• Korean Journal of Microbiology
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• v.48 no.4
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• pp.229-239
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• 2012

Cronobacter spp. (formerly Enterobacter sakazakii), a Gram-negative bacillus, is a rare cause of meningitis and central nervous system infections. In England, the first case infected by this organism occurred in 1958. By July 2008, approximately 120 documented cases of Cronobacter spp. infection and at least 27 deaths have been identified from all around the world in the published literature and in reports submitted by public health sectors. In 2007, it was proposed by European organizations that the original taxonomy of E. sakazakii would be revised, to consist of five new species moved to a new genus, and identified as "Cronobacter". E. sakazakii has thus now been reclassified as 6 separate species in the new genus, Cronobacter, gen. nov., within the Enterobacteriaceae family. The new species are presently Cronobacter sakazakii, C. turicensis, C. malonaticus, C. muytjensii, and C. dublinensis; the sixth species is identified simply as genomospecies I, as currently including only two representative strains. The objectives of this review are to provide insight on (1) the classification and taxonomy of Cronobacter spp., (2) its clinical etiology and pathogenicity, (3) prequency of Cronobacter spp. in different categories of ready-to-eat food other than infant formula, (4) methods for detecting, isolating and typing Cronobacter spp., and (5) recent research trends for detecting Cronobacter spp.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.590-593
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• 2011

Purpose: Surgical site infections (SSIs) are the third most frequently reported nosocomial infection. Of these SSIs, mostly were confined to the incision associated with underlying disease as diabetes, cigarette smoking, systemic steroid use, obesity, operating room environment, suture and surgical technique. This study has been planned to reduce the SSIs by using Vicryl $plus^{(R)}$ (Ethicon, USA) which contains triclosan, a broad-spectrum antibacterial agent, into the infected wound to evaluate whether or not Vicryl $plus^{(R)}$ (Ethicon, USA) is effective to nosocomial bacteria using a zone of inhibition assay. Methods: We did a comparison of Vicryl $plus^{(R)}$ suture (with triclosan) size 2-0, 5-0 with $Vicryl^{(R)}$ suture (without triclosan) size 4-0 each as treatment and control group, applied in Mueller-Hinton agar infected by following mircroorganisms: Methicillin-sensitive $Staphylococcus$ $aureus$ (MSSA), Methicillin-resistant $Staphylococcus$ $aureus$ (MRSA), Acinetobacter baumanii, $Escherichia$ $coli$, Enterobacter faecalis, Pseudomonas aeruginosa, Candida albicans. Cultures were made of the selected mircroorganisms, seeding the study strain in agar plates for 24 and 48-hour period in an oven at $37^{\circ}C$ followed by zone of inhibition assay. Results: Vicryl $plus^{(R)}$ group has demonstrated to create a zone of inhibition against MRSA, MSSA and $A.$ $baumanii$, but no effect on $E.$ $faecalis$, $P.$ $aeruginosa$, $C.$ $albicans$. Vicryl $plus^{(R)}$ suture size 2-0 also had antibactericidal effect while Vicryl $plus^{(R)}$ suture size 5-0 did not. $Vicryl^{(R)}$ group had no zones of inhibition showing colonization at all mircroorganisms. Conclusion: Our results seem to warrant the use of Vicryl $plus^{(R)}$ as absorbable buried suture when concerning SSIs as a prophylaxis against surgical nosocomial infection.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.104-110
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• 2004

To determine evolution and genotype of new chromosomal AmpC $\beta$-lactamases among clinical isolates of Enterobacter species, we performed antibiotic susceptibility testing, pI determination, sequencing, and phy-logenetic analysis using developed expression/secretion vector. Six isolates have shown to produce AmpC $\beta$-lactamases. Six genes of AmpC $\beta$-lactamases that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized in pMSG12119. Insert fragment containing the ampC genes was sequenced and found to have an open reading frame coding for 381-amino-acid $\beta$-lactamase. The nucleotide sequence of four ampC genes ($bla_EcloK992004.l$, $bla_EcloK995120.1$, $bla_EcloK99230$, and $bla_EareK9911729$) shared considerable homology with that of chromosomal ampC gene ($bla_EcloMHN1$) of E. cloacae MHN1 (more than 99.6% identity). The sequences of two ampC genes ($bla_EcloK9973$ and $bla_EcloK9914325$) showed close similarity to the chromosomal ampC gene ($bla_EcloQ908R$) of E. clo-acae 908R (99.7% identity). The results from phylogenetic analysis suggested that six ampC genes could be originated from $bla_EcloMHN1$ / or $bla_EcloQ908R$ / MIC patterns and exact pI values of six transformants indicated that the developed expression/secretion vector (pMSG1219) was suitable for the characterization of foreign genes in E. coli strain.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.51-59
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• 2017

It is to establish preliminary data about healthcare convergencr of infection control by performing a bacterial contamination test for CT scanner as well as general radiographic systems in the emergency rooms of general hospitals. The period was December 1 ~ December 31, 2015. It is detect in the emergency rooms of 7 medical facilities including 2 in Seoul, and 1 in Gyeonggi-do Province, and 2 in Jeonla-do Province, and 2 in Chungcheong-do Province. The surface contamination strains detected from CT scanner in the radiology department emergency rooms were Micrococcus species(4,5%), Stenotrophomonas maltophilia(9%), Enterococcus faecium(4.5%), Providencia stuartii(4.5), and Gram negative bacilli(4.5%). Also, the surface contamination strains detected from general radiographic system in the radiology department emergency rooms were Providencia stuartii(11%), Klebsiella pneumonia(3.5%), Stenotrophomonas maltophilia(11%), Pantoea species(11%), Acinetobacter baumannii(3.5%), Micrococcus species(3.5%), Escherichia coli(3.5%), Enterobacter species(3.5%), and Gram negative bacilli(11%). Considering that the regions of most detection were all the places closely related to patients, radiologists would have to thoroughly clean with alcohol before and after a test.

• Clinical and Experimental Pediatrics
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• v.54 no.2
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• pp.79-85
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• 2011

Purpose: We studied the differences in the antibiotic susceptibilities of the microorganisms that causeing urinary tract infections (UTI) in children to obtain useful information on appropriate drug selection for childhood UTI. Methods: We retrospectively analyzed the antibiotic susceptibilities of 429 microorganisms isolated from 900 patients diagnosed with UTI in the Department of Pediatrics, Chungbuk National University Hospital, from 2003 to 2008. Results: The most common causative microorganisms for UTI were Escherichia coli (81.4%), Klebsiella pneumoniae (8.4%), Enterobacter spp. (1.7%), and Proteus spp. (0.4%). E. coli showed relatively high susceptibility as compared to imipenem (100%), amikacin (97.7%), aztreonam (97.9%), cefepime (97.7%), and ceftriaxone (97.1%), while it showed relatively low susceptibility to gentamicin (GM) (79.0%), trimethoprim/sulfamethoxazole (TMP/SMX) (68.7%), ampicillin/sulbactam (33.0%), and ampicillin (AMP) (28.6%). There were no significant differences in the image findings for causative microorganisms. Conclusion: Gram-negative organisms showed high susceptibility to amikacin and third-generation cephalosporins, and low susceptibility to AMP, GM, and TMP/SMX. Therefore, the use of AMP or TMP/SMX as the first choice in empirical and prophylactic treatment of childhood UTI in Korea should be reconsidered and investigated further.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.215-220
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• 2014

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.30-35
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• 2010

Purpose : We investigated the causative organism and its antibiotic susceptibility of community acquired urinary tract infection (UTI) in children at a secondary hospital to test the adequacy of the current guidelines. Methods : Children diagnosed with UTI at the Department of Pediatrics, Kwandong University MyMyongji Hospital by pyuria and bacterial growth of greater than $1.0{\times}10^5CFU/mL$ on clean catch midstream urine from January 2005 to December 2008 were studied retrospectively. The epidemiologic data, causative organism, and the antibiotic susceptibility were analyzed. Results : Sixty two children were diagnosed with sixty four cases of UTI's. Two bacteria were isolated in one case and thus data on 65 urine cultures were analyzed. The male:female ratio was 1.6:1 and 78.1% were less than 12 months of age. Escherichia coli was the predominant cause consisting of 53 cases (82.8%) of the cases. K. pneumoniae (5), Enterobacter (4), Enterococcus (1), $\beta$-streptococcus (1), Diphtheroides (1) were isolated. The antibiotic resistance of E. coli were as follows; ampicillin 69.8%, cefotaxime 1.9%, gentamicin 15.1%, amikacin 0.0%, levofloxacin 1.9%, and trimethoprim/sulfamethoxazole 26.4 %. Only one case of the E. coli was extended spectrum $\beta$-lactamase (ESBL) positive. Conclusion : Compared to prior reports from other tertiary hospitals in Korea, E. coli was the predominant cause in childhood UTI and the rate of ESBL positivity was low. The antibiotic resistance was also different compared to prior reports. We conclude that a difference in the cause and antibiotic resistance of childhood UTI exists between centers and this should be taken into consideration when prescribing antibiotics for childhood UTIs.

• Neonatal Medicine
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• v.16 no.2
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• pp.172-181
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• 2009

Purpose: To identify trends in causative bacterial organisms for neonatal sepsis and antimicrobial susceptibilities over 10 years in one neonatal intensive care unit. Methods: We retrospectively reviewed the cases of culture-proven neonatal sepsis between January 1998 and December 2007. The 10-year period was divided into two phases (phase I, 1998-2002; phase II, 2003-2007) to distinguish the differences during the entire period. Results: Total 350 episodes of neonatal sepsis were identified in 315 neonates. The common pathogens of early-onset sepsis were S. epidermidis, S. aureus, P. aeruginosa, and E. cloacae in phase I, and S. epidermidis and E. cloacae in phase II. In cases of late-onset sepsis, coagulase negative Staphylococcus, S. aureus, and K. pneumoniae were isolated frequently in both phases. The incidence of sepsis caused by multi-drug resistant organisms decreased with strict infection control. Gram positive organisms showed 0-20% susceptibility to penicillin, ampicillin, and cefotaxime in both phases. Sensitivity to amikacin for Enterobacter spp. increased, whereas P. aeruginosa showed decreased sensitivity in phase II. Between 50% and 60% of other gram negative bacteria, except P. aeruginosa, were susceptible to cefotaxime in phase II in contrast to phase I. Greater than 80% of gram negative bacteria were sensitive to imipenem except P. aeruginosa and ciprofloxacin in both phases. Conclusion: The trend in causative microorganisms and antimicrobial susceptibilities can be used as a guideline for selection of appropriate antibiotics. A particular attention should be paid to infection control, especially to reduce sepsis caused by multi-drug resistant organisms.

• Journal of Yeungnam Medical Science
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• v.6 no.1
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• pp.59-68
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• 1989

Ceftizoxime sodium is a new synthetic ${\beta}$-lactam antibiotic combining potent antibacterial activity with high stability to a wide range of bacterial ${\beta}$-lactamase. This experiment was achieved to evaluate the antibacterial activities of ceftizoxime sodium againist Gram negative enteric bacteria isolated from in outpatient visiting Yeungnam university hospital and to study the emergence of drug induced bacterial varients which resist to ceftizoxime in vitro. The antibacterial activity of the ceftizoxime was compared with that of antibiotics and its effect on population of normal intestinal flora in mice was observed. The results are summarized as follows : 1. Highly effective antibacterial activity of ceftizoxime against Gram negative enteric bacilli was demonstrated and this antibacterial activity was superior to that of ampicillin. 2. Several test strains shows multiple antibiotic resistence. Among 15 strains of Escherichia coli, 1 strain was resistent to ampicillin, cefadroxyl, gentamicin, tetracycline, and 2 strains were resistent to ampicillin, cefadroxyl, tetracycline, five strains of Escherichia coli and Enterobacter cloacae was resistent to amplicillin, tetracycline and Shigella dysenteria was resistent to ampicillin, gentamicin, tetracycline. 3. The frequency of in vitro emergence of resistent varients among ceftizoxime sensitive bacteria in the presence of increasing concentrations of the compound was found to be low. 4. Plasmid was isolated in 6 of 9 strains (6 strains of Escherichia coli, Shigella dysenteriae, Enterobacter cloaceae and Salmonella typhi) That showed different antibiotic resistance. They were 5 strains of Escherichia coli and 1 strain of Shigella dysenteriae. However, plasmid could not be considered as a hallmark for antibiotic resistance by this. Further studies with curing experiment are to be accomplished for this purpose. 5. Changes in the bacterial count of normal intestinal flora following 25mg/kg/day administration of ceftizoxime over S consecutive days were not significant. In conclusion, ceftizoxime appeared to be a drug of choice in the treatment of Gram negative enteric bacilli infection.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.150-155
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• 2009

Purpose: To help the empirical antibiotics selection in diabetic foot infection patients, we investigated prevalence of microorganisms and their antibiotics sensitivity results. Materials and Methods: Patients who came to our clinics to treat diabetic foot infections with deep ulceration and were followed up more than 6 months until complete recovery were adopted. From March 2006 to June 2009, there were 140 patients who corresponded with such a inclusion criteria. Wound cultures were done by deep tissue or bone debris at first visit to our clinics. Microorganisms which was documented by wound culture and most susceptible antibiotics by minimum inhibitory concentrations were surveyed retrospectively. Results: Microorganisms were confirmed in 113 cases (80.7%). In the other 27 cases (19.3%), there were no cultured microorganisms. In bacterial growth group, there were 72 cases (63.7%) of gram-positive bacteria and 41 cases (36.3%) of gram-negative bacteria. All of them were aerobic microorganisms and there were no anaerobic microorganisms. Methicillin-sensitive staphylococcus aureus was the most common pathogen and accounted for 35 cases (31.0%). As other common pathogens, there were Enterobacter cloacae (11 cases, 9.7%), pseudomonas aeruginosa (10 cases, 8.8%), Methicillin-resistant staphylococcus aureus (10 cases, 8.8%) and enterococcus faecalis (6 cases, 5.3%), and so on. Common susceptible antibiotics in gram positive microorganism were vancomycin (60 cases, 83.3%), teicoplanin (60 cases, 83.3%), nitrofurantoin (60 cases, 83.3%) and ciprofloxacin (53 cases, 73.6%). In gram negative ones, common susceptible antibiotics were imipenem (35 cases, 85.3%), piperacillin/tazobactam (33 cases, 80.5%) and gentamicin (31 cases, 75.6%). Conclusion: Methicillin-sensitive Staphylococcus aureus in gram positive and enterobacter cloacae in gram negative was the most common pathogen in each group. Ciprofloxacin and gentamicin might be adaptable as a first-line empirical antibiotics in infected diabetic foot patients.