Screening for methicillin-resistant Staphylococcus aureus in clinical swabs using a high-throughput real-time PCR-based method.

The presence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals and the community is a serious problem. Accordingly, a comprehensive plan has been implemented in the County of Vejle, Denmark, to identify colonised and/or infected individuals and to control the spread of MRSA. Since 2005, all patients and healthcare personnel have been screened for MRSA colonisation, involving analysis of 300-400 samples daily. To deal with this number of samples, a PCR-based method customised for high-throughput analysis and a system for fast reporting of MRSA carrier status were developed. Swab samples were incubated overnight in a selective tryptone soya broth and were analysed by PCR the following day. Using this strategy, non-colonised individuals were identified within 24 h, while MRSA-positive samples were analysed further by traditional microbiological methods to determine the resistance pattern. This is a cost-effective approach, as the greatest expense in hospitals involves the isolation of patients of unknown MRSA status. The method was evaluated by testing 2194 clinical samples, with a sensitivity and specificity of 100% and 94%, respectively. The analytical sensitivity was 97%, with 161 of 166 different MRSA strains and isolates generating positive results according to PCR analysis. Using four control strains, the inter-assay variation was revealed to be a maximum of 2.6%, indicating good reproducibility.

In vivo assessment of breast muscle, abdominal fat and total fat volume in meat-type chickens by magnetic resonance imaging.

Measurements were performed on commercial broiler chickens by magnetic resonance imaging (MRI) tomography. A total of 72 chickens were scanned at the age of 6, 7, 8, 10, 16 and 20 weeks. MRI scans based on spin echo sequence were taken in the three orthogonal planes. The volume of the pectoral muscles increased from 259 cm3 to 1035 cm3 in males and from 250 cm3 to 875 cm3 in females between 6 and 20 weeks of age. Abdominal fat volume increased from 18.9 cm3 to 153.2 cm3 in males and from 19.3 cm3 to 267.0 cm3 in females between 7 and 20 weeks of age. Total body fat volume increased from 129 cm3 to 557 cm3 in males and from 171 cm3 to 1321 cm3 in females between 6 and 20 weeks of age. The correlation coefficients between the total volume of fat pixels and the amount of abdominal fat determined in the coronal plane by MRI were 0.85 and 0.95 in the male and female sex, respectively. Changes found in the pectoral muscles (mm. pectorales) as well as in total and abdominal fat volume were in close agreement with dissection data obtained at the slaughterhouse and with laboratory data based on the measurement of total body chemical composition in both sexes. This MRI method can be a good complement to computed tomography (CT) scanning in the transversal plane.