Epidemiological cut-off values for Yersina ruckeri disc diffusion data generated by a standardised method

In order to establish the meaning of data generated in antimicrobial agent susceptibility tests, it is necessary to develop internationally harmonised interpretive criteria. Currently, such criteria have not been developed for data generated in studies of the susceptibility of the fish pathogen Yersinia ruckeri. This work generated the data that would be required to set epidemiological cut-off values for the susceptibility data of this species that had been generated using a standardised disc diffusion method that specified the use of Mueller Hinton agar and incubation at 22°C for 24-28 h. Using this method, sets of inhibition zones data for 4 antimicrobial agents were generated by 3 independent laboratories. The data from these laboratories were aggregated and analysed using the statistically based normalised resistance interpretation. For ampicillin, florfenicol, oxytetracycline and trimethoprim-sulfamethoxazole the cut-off values calculated by this analysis were ≥16, ≥23, ≥24 and ≥30 mm, respectively. Evidence is presented demonstrating that the data for these 4 agents was of sufficient quantity and quality that they could be used by the relevant authorities to set internationally harmonised, consensus epidemiological cut-off values for Y. ruckeri.

A systematic approach toward progressive improvement of national antimicrobial resistance surveillance systems in food and agriculture sectors

The first Food and Agriculture Organization of the United Nations (FAO) Action Plan on antimicrobial resistance (AMR), published in 2016, identified the need to develop capacity for AMR surveillance and monitoring in food and agriculture sectors. As part of this effort, FAO has developed the "Assessment Tool for Laboratories and AMR Surveillance Systems" (FAO-ATLASS) to assist countries in systematically assessing their AMR surveillance system in food and agriculture. FAO-ATLASS includes two different modules for surveillance and laboratory assessment. Each module includes two questionnaires that collect either qualitative or semi-quantitative data to describe and score the performance of national AMR surveillance system data production network, data collection and analysis, governance, communication and overall sustainability in a standardized manner. Based on information captured in the questionnaire by trained assessors (1) tables and figures describing the outputs of the surveillance system are automatically generated (2) a Progressive Improvement Pathway (PIP) stage, ranging from "1-limited" to "5-sustainable", is assigned to each laboratory assessed in the country, each area of the surveillance system and also to the overarching national AMR surveillance system. FAO-ATLASS allows national authorities to implement a strategic stepwise approach to improving their AMR surveillance systems via the FAO-ATLASS PIP system and provides an evidence base for actions and advocacy. The implementation of FAO-ATLASS at regional and global levels can contribute to harmonize and better coordinate strategies aimed at implementing an integrated AMR surveillance system under the One Health approach.

External quality assessment of Rift Valley fever diagnosis in countries at risk of the disease: African, Indian Ocean and Middle-East regions

Rift Valley fever virus (RVFV), an arbovirus belonging to the Phlebovirus genus of the Phenuiviridae family, causes the zoonotic and mosquito-borne RVF. The virus, which primarily affects livestock (ruminants and camels) and humans, is at the origin of recent major outbreaks across the African continent (Mauritania, Libya, Sudan), and in the South-Western Indian Ocean (SWIO) islands (Mayotte). In order to be better prepared for upcoming outbreaks, to predict its introduction in RVFV unscathed countries, and to run efficient surveillance programmes, the priority is harmonising and improving the diagnostic capacity of endemic countries and/or countries considered to be at risk of RVF. A serological inter-laboratory proficiency test (PT) was implemented to assess the capacity of veterinary laboratories to detect antibodies against RVFV. A total of 18 laboratories in 13 countries in the Middle East, North Africa, South Africa, and the Indian Ocean participated in the initiative. Two commercial kits and two in-house serological assays for the detection of RVFV specific IgG antibodies were tested. Sixteen of the 18 participating laboratories (88.9%) used commercial kits, the analytical performance of test sensitivity and specificity based on the seroneutralisation test considered as the reference was 100%. The results obtained by the laboratories which used the in-house assay were correct in only one of the two criteria (either sensitivity or specificity). In conclusion, most of the laboratories performed well in detecting RVFV specific IgG antibodies and can therefore be considered to be prepared. Three laboratories in three countries need to improve their detection capacities. Our study demonstrates the importance of conducting regular proficiency tests to evaluate the level of preparedness of countries and of building a network of competent laboratories in terms of laboratory diagnosis to better face future emerging diseases in emergency conditions.

Application of the FTA elute card coupled with visual colorimetric loop-mediated isothermal amplification for the rapid diagnosis of Streptococcus agalactiae in farmed tilapia (Oreochromis niloticus)

A method combining the FTA Elute card and visual colorimetric loop-mediated isothermal amplification (FTA-e/LAMP) was tested to diagnose Streptococcus agalactiae infections in vitro and in vivo. FTA-e/LAMP consists of two main steps: first, the FTA card is used to extract DNA and then a colorimetric loop-mediated isothermal amplification (LAMP) reaction is carried out on the extracted DNA. In vitro sensitivity was 1.9 x 10²  CFU/mL, and regarding specificity, all nine S. agalactiae strains tested positive. All Streptococcus spp. tested negative, except for S. dysgalactiae, thereby indicating the need for another set of primers to distinguish this species from S. agalactiae. To diagnose S. agalactiae infections using FTA-e/LAMP in vivo, two experimental trials on juvenile Oreochromis niloticus infected with bovine or piscine strains were carried out. Sensitivity in symptomatic fish was 100%, and 50.7% of fish without signs were positive. All negative control fish tested negative (n = 28). No bacteria were detected after 16 days post-infection (dpi). Accuracy during the first week (1-7 dpi) was 89% and decreased to 44% thereafter (10-22 dpi). FTA-e/LAMP results suggest that this method is a promising tool for early and fast diagnosis of S. agalactiae on tilapia farms.

Wide Spread of bla CTX-M-9/mcr-9 IncHI2/ST1 Plasmids and CTX-M-9-Producing Escherichia coli and Enterobacter cloacae in Rescued Wild Animals

Wildlife has recently been pinpointed as one of the drivers of dissemination of genes conferring resistances to clinically important antimicrobials. The presence of both extended-spectrum beta-lactamase- (ESBL) and carbapenemase-encoding genes has notably been reported in wild birds, that can act as sentinels of antimicrobial resistance (AMR) contamination but also as long-distance spreaders in case of migratory birds. Here, 424 wild birds brought to a rescue center in France were sampled over a 6-month period. These birds encompassed 62 different sedentary or migratory species. A further 16 wild mammals present in the center were also investigated. No carbapenemase-producer was found, but we identified a surprisingly high proportion (24.1%) of ESBL-positive isolates. A total of 144 non-duplicate isolates were collected, including Escherichia coli (n = 88), Enterobacter cloacae (n = 51), and Citrobacter freundii (n = 5), of which 123 carried the bla_CTX–M–9 gene. PFGE, phylogroup, and MLST revealed the presence of a limited number of ESBL-positive clones circulating in these animals, all presenting multiple associated resistances. Next-generation sequencing on a subset of isolates, followed by Southern blot hybridization, showed the wide dissemination of an IncHI2/ST1 plasmid carrying the bla_CTX–M–9, bla_SHV–12 and mcr-9 genes. In all, our results undoubtedly reflect cross transmissions of ESC-resistance (ESC-R) Enterobacteriaceae within the rescue center – similarly to nosocomial spreads observed at hospital, rather than the true bacterial flora of birds. We also showed that the spread of ESC-R in this rescue center did not only rely on clonal but also on a highly successful plasmidic transmission. Since most animals are intended to get back to nature after a few days or weeks, this is obviously an issue with regard to ESBL dissemination in natural environments.

Long-lasting nosocomial persistence of chlorhexidine-resistant Serratia marcescens in a veterinary hospital

Healthcare-associated infections (HAIs) are often overlooked in veterinary medicine. Serratia marcescens isolates were recovered over a ten-year period from companion animals in a French veterinary hospital. The pets were sampled either for diagnostic purposes or to monitor colonization. A retrospective study showed that 32 S. marcescens isolates were identified as HAI cases and a further 22 cases were associated with colonization of the surgical site. Two S. marcescens lineages were responsible for two different outbreaks during the study period. Chlorhexidine solution (1%) used to impregnate gauze was found to be the source of the second S. marcescens outbreak and all isolates had high MIC values for chlorhexidine (MIC = 128 mg/L). This study reports, for the first time to our knowledge, the nosocomial spread of chlorhexidine-resistant S. marcescens in a veterinary setting and highlights consequences of the improper use of disinfectants.

Successful Application of the Gamma-Interferon Assay in a Bovine Tuberculosis Eradication Program: The French Bullfighting Herd Experience

In the French Camargue region, where bovine tuberculosis had been enzootic for several years in bullfighting cattle herds, the gamma-interferon (IFN) assay was used since 2003 in parallel with the intradermal test in order to increase overall disease detection sensitivity in infected herds. This study presents the results of a field-evaluation of the assay during a 10-year period (2004–2014) of disease control and surveillance program and explores the particular pattern of IFN assay results in bullfight herds in comparison to cattle from other regions of France. The low sensitivity [59.2% (50.6; 67.3)] of IFN assay using the tuberculin stimulation could be related to the poor gamma-IFN production from bullfight cattle blood cells which is significantly lower than in animals of conventional breeds. The characteristics of the assay were progressively adapted to the epidemiological situation and the desired strategic applications. Data analysis with a receiver operating characteristic curve based on a simple S/P value algorithm allowed for the determination of a new cutoff adapted for a global screening, giving a high specificity of 99.9% results and a high accuracy of the assay. Having regularly risen to above 5% since 2005, with a peak around 10% in 2010, the annual incidence dropped to under 1% in 2014. The positive predictive value relative to the bacteriological confirmation evolved during the years, from 33% in 2009 to 12% during the last screening period, a normal trend in a context of decreasing prevalence. The estimated rate of false-positive reactions during screening campaigns was 0.67%, confirming the high specificity of the test, measured in bTB negative herds, in this epidemiological context. The proportion of false-positive reactions decreased with the age and was higher in males than in females. Although these results indicate that the IFN assay is accurate in the field, it also emphasizes great differences between interferon quantities produced by bullfight cattle blood samples compared to those of classical bovine breeds, which underlines the necessity to adapt the algorithms and combinations of the assay according to local epidemiological contexts.

One particular Anaplasma phagocytophilum ecotype infects cattle in the Camargue, France

Background

Anaplasma phagocytophilum is a zoonotic tick-borne pathogen responsible for granulocytic anaplasmosis, a mild to a severe febrile disease that affects man and several animal species, including cows and horses. In Europe, I. ricinus is the only proven vector for this pathogen, but studies suggest that other tick genera and species could be involved in its transmission. Our objective was to assess the presence and genetic diversity of A. phagocytophilum in domestic animals and different tick species from the Camargue region, located in the south of France.

Methods

A total of 140 ticks and blood samples from 998 cattle and 337 horses were collected in Camargue and tested for the presence of A. phagocytophilum DNA by msp2 quantitative real-time PCR. Molecular typing with four markers was performed on positive samples.

Results

Anaplasma phagocytophilum DNA was detected in 6/993 (0.6%) cows, 1/20 (5%) Haemaphysalis punctata, 1/57 (1.75%) Rhipicephalus pusillus, and was absent in horses (0%). All cattle A. phagocytophilum presented a profile identical to an A. phagocytophilum variant previously detected in Dermacentor marginatus, Hyalomma marginatum, and Rhipicephalus spp. in Camargue.

Conclusions

Our results demonstrate that one particular A. phagocytophilum variant infects cattle in Camargue, where I. ricinus is supposed to be rare or even absent. Dermacentor marginatus, Rhipicephalus spp. and Hyalomma spp., and possibly other tick species could be involved in the transmission of this variant in this region.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2305-3) contains supplementary material, which is available to authorized users.

RESAMA: A Network for Monitoring Health and Husbandry Practices in Aquatic Research Facilities

Health monitoring is a crucial aspect of the management of any research animal house. RESAMA is a network strong of 60 academic and private partners acting in France since the end of 2012. The network aims to increase awareness of animal caretakers and researchers on health management issues in facilities holding aquatic model species (zebrafish, Xenopus, medaka, Mexican tetra). To do so, each partner research facility will be visited at least once. The visiting team is composed at least of one veterinarian and one zootechnician specialized in aquatic species. The visit results in a health-monitoring assessment of the facility, which includes a sampling for histo-pathological, bacteriological, and molecular pathogen detection. During the visit, rearing practices are also reviewed through an interview of animal caretakers. However, the present report essentially focuses on the health-monitoring aspect. The ultimate goal of the project is to provide a network-wide picture of health issues in aquatic facilities. Performed in parallel, the rearing practice assessment will ultimately help to establish rational relationship between handling practices and animal health in aquatic facilities. The study is still in progress. Here, we describe the results to be drawn from an analysis of the 23 facilities that had been visited so far. We sampled 720 fish and 127 amphibians and performed a little less than 1400 individual tests.

Evaluation of the SLOMYCO Sensititre(®) panel for testing the antimicrobial susceptibility of Mycobacterium marinum isolates

Background

The agar dilution method is currently considered as the reference method for Mycobacterium marinum drug susceptibility testing (DST). As it is time-consuming, alternative methods, such as the E-test, were evaluated for M.marinum DST, but without success. The SLOMYCO Sensititre^® panel, recently commercialized by TREK Diagnostic Systems (Cleveland, OH), can be used for DST in slow-growing mycobacteria and for antimicrobial agents recommended by the Clinical and Laboratory Standards Institute (CLSI) for M.marinum DST. The main goal of this work was to evaluate the SLOMYCO Sensititre^® panel method for DST in M.marinum isolates from human patients and fish relative to the reference agar dilution method.

Methods/Results

The reproducibility of the minimum inhibitory concentration (MIC) determination (±1 log₂ dilution) was very good for both the agar dilution method and SLOMYCO Sensititre^® panel (>90 % agreement). The percentage essential agreement between methods varied, depending on the drug: between 97 and 75 % for ciprofloxacin, moxifloxacin, linezolid, isoniazid, clarithromycin, amikacin, rifabutin and rifampin, 74 % for trimethoprim, 72 % for doxycycline, 70 % for sulfamethoxazole, 59 % for streptomycin, 33 % for ethambutol and only 2.2 % for ethionamide. When the agar dilution and SLOMYCO Sensititre^® panel results were converted into interpretive criteria, the category agreement was 100 % for amikacin, ciprofloxacin, clarithromycin, moxifloxacin, rifabutin, sulfamethoxazole and trimethoprim, 98 % for ethambutol and 96 % for rifampin and no agreement for doxycycline.

Conclusions

The SLOMYCO Sensititre^® panel method could provide a potential alternative to the reference agar dilution method, when DST in M.marinum is required, except for doxycycline.

First report of autochthonous non-vectorial canine leishmaniasis in New Caledonia, south-western Pacific: implications for new control measures and recommendations on importation of dogs

Background

Canine leishmaniasis (CanL), a parasitic zoonotic disease caused by Leishmania infantum and usually transmitted by phlebotomine sandflies, has rarely been reported in Pacific islands, which have been regarded until now as leishmaniasis-free territory. Here, we report the first autochthonous CanL case in New Caledonia (south-western Pacific) and the investigations carried out 1) to determine how infection was introduced into and transmitted among these dogs and 2) to assess the risks to animal and public health.

Methods

Extensive epidemiological and entomological investigations in and around the focus were carried out. Leishmaniasis infection was confirmed by histopathology, indirect fluorescent antibody test, real-time PCR, and culture. Parasite strain was typed by the isoenzymatic technique.

Results

The survey revealed close contacts between the autochthonous dog and two infected bitches imported from Spain, but failed to find any possible vector or disease spreading to other animals or humans. L. infantum zymodeme MON-1, the most frequent type in the Mediterranean basin, was identified. Although transplacental and venereal transmissions could not be excluded, the evidence was in favour of non-vectorial, direct dog-to-dog transmission.

Conclusions

This study corroborates the possibility of non-vectorial routes (transplacental, venereal, and direct dog-to-dog) of canine leishmaniasis transmission in New Caledonia and raises the debate of relevant test requirements and diagnostic sensitivity prior to importation of dogs in Leishmania-free regions. New leishmaniasis control measures and recommendations to avoid future CanL introduction on the island are discussed.

Bovine tuberculosis in Europe from the perspective of an officially tuberculosis free country: trade, surveillance and diagnostics

Switzerland has been officially free of bovine tuberculosis (OTF) since 1960. Since 1980 the control of bovine tuberculosis (bTB) has been reduced to passive abattoir surveillance. Isolated cases of bTB, partly due to reactivation of human Mycobacterium bovis infections with subsequent transmission to cattle, have been noticed in the last years. In Europe, the overall prevalence of bTB is slightly increasing. Both OTF and non-OTF countries report increases in the proportion of bTB positive cattle herds. Current bTB eradication and control programs in Europe are facing a range of challenges. Whole herd depopulation is becoming a less attractive option for economic reasons and due to animal welfare concerns. Live animal trade is increasing both at national and international levels. Regarding these tendencies and taking into account the chronicity of bTB infection, pre-movement testing is becoming increasingly important as a central tool for eradication and for protection against re-introduction of bTB. Pre-movement testing, however specifically focuses on the infection status in individuals, requiring a high level of diagnostic accuracy to correctly diagnose infected animals. Current screening tests for bTB, however, have been designed to meet demands as herd tests. This illustrates that the modification of existing and/or the development of new diagnostics for bTB might be needed. The tuberculin skin test (TST), the primary screening test for bTB may in certain situations have low sensitivity. The interferon gamma (IFN-γ) assay is accepted to be more sensitive compared to TST. Reduced specificity, however, especially in areas of low bTB prevalence raises concerns. New antigen combinations including Rv3615c, OmpATb and others have been shown to complement ESAT-6 and CFP-10 in the whole blood IFN-γ assay and resulted in improved sensitivity (compared to ESAT-6 and CFP-10) and specificity (compared to tuberculins). Lesion detection after slaughter represents a cost-effective procedure for passive surveillance of bTB, especially in areas of low prevalence or in regions free of bTB; however, its sensitivity is very low. This illustrates that trade is linked with a certain risk to re-introduce bTB in OTF regions or countries and that there may be delays in detecting a re-introduction of bTB. In conclusion, regarding the fact that some parameters linked with bTB programs are changing, the development of improved diagnostic tests with a high reliability for use as individual animal tests will be important for future eradication of bTB, in line with international commitment to high standard animal health programs.

Epidemiological study of canine trypanosomosis in an urban area of Ivory Coast

Following confirmed cases of trypanosomosis in military working dogs, a cross-sectional study was undertaken to evaluate the source of infection and determine the prevalence of canine infection with Trypanosoma congolense in the urban focus of Abidjan, Ivory Coast. Blood from 123 dogs were collected and subjected to PCR using specific primers for Trypanosoma congolense "forest type". In addition, an entomological study was conducted in an urban area near the forest surronding the military camp. The observed prevalence was 30.1% and PCR positivity to Trypanosoma congolense was not significantly associated with sex or age of animals. This study demonstrates the high contamination rate of dogs in enzootic zones, the potential risk of introduction of the disease in free animal populations and the ability of Glossina palpalis to adapt to urban areas and to transmit trypanosomosis in such areas. The factors leading to a possible emergence of canine trypanosomiasis in enzootic zones need further investigations.

[How to recognize POAD? The diagnosis of peripheral occlusive arterial disease in the physician's office]

Peripheral occlusive arterial disease (POAD) encompasses all stenotic and occlusive changes affecting the aorta and arteries supplying the extremities, and in 90% of the cases is due to atherosclerosis. In the majority of patients the lower extremities are involved, andonly every third patient has symptoms. Apart from its significance as an independent disease entity, POAD is also an important coincidence marker, in particular for coronary heart disease. For the diagnostic clarification of POAD, a stepped strategy is recommended, including clinical function testing, such as an exercise treadmill test. Doppler sonography and determination of the Doppler pressure index (ankle-brachial index) make possible a noninvasive accurate staging. Color-coded duplex sonography and imaging procedures provide further information, and are indispensable for establishing the indication for interventional measures.

Effects of dimerized lysozyme (KLP-602) on the cellular and humoral defence mechanisms in sheatfish (Silurus glanis): in vitro and in vivo study

This study examined the effects of the dimerized lysozyme (KLP-602) on the immunocompetence cell activity in sheatfish (Silurus glanis) and its influence in vivo on the non-specific defence mechanisms and protection against motile aeromonad septicaemia (MAS). The in vitro study showed that the lysozyme dimer (KLP-602), at concentrations between 5 and 50 micrograms/mL of medium significantly (P < 0.05) increased the respiratory burst activity and potential killing activity of pronephric macrophages, as well as the proliferative ability of pronephric lymphocytes stimulated by ConA and LPS. The in vivo study showed that injecting lysozyme dimer (Lydium-KLP) intraperitoneally at doses of 50 micrograms/kg bw stimulated cell-mediated and humoral-mediated imunity. On day 5, after application of Lydium-KLP in vivo, a statistically higher (P < 0.05) respiratory burst activity and potential killing activity of blood and pronephros phagocytes were observed. A higher proliferative ability of blood and pronephros lymphocytes stimulated by Concanavaline A (ConA) or lipopolysaccharide (LPS) was also observed. At the same time, the myeloperoxidase activity in the PMN cells and the lysozyme activity and total Ig levels in serum were significantly higher (P < 0.05), compared to the control group. A challenge test with Aeromonas hydrophila showed that dimerized lysozyme increased the protection against MAS. Dimerized lysozyme stimulates non-specific cellular and humoral mechanisms and protection against MAS in sheatfish.

The application of magnetization transfer to MR angiography with reduced total power

Magnetization transfer (MT) techniques have been shown to significantly reduce background soft-tissue signal in time-of-flight magnetic resonance angiography. To achieve sufficient suppression, radio frequency (RF) pulses with tip angles on the order of 1000 degrees are typically used, resulting in significant RF power deposition in the patient. Although these power deposition levels do not exceed the FDA guidelines, they are significantly higher than those used in typical imaging techniques. The use of these same magnetization transfer pulses in applications at field strengths higher than 1.5 T will require MT power levels which exceed FDA safety standards. This report demonstrates that the total power deposition required to achieve background tissue suppression can be significantly reduced by the application of the saturation pulses only during the phase-encoding steps corresponding to the central portion of "k space." This technique allows equivalent soft tissue suppression with approximately 10% of the energy deposition of conventional magnetization transfer techniques.