• KSBB Journal
• /
• v.19 no.6 s.89
• /
• pp.446-450
• /
• 2004

We investigated the effective culture conditions of anaerobic bacteria, Enterobacter cloacae YJ-1 on hydrogen production. It was cultured with 60 mL of working volume at $35^{\circ}C$, 120 rpm for 40 h. With culture time, hydrogen production and cell growth increased, but residual glucose and pH decreased. When the $2\%$ of glucose was used as single carbon source, hydrogen production was 975.1 mL/L. To enhance hydrogen productivity, mixed carbon sources of glucose and sucrose were added. The maximum hydrogen production was earned at the mixing ratio of 25:75, and it was 1319.5 mL/L. When we added 50 mM of phosphate to protect the pH drop in culture broth, hydrogen production increased 1.3 times more than that of initial concentration. The organic nitrogen sources were more effective than inorganic nitrogen for hydrogen production. Among organic nitrogen, yeast extract was the most effective and its hydrogen production was 1691.3 mL/L. Among 9 of mineral sources, Ferric citrate and $NaMoO_4$ were especially effective, and their productions were 1782.3 mL/L and 1784.8 mL/L, respectively.

• Korean Journal of Veterinary Research
• /
• v.19 no.2
• /
• pp.131-134
• /
• 1979

In order to know the main causative agent and distribution of the agents in Gram-negative bacillus infections of bovine udders, one hundred and forty-eight cultures of Gram-negative bacilli isolated from clinical cases of mastitis during lactation over a period of 2 years in 6 herds of 180 Holstein cows were studied. Escherichia coli occupied 54.7% of the isolates was the most frequently isolated Gram-negative bacillus. 30 of the isolates (20.3%) were Enterobacter aerogenes, but Enterobacter cloacae was not isolated. Remaining isolates were Klebsiella pneumoniae, Proteus spp., Preudomonas aeruginosa and Alcaligenes faecalis. Most of the isolates (75.0%) were isolated from rear quarters.

• Food Science and Biotechnology
• /
• v.17 no.6
• /
• pp.1368-1371
• /
• 2008

In this study, 50 rump samples of raw beef obtained from local Korean supermarkets were analyzed to survey microbial distributions. As results, mesophilic microorganisms ranged from $(1.4{\pm}0.01){\times}10^2$ to $(1.6{\pm}0.05){\times}10^5\;CFU/g$, and total coliforms ranged from 0 to $(1.3{\pm}0.04){\times}10^4\;CFU/g$. Major foodborne pathogens, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp., were not found among the samples. However, Staphylococcus aureus was isolated with 4% frequency. Other isolated microorganisms included Enterobacter amnigenus (4%), Enterobacter cloacae (24%), E. coli (24%), Listeria innocua (8%), Staphylococcus saprophyticus (56%), Staphylococcus xylosus (10%), and Staphylococcus warneri (8%).

• Proceedings of the Zoological Society Korea Conference
• /
• 1996.10a
• /
• pp.201.1-201
• /
• 1996

No Abstract, See Full Text

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.8
• /
• pp.1144-1149
• /
• 2015

The aim of this study was to investigate the antioxidant and antimicrobial activities of various solvent (acetone, ethyl acetate, and ethanol) extracts from Lentinus edodes. The antioxidant activities were evaluated by measuring total polyphenol and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. Total polyphenol content and ABTS radical scavenging activity were highest in ethanol extract. ABTS radical scavenging activity of ethanol extract showed the highest value (98.5%), which was similar to that of ascorbic acid (95.7%). The ethyl acetate extract from Lentinus edodes showed relatively high total flavonoid content and DPPH radical scavenging activity. Negative correlations were found between total polyphenol contents and DPPH radical scavenging activities in Lentinus edodes extracts. Antimicrobial activities of the extracts were determined against Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter cloacae by the disc diffusion method. The acetone and ethanol extracts showed moderate antimicrobial activities against almost all tested microorganisms except E. coli and S. aureus, respectively. The ethyl acetate extract showed a significant growth inhibition effect against E. coli, Ent. cloacae, and B. subtilis.

• Korean Journal of Veterinary Service
• /
• v.43 no.2
• /
• pp.79-88
• /
• 2020

The aim of this study was to investigate the prevalence of CTX-M β-lactamase and plasmid-mediated quinolone resistance (PMQR) genes, and the pattern of antibiotic resistance in cefotaxime-resistant gramnegative bacteria. A total 126 gram-negative bacteria were isolated from hospitalized dogs and cats between 2018 and 2019. The most predominant isolates were E. coli (n=41), followed by Pseudomonas aeruginosa (n=25), Proteus mirabilis (n=14), Klebsiella pneumoniae (n=9), Sphingomonas paucimobilis (n=7), and Enterobacter cloacae and Serratia marcescens (respectively, n=5). Cefotaxime-resistant isolates were identified in 26.2% (33 isolates) of 126 gram-negative bacteria. CTX-M type β-lactamase were found in 15 isolates (10 E. coli, 1 Ent, cloacae and 4 K. pneumoniae, respectively). Among the CTX-M producing gram-negative bacteria, CTX-M-1 and CTX-M-9 were detected in 10 (66.7%) and 5 (33.3%) isolates, respectively. While, CTX-M-2 and CTX-M-8 were not found. PMQR genes were detected in 12 (36.4%) isolates (4 E. coli, 2 Ent, cloacae and 6 K. pneumoniae, respectively), and the predominant PMQR gene was aac(6')-lb-cr (n=9), followed by qnrB (n=8) and qnrS (n=1) alone or in combination. qnrA and qepA were not found. Additionally, 9 (60%) of 12 PMQR positive isolates were co-existence with CTX-M-1 or CTX-M-9. CTX-M or PMQR producing isolates showed highly resistance to penicillins (100%), cephalosporins (100~66.7%), monobactams (72.2%), and non-β-lactam antibiotics (94.4~61.1%) such as quinolones, trimethoprim/sulfamethoxazole, tetracycline and gentamicin. These findings showed CTX-M-1, CTX-M-9, aac(6')-lb-cr and qnrB were highly prevalent in cefotaxime-resistant Enterobacteriaceae isolates from companion animals in our region. Moreover, PMQR genes were closely associated with CTX-M type β-lactamase.

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.227-232
• /
• 1999

A total of 136 coliform bacteria isolated from spring water (112 strains) and ground water (24 strains), submitted to Seoul Health and Environmental Research Institute from June to July in 1997, were characterized biochemically and microbiologically. Colonical characteristics of each isolate were also noted, including color and texture on EMB agar. Among the 136 isolates, 50.7% were greenish metallic sheen color, 44.2% were pink and 5.1% were violet. The sixty four percent were smooth, 34.6% were mucoid and 0.7%. were rough. Twenty three bacterial species were identified by IMViC and API 20E test. Among the 136 coliform bacteria known to species, 39 isolates (28.6%) were Escherichia spp., 32 isolates (23.5%) were Klebsiella ssp., 30 isolates (22.1%) were Enterobacter spp., 19 isolates (14.0%) were Serratia spp., 6 isolates (4.4%) were Citrobacter spp., 4 isolates (3.0%) were Kluyvera spp. and 7 isolates (5.1%) were other bacterial species. Strains, which were gas-positive in lactose broth but gas-negative in Kligler Iron Agar were Ent. intermedium, Ser. liquefaciens, Ser. marcescenes and Salmonella arizoae. Strains, which were H2S production were also Kleb. pneumoniae, Kleb. oxytoca, Kleb. ornithinolytica, Ent. sahazahii, Ent. cloacae, Ser. liquefaciens, Ser. fica ria, Cit. freundii and Sal. arizoae. In the present study, most of coliform isolated from spring and ground water were E. coli, Klebsiella spp. and Enterobacter spp. Since coliform with pink colony in EMB agar was isolated as frequent as coliform with greenish metallic sheen colony, coliform with pink colony should be considered as important colony. Our results suggested that new coliform strains may be emerging on the basis of biochemical and microbiological testes.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.4
• /
• pp.428-435
• /
• 2019

The rapid increase and dissemination of carbapene mases, such as Klebsiella pneumoniae carbapenemase (KPC), has become a major problem within the field of healthcare-related infection. There are few antibiotics to treat carbapenem-resistant Enterobacteriaceae (CRE) infections, so the identification of resistant bacterial mechanisms is critical to initiate infection control and conduct epidemiological research. A rapid and effective method for detecting KPC-producing bacteria is needed to avoid therapeutic failures and introduce measures to prevent and control the dissemination of these multi-resistant bacteria. During the study period, 31 isolates (seven isolates of Acinetobacter spp., six isolates of Morganella morganii, five isolates of Pseudomonas aeruginosa, five isolates of Proteus mirabilis, one isolate of Proteus vulgaris, two isolates of Enterobacter cloacae, one isolate of Enterobacter aerogenes, one isolate of Klebsiella pneumoniae, one isolate of Klebsiella oxytoca, one isolate of Serratia marcescens and one isolate of Escherichia coli) were identified by the VITEK. Gram negative rod bacteria were the most frequently isolated from urine (35.5%), blood (19.4%), sputum (16.1%), pus (9.7%), ascitic fluid (9.7%), tracheal aspirates (6.5%) and bile juice (3.2%). Analysis using the PCR method identified the bla_KPC gene in the K. oxytoca1 strain, but the bla_IMP, bla_VIM and bla_OXA-48 genes are not amplified. In conclusion, diagnosis using the PCR method can accurately and quickly diagnose KPC, thus establishing quick preventive measures to prevent the spread of KPC in hospitals.

• Food Science of Animal Resources
• /
• v.29 no.4
• /
• pp.533-538
• /
• 2009

To suggest an improved diagnostic method for Salmonella spp., analyses were conducted with immunoliposomes and compared with the results from a commercial test kit. One sample out of 36 samples of eggshell was Salmonella-positive via immunoliposomes. In the case of the use of the commercial test kit, six samples out of 36 samples were Salmonellapositive. These Salmonella-positive samples were subjected to biochemical identification tests that confirmed that they were Salmonella-negative. As for the egg content samples, they were Salmonella-negative in both analyses with immunoliposomes and the commercial test kit. The Salmonella analysis with immunoliposomes reduced detection time, by 24 h compared to the commercial test kit. Bacteria, including Acinetobacter baumanni, Chryseomonas luteola, Enterobacter cloacae, Escherichia coli, Escherichia hermannii, Klebsiella pneumonia, Pantoea spp., and Pasteurella pneumotropica, were isolated from the eggshells. Other than Acinetobacter baumanni and Pasteurella pneumotropica most of the isolates were known to frequently appear during egg production processing.

• Childhood Kidney Diseases
• /
• v.10 no.2
• /
• pp.192-200
• /
• 2006

Purpose : This study was performed to identify longitudinal changes in the prevalence of organisms isolated from urinary tract infection(UTI) and in the pattern of Escherichia coli susceptibility to antibiotics during the past 10 years in children with UTI. Methods : We performed a retrospective study of a total of 192 urine cultures from children with UTI in the Department of Pediatrics, Seoul Adventist Hospital over two periods(1st: 1995-2000, 2nd:2001-2005). Antimicrobial susceptibility of the isolates was compared between the two groups. Results : The pathogens of UTI in the two groups were similar. In the first period, E. coli was the leading uropathogen(66.2%) followed by Klebsiella pneumoniae(7.8%), Enterobacter cloacae(6.5%), and others(19.5%). In the second period, E. coli was the leading uropathogen(67%) followed by K. pneumoniae(12.2%), E. cloacae(3.5%), Enterobacter aerogenes(3.5%), and others(13.8%). The susceptibility pattern of E. coli to amoxicillin/clavulanate(87.5%, 81.0%) did not present any statistically significant difference between the two periods(P>0.05). The susceptibility of E. coli to TMP/SMX(52.4%, 50.0%) was still low with no significant difference between the two periods(P>0.05). Conclusion : Our results suggest that the use of amoxicillin/clavulanate is still an excellent therapeutic option in children with UTI. The low rate of susceptibility to TMP/SMX against uropathogens suggest that TMP/SMX may be reevaluated as the first-line therapeutic drug for UTI.