One Health surveillance-A cross-sectoral detection, characterization, and notification of foodborne pathogens.

Introduction: Several Proficiency Test (PT) or External Quality Assessment (EQA) schemes are currently available for assessing the ability of laboratories to detect and characterize enteropathogenic bacteria, but they are usually targeting one sector, covering either public health, food safety or animal health. In addition to sector-specific PTs/EQAs for detection, cross-sectoral panels would be useful for assessment of the capacity to detect and characterize foodborne pathogens in a One Health (OH) perspective and further improving food safety and interpretation of cross-sectoral surveillance data. The aims of the study were to assess the cross-sectoral capability of European public health, animal health and food safety laboratories to detect, characterize and notify findings of the foodborne pathogens Campylobacter spp., Salmonella spp. and Yersinia enterocolitica, and to develop recommendations for future cross-sectoral PTs and EQAs within OH. The PT/EQA scheme developed within this study consisted of a test panel of five samples, designed to represent a theoretical outbreak scenario. Methods: A total of 15 laboratories from animal health, public health and food safety sectors were enrolled in eight countries: Denmark, France, Italy, the Netherlands, Poland, Spain, Sweden, and the United Kingdom. The laboratories analyzed the samples according to the methods used in the laboratory and reported the target organisms at species level, and if applicable, serovar for Salmonella and bioserotype for Yersinia. Results: All 15 laboratories analyzed the samples for Salmonella, 13 for Campylobacter and 11 for Yersinia. Analytical errors were predominately false negative results. One sample (S. Stockholm and Y. enterocolitica O:3/BT4) with lower concentrations of target organisms was especially challenging, resulting in six out of seven false negative results. These findings were associated with laboratories using smaller sample sizes and not using enrichment methods. Detection of Salmonella was most commonly mandatory to notify within the three sectors in the eight countries participating in the pilot whereas findings of Campylobacter and Y. enterocolitica were notifiable from human samples, but less commonly from animal and food samples. Discussion: The results of the pilot PT/EQA conducted in this study confirmed the possibility to apply a cross-sectoral approach for assessment of the joint OH capacity to detect and characterize foodborne pathogens.

Alternative vanHAX promoters and increased vanA-plasmid copy number resurrect silenced glycopeptide resistance in Enterococcus faecium.

BACKGROUND: Vancomycin variable enterococci (VVE) are van-positive isolates with a susceptible phenotype that can convert to a resistant phenotype during vancomycin selection. OBJECTIVES: To describe a vancomycin-susceptible vanA-PCR positive ST203 VVE Enterococcus faecium isolate (VVESwe-S) from a liver transplantation patient in Sweden which reverted to resistant (VVESwe-R) during in vitro vancomycin exposure. METHODS: WGS analysis revealed the genetic differences between the isolates. Expression of the van-operon was investigated by qPCR. Fitness and stability of the revertant were investigated by growth measurements, competition and serial transfer. RESULTS: The VVESwe-R isolate gained high-level vancomycin (MIC >256 mg/L) and teicoplanin resistance (MIC = 8 mg/L). VVESwe-S has a 5'-truncated vanR activator sequence and the VVESwe-R has in addition acquired a 44 bp deletion upstream of vanHAX in a region containing alternative putative constitutive promoters. In VVESwe-R the vanHAX-operon is constitutively expressed at a level comparable to the non-induced prototype E. faecium BM4147 strain. The vanHAX operon of VVESwe is located on an Inc18-like plasmid, which has a 3-4-fold higher copy number in VVESwe-R compared with VVESwe-S. Resistance has a low fitness cost and the vancomycin MIC of VVESwe-R decreased during in vitro serial culture without selection. The reduction in MIC was associated with a decreased vanA-plasmid copy number. CONCLUSIONS: Our data support a mechanism by which vancomycin-susceptible VVE strains may revert to a resistant phenotype through the use of an alternative, constitutive, vanR-activator-independent promoter and a vanA-plasmid copy number increase.

Clinical and bacteriological effects of pivmecillinam for ESBL-producing Escherichia coli or Klebsiella pneumoniae in urinary tract infections.

OBJECTIVES: The prevalence of urinary tract infections (UTIs) caused by extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae is increasing and the therapeutic options are limited, especially in primary care. Recent indications have suggested pivmecillinam to be a suitable option. Here, we evaluated the clinical and bacteriological effects of pivmecillinam in UTIs caused by ESBL-producing Enterobacteriaceae. METHODS: We carried out a prospective follow-up of 39 patients diagnosed with UTI caused by ESBL-producing Enterobacteriaceae, initiated on pivmecillinam. The patients were from general practice (n = 29) or admitted to hospitals (n = 10) in the Copenhagen area, Denmark (n = 30) or Halland, Sweden (n = 9). Both patients and physicians were asked to complete a questionnaire on the pretreatment signs and symptoms. Patients were asked to send in two more urine samples for culture examination, together with questionnaires for clinical effect, 2-6 and 10-20 days, respectively, after end of treatment. RESULTS: Of the 39 patients included, 30 received a treatment regimen of 400 mg of pivmecillinam three times a day and 9 received 200 mg three times a day. All isolates were susceptible to mecillinam. The bacteriological cure rate was 79% (31/39); 80% (24/30) and 78% (7/9) for 400 and 200 mg three times a day, respectively. Relapse, i.e. ESBL-producing bacteria in the second control urine after previous bacteriological cure, was seen in five patients. Clinical cure was evaluable in 19 patients; 16 had a clinical effect (84%). CONCLUSIONS: Pivmecillinam was proven bacteriologically and clinically effective for treatment of lower UTIs caused by ESBL-producing Enterobacteriaceae.