| 1. |
- Andersson, Helene, et al.
(författare)
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Prevalence of antibiotic-resistant bacteria in residents of nursing homes in a Swedish municipality : healthcare staff knowledge of and adherence to principles of basic infection prevention
- 2012
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Ingår i: Scandinavian journal of infectious diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 44:9, s. 641-649
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background: The aims of this study were to investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in residents living in Swedish nursing homes, and if carriage of resistant bacteria was related to antibiotic treatment, other risk factors, and/or staff's adherence to guidelines for infection control. Methods: Five hundred and sixty residents from 9 nursing homes on a total of 67 wards participated in the study and had microbiological cultures taken. Faecal samples were obtained from 495 residents (88.3%). ESBL-positive residents were followed for 2 y with repeated sampling. Two hundred and ninety-six staff members were interviewed and observed regarding familiarity with and adherence to infection control guidelines. Results: No resident was positive for MRSA or VRE. Fifteen of the residents were found to be ESBL-positive. Residents living on wards where ESBL-positive residents were identified had been treated more frequently with antibiotics (42%), compared to those on wards where no residents with ESBL were found (28%; p = 0.02). ESBL-positive Escherichia coli isolates from residents living in adjacent rooms were found to be closely genetically related when analysed by pulsed-field gel electrophoresis, indicating transmission between residents. Staff adherence to infection control guidelines sometimes revealed shortcomings, but no significant differences regarding compliance to the guidelines could be found. Conclusion: Carriage of resistant bacteria was uncommon and only ESBL-producing Enterobacteriaceae were identified in Swedish nursing homes. Usage of antibiotics was higher on wards where ESBL-positive residents were detected and there was an indication of transmission of ESBL between residents.
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| 2. |
- Iversen, Aina, et al.
(författare)
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Evidence for transmission between humans and the environment of a nosocomial strain of Enterococcus faecium.
- 2004
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Ingår i: Environ Microbiol. - : Wiley. - 1462-2912. ; 6:1, s. 55-9
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Tidskriftsartikel (refereegranskat)abstract
- An ampicillin- and ciprofloxacin-resistant Enterococcus faecium (ARE) strain, named FMSE1, with a characteristic biochemical phenotype, was in a recent study found to dominate among faecal ARE isolates from patients in several Swedish hospitals. In the present study, the prevalence of this strain among 9676 enterococcal isolates from healthy children, hospital sewage, urban sewage, surface water, slaughtered animals (broilers, pigs and cattle) and pig faeces and manure was investigated. Enterococcal isolates having the same biochemical phenotype as the FMSE1 were most common in samples of hospital sewage (50%), surface water (35%), treated sewage (28%) and untreated sewage (17%), but rare in samples from healthy children (0.8%) and animals (2%). PFGE typing of FMSE1-like isolates from hospital sewage indicated that they were closely related to the nosocomial FMSE1 strain. Thus, this study indicated a possible transmission route for nosocomial E. faecium from patients in hospitals to hospital sewage and urban sewage, and further via treatment plants to surface water and possibly back to humans. This proposed route of circulation of drug-resistant enterococci might be further amplified by antibiotic usage in human medicine. In contrast, such transmission from food animals seems to play a negligible role in Sweden.
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| 3. |
- Iversen, Aina
(författare)
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Population structure and antibiotic resistance of the genus enterococcus in humans, animals and the environment
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Enterococci belong to the normal intestinal flora of humans and animals. An increased prevalence of antibiotic resistant enterococci causing nosocomial infections has drawn attention to the epidemiology and emergence of antibiotic resistance in this genus. In the present thesis we have studied the enterococcal flora in samples from humans, animals, and the environment, in order to be able to follow the movement of bacteria between different ecological niches, as well as to determine the prevalence of antibiotic resistant enterococci in these samples. In a European study, 17,157 enterococcal isolates from 2,868 samples from humans, animals and the environment in Sweden, Denmark, the United Kingdom, and Spain were studied (study I-III). The diversities of enterococci in environmental samples were generally high. Samples from hospital sewage, urban sewage, and manure contained enterococcal populations that reflected those in faecal samples of hospitalised patients, healthy humans and animals. Thus, such samples could be used as pooled faecal samples and replace cumbersome samplings from many individuals. Vancomycin resistant enterococci (VRE, resistant to 20 mg/L vancomycin), were identified in 8.2% of all samples and most frequently and at similar levels in untreated urban sewage in Sweden, Spain and the UK (in an average of 71% of the samples). In contrast, pig faeces and manure were more often VRE-positive in Spain than in Sweden (30% vs. 1%), most probably reflecting the former use of the vancomycin analogue avoparcin as a feed additive. Most VRE were E. faecium carrying vanA both among humans and animals. Typing of VRE showed a high degree of polyclonality and no evidence were found for transmission of VRE strains between humans and animals. The high prevalence of VRE in Swedish sewage samples (19-60% in 118 samples) was unexpected. Typing of 35 isolates revealed a high diversity (Di 0.97). Four of five VRE from hospital sewage were E. faecium with vanB, which is the most common type in infections and among hospitalised patients in Sweden. However, the origin of VRE from urban sewage remains unclear. A majority of VRE from urban sewage were E. faecium with vanA (17 of 29), but a larger proportion than found in the other countries was E. faecalis with vanA (11of 29). Either these VRE represent a higher carriage rate among healthy individuals in the community than earlier reported or perhaps they harbour in the sewage system. An ampicillin and ciprofloxacin resistant E. faecium (ARE) strain, named FMSE1, was in a previous study found to dominate among faecal ARE isolates from patients in several Swedish hospitals. In study IV, the prevalence of the same PhP-type as the FMSE1 PhP-type, was searched for among typing data from 9676 isolates from Sweden and Denmark. FMSE1 was most common in samples of hospital sewage (50%), surface water (35%), treated sewage (28%), and untreated sewage (17%), but were rare in samples from healthy children (0.8%) and animals (2%). PFGE typing of FMSE1-like isolates from hospital sewage indicated that they were closely related to the nosocomial FMSE1 strain. According to study I-III the enterococcal flora in sewage and hospital sewage resembled that of the flora in individual faecal samples. This fact led to an idea for a new concept for monitoring antibiotic resistance in the community and in hospitals, based on samplings of sewage water. In study V and VI the feasibility of this concept was evaluated. Up to 24 enterococcal isolates from each sample of hospital sewage (N=9), sewage treatment plants (N=14), and sewage from an anthroposophic village, were screened for resistance, using breakpoint concentrations of antibiotics in microplates. The resistance rates found for ampicillin, ciprofloxacin and erythromycin were markedly higher in hospital sewage (30, 35 and 30%) than in community sewage (4, 6 and 15%l), whereas tetracycline resistance was found at the same level in all sewage types (28%). Differences in resistance rates for enterococci isolated from different types of sewage samples were obvious and easy to monitor using this method.
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| 4. |
- Titelman, Emilia, et al.
(författare)
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Antimicrobial susceptibility to parenteral and oral agents in a largely polyclonal collection of CTX-M-14 and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae
- 2011
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 119:12, s. 853-863
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Tidskriftsartikel (refereegranskat)abstract
- Activity of oral and parenteral antimicrobials against consecutively isolated extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n = 149) and Klebsiella pneumoniae (n = 20) was determined, and susceptibility test methods were compared for parenteral beta-lactams. Polymerase chain reaction (PCR) targeting bla(CTX-M), bla(SHV) and bla(TEM), and DNA sequencing and epidemiological typing with pulsed-field gel electrophoresis were performed. PCR targeting pabB was screened for E. coli O25b-ST131. Minimum inhibitory concentrations (MICs) were determined using Etest and broth microdilution. Disc diffusion was performed according to European Committee on Antimicrobial Susceptibility Testing (EUCAST). Dominating genotypes were bla(CTX-M-15) (75%) and bla(CTX-M-14) (23%). Four E. coli clusters (7-18 isolates) were found. Forty-two per cent of E. coli belonged to O25b-ST131. Ciprofloxacin resistance was 72%, trimethoprim resistance was 70%. Among E. coli, resistance to mecillinam (13%), nitrofurantoin (7%) and fosfomycin (3%) was low, although resistance was high in K. pneumoniae (25%, 60%, 85%). Susceptibility to ertapenem was 99%, piperacillin-tazobactam 91%, tigecycline 96% and temocillin 76%. Susceptibility rates obtained with broth microdilution and Etest were in agreement for cefotaxime (2 vs 1%) and ceftazidime (9 vs 11%), but not for piperacillin-tazobactam (59 vs 91%). With disc diffusion major errors occurred with piperacillin-tazobactam (18/169). Several therapeutic alternatives exist for ESBL-producing E. coli, but few exist for K. pneumoniae. Disc diffusion and Etest can accurately predict susceptibility to cefotaxime and ceftazidime, but not to piperacillin-tazobactam with the present breakpoints.
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| 5. |
- Wong, Alicia Y. W., et al.
(författare)
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Evaluation of Four Lateral Flow Assays for the Detection of Legionella Urinary Antigen
- 2021
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Ingår i: Microorganisms. - : MDPI. - 2076-2607. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Urinary antigen tests (UATs) are often used to diagnose Legionnaires' disease as they are rapid and easy to perform on readily obtainable urine samples without the need for specialized skills compared to conventional methods. Recently developed automated readers for UATs may provide objective results interpretation, especially in cases of weak result bands. Using 53 defined patient urine samples, we evaluated the performance of the BinaxNOW Legionella Antigen Card (Abbott), ImmuView S. pneumoniae and Legionella (SSI Diagnostica), STANDARD F Legionella Ag FIA (SD Biosensor), and Sofia Legionella FIA (Quidel) simultaneously with their respective automated readers. Automatic and visual interpretation of result bands were also compared for the immunochromatography-based BinaxNOW and ImmuView UATs. Overall sensitivity and specificity of Legionella UATs were 53.9-61.5% and 90.0-94.9%, respectively. All four UATs successfully detected all samples from L. pneumophila serogroup 1-positive patients, but most failed to detect samples for Legionella spp., or other serogroups. Automatic results interpretation of results was found to be mostly concordant with visual results reading. In conclusion, the performance of the four UATs were similar to each other in the detection of Legionella urinary antigen with no major difference between automated or visual results reading.
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