Enterococcus faecalis and E. faecium isolated from humans in the community (98 and 65 isolates), broilers (126 and 122), and pigs (102 and 88) during 1998 were tested for susceptibility to 12 different antimicrobial agents and for the presence of selected genes encoding resistance using PCR. Furthermore, the presence of vancomycin resistant enterococci was examined in 38 human stool samples using selective enrichment. Widespread resistance to chloramphenicol, macrolides, kanamycin, streptomycin, and tetracycline was found among isolates from all three sources. All E. faecium isolates from humans and pigs were susceptible to avilamycin, whereas 35% of isolates from broilers were resistant. All E. faecium isolates from humans were susceptible to vancomycin, whereas 10% and 17% of isolates from broilers and pigs, respectively, were resistant. A vancomycin resistant E. faecium isolate was found in one of the 38 human fecal samples examined using selective enrichment. All vancomycin resistant isolates contained the vanA gene, all chloramphenicol resistant isolates the cat(pIP501) gene, and all five gentamicin resistant isolates the aac6-aph2 gene. Sixty-one (85%) of 72 erythromycin resistant E. faecalis examined and 57 (90%) of 63 erythromycin resistant E. faecium isolates examined contained ermB. Forty (91%) of the kanamycin resistant E. faecalis and 18 (72%) of the kanamycin resistant E. faecium isolates contained aphA3. The tet(M) gene was found in 95% of the tetracycline resistant E. faecalis and E. faecium isolates of human and animal origin, examined. tet(K) was not observed, whereas tet(L) was detected in 17% of tetracycline resistant E. faecalis isolates and in 16% of the E. faecium isolates. tet(O) was not detected in any of the isolates from pigs, but was observed in 38% of E. faecalis isolates from broilers, in two E. faecalis isolates from humans and in three E. faecium isolates from broilers. tet(S) was not detected among isolates from animals, but was observed in 31% of E. faecalis and one E. faecium isolate from humans. This study showed a frequent occurrence of antimicrobial resistance and the presence of selected resistance genes in E. faecalis and E. faecium isolated from humans, broilers and pigs. Differences in the occurrence of resistance and tetracycline resistance genes were observed among isolates from the different sources. However, similar resistance patterns and resistance genes were detected frequently indicating that transmission of resistant enterococci or resistance genes takes place between humans, broilers, and pigs.
To describe the investigation and control of transmission of vancomycin-resistant enterococci (VRE) in a residential long-term-care (LTC) setting. OUTBREAK INVESTIGATION: A strain of vancomycin-resistant Enterococcus faecium not previously isolated in Ontario colonized five residents of a 254-bed LTC facility in Toronto. The index case was identified when VRE was isolated from a urine culture taken after admission to a local hospital. Screening of rectal swabs from all 235 residents identified four others who were colonized with the same strain of E faecium.
Colonized residents were cohorted. VRE precautions were established as follows: gown and gloves for resident contact, restriction of contact between colonized and noncolonized residents, no sharing of personal equipment, and daily double-cleaning of residents' rooms and wheelchairs.
Two colonized residents died of causes unrelated to VRE. Although bacitracin therapy (75,000 units four times a day x 14 days) failed to eradicate carriage in two of three surviving residents, both cleared their carriage within 7 weeks. Repeat rectal swabs from 224 residents (91%) 2 months after isolation precautions were discontinued and from 125 residents (51%) 9 months later identified no new cases. Total cost of investigation and control was $12,061 (Canadian).
VRE may be transmitted in LTC facilities, and colonized LTC residents could become important VRE reservoirs. Control of VRE transmission in LTC facilities can be achieved even with limited resources.
Isolate and characterize water enterococci from the South Nation River drainage basin, an area dominated by agriculture.
A total of 1558 enterococci were isolated from 204 water samples from the South Nation River obtained over a 3-year period. PCR was used to identify isolates to the species level and characterize them for carriage of 12 virulence determinants. Antibiotic resistance was evaluated phenotypically. Enterococcus faecalis (36·4%), Enterococcus faecium (9·3%) and Enterococcus durans (8·5%) were the major enterococci species isolated. Enterococci carrying more than two virulence determinants were more frequently detected in the summer (59·6%) than in other seasons (= 37·6%). Very few isolates (= 2·0%) were resistant to category I antibiotics ciprofloxacin and vancomycin.
Comparison of major water enterococci species with major faecal enterococci species obtained from various host groups (human, domesticated mammals and birds, wildlife) in this drainage basin suggest that water enterococci may have varied faecal origins. The low level of antibiotic resistance among enterococci suggests that dispersion of antibiotic resistance via waterborne enterococci in this watershed is not significant.
The data obtained in this study suggests that water enterococci in the SNR have a faecal origin and that their potential impact on public health regarding antibiotic resistance and virulence determinants is minimal.
Vancomycin-resistant Enterococcus faecium and faecalis (VRE) remains a major complication among critically ill patients. A 26-year-old patient with 65% total body surface area burns (TBSA) was infected with several E. faecium strains during his admission that were resistant to vancomycin. Because chloramphenicol was the standard treatment at this time, this drug was initiated until, the organism was identified as E. faecium and reported as susceptible to quinupristin-dalfopristin. Given these data, it was then decided to discontinue the chloramphenicol therapy. Quinupristin-dalfopristin therapy resulted in initial reduction of fever and white blood cell counts that continued over the next 5 days. However, on day 7 of quinupristin-dalfopristin therapy, a return of fever and elevation of the white blood cell count was noted and a repeated E. faecium blood culture demonstrated sudden resistance to quinupristin-dalfopristin (Bauer-Kirby zone size
A vancomycin-resistant Enterococcus faecium isolate from the urine of a liver transplant patient in Stockholm was found to contain a vanD gene. The sequence of the vanD PCR product shared 100% identity with the vanD5 allele. The isolate was resistant to a relatively high level of vancomycin (128 mg/L) and a low level of teicoplanin (4 mg/L). This is the first VanD-type vancomycin-resistant E. faecium isolate reported in Sweden. The emergence of this strain reinforces the necessity of infection control efforts to interrupt the spread of these organisms.
A 5-year nationwide prospective study in Sweden during 1995-1999 identified 881 definite episodes of infective endocarditis. Definite enterococcal endocarditis was diagnosed in 93 episodes (11%), the largest series of enterococcal endocarditis so far presented. Mortality during treatment was 16%, the relapse rate was 3%, and clinical cure was achieved in the remaining 81% of the episodes. Clinical cure was achieved with a median duration of cell wall-active antimicrobial therapy of 42 days combined with an aminoglycoside (median treatment time, 15 days). International guidelines generally recommend a 4-6-week combined synergistic treatment course with a cell wall-active antibiotic and an aminoglycoside. Treatment regimens in Sweden often include a shortened aminoglycoside treatment course in order to minimize adverse effects in older patients. Fatal outcome seemed not to be due to the shortened aminoglycoside therapy course. In many enterococcal endocarditis episodes, duration of aminoglycoside therapy could probably be shortened to 2-3 weeks.
Enterococcus has become a more frequent cause of serious infections over the last 10-15 years. The infections are primarily nosocomial, owing to compromised immunity in the patients and excessive use of antibiotics in the hospitals. The rise is marked in the USA, where the enterococci furthermore tend to become multiresistant. Abroad, many enterococci have developed resistance to all available antibiotics, and their spread is now controllable only by strict hygienic precautions. No increase in enterococcal infections has been noted in Denmark, and very few clinical isolates of vancomycin-resistant enterococci have been found. Because of the worldwide relevance, we present a review of enterococcal infections with the focus on endocarditis and bacteraemia. However, we would emphasise that the classic combination of a penicillin and an aminoglycoside still provides adequate treatment of enterococcal infections in Denmark.
In recent years enterococci, and Enterococcus faecium in particular, have emerged as important nosocomial pathogens. Of major concern is the increasing antimicrobial resistance to traditionally used agents such as ampicillin, gentamicin and vancomycin. We present a patient with prosthetic heart valves colonized with vancomycin-resistant E. faecium. This is the first reported isolation of vancomycin-resistant E. faecium in Sweden.
To screen for the globally spread cluster of Enterococcus faecium, clonal complex 17 (CC17) and characterize the genetic profile of Swedish clinical Ent. faecium isolates.
A total of 203 consecutive isolates collected from 2004 to 2007 from patients with bacteraemia in Sweden. All isolates were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) and 20 isolates representing different MLVA types (MT) were chosen for multilocus sequence typing (MLST). Minimal inhibitory concentrations against clinically relevant antibiotics were determined with agar dilution. Presence of the virulence genes esp and hyl was investigated using PCR.
A total of 65% (n = 109) of all isolates belonged to MT-1, and the second most common MLVA type was MT-159 (13%, n = 21). MLST analysis confirmed the presence of CC17 during the entire study period. The number of isolates resistant to gentamicin and vancomycin, as well as the presence of hyl, increased significantly during the investigation period.
The present study demonstrates that nosocomial infections caused by Ent. faecium CC17 are commonly occurring in Sweden.
This is the first report of CC17 Ent. faecium in Sweden. The increase of antibiotic resistance and virulence indicates that these strains are further adapting to the hospital environment.
Six high-level evernimicin-resistant Enterococcus faecium isolates were identified among 304 avilamycin-resistant E. faecium isolates from animals and 404 stool samples from humans with diarrhea. All four animal isolates, and one of the human isolates, were able to transfer resistance to a susceptible E. faecium strain. The resulting transconjugants all tested positive for the presence of emtA, a gene encoding a methyltransferase previously linked with high-level evernimicin resistance. The four transconjugants derived from animal isolates all carried the same plasmid, while a differently sized plasmid was found in the isolate from humans. This study demonstrated a low incidence of high-level evernimicin resistance mediated by the emtA gene in different E. faecium isolates of animal and human origin.