• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.11
• /
• pp.1715-1724
• /
• 2019

Objective: As laying hens become aged, laying performance and egg quality are generally impaired. One of the practical methods to rejuvenate production and egg quality of aged laying hens with decreasing productivity is a forced molting. However, the changes in intestinal microbiota after forced molting of aged hens are not clearly known. The aim of the present study was to analyze the changes in excreta bacterial communities after forced molting of aged laying hens. Methods: A total of one hundred 66-wk-old Hy-Line Brown laying hens were induced to molt by a 2-d water removal and an 11-d fasting until egg production completely ceased. The excreta samples of 16 hens with similar body weight were collected before and immediately after molting. Excreta bacterial communities were analyzed by high-throughput sequencing of bacterial 16S rRNA genes. Results: Bacteroidetes, Firmicutes, and Proteobacteria were the three major bacterial phyla in pre-molting and immediate post-molting hens, accounting for more than 98.0%. Lactobacillus genus had relatively high abundance in both group, but decreased by molting (62.3% in premolting and 24.9% in post-molting hens). Moreover, pathogenic bacteria such as Enterococcus cecorum and Escherichia coli were more abundant in immediate post-molting hens than in pre-molting hens. Forced molting influenced the alpha diversity, with higher Chao1 (p = 0.012), phylogenetic diversity whole tree (p = 0.014), observed operational taxonomic unit indices (p = 0.006), and Simpson indices (p<0.001), which indicated that forced molting increased excreta bacterial richness of aged laying hens. Conclusion: This study improves the current knowledge of bacterial community alterations in the excreta by forced molting in aged laying hens, which can provide increasing opportunity to develop novel dietary and management skills for improving the gastrointestinal health of aged laying hens after molting.

• Toxicological Research
• /
• v.35 no.3
• /
• pp.215-224
• /
• 2019

As various populations are rapidly becoming an aging society worldwide and interest in health issues has increased, demand for functional foods including herbal products has increased markedly to maintain a healthy state which has led to safety issues about their intake as an inevitable result. The objective of this study was to identify the safety profile of a Korean red ginseng and Salvia plebeia R. Br. extract mixture (KGC-03-PS) which is a valuable ingredient that can be used as a functional food. In the present study, the subacute oral toxicity and bacterial reverse mutagenicity of KGC-03-PS were evaluated. Sprague Dawley rats were administered KGC-03-PS orally for 28 days by gavage. Daily KGC-03-PS dose concentrations were 0, 500, 1,000, or 2,000 mg/kg body weight (bw) per day. Bacterial reverse mutation test with KGC-03-PS dose levels ranging from 312.5 to $5,000{\mu}g/plate$ was carried out by OECD test guideline No. 471. Five bacterial strains (Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2) were tested in the presence or absence of metabolic activation by plate incorporation method. There were no toxicological effects related with test substance in the clinical evaluation of subacute oral toxicity test including clinical signs, body weight, and food consumption. Moreover, no toxicological changes related to KGC-03-PS were observed in the hematological and serum biochemical characteristics as well as in the pathological examinations, which included organ weight measurements and in the gross- or histopathological findings. KGC-03-PS did not induce an increase in the number of revertant colonies in all bacterial strains of the bacterial reverse mutation test. The no-observed-adverse-effect level of KGC-03-PS is greater than 2,000 mg/kg bw/day, and KGC-03-PS did not induce genotoxicity related to bacterial reverse mutations under the conditions used in this study.

• Membrane and Water Treatment
• /
• v.10 no.1
• /
• pp.29-38
• /
• 2019

Microbial community and composition in stormwater runoff from mixed land use land cover (LULC) catchment with ongoing land development was diverse across the hydrological stage due different environmental parameters (hydrometeorological and physicochemical) and source of runoff. However, limited studies have been made for bacterial composition in this catchment. Therefore, this study aims to: (1) quantify the concentration of fecal indicator bacteria (FIB), stormwater quality and bacterial composition and structure according to hydrological stage; and (2) determine their correlation to environmental parameters. The 454 pyrosequencing was used to determine the bacterial community and composition; while Pearson's correlation was used to determine the correlation among parameters-FIB, stormwater quality, bacterial composition and structure-to environmental parameters. Results demonstrated that the initial and peak runoff has the highest concentration of FIB, stormwater quality and bacterial composition and structure. Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were dominant bacteria identified in this catchment. Furthermore, the 20 most abundant genera were correlated with runoff duration, average rainfall intensity, runoff volume, runoff flow, temperature, pH, organic matter, nutrients, TSS and turbidity. An increase of FIB and stormwater quality concentration, diversity and richness of bacterial composition and structure in this study was possibly due to leakage from septic tanks, cesspools and latrines; feces of domestic and wild animals; and runoff from forest, destroyed septic system in land development site and urban LULC. Overall, this study will provide an evidence of hydrological stage impacts on the runoff microbiome environment and public health perspective.

• Korean Journal of Veterinary Research
• /
• v.61 no.1
• /
• pp.4.1-4.6
• /
• 2021

Equine piroplasmosis (EP) is caused by Babesia caballi and Theileria equi infection. We investigated antigen and antibody of EP in horses in the Republic of Korea during 2016-2017. Antigen and antibody of T. equi was detected 0.06% (1/1,650). Phylogenetic analysis of 18S rRNA revealed that the T. equi was highly homologous with the strains from China, Mongolia, and Spain. Two Theileria spp. were also detected and highly homologous with T. buffeli, T. luwenshuni, and T. orientalis.

• Research in Plant Disease
• /
• v.29 no.4
• /
• pp.433-439
• /
• 2023

Bacterial leaf blight in carrot is one of the most important diseases in the worldwide. In the past decade, its introduction into Korea is causing great concern due to the potential damage to carrot crops domestically. This bacterial disease is caused by Xanthomonas hortorum pv. carotae (Xhc). This study aimed to isolate and identify bacterial strains from the soil of carrot farms in Jeju Island. The bacterial isolates showing characteristics similar with those of Xhc were selected when cultured on artificial media. Through DNA sequencing and analysis based on NCBI data, some of the selected bacterial strains were identified as Xhc. Furthermore, the bacterial strains caused the typical symptom of bacterial leaf blight after inoculation on carrot leaves. The results of this study showed the potential establishment of Xhc in the soil of Jeju Island and it may be valuable data for establish a strategy preventing the domestic spread of carrot bacterial leaf blight in the future.

• The Journal of the Korean Society for Microbiology
• /
• v.35 no.5_6
• /
• pp.371-371
• /
• 2000

• Proceedings of The Korean Society of Health Promotion Conference
• /
• 2005.11a
• /
• pp.199-233
• /
• 2005

• Pediatric Infection and Vaccine
• /
• v.4 no.1
• /
• pp.79-89
• /
• 1997

Purpose : Neonatal bacterial meningitis is the disease which clinical manifestations are nonspecific and several neurologic complications may occur. We studied neonatal bacterial meningitis, particularly in treatment and prognosis according to causative organisms -gram positive and gram negative bacteria- to assist in treatment of neonatal bacterial meningitis. Methods : We analysed twenty-four cases retrospectively who had been admitted in NICU or pediatric ward in Chung-ang Gil hospital from Jan. 1991 to Jun. 1996, and who had proven causative organisms in culture or latex agglutination[n test in CSF. Results : 1) The ratio of male to female was 2.4: 1. The mean birth weight and gestational age in cases with gram positive bacterial meningitis were $2.91{\pm}0.79kg$ and $38.4{\pm}2.74$ weeks and those in cases with yam negative bacterial meningitis were $3.30{\pm}0.90kg$ and $37.7{\pm}3.33$weeks respectively. There was no significant difference between the two groups. 2) The perinatal predisposing factors were pematurity, mecoinium staining amnionic fluid, matemal diabetes and pregnancy-induced hypertension, etc. The clinical manifestations Were fever, seizure, poor oral intake and fontanel bulging, etc. There were eleven cases with early onset bacterial meningitis(four cases by gram positive bacteria, seven cases by gram negative bacteria), and thirteen cases with late onset bacterial meningitis(seven cases by gram positive bacteria, six cases by gram negative bacteria). There was no significant difference between the two groups in terms of onset. 3) There were eleven cases with yam positive bacterial meningitis and they were coagulase-negative staphylococci(three cases), group B streptococci(three cases), Staphylococcus aureus(two cases), Streptococcus viridans(two cases), and enterococci(one case). And there were thirteen cases with gram negative bacterial menir gitis and they were Escherichia coli(seven cases), Klevsiella pneumoniae(three cases), Pseudomonas aeruginosa(one case), Acinetobactor(one case) and Enterobacter(one case). 4) The initial CSF WBC counts in cases with yam negative bacterial meningitis were significantly higher than those in cases with gram positive bacterial meningitis but the CSF protein and glucose levels were no significant difference in the two groups statistically. 5) The number of cases with abnormal findings in brain ultrasonography was seven in gram positive bacterial meningitis and ten in gram negative bacterial meningitis. 6) There were relatively high sensitivity to penicillin derivatives, the first generation cephalosporin and vancomycin in gram positive bacteria and to the third generation cephalosporin and amikacin in gram negative bacteria. 7) The mortality rate was 20.8%(5 cases were expired or discharged hopelessly). There was no significant difference between the two groups in prognosis. Conclusions : We recommend active treatment in noenatal bacterial meningitis to improve prognosis because the prognosis is poor.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.8 no.2
• /
• pp.83-88
• /
• 2003

A cellulose-producing strain isolated from rotten apples was identified as Gluconacetobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically named Gluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced by G. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producing G. hansenii PJK cells in the shear stress field from being converted into non-cellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss in the production yield.

• Korean Journal of Organic Agriculture
• /
• v.5 no.1
• /
• pp.87-99
• /
• 1996

Cultural conditions for mass production of the antagonistic bacteria, Bacillus subtills CAP134 against pathogens causing major airborne diseases to apple tree, effect of temperature, pH, carbon and nitrogen source in the culture broth were investigated. The bacterial growth was most vigorous when the temperature and pH of the culture broth was 30~$35^{\circ}$C, and 7, respectively. As for carbon source, dextrose was best followed in order by dextrose(monosaccharides)>sucrose(disaccharides)$\geq$saccharose(di-saccharides)>starch (polysaccharides). Among different sugars, bacterial growth was favored by in the order of brown, black and white sugars, indicating that the bacterial growth might be promoted by the minor elements presented as impurities in the less purified sugars. As for nitrogen source, organic forms were better to bacterial growth than inorganic forms, that is polypeptone was best followed in order by soy sauce, soybeen milk and inoganic nitrogens. Differences in bacterial growth among different forms of inorganic nitrogen were negligible.