Mucosal Penetration Research Articles

Clinical Study of Temporary Anchorage Devices for Orthodontic Treatment

The aim of this retrospective study was to determine factors that might cause complications in use of temporary anchorage devices (TADs) for orthodontic anchorage. We investigated 904 TADs in 455 patients. Clinical diagnoses requiring orthodontic treatment were malocclusion, jaw deformity, various syndromes, cleft lip and palate and impacted teeth. All patients underwent surgery at Tokyo Dental College Chiba Hospital between November 2000 and June 2009. Three kinds of titanium screw of different diameter and length were used: self-drilling mini-screws (Dual Top Autoscrew® and OSAS®), pre-drilling micro-screws (K1 system®) and palatal screws (PIAS®). Mini-plates fixed with 2 or 3 screws (SAS system®) were also used for skeletal anchorage. Patients were aged between 8 and 68 years (25.7±9.8 years). A total of 460 screw-type and 444 plate-type TADs were used. These comprised the following: mini-plates, 444; self-drilling mini-screws, 225; pre-drilling micro-screws, 83; and palatal screws, 152. Each type of implant had a high success rate of over about 90%. Failure rates were as follows: micro-screws, 7%; mini-screws, 6%; palatal implants, 11%; and mini-plates, 6%. Inflammation rate occurring in soft tissue surrounding TADs was follows: plate-type, 7.6%; mini-screws, 1.3%; micro-screws, 0%; and palatal implants, 2.5%. Inflammation frequencies depended on degree of mucosal penetration. Granulation rate in soft tissue surrounding TADs occurred as follows: micro-screws, 5.7%; self-drilling mini-screws, 0%; palatal screws, 0.6%; plate-type, 0.9%. Both plate- and screwtype orthodontic implants showed excellent clinical performance.

P12-16. Biochemical and immunological characterization of the plant-derived candidate HIV-1 mucosal vaccine CTB-MPR

Background One of the targets of a future multi-component vaccine against HIV-1 should be one of the virus' chief mucosal penetration processes, namely epithelial transcytosis. We further reported that fusion proteins based on the membrane proximal region (MPR) of gp41, playing a key role in the transcytotic process, and the mucosal targeting subunit B of cholera toxin (CTB) are successful immunogens eliciting such transcytosis blocking immune responses and that such proteins can be produced in plants

Adsorption of Human Papillomavirus 16 to Live Human Sperm

Human Papillomaviruses (HPVs) are a diverse group of viruses that infect the skin and mucosal tissues of humans. A high-risk subgroup of HPVs is associated with virtually all cases of cervical cancer [1]–[3]. High-risk HPVs are transmitted sexually; however, the exact mechanisms by which sexual contact promotes virus infection remain uncertain. To study this question we asked whether capsids of HPV type 16 (a high-risk HPV) specifically interact with sperm cells. We tested if purified HPV16 virions directly adsorb to live human sperm cells in native semen and in conditions that resemble the female genital tract. We found that HPV16 capsids bind efficiently to two distinct sites at the equatorial region of the sperm head surface. Moreover, we observed that the interaction of virus with sperm can be reduced by two HPV infection inhibitors, heparin and carrageenan. Our findings suggest that 1) sperm cells may serve as motile carriers that promote virus dispersal and mucosal penetration, and 2) blocking interactions between HPV16 and sperm cells may be an important strategy for the development of antiviral therapies.

Reciprocal Interactions between Commensal Bacteria and γδ Intraepithelial Lymphocytes during Mucosal Injury

The intestinal mucosal surface is in direct contact with a vast beneficial microbiota. The symbiotic nature of this relationship is threatened when the surface epithelium is injured, yet little is known about how mucosal surfaces maintain homeostasis with commensal microbes following damage. Gammadelta intraepithelial lymphocytes (gammadelta IEL) reside at the gut epithelial surface, where they stimulate mucosal healing following acute injury. A genome-wide analysis of the gammadelta IEL response to dextran sulfate sodium-induced colonic damage revealed induction of a complex transcriptional program, including coordinate regulation of cytoprotective, immunomodulatory, and antibacterial factors. Studies in germfree mice demonstrated that commensal microbiota regulate key components of this transcriptional program, thus revealing a dialogue between commensal bacteria and gammadelta IEL in injured epithelia. Analysis of TCRdelta-deficient mice indicated that gammadelta T cells are essential for controlling mucosal penetration of commensal bacteria immediately following dextran sulfate sodium-induced damage, suggesting that a key function of gammadelta IEL is to maintain host-microbial homeostasis following acute mucosal injury. Taken together, these findings disclose a reciprocal relationship between gammadelta T cells and intestinal microbiota that promotes beneficial host-microbial relationships in the intestine.

Editorial Commentary:Nongonococcal Urethritis and Antibiotic‐ResistantMycoplasma genitaliumInfection

The finding of Mycoplasma genitalium in the urethra of men with nongonococcal urethritis (NGU) [1, 2] and its later unequivocal and significant association, not only with NGU as a whole, but also with chlamydia-negative NGU [3], has at least partially filled the void in our understanding of the etiology of NGU in men. Although tetracyclines (in particular, doxycycline) were the antibiotics of choice for the treatment of NGU before the finding of M. genitalium, it has become apparent that they are not the antibiotics of choice for M. genitalium-associated urethritis. Indeed, this mycoplasma was often found to persist in the urethra of men treated with tetracyclines [4, 5], and it became clear that tetracycline treatment was responsible for some, if not all, cases of persistent or chronic NGU. Fortunately, it seemed, azithromycin was available for the treatment of Chlamydia trachomatis infection; azithromycin was more active in vitro than the tetracyclines, had superior mucosal cell penetration, and could be given effectively as a single dose. When azithromycin was given to M. genitaliumpositive men with urethritis, the organisms were eliminated from the genital tracts of almost all patients; the patients responded accordingly, without the development of chronic disease [6], In hindsight, this should not have been surprising, because the in vitro activity of tetracylines against M. genitalium is poor, and the macrolides have far greater activity, with azithromycin being the most effective [7]. Interestingly, a similar antibiotic profile is seen with Mycoplasma pneumoniaey which is closely related antigenically to M. genitalium. Thus, the notion that NGU of chlamydial or mycoplasmal etiology can be dealt with by a single antibiotic, namely azithromycin, has had considerable clinical appeal. Admittedly, Ureaplasma species are not very susceptible to azithromycin; however, that aside, our understanding of the etiology of NGU and the development of a rational treatment for the disease had progressed. Now, we learn that strains of M. genitalium have developed (and, doubtless, continue to develop) resistance to azithromycin through mutations in region V of the 23S ribosomal RNA gene [8]. This is a potentially serious matter because of the possibility that extensive use of single-dose azithromycin for treatment of G trachomatis or for presumptive treatment of NGU might lead to the development of widespread resistance in M. genitalium strains and, therefore, to worsening disease in both men and women. What measures might be taken to prevent an increase in the prevalence of resistance to azithromycin? Clinicians should realize that single-dose therapy for NGU may create the problem of resistance and that spreading the dosage over several days may overcome the problem. If this is not effective and there is evidence that chronic disease is developing, thought should be given to administering a course of moxifloxacin [9], which has potent activity against M. genitalium [10]. Hopefully, in the future, most clinicians will be able to rely on the assistance of laboratory analysis, which will enable them to make a sensible choice of antibiotic and dosage. The treatment of NGU in patients who are also HIV positive is also uncharted territory. There is some evidence that such subjects are more susceptible to infection due to M. genitalium than are individuals who are HIV negative [11]. Furthermore, animal experiments have clearly shown that a fully functioning immune system is required for the elimination of mycoplasmas (as opposed to simply suppression of their growth) after antibiotic therapy [12]. It remains to be seen whether this is another hurdle that has to be faced in the Received 8 September 2008; accepted 8 September 2008; electronically published 6 November 2008. Reprints or correspondence: Dr. David Taylor-Robinson, 6 Vache Mews. Vache Ln., Chalfont St. Giles. Bucks HP8 4UT, United Kingdom (dtr@vache99.freeserve.co.uk). Clinical Infectious Diseases 2008; 47:1 554-5 © 2008 by the Infectious Diseases Society of America. All rights reserved. 1 058-4838/2008/471 2-0009$1 5.00 D0I: 10.1086/593189

Mucosal penetration primes Vibrio cholerae for host colonization by repressing quorum sensing

To successfully infect a host and cause the diarrheal disease cholera, Vibrio cholerae must penetrate the intestinal mucosal layer and express virulence genes. Previous studies have demonstrated that the transcriptional regulator HapR, which is part of the quorum sensing network in V. cholerae, represses the expression of virulence genes. Here, we show that hapR expression is also modulated by the regulatory network that governs flagellar assembly. Specifically, FliA, which is the alternative sigma-factor (sigma(28)) that activates late-class flagellin genes in V. cholerae, represses hapR expression. In addition, we show that mucin penetration by V. cholerae is sufficient to break flagella and so cause the secretion of FlgM, the anti-sigma factor that inhibits FliA activity. During initial colonization of host intestinal tissue, hapR expression is repressed because of low cell density. However, full repression of hapR expression does not occur in fliA mutants, which results in attenuated colonization. Our results suggest that V. cholerae uses flagellar machinery to sense particular intestinal signals before colonization and enhance the expression of virulence genes by modulating the output of quorum sensing signaling.

A Virulent Response to Losing Your Tail

The bacterium Vibrio cholerae (which causes the diarrheal disease cholera) secretes and detects signals that lead to the transcriptional repression of virulence genes by means of the regulator HapR; thus, its expression of virulence factors decreases with increased population density. Liu et al . used an antibiotic-coupled transposon screen to identify signals that might regulate virulence through this quorum-sensing pathway. Intriguingly, mutation of various genes involved in biosynthesis of V. cholerae ’s flagellum decreased HapR activity and increased the production of virulence factors. Deletion of flgD , which encodes a flagellar rod protein, inhibited transcription of a hapR transcriptional reporter and that of a reporter activated by HapR, but promoted transcription of a reporter inhibited by HapR as well as production of virulence factors. Constitutive activation of the gene encoding FliA, which is involved in the activation of some flagellar genes, also promoted virulence factor production. Noting that FliA activity increases with the secretion of its inhibitor FlgM through the flagellar export apparatus, the authors determined that FlgM concentration was greater in supernatants from flgD mutant cultures than in those from wild-type cultures. Moreover, the effects of the flgD mutant on hapR expression were mediated through FliA. V. cholerae must traverse a layer of mucus to colonize intestinal epithelial cells, and both flagellar staining and electron microscopic analysis revealed that more than 80% of wild-type V. cholerae lost their flagellae while swimming through 1% mucin. The concentration of FlgM was higher in supernatants of cultures containing mucin, and hapR expression was decreased in mucin-exposed bacteria. Thus, the authors suggest that signals encountered en route to the epithelial cells may enable V. cholerae to jettison HapR-mediated repression of virulence at precisely the right time and place. Z. Liu, T. Miyashiro, A. Tsou, A. Hsiao, M. Goulian, J. Zhu, Mucosal penetration primes Vibrio cholerae for host colonization by repressing quorum sensing. Proc. Natl. Acad. Sci. U.S.A. 105 , 9769-9774 (2008). [Abstract] [Full Text]

Ezrin is a key element in the human vagina

Objective The vagina is a complex tubular structure that has reproductive, support and barrier functions. These depend on the cytoarchitecture of the vaginal cells, which is controlled by key proteins. Cytoskeletal proteins determine cell polarity and membrane specializations by integrating the actin cytoskeleton with cell membranes. This integration is the domain of cytoskeletal proteins including the MERM protein family (moesin-ezrin-radixin-Merlin). Nothing is known about the cyto-localization of the MERM's in the vaginal epithelium or how it influences the cytoarchitecture of the vaginal epithelium and stroma. Design Full-thickness human vaginal fornix samples were obtained from 20 normal human specimens obtained at surgery for pelvic relaxation. Light- and electron microscopical immunohistochemistry (IHC) were used to identify and study activation and cellular localization of immuno-reactive-ezrin (ir-ezrin), a prototypical MERM. Results Ir-ezrin was identified in the stratified squamous vaginal epithelium and connective tissue (fibroblasts, blood vessels and leucocytes). “H” scoring indicated that ir-ezrin staining is denser in the vaginal epithelium than in other layers, that the ir-ezrin staining was associated with increased keratinization and with the size of the tight junctions ( p < 0.01). Both the amounts and localization of ir-ezrin were associated with high levels of estrogen, identified by the menstrual history and keratinization of the superficial vaginal epithelium. The density of stromal ir-ezrin was increased in the presence of dense epithelial keratinization. Immuno-reactive-ezrin staining was most pronounced near the cell membranes of both keratinized and non-keratinized epithelium, indicating that ezrin activation (unfolding and movement to the membrane) had occurred. Ultra-structural examination of the epithelium showed intra-cellular ir-ezrin to be localized to junctional complexes that have been associated with decreased mucosal penetration by microorganisms. Ir-ezrin was widely distributed throughout stromal fibro-muscular cell, vessels and immunocytes. Conclusions MERM's, represented by ezrin, are widely present in the vaginal wall. This has implications for the strength and resilience of this tubular structure and may be the case in other internal genital tissues. Ezrin's localization and association with cell specializations indicate that in the vagina, as in other tissues, ezrin likely modulates vaginal cell–cell interactions including the changing vaginal cellular interface with the external environment, the regulation of the elasticity of the vagina, and the regulation of microbial and chemical traffic that determine the pH and microbial environment of the vagina. In other work we have shown that ezrin expression is induced by estradiol. The increase of ir-ezrin staining during the appearance of keratinization and maturation of the vaginal cytology indicates that estrogen may regulate vaginal ezrin and thereby the properties of the vaginal wall and epithelium.

This Month in Gastroenterology

This Month in Gastroenterology

Ocular Surface Reconstruction With Combination of Cultivated Autologous Oral Mucosal Epithelial Transplantation and Penetrating Keratoplasty

To report an assessment of the two-step surgical combination of cultivated autologous oral mucosal epithelial transplantation (COMET) and penetrating keratoplasty (PKP) used to treat patients with severe limbal deficiency disorders, and to investigate the keratin expression patterns of transplanted surviving oral mucosal epithelium. Observational case series. Two patients with Stevens-Johnson syndrome and chemical eye injury were treated by COMET followed, approximately six months later, by a PKP triple procedure. In the course of a mean follow-up period of 22.5 months, their clinical outcomes and the efficacy of this two-step surgical procedure were assessed. In addition, the keratin expression in corneal buttons excised during PKP were immunohistochemically examined to characterize the oral mucosal epithelium that survived ectopically on the cornea. In vivo laser confocal microscopy was used to investigate the structure of the epithelium on the corneal grafts. The ocular surfaces were successfully reconstructed with cultivated autologous oral mucosal epithelial sheets and PKP. No clinical complications, such as persistent epithelial defects, rejections, or recurrence of cicatrization, were encountered. Postoperative best-corrected visual acuity was 20/125 in one patient and 20/100 in the other. The surviving oral mucosal epithelium, distinguished by its fluorescence pattern, consisted of an irregular, nonkeratinized, stratified epithelium without goblet cells. Immunohistochemical study demonstrated that K3, but not K12, was expressed in the transplanted cultivated oral mucosal epithelium that was similar to oral mucosal tissue. In vivo, the epithelial structure and cell density in the basal cell layer of the corneal grafts were similar to normal cornea. This study presents a two-step surgical approach to treat severely scarred ocular surfaces by means of a combination of COMET and PKP. Clinical outcomes suggest that this treatment may be beneficial for the maintenance of the reconstructed ocular surface by providing oral mucosal epithelium around the corneal graft.

High Rate of Lymph-Node Metastasis in Submucosal Esophageal Squamous-Cell Carcinomas and Adenocarcinomas

The application of endoscopic mucosectomy in early esophageal cancer is limited by the presence of lymph-node metastasis. The aim of this prospective study was to analyze the rate of lymph-node involvement relative to the depth of mucosal or submucosal tumor penetration, comparing squamous-cell carcinomas and adenocarcinomas. A total of 60 patients with pT1 esophageal cancer--24 with squamous-cell carcinomas (SCCs) and 36 with adenocarcinomas--were treated with transthoracic en-bloc esophagectomy with two-field lymphadenectomy (n = 50) or transhiatal esophageal resection (n = 10). An average of 30 lymph nodes were examined, and the following characteristics were evaluated: histology, mucosal infiltration, depth of submucosal wall infiltration in three thirds (sm1, sm2, sm3), grading, resection category, ratio of metastatic to resected lymph nodes, and locations of metastatic nodes. The rates of lymph-node metastasis were 0% for the 16 mucosal carcinomas and 45% for the 44 submucosal carcinomas (P < 0.01). There were no significant differences in the extent of lymph-node involvement between submucosal adenocarcinomas (41%) and submucosal SCCs (50%). Sm1 carcinomas were associated with a lower rate of lymph-node metastasis (SCCs 33%, adenocarcinomas 22%) than sm3 carcinomas (SCCs 69%, adenocarcinomas 78%). Two patients (9%) with submucosal SCCs and five patients (23%) with submucosal adenocarcinomas were classified as having stage pM1 lymph. The average lymph-node ratio in patients with pN1 was 0.13 for adenocarcinomas and 0.1 for SCCs (difference not significant). In the multivariate analysis, the parameters mucosal vs. submucosal (P < 0.01) and G1/G2 vs. G3 (P < 0.05) showed a significant impact in relation to metastatic lymph nodes. The most important factor for predicting lymph-node metastasis in early esophageal cancer is the presence of submucosal infiltration. Early adenocarcinomas and SCCs do not differ with regard to their rate of lymphatic involvement. The rate of lymph-node metastasis increases with the depth of submucosal infiltration, but metastases can already occur in sm1 lesions. Submucosal infiltration is a contraindication for endoscopic mucosectomy. Limited surgical procedures without adequate lymphadenectomy do not appear to be appropriate in the treatment of patients with submucosal esophageal carcinomas.

Factors Influencing the Discomfort of Intraoral Needle Penetration

This study with 24 volunteers compared the discomfort produced by needle penetration in different parts of the palatal mucosa. In addition, comparing a fresh needle to one that was used for a previous penetration in the same patient, we assessed the influence of the status of the needle on insertion discomfort during buccal mucosal penetration. The results showed that needle penetration in the anterior hard palate was more uncomfortable than in the posterior palate. Although men could not differentiate between fresh and used needles for a second buccal mucosal penetration, women reported a significant increase in discomfort with used needles.

Optimisation of a lipid based oral delivery system containing A/Panama influenza haemagglutinin

Vaccine antigens administered by the oral route are often degraded by gastric secretions during gastrointestinal transit. This necessitates larger and more frequent doses of antigen for vaccination. A delivery system, which overcomes this, is a lipid vesicle containing bile salts (bilosome), which prevents antigen degradation and enhances mucosal penetration. The effect of bilosome formulation modification on vaccine transit efficacy across the mucosa was determined. Specific antibody levels were assessed by end-point titre ELISA and the subclasses determined. Significant IgG1 titres were induced when the protein loading was doubled from 15 to 30 μg ( P=0.009) and was equivalent to antigen administration by the subcutaneous route. No IgG2a was induced, indicating the generation of a T H2 response. Significant mucosal IgA levels were also observed with this treatment group ( P=0.05).

Keeping Friends at Bay

The commensal bacteria of the intestine share some molecular signatures with pathogenic bacteria but do not normally stimulate intestinal inflammation. Macpherson and Uhr (see the Perspective by Kraehenbuhl and Corbett) show that commensal strains of bacteria selectively stimulate intestinal B cells to produce immunoglobulin A (IgA) antibodies. Commensal bacteria invade and survive within dendritic cells, which travel to inductive sites of the mucosal lymphoid system. This IgA-mediated inhibition of mucosal penetration by commensal bacteria may help the intestine avoid unwanted inflammatory responses. A. J. Macpherson, T. Uhr, Induction of protective IgA by intestinal dendritic cells carrying commensal bacteria. Science 303 , 1662-1665 (2004). [Abstract] [Full Text] J.-P. Kraehenbuhl, M. Corbett, Keeping the gut microflora at bay. Science 303 , 1624-1625 (2004). [Summary] [Full Text]

Induction of protective IgA by intestinal dendritic cells carrying commensal bacteria.

The enormous number of commensal bacteria in the lower intestine of vertebrates share abundant molecular patterns used for innate immune recognition of pathogenic bacteria. We show that, even though commensals are rapidly killed by macrophages, intestinal dendritic cells (DCs) can retain small numbers of live commensals for several days. This allows DCs to selectively induce IgA, which helps protect against mucosal penetration by commensals. The commensal-loaded DCs are restricted to the mucosal immune compartment by the mesenteric lymph nodes, which ensures that immune responses to commensal bacteria are induced locally, without potentially damaging systemic immune responses.

Linezolid versus teicoplanin in the treatment of Gram-positive infections in the critically ill: a randomized, double-blind, multicentre study

Linezolid, the only commercially available oxazolidinone, is indicated for the treatment of Gram-positive infections, although little has been published specifically on its use in the critically ill. A randomized, prospective study was therefore performed to compare linezolid with the glycopeptide antibiotic, teicoplanin, for the treatment of suspected or proven Gram-positive infections in an intensive care population. Using a double-blind, double-dummy, prospective design, patients were randomized to (i) intravenous linezolid (600 mg/12 h) plus teicoplanin dummy [one dose/12 h for three doses then every 24 h intravenously (iv)] or (ii) teicoplanin (400 mg/12 h for three doses then 400 mg/24 h iv) plus linezolid dummy (one dose/12 h iv). Other antibiotics were used in combination with the trial agents in empirical treatment. Clinical and microbiological assessments were made daily in the first week, and at 8 and 21 days after treatment. One hundred patients received linezolid plus placebo-teicoplanin, whereas 102 received teicoplanin plus placebo-linezolid. Population baseline characteristics were similar in both groups. At end of treatment, clinical success [71 (78.9%) linezolid versus 67 (72.8%) teicoplanin] and microbiological success [49 (70.0%) versus 45 (66.2%)] rates were similar, as were adverse effects, intensive care unit mortality, and success rates at short- and long-term follow-up. Linezolid was superior at initial clearance of methicillin-resistant Staphylococcus aureus (MRSA) colonization (end of treatment, 51.1% versus 18.6%, P = 0.002). Two MRSA isolates showed reduced susceptibility to teicoplanin. Linezolid has similar safety and efficacy to teicoplanin in treating Gram-positive infections in the critically ill. Short-term MRSA clearance achieved with linezolid suggests better skin and mucosal penetration.

Effects of Surfactants on Gel Behavior

The recent advances in the design and synthesis of new polymeric systems have opened a wide range of possibilities for the use of gels as drug dosage forms. These systems are able to act not only as simple reservoirs, but also as controlled-release systems and/or targeting agents for site-specific delivery. Applications of gels are determined by their drug-loading capability, rheological properties, and the mechanisms and kinetics of drug release. The incorporation of small proportions of surfactants, which are able to promote or hinder intra- or interchain polymeric bonds, may modify these properties and be a useful tool for developing gel-based dosage forms. Polymers and surfactants may interact, depending on their chemical structure, through ionic, hydrophobic and hydrogen-bonding mechanisms. The strength of the interaction is strongly affected by pH, ionic strength and presence of other substances, and physiological changes in these variables. These physiologic parameters affect the performance of polymer/surfactant gels as drug delivery systems. Surfactants may also promote cutaneous or mucosal drug penetration. Drug release processes from polymer/surfactant gels depend on the microstructure of the gel and the drug ‘state’ in the system. The drug can be: solubilized in water without interacting with any of the components; electrostatically or hydrophobically bound to the polymer; or solubilized inside micelles or polymer/surfactant aggregates. Interactions between surface-active drugs and polymers should also be taken into account because of their important repercussions on gel behavior. Finally, polymer/surfactant systems have a great potential for gene therapy, and some polymers that are able to interact with natural surfactants can be used as trap systems of bile salts for controlling the physiological levels of cholesterol.

Characterization of the properties of human- and dairy-derived probiotics for prevention of infectious diseases in fish.

The present study aimed to investigate the potential probiotic properties of six lactic acid bacteria (LAB) intended for human use, Lactobacillus rhamnosus ATCC 53103, Lactobacillus casei Shirota, Lactobacillus bulgaricus, L. rhamnosus LC 705, Bifidobacterium lactis Bb12, and Lactobacillus johnsonii La1, and one for animal use, Enterococcus faecium Tehobak, for use as a fish probiotic. The strains for human use were specifically chosen since they are known to be safe for human use, which is of major importance because the fish are meant for human consumption. The selection was carried out by five different methods: mucosal adhesion, mucosal penetration, inhibition of pathogen growth and adhesion, and resistance to fish bile. The adhesion abilities of the seven LAB and three fish pathogens, Vibrio anguillarum, Aeromonas salmonicida, and Flavobacterium psychrophilum, were determined to mucus from five different sites on the surface or in the gut of rainbow trout. Five of the tested LAB strains showed considerable adhesion to different fish mucus types (14 to 26% of the added bacteria). Despite their adhesive character, the LAB strains were not able to inhibit the mucus binding of A. salmonicida. Coculture experiments showed significant inhibition of growth of A. salmonicida, which was mediated by competition for nutrients rather than secretion of inhibitory substances by the probiotic bacteria as measured in spent culture liquid. All LAB except L. casei Shirota showed tolerance against fish bile. L. rhamnosus ATCC 53103 and L. bulgaricus were found to penetrate fish mucus better than other probiotic bacteria. Based on bile resistance, mucus adhesion, mucus penetration, and suppression of fish pathogen growth, L. rhamnosus ATCC 53103 and L. bulgaricus can be considered for future in vivo challenge studies in fish as a novel and safe treatment in aquaculture.

A bleeding gastric ulcer on a vanishing tumor caused by anisakiasis

Gastric anisakiasis is accompanied by intermittent upper abdominal pain due to gastric mucosal penetration of anisakis larvae ingested with raw fish. Chest roentgenograms demonstrate round and oval tumor-like shadows with localized interlobular pleural fluid collections that disappear in a relatively short time with improvement of symptoms.1 As well, there have been reports of submucosal tumors in the stomach that disappeared within a short period of time. A relationship between anisakiasis and vanishing tumor has thus been suggested.

Coinfection with influenza B virus does not affect association of Neisseria meningitidis with human nasopharyngeal mucosa in organ culture.

There is an epidemiological association between influenza virus infection and meningococcal disease. Proposed mechanisms are the destruction of the normal epithelial barrier function of the upper respiratory tract by influenza virus or the expression of human or viral surface-exposed proteins that enhance bacterial adherence and/or invasion. To test these hypotheses, human nasopharyngeal mucosa specimens from a total of 19 individual donors were successfully infected with influenza B virus and then inoculated with serogroup B Neisseria meningitidis. Subsequent bacterial association with the epithelial surface was measured in three separate series of experiments by using transmission electron microscopy (n = 6), scanning electron microscopy (n = 6), and counting of viable bacteria within homogenates of explants (n = 7). Penetration of the mucosa was estimated by measuring the count of viable bacteria recovered from explants after exposure to sodium taurocholate. Bacterial association with the surface of explants was time dependent over 24 h of superinfection. Influenza virus did not positively or negatively influence bacterial attachment to or penetration of explant mucosa compared to those of uninfected controls, even when the period of preincubation with virus was extended to 7 days. When proteins were purified from mucosal epithelium and immobilized on nitrocellulose membranes, N. meningitidis attached predominantly to bands corresponding to proteins of 210 and 130 kDa. In the presence of influenza virus infection, these proteins were gradually lost over the course of 72 h. In conclusion, influenza B virus did not increase association of serogroup B N. meningitidis with human nasopharyngeal mucosa.