Increase in the Prevalence of Carbapenem-Resistant Acinetobacter Isolates and Ampicillin-Resistant Non-Typhoidal Salmonella Species in Korea: A KONSAR Study Conducted in 2011 / 감염과화학요법

BACKGROUND: Antimicrobial surveillance is important for providing an up-to-date understanding of the epidemiology of antimicrobial resistance and for creating a forum for rational drug development. In this study, we analyzed antimicrobial test data generated in 2011 by hospitals and commercial laboratories participating in the Korean Nationwide Surveillance of Antimicrobial Resistance program (KONSAR). MATERIALS AND METHODS: Data on the results of susceptibility tests conducted in 32 hospitals and two commercial laboratories were analyzed. Data on isolates from patients admitted to an intensive care unit (ICU) and those admitted to other wards were compared. Intermediate susceptibility was not analyzed and duplicate isolates were excluded. RESULTS: Escherichia coli was the most prevalent organism identified in both the hospital and commercial laboratories. Among the hospital isolates, methicillin-resistant Staphylococcus aureus (MRSA), penicillin G-non-susceptible Streptococcus pneumoniae, and ampicillin-resistant Enterococcus faecium remained as prevalent as they were in 2009. The proportion of vancomycin-resistant E. faecium (VR-EFM) slightly decreased from 29% in 2009 to 23% in 2011. Resistance rates of Klebsiella pneumoniae to ceftazidime, cefoxitin, fluoroquinolone, and amikacin were 24%, 14%, 27%, and 8%, respectively. Resistance rates of Pseudomonas aeruginosa to fluoroquinolone, ceftazidime, imipenem, and amikacin were 33%, 20%, 22%, and 16%, respectively, whereas those of Acinetobacter spp. resistance were 71%, 66%, 64, and 51%, respectively. The prevalence of oxyimino-cephalosporin-resistant E. coli and K. pneumoniae, carbapenem-resistant Acinetobacter spp. and P. aeruginosa, MRSA, and VR-EFM among ICU isolates was higher than those among non-ICU isolates. Extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae, imipenem-resistant P. aeruginosa, and VR-EFM were more prevalent among isolates from commercial laboratories than those from hospitals. Resistance rates of K. pneumoniae to ceftazidime and amikacin decreased from 32% and 24% in 2005 to 24% and 8% in 2011, respectively. The resistance rate of P. aeruginosa to amikacin decreased from 22% in 2005 to 16% in 2011. The proportion of imipenem-resistant Acinetobacter spp. increased from 16% in 2005 to 64% in 2011. CONCLUSIONS: The prevalence of MRSA, penicillin G-non-susceptible S. pneumoniae, and ampicillin-resistant E. faecium among clinical isolates tested in laboratories remained high. Multidrug resistance was more prevalent among isolates from ICUs. The prevalence of ceftazidime-resistant and amikacin-resistant K. pneumoniae and amikacin-resistant P. aeruginosa decreased after 2005, while the prevalence of imipenem-resistant Acinetobacter spp. increased.

Susceptibility of Escherichia coli from Community-Acquired Urinary Tract Infection to Fosfomycin, Nitrofurantoin, and Temocillin in Korea

With increase of multi-drug resistant Escherichia coli in community-acquired urinary tract infections (CA-UTI), other treatment option with a therapeutic efficacy and a low antibiotic selective pressure is necessary. In this study, we evaluated in vitro susceptibility of E. coli isolates from CA-UTI to fosfomycin (FM), nitrofurantoin (NI), temocillin (TMO) as well as trimethoprim-sulfamethoxazole (SMX), ciprofloxacin (CIP) and cefepime (FEP). The minimal inhibitory concentrations were determined by E-test or agar dilution method according to the Clinical and Laboratory Standards Institute guidelines, using 346 E. coli collected in 12 Korean hospitals from March 2010 to February 2011. FM, NI and TMO showed an excellent susceptibility profile; FM 100% (346/346), TMO 96.8% (335/346), and NI 99.4% (344/346). Conversely, resistance rates of CIP and SMX were 22% (76/346) and 29.2% (101/349), respectively. FEP still retained an activity of 98.5%. In Korea, NI and TMO in addition to FM are a good therapeutic option for uncomplicated CA-UTI, especially for lower UTI.

Susceptibility of Escherichia coli from Community-Acquired Urinary Tract Infection to Fosfomycin, Nitrofurantoin, and Temocillin in Korea

With increase of multi-drug resistant Escherichia coli in community-acquired urinary tract infections (CA-UTI), other treatment option with a therapeutic efficacy and a low antibiotic selective pressure is necessary. In this study, we evaluated in vitro susceptibility of E. coli isolates from CA-UTI to fosfomycin (FM), nitrofurantoin (NI), temocillin (TMO) as well as trimethoprim-sulfamethoxazole (SMX), ciprofloxacin (CIP) and cefepime (FEP). The minimal inhibitory concentrations were determined by E-test or agar dilution method according to the Clinical and Laboratory Standards Institute guidelines, using 346 E. coli collected in 12 Korean hospitals from March 2010 to February 2011. FM, NI and TMO showed an excellent susceptibility profile; FM 100% (346/346), TMO 96.8% (335/346), and NI 99.4% (344/346). Conversely, resistance rates of CIP and SMX were 22% (76/346) and 29.2% (101/349), respectively. FEP still retained an activity of 98.5%. In Korea, NI and TMO in addition to FM are a good therapeutic option for uncomplicated CA-UTI, especially for lower UTI.

Clinical and Microbiologic Characteristics of Clostridium difficile Infection Caused by Binary Toxin Producing Strain in Korea / 감염과화학요법

BACKGROUND: Binary toxin-producing Clostridium difficile infections (CDI) are known to be more severe and to cause higher case fatality rates than those by binary toxin-negative isolates. There has been few data of binary toxin-producing CDI in Korea. Objective of the study is to characterize clinical and microbiological trait of CDI cause by binary-toxin producing isolates in Korea. MATERIALS AND METHODS: From September 2008 through January 2010, clinical characteristics, medication history and treatment outcome of all the CDI patients were collected prospectively. Toxin characterization, PCR ribotyping and antibiotic susceptibility were performed with the stool isolates of C. difficile. RESULTS: During the period, CDI caused by 11binary toxin-producing isolates and 105 toxin A & toxin B-positive binary toxin-negative isolates were identified. Comparing the disease severity and clinical findings between two groups, leukocytosis and mucoid stool were more frequently observed in patients with binary toxin-positive isolates (OR: 5.2, 95% CI: 1.1 to 25.4, P = 0.043; OR: 7.6, 95% CI: 1.6 to 35.6, P = 0.010, respectively), but clinical outcome of 2 groups did not show any difference. For the risk factors for acquisition of binary toxin-positive isolates, previous use of glycopeptides was the significant risk factor (OR: 6.2, 95% CI: 1.4 to 28.6, P = 0.019), but use of probiotics worked as an inhibitory factor (OR: 0.1, 95% CI: 0.0 to 0.8; P = 0.026). PCR ribotypes of binary toxinproducing C. difficile showed variable patterns: ribotype 130, 4 isolates; 027, 3 isolates; 267 and 122, 1 each isolate and unidentified C1, 2 isolates. All 11 binary toxin-positive isolates were highly susceptible to clindamycin, moxifloxacin, metronidazole, vancomycin and piperacillin-tazobactam, however, 1 of 11 of the isolates was resistant to rifaximin. CONCLUSIONS: Binary toxin-producing C. difficile infection was not common in Korea and those isolates showed diverse PCR ribotypes with high susceptibility to antimicrobial agents. Glycopeptide use was a risk factor for CDI by those isolates.

Evaluation of Automated Blood Culture System for Body Fluids Culture Other Than Blood / 대한임상미생물학회지

BACKGROUND: We investigated whether culture using an automated blood culture system enhances the recovery of bacteria and fungi from body fluids other than blood when compared to conventional solid media culture methods. METHODS: A total of 734 specimens [ascites (n=457), bile (n=5), CAPD (n=28), CSF (n=32), joint fluids (n=165), pericardial fluid (n=17), and pleural fluid (n=30)] were included in the study. Half of the volume of each specimen was inoculated directly into automated blood culture bottles (bioMeriux, Marcy-I'Etoile, France). The remaining volume was inoculated onto conventional solid media (sheep blood agar, chocolate agar, and phenylethyl alcohol agar) after centrifuging at 3,000 rpm for 10 min. RESULTS: Clinically significant microorganisms were isolated from 62 specimens (8.5%) by automated blood culture and 61 specimens (8.3%) by the conventional solid media culture (kappa index: 0.81, 95% confidence interval: 0.75~0.89). Contamination was observed in 11 (1.8%) of the automated blood culture specimens and 3 (0.4%) of the solid media culture specimens. The mean turnaround times of the automated blood cultures and the conventional solid media cultures were 3.7 and 2.8 days, respectively (P<0.0001). CONCLUSION: Compared with conventional culture methods, no improvement in the recovery of clinically significant microorganisms was noted with the use of the automated blood culture system for the culture of body fluids other than blood.

The Effect of Eradication of Methicillin-resistant Staphylococcus aureus from Neonatal Intensive Care unit by Aggressive Infection Control Measures : Isolation Program and the Use of Chlorhexidine / 대한주산의학회잡지

PURPOSE: The increasing incidence and mortality of Methicillin-resistant Staphylococcus aureus (MRSA) colonization or blood-stream infection is an important problem in neonatal intensive care unit (NICU). The aims of this study are to evaluate the effective eradication of MRSA through the aggressive isolation program with or without the use of 2% chlorhexidine-gluconate (CHG) and to investigate significant risk factors of MRSA colonization in NICU. METHODS: This study is a retrospective collected data among 414 neonates admitted to a NICU from June 1, 2007, through October 31, 2009. We divided the groups into 3 periods according to isolation program or the use of 2% CHG. RESULTS: The aggressive isolation program decreased the incidence of MRSA colonization and the additional use of 2% CHG has reduced much more the incidence of MRSA colonization and bacteremia. Days of hospitalization, use of central line, days of using central line, presence of respiratory distress syndrome (RDS) or bronchopulmonary dysplasia (BPD), isolation program, and isolation program + use of CHG were significant factors associated with MRSA colonization or bacteremia in univariate logistic regression analysis. Days of using central line and isolation program + use of CHG were significant after in multivariate logistic regression analysis. CONCLUSION: Hand hygiene, active MRSA surveillance culture, isolation, contact isolation, nursing/doctor cohorts and the use of 2% CHG as skin sterilizer were effective in eradicating to MRSA. The effort of shortening the days of using central line is also necessary.

Evaluation of ChromID MRSA for the Detection of Methicillin-resistant Staphylococcus aureus / 대한임상미생물학회지

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both nosocomial and community settings, and screening for a carrier is an important infection control practice in many hospitals. We evaluated the sensitivity and specificity of the ChromID MRSA assay (bioM?rieux, Marcy I'Etoile, France). METHODS: A total of 190 clinical samples were collected from the anterior nares of premature infants in a newborn intensive care unit (N-ICU). Equal volumes (100microliter) of the samples were inoculated on mannitol salt agar with oxacillin 6 mg/L (MSAO) and ChromID MRSA after emulsifying the screening swab in brain-heart Infusion broth with oxacillin 6 mg/L (BE). The specimens in BE were subcultured on ChromID MRSA after an overnight incubation. RESULTS: Twenty-one of 190 samples (11%) was positive for MRSA by BE. After a 24 h incubation, the sensitivity/specificity of MSAO was 52%/98% and that of ChromID MRSA was 62%/100%, and at 48 h, the sensitivity/specificity of MSAO was 62%/92% and that of ChromID MRSA was 81%/99%. CONCLUSION: ChromID MRSA is a useful selective medium for the rapid isolation and identification of MRSA.

Post-traumatic Infrapatellar Bursitis due to Mycobacterium fortuitum in an Immunocompetent Patient / 감염과화학요법

Mycobacterium fortuitum is a rare pathogen, frequently found in water, soil, animals and plant materials. It can cause infections involving skin, soft tissue and skeletal system after direct inoculation of the pathogen through surgical traumas, punctures and injections. We report a case of infrapatellar bursitis caused by M. fortuitum in an immunocompetent, 42-year-old female, which occurred after bicycle trauma. She experienced marked improvement after surgical excision and debridement of the wound site and antimicrobial therapy.

Post-traumatic Infrapatellar Bursitis due to Mycobacterium fortuitum in an Immunocompetent Patient / 감염과화학요법

Mycobacterium fortuitum is a rare pathogen, frequently found in water, soil, animals and plant materials. It can cause infections involving skin, soft tissue and skeletal system after direct inoculation of the pathogen through surgical traumas, punctures and injections. We report a case of infrapatellar bursitis caused by M. fortuitum in an immunocompetent, 42-year-old female, which occurred after bicycle trauma. She experienced marked improvement after surgical excision and debridement of the wound site and antimicrobial therapy.

Multicenter Surgical Site Infection Surveillance Study about Prosthetic Joint Replacement Surgery in 2006 / 병원감염관리

BACKGROUND: Surgical site infection (SSI) is generally considered second or third most important infection type in nosocomial infections. However, there are only a few national surveillances about surgical site infection and prophylactic antibiotics use. We performed the surveillance of surgical site infections and antibiotic use in joint replacement operation, which is difficult and costly to treat. METHODS: The surveillance study of the hip joint (HRA) and knee joint replacement surgery (KRA) was performed in four university hospitals from July 2006 to December 2006. The Clinical variables, operative risk factors for SSI, and information of prophylactic antibiotics uses were evaluated. SSI surveillance was done in 2 weeks, 1 month, 3 month, 6 month, and 1 year after surgery. RESULTS: A total of 436 cases (HRA, 227; KRA, 209) were enrolled for SSI surveillance. The SSI rates of HRA and KRA were 1.32 (3/227), and 1.44 (3/209) per 100 operations, respectively. The most of operation site was clean wound (97.9%). Staphylococcus aureus was observed in 19.8% before operation and among S. aureus infections about 20% was methicillin-resistant strain. The 1st generation cephalosporins were most frequently used for prophyaxis occupying 65.1%. The median duration of antibiotic use was 12 days (1-79 days). Any other specific risk factors were not correlated with SSI development. CONCLUSION: The multicenter surveillance study of SSI was first performed in Korea. The SSI rate was comparable with SSI reported in other country. We need to analyze the risk factors of SSI after collecting the data through further studies.

Chlamydia trachomatis Antibody in Fitz-Hugh-Curtis Syndrome / 대한진단검사의학회지

BACKGROUND: Fitz-Hugh-Curtis (FHC) syndrome is inflammation of the liver capsule associated with pelvic inflammatory disease. We measured Chlamydia trachomatis antibodies in 30 female patients with acute abdominal pain for diagnosis of FHC-syndrome, and the results were compared with other tests. METHODS: A dual-polymerase chain reaction was used for the detection of C. trachomatis in the cervix, and a micro-immunofluorescence test was performed to measure the antibody to C. trachomatis in serum. Cervical specimens were stained with Gram stain and cultured on chocolate agar for detection of Neisseria gonorrhoeae, and abdominal computed tomography (CT) and pelvic examinations were performed. RESULTS: Of the 30 patients examined, 19 were diagnosed as having FHC-syndromes and 11 abdominal pains without FHC-syndrome. C. trachomatis was detected from one of the five patients studied, and no N. gonorrhoeae was isolated from the patients with FHC-syndrome. High titers of IgG antibody (1:512-1:1,024) to C. trachomatis were demonstrated in all patients with FHC-syndrome. The CT scan revealed perihepatitis in 14 patients with FHC-syndrome. CONCLUSIONS: All patients with FHC-syndrome are associated with C. trachomatis infections, and a high titer of C. trachomatis antibody (IgG) is a very useful marker for FHC-syndrome.

Korean Nosocomial Infections Surveillance System, Intensive Care Unit Module Report: Data Summary from July 2007 through June 2008 / 병원감염관리

BACKGROUND: This is the first annual data on the surveillance of intensive care unit (ICU) module by the Korean Nosocomial Infections Surveillance System (KONIS) from July 2007 through June 2008. METHODS: The KONIS performed a prospective surveillance for nosocomial urinary tract infections (UTI), bloodstream infections (BSI), and pneumonia (PNEU) at 96 ICUs in 56 hospitals. Nosocomial infection (NI) rates were calculated as the numbers of infections per 1,000 patient-days or device-days. RESULTS: A total of 2,637 NIs were found during the study period; 1,391 UTIs (1,365 cases were urinary catheter-associated), 667 BSIs (563 were central line-associated), and 579 PNEUs (357 were ventilator-associated). The rate of urinary catheter-associated UTIs was 4.43 cases per 1,000 device-days (95% confidence interval, 4.20-4.67) and urinary catheter utilization ratio was 0.84 (0.839-0.841). The rate of central line-associated BSIs was 2.83 (2.61-3.07) and the utilization ratio was 0.54 (0.538-0.542). The rate of ventilator-associated PNEUs was 2.49 (2.25-2.76) and the utilization ratio was 0.39 (0.388-0.392). Although the ventilator utilization ratios were lower in the hospitals with less than 900 beds than in the hospitals with more than 900 beds, the rates of ventilator-associated PNEUs were higher in the smaller hospitals than in the larger ones. CONCLUSION: This result suggests that ongoing targeted surveillance and implementation of proven infection control strategies are needed.

Rapid Screening of Vancomycin Resistant Enterococci with Chromogenic Agar (ChromID VRE) / 병원감염관리

BACKGROUND: Rapid screening of vancomycin-resistant enterococci (VRE) is very important for controlling and preventing the spread of VRE in hospitals. We compared the performance characteristics of a chromogenic agar (ChromID VRE, bioMerieux, France: CA) to that of Enterococcosel agar (supplemented with 6 microgram/mL of vancomycin :EA) for direct detection of VRE from stool swabs. METHODS: Total 125 rectal swabs were collected from 57 patients in the intensive care units of an 850-bed university hospital over a period of 3 months. The samples were inoculated on EA, CA and into broth enrichment containing 6 microgram/mL of vancomycin (BE). BE was subcultured on CA after overnight incubation. RESULTS: Eighty two samples from 22 patients were positive for VRE by BE. At 24 h, the sensitivity/specificity of EA and CA were 89%/100% and 72%/100%, respectively. At 48 h, the sensitivity/specificity of EA and CA were 94%/89% and 89%/100%, respectively. CONCLUSION: CA provides equivalent sensitivity comparable to EA for the recovery of VRE at 48 h incubation, and has additional advantage of being able to differentiate between vancomycine resistant E. faecium and E. faecalis.

Evaluation of the VIDAS CDAB Kits for the Detection of the Clostridium difficile Toxins A and B / 대한임상미생물학회지

BACKGROUND: Since the emergence of variant Clostridium difficile strains that fail to produce detectable toxin A, diagnostic kits targeted to detect toxin A only showed a considerable rate of false negative results. The aim of this study was to evaluate a toxins A and B (toxins A/B) detection kit recently marketed in Korea, and to compare toxin positive rates before and after introduction of the new kit. METHODS: The results of 5,783 toxin A assays performed during the 7-year period from 2001 through 2007 were analyzed and compared them to the toxins A/B assay data of 519 samples obtained from January to June 2008 in a university hospital. An enzyme-linked fluorescent immunoassay for toxins A/B (VIDAS C. difficile Toxin A & B, bioMerieux SA, France: VIDAS CDAB) and PCR for toxin genes A/B were performed directly in 102 stool samples from hospitalized patients. RESULTS: The positive rates of toxin A assays tended downward annually from 2001 to 2007 (16.3%, 17.8%, 13.9%, 11.4%, 13.8%, 8.2%, and 5.8%, respectively), but increased to 12.1% in 2008 after changing to the toxin A/B detection kit. The concordant rate of the VIDAS CDAB kit with the PCR method was 82.4%. Compared to the PCR method, the sensitivity and specificity of the toxin A/B kit were 60.7% and 90.5% respectively. CONCLUSION: Testing kits for C. difficile toxin A only could result in a misdiagnosis more frequently than the testing kit for toxins A/B. The sensitivity of the newly launched toxin A/B detection kit from bioMerieux SA needs to be improved, but it showed a good specificity

Antimicrobial Resistance of Clinically Important Bacteria Isolated from 12 Hospitals in Korea in 2005 and 2006 / 대한임상미생물학회지

BACKGROUND: Emergence and spread of antimicrobial resistant bacteria make it difficult to treat infections. A rapid increase in antimicrobial-resistant bacteria has become a serious problem in many countries including Korea, and it is important to perform a nationwide study of antimicrobial resistance to obtain some basic data that will help solve these problems. The aim of this study was to determine the nationwide prevalence of resistance among frequently isolated bacterial pathogens in 2005 and 2006 in Korea. METHODS: We collected routine susceptibility data for medically important bacterial pathogens from 12 university and general hospital laboratories in Korea from April to September in 2005 and from January to June in 2006. Collected data was analyzed by patient group. RESULTS: The proportions of methicillin-resistant Staphylococcus aureus (MRSA) were 65% in 2005 and 72% in 2006, respectively. The resistance rates of Enterococcus faecium to vancomycin were 29% in 2005 and 24% in 2006. The non-susceptible rates of Streptococcus pneumoniae to penicillin were 68% in 2005 and 74% in 2006. The resistant rates of Escherichia coli and Klebsiella pneumoniae to the 3rd generation cephalosporin were 10~12% and 25~39%, respectively, in 2005 and 11~15% and 30~34% in 2006. In Citrobacter freundii, Enterobacter cloacae and Serratia marcescens, the resistance rates to 3rd generation cephalosporin were 23~31%, 32~34%, and 17~27%, respectively, in 2005 and 21~37%, 37~43%, and 13~31% in 2006. The resistance rates to imipenem and meropenem were 21% and 18%, respectively, in Pseudomonas aeruginosa and 18% and 25% in Acinetobacter baumannii in 2005; 29% and 20% in P. aeruginosa and 18% and 23% in A. baumannii in 2006. Cotrimoxazole and levofloxacin resistance rates of Stenotrophomonas maltophilia were 5% and 13%, respectively, in 2005 and 3% and 7% in 2006. There were no isolates resistant to 3rd generation cephalosporin and fluoroquinolone among non-typhoidal Salmonella in 2005. CONCLUSION: Antimicrobial resistance of medically important bacteria is still a serious problem in Korea. To manage the problem, a continuous nationwide surveillance and diversified investigation and effort have become more important.

A Case of Intramuscular Abscess Caused by Nocardia farcinica in a Patient with Lupus Nephritis Concurrent with Pulmonary Tuberculosis / 대한류마티스학회지

Nocardiosis is usually a subacute infection, which can occur as an opportunistic infections in patients with systemic lupus erythematosus. There are rare cases of nocardiosis concurrent with Mycobacterium tuberculosis. We report a case of intramuscular nocardial abscess concurrent with pulmonary tuberculosis in a patient with lupus nephritis. She has received cyclophosphamide pulse therapies and is receiving oral steroid therapy 3 months ago. After Nocardia farcinica and Mycobacterium tuberculosis were confirmed by PCR and PCR-RFLP, we initiated trimethoprim/ sulfamethoxazole and antituberculous agents. After then, patient was improved and discharged, maintaining the medications.

Detection of Cytomegalovirus by Dual-PCR / 대한임상미생물학회지

BACKGROUND: Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in transplant recipients and immunocompromised patients. We compared the results of a dual polymerase chain reaction (dual-PCR) and an antigenemia (Ag) test for detection of CMV from blood samples. METHODS: Between February 2002 and May 2005, we analyzed 175 blood samples submitted for CMV tests at Hanyang University Hospital. The late antigen (LA) and major immediate early (MIE) genes of CMV were concurrently amplified in the dual-PCR. The lower matrix protein pp65 of CMV was detected for the Ag test (Chemicon, Temecula, CA, USA). RESULTS: The positive rate of the dual-PCR was 14.3% (25/175) and that of the Ag test was 13.1% (23/175). The concordance rate of the dual-PCR and Ag test was 85.1% (149/175), while the discordance rate was 14.9% (26/175). CONCLUSION: The dual-PCR is a useful method for the early detection of CMV, but we recommend using both the dual-PCR and Ag test for detection of CMV due to a high discordance rate of the two methods.

Emergence of CTX-M-12, PER-1 and OXA-30 beta-Lactamase-Producing Klebsiella pneumoniae / 대한임상미생물학회지

BACKGROUND: The aim of this study was to determine a nation-wide prevalence of Ambler class A and D extended-spectrum-lactamases (ESBL) in Klebsiella pneumoniae isolates in Korea. METHODS: During the period of April to May 2005, 189 isolates of K.pneumoniae were collected from 11 Korean hospitals. Antimicrobial susceptibilities to ceftazidime and cefotaxime were tested by the disk diffusion method, and ESBL production was determined by double-disk synergy test. Determinants of ceftazidime or cefotaxime-resistance were transferred to Escherichia coli J53 (azide-resistant) by transconjugation. Genotypes of class A and D ESBL genes were determined by PCR amplification and sequencing. RESULTS: One hundred-sixty isolates of K.pneumoniae showed positive results in double-disk synergy test. The most prevalent ESBL was SHV-12 (n=148). Also detected were genes encoding ESBLs including TEM-52 (n=1), SHV-2a (n=2), CTX-M-3 (n=15), CTX-M-9 (n=6), CTX-M-12 (n=2), CTX-M-14 (n=9), CTX-M-15 (n=1), PER-1 (n=1), GES-5 (n=3), and OXA-30 (n=2) beta-lactamases. CONCLUSION: With the emergence of CTX-M-12, PER-1, and OXA-30 beta-lactamases, the ESBLs in K.pneumoniae isolates are becoming more diverse in Korea.

G and P Genotyping of Human Rotavirus Isolated in a University Hospital in Korea: Implications for Nosocomial Infections

To characterize rotavirus G and P genotypes circulating among infants and young children hospitalized with severe diarrhea in a university hospital in Gyeonggi province, Korea, and to examine any association of the genotypes and nosocomial infections, we genotyped 103 isolates of rotavirus by multiplex RT-PCR. In July 2001-June 2002, we found that globally common strains constituted 64.2% (G2P[4] 28.3%, G3P[8] 28.3%, G4P[8] 5.7%, and G1P[8] 1.9%), and the uncommon strain, G4P[6], constituted 26.4%. During July 2002-June 2003, the percentage of common strains decreased to 44.0% (G3P[8] 18.0%, G2P[4] 16.8%, and G1P[8] 10.0%), but G4P[6] increased to 36.0%. G9P[8] was identified in 10.0% of cases, and thus can be considered an emerging strain in Korea. Eight-eight percent of G4P[6] was isolated from newborn babies. Among the 103 patients, there was an evidence of nosocomial rotavirus infection in 23 children (22.3%). Of these, 19 (82.6%) were newborns infected with G4P[6] strains of rotavirus. Most of the children who acquired rotavirus infection nosocomially showed symptoms of diarrhea, vomiting, fever, poor sucking, or dehydration, regardless of the genotype. This study revealed that G4P[6] has been the major genotype causing nosocomial rotavirus infection in our hospital.

G and P Genotyping of Human Rotavirus Isolated in a University Hospital in Korea: Implications for Nosocomial Infections

To characterize rotavirus G and P genotypes circulating among infants and young children hospitalized with severe diarrhea in a university hospital in Gyeonggi province, Korea, and to examine any association of the genotypes and nosocomial infections, we genotyped 103 isolates of rotavirus by multiplex RT-PCR. In July 2001-June 2002, we found that globally common strains constituted 64.2% (G2P[4] 28.3%, G3P[8] 28.3%, G4P[8] 5.7%, and G1P[8] 1.9%), and the uncommon strain, G4P[6], constituted 26.4%. During July 2002-June 2003, the percentage of common strains decreased to 44.0% (G3P[8] 18.0%, G2P[4] 16.8%, and G1P[8] 10.0%), but G4P[6] increased to 36.0%. G9P[8] was identified in 10.0% of cases, and thus can be considered an emerging strain in Korea. Eight-eight percent of G4P[6] was isolated from newborn babies. Among the 103 patients, there was an evidence of nosocomial rotavirus infection in 23 children (22.3%). Of these, 19 (82.6%) were newborns infected with G4P[6] strains of rotavirus. Most of the children who acquired rotavirus infection nosocomially showed symptoms of diarrhea, vomiting, fever, poor sucking, or dehydration, regardless of the genotype. This study revealed that G4P[6] has been the major genotype causing nosocomial rotavirus infection in our hospital.