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Faecal shedding and strain diversity of Listeria monocytogenes in healthy ruminants and swine in Northern Spain.

Esteban JI, Oporto B, Aduriz G, Juste RA, Hurtado A - BMC Vet. Res. (2009)

Bottom Line: Positive samples were subcultured onto the selective and differential agar ALOA and biochemically confirmed.Serotyping of 114 isolates identified complex 4b as the most prevalent (84.2%), followed by 1/2a (13.2%), and PFGE analysis of 68 isolates showed a highly diverse L. monocytogenes population in ruminant herds.These results suggested that cattle represent a potentially important reservoir for L. monocytogenes in the Basque Country, and highlighted the complexity of pathogen control at the farm level.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Health, NEIKER - Instituto Vasco de Investigación y Desarrollo Agrario, Berreaga 1, 48160 Derio, Bizkaia, Spain. jesteban@neiker.net

ABSTRACT

Background: Listeria monocytogenes is among the most important foodborne bacterial pathogens due to the high mortality rate and severity of the infection. L. monocytogenes is a ubiquitous organism occasionally present in the intestinal tract of various animal species and faecal shedding by asymptomatically infected livestock poses a risk for contamination of farm environments and raw food at the pre-harvest stages. The aim of this study was to determine the prevalence and strain diversity of L. monocytogenes in healthy ruminants and swine herds.

Results: Faecal samples from 30 animals per herd were collected from 343 herds (120 sheep, 124 beef cattle, 82 dairy cattle and 17 swine) in the Basque Country and screened in pools by an automated enzyme-linked fluorescent immunoassay (VIDAS) to estimate the prevalence of positive herds. Positive samples were subcultured onto the selective and differential agar ALOA and biochemically confirmed. L. monocytogenes was isolated from 46.3% of dairy cattle, 30.6% beef cattle and 14.2% sheep herds, but not from swine. Within-herd prevalence investigated by individually analysing 197 sheep and 221 cattle detected 1.5% of faecal shedders in sheep and 21.3% in cattle. Serotyping of 114 isolates identified complex 4b as the most prevalent (84.2%), followed by 1/2a (13.2%), and PFGE analysis of 68 isolates showed a highly diverse L. monocytogenes population in ruminant herds.

Conclusion: These results suggested that cattle represent a potentially important reservoir for L. monocytogenes in the Basque Country, and highlighted the complexity of pathogen control at the farm level.

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Related in: MedlinePlus

Map of the Basque Country. Counties are labelled with numbers (1–7 counties in Bizkaia; 8–13 in Araba; 14–20 in Gipuzkoa). Herd animal species sampled in each county are indicated (S, sheep; DC, dairy cattle; BC, beef cattle; Sw, swine), showing in brackets herd species that tested negative. Farms sampled for the Within-herd prevalence study are indicated in superscript.
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Figure 3: Map of the Basque Country. Counties are labelled with numbers (1–7 counties in Bizkaia; 8–13 in Araba; 14–20 in Gipuzkoa). Herd animal species sampled in each county are indicated (S, sheep; DC, dairy cattle; BC, beef cattle; Sw, swine), showing in brackets herd species that tested negative. Farms sampled for the Within-herd prevalence study are indicated in superscript.

Mentions: Healthy swine, cattle (beef and dairy) and dairy sheep herds were sampled to estimate L. monocytogenes prevalence in farms from the Basque Country, a 7,200-km2 region located in Atlantic northern Spain that is divided into three provinces, each of them formed by several counties: Bizkaia (counties 1–7 in Fig. 3), Araba (8–13) and Gipuzkoa (14–20). Swine production in the Basque Country is not very extensive (ca. 40,000 animals) and is based on indoor confinement systems mainly located in the southern counties. Approximately 40% of the population corresponds to suckling pigs that are fed elsewhere, whereas sows constitute 20% of the animals. The ovine population includes ca. 322,000 sheep of Latxa dairy breed that are commonly housed in winter and during milking (one lambing per year in November-March), but have access to summer communal mountain pastures. The cattle population includes c.a. 170,000 animals of which about 60% are beef cattle and the remaining 40% dairy cattle. Only occasionally do cattle and sheep herds share farm premises. In general, sheep and beef cattle spend most of the year pasture-grazing outdoors and during summer months they usually share mountain pastures, generally within the county but occasionally crossing county boundaries (see Fig. 3); conversely, dairy cattle are kept indoors throughout the year under a diet based on silage.


Faecal shedding and strain diversity of Listeria monocytogenes in healthy ruminants and swine in Northern Spain.

Esteban JI, Oporto B, Aduriz G, Juste RA, Hurtado A - BMC Vet. Res. (2009)

Map of the Basque Country. Counties are labelled with numbers (1–7 counties in Bizkaia; 8–13 in Araba; 14–20 in Gipuzkoa). Herd animal species sampled in each county are indicated (S, sheep; DC, dairy cattle; BC, beef cattle; Sw, swine), showing in brackets herd species that tested negative. Farms sampled for the Within-herd prevalence study are indicated in superscript.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2651128&req=5

Figure 3: Map of the Basque Country. Counties are labelled with numbers (1–7 counties in Bizkaia; 8–13 in Araba; 14–20 in Gipuzkoa). Herd animal species sampled in each county are indicated (S, sheep; DC, dairy cattle; BC, beef cattle; Sw, swine), showing in brackets herd species that tested negative. Farms sampled for the Within-herd prevalence study are indicated in superscript.
Mentions: Healthy swine, cattle (beef and dairy) and dairy sheep herds were sampled to estimate L. monocytogenes prevalence in farms from the Basque Country, a 7,200-km2 region located in Atlantic northern Spain that is divided into three provinces, each of them formed by several counties: Bizkaia (counties 1–7 in Fig. 3), Araba (8–13) and Gipuzkoa (14–20). Swine production in the Basque Country is not very extensive (ca. 40,000 animals) and is based on indoor confinement systems mainly located in the southern counties. Approximately 40% of the population corresponds to suckling pigs that are fed elsewhere, whereas sows constitute 20% of the animals. The ovine population includes ca. 322,000 sheep of Latxa dairy breed that are commonly housed in winter and during milking (one lambing per year in November-March), but have access to summer communal mountain pastures. The cattle population includes c.a. 170,000 animals of which about 60% are beef cattle and the remaining 40% dairy cattle. Only occasionally do cattle and sheep herds share farm premises. In general, sheep and beef cattle spend most of the year pasture-grazing outdoors and during summer months they usually share mountain pastures, generally within the county but occasionally crossing county boundaries (see Fig. 3); conversely, dairy cattle are kept indoors throughout the year under a diet based on silage.

Bottom Line: Positive samples were subcultured onto the selective and differential agar ALOA and biochemically confirmed.Serotyping of 114 isolates identified complex 4b as the most prevalent (84.2%), followed by 1/2a (13.2%), and PFGE analysis of 68 isolates showed a highly diverse L. monocytogenes population in ruminant herds.These results suggested that cattle represent a potentially important reservoir for L. monocytogenes in the Basque Country, and highlighted the complexity of pathogen control at the farm level.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Health, NEIKER - Instituto Vasco de Investigación y Desarrollo Agrario, Berreaga 1, 48160 Derio, Bizkaia, Spain. jesteban@neiker.net

ABSTRACT

Background: Listeria monocytogenes is among the most important foodborne bacterial pathogens due to the high mortality rate and severity of the infection. L. monocytogenes is a ubiquitous organism occasionally present in the intestinal tract of various animal species and faecal shedding by asymptomatically infected livestock poses a risk for contamination of farm environments and raw food at the pre-harvest stages. The aim of this study was to determine the prevalence and strain diversity of L. monocytogenes in healthy ruminants and swine herds.

Results: Faecal samples from 30 animals per herd were collected from 343 herds (120 sheep, 124 beef cattle, 82 dairy cattle and 17 swine) in the Basque Country and screened in pools by an automated enzyme-linked fluorescent immunoassay (VIDAS) to estimate the prevalence of positive herds. Positive samples were subcultured onto the selective and differential agar ALOA and biochemically confirmed. L. monocytogenes was isolated from 46.3% of dairy cattle, 30.6% beef cattle and 14.2% sheep herds, but not from swine. Within-herd prevalence investigated by individually analysing 197 sheep and 221 cattle detected 1.5% of faecal shedders in sheep and 21.3% in cattle. Serotyping of 114 isolates identified complex 4b as the most prevalent (84.2%), followed by 1/2a (13.2%), and PFGE analysis of 68 isolates showed a highly diverse L. monocytogenes population in ruminant herds.

Conclusion: These results suggested that cattle represent a potentially important reservoir for L. monocytogenes in the Basque Country, and highlighted the complexity of pathogen control at the farm level.

Show MeSH
Related in: MedlinePlus