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Introduction: The aim of this study was to determine whether there is an association between Cryptosporidium infections in calves and immunological factors, as well as farm-related factors or the application of the anti-cryptosporidiosis drug Halofuginone. From January to June 2010, 63 cow-calf-pairs from 20 different farms near Zürich, Switzerland have been investigated. Each cowcalf- pair was visited three times within the first 6 weeks of life to collect data of the farm and animals, as well as blood, faecal, colostral and milk samples. An ELISA using sporozoite antigen was developed for the specific detection of anti-Cryptosporidium-IgG in blood- and colostral serum. The IgG concentration in the bloodand colostral serum was determined using radial immuno diffusion test (RID). White blood cell isolation and differential blood cell counts and California Mastitis Test were performed. Bacteriological studies on quarter-milk-samples were carried out. Cryptosporidium oocysts were diagnosed with the modified Ziehl-Neelsen staining, other protozoa with the SAFC method and Eimeria oocysts and helminth eggs were diagnosed with the combined sedimentation/floatation test. ELISAs were performed for the detection of rota- and coronavirus, E. coli F5 and Cryptosporidium spp. in bovine feces (bio-X Diagnostics®, Belgium). The highest prevalence of Cryptosporidium oocysts was 54.0% and found 7 to 20 days post natum, whereas 47.1% were suffering from diarrhea. The transfer of total IgG with the colostrum and the humoral immunity of the calf could not prevent any infection with Cryptosporidium, but the severity of the diarrhea symptoms decreased with increasing total IgG concentrations. Calves housed in open sheds showed significantly more often diarrhea, i. e. they shed more Cryptosporidium oocysts during the first 4 days and 7 to 20 days post natum, respectively. Halofuginone (Halocur®) is approved for prophylaxis against cryptosporidiosis, but it showed no effect on the excretion of Cryptosporidium oocysts in the present study.

Various instruments and utensils used during milking as well as teat dip solutions were examined for contamination with coagulase-negative staphylococci (CNS). The goal of this study was to investigate the relationship between contaminated fomites and udder infection in dairy cows. A total of 344 cows from ten dairy farms with the highest rate of clinical mastitis among the farms serviced by the Ambulatory Clinic of the University of Zurich were included in the study. Each farm was visited five times. All lactating cows, with the exception of those undergoing antibiotic treatment, were examined immediately before milking using the California Mastitis Test (CMT). A milk sample was collected from positive quarters. Items used to clean the udder, which included wood wool, paper towels and disinfecting towels as well as the milker's hands and the teat dip cup were swabbed for bacteriological examination. Water samples, samples of teat dip and cleaning solutions were also collected and cultured. Our results demonstrate that cleaning and disinfecting solutions have the potential to transmit udder pathogens and cause clinical mastitis. The most common CNS isolated from quarter samples were S. saprophyticus, S. sciuri and S. chromogenes, and the most common CNS isolated from utensils, cleaning and disinfecting solutions were S. fleuretii, S. vitulus, S. equorum, S. sciuri, S. haemolyticus, S. succinus and S. saprophyticus.

Staphylococcus aureus and coagulase negative staphylococci (CNS) were isolated from ovine and caprine mastitis milk samples originating from more than 40 Swiss farms. CNS dominated as causal microorganisms of mastitis in small ruminants. By restriction fragment length polymorphism (RFLP) analysis of the groEL gene and sequencing of 16S rDNA, various CNS species were identified, albeit certain of them predominated. For susceptibility testing of mastitis pathogens to selected antibiotics, minimal inhibitory concentrations were determined. Of the 67 S. aureus and 208 CNS strains, 31.3 % and 8.2 % were resistant to penicillin, 29.9 % and 1.0 % to ampicillin, 1.5 % and 10.6 % to erythromycin, and 3.0 % and 7.7 % to tetracycline, respectively. Moreover, 10 CNS strains (4.8 %) were resistant to oxacillin and one CNS strain to sulfamethoxazole/trimethoprim. The results obtained describe for the first time the resistance situation of mastitis pathogens from sheep and goats in Switzerland. However, accompanying and preventing measures are also of importance in mastitis control of small ruminants.

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.