Strongyle faecal egg counts in Swiss horses: A retrospective analysis after the introduction of a selective treatment strategy

The standard parasite management of horses based on regular anthelmintic treatments, now practiced for decades has resulted in a worrying expansion of resistant helminth populations, which may considerably impair control on the farm level. The aim of the present study was to obtain a retrospective (year 2010 - 2016) nationwide analysis of faecal egg count (FEC) data from the Swiss adult horse population, related to horse age and geographic region. Thirteen labs provided a total of 16,387 FEC data of horses aged four to 39 years (average: 13.6 years). The annual number of performed FEC tests increased from 38 to 4,939 within the observation period. Independent of the annual sample size the yearly patterns of the FEC were very similar. Seventy-eight percent (n = 12,840) of the samples were negative and 90 % (n = 14,720) showed a FEC below 200 strongyle eggs per gram (EPG) of faeces. The annual mean strongyle FEC ranged between 60 and 88 EPG with a total mean of 75 EPG. Horses aged 4-7 years showed a significantly (p < 0.00001) higher mean FEC compared with the other age groups, differences were not significant among the older horses. Based on ZIP codes, samples were allocated by 70.0 %, 6.0 % and 0.2 % to the German-, French- and Italian-speaking regions of Switzerland, respectively. With 222 EPG the mean FEC in the French part of Switzerland was significantly higher (p < 0.05) than in the German-speaking region (60 EPG). Eggs of Parascaris spp., anoplocephalids and Strongyloides westeri were found in 0.36 %, 0.32 % and 0.01 % of the samples, respectively. Based on 3,813 questionnaire feedbacks from owners in 2017 covering a total of 12,689 horses, sixty-eight percent (n = 8,476) were dewormed without diagnosis, two percent (n = 240) were not dewormed at all, whereas for 30 % (n = 3,721) the selective anthelmintic treatment (SAT) concept was applied. The SAT implementation rate differed significantly (p < 0.0005) between regions, with 33 %, 20 % and 25 % for the German-, French- and Italian-speaking areas, respectively. The rate of horses spending 16-24 h on pasture per day was significantly higher in the French-speaking region compared to the German-speaking part of Switzerland (p < 0.0001). In addition, pasture hygiene was practiced at a significantly lower rate in the French-speaking part compared to the German- and Italian-speaking regions (both p < 0.0001). Overall, the shift towards the SAT-concept represents a very promising development with respect to mitigating the further spread of anthelmintic resistance.

Aktuelle Daten zur Antibiotikaresistenz der wichtigsten bovinen Mastitiserreger in der Schweiz

100 strains of Staphylococcus aureus (S. aureus), 100 strains of coagulase-negative staphylococci (CNS), 100 strains of Streptococcus spp. and 100 strains of Escherichia coli (E. coli), isolated from bovine mastitis milk samples between November 2002 and April 2003, were tested for their sensitivity to various antibiotics by means of the agar diffusion method. The antibiotics were chosen on the basis of their licenses for intramammary application in Switzerland (www.vetpharm.unizh.ch). 91% of the S. aureus strains were sensitive to all the antibiotics tested. Only 9% of the strains were resistant to Penicillin G and 7% to Ampicillin. 53% of the CNS strains were sensitive to all the antibiotics tested. 31% exhibited resistance to Penicillin G, 26% to Ampicillin, 16% to Cloxacillin and 14% to Lincomycin. 30% of the Streptococcus spp. strains were sensitive to all the antibiotics tested. 4% were resistant to Penicillin G, 4% to Amoxicillin/clavulanic acid, 1% to Cefoperazone, 2% to Cefquinome, 35% to Neomycin, 22% to Gentamicin, 61% to Kanamy-cin and 11% to Lincomycin. 43% of the strains showed multiple resistance. 79% of the E. coli strains were sensitive to all the antibiotics tested. 20% exhibited resistance to Ampicillin, 9% to Neomycin and 10% to Kanamycin. A comparison of the own results with data of other authors in Switzerland shows no important changes in the resistance situation during the last 20 years. With the exception of two strains (Streptococcus spp.), all tested isolates were sensible against Cefquinome.

Detection of eight Cryptosporidium genotypes in surface and waste waters in Europe

Cryptosporidia are important protozoan parasites of vertebrates, and a number of species and genotypes, with different host ranges, have been described. In this study a protocol was established for the detection and the genetic characterization of Cryptosporidium spp. isolated from various types of surface waters (rivers, creeks, lakes, sewage plant in- and outlets and swimming pools) from the area between Zurich (Switzerland) and Munich (Germany). Cryptosporidium oocysts were isolated by continuous-flow-centrifugation and immunomagnetic separation (IMS). A novel nested PCR combined with direct sequencing of the amplicon which spans a variable region of the 18S rRNA allowed characterization of species and genotypes. Cryptosporidium spp. were detected in 23 of the 68 water samples investigated. Almost half of these isolates represent species and genotypes known to be pathogenic to man, namely C. parvum 'bovine genotype' (from 6 samples) and C. parvum 'human genotype' (4). Furthermore, we identified C. muris 'genotype A' (3), C. muris 'genotype B' (6), C. baileyi (1) as well as 3 novel Cryptosporidium genotypes. Our results confirm the ubiquitous presence of Cryptosporidium oocysts in surface waters. The detection of a variety of species and genotypes stresses the importance that molecular characterization is indispensable before drawing conclusions of medical or epidemiological significance.