Poultry-Associated Salmonella enterica subsp. enterica Serovar 4,12:d:− Reveals High Clonality and a Distinct Pathogenicity Gene Repertoire

Abstract

A European baseline survey during the years 2005 and 2006 has revealed that the monophasic Salmonella enterica subsp. enterica serovar 4,12:d:؊ was, with a prevalence of 23.6%, the most frequently isolated serovar in German broiler flocks. In Denmark and the United Kingdom, its serovar prevalences were 15.15% and 2.8%, respectively. Although poultry is a major source of human salmonellosis, serovar 4,12:d:؊ is rarely isolated in humans (approximately 0.09% per year). Molecular typing studies using pulsed-field gel electrophoresis and DNA microarray analysis show that the serovar is highly clonal and lacks genes with known contributions to pathogenicity. In contrast to other poultry-associated serovars, all strains were susceptible to 17 antimicrobial agents tested and did not encode any resistance determinant. Furthermore, serovar 4,12:d:؊ lacked the genes involved in galactonate metabolism and in the glycolysis and glyconeogenesis important for energy production in the cells. The conclusion of the study is that serovar 4,12:d:؊ seems to be primarily adapted to broilers and therefore causes only rare infections in humans.

Infection of chickens with antimicrobial-resistantSalmonella entericaTyphimurium DT193 and monophasicSalmonellaTyphimurium-like variants: an emerging risk to the poultry industry?

“…All of the isolates in this study display a full range of virulence-associated genes and normal growth characteristics (Crayford, Humphrey, & Wigley, unpublished data), suggesting they are capable of causing gastrointestinal disease in humans. This differs from serotype 4,12:d, a monophasic isolate associated with broiler chickens but not considered pathogenic to humans (Huehn et al, 2009). It is of some interest that strain S04327-09 was the least invasive and poorest colonizer of the chicken.…”

“…In the UK, DT193 has emerged as a major phage type in human infection with some 48% of human isolates in 2010 of the phage type, and around one-half of these monophasic variants (Hopkins et al, 2012), and are also increasingly found in meat and poultry products in the USA (USDA, 2012). Monophasic Salmonella serotypes are considered an emerging problem in poultry that has also been implicated as a source of human infection (Huehn et al, 2009;DEFRA, 2012). The two major DT193 monophasic variants serotype 4,12:i:-and serotype 4,5,12:i:-have recently been isolated for the first time from UK poultry farms, with 12 incidents in 2010 and 2011 indicating their emerging threat to poultry production (DEFRA, 2012).…”

Genetic Types, Gene Repertoire, and Evolution of Isolates of the Salmonella enterica Serovar 4,5,12:i:− Spanish Clone Assigned to Different Phage Types

“…For these typing methods and the macrorestriction PFGE XbaI typing published by García et al DNA microarray analysis. DNA microarray analysis was performed as previously described (20). A total of 263 gene-specific 57-to 60-mer oligonucleotides, previously designed using the Array Designer 4.1 program (Premier Biosoft, Palo Alto, CA) according to Salmonella sequences from GenBank database (http://www.ncbi.nlm.nih.gov/), were included.…”

“…Signal values were normalized in order to present each data point as presence or absence. "Uncertain" hybridization probe signals (cutoff values between 0.25 and 0.4) were verified by PCR amplification as previously described (20), and individual decisions were made for the presence or absence of each target.…”

Prevalence of Salmonella enterica in Poultry and Eggs in Uruguay during an Epidemic Due to Salmonella enterica Serovar Enteritidis

“…Recently, it was reported that the monophasic serovar 4,12: d,Ϫ, which is highly adapted to poultry and is very rarely associated with human disease, lacks the galactonate and lpf operons (25). These genetic regions are present in S. Typhimurium and S. Enteritidis, which are serovars frequently asso-VOL.…”