Heterogeneity of Persistence of Salmonella enterica Serotype Senftenberg Strains Could Explain the Emergence of this Serotype in Poultry Flocks

Abstract

Salmonella enterica serotype Senftenberg (S. Senftenberg) has recently become more frequent in poultry flocks. Moreover some strains have been implicated in severe clinical cases. To explain the causes of this emergence in farm animals, 134 S. Senftenberg isolates from hatcheries, poultry farms and human clinical cases were analyzed. Persistent and non-persistent strains were identified in chicks. The non-persistent strains disappeared from ceca a few weeks post inoculation. This lack of persistence could be related to the disappearance of this serotype from poultry farms in the past. In contrast, persistent S. Senftenberg strains induced an intestinal asymptomatic carrier state in chicks similar to S. Enteritidis, but a weaker systemic infection than S. Enteritidis in chicks and mice. An in vitro analysis showed that the low infectivity of S. Senftenberg is in part related to its low capacity to invade enterocytes and thus to translocate the intestinal barrier. The higher capacity of persistent than non-persistent strains to colonize and persist in the ceca of chickens could explain the increased persistence of S. Senftenberg in poultry flocks. This trait might thus present a human health risk as these bacteria could be present in animals before slaughter and during food processing.

Emergence and Prevalence of Non-H 2 S-Producing Salmonella enterica Serovar Senftenberg Isolates Belonging to Novel Sequence Type 1751 in China

“…Among the isolates, 153 (84%), 13 (7%), 6 (3%), 5 (3%), and 5 (3%) were isolated from humans, surface water, poultry, pork, and seafood, respectively. Previous studies have suggested that S. Senftenberg can contaminate food or water supplies (4,5). Molecular subtyping analysis showed that some isolates from food or water had a close relationship with the isolates from clinical patients.…”

“…In developed countries, NTS remains one of the leading causes of death among food-borne bacterial pathogen infections, and outbreaks are fairly common (2,3). Salmonella enterica serovar Senftenberg infections in humans have been associated with the consumption of poultry (4,5) and plant-derived food commodities (6). Although S. Senftenberg is an uncommon cause of human infections globally (7)(8)(9), including in China (10,11), increasing antimicrobial resistance supports the need for specific surveillance for this serotype (5,8).…”

Extremely Drug-Resistant Salmonella enterica Serovar Senftenberg Infections in Patients in Zambia

“…Senftenberg has also previously been reported as the cause of serious human infections (14)(15)(16). S. Senftenberg is well recognized as being common among poultry (17), but it has also been associated with infant formula (18), mussels (19), and vegetables (16,20,21). It is noteworthy that one of the patients claimed to have consumed vegetables prior to onset of symptoms.…”

Genomic and Phenotypic Analyses Reveal the Emergence of an Atypical Salmonella enterica Serovar Senftenberg Variant in China

“…Senftenberg isolates are often associated with colonization of hatcheries and are gradually eliminated during animal rearing. However, S. Senftenberg isolates that are able to persist throughout the rearing period into adulthood have recently emerged (15), with these same isolates displaying resistance to desiccation in soil (16). Clinically, infections caused by S. Senftenberg range from asymptomatic (17,18) to severe infections resulting in large out-breaks (19,20).…”