Differential regulation of microRNA transcriptome in chicken lines resistant and susceptible to necrotic enteritis disease

Hong, Y.H.,Dinh, H.,Lillehoj, H.S.,Song, K.-D.,Oh, J.-D. POULTRY SCIENCE ASSOCIATION 2014 Poultry science Vol.93 No.6

Necrotic enteritis (NE) is a re-emerging disease as a result of increased restriction on the use of antibiotics in poultry. However, the molecular mechanisms underlying the pathogenesis of NE are unclear. Small RNA transcriptome analysis was performed using spleen and intestinal intraepithelial lymphocytes (IEL) from 2 inbred chicken lines selected for resistance or susceptibility to Marek's disease (MD) in an experimentally induced model of avian NE to investigate whether microRNA (miRNA) control the expression of genes associated with host response to pathogen challenge. Unique miRNA represented only 0.02 to 0.04% of the total number of sequences obtained, of which 544 were unambiguously identified. Hierarchical clustering revealed that most of miRNA in IEL were highly expressed in the MD-susceptible line 7.2 compared with MD-resistant line 6.3. Reduced CXCL14 gene expression was correlated with differential expression of several unique miRNA in MD-resistant chickens, whereas TGF beta R2 gene expression was correlated with altered gga-miR-216 miRNA levels in MD-susceptible animals. In conclusion, miRNA profiling and deep sequencing of small RNA in experimental models of infectious diseases may be useful for further understanding of host-pathogen interactions, and for providing insights into genetic markers of disease resistance.

Irradiation and additive combinations on the pathogen reduction and quality of poultry meat.

Ahn, Dong U,Kim, Il Suk,Lee, Eun Joo Poultry Science Association, etc 2013 Poultry science Vol.92 No.2

<P>Reduction of foodborne illnesses and deaths by improving the safety of poultry products is one of the priority areas in the United States, and developing and implementing effective food processing technologies can be very effective to accomplish that goal. Irradiation is an effective processing technology for eliminating pathogens in poultry meat. Addition of antimicrobial agents during processing can be another approach to control pathogens in poultry products. However, the adoption of irradiation technology by the meat industry is limited because of quality and health concerns about irradiated meat products. Irradiation produces a characteristic aroma as well as alters meat flavor and color that significantly affect consumer acceptance. The generation of a pink color in cooked poultry and off-odor in poultry by irradiation is a critical issue because consumers associate the presence of a pink color in cooked poultry breast meat as contaminated or undercooked, and off-odor in raw meat and off-flavor in cooked meat with undesirable chemical reactions. As a result, the meat industry has difficulties in using irradiation to achieve its food safety benefits. Antimicrobials such as sodium lactate, sodium diacetate, and potassium benzoate are extensively used to extend the shelf-life and ensure the safety of meat products. However, the use of these antimicrobial agents alone cannot guarantee the safety of poultry products. It is known that some of the herbs, spices, and antimicrobials commonly used in meat processing can have synergistic effects with irradiation in controlling pathogens in meat. Also, the addition of spices or herbs in irradiated meat improves the quality of irradiated poultry by reducing lipid oxidation and production of off-odor volatiles or masking off-flavor. Therefore, combinations of irradiation with these additives can accomplish better pathogen reduction in meat products than using them alone even at lower levels of antimicrobials/herbs and irradiation doses. Effects of irradiation and additive combinations on the pathogen reduction and quality of poultry meat will be discussed in detail.</P>

Prevalence and characterization of Salmonella species in entire steps of a single integrated broiler supply chain in Korea.

Choi, Soo-Won,Ha, Jong-Su,Kim, Byoung-Yoon,Lee, Dong-Hun,Park, Jae-Keun,Youn, Ha-Na,Hong, Young-Ho,Lee, Sang-Bae,Lee, Joong-Bok,Park, Seung-Yong,Choi, In-Soo,Song, Chang-Seon Poultry Science Association, etc 2014 Poultry science Vol.93 No.5

<P>The purpose of this study was to investigate the distribution of Salmonella species in an integrated broiler supply chain in Korea. A total of 1,214 samples from various steps of an integrated broiler production company including broiler breeder farms, broiler farms, broiler trucks, slaughterhouse, and retail chicken meats were collected and investigated. Salmonella was detected in 195 of the samples. The highest prevalence of Salmonella was observed in broiler transporting trucks (71.43%), followed by the slaughterhouse (63.89%) and broiler farms (16.05%). Salmonella Hadar was the most frequently isolated serotype (83.08%). All Salmonella Hadar isolates investigated in this study with pulsed-field gel electrophoresis showed the same XbaI pulsed-field gel electrophoresis pulsotype.</P>

Phylogenetic analysis and genetic characterization of chicken anemia virus isolates from Cambodia

Kye, Soo-Jeong,Kim, Ji-Ye,Seul, Hee-Jung,Kim, Seromi,Kim, Sang-Eun,Lee, Hee-Soo,Sorn, San,Choi, Kang-Seuk Poultry Science Association 2013 Poultry science Vol.92 No.10

<P>Three chicken anemia viruses (CAV) were detected by PCR during screening of field samples from village chickens collected in Cambodia in 2011/2012. Nearly full-length VP1 viral structural protein genes (nt 1–1,293) from the 3 CAV were sequenced and characterized. Phylogenetic analysis revealed that all 3 of the Cambodian CAV were clustered with CAV strains belonging to genotype II and were most closely related to CAV strains from Guangdong province, China. On the amino acid level, major substitutions were observed at 12 residues in the VP1 protein (positions 22, 75, 97, 125, 139, 144, 254, 287, 290, 370, 376, and 413) when compared with published reference CAV strains. In motifs associated with virulence, all Cambodian CAV had virulence-associated motifs composed of 75I, 89T, 125I, 139Q, 141Q, 144Q, and 394Q, which are commonly found in highly virulent genotype II viruses and some genotype III viruses. This is the first report of CAV isolated from village chickens in Southeast Asia as well as Cambodia.</P>

Geographical distribution of low pathogenic avian influenza viruses of domestic poultry in Vietnam and their genetic relevance with Asian isolates

Kim, Kwang-Il,Choi, Jun-Gu,Kang, Hyun-Mi,To, Thanh Long,Nguyen, Tho Dang,Song, Byung-Min,Hong, Mi-Seon,Choi, Kang-Seuk,Kye, Soo-Jeong,Kim, Ji-Ye,Lee, Hee-Soo,Lee, Youn-Jeong Poultry Science Association 2013 Poultry science Vol.92 No.8

<P>From the avian influenza virus (AIV) outbreaks and market surveillances in Vietnam during November 2011 and March 2012, a total of 196 AIV were isolated. Although H5N1 highly pathogenic avian influenza (HPAI) was the most prevalent subtype in Vietnam, 57 low pathogenic avian influenza (LPAI) viruses were identified from mainly domestic ducks and some chickens. Of note, various subtypes of LPAI viruses were isolated from domestic ducks in Vietnam: H3 (n = 16), H4 (n = 4), H6 (n = 24), H7 (n = 1), and H9 (n = 10). Geographically, the LPAI viruses were identified in different regions of Vietnam. Phylogenetic analysis of HA and NA genes in LPAIV in Vietnam showed that some H3 (group I) and H4 subtypes AIV clustered with the viruses of several Asian isolates from domestic poultry and wild birds. However, the H6, H9, and some H3 (group II and III) subtypes AIV were closely related to isolates from domestic poultry in Southern China. In addition, whereas the N2 and N6 subtypes AIV belonged to the Eurasian lineage, the N8 subtype AIV was classified to be both of Eurasian and American lineage. These findings revealed that the regional trade and wild birds play a key role transmission of LPAIV in domestic ducks in Vietnam. Further surveillance at the intercountry level is needed to understand the epidemiology of these viruses and to cope with emergence of novel AIV types.</P>

Prevalence and characteristics of intimin-producing Escherichia coli strains isolated from healthy chickens in Korea.

Oh, J-Y,Kang, M-S,An, B-K,Shin, E-G,Kim, M-J,Kim, Y-J,Kwon, Y-K Poultry Science Association, etc 2012 Poultry science Vol.91 No.10

<P>Virulent Escherichia coli strains have commonly been associated with diarrheal illness in humans and animals. Typical enteropathogenic Escherichia coli (EPEC) with intimin gene (eaeA) and E. coli adherence factor plasmid, or atypical EPEC with only eaeA have been implicated in human cases. In the present study, we investigated the prevalence of virulence-associated genes including eaeA in the E. coli strains isolated from cloacal specimens of 184 chicken flocks in 7 provinces in Korea between 2009 and 2010. When 7 virulence genes (VT1, VT2, LT, and ST for enterotoxigenic E. coli; eaeA and bfpA for enteropathogenic E. coli; and aggR for enteroaggregative E. coli) were screened by multiplex PCR, a total of 30 E. coli strains carrying only the eaeA gene were detected from 184 flocks that were identified as atypical enteropathogenic Escherichia coli (aEPEC). The aEPEC strains were analyzed by eae subtyping, phylogenetic grouping PCR, and serotyping. Twelve (40%) of 30 aEPEC strains possessed an eae-관 subtype, followed by 관 (30%), 관 (16.7%), and 관1 (13.3%). Eight (26.7%) of 30 aEPEC strains were designated into the phylogenetic group A. Two (6.7%) and 3 (10%) aEPEC strains were classified into the phylogenetic group B2 and D, respectively. A total of 15 (50%) aEPEC strains were serotyped to groups O24, O25, O26, O71, O80, O103, and O157, and the remaining strains were nontypeable. In analyzing the genetic diversity among the 30 aEPEC isolates by the pulsed-field gel electrophoresis method with XbaI-digestion, the pulsed-field gel electrophoresis profiling produced 20 different patterns, but isolates within the same group did not show clear geographic or breed relationships. Our data indicate that healthy chickens may constitute an important natural reservoir of aEPEC strains, and suggest that transmission to humans could not be excluded.</P>

Development and application of a multiplex PCR assay for rapid detection of 4 major bacterial pathogens in ducks

Wei, B.,Cha, S.-Y.,Kang, M.,Park, I.-J.,Moon, O.-K.,Park, C.-K.,Jang, H.-K. Poultry Science Association 2013 Poultry science Vol.92 No.5

<P>Infections with <I>Pasteurella multocida</I>, <I>Salmonella enterica</I>, <I>Riemerella anatipestifer</I>, and <I>Escherichia coli</I> result in high morbidity and mortality, which cause significant economic loss in the poultry industry. It can be difficult to distinguish these pathogens based on clinical signs because these pathogens can cause similar clinical signs and coinfections can occur. Thus, rapid and sensitive detection of these 4 major bacterial pathogens are important in ducks. The aim of this study was to develop a multiplex PCR (mPCR) assay for simultaneously detecting and identifying these 4 pathogenic bacteria in a single tube reaction. The target genes used were KMT1 of <I>P. multocida</I>, the invasion protein gene of <I>S. enterica</I>, 16S rDNA of <I>R</I>.<I> anatipestifer</I>, and the alkaline phosphatase gene of <I>E. coli</I>. The detection limit of the assay for all bacterial DNA was 10 pg. The mPCR did not produce any nonspecific amplification products when tested against other related pathogens, including <I>Staphylococcus aureus</I>, <I>Streptococcus pyogenes</I>, <I>Clostridium perfringens</I>, <I>Mycoplasma gallinarum</I>, <I>Mycoplasma synoviae</I>, and <I>Mycoplasma gallisepticum</I>, which can also infect ducks. We applied mPCR to field samples, and the results were the same as the single PCR results. These results suggest that mPCR for the 4 bacteria is a useful and rapid technique to apply to field samples.</P>

Genetic analyses of avian influenza viruses in Mongolia, 2007 to 2009, and their relationships with Korean isolates from domestic poultry and wild birds

Kang, H.-M.,Kim, M.-C.,Choi, J.-G.,Batchuluun, D.,Erdene-Ochir, T.-O.,Paek, M.-R.,Sodnomdarjaa, R.,Kwon, J.-H.,Lee, Y.-J. POULTRY SCIENCE ASSOCIATION 2011 Poultry science Vol.90 No.10

Live attenuated nephropathogenic infectious bronchitis virus vaccine provides broad cross protection against new variant strains.

Lim, T-H,Kim, M-S,Jang, J-H,Lee, D-H,Park, J-K,Youn, H-N,Lee, J-B,Park, S-Y,Choi, I-S,Song, C-S Poultry Science Association, etc 2012 Poultry science Vol.91 No.1

<P>Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide, and the emergence of new variant strains complicates disease control. The present study investigated the genetic and protectotypic features of newly emerged Korean IBV strains. A phylogenetic analysis showed that several recent isolates formed 2 different clusters (new cluster 1 and 2), which were distinct from other preexisting clusters. New cluster 1 IBV strains represented recombinants between Korean nephropathogenic strain KM91 and the QXIBV strain. New cluster 2 IBV strains showed low amino acid homology (<58.7%) compared with previous isolates. We evaluated the protective efficacy of commercial IBV vaccines (H120 and K2 strain) against these new isolates. In cross-protection studies, the H120 strain did not provide sufficient protection against these variants. However, highly attenuated nephropathogenic IBV vaccine, K2 strain, provided significantly higher levels of protection against variants compared with chickens vaccinated with H120 (P < 0.05 or better). These results indicate that the K2 vaccine could be helpful for the reduction of economic losses caused by newly evolving IBV recombinants (new cluster 1) and variants (new cluster 2).</P>

Epidemiology of egg drop syndrome virus in ducks from South Korea

Cha, S.-Y.,Kang, M.,Park, C.-K.,Choi, K.-S.,Jang, H.-K. Poultry Science Association 2013 Poultry science Vol.92 No.7

<P>Egg drop syndrome virus (EDSV) is an important pathogen of poultry that decreases egg production in chickens and causes respiratory disease in goslings. In 2011, we obtained serum samples from 139 domestic Pekin ducks, 416 one-day-old Pekin ducklings, and 75 wild ducks (67 mallards and 8 pintails) to survey their exposure to EDSV. A total of 123 of 139 sera (88.5%) from Pekin ducks, 396 of the ducklings (95.2%), and 16 of 67 mallards (23.9%) were positive. Field cases of EDSV in wild and domestic ducks were investigated. Six cases from domestic Pekin ducks were identified by PCR detection and were used for virus isolation and molecular analysis. Phylogenetic analyses of the partial hexon and full fiber genes showed that the D11-JW-012 and D11-JW-017 strains among 6 isolates belonged to different clusters compared with other known strains including the 127 strain. We assessed cell growth efficiency by hemagglutination (HA) titers and cytopathic effects in duck embryo liver cells and chicken embryo liver (CEL) cells to investigate host adaptation. The D11-JW-017 strain propagated more in chicken embryo liver than the D11-JW-012 strain and the field isolate from chickens. Our results demonstrate the high prevalence of EDSV in wild and domestic ducks in South Korea and provide information on EDSV from ducks that showed variable adaptability in chickens.</P>