Dynamic of Campylobacter infection within pig farms from sows to fattening pigs

This work aimed at (i) describing Campylobacter excretion by conventional pigs in field conditions from sows to fattening pigs, and (ii) assessing the role of the environment as a source of pig contamination. Five sows and six piglets per sow were individually followed in two farrow-to-finish farms

Efficient waterlines cleaning protocols in post-weaning rooms: a new way to reduce antibiotic consumption?

In this study, we have chosen a sensitive period, the weaning period, to evaluate in pig farms the effects of different mechanical and chemical waterlines cleaning protocols similar to those used in poultry farms. The experiment has been set up during the down period in two post-weaning rooms with two different protocols. They combined the mechanical action of draining, one detergent (either alkaline or enzymatic), another draining state, and finally one acid used at an antibacterial concentration. To follow the bacteriological quality of water during protocols, we have counted the total flora at 22°C and 37°C in water. Before and after the experiment, cotton swabs were applied into the pipes to evaluate the biofilm. Bacterial concentration in water increased along the pipelines: total flora was higher at watering place than at the entry of the building. Both protocols combining mechanical and chemical procedures reduced total flora, improved water quality and cleanliness of pipes. Our results show that waterlines cleaning protocols used in poultry farms can be transferred in post-weaning rooms. By reducing water’s total flora and the formation of biofilms, they could be part of the health prevention measures for troubles which are linked to a poor water quality

Modelling the prevalence of Salmonella carrier pigs at slaughtering age: influence of management systems and of the Salmonella status of replacement gilts

To reduce Salmonella contamination of pork food cham at the farm level, control actions can aim at preventmg the introduction of the bactena into herds or/and at preventing the in-herd transmission. Our aim is to estimate the influence of (i) the decontamination efficiency and (ii) the Salmonella status of replacement gilts on the prevalence of carrier pigs at slaughtering age. We developed a stochastic mathematical model to simulate the pig population dynamics and the Salmonella transmiss1on withrn a farrow-to-finish herd. Results show a different prevalence of carnage in groups of delivered pigs according to the scenarios tested

Salmonella control within the pyramidal structured network of pigs\u27 movements in France

Due to economical and public health consequences, control of Salmonella spread within pig herds is a major concern for the swine industry. A better understanding of the links between herds as well as between herds and slaughterhouses within a production stmcture is then needed to assess the effect of possible control measures at this level. In the French pork production chain, herds have specific links between them: some herds being animals suppliers for others. This organization induces a specific complex network in which the contacts between herds are hierarchized, dynamic and directed. We present here a modelling approach to assess the effect of control measure implementation on the Salmonella spread within the pyramidal structure of French pork production chain, coupled with the within-herd dynamics to represent the spread of Salmonella. Firstly, the susceptibility of the pyramidal organization to an external infection is tested. The number of infected herds at the end of the simulation is highly variable according to the initial infected herd (type of herd, level of the pyramid). Secondly, we assess the effect of a control measure implementation on the seroprevalence in groups of slaughter pigs. This measure, which consists in restricting animals\u27 purchases according to the infectious status of herds combined with a reduction of within herd transmission of Salmonella, leads to decrease the number of highly contaminated herds. This modeling approach allows us to investigate the impact of control measures both at the within and the between-herds level

Effect of antimicrobial use on the resistance of Escherichia coli in faecal flora of pigs

The antimicrobial use in veterinary medicine is of concern because of possible transmisston of resistant bacteria to humans. However the relation between use and occurrence of resistance is poorly documented in the field. Sixteen farrow-to-fimsh herds were selected and classified on the frequency of antimicrobial administrations (low (LU), medium (MU) and high (HU) users). lndtcative Eschenchia coli strains were tsolated from faeces of sows (5 per herd) and young pigs (3 per sow) at several ttmes during animals\u27 hfe and tested for reststance to amoxicillin, gentamicin, trimethoprim-sulfamids and tetracyclin. The percentages of resistant strams were compared between herd groups

Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies

Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could be used more effectively if they benefited from the scientific and technical resources currently available for more common breeds. Last but not least, public policies need to enable improved information concerning the genetic resources and breeding tools available for the agroecological management of livestock production systems, and facilitate its assimilation by farmers and farm technicians

The fecal microbiota of piglets during weaning transition and its association with piglet growth across various farm environments

This study describes the fecal microbiota from piglets reared in different living environments during the weaning transition, and presents the characteristics of microbiota associated with good growth of piglets after weaning. Fecal samples were collected pre- (d26) and post-weaning (d35) from 288 male piglets in 16 conventional indoor commercial farms located in the West of France. The changes one week after weaning on the most abundant microbial families was roughly the same in all farms: alpha diversity increased, the relative abundance of Bacteroidaceae (-61%), Christensenellaceae (-35%), Enterobacteriaceae (-42%), and Clostridiaceae (-32%) decreased, while the relative abundance of Prevotellaceae (+143%) and Lachnospiraceae (+21%) increased. Among all the collected samples, four enterotypes that were ubiquitous in all farms were identified. They could be discriminated by their respective relative abundances of Prevotella, Faecalibacterium, Roseburia, and Lachnospira, and likely corresponded to a gradual maturational shift from pre- to post-weaning microbiota. The rearing environment influenced the frequency of enterotypes, as well as the relative abundance of 6 families at d26 (including Christensenellaceae and Lactobacillaceae), and of 21 families at d35. In all farms, piglets showing the highest relative growth rate during the first three weeks after weaning, which were characterized as more robust, had a higher relative abundance of Bacteroidetes, a lower relative abundance of Proteobacteria, and showed a greater increase in Prevotella, Coprococcus, and Lachnospira in the post-weaning period. This study revealed the presence of ubiquitous enterotypes among the farms of this study, reflecting maturational stages of microbiota from a young suckling to an older cereal-eating profile. Despite significant variation in the microbial profile between farms, piglets whose growth after weaning was less disrupted were, those who had reached the more mature phenotype characterized by Prevotella the fastest

Potential alternatives to antimicrobials in pig production based on perceived effectiveness, feasibility and return on investment

Based on a questionnaire returned by 111 pig health experts from six European countries a list of potential alternatives to antimicrobials was ranked. These althernatives provide input for further studies to find strategies to reduce the widely discussed use of antimicrobials and the potential risk from antimicrobial resistance

Guidance on the Selection of Appropriate Indicators for Quantification of Antimicrobial Usage in Humans and Animals

An increasing variety of indicators of antimicrobial usage has become available in human and veterinary medicine, with no consensus on the most appropriate indicators to be used. The objective of this review is therefore to provide guidance on the selection of indicators, intended for those aiming to quantify antimicrobial usage based on sales, deliveries or reimbursement data. Depending on the study objective, different requirements apply to antimicrobial usage quantification in terms of resolution, comprehensiveness, stability over time, ability to assess exposure and comparability. If the aim is to monitor antimicrobial usage trends, it is crucial to use a robust quantification system that allows stability over time in terms of required data and provided output; to compare usage between different species or countries, comparability must be ensured between the different populations. If data are used for benchmarking, the system comprehensiveness is particularly crucial, while data collected to study the association between usage and resistance should express the exposure level and duration as a measurement of the exerted selection pressure. Antimicrobial usage is generally described as the number of technical units consumed normalized by the population at risk of being treated in a defined period. The technical units vary from number of packages to number of individuals treated daily by adding different levels of complexity such as daily dose or weight at treatment. These technical units are then related to a description of the population at risk, based either on biomass or number of individuals. Conventions and assumptions are needed for all of these calculation steps. However, there is a clear lack of standardization, resulting in poor transparency and comparability. By combining study requirements with available approaches to quantify antimicrobial usage, we provide suggestions on the most appropriate indicators and data sources to be used for a given study objective

Comparison of sequential cytomegalovirus isolates in a patient with lymphoma and failing antiviral therapy

BACKGROUND: Long-term anti-cytomegalovirus (CMV) treatments in immunocompromised patients are hampered by resistance to antiviral drugs. Longitudinal changes in the resistance genotype may depend on changes in selective pressure and the complexity of CMV isolates. OBJECTIVE: To evaluate longitudinal changes in the CMV resistance genotype and phenotype along with strain-specific variability in a patient with non-Hodgkin\u27s lymphoma in whom successive anti-CMV treatments failed. STUDY DESIGN: The resistance phenotype and genotype of seven CMV isolates collected from one patient during a 2-year follow-up period were retrospectively analysed. In parallel, we used glycoprotein B (gB) genotyping, and a- and UL10-13-sequence analysis to study CMV interstrain variability. RESULTS: The patient was infected by at least three CMV strains plus variants of the parental strains. Resistance to ganciclovir, cidofovir and foscarnet was successively detected during the follow-up period. UL97 protein kinase changes responsible for resistance to ganciclovir were initially detected at residues 591 and 592, and then at position 594. Decreased sensitivity to foscarnet coincided with the appearance of amino acid substitution N495K in DNA polymerase, whereas cross-resistance to ganciclovir and cidofovir was due to the L501I substitution. CONCLUSIONS: The CMV isolates obtained from our patient were complex mixtures of strains. Changes in resistance genotypes depended on resistance selective pressure and were not linked to interstrain variation