A diffusible signal factor of the intestine dictates Salmonella invasion through its direct control of the virulence activator HilD.

Successful intestinal infection by Salmonella requires optimized invasion of the gut epithelium, a function that is energetically costly. Salmonella have therefore evolved to intricately regulate the expression of their virulence determinants by utilizing specific environmental cues. Here we show that a powerful repressor of Salmonella invasion, a cis-2 unsaturated long chain fatty acid, is present in the murine large intestine. Originally identified in Xylella fastidiosa as a diffusible signal factor for quorum sensing, this fatty acid directly interacts with HilD, the master transcriptional regulator of Salmonella, and prevents hilA activation, thus inhibiting Salmonella invasion. We further identify the fatty acid binding region of HilD and show it to be selective and biased in favour of signal factors with a cis-2 unsaturation over other intestinal fatty acids. Single mutation of specific HilD amino acids to alanine prevented fatty acid binding, thereby alleviating their repressive effect on invasion. Together, these results highlight an exceedingly sensitive mechanism used by Salmonella to colonize its host by detecting and exploiting specific molecules present within the complex intestinal environment.

Crystal structure of bacterial cytotoxic necrotizing factor CNFY reveals molecular building blocks for intoxication.

Cytotoxic necrotizing factors (CNFs) are bacterial single-chain exotoxins that modulate cytokinetic/oncogenic and inflammatory processes through activation of host cell Rho GTPases. To achieve this, they are secreted, bind surface receptors to induce endocytosis and translocate a catalytic unit into the cytosol to intoxicate host cells. A three-dimensional structure that provides insight into the underlying mechanisms is still lacking. Here, we determined the crystal structure of full-length Yersinia pseudotuberculosis CNFY . CNFY consists of five domains (D1-D5), and by integrating structural and functional data, we demonstrate that D1-3 act as export and translocation module for the catalytic unit (D4-5) and for a fused ß-lactamase reporter protein. We further found that D4, which possesses structural similarity to ADP-ribosyl transferases, but had no equivalent catalytic activity, changed its position to interact extensively with D5 in the crystal structure of the free D4-5 fragment. This liberates D5 from a semi-blocked conformation in full-length CNFY , leading to higher deamidation activity. Finally, we identify CNF translocation modules in several uncharacterized fusion proteins, which suggests their usability as a broad-specificity protein delivery tool.

Helicobacter pylori gastric infection in patients with laryngeal cancer and chronic laryngitis.

BACKGROUND: The purpose of this study was to investigate the pathohistological status of mucous lining infected with Helicobacte pylori as the possible cause of chronic laryngitis and laryngeal carcinoma. MATERIALS AND METHODS: The prospective examination included 51 patients suffering from planocellular laryngeal cancer and 26 examinees suffering from chronic laryngitis. The examinees and the control group were subjected to esophagogastroduodenoscopy which described the local status of the esophagus and stomach. Two biopsy samplings are taken from the stomach antrum and corpus. One part of the biopsies was colored using the histological technique used in the pathohistological detection of H. pylori, while the other part was incorporated in paraffin cubes where the H. Pylori gene expression was determined using the deparaffinization and PCR method DNA isolation. RESULTS: In the group of examinees suffering from laryngeal tumor, there were a higher number of patients suffering also from chronic gastritis (32/51) than in the other group, suffering from chronic laryngitis (9/26). In the chronic laryngitis group, there were more examinees with acute gastritis (12/26) than in the examined group (11/51). The difference is statistically significant (p = 0.0457). CONCLUSION: Chronic gastritis and H. pylori infection are risk factors for laryngeal carcinoma formation; therefore, acute gastritis with helicobacter pylori infection must be immediately treated to not let infection to become chronic.

Shock séptico por Leptotrichia buccalis en paciente neutropénico por quimioterapia / Septic shock caused by Leptotrichia buccalis in a neutropenic patient secondary to chemotherapy

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Recurrent bacterial translocation from gut and sepsis in Head and neck cancer patients and its prevention by probiotics.

Head and neck cancers are the 6th most common cancer type in human malignant tumors and treated with chemoradiotherapy and surgery. Chemotherapy during these treatment modalities leads to damage of intestinal epithelial barriers and results in translocation of intestinal bacteria in bloodstream through invasion in these damaged regions. In this report, we report two cases of hypopharyngeal cancer patients, both of whom received chemotherapy before surgery. The patients demonstrated repeated sepsis before and after surgery, supporting translocation of intestinal bacteria. Proper continuous probiotic use prevented proliferation and intestinal bacterial translocation. Hypothesis of bacterial translocation and prevention by probiotics are discussed.

Presence of Helicobacter Pylori in the Stomach and Laryngeal Mucosal Linings in Patients with Laryngeal Cancer.

Helicobacter (H.) pylori is the cause of one of the most common chronic bacterial infections in humans. Risk factors for the development of laryngeal cancer are cigarette smoke, alcohol, and human papillomavirus. Several papers report on H. pylori isolated in tooth plaque, saliva, middle ear and sinuses. Many articles describe the presence of H. pylori in laryngeal cancer cases, however, without noting the possible source of infection, i.e. stomach or oral cavity. The aim of this study was to determine which patients and to what extent simultaneously developed H. pylori colonization in the stomach and the larynx. Prospective examinations were performed in 51 patients with laryngeal squamous cell carcinoma. The study group included patients with laryngeal squamous cell carcinoma histopathologically confirmed by two independent pathologists. The patients underwent fiber esophagogastroduodenoscopy with tumor tissue biopsy. Laryngeal and gastric biopsies were ex-amined by histologic staining technique for histopathologic detection of H. pylori and with DNA analyses using the standardized fluorescent ABI Helicobacter plus-minus PCR assay. Laryngeal car-cinoma patients showed positive H. pylori test results simultaneously in the laryngeal and stomach areas, implying H. pylori transmission from the stomach to the laryngeal area. In addition, H. pylori positive test results along with negative H. pylori results in the stomach region were also recorded, suggesting a possible bacteria migration from the oral cavity. In conclusion, H. pylori was found in the area of laryngeal carcinoma, and its migration appeared likely to occur both upwards (from the stomach to the mouth) and downwards (from the oral cavity to the stomach).

A tricyclic pyrrolobenzodiazepine produced by Klebsiella oxytoca is associated with cytotoxicity in antibiotic-associated hemorrhagic colitis.

Cytotoxin-producing Klebsiella oxytoca is the causative agent of antibiotic-associated hemorrhagic colitis (AAHC). Recently, the cytotoxin associated with AAHC was identified as tilivalline, a known pentacyclic pyrrolobenzodiazepine (PBD) metabolite produced by K. oxytoca Although this assertion of tilivalline's role in AAHC is supported by evidence from animal experiments, some key aspects of this finding appear to be incompatible with toxicity mechanisms of known PBD toxins. We therefore hypothesized that K. oxytoca may produce some other uncharacterized cytotoxins. To address this question, we investigated whether tilivalline alone is indeed necessary and sufficient to induce cytotoxicity or whether K. oxytoca also produces other cytotoxins. LC-MS- and NMR-based metabolomic analyses revealed the presence of an abundant tricyclic PBD, provisionally designated kleboxymycin, in the supernatant of toxigenic K. oxytoca strains. Moreover, by generating multiple mutants with gene deletions affecting tilivalline biosynthesis, we show that a tryptophanase-deficient, tilivalline-negative K. oxytoca mutant induced cytotoxicity in vitro similar to tilivalline-positive K. oxytoca strains. Furthermore, synthetic kleboxymycin exhibited greater than 9-fold higher cytotoxicity than tilivalline in TC50 cell culture assays. We also found that the biosynthetic pathways for kleboxymycin and tilivalline appear to overlap, as tilivalline is an indole derivative of kleboxymycin. In summary, our results indicate that tilivalline is not essential for inducing cytotoxicity observed in K. oxytoca-associated AAHC and that kleboxymycin is a tilivalline-related bacterial metabolite with even higher cytotoxicity.

Composition and abundance of microbiota in the pharynx in patients with laryngeal carcinoma and vocal cord polyps.

The pharynx is an important site of microbiota colonization, but the bacterial populations at this site have been relatively unexplored by culture-independent approaches. The aim of this study was to characterize the microbiota structure of the pharynx. Pyrosequencing of 16S rRNA gene libraries was used to characterize the pharyngeal microbiota using swab samples from 68 subjects with laryngeal cancer and 28 subjects with vocal cord polyps. Overall, the major phylum was Firmicutes, with Streptococcus as the predominant genus in the pharyngeal communities. Nine core operational taxonomic units detected from Streptococcus, Fusobacterium, Prevotella, Granulicatella, and Veillonella accounted for 21.3% of the total sequences detected. However, there was no difference in bacterial communities in the pharynx from patients with laryngeal cancer and vocal cord polyps. The relative abundance of Firmicutes was inversely correlated with Fusobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes. The correlation was evident at the genus level, and the relative abundance of Streptococcus was inversely associated with Fusobacterium, Leptotrichia, Neisseria, Actinomyces, and Prevotella. This study presented a profile for the overall structure of the microbiota in pharyngeal swab samples. Inverse correlations were found between Streptococcus and other bacterial communities, suggesting that potential antagonism may exist among pharyngeal microbiota.

Alterations of microbiota structure in the larynx relevant to laryngeal carcinoma.

The microbial communities that inhabit the laryngeal mucosa build stable microenvironments and have the potential to influence the health of the human throat. However, the associations between the microbiota structure and laryngeal carcinoma remain uncertain. Here, we explored this question by comparing the laryngeal microbiota structure in laryngeal cancer patients with that in control subjects with vocal cord polyps through high-throughput pyrosequencing. Overall, the genera Streptococcus, Fusobacterium, and Prevotella were prevalent bacterial populations in the laryngeal niche. Tumor tissue samples and normal tissues adjacent to the tumor sites (NATs) were collected from 31 laryngeal cancer patients, and the bacterial communities in laryngeal cancer patients were compared with control samples from 32 subjects. A comparison of the laryngeal communities in the tumor tissues and the NATs showed higher α-diversity in cancer patients than in control subjects, and the relative abundances of seven bacterial genera differed among the three groups of samples. Furthermore, the relative abundances of ten bacterial genera in laryngeal cancer patients differed substantially from those in control subjects. These findings indicate that the laryngeal microbiota profiles are altered in laryngeal cancer patients, suggesting that a disturbance of the microbiota structure might be relevant to laryngeal cancer.

UreA and cagA genes of Helicobacter pylori in Egyptian patients with laryngeal squamous cell carcinoma and benign laryngeal polyps: a cohort study.

This work aims to estimate the prevalence of Helicobacter pylori ureA gene and evaluate cagA gene-positive strains in both patients of laryngeal squamous cell carcinoma (LSCC) and those with benign laryngeal polyps. This study included 49 patients confirmed pathologically to have LSCC and 15 patients with benign laryngeal polyps over a period from June 2013 to March 2015. Samples of laryngeal tissue were collected during direct laryngoscope under general anesthesia to be pathologically evaluated followed by analysis for H. pylori detection. Each laryngeal tissue sample was divided into three parts; one for bacteriological examination, the second for pathological examination and the third for PCR to detect both ureA and cagA genes. Out of 49 LSCC samples, 31 (64.6 %) was positive for ureA by PCR. Out of them, 29 samples (93.5 %) were cagA positive. Only three cases (20 %) of the benign laryngeal polyp were ureA positive by PCR and one of them was cagA positive by PCR. By the bacteriological culture, only eight samples (25.8 %) gave growth. All of them were ureA positive and only seven of them were cagA positive. There was a significant association between presence of H. pylori and LSCC as compared to benign laryngeal polyp which may contribute in the pathogenesis of laryngeal carcinoma. These results should be confirmed by further studies over larger number of cases.

Isolation and identification of Candida species in patients with orogastric cancer: susceptibility to antifungal drugs, attributes of virulence in vitro and immune response phenotype.

BACKGROUND: Because of the inherent immunosuppression of cancer patients opportunistic infections by Candida spp, occur frequently. This study aimed to identify Candida species in the oral mucosa of 59 patients with orogastric cancer (OGC) and to analyze the immunological phenotype of these patients. METHODS: The yeasts were identified by MALDI-TOF mass spectrometry (MS). For all isolates, we performed phospholipases and proteinases assays, in vitro adherence to buccal epithelial cells (BEC), minimum inhibitory concentration of antifungal drugs and determined the cytokine profile by Cytometric Bead Array flow citometry assay. RESULTS: C. albicans was the most prevalent species in OGC patients (51.6 %) and control group (66.7 %). Candida spp. strains isolated from OGC patients exhibited better adherence to BEC (p = 0.05) than did the control group. Phospholipases production by Candida strains from OGC patients was lower (51.6 %) than in the control group (61.9 %). Proteinases were detected in 41.9 % and 4.8 % of the yeasts from OGC patients and control group, respectively. Significant differences were found in the serum of OGC patients compared to the control group for IL-2, IL-10, TNF-α, IFN-γ and IL-17. CONCLUSIONS: The results of this work suggest increased virulence of yeasts isolated from OGC patients and, that this may interfere with the immune phenotype.

Association between helicobacter pylori infection and carcinoma of the larynx or pharynx.

BACKGROUND: Infection with Helicobacter pylori (H. pylori) plays a role in the development of gastric carcinoma. However, there is controversy as to whether H. pylori infection increases laryngeal or pharyngeal cancers. METHODS: We managed a systematic review of researches related to H. pylori infection in laryngeal or pharyngeal carcinomas, distributed up to December 2014. Odds ratios (ORs) and 95% confidence intervals (CIs) were assessed by random effects models or according to heterogeneity I(2) . RESULTS: Eleven studies were involved in the meta-analysis. Overall, H. pylori infection was significantly higher in the study group compared with the normal control group (OR = 2.87; 95% CI = 1.71-4.84; I(2) = 67.1; p < .0001, random effects analysis). The ORs for laryngeal carcinoma were 3.28 (95% CI = 1.91-5.63; I(2) = 58; p < .0001, random effects model). The ORs for pharyngeal cancer were 1.35 (95% CI = 0.86-2.12; p = .188, random effects model). CONCLUSION: This study supported the proposition that infection with H. pylori was related to laryngeal carcinoma, specifically in the hospital-based control group and diagnosed by polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA). Nevertheless, no significant relationship was discovered between H. pylori infection and pharyngeal cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2291-E2296, 2016.

The presence of Helicobacter pylori in laryngeal squamous cell carcinoma.

A definitive relationship between Helicobacter pylori (HP) and upper respiratory tract disorders has not been established. In this case-control study, we investigated the relationship between HP and laryngeal carcinoma by real-time PCR method in Turkey. 74 subjects were enrolled from patients who were admitted to the Otolaryngology Department. Formalin-fixed-paraffin-embedded tissue samples with laryngeal cancer were used and all samples were evaluated by real-time PCR method. Our study population included 72 males and 2 females with a mean age range of 62.7 years. Helicobacter Pylori was detected in only one case. The positive case was also investigated with histopathologic evaluation and HP immunohistochemistry. However, we could not detect HP in this case with both methods. This study revealed that HP might not contribute to the pathogenesis of laryngeal carcinoma. A definitive relationship between HP and upper respiratory tract disorders has not been established.

[The electron microscopic study of tumour-like structures on the vocal cords].

We have undertaken the electron microscopic investigation into peculiarities of six tumour-like structures on the vocal cords. The study has demonstrated changes in the number and distribution patterns of intercellular junctions, keratin and tonofilament contents in epithelial cells, basal membrane structure, and composition of the basic substance in lamina propria. All the examined tumour-like structures contained bacteria an two of them had viral particles in vacuoles of fibroblasts. Moreover, the bacteria were found on the surface of epithelium, between epithelial cells and in the basic substance in lamina propria. Cytoplasm of epithelial cells and fibroblasts not infrequently contained bacteria in the phase of division.

Prognostic significance and association of Helicobacter pylori infection in pharyngolaryngeal cancer.

The aim of this study is to assess the correlation between the Helicobacter pylori (H. pylori) serologic status of patients who underwent for curative resection for squamous cell carcinoma of the larynx and hypopharynx and their prognosis. From April 2004 to March 2005, we included eighty patients with laryngeal and hypopharyngeal cancer. Control group consisted of 20 healthy patients and 10 patients with Reinke's edema. Serologic status was assessed using an enzyme-linked immunosorbent assay kit for immunoglobulin G. Patients were followed for 5 years. H. pylori-positive serologic status was statistically significant for the case subjects (70.6 v/s 29.4 %; p < 0.001). Mean overall and disease-free survival were 50.7 months (range 46.9-54.5) and 52.1 months (range 48.3-55.7), respectively. H. pylori-positive serologic status was not associated with a poor prognosis in the Cox regression model (p = 0.77). We observed a positive association between H. pylori infection and laryngeal and hypopharyngeal cancer. But we fail to confirm that the presence of H. pylori infection is associated with poor outcome or a higher recurrence rate.

The role of H. pylori in the development of laryngeal squamous cell carcinoma.

AIM: This study aims to investigate the possible role of H. pylori as a cause of laryngeal squamous cell carcinoma. METHOD: This controlled study was performed with 31 consecutive laryngeal cancer and 28 cancer-free patients who underwent direct laryngoscopy and biopsy of laryngeal lesions. To document the previous H. pylori infection, serological analysis of the antibody titers was done. Immunohistochemical analyses were applied to the tissue samples. RESULTS: Serology was found positive at the 90.3% of the laryngeal cancer patients and 96.4% of the benign group. There were no statistically significant differences between the two groups (P > 0.05). Immunohistochemical analysis results were determined as negative at all of the specimens of laryngeal cancer patients and patients with benign lesions. CONCLUSION: There were no signs of colonization of H. pylori in laryngeal tissues of both groups' patients. It is thought that no relationship exists between the H. pylori infection and laryngeal squamous cell carcinoma.

[Laryngeal papillomatosis: problem update].

The objective of the present overview was to analyse the available data on etiology, pathogenesis, diagnostics, and treatment of laryngeal papillomatosis. It is shown that the pathogenetic mechanism underlying the development of this pathology is related to cell proliferation mechanisms. The human papilloma virus is most effectively identified by the polymerase chain reaction technique in combination with in situ hybridization. It is expected that new and more informative criteria for diagnostics, treatment,and prognosis of laryngeal papillomatosis will be proposed based on recent progress in molecular biology, morphology,and immunology. Different variants of the therapeutic strategy for the treatment of laryngeal papillomatosis are described.Modern practice of the management of laryngeal papillomatosis takes advantage of the three main approaches and/or their combination. First, further improvement of surgical techniques, such as the application of endoscopic devices and surgical lasers.Second, the search for new pharmaceutical agents (indole-3-carbinol, cidofovir, antiviral medicines, etc.) most frequently used for adjuvant therapy. Third, the development of new vaccination methods. Besides these three approaches, photodynamic therapy and the use of ionizing radiation are currently being studied as the tools for the treatment of extensive and recurrent laryngeal papillomatosis as well as the methods of laser-induced interstitial thermotherapy.

The Composition of Microbiome in Larynx and the Throat Biodiversity between Laryngeal Squamous Cell Carcinoma Patients and Control Population.

The throat is an ecological assemblage involved human cells and microbiota, and the colonizing bacteria are important factors in balancing this environment. However, this bacterial community profile has thus been poorly investigated. The purpose of this study was to investigate the microbial biology of the larynx and to analyze the throat biodiversity in laryngeal carcinoma patients compared to a control population in a case-control study. Barcoded pyrosequencing analysis of the 16S rRNA gene was used. We collected tissue samples from 29 patients with laryngeal carcinoma and 31 control patients with vocal cord polyps. The findings of high-quality sequence datasets revealed 218 genera from 13 phyla in the laryngeal mucosa. The predominant communities of phyla in the larynx were Firmicutes (54%), Fusobacteria (17%), Bacteroidetes (15%), Proteobacteria (11%), and Actinobacteria (3%). The leading genera were Streptococcus (36%), Fusobacterium (15%), Prevotella (12%), Neisseria (6%), and Gemella (4%). The throat bacterial compositions were highly different between laryngeal carcinoma subjects and control population (p = 0.006). The abundance of the 26 genera was significantly different between the laryngeal cancer and control groups by metastats analysis (p<0.05). Fifteen genera may be associated with laryngeal carcinoma by partial least squares discriminant analysis (p<0.001). In summary, this study revealed the microbiota profiles in laryngeal mucosa from tissue specimens. The compositions of bacteria community in throat were different between laryngeal cancer patients and controls, and probably were related with this carcinoma. The disruption of this bio-ecological niche might be a risk factor for laryngeal carcinoma.

Association between infection of virulence cagA gene Helicobacter pylori and laryngeal squamous cell carcinoma.

BACKGROUND: The aim of the study was to evaluate the presence of cagA gene Helicobacter pylori in etiopathogenesis of initiation and development of larynx squamous cell carcinoma (LSCC) and its predictable role as a prognostic factor. MATERIAL AND METHODS: The prospective, controlled study involved a series of 75 patients (65 male, 10 female, mean age 59.1 years, range 43 to 79 years) with larynx cancer. Samples of larynx cancerous tissue, each of 10-15 mg, were obtained from fresh tissues and were used for nucleic acid purification. DNA was extracted from 225 samples (larynx tumor - I (75), margin of tumor and normal tissue - II (75) and normal larynx tissue from opposite side to the tumor - III). All samples were subjected to H. pylori ureA detection by the PCR H. pylori diagnostic test. Samples that were positive for ureA H. pylori gene were evaluated for cagA H. pylori gene. RESULTS: Presence of H. pylori cagA gene was identified in 46,7% to 49,3% of 75 H. pylori ureA gene-positive larynx cancer depending of tissue location. There was a correlation of high incidence of positive cagA gene in larynx cancer tissue in supraglottic versus subglottic and glottic location. We observed a predominance of cagA gene in LSCC in patients with positive cervical lymph nodes and clinical stage T3 and T4. CONCLUSIONS: H. pylori is present in larynx tissue and may be a possible carcinogen or co-carcinogen in LSCC development, but that must be addressed by future investigations. The presence of cagA gene in larynx cancer tissues significantly decreases survival rate and increases the disease recurrence possibilities.

Helicobacter pylori infection in laryngeal diseases.

Clinical studies have shown that Helicobacter pylori can be found not only in the mucosa of the stomach, but in the pharyngeal and laryngeal regions as well. The aim of this prospective case-control study was to identify H. pylori infection in the biopsy material from the larynx of the patients suffering from benign laryngeal diseases (vocal fold polyps, laryngitis) and laryngeal cancer and to investigate the possible relationships between the laryngeal H. pylori and patients' socio-demographic data and laryngopharyngeal reflux. The results of the biopsy material from 67 adult patients treated for benign laryngeal diseases and laryngeal cancer and 11 individuals of the control group revealed that H. pylori infection could be identified in more than one-third of the patients. In the majority of cases H. pylori was found in the patients with chronic laryngitis (45.5%) and laryngeal cancer (46.2%). The findings of these sub-groups significantly differed from those of the control group (9.1%) (p < 0.05). No significant relationships between H. pylori infection found in the laryngeal region and patients' demographic data, their unhealthy habits and reflux-related symptoms or signs were obtained. It could be concluded that H. pylori can colonize in the larynx of patients with benign laryngeal diseases and laryngeal cancer. To clarify the role of H. pylori as a risk factor for laryngeal diseases further research is needed.