Antimicrobial resistance surveillance of bacteria in 1999 in Korea with a special reference to resistance of enterococci to vancomycin and gram-negative bacilli to third generation cephalosporin, imipenem, and fluoroquinolone

Current status of multidrug-resistant bacteria

Background: The dissemination of multidrug-resistant (MDR) pathogen is of major public health concern as it leads to increased mortality rate, length of hospital stays, and medical expenses.Current Concepts: Korean Government enacted an Infectious Disease Control and Prevention Act in 2009, and 6 MDR bacteria including methicillin-resistant Staphylococcus aureus, vancomycin-resistant S. aureus (VRSA), vancomycin-resistant enterococci, multidrug-resistant Pseudomonas aeruginosa, multidrug-resistant Acinetobacter baumannii, and carbapenem-resistant Enterobacterales (CRE) have been legally declared as infectious diseases. According to the amendment of the Infectious Disease Control and Prevention Act in 2020, CRE and VRSA were classified as class 2 infectious diseases, and all cases of CRE and VRSA should be reported to the Korea Disease Control and Prevention Agency (KDCA). Methicillin-resistant S. aureus, vancomycin-resistant enterococci, multidrug-resistant P. aeruginosa, and multidrug-resistant A. baumannii were classified as class 4 infectious diseases, and cases that occur need to be monitored at KDCA-designated sentinel hospitals to prevent further dissemination.Discussion and Conclusion: In this review, the current antimicrobial resistance status of six types of MDR bacteria, legally declared as infectious diseases, was investigated.. The Korean government is operating national antimicrobial resistance surveillance systems such as the Korean Antimicrobial Resistance Monitoring System and Korean Global Antimicrobial Surveillance System, as a foundation for preventing the spread of antimicrobial resistance. Certain steps need to be taken, such as establishing a surveillance system for antimicrobial usages, strengthening antimicrobial stewardship and infection control systems, and developing new antimicrobials in order for us to achieve the national goal.

Phenotypic Detection of Extended Spectrum Beta lactamase and Carbapenemase Co-producing Clinical Isolates from Two Tertiary Hospitals in Kano, North West Nigeria

BACKGROUND

Continue rise in unprofessional use of antibiotics in our hospitals and communities is worrisome. A research study was therefore conducted to detect extended spectrum beta-lactamase (ESBL), carbapenemase, metallobeta lactamase and their co-production phenotypically from isolates obtained from patients admitted to or attending two tertiary hospitals in Kano, Nigeria.

METHOD

A total of 248 isolates of Escherichia coli and Klebsiella pneumoniaewere screened phenotypically for ESBL production and carbapenemase production according to CLS1 2012 breakpoints using double disk synergy test and modified Hodge test (MHT) respectively. Antibiotic susceptibility of the organisms was tested against colistin, tigecycline and 3 flouroquinolones.

RESULTS

The result shows that 58.0% of the isolates were ESBL producers with higher percentage in K. pneumoniae (62.9%). Further, about 40.3% and 36.6% of the isolates were resistant to meropenem and imipenem respectively. However, E. coli showed higher resistance to meropenem (47.1%) while K. pneumoniae showed higher resistance to imipenem (44.4%). Co-productions of carbapenemase and ESBL were observed in both E. coli and K. pneumoniae. Carbapenemase producing isolates were more obtained from uro-pathogens and wound isolates, with almost all the cases of co-production of the β lactamases occurring in urine and cathertips isolates. Overall susceptibilities of the isolates to colistin and tigecycline were 64.6and70.0% respectively, but isolates were less susceptible to flouroquinolones.

CONCLUSION

The finding of the study therefore indicates that carbapenem resistance is mediated by carbapenemase production and or overproduction of ESBL coupled with reduced porins. Co-production of carbapenemase, MBLs and ESBLs by some of the isolates is worrisome. Susceptibility to colistin and tigecycline was still promising, but increasing resistance to flouroquinolones has been observed.

Carbapenem-resistant Enterobacteriaceae: Prevalence and Risk Factors in a Single Community-Based Hospital in Korea

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are Gram-negative bacteria with increasing prevalence of infection worldwide. In Korea, 25 cases of CPE isolates were reported by the Korea Centers for Disease Control and Prevention in 2011. Most CPE cases were detected mainly at tertiary referral hospitals. We analyzed the prevalence and risk factors for carbapenem-resistant Enterobacteriaceae (CRE) in a mid-sized community-based hospital in Korea.

MATERIALS AND METHODS

We retrospectively analyzed all consecutive episodes of Enterobacteriaceae in a mid-sized community-based hospital from January 2013 to February 2014. CRE was defined as organisms of Enterobacteriaceae showing decreased susceptibility to carbapenems. Risk factors for CRE were evaluated by a case-double control design. Carbapenemase was confirmed for CRE using a combined disc test.

RESULTS

During 229,710 patient-days, 2,510 Enterobacteriaceae isolates were obtained. A total of 41 (1.6%) CRE isolates were enrolled in the study period. Thirteen species (31.7%) were Enterobacter aerogenes, 8 (19.5%) Klebsiella pneumoniae, 5 (12.2%) Enterobacter cloacae, and 15 other species of Enterobacteriaceae, respectively. Among the 41 isolates, only one (2.4%) E. aerogenes isolate belonged to CPE. For evaluation of risk factors, a total of 111 patients were enrolled and this included 37 patients in the CRE group, 37 in control group I (identical species), and 37 in control group II (different species). Based on multivariate analysis, regularly visiting the outpatient clinic was a risk factor for CRE acquisition in the control group I (P = 0.003), while vascular catheter and Charlson comorbidity index score ≥ 3 were risk factors in control group II (P = 0.010 and 0.011, each). Patients with CRE were more likely to experience a reduced level of consciousness, use a vasopressor, be under intensive care, and suffer from acute kidney injury. However, CRE was not an independent predictor of mortality compared with both control groups.

CONCLUSION

In conclusion, the prevalence of CRE was higher than expected in a mid-sized community-based hospital in Korea. CRE should be considered when patients have a vascular catheter, high comorbidity score, and regular visits to the outpatient clinic. This study suggests the need for appropriate prevention efforts and constant attention to CRE infection control in a mid-sized community-based hospital.

Drug utilization review of mupirocin ointment in a Korean university-affiliated hospital

BACKGROUND/AIMS

Intranasal mupirocin and chlorhexidine bathing are candidate strategies to prevent healthcare-associated infections caused by methicillin-resistant Staphylococcus aureus (MRSA). In Korea, intranasal mupirocin is not available, and mupirocin ointment, an over-the-counter drug, has been used indiscriminately. Furthermore, because it is covered by health insurance, mupirocin is easy to prescribe within hospitals.

METHODS

We performed a mupirocin drug utilization review (DUR) within Hallym University Sacred Heart Hospital. Annual use of mupirocin was investigated between 2003 and 2013, and monthly consumption of mupirocin was assessed during the final 2-year period. The DUR focused on August 2012, the period of highest use of mupirocin. Also, we investigated trends in mupirocin resistance in MRSA between 2011 and 2013.

RESULTS

Annual consumption of mupirocin increased from 3,529 tubes in 2003 to 6,475 tubes in 2013. During August 2012, 817 tubes were prescribed to 598 patients; of these, 84.9% were prescribed to outpatients, and 77.6% at the dermatology department. The most common indication was prevention of skin infections (84.9%), and the ointment was combined with systemic antibiotics in 62.9% of cases. The average duration of systemic antibiotic administration was about 7.8 days. The rate of low-level mupirocin resistance in MRSA increased from 8.0% to 22.0%, and that of high-level mupirocin resistance increased from about 4.0% to about 7.5%.

CONCLUSIONS

Inappropriate use of mupirocin is prevalent. Considering the increase in resistance and the future application of intranasal mupirocin, prophylactic use of mupirocin in dermatology departments should be reconsidered.

Virulence attributes in Brazilian clinical isolates of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic human pathogen responsible for causing a huge variety of acute and chronic infections with significant levels of morbidity and mortality. Its success as a pathogen comes from its genetic/metabolic plasticity, intrinsic/acquired antimicrobial resistance, capacity to form biofilm and expression of numerous virulence factors. Herein, we have analyzed the genetic variability, antimicrobial susceptibility as well as the production of metallo-β-lactamases (MBLs) and virulence attributes (elastase, pyocyanin and biofilm) in 96 strains of P. aeruginosa isolated from different anatomical sites of patients attended at Brazilian hospitals. Our results revealed a great genetic variability, in which 86 distinct RAPD types (89.6% of polymorphisms) were detected. Regarding the susceptibility profile, 48 strains (50%) were resistant to the antimicrobials, as follows: 22.92% to the three tested antibiotics, 12.5% to both imipenem and meropenem, 11.46% to ceftazidime only, 2.08% to imipenem only and 1.04% to both ceftazidime and meropenem. Out of the 34 clinical strains of P. aeruginosa resistant to both imipenem and meropenem, 25 (73.53%) were MBL producers by phenotypic method while 12 (35.29%) were PCR positive for the MBL gene SPM-1. All P. aeruginosa strains produced pyocyanin, elastase and biofilm, although in different levels. Some associations were demonstrated among the susceptibility and/or production of these virulence traits with the anatomical site of strain isolation. For instance, almost all strains isolated from urine (85.71%) were resistant to the three antibiotics, while the vast majority of strains isolated from rectum (95%) and mouth (66.67%) were susceptible to all tested antibiotics. Urine isolates produced the highest pyocyanin concentration (20.15±5.65 μg/ml), while strains isolated from pleural secretion and mouth produced elevated elastase activity (1441.43±303.08 FAU) and biofilm formation (OD590 0.676±0.32), respectively. Also, MBL-positive strains produced robust biofilm compared to MBL-negative strains. Collectively, the production of site-dependent virulence factors can be highlighted as potential therapeutic targets for the treatment of infections caused by heterogeneous and resistant strains of P. aeruginosa.

Mutations in thegyrAandparCGenes in Ciprofloxacin-Resistant Clinical Isolates ofAcinetobacter baumanniiin Korea

Mutation with Ser-83-->Leu in gyrA gene was associated with the principal mutation for ciprofloxacin resistance in clinical isolates of Acinetobacter baumannii. Double mutation, Ser-83-->Leu in gyrA gene and Ser-80-->Leu in parC gene, was the most frequently detected among ciprofloxacin-resistant isolates. A novel mutation with Ser-80-->Trp in parC gene, in addition to mutation in gyrA gene, was associated with a high-level ciprofloxacin resistance. These results suggested that the presence of an additional mutation in the parC gene contributed to a higher-level of ciprofloxacin resistance than a single mutation in the gyrA gene (geometric mean MICs of ciprofloxacin, 44.1 versus 16 microg/ml, P < 0.05).

Four Year Trend of Carbapenem-Resistance in Newly Opened ICUs of a University-Affiliated Hospital of South Korea

Background

Carbapenem-resistance is rapidly evolving among the pathogenic microbes in intensive care units (ICUs). This study aimed to determine annual trend of carbapenem-resistance in the ICU for 4 years, since the opening of a university-affiliated hospital in South Korea.

Methods

From 2005 to 2008, microbial samples from consecutive 6,772 patients were screened in the ICU. Three hundred and ninety-seven patients (5.9%) and their first isolates of carbapenem-resistant pathogens were analyzed.

Results

The percentage of patients infected with carbapenem-resistant organisms increased constantly during the initial three years (2.3% in 2005, 6.2% in 2006, 7.8% in 2007), then it declined to 6.5% in 2008. Acute Physiology and Chronic Health Evaluation (APACHE) III score at admission was 58.0±23.5, the median length of the ICU stay was 37 days, and the mortality rate was 37.5%. The sampling sites were endotracheal suction (67%), catheterized urine (17%), wound (6%) and others (10%). Bacteria with carbapenem-resistance were Pseudomonas aeruginosa (247 isolates, 62%), Acinetobacter baumannii (117 isolates, 30%), Enterobacteriaceae (12 isolates, 3%), and others (21, 5%). Of note, peak isolation of carbapenem-resistant microorganisms in medical ICU was followed by the same epidemic at surgical ICU.

Conclusion

Taken together, carbapenem-resistant pathogens are of growing concern in the ICU.

Clinical features, risk factors and outcomes of bacteremia due to enterococci with high-level gentamicin resistance: comparison with bacteremia due to enterococci without high-level gentamicin resistance

High-level gentamicin resistance (HLGR) in enterococci has increased since the 1980s, but the clinical significance of the resistance and its impact on outcome have not been established. One hundred and thirty-six patients with bacteremia caused by enterococci with HLGR (HLGR group) were compared with 79 patients with bacteremia caused by enterococci without HLGR (non-HLGR group). Hematologic malignancy, neutropenia, Enterococcus faecium infection, nosocomial infection and monomicrobial bacteremia were more common in the HLGR group than the non-HLGR group, and APACHE II scores were also higher (P<0.05, in each case). Neutropenia, monomicrobial infection, stay in intensive care at culture, and use of 3rd generation cephalosporin, were independent risk factors for acquisition of HLGR enterococcal bacteremia. Fourteen-day and 30-day mortalities were higher in the HLGR group than the non-HLGR group in univariate analysis (37% vs. 15%, P=0.001; 50% vs. 22%, P<0.001). However, HLGR was not an independent risk factor for mortality due to enterococcal bacteremia in multivariate analysis. Therefore, HLGR enterococcal bacteremia is associated with more severe comorbid conditions and higher mortality than non-HLGR enterococcal bacteremia but the HLGR itself does not contribute significantly to mortality.

Outbreaks of imipenem resistant Acinetobacter baumannii producing OXA-23 beta-lactamase in a tertiary care hospital in Korea

PURPOSE

Since November 2006, imipenem-resistant Acinetobacter baumannii isolates have increased in Kyung Hee University Hospital in Seoul, Korea. The purpose of this study was to determine the genetic basis and molecular epidemiology of outbreak isolates.

MATERIALS AND METHODS

Forty-nine non-repetitive isolates of the 734 IRAB strains were investigated in order to determine their characteristics. The modified Hodge and the ethylenediaminetetraacetic acid (EDTA)-disk synergy test were performed for the screening of carbapenemase and metallo-beta-lactamase production. Multiplex polymerase chain reaction (PCR) assays were performed for the detection of genes encoding for OXA-23-like, OXA-24-like, OXA-58-like and OXA-51-like carbapenemase. Pulsed-field gel electrophoresis (PFGE) was performed for strain identification.

RESULTS

All isolates showed 100% resistance to ciprofloxacin and gentamicin, 97.9% resistance to cefepime, piperacillin/tazobactam, aztreonam, ceftazidime and piperacillin, 93.9% resistance to tobramycin and 57.1% resistance to amikacin. All of the 49 isolates (100%) showed positive results in the modified Hodge test and negative results in the EDTA-disk synergy test. They all (100%) possessed the encoding gene for an intrinsic OXA-51-like carbapenemase and an acquired OXA-23-like carbapenemase in the multiplex PCR assay. PFGE patterns revealed that all isolates were clonally related from A1 to A14.

CONCLUSION

It is concluded that all of the 49 IRAB isolates acquired resistance to imipenem by producing OXA-23 carbapenemase and they might have originated from a common source.

Global resistance trends and the potential impact on empirical therapy

Globally, antibiotic resistance continues to be an increasing problem. The emergence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and extended spectrum beta-lactamase-producing Enterobacteriaceae has seriously reduced the number of empirical agents suitable for selected indications. Increasing Gram-negative resistance has also negatively impacted the physician's alternatives when choosing adequate initial therapy; increased reliance on the carbapenem class as empirical agents has led to the emergence of multidrug resistance in non-enteric Gram-negative bacilli. There is a critical need for new, broad-spectrum alternatives to the currently available broad-spectrum agents.

[In vitro antimicrobial synergy against imipenem-resistant Acinetobacter baumannii]

BACKGROUND

Most imipenem-resistant Acinetobacter baumannii (IRAB) isolates are multiresistant, leaving few options for an effective antimicrobial therapy. We purposed to select possible candidates for the combinations of antimicrobials that are synergistic in vitro for inhibitory or bactericidal activities against IRAB and evaluate the usefulness of double disk synergy test (DDS) in predicting synergistic bactericidal activity.

METHODS

Fifty-five IRAB isolates recovered from patients during the period from August 1999 to November 2000 were tested for susceptibilities to amikacin, gentamicin, tobramycin, piperacillin, piperacillin/tazobactam, cefotaxime, cefepime, cefoperazone/sulbactam (C/S), imipenem, meropenem, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, minocycline, and colistin by the Clinical and Laboratory Standard Institute agar dilution method. Three isolates showing different susceptibility profiles were tested for antimicrobial synergy by DDS and then by timekill study (TKS) using DDS-positive combinations.

RESULTS

Colistin, C/S, and minocycline were active in 50 (90.9%), 50, and 44 (80.0%) isolates, respectively, and all the other drugs were active in less than 20% of isolates. Minocycline-imipenem, minocycline-C/S, minocycline-amikacin, imipenem-tobramycin, C/S-amikacin, and C/S-tobramycin combinations showed synergistic inhibitory or bactericidal activity by TKS when the same combinations were synergistic in DDS; however, C/S-imipenem was found synergistic on DDS, but not by TKS.

CONCLUSIONS

Colistin, C/S, and minocycline were relatively active against IRAB. DDS might help predict the synergistic antimicrobial effect of TKS if one of the combinations was susceptible.

Vancomycin-resistant enterococcal bacteremia in a hematology unit: molecular epidemiology and analysis of clinical course

An increase in vancomycin-resistant enterococcal (VRE) bacteremia in hemato-oncological patients (n=19) in our institution from 2000 through 2001 led us to analyze the molecular epidemiologic patterns and clinical features unique to our cases. The pulsed field gel electrophoresis of the isolates revealed that the bacteremia was not originated from a single clone but rather showed endemic pattern of diverse clones with small clusters. A different DNA pattern of blood and stool isolates from one patient suggested exogenous rather than endogenous route of infection. Enterococcus faecium carrying vanA gene was the causative pathogen in all cases. Patients with VRE bacteremia showed similar clinical courses compared with those with vancomycin-susceptible enterococcal (VSE) bacteremia. Vancomycin resistance did not seem to be a poor prognostic factor because of similar mortality (5/8, 62.5%) noted in VSE bacteremia. Initial disease severity and neutropenic status may be major determinants of prognosis in patients with VRE bacteraemia.

Pyogenic and amebic liver abscesses

Pyogenic and amebic liver abscesses are the two most common hepatic abscesses. Amebic abscesses are more common in areas where Entamoeba histolytica is endemic, whereas pyogenic abscesses are more common in developed countries. Pyogenic abscess severity is dependent on the bacterial source and the underlying condition of the patient. Amebic liver abscess is more prevalent in individuals with suppressed cell-mediated immunity, men, and younger people. The right lobe of the liver is the most likely site of infection in both types of hepatic abscess. Patients usually present with a combination of fever, right-upper-quadrant abdominal pain, and hepatomegaly. Jaundice is more common in the pyogenic abscess. The diagnosis is often delayed and is usually made through a combination of radiologic imaging and microbiologic, serologic, and percutaneous techniques. Treatment involves antibiotics along with percutaneous drainage or surgery.

Antimicrobial activities of garenoxacin (BMS 284756) against Asia-Pacific region clinical isolates from the SENTRY program, 1999 to 2001

Between 1999 and 2001, 16,731 isolates from the Asia-Pacific Region were tested in the SENTRY Program for susceptibility to six fluoroquinolones including garenoxacin. Garenoxacin was four- to eightfold less active against Enterobacteriaceae than ciprofloxacin, although both drugs inhibited similar percentages at 1 microg/ml. Garenoxacin was more active against gram-positive species than all other fluoroquinolones except gemifloxacin. For Staphylococcus aureus, oxacillin resistance was high in many participating countries (Japan, 67%; Taiwan, 60%; Hong Kong, 55%; Singapore, 52%), with corresponding high levels of ciprofloxacin resistance (57 to 99%) in oxacillin-resistant S. aureus (ORSA). Of the ciprofloxacin-resistant ORSA isolates, the garenoxacin MIC was >4 microg/ml for only 9% of them. For Streptococcus pneumoniae, penicillin nonsusceptibility and macrolide resistance were high in many countries. No relationship was seen between penicillin and garenoxacin susceptibility, with all isolates being susceptible at <2 microg/ml. There was, however, a partial correlation between ciprofloxacin and garenoxacin MICs. For ciprofloxacin-resistant isolates for which garenoxacin MICs were 0.25 to 1 microg/liter, mutations in both the ParC and GyrA regions of the quinolone resistance-determining region could be demonstrated. No mutations conferring high-level resistance were detected. Garenoxacin shows useful activity against a wide range of organisms from the Asia-Pacific region. In particular, it has good activity against S. aureus and S. pneumoniae, although there is evidence that low-level resistance is present in those organisms with ciprofloxacin resistance.

Detection of metallo β-lactamase production and antibiotic resistance with E-test method in pseudomonas, acinetobacter and klebsiella strains, in Turkey

The metallo beta-lactamase (MBL) mediated resistance patterns remain unknown in most countries. We aimed to investigate the existence and antimicrobial resistance of MBL-producing strains among carbapenem-resistant gram-negative bacteria that were isolated from nosocomial infections in patients in an university hospital in Turkey. Fifteen of 52 Pseudomonas aeruginosa strains (29%), 5 of 24 Acinetobacter baumanii strains (21%), and 2 of 2 Klebsiella pneumoniae strains (100%) were found to be metallo enzyme producers, with the Etest MBL technique. The in vitro antibiotic susceptibility of the MBL-positive organisms was investigated by the Etest method. Of the ten drugs tested, isepamicin was the most active agent against the MBL-producing strains. Overall, the rank order of activity of the ten antibiotics, in terms of the percentages of susceptible strains, was: isepamicin, 73%; ciprofloxacin, 64%; amikacin, 59%; aztreonam, 18%; tobramycin, 18%; meropenem, 14%; cefoperazone-sulbactam, 5%; piperacillin-tazobactam, 0%; ticarcillin-clavulanate, 0%; and cefepim, 0%. The meropenem minimum inhibitory concentrations (MICs) of the metallo enzyme-producing and nonproducing carbapenem-resistant strains were compared, and the MBL-producers were found to have higher meropenem MICs than the nonMBL-producing carbapenem-resistant strains. Early preventive measures should be taken against MBL-producing nosocomial pathogens that are associated with wide spread and high antimicrobial resistance.

VIM- and IMP-type metallo-beta-lactamase-producing Pseudomonas spp. and Acinetobacter spp. in Korean hospitals

We determined the occurrence of acquired metallo-β-lactamase (MBL)–producing bacteria in Korean hospitals. Among the isolates nonsusceptible to imipenem that were collected from 28 hospitals from 2000 to 2001, 44 (11.4%) of 387 Pseudomonas spp. and 38 (14.2%) of 267 Acinetobacter spp. infections produced MBL and had alleles of bla_VIM-2 or bla_IMP-1. MBL-producing isolates were detected in 60.7% of the hospitals.

Sudden increase of vancomycin-resistant enterococcal infections in a Korean tertiary care hospital: possible consequences of increased use of oral vancomycin

A sudden increase in vancomycin-resistant enterococci (VRE) infections was noted in 1998 in a tertiary care hospital in Korea. All of the VRE isolated in 1998 in the hospital were VanA type and most were multidrug-resistant Enterococcus faecium. The increase in VRE was probably due to the increased use of oral vancomycin to treat Clostridium difficile infections and clonal as well as horizontal spread. More restricted oral vancomycin use and stricter infection control measures are required to achieve a better control of the spread of VRE.

Nosocomial and ventilator-associated pneumonias: developing country perspective

Nosocomial pneumonias are recognized as an important cause of morbidity and mortality in industrialized nations. Emerging data show that they play a similar role in the developing world. A host of extrinsic and intrinsic factors predispose individuals to the development of pneumonias, and a modification of some of these factors provides a low cost solution to prevention of pneumonias. The ideal modality for microbiologic diagnosis of pneumonia remains to be determined. Recent data suggest that there is no difference in outcome when noninvasive techniques are compared with invasive techniques. Antimicrobial resistance is a rapidly increasing problem globally, and combating this with appropriate antibiotic policies, close surveillance, and physician education is essential.

A new integron carrying VIM-2 metallo-beta-lactamase gene cassette in a Serratia marcescens isolate

Serratia marcescens is an important nosocomial pathogen which is often resistant to multiple antimicrobial agents. An imipenem-resistant S. marcescens isolate from a urine specimen was found to carry a bla(VIM-2) gene cassette on a class 1 integron. This finding indicates that bla(VIM-2) is presently spreading even to Serratia spp. in Korea, which could compromise the usefulness of carbapenem in the treatment of multi-resistant Gram-negative bacilli infections. Clinical laboratory should be able to detect the VIM-2-producing isolates with even low carbapenem MIC.