Intraguild predation involving Harmonia axyridis: a review of current knowledge and future perspectives

As an effective generalist predator of aphids and other hemipteran pests H. axyridis has been a successful biological control agent. However, the very functional traits that have contributed to its success in this regard also implicate it as an intraguild predator that poses a significant risk not only to the diversity of other natural enemies of Hemiptera (and their associated ecosystem services), but to biodiversity more widely. In this paper we will specifically review the existing data on intraguild predation involving H. axyridis, and consider the strength and symmetry of such interactions both within its native guild and within exotic guilds where it has established as an invasive alien. We will use these studies to interpret the observed population declines in predator diversity in the field, predict species at risk in regions not yet invaded and consider implications for resulting ecosystem services. We will also indicate gaps in our knowledge that require further study in order to identify opportunities for mitigation.     

Survival of Conidia of Clonostachys rosea on Stored Barley Seeds and Their Biocontrol Efficacy Against Seed-borne Bipolaris sorokiniana

Survival and biocontrol activity of Clonostachys rosea (isolate IK726) conidia during storage on barley seeds were investigated. The initial density of colony forming conidia on seed was 4 &#50 10 3 to 9 &#50 10 4 colony forming units (cfu)/seed. After 5 months storage at 4°C, the density decreased by less than one order of magnitude and the biocontrol efficacy against seedling blight caused by seed-borne Bipolaris sorokiniana was maintained at a significantly high level ( > 80% disease reduction) for > 5 months. Conidial survival on seeds stored at 20°C declined more rapidly than at 4°C, and biocontrol efficacy was significantly reduced after 3-5 months. However, conidia produced on solid media over 20 days survived better than conidia produced in liquid culture and conidia from solid media produced over 12 days. In contrast, when seeds treated with conidia were packed with silica gel and stored at 20°C, the cfu density decreased by less than one order of magnitude after 5 months and the biocontrol efficacy was still high after 6 months. A dose-response curve revealed that 103 cfu/seed were needed for 80% control of seedling blight. Similar control was obtained in storage experiments when approximately 103 cfu/seed were recovered from seed, indicating that conidia which survived also retained a high ability to control disease.     

Infective endocarditis: Role of molecular techniques in early diagnosis

Infective endocarditis (IE), a heart valve infection primarily caused by bacteria such as streptococci or staphylococci, causes significant morbidity and mortality. Despite the long-term use of broad-spectrum antimicrobials, the infection is often difficult to manage. The latest diagnostic modalities for IE are discussed in this study. Blood culture use in pathogen identification can lead to loss of precious time as well as generation of false negative reports. The first steps in diagnosis are blood cultures and echocardiography, but molecular techniques can be extremely useful and may be used for an accurate and early diagnosis.     

Control of pathogens and microbiota by innate lymphoid cells

Innate lymphoid cells (ILCs) are the innate counterpart of T cells. Upon infection or injury, ILCs react promptly to direct the developing immune response to the one most adapted to the threat facing the organism. Therefore, ILCs play an important role early in resistance to infection, but also to maintain homeostasis with the symbiotic microbiota following perturbations induced by diet and pathogens. Such roles of ILCs have been best characterized in the intestine and lung, mucosal sites that are exposed to the environment and are therefore colonized with diverse but specific types of microbes. Understanding the dialogue between pathogens, microbiota and ILCs may lead to new strategies to re-inforce immunity for prevention, vaccination and therapy.     

Simultaneous detection of pathogenic <Emphasis Type="Italic">B. cereus,S. aureus</Emphasis> and <Emphasis Type="Italic">L. monocytogenes</Emphasis> by multiplex PCR

Three important foodborne pathogens, Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus are of major concern for food safety in terms of frequency and seriousness of the disease. The occurrence these three important pathogens and their coexistence in food matrices are predominant. Moreover, symptoms associated with B. cereus and S. aureus food poisoning not only closely resembles each other but can also be overlapping with other foodborne infections. In this context, detection of these three pathogens simultaneously in food samples by a single multiplex PCR (mPCR) would have advantages in terms of rapidity and cost saving, when compared with single organism specific PCRs. mPCR has been standardized by targeting three major diarrheal enterotoxin genes hbl A, cyt K and nhe A of B. cereus, virulence associated nuc and Ent B genes of S. aureus and virulence associated hly and iap genes of L. monocytogenes along with internal amplification control (IAC). The results showed that mPCR accurately identified all the three organisms individually or in combination without non-specificity. The mPCR was able to detect as low as 10 to 100 organisms per ml of growth following overnight enrichment of spiked food samples (vegetable biriyani and milk) and their presence in naturally contaminated samples also. The high throughput and cost effective multiplex PCR method developed in this study could provide a powerful tool for simultaneous, rapid and reliable detection of B. cereus, S. aureus and L. monocytogenes in food samples.     

Perspective: Microfluidic applications in microbiology

The application of microfluidics technology to microbiology research is an excellent platform for the analysis of microorganisms and their nucleic acids. This technology combines engineering, physics, chemistry, biology and computing to control the devices. In this perspective we discuss how microfluidics can be applied to microbiological research and used in diagnostic applications. We also summarize advantages and limitations of this technology, as well as highlight some recent microbiological applications.     

A systematic bioinformatics approach for selection of epitope-based vaccine targets

Epitope-based vaccines provide a new strategy for prophylactic and therapeutic application of pathogen-specific immunity. A critical requirement of this strategy is the identification and selection of T-cell epitopes that act as vaccine targets. This study describes current methodologies for the selection process, with dengue virus as a model system. A combination of publicly available bioinformatics algorithms and computational tools are used to screen and select antigen sequences as potential T-cell epitopes of supertype human leukocyte antigen (HLA) alleles. The selected sequences are tested for biological function by their activation of T-cells of HLA transgenic mice and of pathogen infected subjects. This approach provides an experimental basis for the design of pathogen specific, T-cell epitope-based vaccines that are targeted to majority of the genetic variants of the pathogen, and are effective for a broad range of differences in human leukocyte antigens among the global human population.     

Diversity and phylogenetic relationships of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) from the Sky Islands of Southern Arizona

A survey for entomopathogenic nematodes was conducted in oak-juniper woodlands of four mountain ranges (Santa Rita, Santa Catalina, Pinale?o, and Chiricahuas), in southeastern Arizona. From a total of 120 soil samples, 23.3% were EPN-positive. Of them 78.5% were positive for Steinernema spp. and 21.5% were positive for Heterorhabditis spp. An integrated approach, combining both traditional (morphological) and molecular methods, was used for examining the diversity of species of these entomopathogenic nematodes. Two named-species S. oregonense and S. riobrave are reported for the first time in Arizona, expanding their currently known geographic range. In addition to this, three undescribed Steinernema and three Heterorhabditis spp. were recovered. Insular evolution, in part, could account for the geographic distribution of entomopathogenic nematodes in Arizona.