CTX-M-producing Escherichia coli in pigs from a Czech farm during production cycle.

We evaluated the prevalence and epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates in pigs during production cycle on a Czech farm with the history of previous use of ceftiofur. ESBL-producing E. coli isolates were obtained from rectal swabs from pigs of different age groups (suckling piglets, weaned piglets, growers and sows). Collected samples were directly cultivated on MacConkey agar with cefotaxime (2 mg l-1 ), whereas intestinal swabs of slaughtered pigs and surface swabs from pig carcasses were also pre-enriched in buffered peptone water without antimicrobials before the cultivation. Clonal relationship of selected isolates was determined by XbaI pulse-field gel electrophoresis and multi-locus sequence typing. The transferability of plasmids carrying blaCTX-M genes was tested by conjugation experiments. From all examined samples, 141 (43·7%, n = 323) were positive for ESBL-producing E. coli. All ESBL-producing isolates showed resistance to multiple antimicrobials and were positive for blaCTX-M genes. The blaCTX-M-1 was carried by conjugative IncN/ST1 plasmids (c. 40-45 kb) while the blaCTX-M-15 was located on conjugative F plasmids with F:18:A5:B1 formula (c. 165 kb). This study demonstrated the persistence of CTX-M-positive E. coli isolates 2 months after banner of ceftiofur usage and indicated possible risk of transmission of these isolates to humans via the food chain.

Investigation of genetic diversity and polyandry of Leptinotarsa decemlineata using X-linked microsatellite markers.

A panel of X-linked microsatellite markers was newly designed using the data from a previous sequencing project available in NCBI and used for a study of the Colorado potato beetle (CPB, Leptinotarsa decemlineata) X-haplotype variability. The analysis of scaffolds 49 and 61 (newly identified as fragments of CPB chromosome X) found ten high-quality markers, which were arranged in two PCR multiplexes and evaluated in both 420 CPB adults, collected from 14 localities of Czechia and Slovakia, and 866 larvae from five single-female families from two more Czech localities. Length polymorphisms found in 6 loci have predicted 192 potential X-haplotypes, however, only 36 combinations were detected in the adult males (N = 189), and seven additional ones in the larvae. The X-haplotypes were also generally unevenly distributed; five of the most frequent haplotypes were detected in 55% of males, 19 repeating up to ten-times in 38.7% of males and the remained 12 occurred uniquely in 6.3% of males. Bulk analysis of X-haplotypes dissimilarity indicated seven haplotype groups diversified by mutations and recombinations. Two haplotypes showed a distinctive regional distribution, which indicates an east-west disruption of CPB migration probably caused by different environments of localities in the South Bohemia region and Vysocina region. On the contrary, the results indicate a south-north migration corridor alongside the Vltava River. In the single-female families, from 6 to 13 distinct paternal haplotypes were detected, which proved and quantified a frequented polyandry in CPB.