• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.413-418
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• 2014

Hydatid cyst caused by Echinococcus granulosus is one of the most important parasitic diseases around the world and many countries in Asia, including Iran, are involved with this infection. This disease can cause high mortality in humans as well as economic losses in livestock. To date, several molecular methods have been used to determine the genetic diversity of E. granulosus. So far, identification of E. granulosus using real-time PCR fluorescence-based quantitative assays has not been studied worldwide, also in Iran. Therefore, the aim of this study was to investigate the genetic diversity of E. granulosus from center of Iran using real-time PCR method. A total of 71 hydatid cysts were collected from infected sheep, goat, and cattle slaughtered in Isfahan, Iran during 2013. DNA was extracted from protoscolices and/or germinal layers from each individual cyst and used as template to amplify the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) (420 bp). Five cattle isolates out of 71 isolates were sterile and excluded from further investigation. Overall, of 66 isolates, partial sequences of the cox1 gene of E. granulosus indicated the presence of genotypes G1 in 49 isolates (74.2%), G3 in 15 isolates (22.7%), and G6 in 2 isolates (3.0%) in infected intermediate hosts. Sixteen sequences of G1 genotype had microgenetic variants, and they were compared to the original sequence of cox1. However, isolates identified as G3 and G6 genotypes were completely consistent with original sequences. G1 genotype in livestock was the dominant genotype in Isfahan region, Iran.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.2
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• pp.105-114
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• 2016

The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and baseline viability prior to cryopreservation and were assessed again at three time points; one week (T1), 18 months (T2), and 36 months (T3). DPSC can be grouped based on their observed doubling times; slow (sDT), intermediate (iDT), and rapid (rDT). Viability results demonstrated all three types of DPSC isolates (sDT, iDT and rDT) exhibit time-dependent reductions in viability following cryopreservation, with the greatest reduction observed among sDT-DPSCs and the smallest observed among the rDT-DPSC isolates. Cryopreserved DPSCs demonstrate time-dependent reductions in cellular viability. Although reductions in viability were smallest at the initial time point (T1) and greatest at the final time point (T3), these changes were markedly different among DPSC isolates with similar doubling times (DTs). Furthermore, the analysis of various DPSC biomarkers - including both intracellular and cell surface markers, revealed differential mRNA expression. More specifically, the relative high expression of Sox-2 was only found only among the rDT isolates, which was associated with the smallest reduction in viability over time. The expression of Oct4 and NANOG were also higher among rDT isolates, however, expression was comparatively lower among the sDT isolates that had the highest reduction in cellular viability over the course of this study. These data may suggest that some biomarkers, including Sox-2, Oct4 and NANOG may have some potential for use as biomarkers that may be associated with either higher or lower cellular viability over long-term storage applications although more research will be needed to confirm these findings.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.551-559
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• 2004

Shiga toxin-producing Escherichia coli (STEC) causes various clinical signs in human and animals, and has been indicated as a global enteropathogen with zoonotic importance. In this study, the feces of healthy pigs were collected from the slaughtered pigs of Daejon abattoir during the period from December 2001 to October 2002. Of 326 specimens, 13 STEC were confirmed by culture, PCR and colony hybridization. The isolates were further studied for toxin types, pathogenic factors, plasmid profiles, and antimicrobial resistance to characterize the genetic and toxigenic properties. In PCR, all of 13 isolates were evident to have shiga toxin gene (stx). Of 13 isolates stx1 gene was detected in 4 and stx2 gene in 9. The genes of eaeA, hlyA and rfbE were not present in any isolates. In colony hybridization using shiga toxin common primer (STXc), 2 to 9 per 100 colonies subcultured from 13 isolates showed the positive reaction. In the examination for plasmid profiles of the isolates, one to eleven plasmids with varying sizes of 1.0 Kb to 100 Kb were detected, and the 13 STEC could be classified into four groups by the plasmid patterns. The antimicrobial resistance patterns of the isolates were comparably corresponded with the plasmid profile patterns.

• Journal of Microbiology
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• v.38 no.4
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• pp.265-269
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• 2000

Iron increased the susceptibilities of clinical isolates Pseudomonas aeruginosa to quinolones. In the presence of iron, increased susceptibilities to ofloxacin were observed in twenty-six out of thirty isolates and with no change in four isolates. In the case of norfloxacin, iran increased susceptibilities of twelve isolates but did not render any change in eighteen isolates. In the case of ciprofloxacin, iron decreased the MICs (Minimal Inhibitory Concentration) of twenty isolates, increased the MIC of one isolate, and did net change the MICs of nine isolates. To find out how iron increased susceptibility to ofloxacin, bacterial cells were grown in Muller Hinton (MH) media and succinate minimal media (SMM) to induce iran acquisition systems and the intracellular ofloxacin concentrations were assayed in the presence of iron. The addition of iron to the media decreased the MICs of cells whether they were grown in MH or SMM. Siderophores, carbonyl cyanide m-chlorophenylhydrazone (an inhibiter of proton motive force), and ouabain (an inhibitor of ATPase) did not decrease the effect of iron. Results suggested that the increase in the intracellular ofloxacin concentration by iron is accomplished not by decreasing the efflux but by increasing the of ofloxacin permeability.

• The Journal of the Korean Society for Microbiology
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• v.15 no.1
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• pp.33-38
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• 1980

Shigella remains to be an important enteric pathogen in this country for the moment. Moreover, since 1978, most of the isolates have become resistant to ampicillin and co-trimoxazole, which used to be the drugs of choice for shigellosis. Since a disc diffusion technique alone has been used in our routine susceptibility test, the minimum inhibitory concentrations(MIC) of both ampicillin and co-trimoxazole to Shigella have never been known. In order to determine these, 195 isolates were tested by an agar dilution method, all of which were isolated at Yonsei Medical Center during the period of June 1978 to July 1980. The following results were obtained. 1. Sixty cultures(29.7%) were susceptible to ampicillin, being the MIC of 8 ${\mu}g/ml$ or less and 53(27.2%) were susceptible to co-trimoxazole, being the MIC of TMP/SMZ 4/76 ${\mu}g/ml$ or less. S. flexneri type 2 was often resistant to both antimicrobic agents. 2. An increasing rate of resistant isolates was noted, particularly in the year of 1979. 3. Many isolates were resistant to both agents. Somewhat more cultures. were ampicillin susceptible and co-trimoxazole resistant than the other way around. It seems that the determination of species or even serotypes might be of help sometimes to select proper antimicrobic agent to control the infection. A routine antimicrobic susceptibility test of Shigella to both ampicillin and co-trimoxazole would be advisable for a better selection of chemotherapeutic agent.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.889-895
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• 2006

To investigate the antibiotic-resistant patterns and the gene types of extended-spectrum $\beta$-lactamase (ESBL)-producing Klebsiella pneumoniae, we collected 226 Klebsiella pneumoniae strains from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005, The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram-negative susceptibility (GNS) cards of Vitek (Vitek system, Hazelwood Inc., MO, U.S.A.). Of the 226 K, pneumoniae isolates, 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. TEM (Temoniera) type, SHV (sulfhydryl variable) type, and CTX-M (cefotaxime) type genes were detected by polymerase chain reaction. All 65 K. pneumoniae strains were resistant to ampicillin, cefazolin, cefepime, ceftriaxone, and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole, and 43.0% to gentamicin. TEM-type ESBLs (TEM-1 type, -52 type) were found in 64.6% (42 of 65) of the isolates, SHV-type ESBLs (SHV-2a type, -12 type, -28 type) in 70.7% (46 of 65) of isolates, and CTX-M-type ESBLS (CTX-M-15 type) in 45% (29 of 65) of isolates. Of the 65 ESBL-producing K. pneumoniae strains, two strains were found to harbor blaSHV-28, which were detected in Korea for the first time. Therefore, more investigation and research on SHV-28 are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosporin antibiotics.

• Pediatric Infection and Vaccine
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• v.3 no.1
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• pp.76-85
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• 1996

Adenoviruses(Ad) are considered to be second only to rotaviruses as the most significant cause of gastroenteritis in young children in Korea and thus it is essential to know the full spectrum of Ad serotypes routinely present in stool specimens from symptomatic patients. Sixty-six Ad isolates and three questionable ones collected over a 2-year peiord were typed by standard microneutralization, restriction endonuclease digestion and PCR of viral DNA to be able to evaluate these assays comprehensively for their ability to identify Ad associated with gastroenteritis. A total of sixty-one isolates(88.4%) were typed: the predominant types were Ad type 41(Ad41)(26.2%), Ad2(19.7%), Ad40(14.8%), Ad5(9.8%), and Ad7(9.8%) which together accounted for almost 80% of the isolates. The remaining virus isolates were typed as Ad1, 31, 34, 3, 25 and a mixture of 40/41. The incidence of Ad31(4.9%) or Ad3(1.6%) was relatively insignificant. DNA restriction analysis(77.5%) proved to be better than serum neutralization but not so when compared to a PCR-based assay for identification of the enteric Ad serotypes(90%) in stool specimens. In this work, the PCR-based assay was evaluated as a tool for the rapid, yet highly sensitive identification of adenoviral DNA sequences in fresh clinical stool specimens.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.751-759
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• 1999

Plaque characteristics of porcine reproductive and respiratory syndrome (PRRS) virus isolates were examined using MARC-145 line cells. The plaque morphology of PRRS virus isolates was variable in size and heterogenic in population. Upon serial passages of the PRRS virus isolates on MARC-145 tells, heterogeneity was maintained but numbers of the large plaque size virus were increased with certain isolates. A PRRS virus isolate with variable plaque sizes was subcloned into 2 populations : small plaque ($H_S$) and large plaque ($H_L$) viruses. Growth kinetics of the subclones were then determined in MARC-145 cells, and production of the structural polypeptides was analyzed by SDS-PAGE. In a comparison of the growth kinetics, the $H_S$ virus showed higher infectivity titers during the first 48 hours but slower to reach the peak titier than $H_L$ virus did. In a nucleotide sequence comparison, differences of 4 nucleotides in open reading frames 5-6 gene were found between $H_S$ and $H_L$ viruses. Both the $H_S$ and $H_L$ clones produced 5 polypeptide bands with molecular weights of 15, 19, 26, 36 and 42 kD. The 5 bands were detected at 48 hours postinoculation (PI) with antisera to $H_L$ and another large plaque virus ($W_L$) and at 72 hours PI with $H_S$ virus antiserum. The present results demonstrate differences of biologic and molecular characteristics between the two PRRS virus plaque clones.

• Journal of Life Science
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• v.21 no.6
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• pp.788-795
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• 2011

Accurate identification for pathogenic bacterium is an essential element in the clinical microbiology laboratory. We studied molecular analysis involving the identification of Chyseobacterium indologenes and evaluated the seventeen isolates in Korea with the 16S rRNA gene of the ribosome to estimate phylogenetic relationships within the genus Chyseobacterium in GenBank. The aligned data sets for C. indologenes were 1,176 nucleotides. Sequence variation within the C. indologenes was mostly due to nucleotide substitutions. Korean C. indologenes isolates were not strikingly different from the same species found in the other countries. However, the rates of base substitution in Korean C. indologenes isolates were higher than those of other C. indologenes isolates in GenBank. C. indologenes was placed as a sister species to C. isbiliense, C. hominis, C. hispanicum, C. molle, C. hungaricum, and C. pallidum.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.132-138
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• 2013

Acinetobacter baumannii is gram-negative bacilli that can be widely found in environments. Recently, A. baumannii emerged as a serious nosocomial infection. A total of 92 A. baumannii were isolated from hospitalized patients in Seoul, Korea, between December 2010 and April 2011. Antimicrobial susceptibility testing was investigated using CLSI agar dilution methods. Tigecycline non-susceptible A. baumannii isolates were investigated by repetitive extragenic palindromic sequence-based PCR (rep-PCR). Pulsed-field gel electrophoresis was performed to determine the epidemiological relationships. All clinical isolates showed high-level resistance to the most commonly used antibiotics: Ciprofloxacin (87.0%), Ampicillin/sulbactam (82.6%), Cefotaxime (81.5%), Ceftazidime (80.4%). Moreover, 50.0% of these isolates were non-susceptible to tigecycline. When evaluated by RAPD analysis, generated distinct band ranging in size from 1kb to 8k band varying from 4 to 10 bands. Stricter surveillance and more rapid detection are essential to prevent the spread of multi drug resistant A. baumannii.