Assessment of the aerobic faecal microflora in mink (Mustela vison Schreiber) with emphasis on Escherichia coli and Staphylococcus intermedius

The present study was undertaken to investigate the culturable aerobic faecal microflora of mink from newborn until adulthood with emphasis on the potential pathogens Escherichia coli and beta-haemolytic coagulase positive staphylococci. Rectal swabs were taken from 10 healthy dams and their offspring on seven mink farms throughout the production season and a semi-quantitative enumeration of total E. coli and haemolytic E. coli, beta-haemolytic streptococci, beta-haemolytic coagulase positive staphylococci, total lactic acid bacteria, and enterococci was carried out in all samples using selective and non-selective media. Aerobic bacteria were cultured from close to 100% of the samples throughout the survey. Prevalence of E. coli isolates varied between 70 and 90% of the samples throughout the survey with a small decline at the end of the study period. The highest bacterial counts were found among recently weaned kits or kits in the early growth period (P <0.0012). Lactic acid bacteria and enterococci were isolated from more than 90% of all samples, while β-haemolytic staphylococci were isolated from 20 to 70% of the samples. While β-haemolytic staphylococci were dominant from birth and during the nursing period, counts of staphylococci gradually decreased during the nursing period and were outnumbered by E. coli during the growth season.