Behaviour of Escherichia coli O157:H7 during the manufacture and ripening of an Italian traditional raw goat milk cheese

Formagelle di capra is a raw goat cheese produced from whole chilled goat milk; traditional technology involving unpasteurised milk and indigenous lactic starter cultures is employed for its production in Italy. The purpose of this study was to assess the behavior of Escherichia coli O157:H7 during the manufacturing and ripening of this raw goat milk cheese. Raw milk was experimentally inoculated with E. coli O157:H7 in a laboratory scale plant and the count was monitored during production and 30 days of ripening required for this cheese. Results showed that E. coli O157:H7 count increased to more than 1.5 Log cfu g-1 during cheese production and remained constant until the end of ripening. The evidence that E. coli O157:H7 is able to survive during the manufacturing and ripening process suggests that the 30-day ripening period alone is insufficient to eliminate levels of viable E. coli O157:H7 in Formaggelle di capra cheese and that the presence of low numbers of E. coli O157:H7 in milk destined for the production of raw goat milk cheeses could represent a potential source of infection for humans and a threat for consumer

Identification of a major Listeria monocytogenes outbreak clone linked to soft cheese in Northern Italy - 2009-2011

Background: Molecular subtyping and enhanced surveillance in Lombardy region identified a cluster of possibly related listeriosis cases from 2006 to 2010. This cluster grouped 31 isolates that belonged to serotype 1/2a and Sequence Type 38 (ST38) as defined by Multilocus Sequence Typing (MLST). Methods: Our study expanded the previous investigation to include cases from 2011 to 2014 and used Multi-Virulence- Locus Sequence Typing (MVLST) on all ST38 isolates to better understand their epidemiology and possibly identify a common source outbreak. Results: Out of 306 L. monocytogenes clinical isolates collected, 43 (14.1%) belonged to ST38 with cases occurring in nine out of twelve Lombardy provinces. The ST38 isolates were split by MVLST into two Virulence Types (VTs): VT80 (n = 12) and VT104 (n = 31). VT104 cases were concentrated between 2009 and 2011 in two provinces, Bergamo and Milan. An epidemiologic investigation was performed and in one case, a matching VT104 isolate was retrieved from a soft cheese sample from a patient's refrigerator. Conclusions: Our findings revealed a major listeriosis outbreak in Northern Italy linked to soft cheese in 20092011, which went undetected by local health authorities. Our study shows that integrating subtyping methods with conventional epidemiology can help identify the source of L. monocytogenes outbreak clones

OCCURRENCE OF LISTERIA MONOCYTOGENES IN READY TO EAT FOOD SAMPLES COLLECTED BY LOMBARDY REGION HEALTH AUTHORITIES IN 2009-2010

The study provides data on the prevalence of Listeria monocytogenes in ready-to-eat food samples collected by Lombardy region health authorities and analyzed by Department of Food Microbiology, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna. From the total of 503 food samples analyzed, the pathogen was detected in 85 (16,9%). In particular it was highlighted in 8/152 (5,3%) meat products, in 5/245 (2%) dairy products and in 42/106 (39,6%) fishery products. Given the considerable public health implications, the study confirms that a well-planned program of listeriosis surveillance should be enforced to suitably estimate the burden of disease and to prevent foodborne outbreaks

Genomic characterization of porcine rotaviruses in Italy

A total of 23 rotavirus strains isolated from pigs were analyzed. Twenty strains had been isolated from diarrheic piglets from an outbreak that occurred in northern Italy in 1983. Three strains had been isolated in 1984 from swine herds located in distinct areas of northern Italy. All 23 strains were characterized as type G6P[5] by PCR. The isolation from piglets of rotaviruses displaying typical bovine G- and P-type specificities points out the high frequency of rotavirus transmission between cattle and pigs