Combined multiplex loop-mediated isothermal amplification with lateral flow assay to detect sea and seb genes of enterotoxic Staphylococcus aureus.

UNLABELLED: Staphylococcal enterotoxins (SEs) are the most common cause of food poisoning worldwide and can induce symptoms, such as diarrhoea, vomiting and abdominal cramping. Thus, the aim of this study is to develop a multiplex loop-mediated isothermal amplification combined with a lateral flow assay (m-LAMP/LFA) to simultaneously detect the sea and seb genes of Staphylococcus aureus. The amplicons of the sea gene were labelled with digoxigenin (Dig) and biotin while those of seb gene were labelled with fluorescein isothiocyanate (FITC) and biotin. These amplicons were detected using a multiplex LFA with NeutrAvidin-tagged gold nanoparticles as the detection reagent. After optimization, the detection limit of this assay was 10(2)  CFU ml(-1) Staph. aureus, which was one tenth that of a multiplex PCR. This assay did not exhibit any cross-reactivity in detecting other enterotoxic Staph. aureus strains or other food pathogens. After 6 h of enrichment, this developed assay detected 1 CFU ml(-1) of Staph. aureus in milk, apple juice, cheese and rice. The developed m-LAMP/LFA method does not require expensive equipment and can be completely implemented within an 8-h workday. Therefore, this method can provide an effective means of quickly screening staphylococcal enterotoxin A- and/or staphylococcal enterotoxin B-producing Staph. aureus in food samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Staphylococcus aureus is one of the major foodborne pathogens worldwide, and its staphylococcal enterotoxin A and B are strongly associated with food poisoning. This work developed a multiplex loop-mediated isothermal amplification combined with a lateral flow assay (m-LAMP/LFA) to simultaneously detect the sea and seb genes of Staph. aureus in food samples. The assay has good specificity and sensitivity with ease-of-use features, making it ideal for on-site detection.

Changes of snoring sound after relocation pharyngoplasty for obstructive sleep apnoea: the surgery reduces mean intensity in snoring which correlates well with apnoea-hypopnoea index.

OBJECTIVE: To investigate objective changes of snoring after surgery in patients with obstructive sleep apnoea (OSA) and correlate these with changes in the apnoea-hypopnoea index (AHI). DESIGN: Prospective case series. SETTING: A novel measurement, Snore Map, was used to analyse full-night snore sounds in terms of the maximal/mean intensity, peak/mean frequency, snoring index and energy type (Snore Map type, 0-4). Snore sound was classified into three bands according to frequency energy spectrum: B1 (40-300 Hz), B2 (301-850 Hz) and B3 (851-2000 Hz). PARTICIPANTS: Thirty-four male and two female OSA patients (mean age, 39 years; mean AHI, 53.1/h; mean body mass index, 26.8 kg/m(2) ) with favourable anatomic structure were consecutively enrolled. MAIN OUTCOME MEASURES: Parameters of polysomnographies and Snore Maps at baseline and six months after operation were compared. Statistical significance was set at P < 0.05. RESULTS: Thirty-two patients completed this study. The mean reduction in the total-snoring index was insignificant but there were significant decreases in total mean intensity, total peak frequency, total mean frequency and Snore Map type after surgery. There were also significant decreases in the mean intensity in all three bands, the snoring index in B2/B3 and the mean frequency in B1 postoperatively. Changes in the total mean intensity, total mean frequency, B2 mean intensity and B3 snoring index positively correlated with change in the AHI. CONCLUSIONS: Relocation pharyngoplasty significantly decreases both the snoring sound intensity and snoring frequency. These reductions are directly proportional to the improvement of OSA.

Efficient production of transgenic melon via Agrobacterium-mediated transformation.

Oriental melon (Cucumis melo L. var. makuwa) is an important fruit for human consumption. However, this plant species is one of the most recalcitrant to genetic transformation. The lack of an efficient in vitro system limits the development of a reproducible genetic transformation protocol for Oriental melon. In this study, an efficient transgenic production method for Agrobacterium-mediated transformation using cotyledon explants of Oriental melon was developed. Cotyledon explants were pre-cultivated for two days in the dark, and the optimal conditions for transformation of melon were determined to be a bacteria concentration of OD600 0.6, inoculation for 30 min, and two days of co-cultivation. Transgenic melon plants were produced from kanamycin-resistant shoots. A total of 11 independent transgenic plants were regenerated with a transformation efficiency of 0.8% of the inoculated explants. The transgenic plants were phenotypically normal and fully fertile, which might be a consequence of the co-cultivation time.

Multidimensional evaluation of vocal quality in children with cochlear implants: a cross-sectional, case-controlled study.

OBJECTIVES: This study aimed to compare the differences in vocal quality between Mandarin-speaking children with cochlear implants and normal-hearing peers and to understand which cochlear implant usage parameters may predict unfavourable voice outcomes. DESIGN: A cross-sectional, case-controlled study. SETTING: A tertiary medical centre. PARTICIPANTS: Thirty-five pre-lingually deaf children (age = 10.3 ± 1.6 years; 17 boys and 18 girls) who had used cochlear implants for >2 years and 35 age- and gender-matched controls with normal hearing. MAIN OUTCOME MEASURES: Through sustained phonation of /a/ and reading of the Hare and Tortoise passage, the subjects' voice quality was analysed with aerodynamics and acoustics. A six-point scale was used for auditory-perceptual evaluation. A Pediatric Voice-Related Quality of Life Survey was filled out by the caregivers. RESULTS: The implanted subjects had significantly lower mean airflow rate (P = 0.006), higher phonation threshold pressure (P < 0.001), higher fundamental frequency variations (P < 0.001) and peak-amplitude variations (P < 0.001), wider fundamental frequency range (P = 0.043), wider speaking intensity range (P = 0.015) and greater perceptual severity level of monotone (P < 0.001), resonance (P < 0.001), loudness (P < 0.001) and strain (P = 0.006) than their normal-hearing peers. Duration of postoperative rehabilitation was an independent predictor of unfavourable mean speaking fundamental frequency (odds ratio = 8.56, P = 0.008). CONCLUSION: Inadequate postoperative rehabilitation may hinder the normalisation of Mandarin-speaking implantees' voice quality. A multidimensional analysis may precisely evaluate the voice of paediatric implantees; however, the generalisability of these findings requires different forms of validation, including data from other languages and other institutions.

A rudimentary epiglottis associated with Pierre Robin sequence.

Epiglottis anomaly associated with Pierre Robin sequence (PRS) is a rare occurrence. To the knowledge of the authors, this is the first reported case of epiglottic anomaly associated with PRS. Doctors should remain aware of this atypical presentation in a PRS patient, and the presented case highlights the clinical challenges that must be met to ensure effective treatment of the defect in terms of compromised respiration, swallowing and feeding.

Simultaneous midline laser glossectomy with palatopharyngeal surgery for obstructive sleep apnoea syndrome.

We investigate the outcome of performing tongue base reduction surgery and palatopharyngeal surgery in a single stage to determine whether the same-stage midline laser glossectomy (MLG) with extended uvulopalatal flap (EUPF) for obstructive sleep apnoea syndrome (OSAS) is a safe and effective procedure. Six male patients with a history of severe OSAS were recruited into the retrospective study. They were the first patients to undergo the MLG with EUPF procedure. Patients were identified to have retropalatal and hypopharyngeal sites of obstruction on the basis of fiberoptic endoscopy with Muller's manoeuvre and three-dimensional computerised tomography. No significant adverse events occurred. The follow-up polysomnography (6-month follow-up) revealed that the mean respiratory disturbance index from 50.7 to 11.6, snoring index from 230.9 to 137.3 and the minimal oxygen saturation from 76.3 to 88.8. This study confirms that the same-stage MLG with EUPF for OSAS is a safe and effective procedure.

The role of glottal gap in predicting aspiration in patients with unilateral vocal paralysis.

Aspiration has been frequently noted among patients suffering from vocal-fold paralysis. The association between a defect of glottal closure and aspiration in patients with unilateral vocal paralysis appears to have been rarely reported. The current study reviews collected data consisting of videotaped flexible nasoendoscopy and stroboscopy for patients with a unilateral vocal-fold paralysis. Mean normalized glottal gap areas for patients suffering vocal paralysis with associated aspiration are significant greater than that for the non-aspiration group. Subsequent to the surgical correction of the glottal gap, all patients recovered well from their earlier aspiration. The investigation of objectively derived data revealed that poor airway protection due to incomplete closure of the vocal fold was the major cause of aspiration for patients suffering unilateral vocal-fold paralysis. Intracordal autologous fat injection can successfully improve the breath control and eliminate aspiration in patients with vocal-fold paralysis.

Efficacy of radiofrequency volumetric tissue reduction of the soft palate in the treatment of snoring.

Traditional surgery for snoring often leads to intolerable postoperative pain. A new surgical treatment, radiofrequency volumetric tissue reduction (RVTR) of the soft palate, was carried out and its effect and safety in the management of snoring were evaluated. Thirty-two patients received a single treatment of RVTR with a mean follow-up period of 4.5 months. All patients were assessed by a questionnaire using the Snore Outcomes Survey (SOS) and the Epworth Sleepiness Scale (ESS). Postoperative pain, speech and swallowing disturbances were also evaluated. The postoperative scores of SOS and ESS all significantly improved (p<0.05). Postoperative pain, speech and swallowing disturbances were all mild 1-3 days after treatment. With the success of treatment defined as a postoperative snoring index (SI) of <3 or a reduction of the SI by >5 points by the visual analogue scale, the success rate was 81.3% in patients with a respiratory disturbance index (RDI) of <20, and 50% in those with an RDI of >20. We conclude that RVTR of the soft palate is an effective treatment for snoring, resulting in only mild postoperative discomfort. A patient whose RDI was <20 had a higher success rate with a single RVTR treatment.

Bronchial entrapment of a chicken bone for 14 years.

Prolonged airway entrapment of a foreign body is a rare occurrence. We report a case of a chicken bone retained in the right main bronchus for 14 years and highlight the importance of a foreign body in the airway in the differential diagnosis of chronic and intractable cough.

Development and validation of growth model for Yersinia enterocolitica in cooked chicken meats packaged under various atmosphere packaging and stored at different temperatures.

Mathematical models that can predict the growth of Yersinia enterocolitica in chicken meats were evaluated in this study. The growth curves for Y. enterocolitica in chicken meats variously packaged (air, vacuum, and modified atmosphere packaging [MAP]) and stored at various temperatures (4, 10, 16, 22, 28, and 34 degrees C) were constructed. The Gompertz model was applied to fit each of the experimental curves for the conditions mentioned above. The variations in the parameters, including lag time (lambda) and specific growth rate (mu), at various temperatures were then described by the following models: the variations in lag time were described by the Adair and Smith models and the variations in the specific growth rate were described by the Ratkowsky and Zwietering models. The various models were then compared using graphical and mathematical analyses such as mean square error (MSE), regression coefficient (r2), bias factor, and accuracy factor. The results indicate that the mean r values in the Gompertz model for chicken meats packaged in air, vacuum, and MAP were 0.99, 0.99, and 0.95, respectively. The lag time modeled with the Adair and Smith functions exhibited a greater variance and demonstrated larger errors. The MSEs were 0.0015 and 0.0017 for Ratkowsky and Zwietering models, respectively. The r2 values in the Ratkowsky and Zwietering models were both 0.99. The bias factor was 1.017 for the Ratkowsky model and 1.096 for the Zwietering model. The accuracy factor of the Zwietering model was 1.174, which was lower than that in the Ratkowsky model (1.275), indicating that the former model was more accurate than the latter in predicting the specific growth rate of Y. enterocolitica in chicken meats.

Isolation and characterization of a novel phytase from Penicillium simplicissimum.

Eighty-three isolates from different soil samples exhibited the potential for producing active extracellular phytase. The most active fungal isolate with phytase activity was identified as Penicillium simplicissimum. In shaking culture with enrichment medium, the highest extracellular phytase activity of the producing strain was 3.8 U/mL. The crude enzyme filtrate was purified to homogeneity using ultrafiltration. IEC and gel filtration chromatography. The molar mass of the purified enzyme was estimated to be 65 kDa on SDS-PAGE. The saccharide identification with periodic acid-Schiff reagent (PAS) and activity recognition by 1-naphthyl phosphate was all positive. The isoelectric point of the enzyme, as deduced by isoelectric focusing, was pH 5.8, the optimum pH and temperature being pH 4.0 and 55 degrees C, respectively. The purified enzyme revealed broad substrate specificity and was strongly inhibited by Fe2+, Fe3+ and Zn2+; however, no inhibition was found by EDTA and PMSF. Phytase activity was inhibited when 2 mmol/L of dodecasodium phytate was added and the Km for it was determined to be 813 mmol/L.

Antimicrobial activity of sulfur dioxide to certain lactic acid bacteria isolated from wines.

This study was conducted to investigate the relationship between pH and the toxicity of sulfur dioxide against homo- and hetero-lactic acid bacteria isolated from American acidic wines. Malolactic fermentation was found to be growth-associated in homo- and hetero-lactic strains. The pH of CBB broth had an insignificant effect on the specific death rate of these strains; the concentration of molecular sulfur dioxide had a great effect on the specific death rate and malate degradation. Laboratory or freshly isolated strains were exposed to various concentrations of free sulfur dioxide at pH 3.8 and 3.4. At pH 3.4, sulfur dioxide was more effective against lactic acid bacteria than at pH 3.8 since more was present as molecular sulfur dioxide and causing an increase in the specific death rate. Pediococcus strain BB was more resistant to sulfur dioxide than those hetero-lactic fermentation strains such as Leuconostoc oenos PSU-1 and ML-34. The effect of sulfur dioxide concentration on the viability of L. oenes ML-34, PSU-1, and Pediococcus strain BB appeared to be biphasic. No or little L-malic acid was degraded when the homo- and hetero-fermentative strains were killed by sulfur dioxide.

Isolation of astaxanthin over-producing mutants of Phaffia rhodozyma and their fermentation kinetics.

Phaffia rodozyma CCRC-21346, CBS-6938, and CBS-5908 were treated with mutagenic agent NTG (N-methyl-N'-nitro-N-nitrosoguanidine) several times, then they were plated onto yeast-malt agar containing beta-ionone as a selective medium. Several isolates had increased astaxanthin content compared with the parental natural isolates. NCHU-FS301, one of the NTG treated strains, produced considerably more astaxanthin (1515.63 micrograms/g yeast) than the parent CBS-6938 (565.08 micrograms/g yeast). In studying the effects of carbon sources on the red pigment formation, it was found that glucose supported the highest total astaxanthin production (7809.3 micrograms/l). Yeast extract was the best nitrogen source in supporting the highest total astaxanthin formation (8637.5 micrograms/l). Beef extract, yeast extract, and potassium nitrate added in an equal ratio as a nitrogen source supported more pigment formation (8052.6 micrograms/l) than the rest of the mixture tested. Using kinetic parameters of specific growth rate (mu) and specific astaxanthin productivity (qp) to judge the association between growth behavior and product formation, the NCHU-FS301 showed more positive growth-associated fermentation type than the parent strain. These astaxanthin-overproducing mutants could be useful for the aquacultural industry in providing a natural source of astaxanthin.