Is raw milk still vehicle for transmitting listeria species to pregnant Women ?

Abstract EN

-Numerous reports have been published about the occurrence of Listeria spp.

in different food sources including milk of different dairy species.

A total of 250 milk samples including; cows (150), buffaloes (50) and sheep (50) were collected from some private farms of dairy animals and retailers.

At the same time, 50 aborted women attending Al Shatbi Hospital, Alexandria were investigated for isolation of Listeria species from whole blood samples and vaginal swabs.

It was found that the rate of isolation of Listeria spp.

from milk samples was 7.33, 8 and 12% in the examined samples of cattle, buffaloes and sheep, respectively with significant association between the rates of isolation.

Identification of Listeria spp.

isolated from milk samples clarified the presence of L.

monocytogenes (2.4%), L.

ivanovii (2%), L.

innocua (1.2%) and L.

grayi (2.8%).

Concerning aborted women, it was found that Listeria spp.

were isolated from only 2 out of 50 vaginal swabs (4%) while we failed to isolate Listeria spp.

from blood samples.

Moreover, the 2 isolates were identified as L.

monocytogenes.

Statistical analysis showed non-significant association between the manners of milk consumption and the rate of isolation of L.

monocytogenes from aborted women where positive cases informed that they consumed milk in regular manner.

Also, statistical analysis showed non-significant association between presence of direct animal contact and the rate of isolation of L.

monocytogenes from aborted women where one positive case had animal contact and the other had no animal contact.

Finally, multiplex PCR was employed for detection of hylA and actA virulence genes for characterization of L.

monocytogenes isolated from milk and aborted women.

Based on the obtained results in the current study, it was clear that milk was considered to be potential vehicle for Listeria spp.

that might constitute a zoonotic risk for pregnant women.

Although the rate of isolation of listeria from aborted women was relatively low, the zoonotic hazard must not be neglected and further future studies should be carried out to highlight the zoonotic importance.

In addition, it was advisable to thorough heat treating of milk before consumption and veterinarians should do their efforts in controlling zoonotic diseases by encouraging prevention.