Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by L.R. Bielke
Total Records ( 4 ) for L.R. Bielke
  S.E. Higgins , J.P. s Higgin , L.R. Bielke and B.M. Hargis
  The objective of this study was to select appropriate bacteriophages that survive in the gastrointestinal tract of neonatal poultry and utilize those bacteriophages to reduce intestinal colonization of Salmonella enteritidis phage type 13A (SE) in challenged birds. Broiler chicks served as an in vivo biological filter to preferentially select bacteriophages from our bacteriophage library capable of surviving the gastrointestinal environment. A mixture of bacteriophage isolates designated PHL 1-71 was administered orally to three SE challenged chicks on three consecutive days. Each day, bacteriophages were recovered from the ileum, ileocecal junction and ceca for sequential administration the following day. The recovered bacteriophages were then administered to SE-infected turkey poults. In the first experiment, two-day old poults were challenged with 104cfu SE and treated 48 h later with 5mM Mg (OH)2 followed by 2.5×109 plaque forming units (pfu) of bacteriophages in 1mM Mg (OH)2 solution. This treatment numerically reduced SE recovered from cecal contents at 12 and 24 h after treatment as compared to untreated controls. In a second experiment, two-day old poults were challenged with 1.6×104 cfu SE and treated with 5mM Mg (OH)2 followed by 7.5×109 pfu phage in 1mM Mg (OH)2 solution 48 h post-challenge. We recovered 79,728 cfu of SE per g of cecal contents in the control group and 11,224 cfu/g in the phage treated group 24 h post treatment. These data were not significantly different, but they suggest that bacteriophages can be preferentially selected in vivo to increase survival in the avian gastrointestinal tract. However, improved efficacy is required prior to useful application of the approach for reducing Salmonella infection.
  A.D. Wolfenden , J.L. Vicente , L.R. Bielke , C.M. Pixley , S.E. Higgins , D.J. Donoghue , A.M. Donoghue , B.M. Hargis and G. Tellez
  Effective Competitive Exclusion (CE) cultures have been shown to accelerate development of normal microflora in chicks and poults, providing increased resistance to infection by some enteric bacterial pathogens. Our objective was to develop a CE culture for prophylaxis and reduced horizontal transmission of Salmonella enteritidis (SE) in broiler chickens. In the present study, seven members of the family Enterobacteriaceae and 2 lactic acid bacteria isolates, each capable of in vitro and in vivo inhibition of SE, were selected and combined to form the putative CE culture. In the first experiment, day-of-hatch chicks were randomly divided into four pens. All treated chicks were orally gavaged with the CE culture and 3 pens were treated with the CE culture in the drinking water for four consecutive days. Treated and control-non treated chicks were challenged with SE on day 4. All 3 groups of birds that were treated with the CE culture had a significant decrease (p<0.05) in cecal colonization compared with non-CE-treated SE-challenged chicks. Two additional experiments were designed to measure the efficacy of the CE culture in reducing SE horizontal transmission from infected to uninfected chicks when commingled. SE was recovered in the cecal tonsils with a significantly lower incidence at days 7 and 14 in Experiment 2 and day 7 in Experiment 3 from the groups that received the CE in the drinking water as compared to controls respectively. These results suggest that a relatively simple and defined CE culture can reduce SE colonization in neonatal chicks.
  A. M. Donoghue , L.R. Bielke , S. E. Higgins , D. J. Donoghue , B. M. Hargis and G. Tellez
  Bacteriophages used to treat infections are typically amplified in a pathogenic host. However, this practice introduces the risk of administering any remaining bacteriophage-resistant pathogen during bacteriophage application if separation techniques are less than perfect. In this study, bacteriophage isolates capable of replicating in both Salmonella and Klebsiella oxytoca were identified and applied to poultry carcasses. These Wide-Host-Range bacteriophages (WHR) were amplified using the non-pathogenic bacteria, Klebsiella oxytoca in tryptic soy broth until a titer of ~109 PFU/mL was obtained. WHR and Klebsiella oxytoca were not separated prior to treatment of carcasses. Fresh processed chicken carcasses were inoculated with either Salmonella enteritidis (SE) or S. typhimurium (ST), sprayed with 5 mL of WHR and rinsed with sterile water. Samples were enriched, plated on XLD agar and evaluated for Salmonella-typical colonies. In four separate trials, WHR significantly reduced the recovery of SE. No SE was detected in two trials and a greater than 70% reduction was seen in the other two trials. ST was also significantly reduced in the two trials in which it was included (p<0.05). These experiments suggest that WHR could be an inexpensive and safe method for the reduction of Salmonella on broiler carcasses.
  H.P. Bhaskaran , A.M. Donoghue , K. Arsi , A. Wooming , I. Reyes-Herrera , L.R. Bielke , G. Tellez , J.A. Byrd , P.J. Blore , B.M. Hargis and D.J. Donoghue
  The administration of nonpathogenic microflora in neonatal poultry has been employed to reduce or eliminate the colonization of enteric pathogens. This concept, also called Competitive Exclusion (CE), although effective against Salmonella, has not consistently worked against Campylobacter. Most CE cultures are developed by randomly collecting enteric bacteria without any preselection criteria for bacteria. It may be possible to enhance the efficacy of a CE against Campylobacter by preselecting enteric microflora with the ability to inhibit Campylobacter, in vitro. With this goal, an assay was developed to test individual isolates with the ability to reduce or eliminate Campylobacter growth, in vitro. Individual isolates (n = 137) were collected from ceca of both juvenile and adult poultry and tested for efficacy against Campylobacter. Isolates were serially diluted (104 or 105 CFU/well) and added to 96 well polystyrene plates containing 1 x 104 CFU C. jejuni or C. coli/well. Plates were incubated at 42°C in a microaerophilic environment for 24-48 h. Following incubation, a 1 μl loop from each well was streaked onto Campy-Cefex agar plate and incubated at 42°C in a microaerophilic environment for 24-48 h. Twenty-three isolates were identified with the ability to inhibit C. jejuni or C. coli growth in vitro. This research demonstrates that it is possible to pre-screen enteric isolates for Campylobacter inhibition for use as competitive exclusion cultures.
 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility