scholarly journals Estimation of the Salmonella enterica prevalence in finishing swine

2004 ◽  
Vol 132 (1) ◽  
pp. 127-135 ◽  
Author(s):  
H. S. HURD ◽  
J. D. McKEAN ◽  
R. D. GRIFFITH ◽  
M. H. ROSTAGNO

The study objective was to evaluate three methods of Salmonella enterica prevalence estimation in swine herds (faecal culture, culture of abattoir-collected samples, and serum ELISA). From each of six swine herds, we necropsied approximately 100 finishing pigs (>70 kg); one-half on farm and the other half at the abattoir, after transport and approximately 2·5 h holding. We collected the same samples for S. enterica culture at both locations (1 g faecal, 10 g caecal contents, ileocaecal lymph nodes, superficial inguinal lymph nodes, 25 g of gluteal muscle for serum ELISA). On farm, the 1 g faecal sample only detected 13·3% (2/15) of all positive pigs necropsied on farm. However, with abattoir and on-farm results combined, the faecal sample detected 57·4% (74/129) of positive pigs. Abattoir-collected samples provided prevalence estimates much higher than on-farm collected samples (39·9 vs. 5·3%; P<0·001). This study shows that faecal samples have a low sensitivity for detecting infected pigs and that abattoir-collected samples overestimate the on-farm S. enterica prevalence. For most herds, serology overestimated the on-farm culture prevalence.

1997 ◽  
Vol 119 (2) ◽  
pp. 237-244 ◽  
Author(s):  
P. R. DAVIES ◽  
W. E. M. MORROW ◽  
F. T. JONES ◽  
J. DEEN ◽  
P. J. FEDORKA-CRAY ◽  
...  

We compared the prevalence of salmonella in faecal samples from finishing pigs and in feed samples from swine herds in North Carolina, USA. Farms were either finishing sites using all-in/all-out management of buildings in multiple-site systems (14 farms) or farrow-to-finish systems using continuous flow management of finishing barns (15 farms). The two groups of herds differed with respect to several management variables. Salmonella were isolated from 565 of 2288 (24·6%) faecal samples and from at least 1 faecal sample on 24 of 29 (83%) farms. Predominant serotypes were S. derby, S. typhimurium (including copenhagen), S. heidelberg, S. worthington and S. mbandaka. Fewer farrow-to-finish farms were detected as positive compared with all-in/all-out farms. Prevalence was lower for pigs raised on slotted floors compared with all other floor types, and was highest for pigs raised on dirt lots. Modern methods of raising pigs in multiple-site production systems, using all-in/all-out management of finishing pigs, appear to have no benefit in reducing the prevalence of salmonella compared with conventional farrow-to-finish systems.


2001 ◽  
Vol 64 (7) ◽  
pp. 939-944 ◽  
Author(s):  
H. SCOTT HURD ◽  
JAMES D. McKEAN ◽  
IRENE V. WESLEY ◽  
LOCKE A. KARRIKER

The objective of this paper was to evaluate the effect of lairage (holding &gt;12 h during transport to slaughter) in clean facilities on Salmonella isolation from market swine. We tested 30 market-bound pigs (about 240 lb [110 kg]) on each of 10 occasions from an Iowa farrow-to-finish operation with about 600 sows. All pigs were slaughtered, and samples were collected at a large Midwest abattoir. On the farm, fecal samples were collected for culture of Salmonella. Pigs were alternately assigned to a lairage treatment (holding in a clean, disinfected facility at the National Animal Disease Center) group or a control group (remaining on the farm). After about 18 h, both groups were transported (about 137 km) to a large Midwest abattoir, commingled, and slaughtered. After slaughter, samples were collected for culture of Salmonella (feces from the distal colon, ileocecal lymph nodes, cecal contents, ventral thoracic lymph nodes, subiliac lymph nodes, and carcass swabs). Diaphragm sections were collected for serum ELISA. Salmonella enterica Derby was the only serotype isolated from farm fecal samples (3.4%, 10 of 290). Multiple serotypes (n = 17) were isolated from 71.8% (196 of 273) of the pigs when abattoir-collected samples were cultured: cecal contents (21.2%, 58 of 273), distal colon contents (52%, 142 of 273), and ileocecal lymph nodes (43.6%, 119 of 273). There were lower Salmonella isolation rates from the lairaged pigs (P &lt; 0.05). The predominant serotype isolated at the abattoir varied by week of the study. This study suggests that pigs became internally contaminated with Salmonella after leaving the farm, possibly while in the abattoir holding pens, and that 18 h lairage, in clean facilities, does not increase shedding.


2002 ◽  
Vol 68 (5) ◽  
pp. 2376-2381 ◽  
Author(s):  
H. S. Hurd ◽  
J. D. McKean ◽  
R. W. Griffith ◽  
I. V. Wesley ◽  
M. H. Rostagno

ABSTRACT The objective of this study was to compare, by using identical sample types, the Salmonella enterica prevalences and serovar diversities between pigs necropsied on the farm and those necropsied at the abattoir after transport and holding. We necropsied 567 market weight pigs (>70 kg) from six herds. Pigs were alternately assigned to be necropsied on the farm or at the abattoir. One-half of the group was sent in clean, disinfected trailers to slaughter at a commercial abattoir. After transport (mean distance, 169 km) and 2 to 3 h of holding in antemortem pens, these pigs were necropsied. The 50 pigs remaining on the farm were necropsied the following day. The same sample types and amounts were collected for S. enterica culture at both locations. Results show a sevenfold-higher (P < 0.001) S. enterica isolation rate from pigs necropsied at the abattoir (39.9%; 114 of 286) than from those necropsied on the farm (5.3%; 15 of 281). This difference was also observed for each individual herd. All sample types showed a significantly higher prevalence when comparing abattoir to on-farm collection, respectively: lymph nodes, 9.15 versus 3.6%; cecal contents, 13.6 versus 1.8%; 1 g of fecal matter, 25.2 versus 0.7%. Recovery of additional serovars at the abattoir suggests the pigs are receiving S. enterica from extra-farm sources. This study demonstrates that rapid infection during transport, and particularly during holding, is a major reason for increased S. enterica prevalence in swine. This finding identifies the holding pen as an important S. enterica control point in the pork production chain.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 829
Author(s):  
Wim Gorssen ◽  
Dominiek Maes ◽  
Roel Meyermans ◽  
Jürgen Depuydt ◽  
Steven Janssens ◽  
...  

The use of antimicrobials in animal production is under public debate, mainly due to the risk of transfer of resistance to pathogenic bacteria in humans. Therefore, measures have been taken during the last few decades to reduce antibiotic usage in animals, for instance, by national monitoring programmes and by improving animal health management. Although some initiatives exist in molecular genetic selection, quantitative genetic selection of animals towards decreased antibiotic usage is an underexplored area to reduce antibiotic usage. However, this strategy could yield cumulative effects. In this study, we derived new phenotypes from on-farm parenteral antibiotic records from commercially grown crossbred finishing pigs used in the progeny test of Piétrain terminal sires to investigate the heritability of antibiotics usage. Parenteral antibiotic records, production parameters and pedigree records of 2238 full-sib pens from two experimental farms in Belgium between 2014 and 2020 were analysed. Heritability estimates were moderate (18–44%) for phenotypes derived from all antibiotic treatments, and low (1–15%) for phenotypes derived from treatments against respiratory diseases only. Moreover, genetic correlations between these new phenotypes and mortality were low to moderate (0.08–0.60) and no strong adverse genetic correlations with production traits were found. The high heritabilities and favourable genetic correlations suggest these new phenotypes, derived from on-farm antibiotics records, to be promising for inclusion in future pig breeding programs to breed for a decrease in antibiotics usage.


2006 ◽  
Vol 69 (4) ◽  
pp. 925-927 ◽  
Author(s):  
PETER B. BAHNSON ◽  
CLAUDIA SNYDER ◽  
LATIFA M. OMRAN

Because certain lymph nodes may be incorporated in food products, the presence of Salmonella enterica in these tissues could pose a food safety risk. We designed this two-part study to assess the prevalence of Salmonella in prescapular lymph nodes from normal slaughtered swine. Prescapular lymph nodes were collected from 300 systematically selected pigs in study 1 and, in study 2, from 75 pigs distributed among 10 herds. For study 2, pooled bacterial cultures were also completed on ileocecal lymph nodes, combining tissue from five pigs per pool (n = 60 pools). No Salmonella was detected in study 1 among prescapular lymph nodes (95% confidence interval, 0.0 to 1.16%). Salmonella was not detected in 75 prescapular lymph nodes from study 2, although Salmonella was detected in 5 of 10 herds in ileocecal lymph nodes. We conclude that prescapular lymph nodes posed a limited food safety risk in this population of pigs.


2019 ◽  
Vol 9 (3) ◽  
pp. 12-23
Author(s):  
G. F. Allakhverdieva ◽  
G. Т. Sinyukova ◽  
V. N. Sholokhov ◽  
Т. Yu. Danzanova ◽  
О. А. Saprina ◽  
...  

The study objective is to assess the capabilities of ultrasonography in the diagnosis of oropharyngeal squamous cell carcinomas and in the evaluation of treatment efficacy (changes in tumor volume).Materials and methods. This study included 98 patients (27 (27.5 %) females and 71 (72.5 %) males aged between 20 and 78 years with oropharyngeal tumors; of them, 12 (12.2 %) patients had recurrent tumors. Sixty-seven (68.4 %) participants had their tumors located in the tonsils; 31 (31.6 %) patients had tumors of the root of the tongue; 47 (48.0 %) patients presented with tumors invading adjacent tissues; 57 (58.2 %) patients had their lymph nodes involved. Thirty-two patients were operated at the first stage of treatment, whereas 66 (67.3 %) individuals received induction chemotherapy followed by sequential chemoradiotherapy. Treatment efficacy was evaluated 2 weeks following the completion of the second course of induction chemotherapy. We assessed tumor volume, its structure, type and intensity of vascularization, and the number and size of lymph nodes affected by metastasis. Ultrasonography findings were compared with the results of fibroscopy, X-ray computed tomography (CT) and magnetic resonance imaging (MRI) performed 2 weeks following the completion of the second course of induction chemotherapy (no later than 7–10 days).Results. The disagreement between histology and ultrasonography findings reflecting tumor volume (of either newly diagnosed or recurrent tumor) was statistically insignificant. The results of X-ray CT were more likely to be in agreement with histology than the ultrasonography results (85.0 % vs 70.0 %); however, this difference was not statistically significant. Data of X-ray CT and ultrasonography on the tumor volume demonstrated no significant difference between them. MRI and ultrasonography findings on the tumor volume were consistent in 50 % of cases. We identified the most common changes in the structure of the oropharyngeal tumors typical of positive and negative dynamics after 2 courses of induction chemotherapy. Patients with positive dynamics demonstrated a significant decrease in tumor volume detected by all diagnostic methods used (ultrasonography, X-ray CT, and MRI). There was a significant negative correlation between the efficacy of treatment assessed by ultrasonography and the grade of therapeutic pathomorphosis assessed by histology (r = –0.69; р = 0.0014).Conclusion. The accuracy of ultrasonography for the estimation of oropharyngeal tumor volume and its spread is comparable with that of X-ray CT and MRI. The disagreement between these methods was statistically insignificant. Ultrasonography is a more sensitive method for the evaluation of patient response to treatment than clinical data.


2021 ◽  
Author(s):  
Wim Gorssen ◽  
Dominiek Maes ◽  
Roel Meyermans ◽  
Jurgen Depuydt ◽  
Steven Janssens ◽  
...  

The use of antimicrobials in animal production is under public debate, mainly due to the risk of transfer of resistance to pathogenic bacteria in humans. Therefore, measures have been taken during the last decades to reduce antibiotic usage in animals, for instance by national monitoring programmes and by improving animal health management. Although some initiatives exist in molecular genetic selection, quantitative genetic selection of animals towards decreased antibiotic usage is an underexplored area to reduce antibiotic usage. However, this strategy could yield cumulative effects. In this study we derived new phenotypes from on-farm parenteral antibiotic records from commercially grown crossbred finishing pigs used in the progeny test of Pietrain terminal sires to investigate the heritability of antibiotics usage. Parenteral antibiotic records, production parameters and pedigree records of 2238 full-sib pens from two experimental farms in Belgium between 2014 and 2020 were analysed. Heritability estimates were moderate (18-44%) for phenotypes derived from all antibiotic treatments, and low (1-15%) for phenotypes derived from treatments against respiratory diseases only. Moreover, genetic correlations between these new phenotypes and mortality were low to moderate (0.08-0.60) and no strong adverse genetic correlations with production traits were found. The high heritabilities and favourable genetic correlations suggest these new phenotypes derived from on-farm antibiotics records to be promising for inclusion in future pig breeding programs to breed for a decrease in antibiotics usage.


2012 ◽  
Vol 49 (No. 10) ◽  
pp. 379-388 ◽  
Author(s):  
L. Matlova ◽  
L. Dvorska ◽  
M. Bartos ◽  
J. Docekal ◽  
M. Trckova ◽  
...  

An increased incidence of tuberculous lesions in head and mesenteric lymph nodes from slaughtered pigs weighing about 115 kg was recorded in a herd of pigs kept in two farms A and B in the CzechRepublic. Tuberculous lesions were more frequently (P &lt; 0.01) diagnosed in pigs from Farm A (10.4%) than from Farm B (1.1%). The follow-up investigation of potential sources of infection on Farm A revealed that the piglets were fed kaolin from a nearby mine as a supplement. Among 20 samples from the pigs&rsquo; environment, atypical conditionally pathogenic mycobacteria (ACPM) were detected in four samples as follows: dust (n = 2), pig faeces (n = 1) and kaolin fed as a supplement (n = 1). Mycobacterium avium subsp. hominissuis of genotype IS901&ndash; and IS1245+ and serotype 8 was isolated from kaolin and pig lymph nodes, M. fortuitum from stable dust and pig faeces and other ACPM from stable dust. When kaolin feeding to piglets ceased, the incidence of tuberculous lesions in these pigs at slaughter 5&ndash;6 months later decreased from 16.1% to 3.4%. No ACPM was detected on Farm B in 27 samples from the environment. An investigation of surface kaolin mines did not detect mycobacteria in non-extracted kaolin. However, surface water (three isolates among 13 samples) from the pond used for kaolin levigation and 23 batches of the final product of kaolin (10 samples from each batch, i.e. a total of 230 samples were examined) were contaminated with ACPM. Among the latter, ACPM were isolated from three samples originating from three different batches. ACPM were likely to survive during transport of the kaolin, as a suspension through the pipeline, and during its further processing to the final product (sedimentation, addition of colloid substances, drying and other procedures).


2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Prerna Vohra ◽  
Christina Vrettou ◽  
Jayne C. Hope ◽  
John Hopkins ◽  
Mark P. Stevens

AbstractSalmonella enterica is a veterinary and zoonotic pathogen of global importance. While murine and cell-based models of infection have provided considerable knowledge about the molecular basis of virulence of Salmonella, relatively little is known about salmonellosis in naturally-affected large animal hosts such as cattle, which are a reservoir of human salmonellosis. As in humans, Salmonella causes bovine disease ranging from self-limiting enteritis to systemic typhoid-like disease and exerts significant economic and welfare costs. Understanding the nature and consequences of Salmonella interactions with bovine cells will inform the design of effective vaccines and interventions to control animal and zoonotic infections. In calves challenged orally with S. Dublin expressing green fluorescent protein (GFP) we observed that the bacteria were predominantly extracellular in the distal ileal mucosa and within gut-associated lymph nodes 48 h post-infection. Intracellular bacteria, identified by flow cytometry using the GFP signal, were predominantly within MHCII+ macrophage-like cells. In contrast to observations from murine models, these S. Dublin-infected cells had elevated levels of MHCII and CD40 compared to both uninfected cells from the same tissue and cells from the cognate tissue of uninfected animals. Moreover, no gross changes of the architecture of infected lymph nodes were observed as was described previously in a mouse model. In order to further investigate Salmonella-macrophage interactions, net replication of S. enterica serovars that differ in virulence in cattle was measured in bovine blood-derived macrophages by enumeration of gentamicin-protected bacteria and fluorescence dilution, but did not correlate with host-specificity.


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