Healthcare-associated foodborne outbreaks in high-income countries: a literature review and surveillance study, 16 OECD countries, 2001 to 2019

Effects of the histone-like protein on biofilm formation and pathogenicity of Listeria monocytogenes

Histone-like protein HU is essential for DNA recombination, repair, and transcriptional regulation in bacteria. However, the physiological roles of HU proteins in Listeria monocytogenes (LmHU) remain unexplored. Given the significant biofilm-forming ability of this foodborne pathogen and its associated cross-contamination risks, identifying novel control targets is critical. LmHU, as the sole double-stranded DNA-binding protein in L. monocytogenes, is a promising candidate. This study systematically explored its contributions to biofilm formation, motility, and the regulation of virulence factors. The results indicated that high levels of LmHU in vivo promoted cell cohesion, leading to a chain-like structure among L. monocytogenes. Additionally, LmHU could be secreted into the biofilm matrix, reinforcing the structure by interacting with extracellular polymeric substances. However, elevated LmHU levels inhibited bacterial motility, flagellar synthesis, and host invasion in Caco-2 cells. RNA-seq analysis revealed 374 differentially expressed genes in the Lmhu mutant relative to the wild-type strain, supporting these findings. Further enrichment analysis and validation experiments suggested that Lmhu overexpression impaired trehalose utilization. These results indicate that LmHU may serve as a potential target for novel disinfectants or therapies to reduce risks associated with L. monocytogenes in food safety and public health.

Hospital-wide healthcare-associated carbapenemase-producing Enterobacterales outbreak: risks of electric floor scrubbers in catering facilities and kitchens

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are associated with poor clinical outcomes and can spread rapidly in healthcare settings. Environmental reservoirs are increasingly recognized as playing an important part in some nosocomial outbreaks.

AIM

To describe the investigation and control of a CPE outbreak, lasting several years, across two separate hospital sites within one organization.

METHODS

Investigation of multiple ward-level CPE cross-transmissions with a number of sporadic cases. Environmental sampling of ward environments, catering facilities and electric floor scrubbers was undertaken.

FINDINGS

Eleven patients over a 19-month period were identified as carrying healthcare-associated New Delhi metallo-beta-lactamase (NDM)-producing Enterobacter cloacae, and a further patient carried NDM Escherichia coli. E. cloacae isolates were indistinguishable on pulsed-field gel electrophoresis typing, supporting acquisition with a single point source. Environmental sampling found contamination of the electric floor scrubbers used for cleaning the hospital catering facilities and in the associated toilets. Standard outbreak response measures achieved control of ward outbreaks. Sporadic cases and hospital-wide cross-transmission were controlled after interventions on the central food-handling unit and by decommissioning affected floor scrubbers. Electric floor scrubbers were found to have the potential to disperse Gram-negative bacteria into the surrounding environment under experimental conditions.

CONCLUSION

This outbreak report demonstrates that catering facilities and kitchens can be involved in widespread healthcare outbreaks of enteric organisms. This is also the first report of the potential role of electric floor scrubbers in causing significant environmental contamination with CPE which may indicate a role in nosocomial transmission.

Dairy farmers' knowledge about milk-borne zoonosis in the Eastern Cape province, South Africa

Foodborne zoonosis is a longstanding global issue that limits and continues to threaten the food production industry and public health in several countries. The study's objective was to evaluate the dairy farmers' knowledge, attitudes, and practices about milkborne pathogens in the Eastern Cape province, South Africa. A total of 139 dairy farmers were interviewed using a semi-structured online questionnaire. The pathogens of interest were Brucella spp., Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Cryptosporidium. Only 20.9% of dairy farmers reported knowledge of Brucella spp. as a milk-borne pathogen. The most known pathogen was E. coli (54.7%), followed by Listeria spp. (41.0%), Staphylococcus spp. (38.8%), and Salmonella spp. (35.3%). In this study, knowledge of milk-borne pathogens was statistically associated (p<0.05) with workplace position. Only a few participants (37.2%) showed knowledge of abortion as an important clinical sign of foodborne pathogens. Also, 84.1% of dairy farmers indicated that they consume unpasteurized milk and sour milk (77%). Some respondents (18.0%) do not believe assisting a cow during calving difficulty without wearing gloves is a risk factor for zoonosis. Knowledge assessment is essential in developing countries that have experienced a foodborne outbreak, such as South Africa. There is an urgent need to educate dairy farmers about milk-borne zoonosis to minimize the threat to food security and public health.

Detection of human enteric viruses in fresh produce of markets, farms and surface water used for irrigation in the Tehran, Iran

Considering the major role of vegetables in the transmission of gastrointestinal diseases, investigation of the presence of gastrointestinal viruses is particularly important for public health. Additionally, monitoring and investigating potential points of contamination at various stages of cultivation, harvesting, and distribution can be important in identifying the sources of transmission. This study was conducted with the aim of identifying norovirus, adenovirus, hepatitis A virus, hepatitis E virus, rotaviruses, and astroviruses in vegetable samples from the fields and fruit and vegetable centers of Tehran City, and to investigate their presence in irrigation water by RT-qPCR. This study was carried out in two phases: initial and supplementary. During phase I, a total of 3 farms and 5 fruit and vegetable centers and a total of 35 samples from farms, 102 samples from fruit and vegetable centers and 8 agricultural water samples were collected. Zero, 16 and 1 samples were positive for at least one of the viruses from each of the sources, respectively. During phase II, 88 samples from 23 farms, 226 samples from 50 fruit and vegetable centers and 16 irrigation water samples were collected, with 23, 57 and 4 samples were positive for at least one virus, respectively. Rotavirus was the most frequently identified virus among the samples, followed by NoV GII, NoV GI, AstV, and AdV. HAV and HEV were not detected in any of the tested samples. The results of this study suggest that there may be a wide presence of viruses in vegetables, farms, and fruit and vegetable centers in Tehran City, which could have significant consequences considering the fact that many of these foods are consumed raw. Additionally, the detection of some of these viruses in irrigation water suggests that this may be a potential route for viral contamination of produce.

Ligilactobacillus salivarius 7247 Strain: Probiotic Properties and Anti-Salmonella Effect with Prebiotics

The Ligilactobacillus salivarius 7247 (LS7247) strain, originally isolated from a healthy woman's intestines and reproductive system, has been studied for its probiotic potential, particularly against Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) as well as its potential use in synbiotics. LS7247 showed high tolerance to gastric and intestinal stress and effectively adhered to human and animal enterocyte monolayers, essential for realizing its probiotic properties. LS7247 showed high anti-Salmonella activity. Additionally, the cell-free culture supernatant (CFS) of LS7247 exhibited anti-Salmonella activity, with a partial reduction upon neutralization with NaOH (p < 0.05), suggesting the presence of anti-Salmonella factors such as lactic acid (LA) and bacteriocins. LS7247 produced a high concentration of LA, reaching 124.0 ± 2.5 mM after 48 h of cultivation. Unique gene clusters in the genome of LS7247 contribute to the production of Enterolysin A and metalloendopeptidase. Notably, LS7247 carries a plasmid with a gene cluster identical to human intestinal strain L. salivarius UCC118, responsible for class IIb bacteriocin synthesis, and a gene cluster identical to porcine strain L. salivarius P1ACE3, responsible for nisin S synthesis. Co-cultivation of LS7247 with SE and ST pathogens reduced their viability by 1.0-1.5 log, attributed to cell wall damage and ATP leakage caused by the CFS. For the first time, the CFS of LS7247 has been shown to inhibit adhesion of SE and ST to human and animal enterocytes (p < 0.01). The combination of Actigen prebiotic and the CFS of LS7247 demonstrated a significant combined effect in inhibiting the adhesion of SE and ST to human and animal enterocytes (p < 0.001). These findings highlight the potential of using the LS7247 as a preventive strategy and employing probiotics and synbiotics to combat the prevalence of salmonellosis in animals and humans caused by multidrug resistant (MDR) strains of SE and ST pathogens.

Epidemiological Features of Foodborne Disease Outbreaks in Catering Service Facilities - China, 2010-2020

INTRODUCTION

In terms of food preparation settings, catering service facilities have been identified as locations with the highest incidence of foodborne disease outbreaks in China. Since 2010, the China National Center for Food Safety Risk Assessment has established the Foodborne Disease Outbreak Surveillance System (FDOSS) to monitor foodborne disease outbreaks. Consequently, data from the FDOSS has provided a more accurate depiction of the epidemic characteristics of outbreaks within these facilities.

METHODS

From 2010 to 2020, the FDOSS gathered data related to the prevalence of outbreaks, cases, hospitalizations, and deaths linked to foodborne disease outbreaks in catering service facilities. This study examined the temporal and geographical distribution, pathogenic factors, and contributing variables of these outbreaks over the course of the decade.

RESULTS

From 2010 to 2020, China's catering service facilities reported 18,331 outbreaks, which resulted in 206,718 illnesses, 68,561 hospitalizations, and 201 deaths. The second and third quarters of the year accounted for 76.12% of the outbreaks and 72.93% of the cases. The primary pathogenic factors were pathogenic organisms, which caused 4,883 (26.64%) outbreaks, 94,047 (45.50%) cases, 32,170 (46.92%) hospitalizations, and 21 (10.45%) deaths. There were 5,607 (30.59%) outbreaks in restaurants, 2,876 (15.69%) outbreaks from street vendors, and 2,560 (13.97%) outbreaks in employee canteens in China.

CONCLUSIONS

The implementation of relevant control methods, including health education and promotion, is critical for addressing foodborne diseases in catering service facilities. Regular food safety training sessions for restaurant personnel and managers are essential to ensuring the effective management of these health risks.

Spatio-temporal distribution and influencing factors of norovirus outbreaks in Beijing, China from 2016 to 2020

BACKGROUND

Noroviruses are a leading cause of acute gastroenteritis (AGE) worldwide. The geographical characteristics of norovirus outbreaks in Beijing and their influencing factors remain unknown. This study aimed to explore the spatial distributions, geographical characteristics, and influencing factors of norovirus outbreaks in Beijing, China.

METHODS

Epidemiological data and specimens were collected through the AGE outbreak surveillance system in all 16 districts of Beijing. Data on spatial distribution, geographical characteristics, and influencing factors of norovirus outbreaks were analyzed using descriptive statistics methods. We measured spatial, geographical clustering of high- or low-value deviance from random distribution using Z-scores and P-values as statistical significance measures with Global Moran's I statistics and Getis-Ord Gi in ArcGIS. Linear regression and correlation methods were used to explore influencing factors.

RESULTS

Between September 2016 and August 2020, 1,193 norovirus outbreaks were laboratory-confirmed. The number of outbreaks varied seasonally, typically peaking in spring (March to May) or winter (October to December). Outbreaks primarily occurred around central districts at the town level, and spatial autocorrelation was evident in both the entire study period and in individual years. Hotspots of norovirus outbreaks in Beijing were primarily found in contiguous areas between three central districts (Chaoyang, Haidian, Fengtai) and four suburban districts (Changping, Daxing, Fangshan, Tongzhou). The average population numbers, mean number of all schools, and mean number of kindergartens and primary schools for towns in central districts and hotspot areas were higher than those in suburban districts and non-hotspot areas respectively. Additionally, population numbers and densities of kindergartens and primary schools were influencing factors at the town level.

CONCLUSIONS

Hotspots of norovirus outbreaks in Beijing were in contiguous areas between central and suburban districts with high populations, and high kindergarten and primary school densities were the likely driving forces. Outbreak surveillance needs to focus on contiguous areas between central and suburban districts with increased monitoring, medical resources, and health education.

Human Listeriosis

Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that can cause severe invasive infections upon ingestion with contaminated food. Clinically, listerial disease, or listeriosis, most often presents as bacteremia, meningitis or meningoencephalitis, and pregnancy-associated infections manifesting as miscarriage or neonatal sepsis. Invasive listeriosis is life-threatening and a main cause of foodborne illness leading to hospital admissions in Western countries. Sources of contamination can be identified through international surveillance systems for foodborne bacteria and strains' genetic data sharing. Large-scale whole genome studies have increased our knowledge on the diversity and evolution of L. monocytogenes, while recent pathophysiological investigations have improved our mechanistic understanding of listeriosis. In this article, we present an overview of human listeriosis with particular focus on relevant features of the causative bacterium, epidemiology, risk groups, pathogenesis, clinical manifestations, and treatment and prevention.

Presence of Certain Foodborne Pathogens in Traditional Balearic Islands' Meat, Pastry, and Cheese Specialties Supported by European Union Quality Schemes, from 2018 to 2021

The cuisine of the Balearic Islands (Spain, southern Europe) has several products of a great tradition, recognized worldwide and covered by European Union quality schemes, such as Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI). Among them, the most emblematic products are sobrasada de Mallorca (a type of raw curated pork meat), ensaimada de Mallorca (pastry product), and Mahón-Menorca cheese (cow's milk cheese). During 4 consecutive years (2018-2021), the presence/absence of Escherichia coli β-glucuronidase positive (henceforth as E. coli), Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus in these products has been monitored, as well as the total yeast and mold count in ensaimada de Mallorca. The results of the microbiological analysis showed that sobrasada presented similar microbiological patterns to those of other raw curated meat products (some presence of E. coli and L. monocytogenes). Furthermore, the sobrasada de Mallorca made with white pork tended to be positive in E. coli compared to other sobrasada subtypes. In the case of ensaimada, only a reduced number of cases within filled ensaimadas (with higher moisture content) presented unacceptable mold and yeast counts (>500 colony-forming unit [CFU]/g). Finally, the Mahón-Menorca cheese presented a surprising microbiology pattern: higher E. coli contamination in the pasteurized milk cheese compared to its raw counterpart. This pattern was observed for all the years, being statistically significant in 2020. This study has detected good microbiological status in the three traditional products studied. However, worrisome issues in Good Hygienic Practices have been detected for some companies that produce pasteurized milk Mahón-Menorca cheese under the PDO quality label. The companies involved and even the competent authorities should address these problems to correct this deviation in food security.