Choice of fumigation sheets for use in the tropics (ODNRI Bulletin No. 27)

A successful fumigation requires that an insecticidal concentration of the fumigant is maintained within the fumigation chamber during the exposure period. The demand for fumigation sheets is generally too low for manufacturers to formulate plastic sheets specifically for this purpose. Therefore it is necessary to select the most suitable material from whatever is available. This bulletin gives guidelines to assist in making the right choice

Fumigation with phosphine under gas-proof sheets (ODNRI Bulletin No. 26)

Although fumigation with phosphine is a simple technique, results, in terms of insect mortality, are often unsatisfactory. This is because complete insect control can only be achieved if an insecticidal concentration of phosphine is maintained for a sufficient length of time. Where multiple fumigations with phosphine have failed to meet these criteria insect resistance to phosphine has become established. This bulletin describes the formulations, equipment, application techniques and safety considerations required to achieve satisfactory fumigation results

Vaccination to control Salmonella shedding and improve growth in pigs

A clinical field trial was performed to determine the effectiveness of an autogenous Salmonella Typhimurium bacterin compared to a commercial live S. choleraesuis vaccine in pigs. The association between Salmonella shedding and weight gain was also investigated. Nine cohorts of weaned pigs were randomly assigned to one of three treatment groups (injection with S. Typhimurium bacteria, vaccination via water with S. Choleraesuis vaccine, or a control group receiving no vaccine). In each cohort, the average daily gain was calculated for a selected pen throughout the production stage. Fecal samples were collected bi-weekly and cultured. The pigs vaccinated for S. Choleraesuis were more likely to shed Salmonella compared to pigs vaccinated with S. Typhimurium bacterin and the chance of Salmonella shedding in the both vaccinated groups was higher than in the control group. The pigs from pens with a higher Salmonella recovery rate experienced slower growth compared to pigs from pens where Salmonella was not isolated. This latter finding indicates that there might be an economic incentive for producers to try to control endemic salmonellosis if effective programs could be developed

Critical review of interventions against Salmonella in the farm-to-processing pork production continuum

The purpose of this study was to identify, evaluate and summarize the available scientific literature on the effectiveness of interventions against Salmonella, in the farm-to-processing pork production continuum, following the principles of systematic review methodology

Single nucleotide polymorphisms (SNPs) in genes related to innate immune response against Salmonella in nursery pigs

The objective of this study was to investigate the association of single nucleotide polymorphisms (SNPs) in innate immune response genes with Salmonella shedding in nursery pigs. One hundred and sixty eight pigs on seven farrow-to- finish farms and one farrow-feeder operation were included in the study. On each farm, 21 pigs were selected from seven sows at weaning. Fecal samples were collected from selected pigs and cultured for Salmonella, and the isolates were serotyped. DNA was extracted from liver samples and used to genotype pigs for single nucleotide polymorphisms (SNPs) in 21 different innate immune response genes. In total, 15 (9.3%) pigs tested positive for Salmonella; the isolates from six pigs from four different litters on one farm were serotyped as Salmonella Infantis and from nine pigs from six different litters on another farm as Salmonella Worthington. SNP analysis showed an association of Salmonella shedding with a SNP in the genes encoding mannan-binding lectin (MBL)-associated serine protease-2 (MASP-2) and Toll-like receptor-1 (TLR-1) (P \u3c 0.05). These findings suggest that Salmonella shedding in pigs is controlled by genetic elements and these genetic variants could possibly be used to breed pigs that are more resistant to Salmonella colonization and Salmonella shedding

Molecular epidemiology of Salmonella Typhimurium DT104 on Ontario swine farms

This study was conducted to investigate the diversity in antimicrobial resistance (AMR), plasmid profiling, and pulsed field gel electrophoresis (PFGE) of 81 S. Typhimurium and S. Typhimurium var Copenhagen DT 104 strains recovered from pig and environmental fecal samples on swine farms in Ontario. No resistance was observed to amoxiclllin and clavulanic acid, apramycin, carbadox, cephalothin, ceftnaxone, ceftiofur, cefoxitin, cipronoxacin, nalidixic acid, trimethoprim, and tobramycin. However, the isolates exhibited resistance against 4 to 10 antimicrobials with most frequent resistance to sulfonamides (Su), ampicillin (A), streptomycin (S), spectinomycm (Sp), chloramphenicol (C), tetracycline (T), and norfemcol (F)

Molecular epidemiology of Giardia duodenalis and Cryptosporidium spp on swine farms in Ontario, Canada

A subset of swine farms in Ontario, Canada have been monitored for Cryptosporidium and Giardia. Fecal samples were collected from different stages of production as well as from manure pits. G. duodenalis cysts and Cryptosporidium spp. oocysts were detected in the manure samples using immunofluorescence microscopy. A nested PCR and sequencing method was performed to determine the genotypes. A mixed multivariable method was used to compare the prevalence of Cryptosporidium and Giardia in samples from different sources

Monitoring of Salmonella, Campylobacter, Yersinia enterocolitica, E. coli 0157, and Listeria monocytogenes on a subset of Canadian swine farms

The objective of the present study was to investigate the occurrence of major bacterial foodborne pathogens in swine on a subset of Ontario swine farms between 2005 and 2007 In total, 359 samples from manure storage tanks and fresh pooled feces obtained from finisher pigs, sows, and weanlings were collected and tested Campylobacter, Salmonella, Y. enterocolitica, E coli 0157 and L monocytogenes were isolated from 36.5%, 31.5%, 5.8%, 3 3%, and 33% of samples, respectively. All E. coli O157 isolates were tested but none were determined to be E. coli O157:H7 Salmonella and Campylobacter were more likely to be detected from stored manure rather than fresh fecal samples. Y. enterocolitica tended to be detected more commonly from fresh samples than from manure pits

Using multinomial logistic regression method to investigate the farm-level antimicrobial resistance in Salmonella in swine

The objective of this study was to investigate the farm-level risk factors associated with antimicrobial resistance of Salmonella spp. on Ontario swine farms. Fecal samples were collected on 80 swine farms and tested for Salmonella and antimicrobial resistance. The farms were classified into three groups including Salmonella-negative farms (Group 1), Salmonella-positive farms without antimicrobial resistance (Group 2), and Salmonella-positive farms with antimicrobial resistance (Group 3). No risk factor was associated with the Group 2 classification