We describe the impact of enhanced infection control interventions on controlling the spread of vancomycin-resistant enterococci (VRE) in our hematology-oncology unit. Between April and September 1998, 13 patients on this unit were identified as having VRE. In addition to contact precautions, other measures that were needed to control the outbreak included closure of the unit to new admissions, creation of a cohort of VRE-positive patients and staff, and thorough cleaning of patients' rooms with 0.5% sodium hypochlorite.
The activities of tigecycline and comparative agents on staphylococci and enterococci isolated from patients at general hospital wards (GHWs) and intensive care units (ICUs) at 3 university hospitals in Sweden were investigated. Oxacillin disc diffusion and minimal inhibitory concentration with E-test were used. The presence of mecA, vanA or vanB genes was determined with PCR. Statistically significant higher incidence of clindamycin, fusidic acid, rifampicin and multidrug-resistant CoNS was found at ICUs compared to GHWs. Resistance rates were low among S. aureus. Tigecycline, linezolid and vancomycin were the only agents with high activity against methicillin-resistant S. aureus and multidrug-resistant CoNS. Resistance rates were low among E. faecalis, except for high-level gentamicin-resistant (HLGR) E. faecalis. E. faecium showed high resistance rates to ampicillin, piperacillin/tazobactam and imipenem. The HLGR rates among E. faecium were lower than the rates for E. faecalis. Tigecycline and linezolid were the only drugs with high activity against all enterococci including vancomycin-resistant enterococci. No statistically significant differences in susceptibility rates were found between the ward levels for S. aureus and enterococcal isolates and no statistically significant differences were found between the hospitals.
Antibiotic resistance has increased rapidly during the last decade, creating a serious threat to the treatment of infectious diseases. Canada is no exception to this worldwide phenomenon. Data from the Canadian Nosocomial Infection Surveillance Program have revealed that the incidence of methicillin-resistant Staphylococcus aureus, as a proportion of S. aureus isolates, increased from 1% in 1995 to 8% by the end of 2000, and vancomycin-resistant enterococcus has been documented in all 10 provinces since the first reported outbreak in 1995. The prevalence of nonsusceptible Streptococcus pneumoniae in Canada in 2000 was found to be 12%. Human antimicrobial prescriptions, adjusted for differences in the population, declined 11% based on the total number of prescriptions dispensed between 1995 and 2000. There was also a 21% decrease in beta-lactam prescriptions during this same period. These data suggest that systematic efforts to reduce unnecessary prescribing of antimicrobials to outpatients in Canada, beginning after a national consensus conference in 1997, may be having an impact. There is, however, still a need for continued concerted efforts on a national, provincial and regional level to quell the rising tide of antibiotic resistance.
Cites: N Engl J Med. 1996 Nov 7;335(19):1445-538875923
The CANWARD study (Canadian Ward Surveillance Study) assessed the antimicrobial susceptibility of a variety of available agents against 15 644 pathogens isolated from patients in Canadian hospitals between 2007 and 2009. The most active (based on MIC data) agents against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci were daptomycin, linezolid, tigecycline, and vancomycin (MRSA only) with MIC(90)'s (Âµg/mL) of 0.25 and 2, 2 and 2, 0.5 and 0.12, and 1, respectively. The most active agents against extended-spectrum Ã?-lactamase-producing Escherichia coli were colistin (polymyxin E), doripenem, ertapenem, meropenem, and tigecycline with MIC(90)'s (Âµg/mL) of 1, = 0.12, 0.25, = 0.12, and 1, respectively. The most active agents against Pseudomonas aeruginosa were amikacin, cefepime, ceftazidime, colistin, doripenem, meropenem, and piperacillin-tazobactam with MIC(90)'s (Âµg/mL) of 32, 16, 32, 2, 4, 8, and 64, respectively. Overall, the most active agents versus Gram-positive cocci from Canadian hospitals were vancomycin, linezolid, daptomycin, and tigecycline and versus Gram-negative bacilli were amikacin, cefepime, doripenem, ertapenem (excluding Pseudomonas aeruginosa), meropenem, piperacillin-tazobactam, and tigecycline (excluding Pseudomonas aeruginosa).
A case-control study was conducted to determine the modifiable risk factors associated with vancomycin-resistant Enterococcus (VRE) colonization during a hospital outbreak. Cephalosporin use was identified as the only independent risk factor (odds ratio, 13.8; 95% confidence interval, 2.5-76.3; P = .01). Nursing work-load intensity was not associated with VRE colonization in this study.
Clustering of polyclonal VanB-type vancomycin-resistant Enterococcus faecium in a low-endemic area was associated with CC17-genogroup strains harbouring transferable vanB2-Tn5382 and pRUM-like repA containing plasmids with axe-txe plasmid addiction systems.
VanB-type vancomycin-resistant Enterococcus faecium isolates (n = 17) from 15 patients at the Örebro University hospital in Sweden during a span of 18 months was characterized. All patients had underlying disorders and received broad-spectrum antimicrobial therapy. Pulsed-field gel electrophoresis (PFGE) grouped 14 isolates in three PFGE types and three isolates in unique PFGE patterns. All isolates had multi-locus sequence types [ST17 (n = 5); ST18 (n = 3); ST125 (n = 7); ST262 (n = 1); ST460 (n = 1)] belonging to the successful hospital-adapted clonal complex 17 (CC17), harboured CC17-associated virulence genes, were vanB2-positive and expressed diverse vancomycin minimum inhibitory concentration (MICs; 8 to > 256 mg/L). Isolate 1 had a unique PFGE type and a chromosomal transferable vanB2-Tn5382 element. Interestingly, the other five PFGE types had Tn5382 located on plasmids containing pRUM-like repA and a plasmid addiction system (axe-txe) shown by co-hybridization analysis of PFGE-separated S1-nuclease digested total DNA. The resistance plasmids were mainly of 120-kb and supported intraspecies vanB transfer. Two strains were isolated from patient 6 and we observed a possible transfer of the vanB2-resistance genes from PFGE type III ST460 to a more successful PFGE type I ST125. This latter PFGE type I ST125 became the predominant type afterwards. Our observations support the notion that vanB-type vancomycin-resistant Enterococcus faecium can persist in a low-endemic area through successful clones and plasmids with stability functions in hospital patients with known risk factors.
This study assessed the demographics, antimicrobial susceptibility, and molecular epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and health care-associated MRSA (HA-MRSA) in Canadian hospitals between 2007 and 2009. Among 3589 S. aureus, 889 (24.8%) were MRSA; 224 (25.2%) were CA-MRSA genotypes and 644 (72.4%) were HA-MRSA genotypes. The prevalence of CA-MRSA genotypes increased from 19.5% in 2007 to 31.9% in 2009 (P
A comparison of infection control program resources, activities, and antibiotic resistant organism rates in Canadian acute care hospitals in 1999 and 2005: pre- and post-severe acute respiratory syndrome.
The Resources for Infection Control in Hospitals (RICH) project assessed infection control programs and rates of antibiotic-resistant organisms (AROs) in Canadian acute care hospitals in 1999. In the meantime, the severe acute respiratory syndrome (SARS) outbreak and the concern over pandemic influenza have stimulated considerable government and health care institutional efforts to improve infection control systems in Canada.
In 2006, a version of the RICH survey similar to the original RICH instrument was mailed to infection control programs in all Canadian acute care hospitals with 80 or more beds. We used chi(2), analysis of variance, and analysis of covariance analyses to test for differences between the 1999 and 2005 samples for infection control program components and ARO rates.
72.3% of Canadian acute care hospitals completed the RICH survey for 1999 and 60.1% for 2005. Hospital size was controlled for in analyses involving AROs and surveillance and control intensity levels. Methicillin-resistant Staphylococcus aureus (MRSA) rates increased from 1999 to 2005 (F = 9.4, P = .003). In 2005, the mean MRSA rate was 5.2 (standard deviation [SD], 6.1) per 1000 admissions, and, in 1999, it was 2.0 (SD, 2.9). Clostridium difficile-associated diarrhea rates trended up from 1999 to 2005 (F = 2.9, P = .09). In 2005, the mean Clostridium difficile-associated diarrhea rate was 4.7 (SD, 4.3), and, in 1999, it was 3.8 (SD, 4.3). The proportion of hospitals that reported having new nosocomial vancomycin-resistant Enterococcus (VRE) cases was greater in 2005 than in 1999 (chi(2) = 10.5, P = .001). In 1999, 34.5% (40/116) of hospitals reported having new nosocomial VRE cases, and, in 2005, 61.0% (64/105) reported new cases. Surveillance intensity index scores increased from a mean of 61.7 (SD, 18.5) in 1999 to 68.1 (SD, 15.4) in 2005 (F = 4.1, P = .04). Control intensity index scores trended upward slightly from a mean of 60.8 (SD, 14.6) in 1999 to 64.1 (SD, 12.2) in 2005 (F = 3.2, P = .07). Infection control professionals (ICP) full-time equivalents (FTEs) per 100 beds increased from a mean of 0.5 (SD, 0.2) in 1999 to 0.8 (SD, 0.3) in 2005 (F = 90.8, P
ReprintIn: Can J Infect Control. 2009 Summer;24(2):109-1519697536
We compared our current screening strategy for vancomycin-resistant Enterococcus (VRE) with a focused strategy that screens all stool samples sent for Clostridium difficile toxin assay but limits rectal swab screening to wards with new VRE cases detected via C. difficile samples. The proposed strategy detects 72.7% of new VRE cases, with substantial cost savings.