INTRODUCTIONVancomycin-resistant enterococcus (VRE) can cause serious infections in vulnerable, immunocompromised patients.

MATERIALS AND METHODSIn this article, we summarise current data on epidemiology, detection, treatment and prevention of VRE.

RESULTSVRE was first isolated in Singapore in 1994 and until 2004 was only sporadically encountered in our public hospitals. After 2 outbreaks in 2004 and in 2005, VRE has become established in our healthcare institutions. Multiple studies have shown that VRE spreads mainly via contaminated hands, cloths and portable equipment carried by healthcare workers.

CONCLUSIONSOnly a comprehensive programme (consisting of active surveillance, isolation of colonised/infected patients, strict adherence to proper infection control practices and anti-microbial stewardship) can limit the spread of these organisms. In addition to monitoring the compliance with traditional infection control measures, new strategies that merit consideration include pre-emptive isolation of patients in high-risk units and molecular techniques for the detection of VRE.

Anti-Bacterial Agents ; pharmacology ; Disease Outbreaks ; Disease Transmission, Infectious ; prevention & control ; Enterococcus ; drug effects ; isolation & purification ; Gram-Positive Bacterial Infections ; microbiology ; prevention & control ; transmission ; Humans ; Infection Control ; methods ; Singapore ; Vancomycin ; pharmacology ; therapeutic use ; Vancomycin Resistance

Since its first isolation in 1997, vancomycin-intermediate Staphylococcus aureus (VISA) has been a clinical concern because it may lead to treatment failure. Up to the present, there were two reports of clinical VISA cases in Korea. We now report two additional cases of VISA with the minimum inhibitory concentration (MIC) of 4 microgram/mL. The first patient was a 59 yr-old man who had undergone total hip replacement arthroplasty in 1999 due to avascular necrosis of femur heads. He had recurrent episodes of infected hip caused by methicillin-resistant Staphylococcus aureus (MRSA) and was treated with vancomycin. He underwent replacement operation of prosthesis. Cultures of joint fluid and joint tissue grew S. aureus. Vancomycin MIC as determined by a broth microdilution method was 4 microgram/mL for the both isolates. The patient was treated with high enough doses of vancomycin to maintain serum trough concentrations at 20-25 microgram/mL for 52 days and was discharged. The second patient was a 57 yr-old man with diabetes. He lost consciousness from drinking. After recovery of consciousness, he was diagnosed with aspiration pneumonia. MRSA and Acinetobacter baumannii were cultured from sputum and the patient was treated with vancomycin and meropenem. During hospitalization, bed sores developed in his ankle and back. A wound culture from the sore grew S. aureus with vancomycin MIC of 4 microgram/mL. Since infection was localized, systemic antibiotics did not seem necessary, and the patient was transferred to another hospital for isolation and management.
Acinetobacter Infections/drug therapy ; Acinetobacter baumannii/isolation & purification ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Humans ; Joints/microbiology ; Male ; Methicillin-Resistant Staphylococcus aureus/*isolation & purification ; Microbial Sensitivity Tests ; Middle Aged ; Pressure Ulcer/microbiology ; Staphylococcal Infections/*drug therapy ; Thienamycins/pharmacology/therapeutic use ; Vancomycin/pharmacology/*therapeutic use ; *Vancomycin Resistance

Natural cyclopeptides are hot spots in chemical and pharmaceutical fields because of the wide spreading bio-resources, complex molecular structures and various bioactivities. Bio-producers of cyclopeptides distribute over almost every kingdom from bacteria to plants and animals. Many cyclopeptides contain non-coded amino acids and non-pepditic bonds. Most exciting characteristic of cyclopeptides is a range of interesting bioactivities such as antibiotics gramicidin-S (2), vancomycin (3) and daptomycin (4), immunosuppressive cyclosporin-A (1) and astin-C (8), and anti-tumor aplidine (5), RA-V (6) and RA-VII (7). Compounds 1-4 are being used in clinics; compounds 5-8 are in the stages of clinical trial or as a candidate for drug research. In this review, the progress in chemical and bioactive studies on these important natural bioactive cyclopeptides 1-8 are introduced, mainly including discovery, bioactivity, mechanism, QSAR and synthesis.
Animals ; Anti-Bacterial Agents ; chemical synthesis ; chemistry ; pharmacology ; Antineoplastic Agents ; chemical synthesis ; chemistry ; therapeutic use ; Cyclosporine ; chemistry ; pharmacology ; Daptomycin ; chemical synthesis ; chemistry ; pharmacology ; Depsipeptides ; chemical synthesis ; chemistry ; therapeutic use ; Gramicidin ; chemical synthesis ; chemistry ; pharmacology ; Humans ; Immunosuppression ; Immunosuppressive Agents ; chemical synthesis ; chemistry ; pharmacology ; Molecular Structure ; Neoplasms ; drug therapy ; Peptides, Cyclic ; chemical synthesis ; chemistry ; pharmacology ; therapeutic use ; Quantitative Structure-Activity Relationship ; Vancomycin ; chemical synthesis ; chemistry ; pharmacology

INTRODUCTIONVancomycin-resistant enterococci (VRE) have emerged as one of the major nosocomial antimicrobial-resistant pathogens globally. In this article, we describe the epidemiology of VRE in Singaporean public hospitals in the 5 years following the major local VRE outbreak in 2005.

MATERIALS AND METHODSA passive laboratory surveillance programme identified non-duplicate VRE isolates from 7 hospitals from 2006 to 2010. Descriptive statistics and time-series analysis was performed on all clinical VRE isolates for each individual hospital as well as for the combined dataset.

RESULTSThere were a total of 418 VRE isolates over 5 years, of which 102 isolates (24.4%) were from clinical cultures. Between 0.4% and 0.7% of all clinical enterococcal isolates were resistant to vancomycin. The overall incidence-density of VRE did not change over time in Singapore despite 2 separate outbreaks in tertiary hospitals in 2009 and 2010. Incidence-density of clinical VRE cases fell in 2 secondary hospitals, while another 2 hospitals experienced no significant VRE infections after 2008.

CONCLUSIONThe prevalence of VRE clinical isolates remains low in Singaporean public sector hospitals. However, the presence of at least 2 outbreaks in separate hospitals over the past 5 years indicates the need for continued vigilance in order to prevent any further increase in VRE prevalence locally.

Anti-Bacterial Agents ; pharmacology ; Cross Infection ; epidemiology ; Enterococcus ; drug effects ; isolation & purification ; Gram-Positive Bacterial Infections ; drug therapy ; Hospitals, Public ; Humans ; Population Surveillance ; Singapore ; epidemiology ; Vancomycin ; therapeutic use ; Vancomycin Resistance ; drug effects

OBJECTIVES: Gram-positive cocci is the main pathogen responsible for early infection after liver transplantation (LT), posing a huge threat to the prognosis of liver transplant recipients. This study aims to analyze the distribution and drug resistance of Gram-positive cocci, the risk factors for infections and efficacy of antibiotics within 2 months after LT, and to guide the prevention and treatment of these infections. METHODS: In this study, data of pathogenic bacteria distribution, drug resistance and therapeutic efficacy were collected from 39 Gram-positive cocci infections among 256 patients who received liver transplantation from donation after citizens' death in the Third Xiangya Hospital of Central South University from January 2019 to July 2022, and risk factors for Gram-positive cocci infection were analyzed. RESULTS: Enterococcus faecium was the dominant pathogenic bacteria (33/51, 64.7%), followed by Enterococcus faecalis (11/51, 21.6%). The most common sites of infection were abdominal cavity/biliary tract (13/256, 5.1%) and urinary tract (10/256, 3.9%). Fifty (98%) of the 51 Gram-positive cocci infections occurred within 1 month after LT. The most sensitive drugs to Gram-positive cocci were teicoplanin, tigecycline, linezolid and vancomycin. Vancomycin was not used in all patients, considering its nephrotoxicity. Vancomycin was not administered to all patients in view of its nephrotoxicity.There was no significant difference between the efficacy of daptomycin and teicoplanin in the prevention of cocci infection (P>0.05). Univariate analysis indicated that preoperative Model for End-Stage Liver Disease (MELD) score >25 (P=0.005), intraoperative red blood cell infusion ≥12 U (P=0.013) and exposure to more than 2 intravenous antibiotics post-LT (P=0.003) were related to Gram-positive cocci infections. Multivariate logistic regression analysis revealed that preoperative MELD score >25 (OR=2.378, 95% CI 1.124 to 5.032, P=0.024) and intraoperative red blood cell transfusion ≥ 12 U (OR=2.757, 95% CI 1.227 to 6.195, P=0.014) were independent risk factors for Gram-positive cocci infections after LT. Postoperative Gram-positive cocci infections were reduced in LT recipients exposing to more than two intravenous antibiotics post-LT (OR=0.269, 95% CI 0.121 to 0.598, P=0.001). CONCLUSIONS Gram-positive cocci infections occurring early after liver transplantation were dominated by Enterococcus faecalis infections at the abdominal/biliary tract and urinary tract. Teicoplanin, tigecycline and linezolid were anti-cocci sensitive drugs. Daptomycin and teicoplanin were equally effective in preventing cocci infections due to Gram-positive cocci. Patients with high preoperative MELD score and massive intraoperative red blood cell transfusion were more likely to suffer Gram-positive cocci infection after surgery. Postoperative Gram-positive cocci infections were reduced in recipients exposing to more than two intravenous antibiotics post-LT.
Humans ; Daptomycin/therapeutic use* ; Linezolid/therapeutic use* ; Teicoplanin/therapeutic use* ; Gram-Positive Cocci ; Liver Transplantation/adverse effects* ; Tigecycline/therapeutic use* ; End Stage Liver Disease/drug therapy* ; Gram-Positive Bacterial Infections/microbiology* ; Severity of Illness Index ; Anti-Bacterial Agents/pharmacology* ; Vancomycin/therapeutic use* ; Microbial Sensitivity Tests

The aim of this study was to determine the risk factors for nosocomial infections of imipenem-resistant Pseudomonas aeruginosa (IRPA). A prospective case-control study was performed at a tertiary care hospital in Ankara from January to December 2004. The patients with nosocomial P. aeruginosa infection were included in the study. The features of the patients with IRPA infections were compared to those with imipenem-sensitive P. aeruginosa (ISPA) infections. Only the first isolation of P. aeruginosa was considered. Nosocomial infections were defined according to Center for Disease Control (CDC) criteria. IRPA was isolated from 75 (44.1%) patients, and ISPA was isolated from 95 (55.9%) patients during the study period. IRPA were most frequently isolated from endotracheal aspirate (19%) cultures (p= 0.048), whereas ISPA were most frequently isolated from urine (28%) cultures (p= 0.023). In multivariate analysis, a longer duration of hospital stay until P. aeruginosa isolation (odds ratio [OR], 1.027; 95% confidence interval [CI], 1.002-1.054, p=0.034), arterial catheter administration (OR, 2.508; 95% CI, 1.062-5.920, p=0.036), vancomycin (OR, 2.882; 95% CI, 1.130-7.349, p=0.027), piperacillin-tazobactam (OR, 6.425; 95% CI, 2.187-18.875, p=0.001), and imipenem (OR, 3.580; 95% CI, 1.252- 10.245, p=0.017) treatment within the 14 days before isolation of IRPA were independently associated with imipenem resistance. It was concluded that treatment with imipenem, vancomycin and piperacillin-tazobactam were major risk factors for IRPA infections in hospitalized patients. The nosocomial occurrence of IRPA was also strongly related to the duration of hospital stay, arterial catheter administration.
Adult ; Aged ; Anti-Bacterial Agents/*pharmacology/therapeutic use ; Case-Control Studies ; Cross Infection/drug therapy/epidemiology/*microbiology ; Drug Resistance, Multiple, Bacterial ; Female ; Humans ; Imipenem/*pharmacology/therapeutic use ; Length of Stay ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Multivariate Analysis ; Penicillanic Acid/analogs & derivatives/pharmacology/therapeutic use ; Piperacillin/pharmacology/therapeutic use ; Prospective Studies ; Pseudomonas Infections/drug therapy/epidemiology/*microbiology ; Pseudomonas aeruginosa/drug effects/*isolation & purification ; Risk Factors ; Vancomycin/pharmacology/therapeutic use

Although Corynebacterium amycolatum can cause opportunistic infections, it is commonly considered as contaminant. In this report, we present a case of bacteremia caused by C. amycolatum with a novel mutation in the gyrA gene that confers high-level quinolone resistance to the organism.
Aged, 80 and over ; Anti-Bacterial Agents/*pharmacology ; Bacteremia/*microbiology ; Corynebacterium/drug effects/*genetics/isolation & purification ; Corynebacterium Infections/*diagnosis/drug therapy ; DNA Gyrase/*genetics ; Drug Resistance, Bacterial/genetics ; Fluoroquinolones/*pharmacology ; Humans ; Male ; Microbial Sensitivity Tests ; Mutation ; Vancomycin/therapeutic use

BACKGROUND: We estimated the prevalence and clinical impact of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). The concordance between macromethod and glycopeptide resistance detection (GRD) E tests was determined. In addition, predictors of clinical outcomes in hospitalized patients with S. aureus bacteremia (SAB) or pneumonia (SAP) were evaluated. METHODS: We obtained 229 consecutive S. aureus isolates from all hospitalized patients at two university hospitals located in Busan and Yangsan, Korea. Standard, macromethod, and GRD E tests were performed. Additionally, we reviewed the medical records of all patients. Among the 229 patients, predictors of clinical outcomes were analyzed for 107 patients with SAB and 39 with SAP. RESULTS: Among the 229 isolates, 34.5% of S. aureus isolates and 50.7% of methicillin-resistant S. aureus isolates exhibited the hVISA phenotype based on the macromethod E test. hVISA was nearly associated with treatment failure in patients with SAB (P=0.054) and was significantly associated with treatment failure in patients with SAP (P=0.014). However, hVISA was not associated with 30-day mortality in patients with SAB or SAP. The concordance between the macromethod and GRD E tests was 84.2%. CONCLUSIONS: hVISA is quite common in the southeastern part of Korea. hVISA is associated with treatment failure in patients with SAP.
Aged ; Anti-Bacterial Agents/*pharmacology/therapeutic use ; Bacteremia/drug therapy/epidemiology/microbiology ; Drug Resistance, Bacterial/*drug effects ; Female ; Hospital Mortality ; Hospitalization ; Humans ; Male ; Methicillin-Resistant Staphylococcus aureus/drug effects/isolation & purification ; Microbial Sensitivity Tests ; Middle Aged ; Phenotype ; Pneumonia/drug therapy/epidemiology/microbiology ; Prevalence ; Republic of Korea/epidemiology ; Staphylococcus aureus/*drug effects/isolation & purification ; Teicoplanin/pharmacology ; Vancomycin/pharmacology/*therapeutic use

INTRODUCTIONUntil recently, vancomycin-resistant enterococcus (VRE) infection or colonisation was a rare occurrence in Singapore. The first major VRE outbreak involving a 1500-bed tertiary care institution in March 2005 presented major challenges in infection control and came at high costs. This study evaluates the predictors of VRE carriage based on patients' clinical and demographic profiles.

MATERIALS AND METHODSStudy patients were selected from the hospital inpatient census population during the VRE outbreak (aged 16 years or more). Clinical information from 84 cases and 377 controls were analysed.

RESULTSSignificant predictors of VRE carriage included: age>65 years Odds ratio (OR), 1.98; 95% CI (confidence interval), 1.14 to 3.43); female gender (OR, 2.15; 95% CI, 1.27 to 3.65); history of diabetes mellitus (OR, 1.94; 95% CI, 1.14 to 3.30), and staying in a crowded communal ward (OR, 2.75; 95% CI, 1.60 to 4.74). Each additional day of recent hospital stay also posed increased risk (OR, 1.03; 95% CI, 1.01 to 1.04).

CONCLUSIONElderly diabetic females with prolonged hospitalisation in crowded communal wards formed the profile that significantly predicted VRE carriage in this major hospital-wide outbreak of VRE in Singapore. It is imperative that active VRE surveillance and appropriate infection control measures be maintained in these wards to prevent future VRE outbreaks.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Cross Infection ; drug therapy ; epidemiology ; microbiology ; Disease Outbreaks ; Enterococcus ; drug effects ; Enterococcus faecalis ; isolation & purification ; Enterococcus faecium ; isolation & purification ; Female ; Humans ; Infection Control ; Male ; Medical Audit ; Middle Aged ; Risk Factors ; Singapore ; epidemiology ; Streptococcal Infections ; drug therapy ; epidemiology ; Vancomycin ; pharmacology ; therapeutic use ; Vancomycin Resistance

Coagulase-negative staphylococci (CoNS) are reported to be the leading cause of nosocomial bloodstream infections. Staphylococcus pettenkoferi is a novel member of CoNS that was first isolated from the human blood and bursitis wound in 2002. We have reported cases of 6 S. pettenkoferi strains isolated from blood specimens, including one pathogen and 5 contaminants and catheter colonizers. Brucker Biotyper (Brucker Daltonics, Bremen, Germany) and molecular typing with 16S rRNA gene sequencing confirmed the 6 isolates as S. pettenkoferi. The conventional phenotypic identification of these isolates is not reliable owing to their inconsistent biochemical characteristics. Five of the 6 isolates were found to be resistant to oxacillin, and all isolates showed susceptibility to vancomycin and linezolid. For accurate identification of this novel species, advanced methods by using Brucker Biotyper or molecular methods such as 16S rRNA gene sequencing are required.
Aged ; Aged, 80 and over ; Anti-Bacterial Agents/pharmacology/therapeutic use ; DNA, Bacterial/chemistry/metabolism ; Drug Resistance, Bacterial/drug effects ; Female ; Humans ; Linezolid/pharmacology ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Oxacillin/pharmacology ; Phenotype ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Sequence Analysis, DNA ; Staphylococcal Infections/drug therapy/*microbiology/pathology ; Staphylococcus/drug effects/*genetics/isolation & purification ; Vancomycin/pharmacology