Molecular epidemiology and clinical characteristics of Clostridioides difficile infection in patients with inflammatory bowel disease from a teaching hospital.

BACKGROUND: Clostridioides difficile infection (CDI) in patients with inflammatory bowel disease (IBD) is of increasing concern. This study aimed to investigate the molecular epidemiology and antimicrobial susceptibilities of toxigenic C. difficile isolated from IBD patients and to evaluate the risk factors for CDI in IBD population. METHODS: Loose or watery stools from IBD patients were tested for glutamate dehydrogenase, C. difficile toxins A&B and anaerobic culture. Toxigenic C. difficile isolates were characterized by multi-locus sequence typing, ribotyping and antimicrobial susceptibility testing. RESULTS: The prevalence of CDI in IBD patients was 13.6% (43/317). The dominant sequence types (STs) were ST35 (20.9%), ST2 (18.6%) and ST37 (16.3%). The most common ribotypes (RTs) were RT 017 (18.6%), RT 012 (14.0%), and RT 220 (14.0%), whereas RT 027 and RT 078 were not detected in this study. All the isolates were susceptible to vancomycin and metronidazole. The multidrug resistance rate of C. difficile RT 017 was higher (p < 0.01) than that of other RT strains. Recent hospitalization, use of corticosteroids and proton pump inhibitors were related to increased risk of CDI in IBD patients; of these, recent hospitalization and proton pump inhibitors use were independent risk factors. CONCLUSION: Patients with IBD have a relatively high incidence rate of CDI. C. difficile RT 017 is most frequently isolated from IBD patients in this region and warrants more attention to its high resistance rate. Clinicians should pay greater attention to CDI testing in IBD patients with diarrhea to ensure early diagnosis and initiation of effective treatment.

[Single-breath and rebreathing methods for measurement of pulmonary diffusing function: a comparative study].

OBJECTIVE: To compare the difference of pulmonary diffusing capacity measured by single-breath (SB) and re-breathing (RB) in normal subjects, patients with interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD). METHODS: We enrolled a cohort of subjects from the Guangzhou Institute of Respiratory Disease between September 2011 and February 2012: control group 29 (male 9, female 20, 42-74 y), ILD group 32 (male 15, female 17, 41-72 y), COPD group 32 (male 28, female 4, 40-75 y). All subjects underwent pulmonary diffusing capacity test using SB or RB method according to random figures order list. Diffusing capacity of carbon monoxide per predicted measured by SB method (SB-DLCO%pred) of the normal group was used as the standard to adjust the diffusing capacity of carbon monoxide per predicted measured by RB method (RB-DLCO%pred) and diffusing capacity of carbon monoxide per liter of VA per predicted measured by RB (RB-DLCO/VA%pred) in the 3 groups, respectively. Comparisons between 2 groups were performed by using the independent-sample t test, among more than 2 groups by using the One-Way ANOVA test, while the ROC curve was used to calculate the area under curve (AUC) and its 95%CI. RESULTS: In the control group, 15 subjects' RB-DLCO%pred was lower than 80%, and the mean value (78.8 ± 2.1)% was also lower than 80%. Using SB-DLCO%pred of the normal group as a standard to adjust the RB-DLCO%pred, the corrected value was 1.097, and then this value was used to adjust RB-DLCO/VA%pred in the 3 groups, respectively. Before correction DLCO%pred [the control group: (91.2 ± 1.9)% vs (78.8 ± 2.1)%; the ILD group: (45.8 ± 2.6)% vs (60.0 ± 1.9)%;the COPD group: (66.3 ± 2.9)% vs (56.6 ± 1.6)%]and DLCO/VA%pred [the control group: (99.8 ± 2.3)% vs (84.6 ± 4.5)%; the ILD group: (75.9 ± 3.0)% vs (88.5 ± 5.4)%; the COPD group: (80.2 ± 3.7)% vs (50.6 ± 2.5)% ] between the SB and RB were statistically different among the 3 groups. After correction, only the DLCO%pred [(45.8 ± 2.6)% vs (65.8 ± 2.1)%], DLCO/VA%pred [ (75.9 ± 3.0)% vs (102.2 ± 6.2)%] of the ILD group and the DLCO/VA%pred [(80.2 ± 3.7) vs (58.3 ± 2.8)%] of the COPD group had significant difference between the 2 methods (t = -6.00-4.68, all P < 0.01) . The test time of re-breathing in the COPD group (106 ± 5) s was significant longer than that of the ILD group (73 ± 4) s and the control group (79 ± 5) s (F = 11.99, P < 0.01), and the correlation between DLCO/VA%pred and the test time(r = -0.661, P < 0.01) was higher than the relationship between DLCO%pred and the test time (r = -0.391, P < 0.01). Furthermore, in the ILD group, the area of RB-DLCO%pred under ROC was 0.893, 95%CI being 0.817-0.970. In the COPD group, the area of RB-DLCO/VA%pred under ROC was 0.895, 95%CI being 0.811-0.979. CONCLUSIONS: There were differences between re-breathing and single-breath in measuring diffusing capacity. The present predicted value of the re-breathing method needed further study to confirm its applicability. Re-breathing method was more consistent with the respiratory physiology, and might be a better method to detect diseased states.

Bisabolane-type sesquiterpenoids and bacillibactin from the marine-derived fungus Aspergillus sydowii SCSIO 41041 and their enzyme inhibiting activity.

Twelve compounds, including eleven bisabolane-type sesquiterpenoids (1 - 11), and one bacillibactin (12) were identified from marine-derived fungus Aspergillus sydowii SCSIO 41041 isolated from Creseis acicula. The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Biologically, all compounds were evaluated for their acetyl cholin-esterase (AChE) enzyme, pancreatic lipase (PL) enzyme, neuraminidase (NA) and phosphodiesterase 4 (PDE4) inhibitory activities. Compound 12 displayed significant inhibitory activity against neuraminidase (NA) with an IC50 value of 24.0 µM, which was equivalent to the positive drug oseltamivir phosphate (IC50 value of 20.0 µM). And the NA inhibitory activity was confirmed by molecular docking analysis.

A Practical Assessment of the Disinfectant Efficacy of UV Light with and without Ozone Using a Novel Transfer Hatch in a Research Animal Facility.

Most in vivo animal research and breeding using mice and rats in China takes place in facilities under barrier conditions. Items being moved across the barrier are typically disinfected using UV radiation in a transfer hatch. However, the time periods necessary for this disinfection technique are inefficient, and disinfection is frequently incomplete, especially if concealed surfaces are present. The current study used a newly developed transfer hatch incorporating both UV and ozone disinfection to examine disinfection efficacy against 4 bacteria species (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii). Disinfection trials used UV and ozone, applied separately and in combination, for up to 30 min. Separate and combined treatments were also tested with a UV barrier. We found that if UV radiation has direct contact with surfaces, it is an efficient disinfection method. However, where surfaces are concealed by a UV barrier, UV radiation performs relatively poorly. The results of this study indicate that a combination of UV and ozone produces the most effective disinfection and is markedly quicker than current disinfection times for UV applied on its own. This novel transfer hatch design therefore allows more complete and efficient disinfection, improves workflow, and reduces barrier breaches by pathogens that may affect animal health and welfare and compromise research outcomes.

Effectiveness of treatment of bedding and feces of laboratory animal with ozone.

BACKGROUND: The incineration and burying of the soiled bedding of laboratory animals, as well as using detergents to treat their feces, is hazardous to the environment. This highlights the need for an alternative, environmentally friendly solution for the treatment of the waste of laboratory animal facilities. This study aims to evaluate the efficacy of ozone disinfection of the soiled bedding and feces of laboratory animals. METHODS: Two grams of soiled beddings were randomly sampled from the cages of mice and rats. These samples were mixed in a beaker with 40ml saline. Ozone was piped into the beaker at a concentration of 500mg/h. Samples were taken from the beaker at time 0min, 30min, 45min and 60min after ozone treatment for microbiological culturing in an incubator for 48h. Colony form unit of each plate (CFU/plate) at each time point were counted, the mean CFU/plate at each time point after ozone treatment were compared with that present at time zero. Feces of rabbits and dogs were treated and pathogens were counted the similar way as that of bedding of the mice and rats; samples being taken at 0min, 15min, 30min, 45min and 60min. RESULTS: Pathogens were observed in beddings of both mice and rats as well as in feces of rabbits and dogs. Ozone treatment for 30min killed more than 93% of pathogens in the bedding of the two rodent species and 60min of treatment killed over 99% of pathogens. Treatment of rabbit and dog feces for 30min killed over 96% pathogens present, and 60min's treatment killed nearly all the pathogens. Both Gram positive and Gram negative pathogens were sensitive to ozone treatment. CONCLUSION: Ozone treatment of bedding and feces is an effective and environment friendly way to deal with the waste of animal facilities, saving energy and potentially enabling their reuse as fertilizer.

Genetic polymorphisms of phase II metabolic enzymes and lung cancer susceptibility in a population of Central South China.

A case-control study was conducted for analyzing the genetic polymorphisms of phase II metabolic enzymes in 97 patients with lung cancer and 197 healthy subjects from Han ethnic group of Hunan Province located in Central South China. The results showed that the frequencies of glutathione S-transferase (GST) M1-null (GSTM1-) or GSTT1-null (GSTT1-) genotype alone, or combined form of both in lung cancer patients were significantly higher than those of the controls. Genotypes of combining GSTP1 mutant/GSTM1(-) or GSTP1 mutant/GSTT1(-) led to high risk of lung cancer. Individuals carrying any two or all three of GSTM1(-), GSTT1(-) and GSTP1 mutant genotypes have a distinctly increased risk of lung cancer when compared to those with GSTM1 present (GSTM1+: GSTM1+/+ or GSTM1+/-), GSTT1 present (GSTT1+: GSTT1+/+ or GSTT1+/-) and GSTP1 wild genotypes. Furthermore, individuals possessing combined genotypes of N-acetyltransferase 2 (NAT2) rapid acetylator, GSTP1 mutant and both GSTT1(-) and GSTM1(-) have a remarkably higher lung cancer risk than those carrying combined NAT2 slow acetylator genotype, GSTP1 wild genotype and both GSTT1(+) and GSTM1(+) genotypes. All these findings suggest that the genetic polymorphisms of phase II metabolic enzymes affect the susceptibility of lung cancer in the Han ethnic group of Central South China.

Evaluation of our self-designed nanometer silicon membrane sandwich cup system for diagnosing tuberculosis.

BACKGROUND AND AIMS: A nanometer silicon membrane sandwich cup system was self-designed. It could concentrate the bacilli via 0.45-µm microporous filter membrane and semi-automate the acid-fast bacilli (AFB) by a bacteria-staining machine. The aim of the study was to assess the clinical value of our self-designed system for diagnosing tuberculosis (TB). METHODS: A total of 1993 sputum specimens obtained from patients with confirmed or suspected TB were subjected to direct or concentrated specimens smear at XiangYa Hospital, Central South University between May 2012 and February 2013. In addition, all the specimens were also inoculated into Lowenstein-Jensen (L-J) media, and culture results were considered as the gold standard for calculating sensitivity and specificity. RESULTS: Compared with direct smear examination, an increased density of red stained bacilli was observed in the self-designed nanometer silicon membrane sandwich cup analysis under the microscope. The positive rate of the self-designed analysis was significantly higher than that of direct AFB smear [10.9% (217/1993) vs 6.2% (123/1993), P < 0.05]. The sensitivity of the self-designed system increased (97.3% vs 55.2%, P < 0.05) without a loss of specificity (100% vs 100%) for identifying positive TB cases compared with the direct smear method. CONCLUSION: The self-designed nanometer silicon membrane sandwich cup and semi-automatic bacteria-staining machine could more efficiently and rapidly detect the AFB in respiratory specimens than direct microscopy. This is a novel and safe examination, and it may replace direct smear examination for the diagnosis of patients with TB.

Leukotriene D4 inhalation challenge for predicting short-term efficacy of montelukast: a pilot study.

INTRODUCTION: The convenient measure to predict efficacy of leukotriene receptor antagonist is lacking. OBJECTIVES: To determine if leukotriene D4 inhalation challenge predicts short-term efficacy of montelukast in asthma. METHODS: In this open-labelled 28-day trial, 45 patients with asthma were allocated to leukotriene-sensitive and leukotriene-insensitive group to receive montelukast monotherapy (10 mg, once daily) based on the positive threshold of leukotriene D4 inhalation challenge test (4.800 nmol). Miscellaneous measurements comprised fractional exhaled nitric oxide, methacholine inhalation challenge, Asthma Control Test and Asthma Quality of Life Questionnaire. Peak expiratory flow was self-monitored throughout the treatment. End point assessments were performed 3 to 5 days after montelukast withdrawal. RESULTS: Twenty-three patients in leukotriene-sensitive group and 10 leukotriene-insensitive group completed the study. Both groups differed neither in 28-day peak expiratory flow rate nor in maximal weekly peak expiratory flow (both P > 0.05). However, minimal weekly peak expiratory flow was significantly higher in leukotriene-insensitive group throughout the treatment course (all P < 0.05) except for week 1 (P > 0.05). Both groups did not differ statistically in the post-treatment improvement in forced expiratory volume in 1 s (FEV1 ) predicted% prior to inhalation challenge, fractional exhaled nitric oxide or the airway responsiveness to leukotriene D4 or methacholine (all P > 0.05). There was a marked increase in Asthma Control Test score and the symptom score of Asthma Quality of Life Questionnaire in both groups (both P < 0.05). The overall significance of Logistic regression model was unremarkable (P = 0.467). CONCLUSION: Responsiveness to inhaled leukotriene D4 alone might not be sufficient to predict the short-term efficacy of montelukast monotherapy in patients with asthma.

Vibration response imaging in idiopathic pulmonary fibrosis: a pilot study.

BACKGROUND: Vibration response imaging (VRI) is a novel imaging technique and little is known about its characteristics and diagnostic value in idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the features of VRI in subjects with IPF. METHODS: We enrolled 23 subjects with IPF (42-74 y old) and 28 healthy subjects (42-72 y old). Subjects with IPF were diagnosed by lung biopsy and underwent VRI, spirometry, lung diffusion testing, and chest x-ray or computed tomography, which entailed assessment of the value of VRI indices. RESULTS: The total VRI score correlated statistically with single-breath carbon monoxide diffusing capacity percent predicted (r = -0.30, P = .04), but not with FVC percent predicted, FEV1 percent predicted, and FEV1/FVC (r = -0.27, -0.22, and 0.19; all P > .05). Compared with healthy subjects (17.9%), 20 subjects with IPF (86.96%, P < .01) presented with significantly increased crackles. The difference in quality lung data in all lung regions was unremarkable (all P > .05), except for the upper right and lower left lobes (P < .05). Overall, VRI parameters yielded acceptable assay sensitivity and specificity. Maximum energy frame was characterized by the highest diagnostic value (sensitivity, 1.00; specificity, 0.82), followed by presence of abundant crackles (sensitivity, 0.70; specificity, 0.96). Total VRI score was not a sensitive indicator of IPF, owing to low assay sensitivity (0.70) and specificity (0.64). CONCLUSIONS: VRI may be helpful to discriminate between IPF subjects and healthy individuals. Maximum energy frame and abundant crackles might serve as a diagnostic tool for IPF.

Prevalence and associated factors of corneal blindness in Ningxia in northwest China.

AIM: To describe the prevalence and demographic characteristics of corneal blindness in an urban and rural region of Ningxia, located in the northwest part of China. METHODS: A stratified, randomized sampling procedure was employed in the study, including urban and rural area of all age group. Visual acuity, anterior segment and ocular fundus were checked. Related factor of corneal disease, including age, gender, education status, ethnic group, location and occupation, were identified according to uniform customized protocol. An eye was defined to be corneal blindness if the visual acuity was <20/400 due to a corneal disease. RESULTS: Three thousand individuals (1290 from urban area and 1710 from rural area) participated in the investigation, with a response rate of 80.380%. The prevalence of corneal blindness was 0.023% in both eyes and 0.733% in at least one eye. The blindness in at least one eye with varied causes was present in 106 participants (3.533%) and in bilateral eyes in 34 participants (1.133%). The corneal diseases accounted for 20.754% of blindness in at least one eye and 20.588% of bilateral blindness. The prevalence of corneal disease was higher in older and Han ethnic group, especially those who occupied in agriculture and outdoor work. People with corneal blindness were more likely to be older and lower education. Rural population were more likely to suffer from bilateral corneal blindness than the urban population in ≥59-year group (χ (2)=6.716, P=0.019). Infectious, trauma and immune corneal disease were the three leading causes of corneal disease. Trauma corneal disease was more likely leading to blindness in one eye. However, infectious and immune corneal diseases make more contribution to the bilateral corneal blindness. CONCLUSION: Corneal blindness is a significant burden of in Ningxia population, encompassing a variety of corneal infections and trauma; the majority of those were avoidable. Health promotion strategies and good hygienic conditions have to be developed.

Impulse oscillometry for leukotriene D4 inhalation challenge in asthma.

BACKGROUND: The value of impulse oscillometry (IOS) for bronchial provocation testing is poorly defined. We investigated the positive threshold derived from the parameters and diagnostic power of IOS for asthma with the leukotriene D(4) bronchial provocation test. METHODS: We enrolled 62 subjects with asthma and 21 healthy subjects. IOS was employed to perform the leukotriene D(4) bronchial provocation test, followed by spirometry. The positive threshold was determined based on the cutoff point in the receiver operating characteristic curve, from which the parameters with the highest diagnostic power were obtained. RESULTS: Airway impedance at 5 Hz (Z(5)), resistance at 5 Hz (R(5)), and resonance frequency had the highest diagnostic power (areas under curve 0.82, 0.82, and 0.81, respectively), with increases of 57%, 43%, and 63%, corresponding to a 20% decrease in FEV(1), respectively. IOS indices yielded assay sensitivity and specificity similar to that of spirometry. The positive threshold for IOS, defined as either a 57% increase in Z(5) or a 63% increase in resonance frequency in the bronchial provocation test, yielded an assay accuracy of 0.6 in subjects with asthma. CONCLUSIONS: IOS during the leukotriene D(4) bronchial provocation test has a diagnostic power similar to that of spirometry. Either a 57% increase in Z(5) or a 63% increase in resonance frequency may be regarded as a surrogate of FEV(1) decrease to determine airway hyper-responsiveness in asthma.

Genetic polymorphisms of metabolic enzymes CYP1A1, CYP2D6, GSTM1 and GSTT1 and leukemia susceptibility.

The genetic polymorphisms of biotransformation phase I enzymes, cytochrome P450 (CYP1A1 and CYP2D6), and phase II enzymes, glutathione S-transferase (GSTM1 and GSTT1), were analyzed in 204 healthy persons and 348 leukemia patients, who suffered from also acute lymphoblastic leukemia (ALL), acute nonlymphoblastic leukemia (ANLL) chronic myelogenous leukemia (CML), from the Han ethnic group in Changsha City of Hunan Province of China. Our results showed that the frequencies of polymorphisms of CYP1A1, CYP2D6 and GSTT1 among the groups including acute lymphoblastic leukemia, ANLL, chronic myelogenous leukemia and healthy control have no significant differences. The variation of GSTM1-null genotype alone correlated with the development of ANLL. The combined genotypes of GSTM1-null with GSTT1-null, or GSTM1-null with CYP1A1 heterozygous mutant, or GSTM1-null with CYP1A1 heterozygous mutant and CYP2D6 heterozygous mutant, or GSTM1-null with CYP1A1 heterozygous mutant, CYP2D6 heterozygous mutant and GSTT1-null were found in individuals with high risk of ANLL. All these findings suggest that GSTM1-null genotype alone or in coordination with the relevant genotypes of other metabolic enzymes might be susceptibility factors in the etiology of ANLL.

[Study on the relationship between polymorphisms of Cyp1A1, GSTM1, GSTT1 genes and the susceptibility to acute leukemia in the general population of Hunan province].

OBJECTIVE: Based on the distribution of genetic polymorphisms regarding phase I metabolic enzyme cytochrome P450 1A1 (CYP1A1) and phase II metabolic enzymes glutathione S-transferase GSTM1 and GSTT1 genotypes in acute leukemia patients and health controls among general population of Hunan in China, this study was to explore the relationship between these gene polymorphisms and the susceptibility to acute leukemia. METHODS: Using case-control methodology, we studied 204 healthy controls and 232 patients with acute leukemia, of which 112 patients were suffering acute lymphoblastic leukemia (ALL) and 120 with acute non-lymphoblastic leukemia (ANLL). The frequencies of the genotypes were detected by PCR and PCR-RFLP techniques. RESULTS: The variation frequencies of CYP1A1 gene (Msp I polymorphisms, site 3801T-C variation) in ALL and ANLL groups were 74.1% and 70.8% respectively which were higher than 63.3% appeared in the healthy controls. However, the differences between patients (ALL or ANLL) and healthy controls were not statistically significant (P > 0.05 for both). The null genotype of GSTM1 (GSTM1 -/-) in ALL group was 60.7%, which was not significantly different from the controls (55.4%). However, GSTM1 -/- genotype in ANLL group was 68.3%, significantly different from the controls (P < 0.05). The null genotypes among GSTT1 (GSTT1 -/-) in ALL, ANLL and control group were 50.9%, 55.0% and 49.0% but their differences were not statistically significant (P > 0.05). The incidences of GSTM1 -/- and GSTT1 -/- combined genotype in ALL, ANLL and control group were 33.0%, 40.0% and 27.5%, of which the difference between ANLL group and control group was statistically significant (P < 0.05) and CYP1A1 gene heterozygous mutation type or homozygous mutation type combined with GSTM1 -/- and GSTT1 -/- increased the risk of ANLL (OR value 1.890, 95% CI: 1.084-3.295). CONCLUSION: These results indicated that both the variation of CYP1A1 gene or GSTT1 -/- genotype alone might not be associated with the susceptibility of acute leukemia while GSTM1 -/- genotype alone or combined with GSTT1 -/- or the 3801 T-C variation of CYP1A1 gene were correlated with ANLL. These findings suggest that GSTM1 - / - genotype alone or in combination with other defective genotypes might serve as risk factors to the etiology of ANLL.