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Abstract: In the present study, the prevalence of S. aureus in mammary gland quarters of dairy cows in Switzerland was estimated and a risk factor analysis was carried out. Dairy cows were selected by one-step-cluster sampling with stratification by herd size. Forty-seven of 50 randomly chosen farms participated in the study, resulting in 603 cows and 2388 quarter samples. Milk samples were collected in all herds on two occasions two weeks apart. In 6% of cows (95% CI: 2.7–9.3%) at least one milk sample was positive for S. aureus and from 2% (0.8–3.2%) of all quarters, S. aureus was cultured at least once. In four quarters a latent S. aureus infection (agent detected and somatic cell count (SCC) <100,000cell/ml) was diagnosed. Multivariable hierarchic logistical regression analysis yielded five significant risk factors for observing S. aureus in a milk sample: high SCC, a S. aureus-positive neighbouring quarter, a palpable induration in the quarter, and a wound, scar tissue or crush injury affecting the teat. The type of housing (P =0.1596) was also a factor that remained in the model. The mentioned risk factors must be considered during the evaluation of herds with S. aureus problems. The occurrence of latent S. aureus infections emphasises that not only quarters with a high SCC but all quarters of all cows must be cultured for control measures to be effective. [Copyright &y& Elsevier]

Based on a former study from our group, one subtype of Staphylococcus aureus was associated with high within-herd prevalence of mastitis, whereas the other subtypes were associated with a low prevalence (sporadic intramammary infection). To confirm this hypothesis, a prospective study was done in 29 Swiss dairy herds. In particular, milk samples were collected from 10 herds with Staph. aureus herd problems (cases) and compared with samples from 19 herds with only sporadic cases of with Staph. aureus intramammary infection (controls). The isolates were tested for their virulence gene pattern and genotyped by PCR amplification of the 16S-23S rRNA intergenic spacer. The patterns and genotypes were then associated and compared with epidemiological and clinical data. Confirming the hypothesis, one particular subtype (genotype B) was associated with high within-herd and within-cow prevalence of intramammary infection, whereas the other subtypes were associated with low within-herd prevalence and infected single quarters. The gene patterns and genotypes were highly related, demonstrating the genetic diversity of the genotypes. The somatic cell counts were clearly increased in herds with a genotype B problem compared with herds with infections of other genotypes. Based on the different clinical properties and treatment consequences associated with these different genotypes found in Switzerland, we recommend subtyping Staph. aureus in other countries to determine if this finding is universally applicable. [ABSTRACT FROM AUTHOR]

Purpose: The control of antibiotic resistance and nosocomial infections are major challenges for specialized burn centres. Early detection of those epidemic outbreaks is crucial to limit the human and financial burden. We hypothesize that data collected by antibiotic consumption medico-economic surveys could be used as warning signal to detect early nosocomial outbreaks., Methods: A retrospective analysis was conducted that included all burn patients staying >48h on the Lausanne BICU (Burn Intensive Care Unit) between January 2001 and October 2012 who received systemic therapeutic antibiotics. Infection episodes were characterized according to predefined criteria. Antibiotic consumption data, obtained from the quarterly surveillance of drug consumption surveys, were translated into defined daily doses (DDDs)., Results: In total, 297 out of 414 burn patients stayed >48h, giving a total of 7458 'burn-days'. We identified 610 infection episodes (burn wound [32.0%], respiratory [31.1%], and catheter [21.8%]), from 774 microorganisms. Pseudomonas aeruginosa (26.2%), Staphylococcus aureus (11.5%), and Candida albicans (7.0%) were the main pathogens. We observed three distinct outbreaks of P. aeruginosa infections in 2002-2003, 2006, and 2009-2011. These outbreaks correlated with an increase in the DDDs of anti-Pseudomonas antibiotics., Conclusions: Our data support a paradigm shift in the epidemiological surveillance of nosocomial P. aeruginosa epidemics in burn centres, using the rise in antibiotic consumption as an early trigger to initiate the molecular typing of P. aeruginosa strains and the reinforcement of standard infection control procedures., (Copyright © 2016. Published by Elsevier Ltd.)

Data from 59 farms with complaints of udder health problems and insufficient quality of delivered milk that had been assessed by the Swiss Bovine Health Service (BHS) between 1999 and 2004 were retrospectively analysed. Data evaluated included farm characteristics such as farm size, herd size, average milk yield, milking system and housing system, deficits of the milking equipment and the milking practices, and bacteriological results of milk samples from all cows in lactation. The average size of the farms assessed by the BHS was larger than the size of the were evaluated, 42 showed obvious failures which the farm managers could have noticed. Only 5 of the 57 milkers carried out their work according to the generally valid guidelines of the National Mastitis Council. More than 2 basic mistakes were observed in the milking practices of 36 milkers. In 51 farms, mixed infections with several problem bacteria (those present in at least 20 % of the tested cows on a farm) were found. Staphylococcus aureus proved to be the most common problem germ. As the bacteria responsible for the herd problem (the sole problem bacteria detectable on a particular farm) Staphylococcus aureus was detected in 4 farms. The current study revealed that education in the area of milking techniques and milking practices of farmers should be improved in order to reduce the incidence of udder health problems on herd level. Staphylococcus aureus is the most important problem bacteria involved in herds with udder health problems in Switzerland. Staphylococcus aureus might be used in practice as the indicator germ for early recognition of management problems in dairy farms.