INTRODUCTIONPolymyxins have become the drug of choice for treatment of multidrug-resistant gram-negative bacilli infections in Singapore, simply because these pathogens are only susceptible to either aminoglycosides and polymyxins, or polymyxins only. Furthermore, there is no new antibiotic in the pipeline that targets these difficult-to-treat infections.

MATERIALS AND METHODSAll published literatures (up to end of February 2008) regarding polymyxins are included for review.

RESULTSThis review serves to give a summary of polymyxins from the current available literature, highlighting relevant clinical studies and information that help to guide informed prescription of polymyxins, should the need arise.

CONCLUSIONSHowever, there are substantial information gaps that needed to be filled urgently, to preserve the clinical utility of this very last line of antibiotic.

Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Drug Resistance, Multiple, Bacterial ; Gram-Negative Bacteria ; drug effects ; Gram-Negative Bacterial Infections ; drug therapy ; microbiology ; Humans ; Microbial Sensitivity Tests ; Polymyxins ; pharmacology ; therapeutic use ; Singapore

INTRODUCTIONStenotrophomonas maltophilia is an emerging pathogen in nosocomial infections that may result in high mortality. S. maltophilia often present as part of a polymicrobial culture and it is not well established when treatment is indicated. We aimed to identify predictors of mortality in patients with positive cultures of S. maltophilia.

MATERIALS AND METHODSA retrospective cohort study in a tertiary care medical centre was performed in 150 adult patients with positive cultures of S. maltophilia. Patients' demographics, underlying diseases, severity of illness, length of hospitalisation, prior antibiotic exposure, number/types of indwelling catheters, culture sites, and appropriateness of empiric therapy were collected. Logistic regression was used to determine the independent risk factor(s) for infection-attributed mortality.

RESULTSNinety-nine males and 51 females were studied. The mean (SD) age and APACHE II score of the patients were 61.9 (16.0) and 14.0 (6.1), respectively. The respiratory tract was the most frequent site (55.3%) where S. maltophilia was isolated. Infection-attributed mortality was observed in 22 of the 150 patients (14.7 %). Admission to ICU [Odds ratio (OR), 3.767; 95% confidence interval (CI), 1.277-11.116, P = 0.016], and delayed effective treatment (OR, 18.684; 95% CI, 4.050-86.188; P <0.001) were identified as independent risk factors for mortality.

CONCLUSIONSPredictors of mortality in patients with positive cultures of S. maltophilia were identified, which may guide clinicians in patient assessment and devising therapeutic decisions. Further studies are needed to validate our results.

APACHE ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anti-Infective Agents ; therapeutic use ; Cohort Studies ; Confidence Intervals ; Cross Infection ; drug therapy ; mortality ; Female ; Gram-Negative Bacterial Infections ; drug therapy ; mortality ; Humans ; Intensive Care Units ; Logistic Models ; Male ; Middle Aged ; Odds Ratio ; Predictive Value of Tests ; Respiratory System ; microbiology ; Retrospective Studies ; Risk Factors ; Singapore ; epidemiology ; Stenotrophomonas maltophilia ; drug effects ; isolation & purification ; Treatment Outcome ; Trimethoprim, Sulfamethoxazole Drug Combination ; therapeutic use

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