Transient increase of ATP as a response to temperature up-shift in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Background  

Escherichia coli induces the heat shock response to a temperature up-shift which is connected to the synthesis of a characteristic set of proteins, including ATP dependent chaperones and proteases. Therefore the balance of the nucleotide pool is important for the adaptation and continuous function of the cell. Whereas it has been observed in eukaryotic cells, that the ATP level immediately decreased after the temperature shift, no data are available for E. coli about the adenosine nucleotide levels during the narrow time range of minutes after a temperature up-shift.     

Effects of temperature and medium composition on inhibitory activities of gossypol‐related compounds against aflatoxigenic fungi

Aims

To investigate the effects of temperature and medium composition on growth/aflatoxin inhibitory activities of terpenoids gossypol, gossypolone and apogossypolone against Aspergillus flavus and A. parasiticus.

Methods and Results

The compounds were tested at a concentration of 100 μg ml^?1 in a Czapek Dox (Czapek) agar medium at 25, 31 and 37°C. Increased incubation temperature marginally increased growth inhibition caused by these compounds, but reduced the aflatoxin inhibition effected by gossypol. Gossypolone and apogossypolone retained good aflatoxin inhibitory activity against A. flavus and A. parasiticus at higher incubation temperatures. However, increased temperature also significantly reduced aflatoxin production in control cultures. The effects of the terpenoids on fungal growth and aflatoxin production against the same fungi were also determined in Czapek, Czapek with a protein/amino acid addendum and yeast extract sucrose (YES) media. Growth of these fungi in the protein‐supplemented Czapek medium or in the YES medium greatly reduced the growth inhibition effects of the terpenoids. Apogossypolone displayed strong anti‐aflatoxigenic activity in the Czapek medium, but this activity was significantly reduced in the protein‐amended Czapek and YES media. Gossypol, which displayed little to no aflatoxin inhibitory activity in the Czapek medium, did yield significant anti‐aflatoxigenic activity in the YES medium.

Conclusions

Incubation temperature and media composition are important parameters involved in the regulation of aflatoxin production in A. flavus and A. parasiticus. These parameters also affect the potency of growth and aflatoxin inhibitory activities of these gossypol‐related compounds against aflatoxigenic fungi.

Significance and Impact of the Study

Studies utilizing gossypol‐related compounds as inhibitory agents of biological activities should be interpreted with caution due to compound interaction with multiple components of the test system, especially serum proteins.     

Enhanced inhibition of Aspergillus niger on sedge (Lepironia articulata) treated with heat‐cured lime oil

Aims

This study aimed to examine heat curing effect (30–100°C) on antifungal activities of lime oil and its components (limonene, p‐cymene, β‐pinene and α‐pinene) at concentrations ranging from 100 to 300 μl ml^?1 against Aspergillus niger in microbiological medium and to optimize heat curing of lime oil for efficient mould control on sedge (Lepironia articulata).

Methods and Results

Broth dilution method was employed to determine lime oil minimum inhibitory concentration, which was at 90 μl ml^?1 with heat curing at 70°C. Limonene, a main component of lime oil, was an agent responsible for temperature dependencies of lime oil activities observed. Response surface methodology was used to construct the mathematical model describing a time period of zero mould growth on sedge as functions of heat curing temperature and lime oil concentration. Heat curing of 90 μl ml^?1 lime oil at 70°C extended a period of zero mould growth on sedge to 18 weeks under moist conditions.

Conclusions

Heat curing at 70°C best enhanced antifungal activity of lime oil against A. niger both in medium and on sedge.

Significance and Impact of the Study

Heat curing of lime oil has potential to be used to enhance the antifungal safety of sedge products.     

Temperature limited fed-batch technique for control of proteolysis in <Emphasis Type="Italic">Pichia pastoris</Emphasis> bioreactor cultures

Background  

A temperature limited fed-batch (TLFB) technique is described and used for Pichia pastoris Mut⁺ strain cultures and compared with the traditional methanol limited fed-batch (MLFB) technique. A recombinant fusion protein composed of a cellulose-binding module (CBM) from Neocallimastix patriciarum cellulase 6A and lipase B from Candida antarctica (CALB), was produced and secreted by this strain.     

Identification and characterization of rhizosphere fungal strain MF‐91 antagonistic to rice blast and sheath blight pathogens

Aim

To examine the inhibition effects of rhizosphere fungal strain MF‐91 on the rice blast pathogen Magnaporthe grisea and sheath blight pathogen Rhizoctonia solani.

Methods and Results

Rhizosphere fungal strain MF‐91 and its metabolites suppressed the in vitro mycelial growth of R. solani. The inhibitory effect of the metabolites was affected by incubation temperature, lighting time, initial pH and incubation time of rhizosphere fungal strain MF‐91. The in vitro mycelial growth of M. grisea was insignificantly inhibited by rhizosphere fungal strain MF‐91 and its metabolites. The metabolites of rhizosphere fungal strain MF‐91 significantly inhibited the conidial germination and appressorium formation of M. grisea. Moreover, the metabolites reduced the disease index of rice sheath blight by 35·02% in a greenhouse and 57·81% in a field as well as reduced the disease index of rice blast by 66·07% in a field. Rhizosphere fungal strain MF‐91 was identified as Chaetomium aureum based on the morphological observation, the analysis of 18S ribosomal DNA internal transcribed spacer sequence and its physiological characteristics, such as the optimal medium, temperature and initial pH for mycelial growth and sporulation production.

Conclusions

Rhizosphere fungus C. aureum is effective in the biocontrolling of rice blast pathogen M. grisea and sheath blight pathogen R. solani both in in vitro and in vivo conditions.

Significance and Impact of the Study

This study is the first to show that rhizosphere fungus C. aureum is a potential fungicide against rice blast and sheath blight pathogens.     

Herd prevalence of Enterobacteriaceae producing CTX‐M‐type and CMY‐2 β‐lactamases among Japanese dairy farms

Aims

To determine the herd prevalence of Enterobacteriaceae producing CTX‐M‐type extended‐spectrum β‐lactamases (ESBLs) among 381 dairy farms in Japan.

Methods and Results

Between 2007 and 2009, we screened 897 faecal samples using BTB lactose agar plates containing cefotaxime (2 μg ml^?1). Positive isolates were tested using ESBL confirmatory tests, PCR and sequencing for CTX‐M, AmpC, TEM and SHV. The incidence of Enterobacteriaceae producing CTX‐M‐15 (n = 7), CTX‐M‐2 (n = 12), CTX‐M‐14 (n = 3), CMY‐2 (n = 2) or CTX‐M‐15/2/14 and CMY‐2 (n = 4) in bovine faeces was 28/897 (3·1%) faecal samples. These genes had spread to Escherichia coli (n = 23) and three genera of Enterobacteriaceae (n = 5). Herd prevalence was found to be 20/381 (5·2%) dairy farms. The 23 E. coli isolates showed clonal diversity, as assessed by multilocus sequence typing and pulsed‐field gel electrophoresis. The pandemic E. coli strain ST131 producing CTX‐M‐15 or CTX‐M‐27 was not detected.

Conclusions

Three clusters of CTX‐M (CTX‐M‐15, CTX‐M‐2, CTX‐M‐14) had spread among Japanese dairy farms.

Significance and Impact of the Study

This is the first report on the prevalence of multidrug‐resistant CTX‐M‐15–producing E. coli among Japanese dairy farms.     

Phenotypic and genetic diversity in <Emphasis Type="Italic">Sinorhizobium meliloti</Emphasis> and <Emphasis Type="Italic">S. medicae</Emphasis> from drought and salt affected regions of Morocco

Background  

Sinorhizobium meliloti and S. medicae are symbiotic nitrogen fixing bacteria in root nodules of forage legume alfalfa (Medicago sativa L.). In Morocco, alfalfa is usually grown in marginal soils of arid and semi-arid regions frequently affected by drought, extremes of temperature and soil pH, soil salinity and heavy metals, which affect biological nitrogen fixing ability of rhizobia and productivity of the host. This study examines phenotypic diversity for tolerance to the above stresses and genotypic diversity at Repetitive Extragenic Pallindromic DNA regions of Sinorhizobium nodulating alfalfa, sampled from marginal soils of arid and semi-arid regions of Morocco.     

Cell-associated hemolysis activity in the clinical strain of <Emphasis Type="Italic">Pseudomonas fluorescens MFN1032</Emphasis>

Background  

MFN1032 is a clinical Pseudomonas fluorescens strain able to grow at 37°C. MFN1032 cells induce necrosis and apoptosis in rat glial cells at this temperature. This strain displays secretion-mediated hemolytic activity involving phospholipase C and cyclolipopeptides. Under laboratory conditions, this activity is not expressed at 37°C. This activity is tightly regulated and is subject to phase variation.     

Crucial role of zebrafish <Emphasis Type="Italic">prox1</Emphasis>in hypothalamic catecholaminergic neurons development

Background  

Prox1, the vertebrate homolog of prospero in Drosophila melanogaster, is a divergent homeogene that regulates cell proliferation, fate determination and differentiation during vertebrate embryonic development.     

Genome-wide screen for temperature-regulated genes of the obligate intracellular bacterium, <Emphasis Type="Italic">Rickettsia typhi</Emphasis>

Background  

The ability of rickettsiae to survive in multiple eukaryotic host environments provides a good model for studying pathogen-host molecular interactions. Rickettsia typhi, the etiologic agent of murine typhus, is a strictly intracellular gram negative α-proteobacterium, which is transmitted to humans by its arthropod vector, the oriental rat flea, Xenopsylla cheopis. Thus, R. typhi must cycle between mammalian and flea hosts, two drastically different environments. We hypothesize that temperature plays a role in regulating host-specific gene expression, allowing R. typhi to survive in mammalian and arthropod hosts. In this study, we used Affymetrix microarrays to screen for temperature-induced genes upon a temperature shift from 37°C to 25°C, mimicking the two different host temperatures in vitro.     

Rates of evolution in stress-related genes are associated with habitat preference in two <Emphasis Type="Italic">Cardamine</Emphasis> lineages

Background  

Elucidating the selective and neutral forces underlying molecular evolution is fundamental to understanding the genetic basis of adaptation. Plants have evolved a suite of adaptive responses to cope with variable environmental conditions, but relatively little is known about which genes are involved in such responses. Here we studied molecular evolution on a genome-wide scale in two species of Cardamine with distinct habitat preferences: C. resedifolia, found at high altitudes, and C. impatiens, found at low altitudes. Our analyses focussed on genes that are involved in stress responses to two factors that differentiate the high- and low-altitude habitats, namely temperature and irradiation.     

Para‐psychobiotic Lactobacillus gasseri CP2305 ameliorates stress‐related symptoms and sleep quality

Aims

To confirm the stress‐relieving effects of heat‐inactivated, enteric‐colonizing Lactobacillus gasseri CP2305 (paraprobiotic CP2305) in medical students taking a cadaver dissection course.

Methods and Results

Healthy students (21 males and 11 females) took paraprobiotic CP2305 daily for 5 weeks during a cadaver dissection course. The General Health Questionnaire and the Pittsburgh Sleep Quality Index were employed to assess stress‐related somatic symptoms and sleep quality respectively. The aggravation of stress‐associated somatic symptoms was observed in female students (P = 0·029). Sleep quality was improved in the paraprobiotic CP2305 group (P = 0·038), particularly in men (P = 0·004). Among men, paraprobiotic CP2305 shortened sleep latency (P = 0·035) and increased sleep duration (P = 0·048). Diarrhoea‐like symptoms were also effectively controlled with CP2305 (P = 0·005) in men. Thus, we observed sex‐related differences in the effects of paraprobiotic CP2305. In addition, CP2305 affected the growth of faecal Bacteroides vulgatus and Dorea longicatena, which are involved in intestinal inflammation.

Conclusions

CP2305 is a potential paraprobiotic that regulates stress responses, and its beneficial effects may depend on specific cell component(s).

Significance and Impact of the Study

This study characterizes the effects of a stress‐relieving para‐psychobiotic in humans.     

Test method development to evaluate hot,humid air decontamination of materials contaminated with Bacillus anthracis ∆Sterne and B. thuringiensis Al Hakam spores

Aims

To develop test methods and evaluate the survival of Bacillus anthracis ?Sterne and Bacillus thuringiensis Al Hakam spores after exposure to hot, humid air.

Methods and Results

Spores (>7 logs) of both strains were dried on six different test materials. Response surface methodology was employed to identify the limits of spore survival at optimal test combinations of temperature (60, 68, 77°C), relative humidity (60, 75, 90%) and time (1, 4, 7 days). No spores survived the harshest test run (77°C, 90% r.h., 7 days), while > 6·5 logs of spores survived the mildest test run (60°C, 60% r.h., 1 day). Spores of both strains inoculated on nylon webbing and polypropylene had greater survival rates at 68°C, 75% r.h., 4 days than spores on other materials. Electron microscopy showed no obvious physical damage to spores using hot, humid air, which contrasted with pH‐adjusted bleach decontamination.

Conclusions

Test methods were developed to show that hot, humid air effectively inactivates B. anthracis ?Sterne and B. thuringiensis Al Hakam spores with similar kinetics.

Significance and Impact of the Study

Hot, humid air is a potential alternative to conventional chemical decontamination.     

Enhancement of solubility in <Emphasis Type="Italic">Escherichia coli</Emphasis> and purification of an aminotransferase from <Emphasis Type="Italic">Sphingopyxis</Emphasis> sp. MTA144 for deamination of hydrolyzed fumonisin B<Subscript>1</Subscript>

Background  

Fumonisin B₁ is a cancerogenic mycotoxin produced by Fusarium verticillioides and other fungi. Sphingopyxis sp. MTA144 can degrade fumonisin B₁, and a key enzyme in the catabolic pathway is an aminotransferase which removes the C2-amino group from hydrolyzed fumonisin B₁. In order to study this aminotransferase with respect to a possible future application in enzymatic fumonisin detoxification, we attempted expression of the corresponding fumI gene in E. coli and purification of the enzyme. Since the aminotransferase initially accumulated in inclusion bodies, we compared the effects of induction level, host strain, expression temperature, solubility enhancers and a fusion partner on enzyme solubility and activity.     

A meta‐analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum

Background

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta‐analysis of the topic.

Methods

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

Results

A total of 38 cross‐sectional and case‐control studies, with a total of 10 289 patients were eligible for review. Meta‐analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156‐1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

Limitations

Although the studies did not have high heterogeneity (I² = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin‐associated gene A gene.

Conclusion

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.     

Beneficial effect of Burdock complex on asymptomatic Helicobacter pylori‐infected subjects: A randomized,double‐blind placebo‐controlled clinical trial

Background

Burdock complex (BC) constitutes of burdock (Arctium lappa), angelica (Angelica sinensis), gromwell (Lithospermum erythrorhizon), and sesame (Sesamum indicum) oil, which are commonly used in traditional Chinese medicine (TCM) for treating various disorders. This study intended to examine the anti‐H. pylori activity of BC on AGS cell model as well as in asymptomatic H. pylori‐infected subjects.

Materials and Methods

AGS cell incubated with H. pylori and treated with BC to evaluate the minimum inhibition concentration (MIC), cell viability (MTT) anti‐adhesion activity, and inflammatory markers. In case of clinical trial, H. pylori‐positive subjects (urea breath test [UBT] >10%, n = 36) were enrolled and requested to intake BC (n = 19) or placebo (n = 17) for 8 weeks. Antioxidant capacity, total phenol, UBT, inflammatory markers were analyzed at the initial, 4th, 8th, and 10th weeks. Moreover, the endoscopic examination was carried out on baseline and 10th week.

Results

In vitro studies showed that BC treatment significantly inhibited (P < .05) the inflammatory markers and adhesion of H. pylori to AGS cell. However, H. pylori‐infected subject ingested with BC for 8 weeks significantly decreased (P < .05) the UBT value, inflammatory markers with improved antioxidant activity, and phenolic levels as compared to placebo. Also, consumption of BC considerably healed the ulcer wound.

Conclusion

Overall, the BC could attenuate H. pylori infection by inhibiting H. pylori adhesion and subsequent inflammatory response on the gastric epithelial cell (AGS) as well as clinically ameliorated UBT, antioxidant capacity, and alleviated inflammation to display its anti‐H. pylori activity.     

Global transcriptomic response of <Emphasis Type="Italic">Leptospira interrogans</Emphasis> serovar Copenhageni upon exposure to serum

Background  

Leptospirosis is a zoonosis of worldwide distribution caused by infection with pathogenic serovars of Leptospira spp. The most common species, L. interrogans, can survive in the environment for lengthy periods of time in between infection of mammalian hosts. Transmission of pathogenic Leptospira to humans mostly occurs through abraded skin or mucosal surfaces after direct or indirect contact with infected animals or contaminated soil or water. The spirochete then spreads hematogenously, resulting in multi-organ failure and death in severe cases. Previous DNA microarray studies have identified differentially expressed genes required for adaptation to temperature and osmolarity conditions inside the host compared to those of the environment.     

The SNF1-type serine-threonine protein kinase <Emphasis Type="Italic">SAPK4</Emphasis>regulates stress-responsive gene expression in rice

Background  

Plants respond to extracellularly perceived abiotic stresses such as low temperature, drought, and salinity by activation of complex intracellular signaling cascades that regulate acclimatory biochemical and physiological changes. Protein kinases are major signal transduction factors that have a central role in mediating acclimation to environmental changes in eukaryotic organisms. In this study, we characterized the function of the sucrose nonfermenting 1-related protein kinase2 (SnRK2) SAPK4 in the salt stress response of rice.     

The stress responsive and morphologically regulated <Emphasis Type="Italic">hsp90</Emphasis> gene from <Emphasis Type="Italic">Paracoccidioides brasiliensis</Emphasis> is essential to cell viability

Background  

Paracoccidioides brasiliensis is a dimorphic fungus that causes the most prevalent systemic mycosis in Latin America. The response to heat shock is involved in pathogenesis, as this pathogen switches from mycelium to yeast forms in a temperature dependent fashion that is essential to establish infection. HSP90 is a molecular chaperone that helps in the folding and stabilization of selected polypeptides. HSP90 family members have been shown to present important roles in fungi, especially in the pathogenic species, as an immunodominant antigen and also as a potential antifungal therapeutic target.