Comprehensive overexpression analysis of cyclic-di-GMP signalling proteins in the phytopathogen Pectobacterium atrosepticum reveals diverse effects on motility and virulence phenotypes

Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous bacterial signalling molecule produced by diguanylate cyclases of the GGDEF-domain family. Elevated c-di-GMP levels or increased GGDEF protein expression is frequently associated with the onset of sessility and biofilm formation in numerous bacterial species. Conversely, phosphodiesterase-dependent diminution of c-di-GMP levels by EAL- and HD-GYP-domain proteins is often accompanied by increased motility and virulence. In this study, we individually overexpressed 23 predicted GGDEF, EAL or HD-GYP-domain proteins encoded by the phytopathogen Pectobacterium atrosepticum strain SCRI1043. MS-based detection of c-di-GMP and 5'-phosphoguanylyl-(3'-5')-guanosine in these strains revealed that overexpression of most genes promoted modest 1-10-fold changes in cellular levels of c-di-GMP, with the exception of the GGDEF-domain proteins ECA0659 and ECA3374, which induced 1290- and 7660-fold increases, respectively. Overexpression of most EAL domain proteins increased motility, while overexpression of most GGDEF domain proteins reduced motility and increased poly-β-1,6-N-acetyl-glucosamine-dependent flocculation. In contrast to domain-based predictions, overexpression of the EAL protein ECA3549 or the HD-GYP protein ECA3548 increased c-di-GMP concentrations and reduced motility. Most overexpression constructs altered the levels of secreted cellulases, pectinases and proteases, confirming c-di-GMP regulation of virulence in Pe. atrosepticum. However, there was no apparent correlation between virulence-factor induction and the domain class expressed or cellular c-di-GMP levels, suggesting that regulation was in response to specific effectors within the network, rather than total c-di-GMP concentration. Finally, we demonstrated that the cellular localization patterns vary considerably for GGDEF/EAL/HD-GYP proteins, indicating it is a likely factor restricting specific interactions within the c-di-GMP network.

A novel staging model to classify oesophageal squamous cell carcinoma patients in China

BACKGROUND

Oesophageal squamous cell carcinoma (ESCC) is the predominant subtype of oesophageal carcinoma in China, with the overall 5-year survival rate of <10%. The current tumour-node-metastasis (TNM) staging system has become so complex that it is not easy to use in the life expectancy assessment. We aim to combine clinical variables and biomarkers to develop and validate a relative simple and reliable model, named the FENSAM, for ESCC prognosis.

METHODS

To build the FENSAM, we analysed 22 potential prognostic factors from 461 patients, including 9 biomarkers (Ezrin, Fascin, desmocollin 2 (DSC2), pFascin, activating transcription factor 3 (ATF3), connective-tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin (NGAL), NGAL receptor (NGALR), and cysteine-rich angiogenic protein 61 (CYR61)) and other 13 clinical variables. We selected significant factors associated with survival of ESCC patients, and used them to build our FENSAM model. We then obtained the hazard risk score of the model to classify ESCC patients. In addition, we validated the model in an independent cohort of 290 patients from the same hospital. The predictive performance of the model was assessed by the Area under the Receiver Operating Characteristic Curve (AUC) and Kaplan-Meier survival analysis.

RESULTS

We found six markers significantly associated with survival of ESCC patients (Ezrin, Fascin, ATF3, surgery extent, N-stage, and M-stage). They were combined to create a novel four-stage FENSAM model for patients' classification. FENSAM possessed a high classification precision similar to the TNM staging system, but with a much simpler model. The efficiency of FENSAM was evaluated by different quantiles of AUC and the results of survival analysis. The validation result demonstrated the potential of the FENSAM model to improve classification accuracy for ESCC patients.

CONCLUSIONS

FENSAM provides an alternative classifier for ESCC patients with a high classification precision using a simple model.

Effect of vitamin D therapy in addition to amitriptyline on migraine attacks in pediatric patients

The purpose of this study was to investigate the effect of supplementary vitamin D therapy in addition to amitriptyline on the frequency of migraine attacks in pediatric migraine patients. Fifty-three children 8-16 years of age and diagnosed with migraine following the International Headache Society 2005 definition, which includes childhood criteria, were enrolled. Patients were classified into four groups on the basis of their 25-hydroxyvitamin D [25(OH)D] levels. Group 1 had normal 25(OH)D levels and received amitriptyline therapy alone; group 2 had normal 25(OH)D levels and received vitamin D supplementation (400 IU/day) plus amitriptyline; group 3 had mildly deficient 25(OH)D levels and received amitriptyline plus vitamin D (800 IU/day); and group 4 had severely deficient 25(OH)D levels and was given amitriptyline plus vitamin D (5000 IU/day). All groups were monitored for 6 months, and the number of migraine attacks before and during treatment was determined. Calcium, phosphorus alkaline phosphatase, parathormone, and 25(OH)D levels were also determined before and during treatment. Results were compared between the groups. Data obtained from the groups were analyzed using one-way analysis of variance. The number of pretreatment attacks in groups 1 to 4 was 7±0.12, 6.8±0.2, 7.3±0.4, and 7.2±0.3 for 6 months, respectively (all P>0.05). The number of attacks during treatment was 3±0.25, 1.76±0.37 (P<0.05), 2.14±0.29 (P<0.05), and 1.15±0.15 (P<0.05), respectively. No statistically significant differences in calcium, phosphorus, alkaline phosphatase, or parathormone levels were observed (P>0.05). Vitamin D given in addition to anti-migraine treatment reduced the number of migraine attacks.

Effect of intra-abdominal volume increment on lungs in hemorrhagic shock

PURPOSE

Intra-abdominal hypertension (IAH) causes lung dysfunction in patients after hemorrhagic shock resuscitation. We performed intra-abdominal volume increment (IAVI) to IAH and studied its effect on pulmonary function.

METHODS

Eight minipigs established for IAH model by exsanquination until shock, incomplete blockage of portal vein and overload resuscitation were randomly divided into IAVI group (n=4) and sham-operated control group (n=4). Bladder pressure, arterial blood gas analysis and thoraco-abdominal computed tomography (CT) scans were measured. The minipigs were sacrificed 26 h after surgery, and lung samples were harvested for measuring the wet-to-dry weight ratio and hematoxylin-eosin staining.

RESULTS

Compared with sham-operated control group, the respiratory rate and paCO2 remarkably decreased and paO2 notably increased at 8 and 12 h in the IAVI group. The bladder pressure also notably decreased at 8, 12, and 22 h after IAVI treatment. However, a significant improvement in diaphragm height was observed at 22 h after IAVI treatment. The wet-to-dry weight ratio of the lungs in IAVI group was also significantly higher than that that in the sham-operated control group.

CONCLUSION

Our data indicate that IAVI surgery could improve the damaged pulmonary function caused by IAH after hemorrhagic shock resuscitation (Tab. 1, Fig. 7, Ref. 21).

[The distribution of 24 elements in urine from Shenzhen residents]

OBJECTIVE

This study aims to describe the distribution of 24 elements in urine of Shenzhen residents.

METHODS

According to the principle of equal probability of selection method, in March 2011 to July, total 11 communities were chosen as the basic sampling unit in Shenzhen, with 1 to 2 communities in each of the municipal district. Then 75 families from each sampling unit were selected using systematic sampling method. In total, 2 200 subjects were chosen. 10-20 ml morning middle stream urine was collected, and then detected the concentration of Li, Be, Sr, Cd, Cs, Ta, Pb, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Sn, Sb, Te, As, Se, Ru, Na, Mg, K, and analysed the discrepancies between gender and among age groups.

RESULTS

In those 24 elements, the concentration of Na was highest, the medians( 5th percentile (P 5), 95th percentile (P 95)) were 2 845.78 (920.29, 5 974.53) mg/L; Be was lowest, the result was 0.10(0.01, 0.58) µg/L. Except macroelements of Na (2 921.97 (985.14, 6 201.51) mg/L), Mg (48.20(8.23, 132.41) mg/L), K (2 323.20(683.98, 5 657.47) mg/L), the content of Rb was highest, 3.31(9.82, 7.83) mg/L, followed by Zn, 454.54(113.90, 1 320.00) µg/L, the content of V, Cr, Mn, Se, Tl was pretty low, the median of those elements all less than 1.00 µg/L. Statistically significant differences were found between genders and among age groups in Pb, Fe, Se (gender: Z values were 4.51, 2.53, 4.00, all P values were <0.05; age groups: H values were 55.67, 129.42, 18.46, all P values were <0.05). The medians(P5, P95) were 2.04 (0.57, 5.31), 202.88 (48.66, 564.90), 49.68 (14.34, 150.91) µg/L. The values of male were 2.22 (0.71, 5.33), 212 (47.50, 567.29), 53.42 (16.20, 160.63) µg/L. And the results of female were 1.95 (0.51, 5.24), 193.69 (49.52, 562.31), 46.62 (12.65, 142.80) µg/L; the values of less than 17 years old subjects were 1.66 (0.38, 3.77), 106.13 (26.69, 459.81), 51.86 (15.86, 169.71) µg/L; the results were 1.96 (0.52, 5.08), 209.83(52.87, 577.81), 54.14 (15.14, 144.11) µg/L in the group of 18 to 40 years old; in the 41 to 65 years old group, the values were 2.29 (0.78, 5.85), 228.15 (67.74, 615.16), 46.62 (13.95, 143.57) µg/L, the results were 2.19 (0.65, 5.69), 195.92(55.17, 490.24), 43.16 (12.42, 155.36) µg/L in 66 years old and more group.

CONCLUSION

Among these 24 elements in urine of Shenzhen residents, the Na concentration was highest, while Be was lowest. Elements (Pb, Fe, Se) differed with the condition of gender and age groups. So we should take all these factors into account to establish their reference values.

Chronic treatment with the mood-stabilizing drug lithium up-regulates nuclear factor E2-related factor 2 in rat pheochromocytoma PC12 cells in vitro

The mood-stabilizing drug lithium is the most commonly used treatment for bipolar disorder. Previous studies have shown that chronic treatment with lithium produces a protective effect against oxidative stress. Nuclear factor E2-related factor 2 (Nrf2) is a gene transcription factor that binds to the electrophile response element (EpRE) and triggers expression of various genes with antioxidant properties. Nrf2 contributes significantly to cytoprotection against oxidative stress. The purpose of this study is to determine the role of Nrf2 in the protective effect of lithium against oxidative stress. We found, using immunoblotting analysis, that chronic, but not acute treatment with lithium increased nuclear levels of Nrf2 in rat pheochromocytoma PC12 cells. DNA pull-down assay has shown that Nrf2 can bind to a double-strained oligonucleotide containing an EpRE site from glutathione s-transferase A4. Electrophorectic gel shift analysis further showed that chronic treatment with lithium increased Nrf-2-EpRE binding activity. We also found that knocking down Nrf2 with its short hairpin RNA inhibited lithium-increased expression of Nrf2 and suppressed the protective effect of lithium against hydrogen peroxide (H₂O₂)-reduced cell viability and H₂O₂-increased DNA fragmentation. Because Nrf2 can induce expression of various genes that play important roles in cytoprotection, the current findings suggest that Nrf2 may mediate the neuroprotective effect of lithium against oxidative stress.

Glucocorticoids increase protein carbonylation and mitochondrial dysfunction

Many major psychiatric illnesses have been associated with excessive and prolonged release of glucocorticoid stress hormones potentially leading to deleterious neuronal effects. Recent studies have suggested that oxidative stress is associated with psychiatric illnesses. Oxidative stress is an overproduction of reactive oxygen species (ROS) that overwhelms the cellular antioxidant capacity. The mitochondria are responsible for most oxygen consumption and are a major source of ROS production. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase also contributes significantly to ROS production. This study aims to elucidate the effects of glucocorticoids on oxidative damage to protein, mitochondrial function, NADPH oxidase activity, and antioxidant capacity. Rat pheochromocytoma PC12 cells were treated with corticosterone at concentrations of 0.031, 0.063, and 0.125 mmol/l for 24 h. Protein carbonylation, activities of mitochondrial complex I and III, activity of NADPH oxidase, total antioxidant capacity, and activities of superoxide dismutase (SOD) and catalase (CAT) were analyzed. We found that chronic treatment with corticosterone increased the amount of protein carbonylation in PC12 cells. Complex I activity was decreased with corticosterone treatment, while no change was seen in complex III activity or NADPH oxidase activity. Total antioxidant capacity was increased at the lowest dosage level tested. Although corticosterone treatment had no effect on CAT activity, corticosterone at the highest dosage significantly decreased SOD activity. These results suggest that excessive glucocorticoid activity can increase oxidative damage to protein, possibly by inhibiting activities of mitochondrial complex I and antioxidant enzyme SOD.

Dose Response and Pharmacokinetics of Tofacitinib (CP-690,550), an Oral Janus Kinase Inhibitor, in the Treatment of Chronic Plaque Psoriasis

Longitudinal nonlinear mixed effects modeling was used to characterize the dose–response profile of tofacitinib using data from a placebo-controlled dose-ranging study, where tofacitinib 2, 5, and 15 mg twice daily (b.i.d.) were evaluated for plaque psoriasis treatment. Bayesian estimation was applied with prior information derived from the literature: nonclinical and clinical data in psoriasis, as well as other indications. The probability to achieve a certain target effect associated with a given dose was calculated from the posterior samples. On the basis of these probabilities along with safety considerations, tofacitinib 5 and 10 mg b.i.d. were selected for further testing in confirmatory phase III clinical trials. Pharmacokinetics in patients with psoriasis was characterized using a population-based modeling approach, and body weight was identified as an important covariate. A subgroup analysis suggested reduced efficacy of tofacitinib with increasing body weight; however, it is unclear whether this trend could be explained by systemic exposure alone.

Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces

An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch.

An investigation of the effect of thiamine pyrophosphate on cisplatin-induced oxidative stress and DNA damage in rat brain tissue compared with thiamine

This study investigated the effects of thiamine pyrophosphate (TPP) at dosages of 10 and 20 mg/kg on oxidative stress induced in rat brain tissue with cisplatin and compared this with thiamine. Cisplatin neurotoxicity represents one of the main restrictions on the drug being given in effective doses. Oxidative stress is considered responsible for cisplatin toxicity. Our results showed that cisplatin increased the levels of oxidant parameters such as lipid peroxidation (thio barbituric acid reactive substance (TBARS)) and myeloperoxidase (MPO) in brain tissue and suppressed the effects of antioxidants such as total glutathione (GSH) and superoxide dismutase (SOD). TPP, especially at a dosage of 20 mg/kg, significantly reduced TBARS and MPO levels that increase with cisplatin administration compared with the thiamine group, while TPP significantly increases GSH and SOD levels. In addition, the level of 8-Gua (guanine), a product of DNA damage, was 1.7 ± 0.12 8-hydroxyl guanine (8-OH Gua)/105 Gua in brain tissue in the control group receiving cisplatin, compared with 0.97 ± 0.03 8-OH Gua/105 Gua in the thiamine pyrophosphate (20 mg/kg) group and 1.55 ± 0.11 8-OH Gua/105 Gua in the thiamine (20 mg/kg) group. These results show that thiamine pyrophosphate significantly prevents oxidative damage induced by cisplatin in brain tissue, while the protective effect of thiamine is insignificant.

Cancer risk with alemtuzumab following kidney transplantation

Alemtuzumab has been employed for induction therapy in kidney transplantation with low rates of acute rejection and excellent graft and patient survival. Antibody induction therapy has been linked to increased vulnerability to cancer. Data regarding malignancy rates with alemtuzumab are limited. We studied 1350 kidney transplant recipients (between 2001 and 2009) at the University of Pittsburgh Starzl Transplant Institute, for post-transplant de novo and recurrent malignancy, excluding non-melanoma skin cancer, among patients receiving alemtuzumab, thymoglobulin, and no induction therapies. Of the 1350 patients, 1002 (74.2%) received alemtuzumab, 205 (15.2%) received thymoglobulin, and 122 (9%) received no induction therapy. After excluding cancers occurring within 60 d post-transplantation, 43 (3.25%) malignancies were observed during a median follow-up time of 4.0 yr. The incidence of malignancy was 5.4% (1.09 per 100 patient-years [PY]) with thymoglobulin, 2.8% (0.74 per 100 PY) with alemtuzumab, and 3.3% (0.66 per 100 PY) with no induction (across all groups; p = 0.2342, thymoglobulin vs. alemtuzumab; p = 0.008). Thus, with the exception of non-melanoma skin cancer which we did not evaluate, alemtuzumab induction was not associated with increased cancer incidence post-kidney transplantation when compared to no induction therapy and was associated with lower cancer incidence when compared to thymoglobulin.

Radiological and clinical features of adult non-puerperal mastitis

OBJECTIVE

To describe the radiological and clinical features of adult non-puerperal mastitis and to determine the most accurate method of preventing unnecessary surgical procedures.

METHODS

Clinical and imaging findings were retrospectively reviewed in 51 females with non-puerperal mastitis, which was confirmed by biopsy/surgical pathology. All 51 patients had pre-operative MRI; 45 patients also had sonograms and 25 also had mammograms, pre-operatively.

RESULTS

Of the 51 cases with non-puerperal mastitis, 94.1% (48/51) were confirmed as having acute or chronic inflammation, and the other 3 had plasma cell mastitis; areola papillaris inflammation was found in 39.2% (20/51) of the cases. Overall, 6 of the 25 cases that were examined with mammography and 2 of the 45 cases that were examined with sonography appeared normal, but all 51 lesions were positively identified on MRI. Asymmetrical density (12/25) on mammograms and solitary or separated/contiguous, clustered, hypoechoic mass-like lesions (31/45) on ultrasound were the most common signs of non-puerperal mastitis. On enhanced MRI, 90.2% (46/51) of patients showed non-mass-like enhanced lesions. Multiple regional enhancements in the pattern of distribution (32/46) and separated or contiguous, clustered, rim-like enhancements in the pattern of internal enhancement (29/46) were the most common manifestations in non-mass-like enhanced lesions. Of the 51 patients, mastitis Type 1 and Type 2 in the time-signal intensity curve were detected in 47.1% and 51.0% of the patients, respectively. The breast imaging reporting and data system categories with the highest number of patients were Category 0 (9/25) on mammography, Category 4a on sonography (18/45) and Category 4a on MRI (29/51).

CONCLUSION

The findings from mammography and ultrasound are non-specific; therefore, using MR can be helpful in the diagnosis, especially in the presence of non-mass-like enhancements that are multiple, regional, separated, or contiguous, clustered and rim-like.

ADVANCES IN KNOWLEDGE

Mastitis is often neglected because of the lack of typical clinical signs and symptoms. This study has assessed and described the clinical features and imaging findings of adult non-puerperal mastitis on mammograms, sonograms and MRI and found that MRI is more specific in the diagnosis of disease.

Efficacy and safety of tofacitinib, an oral Janus kinase inhibitor, in the treatment of psoriasis: a Phase 2b randomized placebo-controlled dose-ranging study

BACKGROUND

Tofacitinib is a novel, oral Janus kinase inhibitor under investigation as a potential treatment for plaque psoriasis.

OBJECTIVES

This Phase 2b, 12-week, dose-ranging study (A3921047, NCT00678210) aimed to characterize the exposure-response, efficacy and safety of tofacitinib vs. placebo in patients with moderate-to-severe chronic plaque psoriasis.

METHODS

One hundred and ninety-seven patients were randomized. The primary endpoint was the proportion of patients achieving a ≥ 75% reduction in the Psoriasis Area and Severity Index (PASI 75) score at week 12.

RESULTS

At week 12, PASI 75 response rates were significantly higher for all tofacitinib twice-daily groups: 25·0% (2 mg; P < 0·001), 40·8% (5 mg; P < 0·0001) and 66·7% (15 mg; P < 0·0001), compared with placebo (2·0%). Significant increases in the proportion of PASI 75 responses were seen by week 4 and were maintained at week 12. Exposure-response over the 0-15 mg tofacitinib twice-daily dose range was successfully characterized. PASI 50, PASI 90 and Physician's Global Assessment response rates were also higher for tofacitinib vs. placebo. The most frequently reported adverse events (AEs) were infections and infestations: 22·4% (2 mg twice daily), 20·4% (5 mg twice daily), 36·7% (15 mg twice daily) and 32·0% (placebo). Discontinuations due to AEs were 6·0%, 2·0%, 4·1% and 6·1% of patients in the placebo, and 2, 5 and 15 mg twice-daily tofacitinib groups, respectively. Dose-dependent increases from baseline in mean serum high-density lipoprotein, low-density lipoprotein and total cholesterol, and decreases in haemoglobin and neutrophils were observed.

CONCLUSION

Short-term treatment with oral tofacitinib results in significant clinical improvement in patients with moderate-to-severe plaque psoriasis and is generally well tolerated.

Comparative effectiveness of pegfilgrastim, filgrastim, and sargramostim prophylaxis for neutropenia-related hospitalization: two US retrospective claims analyses

OBJECTIVE

Few studies have compared the effectiveness of filgrastim (FIL), pegfilgrastim (PEG), and sargramostim (SAR) to reduce the risk of febrile neutropenia (FN) associated with myelosuppressive chemotherapy (M-CT). Two large commercial database analyses were separately conducted to examine the incidence of neutropenia-related and all-cause hospitalizations associated with FIL, PEG, and SAR prophylaxis for patients receiving M-CT for non-Hodgkin lymphoma (NHL), Hodgkin lymphoma, or solid tumors.

METHODS

Separate retrospective US claims database analyses utilized patient data from January 1, 2004 to April 30, 2010 using the HealthCore Integrated Research Database (HIRD(SM)) and January 1, 2001 to August 31, 2009 using OptumInsight's (formerly Ingenix) database. Patients were ≥18 years old and treated with M-CT for NHL, Hodgkin lymphoma, and solid tumors. All identified M-CT cycles with prophylactic (first 5 days of cycle) FIL, PEG, or SAR were included in the analysis. Patterns of administration and incidence rates of all-cause and neutropenia-related hospitalization were examined on a per-cycle basis.

RESULTS

In total, 9330 and 8762 patients with cancer, representing 30,264 and 24,215 chemotherapy cycles (28,189 and 22,649 (PEG), 1669 and 1351 (FIL), 406 and 215 (SAR)) from the HIRD(SM) and OptumInsight databases, respectively, were included in the separate database analyses. Both the HIRD(SM) and OptumInsight analysis showed that SAR and FIL prophylaxis had a higher risk of neutropenia-related hospitalization (SAR: OR = 3.48 [95%CI = 2.11, 5.74] and 2.81 [1.62, 4.87]; FIL: 1.78 [1.28, 2.48] and 2.36 [1.82, 3.06], respectively) and all-cause hospitalization (SAR: 2.18 [1.41, 3.36] and 2.41 [1.58, 3.68]; FIL:1.57 [1.25, 1.97] and 1.95 [1.60, 2.38], respectively) vs PEG.

LIMITATIONS

Medical claims do not contain information about chemotherapy dose, and hospitalizations were not validated against the patient's chart.

CONCLUSION

In this comparative effectiveness study, use of PEG was associated with a lower risk of neutropenia-related and all-cause hospitalizations compared to use of FIL or SAR prophylaxis.

Technological properties and probiotic potential of Enterococcus faecium strains isolated from cow milk

AIM

To identify enterococci from the fermentation of milk for the production of nono, an African fermented dairy product, to determine the technological properties for suitability as starter cultures and safety as probiotics.

METHODS AND RESULTS

Enterococcus faecium CM4 and Enterococcus faecium 2CM1 were isolated from raw cow's milk. The strains were phenotypically and genotypically identified. Technological properties, safety investigations, in vitro adherence properties and antimicrobial characteristics were carried out. Strong acidification and tolerance to bile salts were recorded. The strains were bile salts hydrolytic positive and no haemolysis. There was no resistance to clinically relevant antibiotics. The strains exhibited adherence to human collagen type IV, human fibrinogen and fibronectin. The bacteriocins were active against Bacillus cereus DSM 2301, Bacillus subtilis ATCC 6633, Micrococcus luteus and Listeria monocytogenes. Bacteriocins were stable at pH 4-9 and on treatment with lipase, catalase, α-amylase and pepsin, while their activity was lost on treatment with other proteases. The bacteriocins produced were heat stable at 100°C for 10 min. The bacteriocin produced by the strains was identified as enterocin A.

CONCLUSIONS

The E. faecium strains in this study exhibited probiotic activity, and the safety investigations indicate their suitability as good candidates for a starter culture fermentation process.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of bacteriocin-producing E. faecium strains as starter cultures in fermented foods is beneficial but, however, their safety investigations as probiotics must be greatly emphasized.

[Rapid determination of 19 elements in human urine by inductively coupled plasma-mass spectrometry with dynamic reaction cell]

OBJECTIVE

A simple method is proposed for determination of Be, Rb, Sr, Cd, Pb, Cs, Tl, V, Cr, Mn, Ni, Co, Cu,Zn, Sn, Sb, Te, As and Se in urine by using inductively coupled plasma mass spectrometry with dynamic reaction cell.

METHODS

Prior to analysis, samples were diluted (1: 20) in a solution of nitric acid (3%, V/V). The DRC mode was applied to determine the content of V51, Cr52, Mn55, Ni58, Co59, Cu63, Zn64 Sn120, Sb121, Te130, As75 and Se80. For the other elements, the instrument was operated in standard mode.

RESULTS

The method detection limits were 2.7ng/L for Be9, 2.0ng/L for V51, 2.7ng/L for Cr52, 1.5ng/L for Mn55, 3.9ng/L for Ni58, 0.8ng/L for Co59, 5.8ng/L for Cu63, 35.3ng/L for Zn64, 32.4ng/L for As75, 21.1ng/L for Se80,1.4ng/L for Rb85, 4.2ng/ L for Sr88, 1.1 ng/L for Cd 9.1 ng/L for Sn120, 1.1ng/L for Sb121, 8.6ng/L for Te130, 0.1 ng/L for Cs133, 0.2ng/L for Tl205 and 1.0 ng/L for Pb208. The precisions of the method were in the range of 0.3% - 2.6%.

CONCLUSION

The proposed method was rapid, accurate and can be used for measurement with simple pre-treatment, less sample and lower cost. The method was also suitable for massive samples in screening and monitoring.