Factors associated with the occurrence of MRSA CC398 in herds of fattening pigs in Germany

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to investigate the prevalence of MRSA in herds of fattening pigs in different regions of Germany, and to determine factors associated with the occurrence of this pathogen. For this purpose pooled dust samples were collected, and a questionnaire covered information regarding herd characteristics and management practices. Samples were pre-enriched in high-salt medium followed by selective enrichment containing cefoxitin/aztreonam, and culturing. Presumptive colonies were confirmed by multiplex-PCR targeting <it>nuc-</it>, <it>mecA</it>- and 16S rRNA-genes. Isolates were s<it>pa- </it>and SCC<it>mec</it>-, and in selected cases, multilocus sequence-typed. Susceptibilities to 13 antimicrobials were determined by broth microdilution. Statistical analysis was carried out using backward stepwise logistic regression to calculate odds ratios with the MRSA test result as the outcome and herd characteristics as categorical covariates.</p> <p>Results</p> <p>Overall, 152 of 290 (52%) fattening pig farms tested positive for MRSA. The prevalence in the east, north- and south-west of Germany ranged from 39 to 59%.</p> <p>t011 (66%) and t034 (23%) were the most commonly identified s<it>pa</it>-types, and 85% of isolates carried SCC<it>mec </it>Type V. Identified <it>spa</it>-types were all associated with clonal complex CC398. Susceptibility testing revealed that all isolates were resistant to tetracycline. High resistance rates were also found for sulfamethoxazole/trimethoprim (40%), and quinupristin/dalfopristin (32%). In addition, 83% of strains displayed multidrug resistant (> 3 substance classes) phenotypes.</p> <p>Logistic regression revealed herd size (large farms OR: 5.4; CI: 2.7-11.2; p < 0.05), and production type (wean-to-finish OR: 4.0; CI: 1.6-10.4; p < 0.05) as risk factors associated with a positive MRSA finding in fattening pig operations.</p> <p>Conclusions</p> <p>MRSA CC398 is widely distributed among herds of fattening pigs in Germany. Farm management plays a crucial role in the dissemination of MRSA with herd size, and production type representing potential major indicators.</p

Decontamination of High-risk Animal and Zoonotic Pathogens

Program obilježavanja Noći muzeja 31. siječnja 2020. na Sveučilištu u Zagrebu