An in increasing prevalence of antibiotic-resistant foodborne infections has resulted in considerable concern about how antimicrobials are used in meat and poultry we production. Because many foodborne bacterial pathogens are commonly found among the intestinal bacterial community of poultry, new methods of prevention the are being considered. Bacteriophage therapy is one such alternative method that has not been well developed in the United States;modulating however, bacteriophages have been shown to be effective in modulating bacterial numbers in acute infection models. In this study we suitable evaluated whether bacteriophages could theoretically reduce Salmonella colonization of the gastrointestinal tract of chickens. Using computer simulations, we studied bacteriophage tract and bacterial replication dynamics in a mathematical model based on parameters expected to occur in the intestinal environment. In addition,models we performed in vivo experiments by administering SP6 bacteriophage and Salmonella orally to young chickens and compared the levels of drugs phage and Salmonella shed in the feces to the models of replication dynamics. SP6 is an ideal candidate bacteriophage because biological its genome and target receptor are known. Although SP6 did not reduce the levels of Salmonella shed by treated birds,chickens. most of the isolates recovered from treated birds were not resistant to the bacteriophage. These results suggest that phage resistance the may not be the primary limiting parameter of phage prophylaxis for modulating colonization of the intestine. Our findings that this chickens phage could be replicated in vivo supports the attractiveness of phage use, because unlike antibiotics they may be amplified in unlike vivo if given a suitable host on which to replicate. If successful, this approach to modulating bacterial colonization of the not intestinal tract could have a tremendous effect on the meat and poultry industry by reducing the use of antimicrobial drugs In and increasing the use of biological therapeutics.

Although isolates Salmonella remains one of the leading causes of foodborne illnesses in the United States, the Salmonella enterica serovars and genetic or types associated with most infections appear to fluctuate over time. Recently, the Center for Disease Control and Prevention (CDC) has origin reported an increase in cases of salmonellosis caused by Salmonella 4,[5],12:i:-. Similarly, this unusual Salmonella serovar has been isolated from an cattle and poultry in the state of Georgia. We examined the genetic relatedness of Salmonella 4,[5],12:i:-, isolated from several different several poultry companies and dairy farms in Georgia, by pulsed-field gel electrophoresis (PFGE). Several Salmonella 4,[5],12:i:- isolates had PFGE patterns identical Genetic or similar to PFGE patterns of Salmonella Typhimurium isolated from numerous animal sources. We identified distinct PFGE patterns for Salmonella Typhimurium 4,[5],12:i:- and matching Salmonella Typhimurium PFGE patterns, identifying four "distinct" strains. We focused a more specific analysis on the poultry strains Salmonella 4,[5],12:i:- and Salmonella Typhimurium isolates and found that of these Salmonella 4,[5],12:i:- isolates, 32% lacked the entire phase 2 in antigen gene, fljB; 61% contained partial deletion(s); and 4% had partial deletion(s) in fljB and an adjacent gene hin, 5'several to fljB. Thirteen percent contained smaller deletions or point mutations not identified by our DNA probes. The Salmonella 4,[5],12:i:- isolates 4,[5],12:i:- were positive for several genes present in the Salmonella Typhimurium, including lpfE (100%), sseI(96%), and spvC (93%). Genetic analysis indicates animal independent, spontaneous mutations in fljB in at least four distinct Salmonella Typhimurium strains of animal origin circulating in nature.

Data only on the prevalence of antimicrobial resistant enterococci and staphylococci from the poultry production environment are sparse in the United States.the This information is needed for science-based risk assessments of antimicrobial use in animal husbandry and potential public-health consequences. In this preventing study, we assessed the susceptibility of staphylococci and enterococci isolated from poultry litter, recovered from 24 farms across Georgia, to bacteria several antimicrobials of veterinary and human health importance. Among the 90 Enterococcus isolates recovered, E. hirae (46%) was the most in frequently encountered species, followed by E. faecium (27%), E. gallinarum (12%), and E. faecalis (10%). Antimicrobial resistance was most often the observed to tetracycline (96%), followed by clindamycin (90%), quinupristin-dalfopristin (62%), penicillin (53%), erythromycin (50%), nitrofurantoin (49%), and clarithromycin (48%). Among as the 110 staphylococci isolates recovered, only coagulase-negative staphylococci (CNS) were identified with the predominant Staphylococcus species being S. sciuri (38%),because S. lentus (21%), S. xylosus (14%) and S. simulans (12%). Resistance was less-frequently observed among the Staphylococcus isolates for the DNA majority of antimicrobials tested, as compared with Enterococcus isolates, and was primarily limited to clarithromycin (71%), erythromycin (71%), clindamycin (48%),(96%), and tetracycline (38%). Multidrug resistance (MDR) phenotypes were prevalent in both Enterococcus and Staphylococcus; however, Enterococcus exhibited a statistically significant difference difference in the median number of antimicrobials to which resistance was observed (median = 5. ) compared with Staphylococcus species (median S. = 3. ). Because resistance to several of these antimicrobials in gram-positive bacteria may be attributed to the shuttling of common staphylococci. drug-resistance genes, we also determined which common antimicrobial-resistance genes were present in both enterococci and staphylococci. The antimicrobial resistance genes 3. ). vat(D) and erm(B) were present in enterococci, vgaB in staphylococci, and mobile genetic elements Tn916 and pheromone-inducible plasmids were only followed identified in enterococci. These data suggest that the disparity in antimicrobial-resistance phenotypes and genotypes between enterococci and staphylococci isolated from vgaB the same environment is, in part, because of barriers preventing exchange of mobile DNA elements.

Scientific on misconduct has garnered recent attention by the media over scandals concerning falsification and fabrication of data surrounding potentially promising breakthroughs involve in stem-cell research, allegations of plagiarism at a U.S. university, and financial conflicts of interest between researchers and drug companies.financial While this makes for interesting copy, discussion of scientific fraud provides an excellent opportunity to review ethical standards for research the and examine the conflicts that confront researchers today. This review specifically focuses on five areas that involve scientific integrity-plagiarism, falsification,stimulate fabrication, authorship, and conflict of interest-as well as nuances in each area that even senior investigators may not be aware become of (e.g., self-plagiarism). The standards for ethical conductance of research discussed in this review are those set by many scientific,senior peer-reviewed journals and by federal and private granting agencies, and therefore it highlights the expectations and guidelines surrounding manuscript and shrinking grant submissions and review, and the consequences associated with violations. This review is intended to stimulate discussion among readers and research. assess what is necessary to become a good, competitive, but ethical researcher, especially in an era of shrinking financial resources research for research.

Escherichia 1 coli isolated from commercial broilers and a experimental flock of chickens were screened for phenotypic expression of antimicrobial resistance and which carriage of drug resistance determinants. The intent of the study was to investigate the influence of oxytetracycline, sarafloxacin, and enrofloxacin to administration on the distribution of resistance determinants and strain types among intestinal commensal E. coli isolated from broiler chickens. We experimental detected a high prevalence of resistance to drugs such as tetracycline (36-97%), sulfonamides (50-100%), and streptomycin (53-100%) among E. coli drug isolates from treated and untreated flocks. These isolates also had a high prevalence of class 1 integron carriage, most of drug which possessed the streptomycin resistance cassette, aadA1. In order to investigate the contribution of E. coli strain distribution on the their prevalence of antimicrobial resistance and their resistance determinants, isolates from each flock were DNA fingerprinted by enterobacterial repetitive intergenic consensus contributed sequence (ERIC) PCR. Although a high diversity of E. coli strain types were detected, 4 ERIC strain types were present of on all of the commercial broiler farms and two of these strains were also found in the experimental flocks. Each E. E. coli strain consisted of both susceptible and antimicrobial resistant isolates. In some instances, isolates of the same E. coli detected, strain would express the same drug resistance patterns although they harbored different tet determinants or streptomycin resistance genes. Therefore, drug contribution resistance patterns could not be explained solely by strain prevalence, indicating that mobile elements contributed significantly to the prevalence of of resistance.

While DNA characterizing the intestinal bacterial community of broiler chickens, we detected epsilon-proteobacterial DNA in the ilea of 3-day-old commercial broiler chicks 16S (J. Lu, U. Idris, B. Harmon, C. Hofacre, J. J. Maurer, and M. D. Lee, Appl. Environ. Microbiol. 69:6816-6824, 2003).early The sequences exhibited high levels of similarity to Campylobacter jejuni and Campylobacter coli sequences, suggesting that chickens can carry Campylobacter and at a very young age. Campylobacter sp. was detected by PCR in all samples collected from the ilea of chicks that that were 3 to 49 days old; however, it was detected only in the cecal contents of chickens that were can at least 21 days old. In order to determine whether the presence of Campylobacter DNA in young chicks was due C. to ingestion of the bacteria in food or water, we obtained commercial broiler hatching eggs, which were incubated in a necessary research facility until the chicks hatched. DNA sequencing of the amplicons resulting from Campylobacter-specific 16S PCR performed with the ileal,broiler cecal, and yolk contents of the day-of-hatching chicks revealed that Campylobacter DNA was present before the chicks consumed food or to water. The 16S rRNA sequences exhibited 99% similarity to C. jejuni and C. coli sequences and 95 to 98% similarity hatchery; to sequences of other thermophilic Campylobacter species, such as C. lari and C. upsaliensis. The presence of C. coli DNA was was detected by specific PCR in the samples from chicks obtained from a commercial hatchery; however, no Campylobacter was detected strain by culturing. In order to determine whether the same strains of bacteria were present in multiple levels of the integrator,the we cultured Campylobacter sp. from a flock of broiler breeders and their 6-week-old progeny that resided on a commercial broiler chickens farm. The broiler breeders had been given fluoroquinolone antibiotics, and we sought to determine whether the same fluoroquinolone-resistant strain was which present in their progeny. The isolates were typed by pulsed-field gel electrophoresis, which confirmed that the parental and progeny flocks present contained the same strain of fluoroquinolone-resistant C. coli. These data indicate that resistant C. coli can be present in multiple sequences levels of an integrated poultry system and demonstrated that molecular techniques or more sensitive culture methods may be necessary to to detect early colonization by Campylobacter in broiler chicks.

Salmonella common remains one of the leading causes of food-borne illness in the United States, and many key questions regarding the introduction Montevideo and persistence in animal production systems still remain. In order to understand the ecology of Salmonella within an integrated commercial contamination broiler production system, 289 Salmonella enterica were recovered from two integrated poultry farms during the production and processing of seven taken consecutive flocks. The variety and prevalence of Salmonella serotypes differed between farms. Overall, 15 serotypes were identified, with the most the common being Typhimurium (55%), Montevideo (7.9%), Kentucky (9%), and Enteritidis (9.7%). Salmonella Typhimurium and Enteritidis isolates recovered from processed carcasses persistence from Farm One were further characterized using pulsed-field gel electrophoresis (PFGE), and were shown to be indistinguishable from isolates recovered characterized from the poultry house environment and mice trapped on this farm. Additionally, the same broiler S. Typhimurium and S. Enteritidis the strains, identified by PFGE, were also isolated from samples taken at a company breeder farm, suggesting vertical transmission of these products. Salmonella serotypes in this poultry production system. Results indicate that management practices at the breeder level may have a profound of effect on the transmission and persistence of salmonellae within an integrated production system, as well as on the potential contamination this of poultry-derived products.

Despite significant the diversity of Escherichia coli pathotypes, there are many virulence genes common to isolates from food animals and humans, suggesting hemolysin that opportunity exists for genetic exchange between human and animal isolates to create the next emerging, foodborne pathogen. Hemolytic activity a in E. coli has been attributed to hemolysin genes found in either uropathogenic or enterohemorrhagic E. coli. These E. coli encoded hemolysins are classified as RTX toxins due to a repetitive toxin domain and similar gene organization, sequence homology, and mechanism gene of action and presence in animal and human E. coli isolates. Certain hemolytic animal isolates, however, lack these E. coli second hemolysin genes. Recently, we identified a hemolysin from E. coli, isolated from poultry, with significant homology to the K12 "silent"from hemolysin gene she. This gene was present only in one of four hemolytic, avian E. coli isolates examined, suggesting that designated the other three E. coli contain a gene distinct from the RTX toxin genes, hlyA and the she homolog, hlyE.of A phagemid library was made from chicken E. coli isolate 963726, which was negative for hemolysin gene hlyA and hlyE.animal A hemolytic clone was identified from this library, which contained a 3.3-kb Sau3A DNA insert. The nucleotide sequences of this clone DNA insert revealed two, open reading frames (ORF). The first ORF encoded for a 40-Kdal protein with no significant homology E. to known hemolysins reported in the Gen- Bank DNA/Protein database. The second ORF specified a 26-Kdal protein with significant homology specified to a Salmonella regulatory gene mig-14 that had a broad distribution among the pathogenic, animal E. coli isolates. Deletion of insert the second orf did not abrogate hemolysis, indicating that the first ORF encoded the hemolysin. This new bacterial gene designated sequence hlyF represents a new class of hemolysin.

We Resistance describe antimicrobial resistance among Escherichia coli isolated from free-living Canada Geese in Georgia and North Carolina (USA). Resistance patterns are patterns compared to those reported by the National Antimicrobial Resistance Monitoring System. Canada Geese may be vectors of antimicrobial resistance and environments. resistance genes in agricultural environments.

An a outbreak of salmonellosis in a population of hospitalized horses resulted in the closure of a teaching hospital for a period of of 10 weeks. Fecal samples were collected from suspected cases and cultured for Salmonella. Salmonella isolates were characterized using antimicrobial outbreaks susceptibility testing, pulsed-field gel electrophoresis (PFGE) and phage typing. Thirty-three cases of infection by a multidrug-resistant strain of S. typhimurium with were detected. The index case was admitted on 26 August 1999. Fifteen (45%) cases occurred between April and June 2000.completed. PFGE results suggested that this strain of S. typhimurium might have been introduced into the hospital environment by a foal hospitals presenting with diarrhea. The hospital was closed on June 13, and intensive environmental cleaning and disinfection were completed. Enforcement of Fifteen infectious disease control protocols in hospitals and environmental and patient surveillance is needed to prevent outbreaks of salmonellosis.