Influence of porcine circovirus type 2 vaccination on the level of antimicrobial consumption on 65 Austrian pig farms.

The administration of antibiotics to farm animals is an important contemporary topic. Veterinarians, pig producers, politicians, retailers and consumers all have a vested interest in reducing antimicrobial use on farm, while ensuring adequate health and welfare of food-producing animals. Vaccination programmes may be used to reduce the overall level of clinical disease in a population, subsequently leading to a decline in antimicrobial use. In 2008, a vaccination programme against porcine circovirus type 2 (PCV-2) was initiated in Austria. In the retrospective observational study presented here, farm medication records (2008-2011) from 65 conventional pig farms were evaluated. As PCV-2 has been shown to lead to generalised immunosuppression, enabling secondary bacterial infections to occur, the authors hypothesised that PCV-2 vaccination would decrease antimicrobial consumption at farm level. Firstly, we focused on the annual antimicrobial consumption expressed as the number of administered animal daily doses per kg liveweight (nADDkg/kg/year). Secondly, a linear mixed effects model was applied to evaluate the influence of PCV-2 vaccination on the antimicrobial consumption at farm level. The interaction between farm type and PCV-2 vaccination was found to be a highly significant factor (P=0.0002) influencing antimicrobial use at farm level. The estimated impact of PCV-2 vaccination revealed a highly significant (P<0.001) decline in total antimicrobial drug use from 1.72 ADDkg/kg/year to 0.56 ADDkg/kg/year on finishing farms, whereas only a negligible decline was detectable on farrow-to-finish farms.

Direct PCR of indigenous and invasive mosquito species: a time- and cost-effective technique of mosquito barcoding.

Millions of people die each year as a result of pathogens transmitted by mosquitoes. However, the morphological identification of mosquito species can be difficult even for experts. The identification of morphologically indistinguishable species, such as members of the Anopheles maculipennis complex (Diptera: Culicidae), and possible hybrids, such as Culex pipiens pipiens/Culex pipiens molestus (Diptera: Culicidae), presents a major problem. In addition, the detection and discrimination of newly introduced species can be challenging, particularly to researchers without previous experience. Because of their medical importance, the clear identification of all relevant mosquito species is essential. Using the direct polymerase chain reaction (PCR) method described here, DNA amplification without prior DNA extraction is possible and thus species identification after sequencing can be achieved. Different amounts of tissue (leg, head; larvae or adult) as well as different storage conditions (dry, ethanol, -20 and -80 °C) and storage times were successfully applied and showed positive results after amplification and gel electrophoresis. Overall, 28 different indigenous and non-indigenous mosquito species were analysed using a gene fragment of the COX1 gene for species differentiation and identification by sequencing this 658-bp fragment. Compared with standard PCR, this method is time- and cost-effective and could thus improve existing surveillance and control programmes.