Metallo-beta-Lactamase-Producing Pseudomonas spp. in Korea: High Prevalence of Isolates with VIM-2 Type and Emergence of Isolates with IMP-1 Type

PURPOSE: Two Korean nationwide studies showed that metallo-beta-lactamases (MBLs)-producing-Pseudomonas spp. are not rare. The aim of this study was to assess the trends of MBL-producing isolates among imipenem-resistant isolates of Pseudomonas spp. MATERIALS AND METHODS: Imipenem-resistant clinical isolates were collected from 23 hospitals and one commercial laboratory participating in the KONSAR program in 2005. Polymerase chain reaction (PCR) was used to detect MBL genes. RESULTS: Alleles of MBL genes were detected in 10.8% of 415 Pseudomonas aeruginosa and 66.7% of 12 P. putida isolates from 18 of 24 hospitals/laboratory. Among the 14 IMP-1-like and 39 VIM-2-like MBLs, emergence of IMP-6 was detected for the first time. CONCLUSION: Prevalence of MBL-producing P. aeruginosa has not significantly increased, but IMP-6 emerged in P. aeruginosa.

Misidentification as Vibrio alginolyticus with Vitek GNI+ Card in Three Cases / 대한임상미생물학회지

The introduction of a new, fully automated system into the clinical microbiology laboratory contributes to a rapid identification of microorganisms with accurate and reliable results, but such a system requires a high cost and additional tests for identification of some species. For instance, additional tests on oxidase, indole, motility, hemolysis, and pigmentation are needed in the correct identification by using Vitek GNI+ system (bioMerieux Vitek Inc., MO, USA). In particular, Vibrio and Aeromonas species are occasionally identified incorrectly when an automated system is used, and thus conventional biochemical tests may be more reliable in the identification of such species. We experienced three cases of incorrect identification of Vibrio parahaemolyticus, Vibrio cholerae, and Aeromonas veronii biovar sobria as Vibrio alginolyticus by using Vitek GNI+ card.

Increasing Prevalence of Vancomycin-Resistant Enterococci, and Cefoxitin-, Imipenem- and Fluoroquinolone-Resistant Gram-Negative Bacilli: A KONSAR Study in 2002

Continued antimicrobial resistance surveillance can provide valuable information for the empirical selection of antimicrobial agents for patient treatment, and for resistance control. In this 6th annual study for 2002, the susceptibility data at 39 Korean Nationwide Surveillance of Antimicrobial Resistance (KONSAR) hospitals were analyzed. Resistance rates of S. aureus were 67% to oxacillin, and 58% to clindamycin. The ampicillin and vancomycin resistance rates of E. faecium were 89% and 16%, respectively. To penicillin, 71% of S. pneumoniae were nonsusceptible. Resistance rates of E. coli were 11% to cefotaxime, 8% to cefoxitin, and 34% to fluoroquinolone, and those of K. pneumoniae were 22% to ceftazidime, and 16% to cefoxitin. Lowest resistance rates to cephalosporins shown by E. cloacae and S. marcescens were to cefepime, 7% and 17%, respectively. This is the first KONSAR surveillance, which detected imipenem-resistant E. coli and K. pneumoniae. To imipenem, 22% of P. aeruginosa and 9% of Acinetobacter spp. were resistant. Trends of resistances showed a slight reduction in MRSA and in penicillin- nonsusceptible S. pneumoniae, but an increase in ampicillin-resistant E. faecium. Ampicillin-resistant E. coli and H. influenzae remained prevalent. Compared to the previous study, amikacin- and fluoroquinolone- resistant Acinetobacter spp. increased to 60% and 62%, respectively. Ceftazidime- resistant K. pneumoniae decreased slightly, and imipenem- resistant P. aeruginosa and Acinetobacter spp., and vancomycin-resistant E. faecium increased. In conclusion, vancomycin-resistant E. faecium, cefoxitin-resistant E. coli and K. pneumoniae, and imipenem-resistant P. aeruginosa and Acinetobacter spp. increased gradually, and imipenem- resistant E. coli and K. pneumoniae appeared for the first time. Continued surveillance is required to prevent further spread of these serious resistances.

Korean Nationwide Surveillance of Antimicrobial Resistance in 2000 with Special Reference to Vancomycin Resistance in Enterococci, and Expanded-Spectrum Cephalosporin and Imipenem Resistance in Gram-Negative Bacilli

Antimicrobial resistance surveillance is necessary to determine the size of the problem and to guide empirical selection of antimicrobial agents for treating infected patients. The aim of this study was to analyze the results of susceptibility tests performed by hospitals participating in the Korean Nationwide Surveillance of Antimicrobial Resistance (KONSAR) program. The rates of oxacillin-resistant staphylococci, penicillin-nonsusceptible pneumococci, and ampicillin-resistant E. faecium were over 70%. Ampicillin-resistant H. influenzae increased to 68%. Expanded-spectrum cephalosporin-resistant K. pneumoniae, fluoroquinolone-resistant E. coli, and imipenem-resistant P. aeruginosa remained at 16% through 27%, depending on the species. The proportions of vancomycin-resistant E. faecium and imipenem-resistant P. aeruginosa were 18 - 24% and 19-21%, respectively, indicating the seriousness of antimicrobial resistance. In conclusion, the increasing prevalence of resistant bacteria indicates that more concerted effort is required to conserve the usefulness of precious new antimicrobial agents.

Estimation of Microalbuminuria by Urinary Albumin to Creatinine Concentration Ratio / 대한진단검사의학회지

BACKGROUND: Microalbuminuria is the main parameter used in diabetic patients for clinical evaluation of early diabetic nephropathy and other complications. The most common method for quantitative urinary protein relies on a 24-hour urine collection or overnight urine collection; however, this method is time consuming and sometimes obtains inaccurate results. This study is aimed to test whether the microalbumin to creatinine ratio (Uma/Ucr) in the first-morning urine samples correlates with the microalbumin content in the 24-hour urine collection. METHODS: 59 urine samples from 59 type 2 diabetic patients were analyzed for Uma/Ucr, and for 24-hour urine microalbumin that were successively collected. RESULTS: Daily microalbumin excretion varied from 2.4 to 168.7 mg/24 hr with a median value of 22.9 mg, and Uma/Ucr ranged from 3.4 to 200 g/mg with a median value of 29.0 g/mg. An excellent correlation was found between the microalbumin excretion measured from the 24-hour urine collections and the first-morning urine Uma/Ucr ratio (R=0.93, P<0.001). All patients that excreted more than 30 mg albumin in the 24-hour urine samples also had an Uma/Ucr of more than 30 g/mg. Patients who had less than 30 g/mg of Uma/Ucr were unlikely candidates for microalbuminuria. CONCLUSIONS: This study indicates that measurements of Uma/Ucr in first-morning urine samples are a simple and reliable alternative to measurements of the urinary albumin excretion rate in the 24-hour urine collections.

A Moderate Case of Hemolytic Disease in a Newborn Caused by Anti-M Antibody / 대한임상병리학회지

Anti-M antibodies are usually assumed to be naturally occurring and to consist of immunoglobulin M reacting at 4degrees C. They are not usually considered to be clinically significant, however, many of them have an immunoglobulin G component reacting at 37degrees C and can be correlated with hemolytic disease of the newborn (HDN). We report a moderate case of HDN by anti-M. A 2-days old baby born from a mother with preeclampsia as a second pregnancy was admitted due to anemia, hyperbilirubinemia and hypoxic encephalopathy. The blood type of mother was AB, ccDEE, NN, and the blood type of baby was A, D+, and MN. Antibody screening and identification identified anti-M antibody which was strong reactive at 37degrees C albumin and antiglobulin phase in both baby's and her mother's serum. The direct antiglobulin test of baby's red blood cells was negative. The infant was transfused with group O red cells which have negative to trace reaction with her mother's serum in antiglobulin phase. Two days later, the hemoglobin level elevated from 6.7 g/dL to 15.9 g/dL falled to below 11 g/dL quite soon. After all, newborn died of cardiac arrest due to her basic disease at age of 49 days; metabolic acidosis and hypernatremia.

Clinical Usefulness of An Immunochromatographic Assay Based on 38 kDa Antigen for The Diagnosis of Active Tuberculosis / 대한임상병리학회지

BACKGROUND: To detect active tuberculosis, clinicians usually rely on several methods those are so limited. As the prevalence rate of tuberculosis is high in Korea, culture is not so very effective in clinical use. The polymerase chain reaction (PCR) featuring rapidness and high sensitivity offers low specificity and it requires high test cost, complicated skills, expensive equipment. This study attempted to determine if the immunochromatographic assay, intended to measure antibodies using 38 kDa antigens, is valuable as a new method to diagnose active tuberculosis, by comparing it with existing acid-fast stain (AFB stain) and PCR. METHODS: The sera were collected from 31 BCG-vaccinated healthy persons and 55 patients subjected to AFB stain and PCR who visited Pohang Hospital of Dongguk University or Kyungpook National University Hospital, and then kept at -20degrees C until experiment. Fifty-five patients subjected to AFB stain and PCR were composed of 24 active tuberculosis patients and 31 non-TB patients. The evaluation of active tuberculosis was based on clinical criteria. RESULTS: The detection rate of antibody by the immunochromatographic method accounted for 83% in the active TB group, and each 6% in both the non-TB group and the healthy control group. The sensitivities of AFB stain, PCR and immunochromatographic method accounted for 67%, 88% and 83%, respectively, the specificities for 94%, 86% and 94%, respectively, the positive predictive values for 89%, 84% and 91%, respectively, and the negative predictive values for 78%, 89% and 88%, respectively. CONCLUSIONS: This suggests that the immunochromatographic method can be used for the rapid diagnostic method of active tuberculosis in an area with high prevalence value of tuberculosis like Korea. In addition, the immunochromatographic method showed the sensitivity approximate to that of PCR, the same specificity as AFB stain, and a high positive and negative predictive values. So it was expected not only to be greatly helpful for the diagnosis of active tuberculosis but also to be more useful in clinical practices because of short examination time, no special equipment and skills required, and inexpensive examination.

Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997

Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.

A Case of Tularemia Caused by Francisella Tularensis / 대한임상병리학회지

Tularemia is a major laboratory acquired zoonoses caused by Francisella tularensis that have high virulence, and usually transmitted to humans from direct contact with infected wild animals like rabbits or insect vectors like ticks. Clinical tularemia can be divided with 6 major syndromes that are delineated by the mode of organism aquisition, in which ulceroglandular type is the most common. F. tularensis have 3 different biogroups which have homogeneous antigenecity, type A (biogroup tularensis), type B (biogroup palearctica) and biogroup novicida, and can be confirmed by serology most frequently. In the domestic area, there was no reports of tularemia in humans or presence of bacteria in the reservoirs. Authers experienced a case of tularemia which is suspected as F. tularensis type B, ulceroglandular type. A healthy 40-year-old man admitted the hospital for lymph node swelling in both axillary and upper arm area and for furuncles in both forearm and palm. He contacted with dead rabbit and eated it after cooking before 20 days from admission day. In laboratory cultures, F. tularensis did not grow in any of the routine or anaerobic culture media except for one blood agar plate at 5 days. After subculturing that to cystine containing chocolate agar plate at 37C degree, 5% CO2 incubator, we could see the accelerating growth of colony. In microbiological test, it was oxidase and urease negative. In acid production in cystine trypticase agar base, it was glucose positive and sucrose, maltose, glycerol negative. In agglutinating test, F. tularensis antiserum titer (Difco, USA) with isolates was 1:160 or over and antibody titer to F. tularensis antigen (Difco, USA) was 1:320 or over. Anti-F. tularensis-IF assay and Anti-F. tularensis-indirect-EIA with isolates were positive.