Genomic features and heat resistance profiles of Escherichia coli isolated from Brazilian beef.

AIMS: Characterize Escherichia coli and E. coli -producing (STEC) isolates from Brazilian beef to determine heat resistance and the presence of the transmissible locus of stress tolerance (tLST). METHODS AND RESULTS: Twenty-two STEC previously isolated from beef and characterized as STEC by PCR were subjected to different heat survival challenges (60°C and 71°C). Furthermore, the three tLST-positive isolates and one tLST-negative isolate by PCR were selected for WGS analysis. Phenotypic results indicated that 3/22 (13.64%) were heat resistant, 12/22 (54.54%) were moderately resistant, and 7/22 (31.82%) were sensitive to heat treatments. WGS analyses showed that three isolates with heat resistance showed tLST with up to 80% and 42% of similarity by BLAST analysis, with the major tLST genes being responsible for the homeostasis module. However, WGS showed the absence of stx genes associated with tLST-positive isolates, albeit with virulence and resistance genes found in extraintestinal pathogenic E. coli (ExPEC). CONCLUSION: Our findings demonstrate the presence of heat-resistant E. coli as well as confirm some tLST genes in E. coli isolated from Brazilian beef.

Development of a novel tetravalent peptide that absorbs subtilase cytotoxin by targeting the receptor-binding B-subunit.

Subtilase cytotoxin (SubAB) is a major virulence factor produced by eae-negative Shiga-toxigenic Escherichia coli (STEC) that can cause fatal systemic complications. SubAB binds to target cells through multivalent interactions between its B-subunit pentamer and receptor molecules such as glycoproteins with a terminal N-glycolylneuraminic acid (Neu5Gc). We screened randomized multivalent peptide libraries synthesized on a cellulose membrane and identified a series of tetravalent peptides that efficiently bind to the receptor-binding region of the SubAB B-subunit pentamer. These peptides competitively inhibited the binding of the B-subunit to a receptor-mimic molecule containing clustered Neu5Gc (Neu5Gc-polymer). We selected the peptide with the highest inhibitory efficacy, FFP-tet, and covalently bound it to beads to synthesize FFP-tet-beads, a highly clustered SubAB absorber that displayed potency to absorb SubAB cytotoxicity through direct binding to the toxin. The efficacy of FFP-tet-beads to absorb SubAB cytotoxicity in solution was similar to that of Neu5Gc-polymer, suggesting that FFP-tet-beads might be an effective therapeutic agent against complications arising from eae-negative STEC infection.

Optimization of Notification Criteria for Shiga Toxin-Producing Escherichia coli Surveillance, the Netherlands.

We describe the consequences of 2 major changes in notification criteria for Shiga toxin-producing Escherichia coli surveillance in the Netherlands. The change to reporting acute, more severe infections appears to be a good compromise between workload, redundancy, and public health relevance, provided isolates remain available for typing and sequencing.

EHEC O111:H8 strain and norovirus GII.4 Sydney [P16] causing an outbreak in a daycare center, Brazil, 2019.

BACKGROUND: This study describes the investigation of an outbreak of diarrhea, hemorrhagic colitis (HC), and hemolytic uremic syndrome (HUS) at a daycare center in southeastern Brazil, involving fourteen children, six staff members, six family members, and one nurse. All bacterial and viral pathogens detected were genetically characterized. RESULTS: Two isolates of a strain of enterohemorrhagic Escherichia coli (EHEC) serotype O111:H8 were recovered, one implicated in a case of HUS and the other in a case of uncomplicated diarrhea. These isolates had a clonal relationship of 94% and carried the stx2a and eae virulence genes and the OI-122 pathogenicity island. The EHEC strain was determined to be a single-locus variant of sequence type (ST) 327. EHEC isolates were resistant to ofloxacin, doxycycline, tetracycline, ampicillin, and trimethoprim-sulfamethoxazole and intermediately resistant to levofloxacin and ciprofloxacin. Rotavirus was not detected in any samples, and norovirus was detected in 46.7% (14/30) of the stool samples, three of which were from asymptomatic staff members. The noroviruses were classified as the recombinant GII.4 Sydney [P16] by gene sequencing. CONCLUSION: In this outbreak, it was possible to identify an uncommon stx2a + EHEC O111:H8 strain, and the most recent pandemic norovirus strain GII.4 Sydney [P16]. Our findings reinforce the need for surveillance and diagnosis of multiple enteric pathogens by public health authorities, especially during outbreaks.

Predicting Hemolytic Uremic Syndrome and Renal Replacement Therapy in Shiga Toxin-producing Escherichia coli-infected Children.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) infections are leading causes of pediatric acute renal failure. Identifying hemolytic uremic syndrome (HUS) risk factors is needed to guide care. METHODS: We conducted a multicenter, historical cohort study to identify features associated with development of HUS (primary outcome) and need for renal replacement therapy (RRT) (secondary outcome) in STEC-infected children without HUS at initial presentation. Children aged <18 years who submitted STEC-positive specimens between January 2011 and December 2015 at a participating study institution were eligible. RESULTS: Of 927 STEC-infected children, 41 (4.4%) had HUS at presentation; of the remaining 886, 126 (14.2%) developed HUS. Predictors (all shown as odds ratio [OR] with 95% confidence interval [CI]) of HUS included younger age (0.77 [.69-.85] per year), leukocyte count ≥13.0 × 103/µL (2.54 [1.42-4.54]), higher hematocrit (1.83 [1.21-2.77] per 5% increase) and serum creatinine (10.82 [1.49-78.69] per 1 mg/dL increase), platelet count <250 × 103/µL (1.92 [1.02-3.60]), lower serum sodium (1.12 [1.02-1.23 per 1 mmol/L decrease), and intravenous fluid administration initiated ≥4 days following diarrhea onset (2.50 [1.14-5.46]). A longer interval from diarrhea onset to index visit was associated with reduced HUS risk (OR, 0.70 [95% CI, .54-.90]). RRT predictors (all shown as OR [95% CI]) included female sex (2.27 [1.14-4.50]), younger age (0.83 [.74-.92] per year), lower serum sodium (1.15 [1.04-1.27] per mmol/L decrease), higher leukocyte count ≥13.0 × 103/µL (2.35 [1.17-4.72]) and creatinine (7.75 [1.20-50.16] per 1 mg/dL increase) concentrations, and initial intravenous fluid administration ≥4 days following diarrhea onset (2.71 [1.18-6.21]). CONCLUSIONS: The complex nature of STEC infection renders predicting its course a challenge. Risk factors we identified highlight the importance of avoiding dehydration and performing close clinical and laboratory monitoring.

Association between Shiga Toxin-Producing Escherichia coli O157:H7 stx Gene Subtype and Disease Severity, England, 2009-2019.

Signs and symptoms of Shiga toxin-producing Escherichia coli (STEC) serogroup O157:H7 infection range from mild gastrointestinal to bloody diarrhea and hemolytic uremic syndrome (HUS). We assessed the association between Shiga toxin gene (stx) subtype and disease severity for ¼3,000 patients with STEC O157:H7 in England during 2009-2019. Odds of bloody diarrhea, HUS, or both, were significantly higher for patients infected with STEC O157:H7 possessing stx2a only or stx2a combined with other stx subtypes. Odds of severe signs/symptoms were significantly higher for isolates encoding stx2a only and belonging to sublineage Ic and lineage I/II than for those encoding stx2a only and belonging to sublineage IIb, indicating that stx2a is not the only driver causing HUS. Strains of STEC O157:H7 that had stx1a were also significantly more associated with severe disease than strains with stx2c only. This finding confounds public health risk assessment algorithms based on detection of stx2 as a predictor of severe disease.

Effect of a bacteriophage T5virus on growth of Shiga toxigenic Escherichia coli and Salmonella strains in individual and mixed cultures.

A previously isolated a bacteriophage, vB_EcoS_AKFV33 of T5virus, demonstrated great potential in biocontrol of Shiga toxigenic Escherichia coli (STEC) O157. This study further evaluated its potential as a biocontrol agent in broth culture against other important non-O157 serogroups of STEC and Salmonella. AKFV33 was capable of lysing isolates of STEC serogroups O26 (n = 1), O145 (n = 1) and Salmonella enterica serovars (n = 6). In a broth culture microplate system, efficacy of AKFV33 for killing STEC O26:H11, O145:NM and Salmonella was improved (P < 0.05) at a lower multiplicity of infection and sampling time (6-10 h), when STEC O157:H7 was also included in the culture. This phage was able to simultaneously reduce numbers of STEC and Salmonella in mixtures with enhanced activity (P < 0.05) against O157:H7 and O26:H11, offering great promise for control of multiple zoonotic pathogens at both pre and post-harvest.

Host response to the subtilase cytotoxin produced by locus of enterocyte effacement-negative Shiga-toxigenic Escherichia coli.

Shiga-toxigenic Escherichia coli (STEC) is a major bacterium responsible for disease resulting from foodborne infection, including bloody diarrhea and hemolytic uremic syndrome. STEC produces important virulence factors such as Shiga toxin (Stx) 1 and/or 2. In the STEC family, some locus of enterocyte effacement-negative STEC produce two different types of cytotoxins, namely, Stx2 and subtilase cytotoxin (SubAB). The Stx2 and SubAB cytotoxins are structurally similar and composed of one A subunit and pentamer of B subunits. The catalytically active A subunit of SubAB is a subtilase-like serine protease and specifically cleaves an endoplasmic reticulum (ER) chaperone 78-kDa glucose-regulated protein (GRP78/BiP), a monomeric ATPase that is crucial in protein folding and quality control. The B subunit binds to cell surface receptors. SubAB recognizes sialic carbohydrate-modified cell surface proteins as a receptor. After translocation into cells, SubAB is delivered to the ER, where it cleaves GRP78/BiP. SubAB-catalyzed BiP cleavage induces ER stress, which causes various cell events including inhibition of protein synthesis, suppression of nuclear factor-kappa B activation, apoptotic cell death, and stress granules formation. In this review, we describe SubAB, the SubAB receptor, and the mechanism of cell response to the toxin.

Bacteriophage biocontrol of Shiga toxigenic Escherichia coli (STEC) O145 biofilms on stainless steel reduces the contamination of beef.

Shiga toxigenic Escherichia coli (STEC) can form biofilms and frequently cause serious foodborne illnesses. A strain of STEC O145:H25 (EC19990166) known to be a strong biofilm former was used to evaluate the efficacy of bacteriophage AZO145A against biofilms formed on stainless steel (SS) coupons. Exposure of STEC O145:H25 to phage AZO145A (1010 PFU/mL) for 2 h resulted in a 4.0 log10 reduction (P < 0.01) of planktonic cells grown in M9 broth at 24 °C for 24 h, while reductions were 2.0 log10 CFU/mL if these cells were grown for 48 h or 72 h prior to phage treatment. STEC O145 biofilms formed on SS coupons for 24, 48 and 72 h were reduced (P < 0.01) 2.9, 1.9 and 1.9 log10 CFU/coupon by phages. STEC O145 cells in biofilms were readily transferred from the surface of the SS coupon to beef (3.6 log10 CFU/coupon) even with as little as 10 s of contact with the meat surface. However, transfer of STEC O145 cells from biofilms that formed on SS coupons for 48 h to beef was reduced (P < 0.01) by 3.1 log10 CFU by phage (2 × 1010 PFU/mL) at 24 °C. Scanning electron microscopy revealed that bacterial cells within indentations on the surface of SS coupons were reduced by phage. These results suggest that bacteriophage AZO145A could be effective in reducing the viability of biofilm-adherent STEC O145 on stainless steel in food industry environments.

An Extended-Spectrum Beta-Lactamase-Producing Hybrid Shiga-Toxigenic and Enterotoxigenic Escherichia coli Strain Isolated from a Piglet with Diarrheal Disease in Northeast China.

Shiga-toxigenic Escherichia coli (STEC) and enterotoxigenic E. coli (ETEC) can cause diarrhea in piglets. This is the first report and complete genome sequence of an extended-spectrum ß-lactamase-producing hybrid STEC/ETEC strain isolated from a piglet with diarrhea on a swine farm in China. We investigated the virulence genes and phylogenetic diversity with publicly available E. coli genomes. Both E. coli strains S17-13 and S17-20 harbored multiple virulence genes, mainly including stx2e and eastA genes. Other important virulence genes (estIa, estIb, fedABCDEF, and hlyABCD) were located in the plasmid p1713-1 of S17-13, which could be transferred from E. coli S17-13 to S17-20 by conjugation. The presence of virulence genes associated with different pathogroups (STEC or ETEC) confirmed the hybrid status of E. coli strain S17-13. Phylogenetic analysis showed that STEC/ETEC S17-13, STEC S17-20, avian pathogenic E. coli (APEC) O78, and APEC ACN001 are located in the same evolutionary branch, indicating that they may originate from a common ancestor. It is crucial to understand the phylogeny of pathogenic bacteria to evaluate how they have evolved and to monitor the emergence of potential new pathogens. The emergence of novel hybrid E. coli strains presents a new public health risk. More attention must be paid to these hybrid pathogens during typing and epidemiological surveillance of E. coli infections, which challenges the traditional diagnostics of E. coli infections.

Incubation Period of Shiga Toxin-Producing Escherichia coli.

Shiga toxin-producing Escherichia coli are pathogenic bacteria found in the gastrointestinal tract of humans. Severe infections could lead to life-threatening complications, especially in young children and the elderly. Understanding the distribution of the incubation period, which is currently inconsistent and ambiguous, can help in controlling the burden of disease. We conducted a systematic review of outbreak investigation reports, extracted individual incubation data and summary estimates, tested for heterogeneity, classified studies into subgroups with limited heterogeneity, and undertook a meta-analysis to identify factors that may contribute to the distribution of the pathogen's incubation period. Twenty-eight studies were identified for inclusion in the review (1 of which included information on 2 outbreaks), and the resulting I2 value was 77%, indicating high heterogeneity. Studies were classified into 5 subgroups, with the mean incubation period ranging from 3.5 to 8.1 days. The length of the incubation period increased with patient age and decreased by 7.2 hours with every 10% increase in attack rate.

Short communication: Molecular characterization and antimicrobial resistance of pathogenic Escherichia coli isolated from raw milk and Minas Frescal cheeses in Brazil.

The aim of this study was to quantify, identify, evaluate antimicrobial resistance, and characterize the virulence factors of enteropathogenic (EPEC), Shiga-toxigenic (STEC), and enterohemorrhagic (EHEC) Escherichia coli in raw milk (RM) and legal (LMFC) and illegal (IMFC) Minas Frescal cheeses in southern and northeast Brazil. Illegal cheeses are those made without official inspection service or sanitary surveillance. We evaluated samples of RM produced in Paraná (southern) and Maranhão (northeast) States, LMFC produced using pasteurized milk in inspected industries, and IMFC potentially produced with raw milk. Mean total coliform counts were 8.4 × 104 cfu/mL for RM, 1.4 × 107 cfu/mL for LMFC, and 2.9 × 107 cfu/mL for IMFC. Mean E. coli counts were 2.4 × 103 cfu/mL for RM, 1.9 × 102 cfu/mL for LMFC, and 1.1 × 105 cfu/mL for IMFC. Among the 205 E. coli isolates from RM, 9.75% were identified as EPEC, mainly (90%) in samples from Paraná. Of the total isolates from the cheese samples, 97.4% (n = 111) came from IMFC, of which 1.8 and 2.7% were identified as EPEC and STEC, respectively; no EHEC was detected. The phylogenetic group A (60%) and typical EPEC (68%) predominated, which confirms the possible human origin of pathogenic isolates in RM and IMFC. Of these, 50% were resistant to at least one antibiotic, and streptomycin was the antimicrobial with the highest number (8) of EPEC and STEC resistant isolates. This study reports the first isolation of serogroup O28ac in Brazilian milk. We found no predominance of a specific serogroup of EPEC or STEC in milk or cheese or clonal isolates in the same sample, indicating different origins of the contamination in these products, presumably mostly related to poor hygienic handling.

Geogenomic Segregation and Temporal Trends of Human Pathogenic Escherichia coli O157:H7, Washington, USA, 2005-20141.

The often-noted and persistent increased incidence of Escherichia coli O157:H7 infections in rural areas is not well understood. We used a cohort of E. coli O157:H7 cases reported in Washington, USA, during 2005-2014, along with phylogenomic characterization of the infecting isolates, to identify geographic segregation of and temporal trends in specific phylogenetic lineages of E. coli O157:H7. Kernel estimation and generalized additive models demonstrated that pathogen lineages were spatially segregated during the period of analysis and identified a focus of segregation spanning multiple, predominantly rural, counties for each of the main clinical lineages, Ib, IIa, and IIb. These results suggest the existence of local reservoirs from which humans are infected. We also noted a secular increase in the proportion of lineage IIa and IIb isolates. Spatial segregation by phylogenetic lineage offers the potential to identify local reservoirs and intervene to prevent continued transmission.

Molecular Epidemiology of Shiga Toxin-Producing Escherichia coli (STEC) on New Zealand Dairy Farms: Application of a Culture-Independent Assay and Whole-Genome Sequencing.

New Zealand has a relatively high incidence of human cases of Shiga toxin-producing Escherichia coli (STEC), with 8.9 STEC cases per 100,000 people reported in 2016. Previous research showed living near cattle and contact with cattle feces as significant risk factors for STEC infections in humans in New Zealand, but infection was not linked to food-associated factors. During the 2014 spring calving season, a random, stratified, cross-sectional study of dairy farms (n = 102) in six regions across New Zealand assessed the prevalence of the "Top 7" STEC bacteria (serogroups O157, O26, O45, O103, O111, O121, and O145) in young calves (n = 1,508), using a culture-independent diagnostic test (PCR/MALDI-TOF). Twenty percent (306/1,508) of calves on 75% (76/102) of dairy farms were positive for at least one of the "Top 7" STEC bacteria. STEC carriage by calves was associated with environmental factors, increased calf age, region, and increased number of calves in a shared calf pen. The intraclass correlation coefficient (ρ) indicated strong clustering of "Top 7" STEC-positive calves for O157, O26, and O45 serogroups within the same pens and farms, indicating that if one calf was positive, others in the same environment were likely to be positive as well. This finding was further evaluated with whole-genome sequencing, which indicated that a single E. coli O26 clonal strain could be found in calves in the same pen or farm, but different strains existed on different farms. This study provides evidence that would be useful for designing on-farm interventions to reduce direct and indirect human exposure to STEC bacteria.IMPORTANCE Cattle are asymptomatic carriers of Shiga toxin-producing E. coli (STEC) bacteria that can cause bloody diarrhea and kidney failure in humans if ingested. New Zealand has relatively high numbers of STEC cases, and contact with cattle feces and living near cattle are risk factors for human infection. This study assessed the national prevalence of STEC in young dairy cattle by randomly selecting 102 farms throughout New Zealand. The study used a molecular laboratory method that has relatively high sensitivity and specificity compared to traditional methods. "Top 7" STEC was found in 20% of calves on 75% of the farms studied, indicating widespread prevalence across the country. By examining the risk factors associated with calf carriage, potential interventions that could decrease the prevalence of "Top 7" STEC bacteria at the farm level were identified, which could benefit both public health and food safety.

Management of Shiga toxin producing Escherichia coli-infected children: A multi-national, multi-specialty survey.

AIM: Research has highlighted the potential role that hydration status may play in predicting outcomes in Shiga toxin-producing Escherichia coli (STEC)-infected children. Because little is known about the management of STEC-infected children in the pre-haemolytic uremic syndrome phase, we compared paediatric emergency medicine and nephrologist-stated management approaches to STEC-infected children. METHODS: Members of the Pediatric Emergency Research Canada (PERC; n = 228), the Pediatric Emergency Medicine Collaborative Research Committee (PEM CRC; n = 221) and the Canadian Association of Pediatric Nephrologists (CAPN; n = 66) were surveyed. Five individualised e-mail requests containing a link to a 42-question web-based survey were sent to eligible participants. RESULTS: Of 496 potentially eligible participants, 276 (56%) submitted complete survey responses. In children with classic features of STEC infection, baseline haemoglobin/haematocrit is obtained by 54% of PERC, 41% of PEM CRC and 83% of CAPN members (P < 0.001), and baseline renal function is obtained by 51% of PERC, 38% of PEM CRC and 83% of CAPN members (P < 0.001). Intravenous fluids are more often recommended by nephrologists (28%) compared with PEM physicians (7%), P < 0.001. In children with known E. coli O157:H7 infection, nephrologists more commonly recommend clinical follow-up (P = 0.003), complete blood counts (P < 0.001) and renal function/electrolyte testing (P < 0.001). Intravenous fluid administration and admission are more commonly recommended by nephrologists (P = 0.03 and P < 0.001, respectively). CONCLUSION: Compared with paediatric nephrologists, paediatric emergency medicine physicians are less likely to perform baseline and follow-up blood tests and to administer intravascular volume expansion in children at risk of, and with confirmed, E. coli O157:H7 infection.

[Development of a product anti-Shiga toxin for prevention of the hemolytic uremic syndrome]. / Desarrollo de un producto anti-toxina Shiga para la prevención del síndrome urémico hemolítico.

The typical hemolytic uremic syndrome (HUS) is an orphan disease caused by Shiga toxin(Stx) producing Escherichia coli strains and characterized by acute kidney damage, microangiopathic hemolytic anemia and low platelet count. It is endemic in Argentina, the country with the highest incidence of HUS in the world. Stx is essential for its development and therefore, HUS is considered a toxemic non-bacteremic disorder, which could be treated with antibodies. Herein we describe the development of a new treatment capable of neutralizing the toxic effect of Stx and its variants. The treatment consists of F(ab')2 fragments from an equine antiserum whose efficacy and potency against Stx1 and Stx2 were proved in different preclinical models. The product was shown to be safe in animals. Furthermore, the anti-Stx F(ab')2 pharmacokinetic was shown to be similar to that of analogous compounds and a therapeutic window for its administration was determined. Altogether, these preclinical results warrant testing in humans. The phase I clinical trial will be performed at the Hospital Italiano in Buenos Aires to evaluate the safety and pharmacokinetics of the product in healthy adult volunteers. Based on the results of this study, a phase II clinical trial will be planned in pediatric patients diagnosed with infection by Stx-producing E. coli strains.

[Characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli in animal feces, from Shandong Province].

Objective: To understand the infection status, characteristics and drug resistance of non-O157 Shiga toxin-producing E. coli (STEC) in animal feces in Shandong Province. Methods: From 2015 to 2016, convient sampling method was used to collect 1 022 fresh feces of animals in Weishan county and Laizhou city, and 24 non-O157 STEC were isolated. The serotypes of non-O157 STEC strains were confirmed through serum agglutination test. The susceptibility was explored through the antimicrobial sensitivity experiments. ESBLs activity was confirmed by double-disc diffusion. PCR method was used to detect the resistance genes. PFGE typing was operated to assess the relatedness and variability of the strains. The multi-locus sequence typing (MLST) was adopted to get the allelic profile and ST sequence of strains. Analysis was made on the evolutionary relationship between different ST groups was made through CLC Sequence Viewer and Counting Express. Results: A total of 24 non-O157 STEC were isolated from animal feces. 23 strains were from pig feces, and 1 strain was from cow feces, and the serotypes were more dispersed. All of the 24 strains carried stx2 genes. The highest resistance rate was sulfamethoxazole(22 strains), the mount of cotrimoxazole and nalidixic acid was 18 strains, chloramphenicol was 13 strains, tetracycline was 19, and there was a phenomenon of multiple drug resistance. The drug resistance spectrum was sulfamethoxazole tetracycline-compound novammin-naphthidine-chloramphenicol. All strains were sensitive to cefepime and imipenem. The ESBLs confirmatory test showed that 4 strains of non O157 STEC produced beta lactamase. PCR detected 7 resistance genes, and 4 tetracycline resistance genes (Tet A, Tet B, tetC and tetD) were detected. The beta lactamase resistance genes (blaSHV-1, bla CTX-M, bla TEM) were all negative. 24 strains were divided into 15 PFGE types, and their clustering results were more dispersed and no dominant PFGE type. There were 11 kinds of MLST types, most of them are ST540 and ST5133 types, each of which was 4 strains, and clustered into 1 MLST genomes. Conclusion: The serotypes of non-O157 STEC in animal feces O157 STEC were dispersed, and the resistant rate to common antibiotic was high. MLST typing results presents obvious polymorphism. Surveillance and manage ment of these strains should be strengthened.

Shiga Toxin-Producing Escherichia coli O157, England and Wales, 1983-2012.

We evaluated clinical Shiga toxin-producing Escherichia coli O157 infections in England and Wales during 1983-2012 to describe changes in microbiological and surveillance methods. A strain replacement event was captured; phage type (PT) 2 decreased to account for just 3% of cases by 2012, whereas PT8 and PT21/28 strains concurrently emerged, constituting almost two thirds of cases by 2012. Despite interventions to control and reduce transmission, incidence remained constant. However, sources of infection changed over time; outbreaks caused by contaminated meat and milk declined, suggesting that interventions aimed at reducing meat cross-contamination were effective. Petting farm and school and nursery outbreaks increased, suggesting the emergence of other modes of transmission and potentially contributing to the sustained incidence over time. Studies assessing interventions and consideration of policies and guidance should be undertaken to reduce Shiga toxin-producing E. coli O157 infections in England and Wales in line with the latest epidemiologic findings.

Short communication: Isolation of Shiga toxin-producing Escherichia coli in raw milk and mozzarella cheese in southern Italy.

Shiga toxin-producing Escherichia coli (STEC) are a significant food-borne public health hazard in Europe, where most human infections are associated with 5 serogroups (O157, O26, O103, O145, and O111). In 2015, 95 food and environmental samples were examined for the presence of Shiga toxin genes (stx1 and stx2). The STEC were isolated from 2 raw milk and 1 mozzarella cheese samples that were collected in the period between June and September. To the best of our knowledge, this finding represents the first report of STEC isolation from mozzarella cheese produced in Italy, and it suggests that both the quality of raw milk used to produce mozzarella and the thermal inactivation treatment associated with the curd-stretching step should be carefully monitored.