Philippe Fravalo

Université de Montréal | UdeM · Department of Pathology and Microbiology

Campylobacter jejuni is the most prevalent bacterial foodborne pathogen in humans. Given the wide genetic diversity of C. jejuni strains found in poultry production, a better understanding of the relationships between these strains within chickens could lead to better control of this pathogen on farms. In this study, 14-day old broiler chickens wer...

Clostridium botulinum is the main causative agent of botulism, a neurological disease encountered in humans as well as animals. Nine types of botulinum neurotoxins (BoNTs) have been described so far. Amongst these “toxinotypes,” the A, the B and E are the most frequently encountered in humans while the C, D, C/D and D/C are mostly affecting domesti...

The microorganisms found on fresh, raw meat cuts at a slaughterhouse can influence the meat’s safety and spoilage patterns along further stages of processing. However, little is known about the general microbial ecology of the production environment of slaughterhouses. We used 16s rRNA sequencing and diversity analysis to characterize the microbiot...

Bacterial contamination during meat processing is a concern for both food safety and for the shelf life of pork meat products. The gut microbiota of meat-producing animals is one of the most important sources of surface contamination of processed carcasses. This microbiota is recognized to vary between pigs from different farms and could thus be re...

Swine are an important food source worldwide and producers may not always be aware of the variety of the pathogens infecting their herds, particularly viruses. In this study, 12 enteric viruses were monitored in a total of 181 diarrheic and healthy piglets; namely porcine astrovirus groups 1 to 5 (poAstV1-5), rotavirus A and C (RVA-RVC), caliciviru...

Background Avian necrotic enteritis (NE) caused by Clostridium perfringens is a disease with a major economic impact, generating losses estimated to 6 billion of dollars annually for the poultry industry worldwide. The incidence of the disease is particularly on the rise in broiler chicken flocks eliminating the preventive use of antibiotics. To da...

The role of the accompanying microbiota in the presence of Listeria monocytogenes on meat processing surfaces is not yet understood, especially in industrial production conditions. In this study, 300 conveyor belt samples from the cutting room of a swine slaughterhouse were collected during production. The samples were subjected to the detection of...

Recycled manure solids (RMS) bedding is an alternative bedding option that is growing in popularity on Canadian dairy farms. However, the microbiological characteristics and production of RMS bedding are poorly documented under on-farm conditions in eastern Canada. This bedding could support the presence of pathogens and could have an effect on cow...

The intestinal microbiota plays several important roles in pig health and growth. The aim of the current study was to characterize the changes in the fecal microbiota diversity and composition of weaned piglets following an oral challenge with an ETEC: F4 strain and/or a treatment with colistin sulfate (CS). Twenty-eight piglets were used in this e...

Listeria monocytogenes (L. monocytogenes) is often associated with processed food as it can form biofilms that represent a source of contamination at all stages of the manufacturing chain. The control and prevention of biofilms in food-processing plants are of utmost importance. This study explores the efficacy of prospect molecules for counteracti...

The ever-increasing problem of antibiotic resistance makes routine use of antibiotics in animal production no longer considered as a reasonable and viable practice. The Chicken Farmers of Canada have developed and are implementing an Antimicrobial Use Reduction Strategy, which has the ultimate goal of eliminating the preventive use of medically imp...

Tail-biting (TB) in pigs is a serious behavioral disorder. It is an important challenge in swine production as it impacts animal welfare and health and the economics and safety of the pork meat supply chain. To prevent TB, approaches including enrichment material and tail docking are proposed but none are optimal. Nutrition appears to be an importa...

The porcine enteric microbiota is currently extensively studied, taking advantage of developments in high-throughput sequencing technologies. However, the viral part of the microbiota, the virome, is being lightly explored, and the impact of the pretreatments used before sequencing the viruses is barely considered. In this study, the impacts of fil...

Yersinia enterocolotica is an important causative agent of diarrheal illness. A systematic review and meta-analysis of case-control studies were performed to determine the main risk factors associated with sporadic Y. enterocolitica infections. Suitable scientific articles published between 1987 and 2017 were identified through a systematic literat...

Salmonella is a foodborne pathogen commonly associated with poultry products. The aims of this work were to (i) estimate the impact of critical steps of the slaughter process on Salmonella detection from broiler chicken carcasses in two commercial poultry slaughter plants in Quebec, Canada; (ii) investigate the presence of Salmonella in the slaught...

Listeria monocytogenes is the etiological agent of listeriosis, a major foodborne disease and an important public health concern. Contamination of meat with L. monocytogenes occurs frequently at the slaughterhouse. Our aims were; 1) to investigate the distribution of L. monocytogenes in the processing areas of four swine slaughterhouses; 2) to desc...

Non-typhoidal Salmonella is an important causative agent of diarrheal illness worldwide. A systematic review and meta-analysis of case-control studies were performed to determine the main risk factors associated with sporadic salmonellosis. Suitable scientific articles published up to 2017 were identified through a systematic literature search and...

Campylobacter spp. is an important causative agent of diarrheal illness worldwide. The disease is frequently associated with foodborne transmission, but other routes of exposure are increasingly recognized. A systematic review and meta-analysis of case-control studies were performed to determine the main risk factors associated with sporadic campyl...

The aim of the study was to investigate fecal microbial transplantation (FMT) as a novel strategy to modulate the postnatal development of porcine immune system and the establishment of the intestinal microbiota in newborn piglets. Ten litters were used for the experiment. At birth, four piglets were identified in each litter and randomly assigned...

The Canadian Food Inspection Agency is developing an Establishment-based Risk Assessment model for Hatcheries to allocate inspection resources according to the food safety risk associated with each hatchery falling under its jurisdiction. In a previous study, 29 factors contributing to the food safety risk of hatcheries were identified and grouped...

Background: Tail-biting (TB) is a serious behavioral disorder in pigs. It is defined as a pig chewing the tail of another pig. It is an important challenge in swine production as it impacts the animal welfare, its health and the economics and safety of the pork meat supply chain. Some treatments have been proposed but have not proven optimal. Nutri...

In broiler chicken production, microbial populations on the eggshell surface following oviposition are still poorly characterized, though they may significantly impact both poultry and public health. The aim of this study was to describe the microbiota of both broiler breeder hens’ feces and the surface of their eggs to assess the contribution of t...

With increased interest in source attribution of foodborne pathogens, there is a need to sort and assess the applicability of currently available methods. Herewith we reviewed the most frequently applied methods for source attribution of foodborne diseases, discussing their main strengths and weaknesses to be considered when choosing the most appro...

Towards the continuous improvement of its inspection system, the Canadian Food Inspection Agency (CFIA) is developing an Establishment‐based Risk Assessment model for Hatcheries to allocate inspection resources based on the food safety risk associated with the Canadian hatcheries falling under its jurisdiction. The objectives of the current study w...

Objective To evaluate whether pig farms interconnected within the same cooperative share similar Salmonella contamination patterns. Setting Ten finishing pig farms within a 100 km radius of a common slaughterhouse were selected. Their inclusion was based on their association to the same cooperative and the sharing of common resources: piglets, fee...

Objectives: This study investigated the prevalence of Escherichia coli (E. coli) colistin resistance and mcr-1 and mcr-2 genes among extended-spectrum β-lactamase (ESBL)/AmpC-producing E. coli isolates recovered from chicken feces in Canada (Quebec), Senegal and Vietnam, and evaluated the susceptibility pattern of the colistin-resistant E. coli is...

[This corrects the article DOI: 10.1371/journal.pone.0212946.].

Campylobacter jejuni is a zoonotic agent responsible for the foodborne gastroenteritis campylobacteriosis. Control of C. jejuni load in the poultry primary production is recognized as an avenue to reduce human exposure to the pathogen. As for now, no commercially applicable control methods exist at the farm. Several studies tested egg yolk powders,...

The bar represents the mean count (n = 8) of still cultivable bacteria in the presence of complement (Test) or inactivated complement (Control) in presence of EYP containing the highest concentrations of antibodies against OMP and KB. (DOCX)

Background The aim of this study was to characterize the genomes of 30 Listeria monocytogenes isolates collected at a pig slaughterhouse to determine the molecular basis for their persistence. Results Comparison of the 30 L. monocytogenes genomes showed that successive isolates (i.e., persistent types) recovered from thew sampling site could be li...

The bacterial short pre-enrichment culture step is important for the proper detection and isolation of Salmonella spp. from pig feces. Using metagenomics, we showed that pre-enrichment of Salmonella was favored not only by inhibiting the growth of competing bacteria but also by increasing its fitness.

Aim Observe the transfer of the digestive microbiota from sow to piglet, describe the impact of the sow's Salmonella shedding on this transfer and identify transferred populations that could be associated with the future Salmonella status of the piglets. Methods and results Salmonella shedding status of 19 sows was determined at the beginning and...

Comparaison génétique de Campylobacter coli issus de porcs et de volailles avec des isolats issus de campylobactérioses humaines. 133 isolats de Campylobacter coli provenant de la Bretagne et isolés en 2003 ont été génotypés par RFLP/PFGE. Ils proviennent de la filière porc (65), de la filière volaille (56) et de campylobactérioses humaines (12). L...

The importance of Salmonella and Campylobacter as foodborne pathogens is well recognized worldwide. Poultry and poultry products are commonly considered as the major vehicles of Salmonella and Campylobacter infection in humans. The aim of this study was to investigate the hygienic status of poultry facilities and determine the prevalence of Salmone...

Camels (Camelus dromedarius) are known to harbor multidrug resistant Gram-negative bacteria and to be involved in the transmission of various microorganisms to humans. Data on the occurrence of colistin resistant Escherichia coli as well as mobilized colistin resistance (mcr) genes in camels are lacking. We investigated the presence of colistin res...

Clostridium perfringens ranks among the three most frequent bacterial pathogens causing human foodborne diseases in Canada, and poultry meat products are identified as a source of infection for humans. The objective of the current study was to estimate the proportion of broiler chicken flocks, carcasses and various environmental samples from critic...

Background Campylobacter jejuni is a major cause of foodborne disease having chickens as an important reservoir. Its control at the farm would lower the contamination of the final products and therefore also lower the risk of transmission to humans. At the farm, C. jejuni is rarely found in chickens before they reach 2 weeks of age. Past studies ha...

Pork meat is estimated to be responsible for 10–20% of human salmonellosis cases in Europe. Control strategies at the farm could reduce contamination at the slaughterhouse. One of the targeted sectors of production is maternity, where sows could be Salmonella reservoirs. The aim of this study was to assess the dynamics of shedding of Salmonella in...

Campylobacter jejuni is the leading cause of campylobacteriosis in the developed world. Although most cases are caused by consumption of contaminated meat, a significant proportion is linked to ingestion of contaminated water. The differences between C. jejuni strains originating from food products and those isolated from water are poorly understoo...

Time lapse phase-contrast microscopy was performed across 24 h with 16 frames per seconds to show Listeria monocytogenes biofilm grown under BHI (the top section) and BHI/10 (The bottom section).

Time lapse phase-contrast microscopy was performed across 18 h with 16 frames per seconds to show Listeria monocytogenes biofilm grown under BHI (in the top section) and BHI/10 (in the bottom section) supplemented with DNase I at the final concentration of 100 μg/ml.

Time lapse phase-contrast microscopy was performed across 24 h with 16 frames per seconds to show Listeria monocytogenes biofilm grown under BHI medium in microfluidic system. The video shows filaments detached from the chamber surface under the flow effect.

Time lapse phase-contrast microscopy was performed across 18 h with 16 frames per seconds to show Listeria monocytogenes biofilm grown under BHI/10 without DNase I treatment (in the top section) and BHI/10 (in the bottom section) supplemented with DNase I at the final concentration of 100 μg/ml.

Biofilm formation by the pathogen Listeria monocytogenes is a major concern in food industries. The aim of this work was to elucidate the effect of nutrient limitation on both biofilm architecture and on the viability of the bacteria in microfluidic growth conditions. Biofilm formation by two L. monocytogenes strains was performed in a rich medium...

The introduction of Listeria monocytogenes into the food production chain is a concern, with numerous grouped cases of listeriosis associated with milk-derived or pork-derived products have been documented. Management of this zoonotic pathogen considers all strains as an equal risk. Recently, a new perspective for characterisation of strain virulen...

Faced with ever-increasing demand, the industrial production of food animals is under pressure to increase its production. In order to keep productivity, quality, and safety standards up while reducing the use of antibiotics, farmers are seeking new feed additives. In chicken production, one of these additives is selenium. This element is expected...

Importance: Using Rotaviruses and Astroviruses as markers of enteric contamination in a swine network has revealed the potential role of abattoirs and livestock transporters as reservoir and vectors of enteric pathogens. Results from this study highlight the importance of tightening biosecurity measures. For instance, implementing sanitary vacancy...

Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatit...

Aims: The object of this study was to determine the impact of only modifying the processing and/or particle size of pig feed on Salmonella shedding and faecal microbiota. Methods and results: Pigs were fed a diet that varied only by their processing (pellet or mash) and their particle size (500, 750 or 1250 μm) for 21 days. Salmonella detection...

Feed characteristics may influence the bacterial community composition and metabolic activities in the pig gastrointestinal tract, known to be associated with positive effects on the gut. Use of mash feed is associated with reduced excretion, but little is known of its effect on the population or of the mechanism of action. Our objectives were to a...

Feed characteristics may influence the bacterial community composition and metabolic activities in the pig gastrointestinal tract, known to be associated with positive effects on the gut. Use of mash feed is associated with reduced Salmonella excretion, but little is known of its effect on the Escherichia coli population or of the mechanism of acti...

Campylobacter jejuni cause gastroenteritis in humans. The main transmission vector is the consumption or handling of contaminated chicken meat, since chicken can be colonized asymptomatically by C. jejuni. However, water has been implicated as the transmission vector in a few outbreaks. One possibility is the contamination of water effluent by C. j...

In 2011 and 2012, trials consisting of experimental plots were carried out to evaluate the presence of pathogenic (Listeria monocytogenes, Salmonella) and prevalence of indicator (Escherichia coli) microorganisms in broccoli fertilized with liquid hog manure or mineral fertilizers and irrigated zero, one, or two times with E. Coli-contaminated wate...

Campylobacter jejuni is an important zoonotic foodborne pathogen causing acute gastroenteritis in humans. Chickens are often colonized at very high numbers by C. jejuni, up to 109 CFU per gram of caecal content, with no detrimental effects on their health. Farm control strategies are being developed to lower the C. jejuni contamination of chicken f...

This study describes and measures the impact of different compositions and finishes of stainless steel used in equipment in the meat industry on the transfer of natural flora and selected pathogens from artificially contaminated pork skin. It is known that the adhesion to surfaces of Listeria monocytogenes and Salmonella, 2 pathogens frequently fou...