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Hitchhikers (phoretic organisms) need vehicles to disperse out of unsuitable habitats. Therefore, finding vehicles with the right functional attributes is essential for phoretic organisms. To locate these vehicles, phoretic organisms employ cues within modalities, ranging from visual to chemical senses. However, how hitchhikers discriminate between individual vehicles has rarely been investigated. Using a phoretic nematode community associated with an obligate fig-fig wasp pollination mutualism, we had earlier established that hitchhiking nematodes make decisions based on vehicle species identity and number of conspecific hitchhikers already present on the vehicle. Here we investigate if hitchhikers can differentiate between physiological states of vehicles. We asked whether phoretic nematodes choose between live or dead vehicles present in a chemically crowded environment and we investigated the basis for any discrimination. We conducted two-choice and single-choice behavioral assays using single nematodes and found that plant- and animal-parasitic nematodes preferred live over dead vehicles and used volatiles as a sensory cue to make this decision. However, in single-choice assays, animal-parasitic nematodes were also attracted towards naturally dead or freeze-killed wasps. The volatile profile of the wasps was dominated by terpenes and spiroketals. We examined the volatile blend emitted by the different wasp physiological states and determined a set of volatiles that the phoretic nematodes might use to discriminate between these states which is likely coupled with respired CO2. We determined that CO2 levels emitted by single wasps are sufficient to attract nematodes, demonstrating the high sensitivity of nematodes to this metabolic product.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Domiasiat (25°30′N 91°30′E) located in the west Khasi hill district of Meghalaya in northeast India is one of the largest sandstone-type uranium (U) ore deposit in India containing 9.22 million tonnes of ore reserves with an average ore grade of around 0.1 % U3O8. This geographically distinct U deposit of Domiasiat is un-mined and harbours diverse group of bacteria surviving the stressful environmental conditions prevalent in the ore deposit. Studies show that the diverse bacteria belonged to 10 different bacterial groups with occurrence of some previously uncharacterized bacteria. The cultured identified bacteria have been reported to tolerate substantial concentration of U and other metals and showed potent capacity for uptake and precipitation of U. Studying the bacterial community associated with such pre-mined U ore deposit are advantageous as it not only generates the baseline information on microbial community structure as resourceful indicator to estimate the impact of mining to be undertaken in future but also identifies the bacteria which can be explored for their potential as bioremediation agents for radionuclide/multi-metal waste sites.

Aims To assess whether the yew roots, which are able to provide a very constant environment due to their long life-span, can maintain the original arbuscular mycorrhizal (AM) fungal community during yew population decline.

Bacterial species associated with the dimethylsulfoniopropionate (DMSP)-producing phytoplankton Scrippsiella trochoidea were cultured and identified, with the aim of establishing their ability to metabolise DMSP, dimethylsulfide (DMS) and dimethylsulfoxide (DMSO). Results demonstrate that of the cultivable bacteria only α-Proteobacteria were capable of producing DMS from DMSP. The concentration of DMSP was shown to affect the amount of DMS produced. Lower DMSP concentrations (1.5 μmol dm−3) were completely assimilated, whereas higher concentrations (10 μmol dm−3) resulted in increasing amounts of DMS being produced. By contrast to the restricted set of bacteria that metabolised DMSP, ~ 70% of the bacterial isolates were able to ‘consume’ DMS. However, 98-100% of the DMS removed was accounted for as DMSO. Notably, a number of these bacteria would only oxidise DMS in the presence of glucose, including members of the γ-Proteobacteria and Bacteroidetes. The observations from this study, coupled with published field data, identify DMS oxidation to DMSO as a major transformation pathway for DMS, and we speculate that the fate of DMS and DMSP in the field are tightly coupled to the available carbon produced by phytoplankton.

There is increasing recognition of the importance of community-associated Clostridium difficile infection (CA-CDI) despite little being known about its epidemiology. We performed routine, active laboratory surveillance for CDI at the Durham Veterans Affairs Medical Center between January and December 2005 and extracted data from the electronic medical record for this investigation. Bivariable analyses were performed using the chi-square test, and continuous variables were compared using two sample t test and Wilcoxon rank sums. We identified 108 CDI cases during the study period; 38 (35%) had onset of disease in the community and, of these, 31 (82%) met the definition for CA-CDI. A comparison of CA- versus healthcare facility-associated (HCFA)-CDI revealed that CA-CDI patients were younger (median age 58 vs. 69 years, respectively; p = 0.01), with the majority being

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasingly common in the USA, but rare in the UK. We compared CA-MRSA from the UK and USA to examine differences in the molecular epidemiology. We investigated patients presenting with MRSA in the first 72 h of hospital admission or in out-patient settings in a UK and a US hospital from January 2004 to March 2006. Fluoroquinolone susceptibility was used as a screening marker to select presumptive CA-MRSA. One hundred and eighteen and 49 such strains were identified, representing a prevalence of 0.1 and 0.2 isolates per 1,000 patient days in the UK and US respectively. Panton-Valentine leukocidin (PVL)-positive ST8-IVa (USA300)-type strains predominated among 43 surviving US isolates, whereas PVL-negative ST1-IVa predominated among 71 surviving UK isolates. There are striking differences between the molecular epidemiology of CA-MRSA in UK and US hospitals, which may have implications for control.

The diet of non-breeding male Antarctic fur seals, Arctocephalus gazella, was investigated at Stranger Point, King George Island, through the analysis of scats during three consecutive summer seasons (1996, 1997, 1998). Overall, fish and krill were the most frequent prey occurring, respectively, in an average of 82.9% and 78.8% of samples (n = 131), followed by penguins (22.8%) and cephalopods (17.8%). Myctophids constituted almost 90% of the fish predated, with Electrona antarctica and Gymnoscopelus nicholsi being the most abundant and frequent species consumed. All fish taxa identified were krill feeding species suggesting that seals foraged mainly on a krill and a fish community associated with krill aggregations. However, a seasonal change was observed in the relative proportions of the different prey taxa, with a progressive decrease with time in the occurrence of krill and a concomitant increase of fish, penguins and squid. Possible influence of the strong 1997/98 ENSO event is discussed. Fil: Daneri, Gustavo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Carlini, A. R.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina Fil: Harrington, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Balboni, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Hernandez, C.M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina

Methicillin-resistant Staphylococcus aureus has emerged in the community among patient populations without traditional antibiotic resistance risk factors and is causing a variety of clinical syndromes, in particular skin and soft tissue infections. These infections can range from minor skin involvement that can be treated in an outpatient setting to more serious infections such as necrotizing fasciitis requiring hospitalization. Inpatient and outpatient healthcare providers must be aware of the treatment, prevention, and infection control practices for this emerging pathogen.

The prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased alarmingly in both the general population and the HIV-infected community. We look at the background of MRSA including the mechanisms of resistance, genetics, and trends in the individual with HIV infection. Numerous studies have investigated the risk factors for CA-MRSA. Other studies have further characterized the incidence of and risk factors for MRSA infections in the HIV community. Although one might not readily associate advanced HIV infection with increased susceptibility to bacterial pathogens, a number of studies have explained the mechanisms of this B-cell-mediated susceptibility. Invasive MRSA infections have spread into communities, are increasingly prevalent, and pose a public health challenge for their containment, prevention, and treatment.

Background We characterized 100 USA100 epidemic MRSA from individuals in the community with no known healthcare-associated risk factors. Findings Molecular epidemiology demonstrated 21 pulsed-field types and six spa types. SCCmec typing demonstrated that all of the strains possess the type II cassette. The staphylococcal enterotoxin D virulence gene was also present. Conclusion Characterization of USA100 MRSA in the community illustrated the importance of nasal carriage, and the genetic diversity of the USA100 clone.

The present work deals with the temporal and bathymetrical variations of the epifaunal community associated with two species of pearl oysters (Pinctada mazatlanica and Pteria sterna) during a seed collecting season from June to November 1989. A total of 63 items (species, genera and/or families) were recorded; their variations in presence and abundance were followed during three periods (June–July, August–September and October–November). The collectors were examined for different immersion times (2, 4, 6 and 8 weeks) for each period. Community structure was compared through the Brillouin Index, the Morisita Index and the Importance Value.

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem in the Americas and the Caribbean including Cuba. Recently, MRSA isolates are emerging as significant pathogens in the community. In the USA, the most prevalent community associated (CA-)MRSA clone is USA300 (ST8, spa type 008). Little is known about the molecular epidemiology of MRSA in some of the Caribbean countries. In this study we aim to investigate the molecular epidemiology of MRSA isolates from 4 major Cuban hospitals.