Prevention and control of highly antibiotic-resistant bacteria in a Pacific territory: Feedback from New Caledonia between 2004 and 2020.

OBJECTIVE: Carbapenemase-producing Enterobacteriaceae (CRE) and Enterococcus faecium resistant to vancomycin (VRE) constitute major threats to public health worldwide. The Pacific area is concerned and has implemented strategies to control antimicrobial resistance (AMR). However, accurate epidemiological data are rarely reported. Our study aimed to present the strategies applied to prevent and control the spread of highly resistant bacteria in the Pacific territory of New Caledonia. PATIENTS AND METHODS: Cohort prospective study of all cases of highly resistant bacteria (HRB) isolated in New Caledonia from September 2004 to December 2020. Evaluation of the impact of the infection control measures implemented in healthcare settings: screening strategy, cohorting unit, IT tools and control of antibiotic prescriptions. RESULTS: A total of 346 patients with HRB were identified. Most of them (63.0%) were infected or colonized by VRE (n=218) and 128 by CRE. While the number of CREs significantly increased from 2013 to 2020 (P<0.0001), control procedures have limited their dissemination. Most patients were colonized by IMP-4-CRE (n=124/128). The incidence density of VRE significantly decreased from 38.52 for 100,000 hospitalisation-days in 2015 to 4.19 for 100,000 hospitalisation-days in 2019 due to systematic screening of patients before sanitary repatriation from Australia and cohorting implementation. The risk of VRE diffusion is now well under control. CONCLUSIONS: Our study confirms that it is possible to control the spread of AMR in a circumscribed territory by means of a global control strategy involving screening, cohorting unit, IT tools and antibiotic prescription controls.

Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean.

A large retreat of sea-ice in the 'stormy' Atlantic Sector of the Arctic Ocean has become evident through a series of record minima for the winter maximum sea-ice extent since 2015. Results from the Norwegian young sea ICE (N-ICE2015) expedition, a five-month-long (Jan-Jun) drifting ice station in first and second year pack-ice north of Svalbard, showcase how sea-ice in this region is frequently affected by passing winter storms. Here we synthesise the interdisciplinary N-ICE2015 dataset, including independent observations of the atmosphere, snow, sea-ice, ocean, and ecosystem. We build upon recent results and illustrate the different mechanisms through which winter storms impact the coupled Arctic sea-ice system. These short-lived and episodic synoptic-scale events transport pulses of heat and moisture into the Arctic, which temporarily reduce radiative cooling and henceforth ice growth. Cumulative snowfall from each sequential storm deepens the snow pack and insulates the sea-ice, further inhibiting ice growth throughout the remaining winter season. Strong winds fracture the ice cover, enhance ocean-ice-atmosphere heat fluxes, and make the ice more susceptible to lateral melt. In conclusion, the legacy of Arctic winter storms for sea-ice and the ice-associated ecosystem in the Atlantic Sector lasts far beyond their short lifespan.

IAOOS microlidar-on-buoy development and first atmospheric observations obtained during 2014 and 2015 arctic drifts.

The in situ tests of first ever autonomous aerosol and cloud backscatter LIDAR (light detection and ranging) systems implemented on buoys for Arctic observations has been achieved in 2015 within the French EQUIPEX IAOOS project. The environmental and operational constraints were met by adopting a concept of a fibered microjoule lidar system using a laser diode. Two systems have been developed with and without polarization analysis capability. A specific optical design was used for polarization discrimination. These systems were integrated in buoys and tested in the Arctic in 2014 and 2015 at latitudes higher than 80°N. Data were transmitted through an Iridium space link. Measurements have been obtained 90% of the time from the non-polarized system in 2014 over 8 months as the first fully equipped buoy drifted from the Barneo Russian camp close to the North Pole toward Svalbard. A polarized system was then tested over a short period in winter 2015 north of Svalbard during the Norwegian campaign N-ICE. In April and May 2014, the unattended lidar measurements showed a large occurrence of aerosols and haze. The average attenuated scattering ratio for non-cloudy profiles during this period was about 2.2. Aerosols could reach an altitude of 5km on average, whereas over the rest of the period low level clouds (below 1000 m) were prevailing with an average attenuated scattering ratio of about 103. The main features of the developed lidar instruments and first results are presented here.

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice.

The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m-2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.

An autonomous nutrient analyzer for oceanic long-term in situ biogeochemical monitoring.

An autonomous nutrient analyzer in situ (ANAIS) has been developed to monitor nitrate, silicate, and phosphate concentrations while deployed at sea at pressure (down to 1000 m). Detection is made by spectrophotometry. The instrument uses solenoid-driven diaphragm pumps to propel the sample, the standards, and the reagents through a microconduit, flow injection-style thermostated manifold. The analyzers are placed in an equipressure container filled with oil. The analyzers operate until a pressure of 100 bar and show a linear response up to 40 microM nitrate, 150 microM silicate, and 5 microM phosphate with a detection limit less than 0.1, 0.5, and 0.1 microM and an accuracy of 1, 1, and 3% for nitrate, silicate, and phosphate, respectively. The measurement protocol includes three steps over 13 min: rinsing with the sample stream, reagents introduction, and absorbance detection. Field tests comprise ANAIS nitrate, silicate, and phosphate testing alone in the surface ocean. Phosphate results are not yet fully satisfactory. The instrument implemented on top of a YOYO vertical eulerian profiler was then deployed successfully in the northwestern Mediterranean Sea acquiring 30 nitrate profiles between 200 and 1100 m over a 15-day period. This chemical analyzer can be a valuable observing asset adapted on any type of oceanographic platform.