High diversity of viable bacteria isolated from lymph nodes of slaughter pigs and its possible impacts for food safety

Abstract

This is the first study that broadly characterizes viable bacteria from ICLNs of pigs. The presence of bacteria in lymph nodes of farm animals has practical relevance for host colonization and possible chronic infection. It is also of great interest for basic research investigating translocation of bacteria from the gastrointestinal tract to ICLNs.

Interaction study of Pasteurella multocida with culturable aerobic bacteria isolated from porcine respiratory tracts using coculture in conditioned media

“…The isolation of Weeksella and Shewanella in the porcine lung agreed with the studies of Correa-Fiz et al [5], Siqueira et al [6], and Huang et al [8]. Our study identi ed Providencia in lung and Macrococcus in lymph node and lung consistent with Mann et al study [32]. Some discrepancies were also observed when compared the present results to other previous studies.…”

“…From 116 isolates, our study identi ed 14 bacterial genera, which included four aerobic (Acidovorax, Acinetobacter, Weeksella, and Wohlfahrtiimonas) and ten facultative anaerobic (Aeromonas, Escherichia, Enterobacter, Hafnia, Klebsiella, Macrococcus, Proteus, Providencia, Shewanella, and Shigella) bacterial genera belonging to seven families (Aeromonadaceae, Comamonadaceae, Enterobacteriaceae, Flavobacteriaceae, Moraxellaceae, Shewanellaceae, and Staphylococcaceae) under three phyla (Proteobacteria, Firmicutes, and Bacteroidetes) from the respiratory tracts of healthy pigs. The isolation of Proteobacteria, Firmicutes, and Bacteroidetes could be due to their abundance in the porcine respiratory tract as previously shown from the metagenomic studies of the nasal, oropharyngeal, and lung microbiota [6][7][8][31][32][33][34][35]. Some of these 14 bacterial genera were reported in similar locations of the porcine respiratory tract [5][6][7][8][31][32][33][34][35][36][37][38][39][40].…”

“…Some of these 14 bacterial genera were reported in similar locations of the porcine respiratory tract [5][6][7][8][31][32][33][34][35][36][37][38][39][40]. Acinetobacter, Aeromonas, Escherichia, Enterobacter, Klebsiella, Proteus, and Shigella were found in porcine nasal cavity, oropharynx, trachea, lymph node, and lung [5,6,8,[31][32][33][34][35][36][37]40]. However, only Acinetobacter, Klebsiella, and Proteus were isolated from the trachea, lymph node, and lung in the present study (Figure 1).…”

The Metabolically Active Bacterial Microbiome of Tonsils and Mandibular Lymph Nodes of Slaughter Pigs

“…Recently, three independent in-depth sequencing studies have provided evidence that the occurrence of high loads of microbial DNA in lymph nodes is not restricted to invasive pathogens and that a diverse microbiome exists in the lymph nodes of pigs, rats, and mule deer ( Wittekindt et al, 2010 ; Cuenca et al, 2014 ; Mann et al, 2014a ). Even if cultivation efforts have proven the existence of viable bacteria in lymph nodes; e.g., bacilli, Enterobacteriaceae, Clostridiaceae, Corynebacteriaceae , and Mycobacteriaceae ( Dahlinger et al, 1997 ; Pate et al, 2004 ; Mann et al, 2015 ), the diversity of the metabolically active part has not been investigated until now.…”

A Preliminary Study on the Presence of Salmonella in Lymph Nodes of Sows at Processing Plants in the United States

“…There has been limited research on prevalence of Salmonella in swine LN. Salmonella -positive LN represent a risk of contamination to pork products when incorporated into pork products, such as sausage, chorizo, and others [ 13 , 14 ]. The objective of this preliminary survey was to determine the presence of Salmonella in ventral superficial cervical LN and mandibular LN of sows at processing.…”