We report the spread of a clone of multidrug-resistant (MDR), ESBL-producing (bla CTX-M-1) Salmonella enterica subsp. enterica serovar Infantis, in the Italian broiler chicken industry and along the food-chain. This was first detected in Italy in 2011 and led to human infection in Italy in 2013–2014.A set (n = 49) of extended-spectrum cephalosporin (ESC)-resistant (R) isolates of S. Infantis (2011–2014) from humans, food-producing animals and meat thereof, were studied along with a selected set of earlier and more recent ESC-susceptible (ESC-S) isolates (n = 42, 2001–2014). They were characterized by macrorestriction-PFGE analysis and genetic environment of ESC-resistance. Isolates representative of PFGE-patterns and origin were submitted to Whole Genome Sequencing. The emerging ESC-R clone, detected mainly from broiler chickens, broiler meat and humans, showed a minimum pattern of clinical resistance to cefotaxime, tetracycline, sulfonamides, and trimethoprim, beside ciprofloxacin microbiological resistance (MIC 0.25 mg/L). All isolates of this clone harbored a conjugative megaplasmid (~ 280–320 Kb), similar to that described in ESC-susceptible S. Infantis in Israel (pESI-like) in 2014. This megaplasmid carried the ESBL gene bla CTX-M-1, and additional genes [tet(A), sul1, dfrA1 and dfrA14] mediating cefotaxime, tetracycline, sulfonamide, and trimethoprim resistance. It also contained genes conferring enhanced colonization capability, virulence (fimbriae, yersiniabactin), resistance and fitness (qacE1, mer) in the intensive-farming environment. This emerging clone of S. Infantis has been causing infections in humans, most likely through the broiler industry. Since S. Infantis is among major serovars causing human infections in Europe and is an emerging non-typhoidal Salmonella globally, further spread of this lineage in primary productions deserves quick and thorough risk-management strategies.

This study investigated two foodborne outbreaks of gastroenteritis that occurred 10 days apart among individuals who had meals at the restaurant of a farm holiday resort. Mild gastrointestinal symptoms were reported and none of the patients needed hospitalization. Mean incubation times were 45 and 33 h, and the overall attack rates were 43.5 and 58.3 %, respectively. Stool sample examination was negative for common enteric pathogens in both outbreaks. Specimens from 13 people involved in the second outbreak and 3 restaurant staff were examined for diarrhoeagenic Escherichia coli. An enteroaggregative E. coli (EAEC) strain of serotype O92 : H33 was isolated from six participants and one member of staff. In particular, the EAEC strain was isolated from five of the six cases of diarrhoea examined. The strain showed an aggregative pattern of adherence to HEp-2 cells, did not produce a biofilm and possessed the virulence-related genes aat, aggR, aap and set1A, but not the astA gene. A retrospective cohort study indicated a pecorino cheese made with unpasteurized sheep milk as the possible source (P,0.001). Samples of the cheese had E. coli counts higher than 10 6 c.f.u. g "1 , but the outbreak EAEC strain was not isolated. This report confirms that EAEC infections are probably underdiagnosed because of the limited availability of laboratories capable of identifying this group of pathogenic E. coli. INTRODUCTIONEnteroaggregative Escherichia coli (EAEC) are diarrhoeagenic E. coli characterized by the ability to adhere to HEp-2 cells in a characteristic 'stacked-brick' pattern (Nataro & Kaper, 1998). This property is usually due to the presence of aggregative adherence fimbriae, whose expression is positively controlled by the aggR gene, located on a large plasmid termed pAA (Nataro, 2005). EAEC infections are usually associated with watery diarrhoea, which is often persistent (Nataro & Kaper, 1998). Illness results from a complex interaction between pathogen and host, which implicates the initial adherence of the bacteria to the epithelium of terminal ileum and colon, in the characteristic aggregative pattern, followed by damage and a subsequent inflammatory response of the intestinal mucosa (Nataro, 2005;Huang et al., 2006).EAEC are a major cause of protracted diarrhoea in children in developing countries (Nataro & Kaper, 1998;Huang et al., 2006), where they are also linked to diarrhoeal illness of travellers and human immunodeficiency virus-positive patients (Huang et al., 2006). However, they have also been found to be associated with diarrhoea in industrialized countries (Tompkins et al., 1999;Weintraub, 2007). EAEC belong to a wide range of serotypes (Wilson et al., 2001) and are considered as emerging pathogens, characterized by a varied and complex epidemiology (Huang et al., 2006). Cases of EAEC infection are reported to be sporadic, but some outbreaks, involving both children and adults, have been described. The sources of infection have rarely been identified in these episodes. In France, an outbreak due to a...

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Salmonellosis is the second most commonly reported gastrointestinal infection in humans after campylobacteriosis, and an important cause of foodborne outbreaks in the EU/EEA. The vast majority (72.4%) of the salmonellosis foodborne outbreaks reported in EU in 2019 were caused by Salmonella Enteritidis, even if their total number due to this serovar decreased. In spring 2020, a foodborne outbreak of S. Enteritidis occurred in the Marche region (Central Italy), involving 85 people. The common exposure source was a cheese, pecorino “primo sale”, produced with raw sheep milk. The cheese batches were produced by two local dairies, with a livestock production facility, also including a sheep farm, being part of one dairy. Bacteriological analysis of samples collected allowed the detection of S. Enteritidis in animal faeces, environmental samples, raw-milk bulk tanks and milk taken from single animals. These data confirm that, despite the scarce scientific evidence, S. Enteritidis can infect sheep and be shed into the animals’ milk. Hence, this is a real risk for public health when unpasteurized milk is used in production of such cheese. The present paper describes the results of the investigations conducted to clarify this outbreak.

The study summarises the results obtained over the period 2002-2013 by the Italian IT-Enter-Vet network, aimed at collecting data on isolates from non-human sources. A total of 42,491 isolates were reported with a progressive decrease over the years. Typhimurium was the most frequent serovar up to 2011, but then, it was overtaken by 4,[5],12,:i:-, Derby Livingstone and Enteritidis alternated as the third most commonly isolated serovars. With regard to the sources of isolation, Typhimurium was distributed ubiquitously among the animal species. On the contrary, 4,[5],12,:i:- and Derby were strictly associated with pigs, whereas Livingstone Enteritidis and Infantis were clearly related to poultry. Intriguingly, when the frequency of serovar distribution along the food chain was considered, it was evident that Typhimurium and Derby tended to persist along the chain, as they were isolated even more frequently from foods than from animals. A similar distribution was found for Enteritidis and Hadar. Despite limitations related to non-mandatory participation of laboratories in the network, the data presented are valuable to obtain a picture of the evolution of from non-human sources over time in Italy.

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Salmonella enterica is a major epidemic cause of gastrointestinal infection worldwide. Although the animal host is believed to be the primary habitat of this specie, Salmonella is frequently isolated from water sources and it has been identified in marine environments. In this study the incidence of serotypes of Salmonella in the coastal water of the Italian region of Marche on the Adriatic Sea was evaluated. A total of 3985 samples of molluscan shellfish were analyzed during routine surveillance activity for a period of five years (2002-2007) and 0,95% of the samples were found contaminated with Salmonella. The most prevalent serotypes were Seftenberg (23.5%), Typhimurium (14,7%) and Enteritidis (11.8%) respectively. Pulsed-field electrophoresis and phage typing were used to determine possible genetic relationship (relatedness) between S. Enteritidis strains isolated from bivalve mollusc and those isolated from human cases, animals and foods in Region of Marche. Three isolates from mollusc shellfish, 7 from sporadic human infection and 4 from poultry farms were confirmed as phagetype PT2 and PFGE profile XB0002. These results suggest a molecular fingerprinting relationship among shellfish, human and animal isolates, which could be considered as preliminary evidence of human infections associated with poultry production industry