Coxiella burnetii DNA, but not viable bacteria, in dairy products in France

Am J Trop Med Hyg. 2013 Apr;88(4):765-9. doi: 10.4269/ajtmh.12-0212. Epub 2013 Feb 4.

Abstract

Transmission by the oral route of Coxiella burnetii is controversial. Our objective was to evaluate dairy products in the transmission of Q fever. Pasteurized, unpasteurized, and thermized dairy products were tested for C. burnetii by using a quantitative polymerase chain reaction specific for IS1111 and IS30A spacers, culturing in human embryonic lung fibroblasts cells, and inoculation into BALB/c mice. We tested 201 products and C. burnetii was identified in 64%. Cow milk origin products were more frequently positive than goat or ewe products (P = 0.006 and P = 0.0001, respectively), and industrial food was more frequently positive than artisanal food (P < 0.0001). Food made from unpasteurized milk contained higher bacteria concentrations than food made from pasteurized milk (P = 0.02). All cultures were negative and mice did not show signs of illness. Farm animals are highly infected in France but consumption of cheese and yogurt does not seem to pose a public health risk for transmission of Q fever.

MeSH terms

  • Animals
  • Bacterial Load
  • Cattle / microbiology
  • Cells, Cultured
  • Coxiella burnetii / genetics
  • Coxiella burnetii / isolation & purification*
  • DNA, Bacterial / isolation & purification*
  • Dairy Products / microbiology*
  • Disease Reservoirs / microbiology
  • Fibroblasts / microbiology
  • Food Microbiology / methods
  • France
  • Goats / microbiology
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Microbial Viability*
  • Pasteurization
  • Polymerase Chain Reaction
  • Public Health
  • Q Fever / transmission*
  • Sheep / microbiology

Substances

  • DNA, Bacterial