter rates. This study demonstrates that the large size and immobilization properties of mucus traps successfully increase the availability of prey for small Prorocentrum species, whose peduncle feeding mode impedes consumption of actively moving prey, and that this strategy is common among certain clades of small planktonic Prorocentrum species.

The loss of mixotrophy in Alexandrium pseudogonyaulax: Implications for trade‐offs between toxicity, mucus trap production, and phagotrophy

AbstractTwo important competitive traits in protists, particularly in harmful algal bloom forming species, are lytic toxicity and mixotrophy. This study focuses on Alexandrium pseudogonyaulax, a dinoflagellate species that is both toxic and mixotrophic, and in addition uses a mucus trap to immobilize and capture potential prey. A single strain of A. pseudogonyaulax was subcultured and grown under two different conditions; one subculture was grown autotrophically, while the other was periodically offered algal prey. After 3 yr, the substrain that was fed remained an avid mixotroph, while the autotrophically grown substrain almost completely lost its ability to feed. The emergence of these two “substrains,” with different nutritional strategies, allowed us to investigate possible trade‐offs between lytic toxicity, mixotrophy, and mucus trap production. Both substrains were still capable of producing mucus traps, and successfully captured other cells. Although the nonfeeding substrain lost its ability to feed, it was more lytic than the feeding substrain, which may suggest a trade‐off between lytic toxicity and feeding ability. However, this increased toxicity was not enough to outcompete other faster growing competitors such as Teleaulax acuta and Heterocapsa rotundata. In contrast, the feeding substrain was able to inhibit the growth of these same competing species. The results indicate that for A. pseudogonyaulax, the benefits of phagotrophy far outweigh those of lytic toxicity or the mucus trap alone. The nonfeeding strain used here provides evidence of the loss of mixotrophy under culture conditions, highlighting one of the obstacles in the study of mixotrophic protists.

The use of multiplex PCR for the detection of atypical pathogens in Egyptian children with CAP: a high rate of Bordetella pertussis in early infancy

BackgroundAtypical pathogen infections played an important role in community-acquired pneumonia (CAP) in children. Pathogen-specific clinical symptoms are often lacking, and it is difficult to detect atypical pathogens by culture methods. The use of multiplex polymerase chain reaction (PCR) methods enables testing for many pathogens simultaneously in a single analysis.AimTo determine the role of atypical pathogens in children hospitalized with CAP.Patients and methodsThis cross-sectional study was conducted throughout a 2-year period from August 2015 to September 2017. It included 400 Egyptian children hospitalized with clinical diagnosis of CAP at a tertiary hospital in Cairo, Egypt. Sputum samples were collected from lower respiratory tract of all enrolled patients by mucus trap catheter for identification of Bordetella pertussis, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophilia by using multiplex real-time PCR.ResultsAmong the 400 CAP patients enrolled in this study, atypical pathogens were detected in 12/400 (3%) patients. Bordetella pertussis was detected in 2% of cases, and it was responsible for CAP in 8/104 (7.69%) infants in the age stratum ≤ 4 months; compared with pertussis-negative cases, pertussis-positive cases were younger and incompletely vaccinated (P values were 0.001 and 0.007, respectively). Mycoplasma pneumoniae was detected in 1% of cases, all were among the age stratum > 4 months ≤ 59 months in 4/272 (1.47%) children.ConclusionIn early infancy, Bordetella pertussis causes a significant proportion of hospitalized CAP cases; all were ≤ 4 months old and incompletely vaccinated. This finding could suggest the role of maternal immunization in developing countries.

A search for mixotrophy and mucus trap production in Alexandrium spp. and the dynamics of mucus trap formation in Alexandrium pseudogonyaulax

Recently, a hitherto unknown feeding strategy, the toxic mucus trap, was discovered in the dinoflagellate Alexandrium pseudogonyaulax. In this study, over 40 strains of 8 different Alexandrium species (A. ostenfeldii, A. tamarense, A. catenella, A. taylorii, A. margalefii, A. hiranoi, A. insuetum and A. pseudogonyaulax) were screened for their ability to ingest prey and/or to form mucus traps. The mucus trap feeding strategy, where a mucus trap is towed by the longitudinal flagellum remains unique to A. pseudogonyaulax. In additional experiments, details of the trap were examined and quantified, such as speed and frequency of trap formation as well as what happens to the trap after the A. pseudogonyaulax cell detaches from it. The percentage of A. pseudogonyaulax cells producing a mucus trap and the number of prey cells caught increased with increasing prey concentration, whereas the physical size of the traps was independent of prey concentration. In one strain given an excess of prey, within 1h over 90% of individual A. pseudogonyaulax cells had formed a trap, each containing an average of 45 prey cells. Individual A. pseudogonyaulax cells steadily produced traps and up to 5 traps were produced by a single A. pseudogonyaulax cell after only 24h. The attachment of an A. pseudogonyaulax cell to the trap only ceased during, and just following, cell division. Prey cells were, to some extent, capable of escaping from the mucus trap, but the trap remained sticky and continued catching prey for up to 48h after the trap had been abandoned by the A. pseudogonyaulax cell. These results reveal that the effects of the mucus trap extend far beyond the removal of prey through ingestion, and the potential impact of this strategy on surrounding cells is high.

Harmful effects of Dinophysis to the ciliate Mesodinium rubrum: Implications for prey capture

Toxigenic Dinophysis spp. are obligate mixotrophic dinoflagellates that require a constant supply of prey—Mesodinium rubrum—to achieve long-term growth by means of kleptoplasty. Mesodinium rubrum is, however, a fast moving, jumping ciliate exhibiting an effective escape response from suspensivorous predators. In the present study, a series of laboratory experiments evaluating the motility and survival of M. rubrum in the presence of Dinophysis cells and/or substances contained in their culture medium was designed, in order to assess the mechanisms involved in prey capture by Dinophysis spp. Cell abundance of M. rubrum decreased in the presence of Dinophysis cf. ovum cells producing okadaic acid (OA; up to 7.94±2.67pgcell−1) and smaller amounts of dinophysistoxin-1 (DTX-1) and pectenotoxin-2 (PTX-2). Prey capture was often observed after the ciliate had been attached to adhesive “mucus traps”, which only appeared in the presence of Dinophysis cells. Before being attached to the mucus traps, M. rubrum cells reduced significantly their swimming frequency (from ∼41 to 19±3 jumps min−1) after only 4h of initial contact with D. cf. ovum cells. M. rubrum survival was not affected in contact with purified OA, DTX-1 and PTX-2 solutions, but decreased significantly when the ciliate was exposed to cell-free or filtered culture medium from both D. cf. ovum and D. caudata, the latter containing moderate concentrations of free eicosapentaenoic acid and docosahexaenoic acid. The results thus indicate that Dinophysis combines the release of toxic compounds other than shellfish toxins, possibly free PUFAs, and a “mucus trap” to enhance its prey capture success by immobilizing and subsequently arresting M. rubrum cells.

The use of a mucus trap by Dinophysis acuta for the capture of Mesodinium rubrum prey under culture conditions

A capture mechanism observed in a culture of the dinoflagellate Dinophysis acuta when preying on the ciliate Mesodinium rubrum (also sometimes referred to as Myrionecta rubra) is described. The dinoflagellate released cohesive clumps of mucilage into the culture media. When M. rubrum cells came into contact with this mucilage, they were immediately immobilized, but remained alive for a short period of time. Observations of D. acuta cells ‘visiting and probing’ trapped M. rubrum cells were made and at a critical point D. acuta cells removed individual M. rubrum cells from the mucus to swim away with them. The removal of M. rubrum from the mucus coincided with the cells losing all their cilia and becoming swollen, presumably signifying the death of the cell. These changes may enable the D. acuta peduncle to penetrate the ciliate cell cortex. It is hypothesized that toxins produced by D. acuta play a role in the immobilization process within the mucilage trap.

Reduced susceptibility of carbapenem-resistant Klebsiella pneumoniae to biocides: An emerging threat

Dealing with carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains, which are generally pan-drug resistant, is an uphill task for health care professionals. Owing to limited therapeutic options and the possibility of development of resistance to commonly used biocides in hospital settings, CR-Kp infections pose a serious threat of emergence of a dreaded pandemic. The aim of the study was to highlight the possibility of emergence of biocide resistance among CR-Kp strains. A case study was conducted in a Super-specialty Hospital in September 2015. A 65-year-old female patient post-laparotomy was admitted to the General Intensive Care Unit of a Super-specialty Hospital. CR-Kp was isolated from the blood and mucus trap samples of this patient. Susceptibility testing of three commonly used biocides in our hospital, namely sodium hypochlorite (4% available chlorine), 5% w/v povidone iodine (0.5% w/v of available iodine) and absolute ethanol (99.9%), respectively, was carried out using K. pneumoniae ATCC 700603 as control. The test isolate showed reduced susceptibility to sodium hypochlorite in comparison to K. pneumoniae ATCC 700603. The possibility of emergence of biocide resistance among CR-Kp strains poses a threat of disrupting our ongoing efforts for implementation of effective infection control measures.

Toxic mucus traps: A novel mechanism that mediates prey uptake in the mixotrophic dinoflagellate Alexandrium pseudogonyaulax

The functional role of harmful substances (i.e. toxins) produced by marine planktonic algae is still, in many cases, unknown. This study describes a novel mechanism by which the phototrophic dinoflagellate Alexandrium pseudogonyaulax secretes a toxic mucus trap where prey items are caught and immobilized prior to ingestion. Prey cells remain entrapped and immobile in the mucus trap, but most stay intact, readily available as whole-cell prey. It is shown that food uptake by A. pseudogonyaulax increases its growth rate considerably even in nutrient-replete, high-light conditions. The increase in growth rate was more enhanced in light-limited treatments and A. pseudogonyaulax grew significantly faster when fed Heterocapsa rotundata, than when fed Teleaulax acuta under both light conditions. For comparison, strains of Alexandrium catenella and Alexandrium minutum were studied for their mixotrophic capabilities. None of these strains were mixotrophic under the conditions provided. In addition, the toxic effects on various protistan targets of these Alexandrium strains as well as Alexandrium tamarense and Alexandrium ostenfeldii were compared to that of A. pseudogonyaulax. A. tamarense and A. catenella did immobilize and lyse target cells through substances leaked directly into the water, differing from all the strains of A. pseudogonyaulax studied. Results show that the toxic effect of A. pseudogonyaulax is non-specific causing nearly 100% immobilization of a variety of protistan targets at relatively low cell concentrations (500cellsml−1 of donor cell). A critical donor cell density was not required as only one A. pseudogonyaulax cell was able to cause immobilization of target cells. For the first time, the connection between excreted toxins and phagotrophy is evident in an Alexandrium species and this particular strategy has the potential to severely impact competing phytoplankton communities.

Mucus trap in coral reefs: formation and temporal evolution of particle aggregates caused by coral mucus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 307:69-84 (2006) - doi:10.3354/meps307069 Mucus trap in coral reefs: formation and temporal evolution of particle aggregates caused by coral mucus Markus Huettel1,3,*, Christian Wild1,4, Sabine Gonelli2 1Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359 Bremen, Germany2Davao del Norte State College, New Visayas, Panabo City, Davao del Norte, Philippines3Present address: Florida State University, Department of Oceanography, West Call Street, OSB517, Tallahassee,Florida 32306-4320, USA4Present address: UNESCO, Intergovernmental Oceanographic Commission, 1 rue Miollis, 75015 Paris, France *Email: mhuettel@ocean.fsu.edu ABSTRACT: Corals exude large volumes of nutrient-containing mucus when exposed to air during low spring tides, as a protective mechanism against desiccation and UV radiation. Currents and waves of the incoming flood detach the mucus from the corals, thereby increasing organic carbon and nutrient concentrations in the reef water. During transport into the reef lagoon, a large fraction of the mucus dissolves. Roller-table experiments demonstrated that this dissolved mucus leads to the formation of marine snow. The non-dissolving gel-like fraction of the mucus rapidly accumulates suspended particles from the flood water and forms in temporal sequence mucus strings, flocs, surface films, surface layers and thick mucus floats. In a platform reef in the Great Barrier Reef, Australia, we characterized each of these mucus phases and observed the exponential increase of algal and bacterial cells in the ageing mucus aggregates. Within 3 hours, the dry weight of the aggregates increased 35-fold, chlorophyll a 192-fold, bacteria cell density 546-fold, C 26-fold, and N 79-fold. After waves destroy the buoyant mucus floats, the mucus aggregates release enclosed gas bubbles and quickly sink to the lagoon sediments, where they are consumed by the benthic community. This releases aggregate-bound nutrients, which fuel benthic and planktonic production in the lagoon. During ebb tide, corals filter the lagoon water and close the recycling loop. We conclude that coral mucus enhances the filtration capacity of coral reefs and fuels reef benthos, thereby increasing the import of oceanic particles and enhancing recycling in the reef ecosystem. KEY WORDS: Mucus · Coral reefs · Nutrient recycling · Permeable sediment · Marine snow · TEP Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 307. Online publication date: January 24, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.

An improvised oral mucus extractor for neonates — A simple low costing method

Every birth is an emergency as the first few moments of an infant's life can be critical to prevent birth asphyxia, which is one of the leading causes of neonatal mortality and morbidity in India [1]. Apart from well trained personnel, proper equipment must be available in the delivery room for timely resuscitation that can have a lifetime consequence. Simple steps in resuscitation at birth follow the well known ABC's of resuscitation and establishing an open airway is the first step [2]. Secretions are first removed from mouth and then nose with the help of bulb syringes, mucus trap or an electric suction. Mucous syringes are expensive, not disposable and deep suction cannot be done. Adequate negative pressure cannot be developed with mucus traps (Romsons make), while very high pressure can accidentally occur with electric suctions [3]. A simple emergency disposable mucus extractor can easily be improvised from an intravenous drip set for clearing oropharyngeal secretions in the neonates either in Labour Room/Operation Theatre or NICUs.

Parathyroid Hormone-Related Protein (PTHrP) in Tracheal Aspirates of Newborn Infants 1597

PTHrP is expressed in a variety of normal and malignant tissues, including fetal bronchiolar epithelium in a gestationally-dependent manner. PTHrP stimulates phosphatidylcholine synthesis in rat fetal lung explants, and increases the number of lamellar bodies per adult rat alveolar type II cell. Thus PTHrP may play a role in fetal type II alveolar cell maturation and surfactant production. There are currently no studies on PTHrP levels in tracheal aspirates (TAs) of intubated human newborns. Methods We collected TAs from 39 intubated NICU patients within the first 48 hours of life. TAs were collected in a mucus trap and kept frozen prior to analysis. PTHrP was measured by a radioimmunoassay using rabbit antisera to PTHrP 38-64. Total protein (TP) was measured by the Coomassie Blue method. Results Population statistics: average gestational age (GA), 32.2 weeks; average birthweight (BW), 2069 g; and male/female, 17/22. Using the Mann-Whitney test for nonparametric data, differences in PTHrP/TP levels were statistically significant for GA, BW, RDS and gender (<33 weeks gestation)(table). No differences were noted for maternal steroids and diabetes, pregnancy-induced hypertension or bronchopulmonary dysplasia. Conclusion/Speculation PTHrP correlates with and may modulate fetal/neonatal lung maturation.

Investigation of intrapartum clearance of the upper airway in the presence of meconium contaminated amniotic fluid using an animal model.

In order to define as effective a procedure as possible for the intra- and post-partum clearance of the upper airways of meconium contaminated infants, three methods of suction clearance, nasal, oral and combined nasal and oral, were carried out on each of five kittens aged between 17 to 19 weeks. There was an interval of at least one week between each investigation. The animals were anaesthetized with ketamine intramuscularly. The pressure changes during delivery were simulated using a compressed blood pressure cuff around the kittens thorax. During the first minute of thoracic compression Tc 99 labeled synthetic sputum was introduced into both the oro- and nasopharynx, then during the 2nd minute the instilled fluid was removed using a conventional extractor with mucus trap. Solely oral or solely nasal routes were used, suction was carried out for 60 secs, whereas when the combined technique was applied the oral and nasal cavities were cleared for only 30 secs each. At the end at the 2nd minute thoracic compression was released and a deep inspiration occurred. After five minutes the radioactivity remaining after suction was documented using a gamma-camera. We attempted to answer the following questions: How much mucus could be extracted with each different method, and where the remaining amount was later distributed? Nasal suction alone was found to be inefficient; using this route an average of 13% (only an eight of the amount instilled) could be removed. Oral suction led to the recovery of an average of 52% of the material instilled, the combined technique much as 56%. After re-establishment of spontaneous respiration, it could be clearly seen that, independent of the efficacy of the technique used, the majority of the remaining radioactivity (55 relative percent) is localized in the head and neck area. Absolute values are 45% for nasal suction, 26% for oral, and 24% for the combined oro-nasal route. The other part of the remaining radioactivity was found in the lung or in the stomach. It must be pointed out that the aspirate need not be disturbed in both of the parts, both the stomach and the lungs can be solely involved. Five minutes after spontaneous respiration had been resumed the lungs revealed only a centrally distributed radioactivity. This corresponds anatomically to the trachea and major bronchi. The peripheral area of the lungs was free of aspirate at this point in time.(ABSTRACT TRUNCATED AT 400 WORDS)

Bionomics and reproductive cycle of the nematode leptosomatum bacillatum living in the sponge halichondria panicea

Leptosomatum bacillatum (Enoplida: Leptosomatidae) occurs in high densities in the sponge Halichondria panicea. Previously observed fluctuations in modal length suggested an annual reproductive cycle which in this study is confirmed by monthly samplings. Eggs are deposited in July and August and L. bacillatum reaches maturity after one year. Mature females continue growing, their length being season dependent. The bionomics, mucus trap hypothesis and nematode-sponge relationship are discussed.

Directed cytology of the esophagus and stomach: A comparison of 3 rapid collection methods

Directed gastrointestinal cytology complements forceps biopsy and the combination of techniques has greater diagnostic accuracy than either used alone. In an attempt to develop an easy, reliable method of obtaining cytological specimens without prolonging the endoscopic procedure, a comparison of brush cytology and 2 new methods for collecting specimens was made. The new methods utilize the aspiration channel of Olympus endoscopes. The aspirated specimens were collected in a mucus trap attached to the endoscope. These methods included (a) aspiration of exfoliated cells directly from the surface of lesions, and (b) aspiration of material remaining within the biopsy channel after brushing and/or forceps biopsies. Salvage of material remaining within the endoscopic channel provided a useful and rapid method of obtaining cytological specimens.

Mucus trap for tracheal insufflation in newborn infants modified for the administration of oxygen and carbon dioxide

MELVYN BERLIND, M.D., BROOKJ;YN, N. Y. A MODIPICATION of the mucus trap for tracheal insuffiation in the treatment of asphyxiation in the newborn is here presented. The change consists in the addition of an extra . inlet for the purpose of :Hlministering oxygen and <~-arbon dioxide during the insufflation. The percentages used are 95 per cent oxygen and .) per cent carbon dioxide, although straight oxygen might also he used.