Isolation and identification of a genus, Chromobacterium, not previously found on processed poultry.
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An organism identified as Chromobacterium lividum was isolated from processed poultry in Georgia. (+info)
Characterization of H5N1 influenza viruses that continue to circulate in geese in southeastern China.
(58/1054)
The H5N1 influenza virus, which killed humans and poultry in 1997, was a reassortant that possibly arose in one type of domestic poultry present in the live-poultry markets of Hong Kong. Given that all the precursors of H5N1/97 are still circulating in poultry in southern China, the reassortment event that generated H5N1 could be repeated. Because A/goose/Guangdong/1/96-like (H5N1; Go/Gd) viruses are the proposed donors of the hemagglutinin gene of the H5N1 virus, we investigated the continued circulation, host range, and transmissibility of Go/Gd-like viruses in poultry. The Go/Gd-like viruses caused weight loss and death in some mice inoculated with high virus doses. Transmission of Go/Gd-like H5N1 viruses to geese by contact with infected geese resulted in infection of all birds but limited signs of overt disease. In contrast, oral inoculation with high doses of Go/Gd-like viruses resulted in the deaths of up to 50% of infected geese. Transmission from infected geese to chickens occurred only by fecal contact, whereas transmission to quail occurred by either aerosol or fecal spread. This difference is probably explained by the higher susceptibility of quail to Go/Gd-like virus. The high degree of susceptibility of quail to Go/Gd (H5N1)-like viruses and the continued circulation of H6N1 and H9N2 viruses in quail support the hypothesis that quail were the host of origin of the H5N1/97 virus. The ease of transmission of Go/Gd (H5N1)-like viruses to land-based birds, especially quail, supports the wisdom of separating aquatic and land-based poultry in the markets in Hong Kong and the need for continued surveillance in the field and live-bird markets in which different types of poultry are in contact with one another. (+info)
Molecular evolution of H6 influenza viruses from poultry in Southeastern China: prevalence of H6N1 influenza viruses possessing seven A/Hong Kong/156/97 (H5N1)-like genes in poultry.
(59/1054)
The A/teal/Hong Kong/W312/97 (H6N1) influenza virus and the human H5N1 and H9N2 influenza viruses possess similar genes encoding internal proteins, suggesting that H6N1 viruses could become novel human pathogens. The molecular epidemiology and evolution of H6 influenza viruses were characterized by antigenic and genetic analyses of 29 H6 influenza viruses isolated from 1975 to 1981 and 1997 to 2000. Two distinct groups were identified on the basis of their antigenic characteristics. Phylogenetic analysis revealed that all H6N1 viruses isolated from terrestrial poultry in 1999 and 2000 are closely related to A/teal/Hong Kong/W312/97 (H6N1), and the nucleotide sequences of these viruses and of A/Hong Kong/156/97 (H5N1) were more than 96% homologous. The hemagglutinin (HA) of the 1999 and 2000 terrestrial viruses does not have multiple basic amino acids at the site of cleavage of HA1 to HA2; however, a unique insertion of aspartic acid in HA1 between positions 144 and 145 (H3 numbering) was found. The neuraminidase of these terrestrial H6N1 viruses has a deletion of 19 amino acids characteristic of A/Hong Kong/156/97 (H5N1). Evolutionary analysis suggested that these H6N1 viruses coevolved with A/quail/Hong Kong/G1/97-like H9N2 viruses and became more adapted to terrestrial poultry. These terrestrial 1999 and 2000 A/teal/Hong Kong/W312/97 (H6N1)-like viruses, along with the H9N2 viruses, could have been involved in the genesis of the pathogenic H5N1 influenza viruses of 1997. The presence of H6N1 viruses in poultry markets in Hong Kong that possess seven of the eight genes of the A/Hong Kong/156/97 (H5N1) virus raises the following fundamental questions relevant to influenza pandemic preparedness: could the pathogenic H5N1 virus reemerge and could the H6N1 viruses directly cross the species barrier to mammals? (+info)
Cooperation between the hemagglutinin of avian viruses and the matrix protein of human influenza A viruses.
(60/1054)
To analyze the compatibility of avian influenza A virus hemagglutinins (HAs) and human influenza A virus matrix (M) proteins M1 and M2, we doubly infected Madin-Darby canine kidney cells with amantadine (1-aminoadamantane hydrochloride)-resistant human viruses and amantadine-sensitive avian strains. By using antisera against the human virus HAs and amantadine, we selected reassortants containing the human virus M gene and the avian virus HA gene. In our system, high virus yields and large, well-defined plaques indicated that the avian HAs and the human M gene products could cooperate effectively; low virus yields and small, turbid plaques indicated that cooperation was poor. The M gene products are among the primary components that determine the species specificities of influenza A viruses. Therefore, our system also indicated whether the avian HA genes effectively reassorted into the genome and replaced the HA gene of the prevailing human influenza A viruses. Most of the avian HAs that we tested efficiently cooperated with the M gene products of the early human A/PR/8/34 (H1N1) virus; however, the avian HAs did not effectively cooperate with the most recently isolated human virus that we tested, A/Nanchang/933/95 (H3N2). Cooperation between the avian HAs and the M proteins of the human A/Singapore/57 (H2N2) virus was moderate. These results suggest that the currently prevailing human influenza A viruses might have lost their ability to undergo antigenic shift and therefore are unable to form new pandemic viruses that contain an avian HA, a finding that is of great interest for pandemic planning. (+info)
Antibiotic resistance of faecal enterococci in poultry, poultry farmers and poultry slaughterers.
(61/1054)
The prevalence of resistance in enterococci to antibiotics, commonly used for therapy in poultry or as antimicrobial growth promoters (AMGPs), was determined in faecal samples of two chicken populations: broilers in which antibiotic and AMGP use is common and laying-hens with a low antibiotic usage. In addition faecal samples were examined from three human populations: broiler farmers, laying-hen farmers and poultry slaughterers. MICs of an extended panel of antibiotics for a randomly chosen gentamicin- or vancomycin-resistant enterococcal isolate from each faecal specimen were also determined. The prevalence of resistance for all antibiotics tested was higher in broilers than in laying-hens. Resistance in faecal enterococci of broiler farmers was for nearly all antibiotics higher than those observed in laying-hen farmers and poultry slaughterers. The overall resistance in broilers was correlated with the resistance in broiler farmers and in poultry slaughterers. No correlation between the results obtained in the laying-hens with any of the other populations was found. The 27 gentamicin-resistant isolates all showed high-level resistance to gentamicin and two of these isolates, both Enterococcus faecium, were resistant to all antibiotics tested, except vancomycin. The 73 vancomycin-resistant enterococci (VRE) isolated from the five populations belonged to four different species and in all isolates the vanA gene cluster was detected by blot hybridization. The pulsed-field gel electrophoresis (PFGE) patterns of these vancomycin-resistant enterococci were quite heterogeneous, but Enterococcus hirae isolates with the same or a closely related PFGE pattern were isolated at two farms from the broiler farmer and from broilers. Molecular characterization of vanA-containing transposons of these isolates showed that similar transposon types, predominantly found in poultry, were present. Moreover, similar vanA elements were not only found in isolates with the same PFGE pattern but also in other VRE isolated from both humans and chickens. The results of this study suggest transmission of resistance in enterococci from animals to man. For VRE this might be clonal transmission of animal strains, but transposon transfer seems to occur more commonly. (+info)
Dried poultry waste for cows grazing low-quality winter forage.
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Two trials conducted in 1996-97 measured BW and body condition score changes of cows fed different sources of degradable intake protein, including dried poultry waste and soybean meal, while grazing low-quality winter forages. In Trial 1, 60 spring-calving cows (5 yr; 555 kg) were used in an individual supplementation trial. Cows were gathered three times a week, sorted into individual pens, and fed their respective supplement. Cows grazed dormant native Sandhills winter range (common pasture) and were assigned to one of six supplemental treatments: 1) no supplement, 2) urea, 3) 22% dried poultry waste + urea, 4) soybean meal, 5) 22% dried poultry waste + soybean meal, or 6) 44% dried poultry waste. All supplements were based on wheat middlings and soybean hulls and were formulated to contain 44% CP. Thirty-six cows were selected randomly (six per treatment) for a 5-d measurement of forage intake from December 16 through December 20, 1996. Cows receiving supplements gained more weight (P < 0.001) and maintained greater body condition (P < 0.001) than unsupplemented cows. Cows receiving urea gained less (P < 0.10) than cows receiving a source of natural protein, but body condition remained similar. No differences were found in daily forage or total organic matter intake (P > 0.10). In Trial 2, cows grazed corn residues. Forty-eight spring-calving cows were group-fed supplements in one of six 4-ha paddocks. Cows received supplements containing either soybean meal or dried poultry waste that were the same as the soybean meal and 44% dried poultry waste supplements fed in Trial 1; gains were not different (P > 0.10). Under the economic conditions that existed at the time of these experiments, the supplement containing dried poultry waste resulted in a savings of $.04 per cow per day and a total savings of $3.20 per cow over an 80-d period. Feeding a supplement containing dried poultry waste resulted in performance similar to that when feeding a more conventional supplement containing soybean meal. (+info)
Risk of influenza A (H5N1) infection among poultry workers, Hong Kong, 1997-1998.
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In 1997, outbreaks of highly pathogenic influenza A (H5N1) among poultry coincided with 18 documented human cases of H5N1 illness. Although exposure to live poultry was associated with human illness, no cases were documented among poultry workers (PWs). To evaluate the potential for avian-to-human transmission of H5N1, a cohort study was conducted among 293 Hong Kong government workers (GWs) who participated in a poultry culling operation and among 1525 PWs. Paired serum samples collected from GWs and single serum samples collected from PWs were considered to be anti-H5 antibody positive if they were positive by both microneutralization and Western blot testing. Among GWs, 3% were seropositive, and 1 seroconversion was documented. Among PWs, approximately 10% had anti-H5 antibody. More-intensive poultry exposure, such as butchering and exposure to ill poultry, was associated with having anti-H5 antibody. These findings suggest an increased risk for avian influenza infection from occupational exposure. (+info)
Identification of genetic differences between two Campylobacter jejuni strains with different colonization potentials.
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The consumption of poultry meat contaminated with Campylobacter jejuni is considered to be a risk factor for human campylobacteriosis. The development of targeted strategies to control campylobacters in broilers would benefit from knowledge of those bacterial factors important in colonization of the avian gut. During preliminary studies it was noted that C. jejuni NCTC 11168 was a poorer colonizer of chickens than strain 81116. This poor colonization could not be fully restored by in vivo passage, suggesting that it was a genetically endowed property of strain 11168. As the genome sequence is available for this strain, the technique of subtractive hybridization was used to identify gene fragments of strain 81116 not present in strain 11168. After two screening cycles, 24 out of 42 clones were identified as having DNA inserts specific for strain 81116. Six of these 24 clones contained gene fragment inserts with similarities to restriction-modification enzymes found in other bacteria. Two inserts had similarity to arsenic-resistance genes, whereas four others had similarities to cytochrome c oxidase III, dTDP-glucose 4,6-dehydratase, gamma-glutamyl transpeptidase and an abortive phage-resistance protein. At least some of these genes may be involved with colonization. A further six inserts had weak similarities to hypothetical proteins or to proteins with assigned functions from strain 11168. The remaining six clones had gene-fragment inserts with no database matches. Southern-blot analysis confirmed that strain-dependent variation existed for each of these DNA inserts. These results indicate that subtractive hybridization can successfully identify genes that are absent from the only C. jejuni strain for which the genome sequence is currently available. (+info)