Use of heavy metals in swine feed and its association with the co-selection of metal tolerant and multi-drug resistant Salmonella

This study was conducted to characterize the role of chemical interventions, biocides and heavy metal micronutrients, in particular, in swine production systems on the emergence of heavy metal and biocide tolerant Salmonella and its association with antimicrobial resistance. A total of 353 Salmonella isolates with different antimicrobial resistance profiles identified from 36 barns exposed to three different classes of biocides were analyzed. The sources of isolates included feed (n=30), fecal (n=226), and environment (n=97) samples that were systematically selected

Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA

Detection and distribution of a Rocky Mountain spotted fever group Rickettsia sp. and Babesia microti from Ixodes scapularis in Indiana counties

In Indiana, Ixodes scapularis is an important tick in public health because it feeds on a variety of hosts including humans, and transmits Borrelia burgdorferi (Lyme disease), Anaplasma phagocytophilum (human granulocytic ehrlichiosis), and Babesia microti (babesiosis). Symbiotic, non-pathogenic Rickettsia found in Ixodes scapularis may play a role in excluding pathogenic species of Rickettsia from being transovarially transmitted. In order to investigate this idea further in Indiana, a total of 378 adult I. scapularis from 4 different counties (Jasper, Pulaski, Newton and Starke) were tested by polymerase chain reaction analysis (PCR) for the presence of Rickettsia sp. Four positive samples from the PCR (using Rocky Mountain spotted fever group specific primers to target the rOmpA gene; Rr190.70p and RH 90.602n) reactions were sequenced to verify identity. These four samples matched closest to the reference number AB002268 from GenBank which describes, I. scapularis endosymbiont DNA for rOmpA. A total of 62 engorged females were tested; 53 (85.5%) harbored the rickettsial symbiont. A total of 41 questing females were tested; 33 (80.5%) were positive. Of the 249 males tested, 14 (5.6%) were positive. A restriction digestion on some of the positive samples revealed that the 1 scapularis symbiont was different from R. montana and R. rickettsii. The second goal of this study was to identify the presence of B. microti. In I. scapularis ticks, this would be the first time this pathogen was identified in Indiana. To accomplish this goal 106, ticks were tested using the primers Babl and Bab4, which target the 18S rRNA gene specific for B. microti. Three tick samples were found to harbor B. microti as determined by sequencing. However, sequencing of amplification band in the negative control also yielded B. microti. Thus, the presence of B. microti in Indiana ticks could not be confirmed. A negative control was also sequenced and was identified as Babesia microti indicating that there was a contamination so it is not possible to conclude that B. microti was found in Indiana ticks.Thesis (M.S.)Department of Physiology and Health Scienc

Use of heavy metals in swine feed and its association with the co-selection of metal tolerant and multi-drug resistant Salmonella

This study was conducted to characterize the role of chemical interventions, biocides and heavy metal micronutrients, in particular, in swine production systems on the emergence of heavy metal and biocide tolerant Salmonella and its association with antimicrobial resistance. A total of 353 Salmonella isolates with different antimicrobial resistance profiles identified from 36 barns exposed to three different classes of biocides were analyzed. The sources of isolates included feed (n=30), fecal (n=226), and environment (n=97) samples that were systematically selected.</p

Activity of Sangrovit® against Lawsonia intracellularis in grower pigs and its impact on gut physiology and host immunity

Sanguinarine, a quaternary benzophenanthridine alkaloid plant extract of Macleya cordata, has demonstrated to have anti-inflammatory, antimicrobial and immunomodulatory effect. It increases the availability of aromatic amino acids and decreases the levels of toxic biogenic amines. This study was aimed to evaluate the effect of Sangrovit® supplementation as compared to tylosin on growth performance, feed efficiency and Lawsonia intracellularis shedding in pigs, and to determine the effect of Sangrovit® on the immune system. A total of 24 pigs, four weeks-old challenged with Lawsonia intracellularis were randomly allocated to a treatment group (control non-supplemented, 40 g Sangrovit®/mton, 75 g Sangrovit®/mton, and 22g /kg tylosin). Pigs were weighed weekly and average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were calculated.</p

Activity of Sangrovit® against Lawsonia intracellularis in grower pigs and its impact on gut physiology and host immunity

Sanguinarine, a quaternary benzophenanthridine alkaloid plant extract of Macleya cordata, has demonstrated to have anti-inflammatory, antimicrobial and immunomodulatory effect. It increases the availability of aromatic amino acids and decreases the levels of toxic biogenic amines. This study was aimed to evaluate the effect of Sangrovit® supplementation as compared to tylosin on growth performance, feed efficiency and Lawsonia intracellularis shedding in pigs, and to determine the effect of Sangrovit® on the immune system. A total of 24 pigs, four weeks-old challenged with Lawsonia intracellularis were randomly allocated to a treatment group (control non-supplemented, 40 g Sangrovit®/mton, 75 g Sangrovit®/mton, and 22g /kg tylosin). Pigs were weighed weekly and average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were calculated

Genotypic and phenotypic properties of cattle-associated Campylobacter and their implications to public health in the USA.

Since cattle are a major source of food and the cattle industry engages people from farms to processing plants and meat markets, it is conceivable that beef-products contaminated with Campylobacter spp. would pose a significant public health concern. To better understand the epidemiology of cattle-associated Campylobacter spp. in the USA, we characterized the prevalence, genotypic and phenotypic properties of these pathogens. Campylobacter were detected in 181 (19.2%) out of 944 fecal samples. Specifically, 71 C. jejuni, 132 C. coli, and 10 other Campylobacter spp. were identified. The prevalence of Campylobacter varied regionally and was significantly (P<0.05) higher in fecal samples collected from the South (32.8%) as compared to those from the North (14.8%), Midwest (15.83%), and East (12%). Pulsed Field Gel Electrophoresis (PFGE) analysis showed that C. jejuni and C. coli isolates were genotypically diverse and certain genotypes were shared across two or more of the geographic locations. In addition, 13 new C. jejuni and two C. coli sequence types (STs) were detected by Multi Locus Sequence Typing (MLST). C. jejuni associated with clinically human health important sequence type, ST-61 which was not previously reported in the USA, was identified in the present study. Most frequently observed clonal complexes (CC) were CC ST-21, CC ST-42, and CC ST-61, which are also common in humans. Further, the cattle associated C. jejuni strains showed varying invasion and intracellular survival capacity; however, C. coli strains showed a lower invasion and intracellular survival potential compared to C. jejuni strains. Furthermore, many cattle associated Campylobacter isolates showed resistance to several antimicrobials including ciprofloxacin, erythromycin, and gentamicin. Taken together, our results highlight the importance of cattle as a potential reservoir for clinically important Campylobacter

Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA.</p