Substantial within-Animal Diversity of Salmonella Isolates from Lymph Nodes, Feces, and Hides of Cattle at Slaughter

Abstract

Lymph nodes (mandibular, mesenteric, mediastinal, and subiliac; n ‫؍‬ 68) and fecal (n ‫؍‬ 68) and hide (n ‫؍‬ 35) samples were collected from beef carcasses harvested in an abattoir in Mexico. Samples were analyzed for Salmonella, and presumptive colonies were subjected to latex agglutination. Of the isolates recovered, a subset of 91 was characterized by serotyping, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility phenotyping. Salmonella was isolated from 100% (hide), 94.1% (feces), 91.2% (mesenteric), 76.5% (subiliac), 55.9% (mandibular), and 7.4% (mediastinal) of samples. From the 87 typeable isolates, eight Salmonella enterica serotypes, including Kentucky (32.2%), Anatum (29.9%), Reading (17.2%), Meleagridis (12.6%), Cerro (4.6%), Muenster (1.1%), Give (1.1%), and Mbandaka (1.1%), were identified. S. Meleagridis was more likely (P ‫؍‬ 0.03) to be recovered from lymph nodes than from feces or hides, whereas S. Kentucky was more likely (P ‫؍‬ 0.02) to be recovered from feces and hides than from lymph nodes. The majority (59.3%) of the Salmonella isolates were pansusceptible; however, multidrug resistance was observed in 13.2% of isolates. Typing by PFGE revealed that Salmonella strains generally clustered by serotype, but some serotypes (Anatum, Kentucky, Meleagridis, and Reading) were comprised of multiple PFGE subtypes. Indistinguishable PFGE subtypes and, therefore, serotypes were isolated from multiple sample types, and multiple PFGE subtypes were commonly observed within an animal. Given the overrepresentation of some serotypes within lymph nodes, we hypothesize that certain Salmonella strains may be better at entering the bovine host than other Salmonella strains or that some may be better adapted for survival within lymph nodes. Our data provide insight into the ecology of Salmonella within cohorts of cattle and offer direction for intervention opportunities.

Serotypes of Salmonella isolated from feces of cattle, buffalo,and camel and sensitivities to antibiotics in Turkey

“…Salmonella isolates in calves were serotyped as S. Kentucky (8,20:i:z 6 ) (n = 19), S. Muenchen (6,8:d:1,2) (n = 5), S. Gaminare (16:d:1,7) (n = 4), S. Anatum (3,10, [15], [15,34]:e,h:1,6) (n = 3), S. Enteritidis (1, 9,12: g,m:-) (n = 1), and S. Muenster (3,10[15] [15,34]:e,h:1,5) (n = 1). Salmonella isolates in dairy cows were serotyped as S. Kentucky (8,20:i:z 6 ) (n = 3), S. Anatum (3,10, [15], [15,34]:e,h:1,6) (n = 1), and S. Typhimurium (1,4, [5],12:i:1,2) (n = 1).…”

“…Salmonella isolates in dairy cows were serotyped as S. Kentucky (8,20:i:z 6 ) (n = 3), S. Anatum (3,10, [15], [15,34]:e,h:1,6) (n = 1), and S. Typhimurium (1,4, [5],12:i:1,2) (n = 1). In addition, 1 isolate in buffalo was S. Kentucky (8,20:i:z 6 ) and the 1 isolate in camel was S. Abony (1,4, [5],12,27:b:e,n,x) ( Table 1). …”

“…Young calves and lambs frequently develop septicemia. Furthermore, marked depression, fever, symptoms of the central nervous system, pneumonia, and death within 2-3 days can also occur (7)(8)(9).…”

Perfil de resistencia a antibióticos de serotipos de Salmonella spp. aislados de carne de res molida en la Ciudad de México

“…22 En cualquier caso, la frecuencia relativa observada en este estudio dista mucho de ser baja, lo que indica que la carne bovina se mantiene como un vehículo potencial para la transmisión de Salmonella spp.…”

“…Además, la alta prevalencia del patógeno (55-91%) que suele observarse en los nódulos linfáticos, 22,24 los cuales son muy difíciles de eliminar por completo de la carne durante el faenado en los rastros, explica de manera plausible el hallazgo persistente de tasas de positividad a Salmonella spp., de moderadas a altas, en muestras de carne cruda en los puntos de venta a lo largo de décadas.…”