Prevalence and serotypes of Salmonella associated with goats at two Australian abattoirs

Salmonella serovars in sheep and goats and their probable zoonotic potential to humans in Suez Canal Area, Egypt

Background

Salmonella is one of the most common and economically important zoonotic pathogens. This study aimed to determine the occurrence of Salmonella serovars in sheep and goats and their probable zoonotic risk to humans in Suez Canal area in Egypt. A total of 320 fecal samples from sheep (n = 120), goats (n = 100), and humans (n = 100) were collected and examined for the presence of Salmonella based on cultural and biochemical characteristics, and serological analysis. Moreover, the virulence of the identified Salmonella isolates was assessed by molecular screening for invA, stn, spvC, and sopB virulence genes using PCR.

Results

Overall, the occurrence of Salmonella in sheep feces (23.3%) was higher than that in goat feces (7%) and human stool (13%) in the study area. The identified isolates belonged to 12 serotypes; ten, five, and eight from sheep, goats, and humans, respectively. The most frequently identified serotypes were S. Typhimurium from sheep feces, and S. Enteritidis from both goat feces and human stool, with four serotypes; S. Typhimurium, S. Enteritidis, S. Dublin and S. Saintpaul, were mutually shared between all of them. Demographic data revealed that diarrheic sheep (85.7%) and goats (25%) had a higher risk for Salmonella fecal carriage than non-diarrheic ones (19.5% and 6.25%, respectively). The prevalence of Salmonella infection in humans in contact with sheep and goats (28%) was significantly higher than its prevalence in people having a history of contact with animals other than sheep and goats (10%) and those having no history of animal contact (7.3%) (χ² = 6.728, P ˂ 0.05). The stn, spvC, and sopB genes were detected in 98.1% of the isolates, with a significant, very strong positive correlation for their mutual presence (P < 0.05). Approximately 40.7% of isolates that carried the invA gene had a non-significant, very weak positive correlation with other virulence genes. The most common genotypic virulence profile for all isolates was stn, spvC, and sopB; however, invA, stn, spvC, and sopB was the frequent virulotype for S. Typhimurium, S. Tsevie, S. Apeyeme, and S. Infantis.

Conclusions

The present study highlights the role of apparently healthy and diarrheic sheep and goats as reservoirs and sources of human infection with virulent Salmonella serovars in the Suez Canal area.

Literature Review: Coinfection in Young Ruminant Livestock-Cryptosporidium spp. and Its Companions

The protozoan Cryptosporidium parvum is one of the major causative pathogens of diarrhoea in young ruminants; therefore, it causes economic losses and impairs animal welfare. Besides C. parvum, there are many other non-infectious and infectious factors, such as rotavirus, Escherichia coli, and Giardia duodenalis, which may lead to diarrhoeic disease in young livestock. Often, more than one infectious agent is detected in affected animals. Little is known about the interactions bet-ween simultaneously occurring pathogens and their potential effects on the course of disease. In this review, a brief overview about pathogens associated with diarrhoea in young ruminants is presented. Furthermore, information about coinfections involving Cryptosporidium is provided.

High-throughput sequencing technologies in the detection of livestock pathogens, diagnosis, and zoonotic surveillance

Increasing globalization, agricultural intensification, urbanization, and climatic changes have resulted in a significant recent increase in emerging infectious zoonotic diseases. Zoonotic diseases are becoming more common, so innovative, effective, and integrative research is required to better understand their transmission, ecological implications, and dynamics at wildlife-human interfaces. High-throughput sequencing (HTS) methodologies have enormous potential for unraveling these contingencies and improving our understanding, but they are only now beginning to be realized in livestock research. This study investigates the current state of use of sequencing technologies in the detection of livestock pathogens such as bovine, dogs (Canis lupus familiaris), sheep (Ovis aries), pigs (Sus scrofa), horses (Equus caballus), chicken (Gallus gallus domesticus), and ducks (Anatidae) as well as how it can improve the monitoring and detection of zoonotic infections. We also described several high-throughput sequencing approaches for improved detection of known, unknown, and emerging infectious agents, resulting in better infectious disease diagnosis, as well as surveillance of zoonotic infectious diseases. In the coming years, the continued advancement of sequencing technologies will improve livestock research and hasten the development of various new genomic and technological studies on farm animals.

Survival of Salmonella Under Heat Stress is Associated with the Presence/Absence of CRISPR Cas Genes and Iron Levels

Clustered regularly interspaced short palindromic repeats (CRISPR) cas genes have been linked to stress response in Salmonella. Our aim was to identify the presence of CRISPR cas in Salmonella and its response to heat in the presence of iron. Whole genomes of Salmonella (n = 50) of seven serovars were compared to identify the presence of CRISPR cas genes, direct-repeats and spacers. All Salmonella genomes had all cas genes present except S. Newport 2393 which lacked these genes. Gene-specific primers were used to confirm the absence of these genes in S. Newport 2393. The presence/absence of CRISPR cas genes was further investigated among 469 S. Newport genomes from PATRIC with 283 genomes selected for pan-genome analysis. The response of eleven Salmonella strains of various serovars to gradual heat in ferrous and ferric forms of iron was investigated. A total of 32/283 S. Newport genomes that lacked all CRISPR cas genes clustered together. S. Newport 2393 was the most heat-sensitive strain at higher iron levels (200 and 220 pm) in ferrous and ferric forms of iron. The absence of CRISPR cas genes in S. Newport 2393 may contribute to its increase in heat sensitivity and iron may play a role in this. The high reduction in numbers of most Salmonella strains exposed to heat makes it unfeasible to extract RNA and conduct transcription studies. Further studies should be conducted to validate the survival of Salmonella when exposed to heat in the presence/absence of CRISPR cas genes and different iron levels.

Survival of Salmonella on Red Meat in Response to Dry Heat

ABSTRACT

Red meat is associated with Salmonella outbreaks, resulting in negative impacts for the processing industry. Little work has been reported on the use of dry heat as opposed to moist heat against Salmonella on red meat. We determined the effect of drying at 25°C and dry heat at 70°C with ∼10% relative humidity for 1 h against 11 Salmonella strains of multiple serovars on beef, lamb, and goat and rubber as an inert surface. Each strain at ∼108 CFU/mL was inoculated (100 μL) onto ±1 g (1 cm2) of each surface and allowed to attach for 15 min in a microcentrifuge tube. Samples were then exposed to 70 and 25°C with ∼10% relative humidity in a heating block. Surviving Salmonella numbers on surfaces were enumerated on a thin agar layer medium. If numbers were below the limit of detection (2.01 log CFU/cm2), Salmonella cells were enriched before plating to determine the presence of viable cells. Water loss (percent) from meat after at 25 and 70°C was determined. Whole genomes of Salmonella were interrogated to identify the presence-absence of stress response genes (n = 30) related to dry heat that may contribute to the survival of Salmonella. The survival of Salmonella at 25°C was significantly higher across all surfaces (∼6.09 to 7.91 log CFU/cm2) than at 70°C (∼3.66 to 6.33 log CFU/cm2). On rubber, numbers of Salmonella were less than the limit of detection at 70°C. Water loss at 70°C (∼17.72 to 19.89%) was significantly higher than at 25°C (∼2.98 to 4.11%). Salmonella cells were not detected on rubber, whereas survival occurred on all red meat at 70°C, suggesting its protective effect against the effect of heat. All Salmonella strains carried 30 stress response genes that likely contributed to survival. A multi-antibiotic-resistant Salmonella Typhimurium 2470 exhibited an increase in heat resistance at 70°C on beef and lamb compared with other strains. Our work shows that dry heat at 70°C for 1 h against Salmonella on red meat is not a practical approach for effectively reducing or eliminating them from red meat.

HIGHLIGHTS

Salmonella survival after exposure to heat in a model meat juice system

The effect of heat against eleven Salmonella strains in model meat juices was examined. Juices from beef, lamb and goat were made from either the fatty layer (FL), muscle (M) or a mixture of both (FLM). The pH of each FLM sample was altered to match the pH of PBS and vice versa to determine the pH effect on the survival of Salmonella against the effect of heat. Salmonella were exposed to either gradual heating to 70 °C in FLM, M and FL or heat shock at 70 °C for 5 min in FLM. Fat, fatty acid profile and iron content of the juices were determined. Gradual heat treatment significantly (p ≤ 0.05) reduced Salmonella as compared to the untreated controls (~1.92-7.61 log CFU ml^-1) while heat shock significantly (p ≤ 0.05) reduced Salmonella as compared to the untreated controls (~5.80-7.36 log CFU ml^-1). Survival of Salmonella was higher in lamb juices than other juices. The fat content in lamb FL (3.25%) was significantly higher (p ≤ 0.05) than beef (1.30%) and goat FL (1.42%). Iron content in lamb FLM (~127 mg kg^-1) was significantly (p ≤ 0.05) lower than beef (~233 mg kg^-1) and goat FLM (~210 mg kg^-1). The omega 6 and linoleic acid content in goat FLM (~36.0% and ~34.4%) was significantly higher (p ≤ 0.05) than beef (~29.1% and ~27.1%). Fat, fatty acids and iron may differentially protect Salmonella against the effect of heat in these juices.

Salmonella Hessarek Gastroenteritis with Bacteremia: A Case Report and Literature Review

Salmonella enterica subspecies enterica serotype Hessarek (Salmonella Hessarek) is considered a serovar with high host specificity and is an uncommon cause of disease in humans; no cases of S. Hessarek bacteremia have been reported in humans to date. On 16 July 2019, a young male presented abdominal pain, vomit, diarrhea, and fever up to 41 °C, a few hours after a kebab meal containing goat meat; he went to the Emergency Room, where a Film Array^® GI Panel (BioFire, Biomerieux Company, Marcy-L´Étoile, France) was performed on his feces and results were positive for Salmonella. The culture of the feces was negative, but the blood culture was positive for Salmonella spp., which was identified as Salmonella Hessarek by seroagglutination assays. The patient was treated with ceftriaxone 2 g intravenously qd for 8 days; he was discharged in good general conditions, and ciprofloxacin 500 mg per os bid for 7 more days was prescribed, after exclusion of endocarditis and of clinical signs of complicated bacteremia. This case of Salmonella Hessarek gastroenteritis with bacteremia is probably the first case of bloodstream human infection due to this agent ever described. Further studies are needed to ascertain the global burden of S. Hessarek disease in humans.

Non-Typhoidal Salmonella at the Human-Food-of-Animal-Origin Interface in Australia

Non-typhoidal Salmonella is a major zoonotic pathogen that plays a significant role in foodborne human salmonellosis worldwide through the consumption of contaminated foods, particularly those of animal origin. Despite a considerable reduction in human salmonellosis outbreaks in developed countries, Australia is experiencing a continuous rise of such outbreaks in humans. This review of the literature highlights the reported non-typhoidal Salmonella outbreaks in humans as well as the occurrence of the pathogen in foods from animal sources throughout Australia. Non-typhoidal Salmonella infections from food animals are more often associated with at-risk people, such as immunocompromised and aged people or children. Although several animal-sourced foods were recognised as the catalysts for salmonellosis outbreaks in Australia, egg and egg-based products remained the most implicated foods in the reported outbreaks. This review further highlights the antimicrobial resistance trends of non-typhoidal Salmonella isolates at the human-food interface, with a focus on clinically important antimicrobials in humans, by collating evidence from previous investigations in Australia. The rise in antimicrobial-resistant Salmonella, especially to antimicrobials commonly prescribed to treat human salmonellosis, has become a significant global public health concern. However, the overall prevalence of antimicrobial resistance in Australia is considerably lower than in other parts of the world, particularly in terms of critically important antimicrobials for the treatment of human salmonellosis. The present review adds to our understanding of the global epidemiology of non-typhoidal Salmonella with emphasis on the past few decades in Australia.

Draft Genome Sequences of Four Antibiotic-Resistant Salmonella Strains Isolated from Australian Red Meat Animal Species

The genome sequences of four antibiotic-resistant Salmonella strains isolated from red meat animals in Australia are presented. Multidrug-resistant Salmonella enterica serovar Heidelberg 329 and Salmonella enterica serovar Typhimurium 2470 harbored an IncHI2 plasmid similar to the multidrug-resistant S. Heidelberg strain N13-01290 plasmid pN13-01290_23 previously isolated in Canada.

Comparative Genomics and Phenotypic Investigations Into Antibiotic, Heavy Metal, and Disinfectant Susceptibilities of Salmonella enterica Strains Isolated in Australia

Salmonella enterica is recognized as a major contributor of gastrointestinal illness worldwide. Concerns have been raised over the increasing prevalence of antibiotic resistant strains of Salmonella isolated from animals and food, and the role of antibiotics and other antimicrobial agents such as biocides and heavy metals in the selection and dissemination of antibiotic resistant bacteria to human hosts. In this study the antibiotic, heavy metal and disinfectant resistance genotypes and phenotypes of 19 S. enterica isolates from food-producing animals were established using whole genome sequence analysis, disc diffusion, as well as broth or agar dilution methods. This study also investigated the genomic environment of resistance genes on mobile genetic elements and chromosomal DNA. An ampicillin and streptomycin resistant S. Infantis isolate in this study harbored a β-lactamase (bla_TEM–1), and two streptomycin resistance conferring genes (strA and strB) on a class 1 integron mobilized on a large conjugative plasmid. This plasmid also harbored two arsenic resistance gene cassettes. The arsenic resistance cassette, arsRCDAB, was also observed in two S. Singapore isolates with high tolerance to arsenate. A nalidixic acid resistant S. Typhimurium isolate was found to possess a mutation in gyrA resulting in amino acid change Asp87Gly and tetracycline resistant S. Typhimurium isolate was found to harbor efflux pump gene, tetA. No resistance (genotypic or phenotypic) was recorded to the disinfectants screened in this study. Taken together, results of this study showed a good correlation between predicted and measured resistances when comparing genotypic and phenotypic data, respectively. The findings of this study do not suggest resistance to clinically relevant antibiotics are widespread among Salmonella isolated from Australian food-producing animals.

Salmonella enterica isolates from Western Australian rangeland goats remain susceptible to critically important antimicrobials

This study investigated faecal carriage and antimicrobial resistance (AMR) of Salmonella enterica recovered from rangeland goats. Faecal samples (n = 400) were collected at slaughter from four consignments of goats (n = 100 samples per consignment), each from one of four localities in Western Australia. Carriage of Salmonella spp. was detected in 106 samples (26.5%; 95% CI 22.4-31.0%). The rate of faecal carriage for each consignment ranged between 23-30%. PCR assays targeting the STM2755 and STM4497 genes revealed 84.9% (90/106) of the isolates were of serovar Typhimurium. Salmonella Chester (11/106, 10.4%) and S. Saintpaul (5/106, 4.7%) were characterised at invA and ompF genes. Antimicrobial susceptibility testing demonstrated that 84.0% of isolates were susceptible to all tested (n = 13) antimicrobials. Resistance was identified to azithromycin (14.2%), tetracycline (10.4%), ampicillin (5.7%), amoxicillin-clavulanate and cefoxitin (3.8%), trimethoprim/sulfamethoxazole (1.9%), gentamicin and streptomycin (0.9%). No isolate was resistant to four or more antimicrobials, or to critically important antimicrobials such as fluoroquinolones and extended spectrum cephalosporins. This is the first study reporting AMR in Salmonella isolates from Australian rangeland goats. The rate of detection of AMR was very low, some resistance to low-importance drugs was present in the Salmonella population, despite the absence of active selection pressure.

Characterization of Escherichia coli and Salmonella from Victoria, Australia, Dairy Farm Environments

Safe dairy food production starts at the farm level, with the presence of pathogens on farms potentially impacting the downstream food supply. Studies often commence with looking for pathogens in fecal material of farm animals, predominantly cows; however, pathogens may arise from other on-farm sources. In Australia, few studies have looked at the broader farm environment, particularly in relation to Escherichia coli and Salmonella. The present study characterized the genetic similarity of these pathogens from bovine, ovine, and caprine dairy farm environments and related this to the stx₁, stx₂, eae, or ehx virulence markers in E. coli and antibiotic resistance in Salmonella. E. coli isolates with indistinguishable genetic profiles and at least one of the virulence factors were found in multiple samples on the farms, although profiles were unique to each farm. E. coli O26 with stx₁ from one bovine farm had a different fingerprint type than all of the other E. coli O26 isolates, which lacked the Shiga toxin genes. They were from a separate bovine farm and were themselves closely related. No antibiotic resistance was detected among Salmonella isolates to the 17 antibiotics tested. Three Salmonella serotypes were identified: Orion, Infantis, and Zanzibar. The published PCR serotyping method used misidentified Salmonella Zanzibar as Salmonella Javiana, which was revealed after conventional antisera-based serotyping; this illustrates the need for caution when using PCR techniques for Salmonella serotype identification. Of the three serotypes, Salmonella Orion was most prevalent and was potentially resident on the farm. This article describes the previously unreported genetic diversity of potentially pathogenic E. coli and Salmonella serotypes from the farm environments of three dairy animal species in Victoria, Australia.

Investigations into Salmonella contamination in feed production chain in Karst rural areas of China

In order to understand the status of Salmonella contamination of feed production chain in Karst rural areas, southwest of China, a total of 1077 feed samples including animal feed materials and feed products were randomly collected from different sectors of feed chain covering feed mills, farms, and feed sales in nine regions of Karst rural areas between 2009 and 2012, to conduct Salmonella test. The different positive rates with Salmonella contamination were detected, the highest was 4.7 % in 2009, the lowest was 0.66 % in 2011, while 4.3 % in 2010, 2.8 % in 2012, respectively. Twelve types of feed including concentrate, complete, self-made, and feed ingredients were inspected. Salmonella contamination mainly concentrated on animal protein material such as meat meal, meat and bone meal, feather meal, blood meal, and fish meal. No Salmonella contamination was detected in feed yeast, microbial protein, rapeseed, and soybean meal. Salmonella contamination existed in each sector of feed production chain. This investigation provided a basic reference for feed production management and quality control in feed production chain in Karst rural areas of China.

Salmonella Presence in Mandibular, Mesenteric, and Subiliac Lymph Nodes Collected from Sheep and Goats in the United States

Even though often underappreciated in the United States, meat derived from goats and lambs is a valuable global commodity. Although extensive studies have been conducted examining pathogen prevalence in beef, pork, and poultry species, less research is available about pathogen presence in small ruminants. Understanding the presence of Salmonella in small ruminants can influence processing method improvements for these species to minimize food safety risks. The objective of this study was to establish the Salmonella presence in lymph nodes from sheep (n = 311) and goats (n =357) in the United States. Mandibular, mesenteric, and subiliac lymph nodes were collected from animals at abattoirs located in California, New Mexico, and Texas over a 14-month period. Lymph nodes were analyzed for Salmonella presence by using standard isolation methods, and presumptive isolates were confirmed with latex agglutination. Salmonella was detected in 3.15% of mandibular lymph nodes (n = 222), 5.83% of mesenteric lymph nodes (n = 223), and 7.62% of subiliac lymph nodes (n = 223). A total of 30 animals (13.39%) were found to have one or more Salmonella -positive lymph nodes. Our data indicate Salmonella is harbored within the lymph nodes of small ruminants. With this knowledge, further work can target strategies and interventions to minimize the risk associated with this pathogen during the processing of small ruminants.

The risk of carriage of Salmonella spp. and Listeria monocytogenes in food animals in dynamic populations

Salmonella spp. and Listeria monocytogenes are foodborne pathogens of global importance. We assessed their risks and associated factors in a highly dynamic population of animals. Animal and environmental samples were collected from dairy cattle, sheep, camel and chickens at either the farms or the abattoirs. The pathogens were detected using a combination of bacterial enrichment culture and real‐time polymerase chain reaction (PCR). Data on putative risk factors were collect and analysed for their significance of association with these pathogens.

Salmonella spp. were detected at higher proportions in sheep faeces and sheep carcasses in comparison to cattle faeces (odds ratio = 2.4 and 2.2, respectively). This pathogen was less common in milk or carcasses samples from cattle or chickens. Sheep and camel carcass samples were highly contaminated with Salmonella spp. Faecal samples from cattle had the most diverse serovars of Salmonella enterica including S. Newport, S. Haifa, S. Kedougou, S. Kentucky, S. Mbandaka and S. Goettingen. Exotic serovars in sheep included S. Eastbourne, S. Chester and S. Kottnus. Serovars that were shed in camel faeces included S. Newport, S. Bovismorbificans and S. Infantis. In all sampled populations, detection of Salmonella spp. was more likely during warmer months than cold months. Listeria monocytogenes was not common in the targeted populations and was detected at a rate of 2.4%, mainly from sheep carcasses. The study highlights the role of food animals as reservoirs of pathogens across boundaries since all feed are imported in that population from different parts of the world.

Detection of Salmonella spp. from chevon, mutton and its environment in retail meat shops in Anand city (Gujarat), India

AIM

The aim of this study was (i) To attempt isolation and identification of Salmonella species from samples. (ii) Serotyping of Salmonella isolates. (iii) Detection of virulence factor associated genes by polymerase chain reaction (PCR).

MATERIALS AND METHODS

A total of 284 samples comprised of chevon and mutton (112 samples each) as well as 60 samples (20 each of retail meat shops environment samples viz. Butchers' hands, knives and log swabs) were collected from the retail meat shops in and around Anand City under aseptic precautions. Rappaport-vassiliadis soy bean meal broth and tetrathionate broth was used for the enrichment of all the samples and inoculation was done on brilliant green agar and xylose lysine deoxycholate agar. This was followed by the confirmation of isolates using biochemical tests. For the serotyping, isolates were sent to the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli, Himachal Pradesh. Detection of virulence genes was performed by PCR technique using previously reported primer.

RESULT

Of 284 meats and retail meat shops environment samples, 13 (4.58%) samples were found positive for Salmonella. It was interesting to know that incidence of Salmonella was more in mutton (6.25%) than chevon (3.57%). In case of meat shop environmental samples 1 (5.00%) sample observed positive for Salmonella separately among the butchers' hands and knives swabs (Each of 20 samples) examined. Out of 13, eleven isolates detected as Salmonella Typhimurium, whereas only two isolates were detected as Salmonella Enteritidis. All Salmonella isolates possess invA and stn genes, whereas nine isolates had a presence of spvR gene while only five of the isolates revealed the presence of spvC gene as shown by in vitro detection of virulence genes by PCR.

CONCLUSION

Therefore, might be suggested that the good hygiene practices and effective control measures should be taken to encourage clean meat production with prolonged shelf-life.

Designing a risk communication strategy for health hazards posed by traditional slaughter of goats in Tshwane, South Africa

In African societies, traditional slaughter is linked to celebrations like weddings or births, as well as funerals and ancestor veneration. Participants in traditional slaughter of goats are at risk of exposure to hazards during slaughter, food preparation and consumption of goat meat. For risk mitigation strategies to be implemented, identification of the population at risk is required. This study is based on the premise that the demographic profile of people involved in traditional slaughter of goats is important for risk communication. Both structured and informal interviews were recorded and analysed using a thematic analysis. A total of 105 people were interviewed at taxi ranks in Tshwane, Gauteng. Of these, 48 were women and 57 men. The median age of women and men was 40.6 years and 44.3 years, respectively. The majority of respondents (61.9%, n = 65) interviewed were from the Gauteng Province. Sixty percent (n = 63) of respondents had a secondary education, whilst less than 4.81% (n = 5) of respondents had no formal education. This study demonstrated that interviewing commuters at taxi ranks gave access to a cross section of gender, age, language and origin. It was found that both genders were involved in traditional slaughter of goats. Risk communication strategies should thus target women as well as men. Communication strategies to mitigate the risks of traditional slaughter of goats should take into consideration the dynamic nature of demographic and cultural norms. In light of the wide demographic profile of the respondents, it was concluded that it should be possible to use taxi ranks for successful dissemination of food safety and occupational health risk mitigation messages.

Scientific Opinion on the public health hazards to be covered by inspection of meat from sheep and goats

A risk ranking process identified Toxoplasma gondii and pathogenic verocytotoxin-producing Escherichia coli (VTEC) as the most relevant biological hazards for meat inspection of sheep and goats. As these are not detected by traditional meat inspection, a meat safety assurance system using risk-based interventions was proposed. Further studies are required on T. gondii and pathogenic VTEC. If new information confirms these hazards as a high risk to public health from meat from sheep or goats, setting targets at carcass level should be considered. Other elements of the system are risk-categorisation of flocks/herds based on improved Food Chain Information (FCI), classification of abattoirs according to their capability to reduce faecal contamination, and use of improved process hygiene criteria. It is proposed to omit palpation and incision from post-mortem inspection in animals subjected to routine slaughter. For chemical hazards, dioxins and dioxin-like polychlorinated biphenyls were ranked as being of high potential concern. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account FCI, which should be expanded to reflect the extensive production systems used, and the ranking of chemical substances, which should be regularly updated and include new hazards. Control programmes across the food chain, national residue control plans, feed control and monitoring of environmental contaminants should be better integrated. Meat inspection is a valuable tool for surveillance and monitoring of animal health and welfare conditions. Omission of palpation and incision would reduce detection effectiveness for tuberculosis and fasciolosis at animal level. Surveillance of tuberculosis at the slaughterhouse in small ruminants should be improved and encouraged, as this is in practice the only surveillance system available. Extended use of FCI could compensate for some, but not all, the information on animal health and welfare lost if only visual post-mortem inspection is applied.

Animal contact as a source of human non-typhoidal salmonellosis

Non-typhoidal Salmonella represents an important human and animal pathogen world-wide. Most human salmonellosis cases are foodborne, but each year infections are also acquired through direct or indirect animal contact in homes, veterinary clinics, zoological gardens, farm environments or other public, professional or private settings. Clinically affected animals may exhibit a higher prevalence of shedding than apparently healthy animals, but both can shed Salmonella over long periods of time. In addition, environmental contamination and indirect transmission through contaminated food and water may complicate control efforts. The public health risk varies by animal species, age group, husbandry practice and health status, and certain human subpopulations are at a heightened risk of infection due to biological or behavioral risk factors. Some serotypes such as Salmonella Dublin are adapted to individual host species, while others, for instance Salmonella Typhimurium, readily infect a broad range of host species, but the potential implications for human health are currently unclear. Basic hygiene practices and the implementation of scientifically based management strategies can efficiently mitigate the risks associated with animal contacts. However, the general public is frequently unaware of the specific disease risks involved, and high-risk behaviors are common. Here we describe the epidemiology and serotype distribution of Salmonella in a variety of host species. In addition, we review our current understanding of the public health risks associated with different types of contacts between humans and animals in public, professional or private settings, and, where appropriate, discuss potential risk mitigation strategies.