The safety of Bacillus subtilis and Bacillus indicus as food probiotics

Aims:  To conduct in vitro and in vivo assessments of the safety of two species of Bacillus , one of which, Bacillus subtilis , is in current use as a food supplement.
Methods and Results:  Cultured cell lines, Caco-2, HEp-2 and the mucus-producing HT29-16E cell line, were used to evaluate adhesion, invasion and cytotoxicity. The Natto strain of B. subtilis was shown to be able to invade and lyse cells. Neither species was able to adhere significantly to any cell line. The Natto strain was also shown to form biofilms. No strain produced any of the known Bacillus enterotoxins. Disc-diffusion assays using a panel of antibiotics listed by the European Food Safety Authority (EFSA) showed that only Bacillus indicus carried resistance to clindamycin at a level above the minimum inhibitory concentration breakpoints set by the EFSA. In vivo assessments of acute and chronic dosing in guinea pigs and rabbits were made. No toxicity was observed in animals under these conditions.
Conclusions:  Bacillus indicus and B. subtilis should be considered safe for oral use although the resistance of B. indicus to clindamycin requires further study.
Significance and Impact of the Study:  The results support the use of B. subtilis and B. indicus strains as food supplements.     

Factors affecting refuge from parasitoid attack in a cynipid wasp, Aphelonyx glanduliferae

We examined seasonal patterns of gall morphology, growth, and survivorship of the agamic generation of a cynipid wasp, Aphelonyx glanduliferae, and discussed its mortality factors, especially from the point of view of refuge from parasitoid attack. Although the initiation period varied greatly among individual galls, the larvae of A. glanduliferae grew rapidly and reached their maximum size within 3 weeks before pupating in late September to early October. This growth period corresponded to the period when the gall walls became thinner. Parasitoid attack, which was the principal factor in the mortality of A. glanduliferae in the tree crown, was concentrated around the pupation period of the cynipid. Gall walls were significantly thinner in galls attacked by parasitoids than in those still containing a living cynipid. Therefore, the period available to parasitoids seems to be limited by both gall wall thickness and cynipid size. Thus, the growth pattern of A. glanduliferae larvae can have significance in that it narrows the window of vulnerability to parasitoids to a particular period. Although delaying gall initiation will also shorten the exposure period to parasitoid attacks, it was likely to increase the risk of death from gall abortion caused by seasonal degradation in the quality of host plant tissues. Although many cynipids were killed by disease in the galls that fell to the ground, the falling of mature galls to the ground may be another way to a parasitoid-free space. It is thus suggested that a trade-off among life history traits against multiple factors operates in the refuge of A. glanduliferae from parasitoid attack. Received: May 15, 2001 / Accepted: February 1, 2002     

Phylogeny of the Baldratiina (Diptera: Cecidomyiidae) inferred from morphological, ecological and molecular data sources, and evolutionary patterns in plant-galler relationships

The phylogeny of the gall-midge subtribe Baldratiina (Diptera: Cecidomyiidae) was reconstructed from molecular (partial sequence of the mitochondrial 12S rDNA), morphological and ecological data sets, using 16 representative species of most of the genera. The morphological and ecological data were combined in a single character matrix and analyzed separately from the molecular data, resulting in an eco-morphological cladogram and a molecular cladogram. Attributes of galls and host associations were superimposed on the molecular cladogram in order to detect possible trends in the evolution of these traits. The cladograms resulting from the two independent analyses were statistically incongruent, although both provide evidence for the monophyly of the genera Baldratia and Careopalpis and the paraphyly of the genera Stefaniola and Izeniola. The results suggest a minor impact of the morphological characters traditionally used in the classification of the Baldratiina, whereas ecological data had a major impact on the phylogenetic inference. Mapping of gall and host attributes on the molecular cladogram suggests that multi-chambered stem galls constitute the ancestral state in the subtribe, with several subsequent shifts to leaf galls. It is concluded that in contrast to other studied groups of gall insects, related baldratiine species induce different types of galls, attesting to speciation driven by gall-type shifts at least as often as host shifts.     

Plant Parasitic Nematodes: Habitats, Hormones, and Horizontally-Acquired Genes

Abstract Plant parasitic nematodes are ubiquitous and cosmopolitan pathogens of vascular plants and exploit all parts of the roots and shoots, causing substantial crop damage. Nematodes deploy a broad spectrum of feeding strategies, ranging from simple grazing to the establishment of complex cellular structures (including galls) in host tissues. Various models of feeding site formation have been proposed, and a role for phytohormones has long been speculated, although whether they perform a primary or secondary function is unclear. On the basis of recent molecular evidence, we present several scenarios involving phytohormones in the induction of giant cells by root-knot nematode. The origin of parasitism by nematodes, including the acquisition of genes to synthesize or modulate phytohormones also is discussed, and models for horizontal gene transfer are presented.     

The first record of genus Bruggmanniella (Diptera: Cecidomyiidae) from Taiwan with description of a new species inducing bud galls on Neolitsea parvigemma (Lauraceae)

The genus Bruggmanniella Tavares is newly discovered from Taiwan and Bruggmanniella brevipes sp. n. is described as new to science. This is the southernmost species of Bruggmanniella found in the Old World. Furthermore, the gall midge induces bud galls on Neolitsea parvigemma (Hayata) Kaneh (Lauraceae), an endemic species in Taiwan, and the plant genus Neolitsea is the third host genus of Lauraceae-associated Bruggmanniella in East Asia. The knowledge of its distribution and host information provide us to shed the light on evolutionary and biogeography issue of East Asian Bruggmanniella.www.zoobank.org/urn:lsid:zoobank.org:pub:820320EC-17BC-4E00-A401-2DBDA3EEE9C4     

Adaptive significance of gall formation for a gall-inducing aphids on Japanese elm trees

Insect galls are abnormal plant tissues induced by external stimuli from parasitizing insects. It has been suggested that the stimuli include phytohormones such as auxin and cytokinins produced by the insects. In our study on the role of hormones in gall induction by the aphid Tetraneura nigriabdominalis, it was found that feedback regulation related to auxin and cytokinin activity is absent in gall tissues, even though the aphids contain higher concentrations of those phytohormones than do plant tissues. Moreover, jasmonic acid signaling appears to be compromised in gall tissue, and consequently, the production of volatile organic compounds, which are a typical defense response of host plants to herbivory, is diminished. These findings suggest that these traits of the gall tissue benefit aphids, because the gall tissue is highly sensitive to auxin and cytokinin, which induce and maintain it. The induced defenses against aphid feeding are also compromised. The abnormal responsiveness to phytohormones is regarded as a new type of extended phenotype of gall-inducing insects.     

Gut microbial composition in developmental stages of gall inducing thrips Gynaikothrips uzeli and associated plant pathogenesis

Gut bacteria play a crucial role in the several metabolic activity of the insects. In the present work, effort has been made to decipher the gut microbiota associated with the developmental stages of Gynaikothrips uzeli a gall inducing thrips along with their predicted functional role. Further, an effort has been made to correlate the bacterial communities with plant pathogenesis and thelytoky behaviour of G. uzeli. Findings obtained revealed that genus Arsenophonus dominated the total bacterial diversity and was transmitted vertically through the developmental stages. Further, it was observed that the high abundance of genus Arsenophonus promotes the thelytoky behaviour in G. uzeli and results in the killing of males. Furthermore, strong connecting link between Arsenophonus abundance and gall induction in F. benjamina was observed in the current dataset. G. uzeli being in the category of phloem sucking insect was known for the induction of galls and the current findings for the first time unveiled the facts that high abundance of genus Arsenophonus a well-known plant pathogen may be one of the major reason for inducing galls in F. benjamina. Moreover, PICRUSt2 analysis revealed that predicted functional pathways like biosynthesis of amino acids, and metabolism of carbon, nitrogen, carbohydrates and amino acids (e.g. Arginine, Alanine, Aspartate, Glutamate, Proline, Cysteine, Methionine, Glycine, Threonine, and Serine) were frequently noticed in profiles associated with all the developmental stages of G. uzeli. More to this, the high abundance of Arsenophonus in G. uzeli suggest that representatives of this genus may be resistant and/or tolerant to different antibacterial agents, alkaloids, flavonoids, and glycosides (e.g. quercetin). The correlation of bacterial diversity in pathogenicity can be extrapolated in different pest and vector species of other arthropods.     

Differences in volatile emissions between healthy and gall-induced branches of Haplopappus foliosus (Asteraceae)

Changes in plant secondary metabolism due to insect galls are one of the frontiers in knowledge of plant-insect interactions, especially concerning volatile organic compounds (VOCs). Here we studied the in vivo VOCs released from healthy apical branches of Haplopappus foliosus DC. (Asteraceae) and compared these volatiles to the VOCs obtained from apical bud galls produced in this host plant when attacked by the gall midge Haplopappusmyiia gregaria (Cecidomyiidae). We field-collected VOCs by dynamic headspace and identified them by gas chromatography coupled to mass spectrometry. We found changes in the relative proportions of different classes of VOC in apical branches vs. apical bud galls. H. foliosus VOCs had mainly monoterpene hydrocarbons such as p-cymene, a recognized herbivore deterrent. We also found oxygenated monoterpenes and sesquiterpenes in the H. foliosus volatile mixture. H. foliosus modifies its fragrance composition when parasitized by gall midges, showing an increased proportion of some monoterpene hydrocarbons, e.g. limonene and camphene, while others such as α-thujene, p-cymene and γ-terpinene were down-expressed in apical bud gall VOCs. We discuss these results considering gall signaling and chemical ecology hypotheses, including the potential role of plant defenses as well as gall midge-derived modification for host plant VOCs, and comment on the ecological relevance of our findings.     

腹腔镜联合微创保胆取石术治疗胆囊结石的疗效和安全性分析

目的:观察腹腔镜联合微创保胆取石术治疗胆囊结石的临床疗效,并对其安全性进行分析.方法:按不同治疗方法将80例胆囊结石合患者分为两组,观察组46例,采用腹腔镜联合微创保胆取石术,对照组34例,采用传统切开胆囊胆总管取石术.结果:观察组的手术时间93.7±17.0 min明显小于对照组的118.7±10.6 min(P＜0.05);观察组的术中出血量91.7±27.3 mL明显小于对照组的142.7± 17.0 mL(P＜0.05);观察组的肛门排气时间及住院时间明显小于对照组的(P＜0.05);观察组的切口感染率4.3％明显小于对照组17.6％(＜0.05);观察组的结石复发率2.2％明显小于对照组的14.7％(P＜0.05).结论:腹腔镜联合微创保胆取石术治疗胆囊结石的疗效良好,能缩短手术时间,减少术中出血量,提高了安全可靠性,有利于患者术后康复.