The study of bacterial virulence often requires a suitable animal model. Mammalian models of infection are costly and may raise ethical issues. The use of insects as infection models provides a valuable alternative. Compared to other non-vertebrate model hosts such as nematodes, insects have a relatively advanced system of antimicrobial defenses and are thus more likely to produce information relevant to the mammalian infection process. Like mammals, insects possess a complex innate immune system 1 . Cells in the hemolymph are capable of phagocytosing or encapsulating microbial invaders, and humoral responses include the inducible production of lysozyme and small antibacterial peptides 2,3 . In addition, analogies are found between the epithelial cells of insect larval midguts and intestinal cells of mammalian digestive systems. Finally, several basic components essential for the bacterial infection process such as cell adhesion, resistance to antimicrobial peptides, tissue degradation and adaptation to oxidative stress are likely to be important in both insects and mammals 1 . Thus, insects are polyvalent tools for the identification and characterization of microbial virulence factors involved in mammalian infections.Larvae of the greater wax moth Galleria mellonella have been shown to provide a useful insight into the pathogenesis of a wide range of microbial infections including mammalian fungal (Fusarium oxysporum, Aspergillus fumigatus, Candida albicans) and bacterial pathogens, such as Staphylococcus aureus, Proteus vulgaris, Serratia marcescens Pseudomonas aeruginosa, Listeria monocytogenes or Enterococcus faecalis [4][5][6][7] . Regardless of the bacterial species, results obtained with Galleria larvae infected by direct injection through the cuticle consistently correlate with those of similar mammalian studies: bacterial strains that are attenuated in mammalian models demonstrate lower virulence in Galleria, and strains causing severe human infections are also highly virulent in the Galleria model [8][9][10][11] . Oral infection of Galleria is much less used and additional compounds, like specific toxins, are needed to reach mortality.G. mellonella larvae present several technical advantages: they are relatively large (last instar larvae before pupation are about 2 cm long and weight 250 mg), thus enabling the injection of defined doses of bacteria; they can be reared at various temperatures (20 °C to 30 °C) and infection studies can be conducted between 15 °C to above 37 °C 12,13 , allowing experiments that mimic a mammalian environment. In addition, insect rearing is easy and relatively cheap. Infection of the larvae allows monitoring bacterial virulence by several means, including calculation of LD 50 14 , measurement of bacterial survival 15,16 and examination of the infection process 17 . Here, we describe the rearing of the insects, covering all life stages of G. mellonella. We provide a detailed protocol of infection by two routes of inoculation: oral and intra haemocoelic. The bacterial...

This study examined the effect of an integrated yoga programme on chemotherapy-related nausea and emesis in early operable breast cancer outpatients. Sixty-two subjects were randomly allocated to receive yoga (n = 28) or supportive therapy intervention (n = 34) during the course of their chemotherapy. Both groups had similar socio-demographic and medical characteristics. Intervention consisted of both supervised and home practice of yoga sessions lasting for 60 min daily, while the control group received supportive therapy and coping preparation during their hospital visits over a complete course of chemotherapy. The primary outcome measure was the Morrow Assessment of Nausea and Emesis (MANE) assessed after the fourth cycle of chemotherapy. Secondary outcomes included measures for anxiety, depression, quality of life, distressful symptoms and treatment-related toxicity assessed before and during the course of chemotherapy. Following yoga, there was a significant decrease in post-chemotherapy-induced nausea frequency (P = 0.01) and nausea intensity (P = 0.01), and intensity of anticipatory nausea (P = 0.01) and anticipatory vomiting (P = 0.05) as compared with the control group. There was a significant positive correlation between MANE scores and anxiety, depression and distressful symptoms. In conclusion, the results suggest a possible use for stress reduction interventions such as yoga in complementing conventional antiemetics to manage chemotherapy-related nausea and emesis.

Objectives. This study compares the effects of an integrated yoga program with brief supportive therapy in breast cancer outpatients undergoing adjuvant radiotherapy at a cancer center. Methods. Eighty-eight stage II and III breast cancer outpatients are randomly assigned to receive yoga (n = 44) or brief supportive therapy (n = 44) prior to radiotherapy treatment. Assessments include diurnal salivary cortisol levels 3 days before and after radiotherapy and self-ratings of anxiety, depression, and stress collected before and after 6 weeks of radiotherapy. Results. Analysis of covariance reveals significant decreases in anxiety ( P < .001), depression ( P = .002), perceived stress ( P < .001), 6 a.m. salivary cortisol ( P = .009), and pooled mean cortisol ( P = .03) in the yoga group compared with controls. There is a significant positive correlation between morning salivary cortisol level and anxiety and depression. Conclusion. Yoga might have a role in managing self-reported psychological distress and modulating circadian patterns of stress hormones in early breast cancer patients undergoing adjuvant radiotherapy.

How pathogenic bacteria infect and kill their host is currently widely investigated. In comparison, the fate of pathogens after the death of their host receives less attention. We studied Bacillus thuringiensis ( Bt ) infection of an insect host, and show that NprR, a quorum sensor, is active after death of the insect and allows Bt to survive in the cadavers as vegetative cells. Transcriptomic analysis revealed that NprR regulates at least 41 genes, including many encoding degradative enzymes or proteins involved in the synthesis of a nonribosomal peptide named kurstakin. These degradative enzymes are essential in vitro to degrade several substrates and are specifically expressed after host death suggesting that Bt has an active necrotrophic lifestyle in the cadaver. We show that kurstakin is essential for Bt survival during necrotrophic development. It is required for swarming mobility and biofilm formation, presumably through a pore forming activity. A nprR deficient mutant does not develop necrotrophically and does not sporulate efficiently in the cadaver. We report that necrotrophism is a highly regulated mechanism essential for the Bt infectious cycle, contributing to spore spreading.

Insects are the largest group of animals on earth. Like mammals, virus, fungi, bacteria and parasites infect them. Several tissue barriers and defense mechanisms are common for vertebrates and invertebrates. Therefore some insects, notably the fly Drosophila and the caterpillar Galleria mellonella, have been used as models to study host-pathogen interactions for several insect and mammal pathogens. They are excellent tools to identify pathogen determinants and host tissue cell responses. We focus here on the comparison of effectors used by two different groups of bacterial insect pathogens to accomplish the infection process in their lepidopteran larval host: Bacillus thuringiensis and the nematode-associated bacteria, Photorhabdus and Xenorhabdus. The comparison reveals similarities in function and expression profiles for some genes, which suggest that such factors are conserved during evolution in order to attack the tissue encountered during the infection process.

The Bacillus cereus sensu lato group contains diverse Gram-positive spore-forming bacteria that can cause gastrointestinal diseases and severe eye infections in humans. They have also been incriminated in a multitude of other severe, and frequently fatal, clinical infections, such as osteomyelitis, septicaemia, pneumonia, liver abscess and meningitis, particularly in immuno-compromised patients and preterm neonates. The pathogenic properties of this organism are mediated by the synergistic effects of a number of virulence products that promote intestinal cell destruction and/or resistance to the host immune system. This review focuses on the pore-forming haemolysins produced by B. cereus: haemolysin I (cereolysin O), haemolysin II, haemolysin III and haemolysin IV (CytK). Haemolysin I belongs to the cholesterol-dependent cytolysin (CDC) family whose best known members are listeriolysin O and perfringolysin O, produced by L. monocytogenes and C. perfringens respectively. HlyII and CytK are oligomeric ß-barrel pore-forming toxins related to the α-toxin of S. aureus or the ß-toxin of C. perfringens. The structure of haemolysin III, the least characterized haemolytic toxin from the B. cereus, group has not yet been determined.

Bacillus cereus is the 2nd most frequent bacterial agent responsible for food-borne outbreaks in France and the 3rd in Europe. In addition, local and systemic infections have been reported, mainly describing individual cases or single hospital setting. The real incidence of such infection is unknown and information on genetic and phenotypic characteristics of the incriminated strains is generally scarce. We performed an extensive study of B. cereus strains isolated from patients and hospital environments from nine hospitals during a 5-year study, giving an overview of the consequences, sources and pathogenic patterns of B. cereus clinical infections. We demonstrated the occurrence of several hospital-cross-contaminations. Identical B. cereus strains were recovered from different patients and hospital environments for up to 2 years. We also clearly revealed the occurrence of inter hospital contaminations by the same strain. These cases represent the first documented events of nosocomial epidemy by B. cereus responsible for intra and inter hospitals contaminations. Indeed, contamination of different patients with the same strain of B. cereus was so far never shown. In addition, we propose a scheme for the characterization of B. cereus based on biochemical properties and genetic identification and highlight that main genetic signatures may carry a high pathogenic potential. Moreover, the characterization of antibiotic resistance shows an acquired resistance phenotype for rifampicin. This may provide indication to adjust the antibiotic treatment and care of patients.

Gastric infections by Helicobacter pylori are characteristically associated with an intense inflammation and infiltration of mainly polymorphonuclear lymphocytes (PMNs) and monocytes. The inflammatory response by infiltrated immune cells appears to be a primary cause of the damage to surface epithelial layers and may eventually result in gastritis, peptic ulcer, gastric cancer and/or MALT‐associated gastric lymphoma. Our analysis of the interaction between H. pylori and PMNs and monocytes revealed that H. pylori inhibits its own uptake by these professional phagocytes. To some degree, this effect resembles antiphagocytosis by Yersinia enterocolitica. Increasing numbers of bacteria associated per cell are more efficient at blocking their own engulfment. In H. pylori, bacterial protein synthesis is necessary to block phagocytic uptake, as shown by the time and concentration dependence of the bacteriostatic protein synthesis inhibitor chloramphenicol. Furthermore, H. pylori appears broadly to inhibit the phagocytic function of monocytes and PMNs, as infection with H. pylori abrogates the phagocytes' ability to engulf latex beads or adherent Neisseria gonorrhoeae cells. This antiphagocytic phenotype depends on distinct virulence (vir) genes, such as virB7 and virB11, encoding core components of a putative type IV secretion apparatus. Our data indicate that H. pylori exhibits an antiphagocytic activity that may play an essential role in the immune escape of this persistent pathogen.