Spatial distribution and risk factors associated withSalmonella entericain pigs

Abstract

The importance of pork in the transmission of Salmonella spp. to humans has led to the development of control programmes worldwide. For this, knowledge on the epidemiology of the infection in the production system is fundamental to the efficacy of the regulations. Our objective was to determine the prevalence and spatial distribution of Salmonella-infected farms in the central region of Argentina, and to identify the predominant serotypes and epidemiological factors associated with an increased risk of infection. Salmonella was isolated from 22 of 52 sampled farms, for a farm prevalence of 42·3% (95% confidence interval 28·4-56·1). The most frequent serotypes isolated were S. Typhimurium and S. Derby, which have often been considered of public health concern in the region. Limited evidences of global and local clustering in the region under study were found, and the type of feed and presence of diarrhoeic pigs were significantly associated with having Salmonella shedders in the farm. This highlights the need to evaluate microbiological controls at the farm level, and demonstrates the usefulness of the spatial tools to identify areas of greatest risk when processing pork at slaughterhouse, which could contribute to increasing the food safety of pork products.

Antibiotic resistance and associated resistance determinants in different Salmonella enterica serovars isolated from pigs in Argentina

“…We also included 35 strains from a previous study of 1518 fecal samples collected at 52 commercial farrow-to-finish pig farms in the region, where 22 farms tested positive for Salmonella spp. [ 4 ]. Isolates from clinical cases were recovered using conventional bacteriology with sheep blood agar and MacConkey agar, and mesenteric lymph nodes and fecal samples were analyzed according to ISO 6579:2002 standard.…”

“…The previous studies found that approximately 7-8% of the pork at retail markets in Argentina is contaminated with Salmonella spp. [ 2 , 3 ], but few studies have characterized this pathogen in local pig production farms [ 4 , 5 ]. Both pathogenic and non-pathogenic bacteria have become increasingly resistant to antibiotics in recent years because of increased administration of antibiotics, especially prophylactic in-feed antibiotics, in animal agriculture [ 6 ].…”

Infection, colonization and shedding of Campylobacter and Salmonella in animals and their contribution to human disease: A review

“…Salmonella are often isolated from healthy domestic pigs (Parada et al, ; Stevens & Gray, ). Occasionally, Salmonella ‐infected pigs may develop signs from transient fever to severe disease depending on strain virulence, immune resistance, route of infection and dose (Alsop, ; Schwartz, ).…”

Prevalence and associated risk factors of Salmonella spp. On the pork production chain in Córdoba, Argentina

“…The observed prevalence in Córdoba would be comparable to a similar study carried out in other provinces of Argentina (44.1%) in which 193 MLN samples were analyzed (Ibar et al, 2009). Furthermore, in another study, a Salmonella cluster was detected in pig farms located in the southern region of Córdoba (Parada et al, 2017). This epidemiological study shows that the prevalence of Salmonella is closely related to several factors, mainly associated with inadequate pre-slaughter practices at the slaughterhouse and with biosafety practices at the farms.…”