The mental health of medical students in Daegu during the 2020 COVID-19 pandemic / 한국의학교육

Purpose@#In February 2020, the first outbreak of coronavirus disease 2019 (COVID-19) occurred in Daegu, South Korea, and confirmed cases increased sharply, sparking intense anxiety among residents. This study analyzed the data of a mental health survey on students enrolled at a medical school located in Daegu in 2020. @*Methods@#An online survey was administered to 654 medical school students (pre-medical course: 220 students, medical course: 434 students) from August to October 2020, with 61.16% (n=400) valid responses. The questionnaire included items about COVID-19-related experiences, stress, stress resilience, anxiety, and depression. @*Results@#Of the survey participants, 15.5% had experienced unbearable stress, with the most significant stress factors (in descending order) being limited leisure activities, unusual experiences related to COVID-19, and limited social activities. Approximately 28.8% reported psychological distress, and their most experienced negative emotions were helplessness, depression, and anxiety (in descending order). The mean Beck Anxiety Inventory and Beck Depression Inventory-II scores were 2.44 and 6.08, respectively, both within normal ranges. Approximately 8.3% had mild or greater anxiety, and 15% had mild or greater depression. For students under psychological distress, the experience of unbearable stress before COVID-19 affected anxiety (odds ratio [OR], 0.198; p<0.05), and having an underlying condition affected depression (OR, 0.190; p<0.05). With respect to their psychological distress during August–October 2020 compared with that during February–March 2020 (2 months from the initial outbreak), anxiety stayed the same while depression increased and resilience decreased at a statistically significant level. @*Conclusion@#It was found that some medical students were suffering from psychological difficulties related to COVID-19, and there were several risk factors for them. This finding suggests that medical schools need to not only develop academic management systems but also provide programs that can help students manage their mental health and emotions in preparation for an infectious disease pandemic.

Restoration of Immune Privilege in Human Dermal Papillae Controlling Epithelial-Mesenchymal Interactions in Hair Formation

BACKGROUND@#Hair follicles are among a handful of organs that exhibit immune privilege. Dysfunction of the hair follicle immune system underlies the development of inflammatory diseases, such as alopecia areata. @*METHODS@#Quantitative reverse transcription PCR and immunostaining was used to confirm the expression of major histocompatibility complex class I in human dermal papilla cells. Through transcriptomic analyses of human keratinocyte stem cells, major histocompatibility complex class I was identified as differentially expressed genes. Organ culture and patch assay were performed to assess the ability of WNT3a conditioned media to rescue immune privilege. Lastly, CD8? T cells were detected near the hair bulb in alopecia areata patients through immunohistochemistry. @*RESULTS@#Inflammatory factors such as tumor necrosis factor alpha and interferon gamma were verified to induce the expression of major histocompatibility complex class I proteins in dermal papilla cells. Additionally, loss of immune privilege of hair follicles was rescued following treatment with conditioned media from outer root sheath cells. Transcriptomic analyses found 58 up-regulated genes and 183 down-regulated genes related in MHC class I? cells. Using newborn hair patch assay, we demonstrated that WNT3a conditioned media with epidermal growth factor can restore hair growth. In alopecia areata patients, CD8? T cells were increased during the transition from mid-anagen to late catagen. @*CONCLUSION@#Identification of mechanisms governing epithelial and mesenchymal interactions of the hair follicle facilitates an improved understanding of the regulation of hair follicle immune privilege.

Use of Haloperidol and Lorazepam for Intractable Symptoms in the Hospice Palliative Care Unit

BACKGROUND: Terminally ill cancer patients suffer from refractory symptoms, and the last option of treatment is to consider sedatives. However, due to concerns that sedation may shorten survival time, some people prefer not to take sedatives. The purpose of this study was to investigate the effects of sedative administration on survival time among terminally ill cancer patients.METHODS: Two hundreds and thirty-seven patients who were hospitalized to the hospice care unit of public hospitals in Seoul from January, 2015 to March, 2016 were analyzed retrospectively. The univariate and multivariate Cox's proportional hazard regression model was used to determine independent factors related to survival time.RESULTS: The usage of sedation was necessary because the incidence of insomnia was 61.4% in the lorazepam only group, and the incidence of delirium was highest in the haloperidol group and the haloperidol with lorazepam group. Interestingly, multivariate analysis showed that male (HR, 1.766; P < 0.001), decreased consciousness (HR, 1.803; P=0.003), anorexia (HR, 1.506; P=0.012), resting dyspnea (HR, 1.757; P < 0.001), elevated serum bilirubin (HR, 1.657; P=0.001), and the haloperidol with lorazepam group (HR, 0.535, P < 0.001) were each significantly associated with survival time. Furthermore, patients in the haloperidol with lorazepam group survived longer than patients with no such medications.CONCLUSION: There is no evidence that treatment with sedative medication shortens the survival time of patients with terminally ill cancer with refractory symptoms.

Safety of Temporary Use of Recycled Autoclaved Femoral Components in Infected Total Knee Arthroplasty: Confirming Sterility Using a Sonication Method

BACKGROUND: The purpose of this study was to evaluate the usefulness of sonication technique for microbiological diagnosis and the sterility of the recycled autoclaved femoral components from infected total knee arthroplasty (TKA) using a sonication method. METHODS: Nineteen femoral implants explanted from patients with infected TKA were sterilized with a standard autoclave method. Standard culture of the fluid before and after sonication of the sterilized implants was performed to detect pathogenic microorganisms. Additional experiments were performed to evaluate the sterility of the recycled implant by inducing artificial biofilm formation. Methicillin-resistant Staphylococcus aureus (MRSA) was inoculated into 10 implants and sterilization in a standard autoclave was performed, and then the fluid was cultured before and after sonication. RESULTS: Two of the 19 sterilized implants were positive for growth of bacteria after sonication, whereas no growth was detected in the cultured fluid from the sterilized implants before sonication. The bacteria were Staphylococcus species in all two cases. In one of 10 implants inoculated with MRSA, the culture was positive for growth of bacteria both before and after sonication. However, Staphylococcus epidermidis was cultured from both occasions and thus this implant was thought to be contaminated. CONCLUSIONS: We found sonication for identification of pathogens could be helpful, but this finding should be interpreted carefully because of the possibility of contamination. Sterilization of an infected femoral implant with an autoclave method could be a good method for using the temporary articulating antibiotic spacer in two-stage revision arthroplasty.

The Experience of Paid Family-Care Workers of People with Dementia in South Korea

PURPOSE: The South Korean government introduced the universal long-term care insurance program in 2008 that created a new employment category of “paid family-care worker” to assist the elderly with chronic illnesses including dementia. The aim of this study was to understand the lived experience of paid family-care workers of people with dementia in South Korea. METHODS: The study was a qualitative research design underpinned by interpretive description principles involving eight paid family-care workers. The participants were recruited by attaching the advertisement flyer in a notice board of an educational facility for paid family-care workers. RESULTS: Paid family-care workers struggled to manage the behavioral and psychological symptoms of their care recipients. Their workloads created physical, emotional, social, and financial burdens. However, the care-giving activities were encouraged through their sense of responsibility, filial piety, and personal religious beliefs. Financial subsidies from the government and help received from others were also identified as encouragements. The education course provided to them assisted them to improve their dementia-care capabilities. CONCLUSION: Understanding paid family-care workers' lived experience in dementia care in South Korea assists with the identification of their educational needs and level of support they require to improve dementia care in the home care environment. A number of suggestions are made to increase paid family-care workers' knowledge, clinical skills, and job satisfaction to reduce their burdens and work-related incidents, such as challenging behaviors from those being cared for.

Factors Affecting Early School-Age Children's Subjective Happiness: Using the Actor-Partner Interdependence Model of Parental Variables

PURPOSE: The present study is a descriptive cross-sectional study of cause-and-effect relationship, which used the 7th year data of the Panel Study on Korean Children, to investigate the effects of parenting stress, depression, and family interactions of the parents of early school-age children on children's subjective happiness. METHODS: The present study included data of 1419 pairs of parents who participated in the mother and father survey of the Panel Study on Korean Children. The effects of parenting stress, depression, and parental family interactions on children's subjective happiness were analyzed as actor and partner effects using path analysis. RESULTS: Parenting stress had an actor effect on depression; maternal parenting stress (β=−.21, p < .001) and depression (β=−.30, p < .001) had an actor effect on maternal family interaction; and paternal parenting stress (β=−.18, p < .001) and depression (β=−.17, p < .001) had a partner effect on maternal family interaction. Paternal parenting stress was found to have an actor effect on paternal family interaction (β=−.30, p < .001), and parental depression was found to have actor effect (β=−.23, p < .001) and maternal depression had a partner effect on paternal family interactions (β=−.22, p < .001). Children's subjective happiness was found to have a statistically significant relationship with maternal family interaction (β=.40, p < .001). CONCLUSION: The significance of the study is in its provision of basic data for adjusting parents' family interactions that are closely related to the growth and development of children by confirming the effect of parents' parenting stress, depression, and family interaction on children's subjective happiness.

Antimicrobial Susceptibility and Characterization of Propionibacterium acnes by Multilocus Sequence Typing and Repetitive-Sequence-Based PCR

Propionibacterium acnes, a gram-positive, anaerobic, and aerotolerant bacterium that is found frequently in the skin as part of the human microbiome causes inflammatory acne, shoulder infection, and the contamination of medical devices. The study goals were the antibiotic resistant and molecular epidemiological characterization of the P. acnes isolates in Korea. A total of 22 P. acnes isolates originated from diverse patients were obtained from three National Culture Collections for Pathogens in South Korea. The hemolytic properties and minimum inhibitory concentrations (MIC) of five antibiotics (tetracycline, doxycycline, clindamycin, erythromycin, and minocycline) were determined. Only one isolate showed high MIC values and resistance to all five antibiotics. Genotypic characterization was achieved by multilocus sequence typing (MLST) for eight loci (aroE, guaA, tly, camp2, atpD, gmk, lepA, and sodA) and repetitive-sequence-based PCR (rep-PCR) analysis using the DiversiLab kit. MLST revealed four phylogroups that were type IA₁ (27.3%), type IA₂ (18.2%), type IB (13.6%), and type II (40.9%). Rep-PCR results demonstrated three clusters that were cluster I (39.1%), cluster II (45.5%), and cluster III (13.6%). The isolates of cluster I were part of phylogroup type IA (both IA₁ and IA₂), and the isolates of cluster II belonged to phylogroup type II. All isolates of phylogroup type IB were hemolytic and belonged to cluster III. The results of rep-PCR clustering analysis showed a good correlation with those of MLST phylogroups, suggesting that rep-PCR could be an alternative method to track P. acnes subtype lineages.

Detection of Bacterial Species in Chronic Periodontitis Tissues at Different Stages of Disease Severity

The goal of this research was to determine the relationship between the stage of chronic periodontitis and the presence of six bacterial pathogens (Aggregatibacter actinomycetemcomitans: AA, Fusobacterium nucleatum: FN, Porphyromonas gingivalis: PG, Prevotella intermedia: PI, Enterococcus faecalis: EF, and Parvimonas micra: PM). Forty-six chronic periodontitis patients visiting a dental hospital were included in this investigation. They were classified into four chronic periodontitis stages based on the sulcus bleeding index value and the probing depth. The tissue samples from the periodontal surgery were used for a direct PCR detection assay. A total of 49 samples from 46 patients were collected and classified into four chronic periodontitis groups (N: 6, P1: 13, P2: 18, P3: 12). The PCR assay showed that FN, PI, and PM were involved from the beginning of chronic periodontitis (P1), while AA and PG existed regardless of the disease stages. EF was strongly linked to the P3 stage of the disease. In order to assess the effect of dental treatments on patients with chronic periodontitis, EF should be a critical marker for P3 patients, while FN, PI, and PM would be good indicators for chronic periodontitis.

A Virulent Salmonella enterica Serovar Enteritidis Phage SE2 with a Strong Bacteriolytic Activity of Planktonic and Biofilmed Cells

Salmonella enterica serovar Enteritidis is one of the major food borne pathogens. Utilizing lytic bacteriophages against this pathogen can be a new and effective approach for the prevention of food-contamination and food-borne infection. In this study, we isolated and characterized a Salmonella Enteritidis specific lytic bacteriophage (phage SE2). The bacteriolytic activity of planktonic and biofilmed cells against an antibiotic resistant strain of Salmonella Enteritidis was also evaluated. Phage SE2 revealed an efficient bacteriolytic effect with biofilm dispersing ability and could maintain its virulence even at extreme pH and temperature. It can be a potential biotherapeutic agent against Salmonella Enteritidis.

The Effect of a Short-Term Family Psychoeducation Program for Schizophrenia on Family Burden and Emotions Towards Patients / 대한정신분열병학회지

OBJECTIVES: The aim of this study was to investigate continuously on how a short-term family psychoeducation program for schizophrenia would change the emotional stress and the knowledge of the family members. METHODS: Subjects were the family members who participated in the short-term family psychoeducation program for schizophrenia. The participants were asked to fill out self-reporting forms for 3 times-before commencing the 6-week family education, immediately after completing the program, and 3 months after completing the program respectively. RESULTS: A total of 46 subjects participated, and 20 of them responded to all questionnaires. Three months after the completion of psychoeducation, depression and anxiety subscale score among the General Health Questionnaire-28 decreased by 2.60 (p=0.04) and 2.20 (p=0.04) respectively. In caregiver burden criterion, the score decreased by 9.45 (p=0.04) in 3 months after completing the education. In knowledge about schizophrenia test, the score increased by 2.60 score (p<0.001), and this result was maintained after 3 months. CONCLUSION: It was found that a short-term family education program for schizophrenia was effective not only in improving the knowledge on the disease but also in reducing anxiety and depression, and this effect was maintained immediately after the psychoeducation and so was it as time passed as well.

A Case of Community-Acquired Methicillin-Resistant Staphylococcus aureus Pneumonia / 대한내과학회지

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has received considerable attention in recent years as the cause of infections in individuals in the community who do not have traditional risk factors for MRSA infection, such as hospitalization or contact with healthcare services. CA-MRSA strains have different molecular and antimicrobial susceptibilities, as compared to hospital-associated MRSA. Although CA-MRSA strains are primarily associated with skin and soft tissue infections, they can cause more invasive infections, such as severe community-acquired pneumonia. Reports on CA-MRSA pneumonia in Korea are sparse. Therefore, we report a case of CA-MRSA pneumonia with molecular typing of the MRSA isolate.

Thickness of Rectus Abdominis Muscle and Abdominal Subcutaneous Fat Tissue in Adult Women: Correlation with Age, Pregnancy, Laparotomy, and Body Mass Index

BACKGROUND: Rectus abdominis muscle and abdominal subcutaneous fat tissue are useful for reconstruction of the chest wall, and abdominal, vaginal, and perianal defects. Thus, preoperative evaluation of rectus abdominis muscle and abdominal subcutaneous fat tissue is important. This is a retrospective study that measured the thickness of rectus abdominis muscle and abdominal subcutaneous fat tissue using computed tomography (CT) and analyzed the correlation with the patients' age, gestational history, history of laparotomy, and body mass index (BMI). METHODS: A total of 545 adult women were studied. Rectus abdominis muscle and abdominal subcutaneous fat thicknesses were measured with abdominopelvic CT. The results were analyzed to determine if the thickness of the rectus abdominis muscle or subcutaneous fat tissue was significantly correlated with age, number of pregnancies, history of laparotomy, and BMI. RESULTS: Rectus abdominis muscle thicknesses were 9.58 mm (right) and 9.73 mm (left) at the xiphoid level and 10.26 mm (right) and 10.26 mm (left) at the umbilicus level. Subcutaneous fat thicknesses were 24.31 mm (right) and 23.39 mm (left). Rectus abdominismuscle thickness decreased with age and pregnancy. History of laparotomy had a significant negative correlation with rectus abdominis muscle thickness at the xiphoid level. Abdominal subcutaneous fat thickness had no correlation with age, number of pregnancies, or history of laparotomy. CONCLUSIONS: Age, gestational history, and history of laparotomy influenced rectus abdominis muscle thickness but did not influence abdominal subcutaneous fat thickness. These results are clinically valuable for planning a rectus abdominis muscle flap and safe elevation of muscle flap.

Bilateral Circular Xanthelasma Palpebrarum

No abstract available.

Dissemination of Plasmid-mediated qnr, aac(6')-Ib-cr, and qepA Genes Among 16S rRNA Methylase Producing Enterobacteriaceae in Korea

Plasmid-mediated quinolone resistance (PMQR) genes: qnr, aac(6')-Ib-cr, and qepA were investigated among 153 armA and 51 rmtB-positive transconjugants and their 204 clinical isolates of Enterobacteriaceae. Overall, qnrB4 and aac(6')-Ib-cr genes were identified in 52.3% (63 K. pneumoniae, 10 E. coli, 4 E. cloacae, and 3 E. aerogenes) and 24.8% (16 K. pneumoniae, 8 E. coli, 6 S. marcescens, 4 E. cloacae, 3 C. freundii and 1 K. oxytoca) of 153 armA-positive isolates, respectively. Four isolates of K. pneumoniae and two isolates of E. coli positive for armA co-harbored both qnrB4 and aac(6')-Ib-cr. The qepA gene was detected in 11.8% (5 E. coli and 1 K. pneumoniae) of 51 rmtB-positive clinical isolates and their transconjugants. Southern hybridization confirmed the co-localization of qepA and rmtB on a large conjugative plasmid of size between 90 to 170 kb. Inc replicon typing showed that qnrB4/6, aac(6')-Ib-cr, and qepA genes were principally disseminated by IncFIIAs, IncL/M, and IncF plasmids, respectively. This study constitutes the first report of the three known PMQR genes among the 16S rRNA methylase producing Enterobacteriaceae isolates of human origin from Korea.

Effect of Vitamin C, Silicon and Iron on Collagen Synthesis and Break-Down Enzyme Expression in the Human Dermal Fibroblast Cell (HS27)

Collagen is the major matrix protein in dermis and consists of proline and lysine, which are hydroxylated by prolyl hydroxylase (PH) and lysyl hydroxylase (LH) with cofactors such as vitamin C, oxygen, iron (Fe2+), ketoglutarate and silicon. The collagen degradation is regulated by matrix metalloproteinase-1 (MMP-1), of which is the major collagen-degrading proteinase whereas tissue inhibitors of metalloproteinase-1 (TIMP-1) bind to MMP-1 thereby inhibiting MMP-1 activity. In this study, we investigated the effects of vitamin C, silicon and iron on mRNA, protein expressions of PH, LH, MMP-1 and TIMP-1. The physiological concentrations of vitamin C (0-100 micrometer), silicon (0-50 micrometer) and iron (Fe2+:0-50 micrometer) were treated to human dermal fibroblast cells (HS27 cells) for 3 or 5days. The expression level of mRNA and protein was increased in not only PH but also LH when cells were incubated with vitamin C. A similar increase in LH mRNA or protein expression occurred when cells were incubated with silicon. Our results suggest that treatment of vitamin C and silicon increased mRNA and protein expression of PH and LH in human dermal fibroblast.

Antimicrobial Resistance and Multilocus Sequence Typing of Vancomycin-Resistant Enterococcus faecium Isolated from Clinical Specimens

A total of 58 vancomycin-resistant E. faecium (VREF) was isolated from 3 hospitals located in Daegu, Korea. The VREF isolates were evaluated for the antimicrobial susceptibility pattern and resistance determinants against vancomcin, aminoglycosides, and macrolides. The multilocus sequence types (MLST) were determined to characterize the clonal diversity of the VREF isolates. The VREF isolates were highly resistance to teicoplanin, erythromycin, ciprofloxacin, gentamicin, and streptomycin, whereas quinupristin-dalfopristin and linezolid were the most susceptible drugs. All isolates carried the vanA gene. The aac6'-aph2" (n=53) and aadE (n=27) genes were detected in the high-level aminoglycoside resistant (HLAR) isolates. The aac6'-aph2" gene was located in the conjugally transferable plasmids. The ermB and ermA genes were detected in the 54 and 3 VREF isolates, respectively. The VREF isolates showed 11 different sequence types (ST). The VREF isolates belonging to ST192 was the most prevalent (n=19), but detected in one hospital, whereas the isolates belonging to ST203 (n=11) were detected in 3 hospitals. These results suggest that the VREF isolates resistant to aminoglycosides and erythromycin are originated from different clones and specific VREF clones are spread in the study hospitals.

Genetic Diversity of Stenotrophomonas maltophilia Isolated from Clinical Specimens

Stenotrophomonas maltophilia is a multi-drug resistant pathogen that has been isolated with increasing frequency from the hospitalized patients. A total of 202 S. maltophilia was isolated from three university hospitals and analysed by molecular typing for an epidemiologic investigation. All isolates were tested by antimicrobial susceptibility, random amplified polymorphic DNA (RAPD) analysis, and pulsed-field gel electrophoresis (PFGE). The RAPD and PFGE patterns were recorded and analysed by the unweighted-pair group method with arithmetic average method. Two or more isolates were considered to be clonally related if their PFGE pattern exhibited > or =80% similarity. Trimethoprim/ sulfamethoxazole and ciprofloxacin were the most active antimicrobial agents tested. The majority of the isolates found to be genetically unrelated by PFGE. The genetically related isolates were recovered from the same patient. The result demonstrates a high genetic diversity of S. maltophilia isolates from clinical specimens. The clonal diversity of S. maltophilia from the hospitalized patients is partly due to the strains originated from the hospital environments, but not horizontal transfer between the patients

Ceramides and Cell Signaling Molecules in Psoriatic Epidermis: Reduced Levels of Ceramides, PKC-alpha, and JNK

Ceramides are the main lipids in the stratum corneum and are generated during cellular stress and apoptosis by de novo synthesis or by the action of sphingomyelinase. In addition, they are lipid second messengers produced by sphingolipid metabolism and trigger important cell responses, including protein kinase C-alpha (PKC-alpha) activation and the stimulation of signal transduction pathways with apoptosis and stress-activated protein kinases (SAPK), such as c-jun N-terminal kinase (JNK). Thus, ceramides have anti-proliferative and apoptotic effects. This study measured the changes in the levels of epidermal ceramides and ceramide-related apoptotic signaling molecules in psoriasis patients. Samples from lesional and non-lesional epidermis were obtained from psoriasis patients. Total ceramides were fractionated using thin-layer chromatography, and the levels of PKC-alpha and JNK expression were measured using Western blot analysis with specific antibodies. The ceramide level was reduced significantly, and this was associated with the downregulation of apoptotic signaling molecules, such as PKC-alpha and JNK, in the lesional epidermis of psoriasis patients. These results suggest that the decreased level of ceramides downregulates the apoptotic pathway, leading to epidermal proliferation in psoriasis.

Determination of Genomospecies and Characterization of Antimicrobial Resistance of Multi-drug Resistant Acinetobacter spp. Isolates

Acinetobacter species are non-fermentative Gram-negative coccobacilli and they have emerged as important nosocomial pathogens which are associated with the significant multidrug resistance in recent years. Carbapenem-resistant A. baumannii (CRAB) and pandrug-resistant A. baumannii (PDRAB) were reported in 1991 and 1998, respectively. Fiftyeight isolates of Acinetobacter species recovered from a university hospital between August 2004 and March 2005 were investigated for the existence of CRAB, PDRAB, extended-spectrum beta-lactamase (ESBL)-producing Acinetobacter and examined for their phenotypic and genotypic characteristics. Genomospecies of Acinetobacter species were determined by amplified rDNA restriction analysis (ARDRA) and antimicrobial susceptibility test was performed with 13 kinds of antimicrobial agents. Metallo-beta-lactamase (MBL) producers were screened by modified hodge test and confirmed by imipenem-EDTA disk synergy test. Detection of blaIMP-1, blaVIM-2, blaTEM, and blaPER-1 was performed by PCR. Genomic DNAs were analyzed by pulsed-field gel electrophoresis (PFGE). Among 58 isolates of Acinteobacter species, 40 isolates were identified as genospecies 2 (A. baumannii), 9 were 13TU, 5 were A. phenon 6/ct, and 4 were Acinetobacter genospecies 3 by ARDRA. Thirteen isolates were confirmed as MBL-producers and blaIMP-1 and blaVIM-2 were carried by 5 and 8 isolates of them, respectively. MBL-producers were mostly 13TU, A. phenon 6/ct 13TU, and Acinetobacter genospecies 3 and they were susceptible to ciprofloxacin and ampicillin-sulbactam. BlaPER-1 was carried by thirteen isolates and 12 isolates of them were PDRAB showing resistance to all antimicrobial agents tested, including ceftazidime, cefepime, aztreonam, ciprofloxacin, amikacin, gentamicin, ampicillin-sulbactam, and imipenem. In conclusion, most MBL-producers belonged to 13TU, A. phenon 6/ct 13TU, and Acinetobacter genospecies 3 which were susceptible to ciprofloxacin and ampicillin-sulbactam, whereas 12 of 13 PER-1-producers were PDRAB originated from the same clone.

Determination of Genomospecies and Characterization of Antimicrobial Resistance of Multi-drug Resistant Acinetobacter spp. Isolates

Acinetobacter species are non-fermentative Gram-negative coccobacilli and they have emerged as important nosocomial pathogens which are associated with the significant multidrug resistance in recent years. Carbapenem-resistant A. baumannii (CRAB) and pandrug-resistant A. baumannii (PDRAB) were reported in 1991 and 1998, respectively. Fiftyeight isolates of Acinetobacter species recovered from a university hospital between August 2004 and March 2005 were investigated for the existence of CRAB, PDRAB, extended-spectrum beta-lactamase (ESBL)-producing Acinetobacter and examined for their phenotypic and genotypic characteristics. Genomospecies of Acinetobacter species were determined by amplified rDNA restriction analysis (ARDRA) and antimicrobial susceptibility test was performed with 13 kinds of antimicrobial agents. Metallo-beta-lactamase (MBL) producers were screened by modified hodge test and confirmed by imipenem-EDTA disk synergy test. Detection of blaIMP-1, blaVIM-2, blaTEM, and blaPER-1 was performed by PCR. Genomic DNAs were analyzed by pulsed-field gel electrophoresis (PFGE). Among 58 isolates of Acinteobacter species, 40 isolates were identified as genospecies 2 (A. baumannii), 9 were 13TU, 5 were A. phenon 6/ct, and 4 were Acinetobacter genospecies 3 by ARDRA. Thirteen isolates were confirmed as MBL-producers and blaIMP-1 and blaVIM-2 were carried by 5 and 8 isolates of them, respectively. MBL-producers were mostly 13TU, A. phenon 6/ct 13TU, and Acinetobacter genospecies 3 and they were susceptible to ciprofloxacin and ampicillin-sulbactam. BlaPER-1 was carried by thirteen isolates and 12 isolates of them were PDRAB showing resistance to all antimicrobial agents tested, including ceftazidime, cefepime, aztreonam, ciprofloxacin, amikacin, gentamicin, ampicillin-sulbactam, and imipenem. In conclusion, most MBL-producers belonged to 13TU, A. phenon 6/ct 13TU, and Acinetobacter genospecies 3 which were susceptible to ciprofloxacin and ampicillin-sulbactam, whereas 12 of 13 PER-1-producers were PDRAB originated from the same clone.