Investigation of Genetic Diversity of Pasteurella multocida Isolated from Diseased Poultry in Korea

ABSTRACT Pasteurella multocida causes fowl cholera which is an economically important disease in poultry industries around the world. In this study, we analyzed the capsular genotype, lipopolysaccharide (LPS) genotype, virulence-associated genes (VAGs) patterns, antimicrobial resistance and genetic diversity in a total of 9 P. multocida isolates from poultry with fowl cholera between 2014 and 2019 in Korea. When combining the capsular types with the LPS genotypes, two isolates of the 9 isolates were A:L3, and the others were non-typeable (NT): L3. Of the 23 VAGs, all the isolates harbored ptfA, fimA, hsf-1, hsf-2, pfhA, exbB, exbD, tonB, hgbA, hgbB, fur, sodA, sodC, pmHAS, ompA, ompH, oma87, plpB, psl, and nanH, whereas toxA gene was not detected in any of the 9 isolates. In addition, among the 11 antimicrobials, most of the isolates except for one isolate resistant to florfenicol, exhibited susceptibility to all the antimicrobials. Multi-locus sequence typing (MLST) analysis revealed 5 different sequence types (ST): ST8, ST351, ST352, ST353, and ST368. The ST351, ST352, ST353, and ST368 were identified for the first time in this study, and ST352 and ST353 isolates were largely prevalent nationwide. These STs isolates should be monitored continuously because in some cases, ST352 and ST353 isolates demonstrated high mortality rates. Although only limited numbers of isolates have been analyzed, our findings provide overall characteristics and epidemiological information of the P. multocida strains recently prevalent in Korea.

Standard body weight and serum estradiol and progesterone concentrations in response to total lysine content in female broiler breeders from 14 to 42 days after hatch

This study was conducted to determine the total lysine requirement for female broiler breeders from days 14 to 42. Two-hundred and ten female broiler breeders were used in a completely randomized design with 6 replicates per treatment and 5 chicks per pen under restricted feeding. The contents of total lysine used in this experiment were 0.68, 0.72, 0.76, 0.80, 0.84, 0.88 and 0.92% in the diet. A basal diet was formulated to meet or to exceed the Ross 308 female broiler breeders’ nutrient specifications except for the lysine. Body weight and feed intake were measured to calculate feed efficiency, and body weight uniformity was defined on a weekly basis. One chick per pen was randomly selected to collect blood samples, organ and an abundance of sexual maturity associated miRNAs (miR-21, mi-26a and mi-375) in the plasma was measured on day 42. Increasing total lysine contents in the diet improved body weight gain and feed conversion ratio from days 14 to 42. The combined values from the two models for BW, average daily gain and feed efficiency were estimated at 1.04, 1.00 and 1.21% total lysine, respectively. Total lysine contents did not affect the ovary weight, serum estradiol-17b, serum progesterone and plasma urea nitrogen or the expression levels of the three miRNAs on day 42. Therefore, the results from the current study indicated that female broiler breeders fed on 0.68% total lysine could achieve the recommended BW, suggested by field practice when data were fitted into the overlapped point of linear-, and quadratic-plateau models.

Standard body weight and serum estradiol and progesterone concentrations in response to total lysine content in female broiler breeders from 14 to 42 days after hatch

This study was conducted to determine the total lysine requirement for female broiler breeders from days 14 to 42. Two-hundred and ten female broiler breeders were used in a completely randomized design with 6 replicates per treatment and 5 chicks per pen under restricted feeding. The contents of total lysine used in this experiment were 0.68, 0.72, 0.76, 0.80, 0.84, 0.88 and 0.92% in the diet. A basal diet was formulated to meet or to exceed the Ross 308 female broiler breeders nutrient specifications except for the lysine. Body weight and feed intake were measured to calculate feed efficiency, and body weight uniformity was defined on a weekly basis. One chick per pen was randomly selected to collect blood samples, organ and an abundance of sexual maturity associated miRNAs (miR-21, mi-26a and mi-375) in the plasma was measured on day 42. Increasing total lysine contents in the diet improved body weight gain and feed conversion ratio from days 14 to 42. The combined values from the two models for BW, average daily gain and feed efficiency were estimated at 1.04, 1.00 and 1.21% total lysine, respectively. Total lysine contents did not affect the ovary weight, serum estradiol-17b, serum progesterone and plasma urea nitrogen or the expression levels of the three miRNAs on day 42. Therefore, the results from the current study indicated that female broiler breeders fed on 0.68% total lysine could achieve the recommended BW, suggested by field practice when data were fitted into the overlapped point of linear-, and quadratic-plateau models.(AU)

Population genetic characterization of the Japanese oak silkmoth, Antheraea yamamai (Lepidoptera: Saturniidae), using novel microsatellite markers and mitochondrial DNA gene sequences.

The Japanese oak silkmoth, Antheraea yamamai Guérin-Méneville, 1861 (Lepidoptera: Saturniidae), is an important natural resource of industrial value for silk fiber production. Owing to a lack of geographic and population genetic information, systematic domestication of An. yamamai has not been possible yet. In this study, 10 microsatellite markers developed using next-generation sequencing and two mitochondrial DNA (mtDNA) gene sequences (COI and ND4) were used to investigate the genetic variation and geographic structure of An. yamamai populations in South Korea. The two mtDNA gene sequences revealed very low total genetic variation and, consequently, low geographic variation, validating the use of more variable molecular markers. Genotyping of 76 An. yamamai individuals from nine localities in South Korea showed that the observed number of alleles at each locus ranged from 3 to 26, the polymorphism information content was 0.2990-0.9014, the observed and expected heterozygosities were 0.3252-0.9076 and 0.2500-0.9054, respectively, and FIS was -0.654-0.520. The population-based FIS, FST, RST, and global Mantel tests all suggested that the An. yamamai populations were overall well-interconnected, suggesting that any population can be used as a genetic source for domestication. Nevertheless, STRUCTURE analyses using microsatellite data and mtDNA sequences indicated the presence of two genetic pools in many populations, although a plausible explanation for this observation requires further studies.

Development of microsatellite markers for a hard-shelled mussel, Mytilus coruscus, and cross-species transfer.

The Korean mussel Mytilus coruscus, an endemic marine bivalve mollusk, is economically important. Its population is currently decreasing due to overexploitation and invasion of a more competitive species, Mytilus galloprovincialis. In this study, microsatellite markers for M. coruscus were developed using a cost-effective pyrosequencing technique. Among the 33,859 dinucleotide microsatellite sequences identified, 176 loci that contained more than 8 CA, CT, or AT repeats were selected for primer synthesis. Sixty-four (36.4%) primer sets were produced from the 100- to 200-bp polymerase chain reaction products obtained from 2 M. coruscus individuals. Twenty of these were chosen to amplify DNA from 82 M. coruscus individuals, and 18 polymorphic loci and 2 monomorphic loci were selected as microsatellite markers. The number of alleles and the allele richness of the polymorphic loci ranged from 2 to 22 and from 2.0 to 19.7 with means of 10.8 and 10.1, respectively. Null alleles were detected for all but three loci, which resulted in an observed heterozygosity lower than the expected heterozygosity and therefore an excess of homozygotes. In a cross-species transfer analysis of these markers using 7 Mytilidae species, the locus Mc65 was amplified from all species tested and was found to be polymorphic in all of them. Among the species, M. galloprovincialis, Lithophaga curta, and Hormomya mutabilis showed the same transferability of 25%, but the five amplified loci were polymorphic only in M. galloprovincialis and H. mutabilis. These microsatellite markers may be useful for future resource management and artificial production of juveniles for aquaculture.

Change of telomerase activity in peripheral whole blood of head and neck squamous cell carcinoma patients before and after surgery: a pilot study.

BACKGROUND The purpose of this study was to evaluate telomerase activity in peripheral whole blood from head and neck squamous cell carcinoma (HNSCC) patients as a biomarker for diagnosis of HNSCC or detection of recurrence during follow-up. MATERIALS AND METHODS Telomerase activity was measured from peripheral whole blood extracts by telomerase repeat amplification protocol (TRAP) in HNSCC patients before and after surgery and in a control group. Sixty-two HNSCC patients and 42 control subjects were included. RESULTS Telomerase activity was found in 41 out of 62 (66.1%) HNSCC patients before surgery and in 8 out of 42 (19.0%) controls (p<0.001). Among 41 HNSCC patients who showed positive telomerase activity before surgery, 32 (78.1%) showed a conversion of telomerase activity to negative after surgery. In follow-up, 6 out of 8 (75%) showed conversion of telomerase activity from negative to positive after recurrence. Telomerase activity was changed to negative in 4 out of 6 (66%) recurred patients with positive telomerase activity after second surgery. CONCLUSION The telomerase activity in peripheral whole blood extracts of HNSCC patients might be a useful biomarker for detecting recurrence after treatment. Further study with larger sample size using a more sensitive detection method of telomerase activity is necessary to verify these results.