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Pathogen amplification and dissemination into the environment through manure spreading on agriculture land is facilitated by the epidemic spread of 'Salmonella enterica' serovar Newport in dairy cattle. A study was conducted to uncover the survival characteristics of 'Salmonella enterica' serovar Newport in manure and manure-amended soils where the pathogen may be amplified.

Salmonella spp. are environmentally persistent pathogens that have served as one of the important models for understanding how bacteria adapt to stressful conditions. However, it remains poorly understood how they survive extreme conditions encountered outside their hosts. Here we show that the rdar morphotype, a multicellular phenotype characterized by fimbria- and cellulose-mediated colony pattern formation, enhances the resistance of Salmonella to desiccation. When colonies were stored on plastic for several months in the absence of exogenous nutrients, survival of wild-type cells was increased compared to mutants deficient in fimbriae and/or cellulose production. Differences between strains were further highlighted upon exposure to sodium hypochlorite, as cellulose-deficient strains were 1,000-fold more susceptible. Measurements of gene expression using luciferase reporters indicated that production of thin aggregative fimbriae (Tafi) may initiate formation of colony surface patterns characteristic of the rdar morphotype. We hypothesize that Taft play a role in the organization of different components of the extracellular matrix. Conservation of the rdar morphotype among pathogenic S. enterica isolates and the survival advantages that it provides collectively suggest that this phenotype could play a role in the transmission of Salmonella between hosts.

Research has been conducted on salmonella infection in wild-living birds in Norway. The authors summarize the records of Salmonella detection in wild birds and compare the isolates via the use of plasmid profile analysis and phage typing.

Researchers used conventional serotyping and the ribosomal spacer-heteroduplex polymorphism method to identify more than 40 different Salmonella serotypes in the Tech River watershed on the south coast of France. Some serotypes were only found after storms and could represent contamination from farms.

A method, called the agar underlay method, for culture and recovery of sublethally heat-injured bacteria has been developed. The method has advantages vs other injury recovery methods. Unlike agar overlay methods, the underlay method allows the typical selective-medium colony morphology to develop for food-borne pathogens that are heat-injured, for instance Escherichia coli O157:H7 and Salmonellla typhimurium. Colonies can be more easily picked for further characterization.

A comparative study between the performance of commercial PCR-based Salmonella enterica detection methods and the culture-based methods in spiked and naturally contaminated samples of feed mill scrapings (FMS), palm kernel meal (PKM), pelleted feed (PF), rape seed meal (RSM), soybean meal (SM), and wheat grain (WG) is presented. A statistical model that describes the detection probability when different levels (CFU) of Salmonella contamination are present in feed materials is also presented.

The levels of two key pathogens, Salmonella and Campylobacter, are assessed along with the indicator organism Escherichia coli in aerosols within and outside poultry sheds. The studies have shown that the public health risk from these organisms in poultry environments via the aerosol pathway is very minimal.

Sulfonamide-resistant Escherichia coli and Salmonella isolates from pigs and chickens in Ontario and Quebec are screened for sul1, sul2 and sul3 by PCR. Each sul gene is distributed differently across populations, with a significant difference between distribution in commensal Escherichia coli and Salmonella isolates and sul3 restricted mainly to porcine Escherichia coli isolates.

The plasmid component of the genome of Salmonella Kentucky CVM29188, a multidrug-resistant strain that is isolated from a chicken meat sample with resistance to streptomycin, tetracycline, ampicillin and ceftiofur, is described. A combination of in silico and in vivo approaches, including comparative plasmid transfer, and PCR-based plasmid screenings, is used for providing insights into the genetic basis for multidrug resistance phenotypes of the isolate that provide new clues about virulence evolution and host adaptation in the Salmonella serovar.

Several groups of beetles and their larvae are artificially contaminated with a mixture of Salmonella enterica serovar Paratyphi B variant Java and three C. jejuni strains and are kept for different time intervals before they are fed to individually housed chicks. The results revealed that Salmonella and Campylobacter might be transmitted via beetles or their larvae to flocks in successive rearing cycles and need an intensive control program to eliminate insects from broiler houses.

A small focused library of brominated furanones is synthesized to test their activity against Salmonella enterica serovar typhimurium biofilm formation. The results demonstrated the potential use of brominated furanones in the prevention of biofilm formation by Salmonella serovar typhimurium.

The aerobic plate counts (APC) and the prevalences and loads of Salmonella and Escherichia coli 0157:H7 is measured to examine the hide and carcass hygiene of cull cattle at slaughter in four geographically distant regions of the United States. The pathogen prevalence on hides and carcasses is not affected by the season, however postintervention carcass contamination is significantly reduced due to the use of one or more intervention processes employed at each of the four processing plants examined.

A study was conducted to determine the prevalence of protozoa on spinach and lettuce and to examine their interactions with Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes. The presence of protozoa found on leafy vegetables and their sequestration of enteric bacteria in vesicles revealed that protozoa might play critical role in the ecology of human pathogens on produce for food safety and public health.

Research has been conducted on lytic bacteriophages. The authors report that these bacteriophages experimentally contaminated with Campylobacter and Salmonella have been applied to chicken skin, and that after the application the bacteriophages have shown the increase in titer, and have reduced the pathogen numbers.

Research has been conducted on Salmonella enterica infection source. The authors report that abattoir holding pens can serve as infection source, and identify a potential control point for Salmonella contamination in the preharvest pork production chain.