| 1. |
- Balkhed Östholm, Åse, 1972-, et al.
(författare)
-
Duration of travel-associated faecal colonisation with ESBL-producing Enterobacteriaceae - A one year follow-up study
- 2018
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 13:10
-
Tidskriftsartikel (refereegranskat)abstract
- In a previous study, we found that 30% of individuals travelling outside Scandinavia acquired extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) in their faecal flora. The aim of this study was to determine the duration of travel-associated faecal colonisation with ESBL-PE, to assess risk factors for prolonged colonisation and to detect changes in antibiotic susceptibility during prolonged colonisation.
|
|
| 2. |
- Berglund, Björn, et al.
(författare)
-
Characterization of extended-spectrum -lactamase-producing Escherichia coli harboring mcr-1 and toxin genes from human fecal samples from China
- 2018
-
Ingår i: Future Microbiology. - : FUTURE MEDICINE LTD. - 1746-0913 .- 1746-0921. ; 13:15, s. 1647-1656
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To characterize extended-spectrum -lactamase-producing Escherichia coli harboring the colistin resistance gene mcr-1 from human fecal samples collected in 2012 in a rural area of Shandong province, PR China. Materials amp; methods: Whole-genome sequencing and antimicrobial susceptibility testing was performed on 25 mcr-1-positive isolates to determine carriage of antibiotic resistance and virulence genes, diversity and antibiotic resistance profiles. Results: The isolates were highly genetically diverse and carried a large variety of different antibiotic resistance genes. The multidrug-resistance rate was high (96%). Virulence genes associated with intestinal pathogenic E. coli were carried by 32% of the isolates. Conclusion: Further monitoring of the epidemiological situation is necessary to ensure a preparedness for potential emergence of novel, difficult-to-treat strains and awareness of available treatment options.
|
|
| 3. |
- Berglund, Björn, et al.
(författare)
-
Clonal spread of carbapenem-resistant Klebsiella pneumoniae among patients at admission and discharge at a Vietnamese neonatal intensive care unit
- 2021
-
Ingår i: Antimicrobial Resistance and Infection Control. - : BMC. - 2047-2994. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background The increasing prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is a growing problem globally, particularly in low- to middle-income countries (LMICs). Previous studies have shown high rates of CRE colonisation among patients at hospitals in LMICs, with increased risk of hospital-acquired infections. Methods We isolated carbapenem-resistant Klebsiella pneumoniae (CRKP) from faecal samples collected in 2017 from patients at admission and discharge at a Vietnamese neonatal intensive care unit (NICU). 126 CRKP were whole-genome sequenced. The phylogenetic relationship between the isolates and between clinical CRKP isolates collected in 2012-2018 at the same hospital were investigated. Results NDM-type carbapenemase-(61%) and KPC-2-encoding genes (41%) were the most common carbapenem resistance genes observed among the admission and discharge isolates. Most isolates (56%) belonged to three distinct clonal clusters of ST15, carrying bla(KPC-2), bla(NDM-1) and bla(NDM-4), respectively. Each cluster also comprised clinical isolates from blood collected at the study hospital. The most dominant ST15 clone was shown to be related to isolates collected from the same hospital as far back as in 2012. Conclusions Highly resistant CRKP were found colonising admission and discharge patients at a Vietnamese NICU, emphasising the importance of continued monitoring. Whole-genome sequencing revealed a population of CRKP consisting mostly of ST15 isolates in three clonally related clusters, each related to blood isolates collected from the same hospital. Furthermore, clinical isolates collected from previous years (dating back to 2012) were shown to likely be clonally descended from ST15 isolates in the largest cluster, suggesting a successful hospital strain which can colonise inpatients.
|
|
| 4. |
|
|
| 5. |
- Berglund, Björn, et al.
(författare)
-
Insertion sequence transpositions and point mutations in mgrB causing colistin resistance in a clinical strain of carbapenem-resistant Klebsiella pneumoniae from Vietnam
- 2018
-
Ingår i: International Journal of Antimicrobial Agents. - : ELSEVIER SCIENCE BV. - 0924-8579 .- 1872-7913. ; 51:5, s. 789-793
-
Tidskriftsartikel (refereegranskat)abstract
- Resistance among Klebsiella pneumoniae to the last-resort antibiotics carbapenems and colistin is increasing worldwide. In this study, whole-genome sequencing was used to determine the colistin resistance mechanisms in clinical isolates of carbapenem-and colistin-resistant K. pneumoniae from Vietnam. Alterations in the regulatory gene mgrB, via mutations and insertion sequence transpositions, were found in 30 of 31 isolates, emphasising the importance of this resistance mechanism in colistin-resistant K. pneumoniae. (c) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
|
|
| 6. |
- Bi, Zhenwang, et al.
(författare)
-
Prevalence of the mcr-1 colistin resistance gene in extended-spectrum beta-lactamase-producing Escherichia coli from human faecal samples collected in 2012 in rural villages in Shandong Province, China
- 2017
-
Ingår i: International Journal of Antimicrobial Agents. - : ELSEVIER SCIENCE BV. - 0924-8579 .- 1872-7913. ; 49:4, s. 493-497
-
Tidskriftsartikel (refereegranskat)abstract
- Since its initial discovery in China in 2015, the plasmid-mediated colistin resistance gene mcr-1 has been reported in Escherichia coli isolated from clinical samples, animals and meat worldwide. In this study, 706 extended-spectrum beta-lactamase (ESBL)-producing E. coli from 411 persons were detected in a collection of faecal samples from 1000 rural residents in three counties in Shandong Province, China. These isolates were screened for mcr-1 and phenotypic colistin resistance. The gene was found in 3.5% of the isolates (from 4.9% of persons) from all three counties. All isolates with phenotypic colistin resistance carried mcr-1. These data indicate that commensal carriage of ESBL-producing E. coli with mcr-1 among persons in rural China was already present in 2012 and that mcr-1 was the most important colistin resistance mechanism. Interventions are necessary to minimise further dissemination of mcr-1, which would limit the future usefulness of colistin as a last-resort antibiotic. (C) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
|
|
| 7. |
- Chabok, Abbas, et al.
(författare)
-
Prevalence of fecal carriage of antibiotic-resistant bacteria in patients with acute surgical abdominal infections
- 2010
-
Ingår i: SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. - : Informa Healthcare. - 0036-5521 .- 1502-7708. ; 45:10, s. 1203-1210
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. Antibiotic resistance is increasing worldwide. The aims of the current study were to determine the fecal carriage of antibiotic-resistant bacteria and antibiotic treatment in surgical patients admitted to hospital due to acute intra-abdominal infections. Materials and methods. Eight Swedish surgical units participated in this prospective multicenter investigation. Rectal swabs were obtained on admission to hospital. Cultures were performed on chromogenic agar and antibiotic susceptibility testing was performed using the disk diffusion method. Extended-spectrum beta-lactamase (ESBL)phenotype was confirmed by Etest. Results. Rectal samples were obtained and analyzed from 208 patients with intra-abdominal surgical infections. Surgery was performed in 134 patients (65%). Cephalosporins were the most frequently used empirical antibiotic therapy. The highest rates of resistance among Enterobacteriaceae were detected for ampicillin (54%), tetracycline (26%), cefuroxime (26%) and trimethoprim-sulfamethoxazole (20%). The prevalence of decreased susceptibility (I + R) for the other antibiotics tested was for ciprofloxacin 20%, piperacillin-tazobactam 17%, cefotaxime 14%, ertapenem 12%, gentamicin 3% and imipenem 0%. ESBL-producing Enterobacteriaceae were found in samples from 10 patients (5%). Three patients had five E. coli isolates producing AmpC enzymes. Conclusions. This study shows a high rate of resistance among Enterobacteriaceae against antibiotics which are commonly used in Sweden and should have implications for the future choice of antibiotics for surgical patients.
|
|
| 8. |
|
|
| 9. |
- Monstein, Hans-Jurg, et al.
(författare)
-
Molecular identification of blaCTX-M and blaOXY/K1 beta-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons.
- 2009
-
Ingår i: BMC Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 9:1, s. 7-
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Plasmid encoded blaCTX-M enzymes represent an important sub-group of class A beta-lactamases causing the ESBL phenotype which is increasingly found in Enterobacteriaceae including Klebsiella spp. Molecular typing of clinical ESBL-isolates has become more and more important for prevention of the dissemination of ESBL-producers among nosocomial environment. METHODS: Multiple displacement amplified DNA derived from 20 K. pneumoniae and 34 K. oxytoca clinical isolates with an ESBL-phenotype was used in a universal CTX-M PCR amplification assay. Identification and differentiation of blaCTX-M and blaOXY/K1 sequences was obtained by DNA sequencing of M13-sequence-tagged CTX-M PCR-amplicons using a M13-specific sequencing primer. RESULTS: Nine out of 20 K. pneumoniae clinical isolates had a blaCTX-M genotype. Interestingly, we found that the universal degenerated primers also amplified the chromosomally located K1-gene in all 34 K. oxytoca clinical isolates. Molecular identification and differentiation between blaCTX-M and bla OXY/K1-genes could only been achieved by sequencing of the PCR-amplicons. In silico analysis revealed that the universal degenerated CTX-M primer-pair used here might also amplify the chromosomally located blaOXY and K1-genes in Klebsiella spp. and K1-like genes in other Enterobacteriaceae. CONCLUSION: The PCR-based molecular typing method described here enables a rapid and reliable molecular identification of blaCTX-M, and blaOXY/K1-genes. The principles used in this study could also be applied to any situation in which antimicrobial resistance genes would need to be sequenced.
|
|
| 10. |
- Saeedi, Baharak, 1972-, et al.
(författare)
-
Phene Plate (PhP) biochemical fingerprinting : a screening method for epidemiological typing of enterococcal isolates?
- 2005
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 113:9, s. 603-612
-
Tidskriftsartikel (refereegranskat)abstract
- Pulsed-field gel electrophoresis (PFGE) is currently considered the gold standard for genotyping of enterococci. However, PFGE is both expensive and time-consuming. The purpose of this study was to investigate whether the PhP system can be used as a reliable clinical screening method for detection of genetically related isolates of enterococci. If so, it should be possible to minimize the number of isolates subjected to PFGE typing, which would save time and money. Ninety-nine clinical enterococcal isolates were analysed by PhP (similarity levels 0.90–0.975) and PFGE (similarity levels ≤3 and ≤6 bands) and all possible pairs of isolates were cross-classified as matched or mismatched. We found that the probability that a pair of isolates (A and B) belonging to the same type according to PhP also belong to the same cluster according to PFGE, i.e. p(APFGE=BPFGE • APhP=BPhP), and the probability that a pair of isolates of different types according to PhP also belong to different clusters according to PFGE, i.e. p(APFGE≠BPFGE • APhP≠BPhP), was relatively high for E. faecalis (0.86 and 0.96, respectively), but was lower for E. faecium (0.51 and 0.77, respectively). The concordance which shows the probability that PhP and PFGE agree on match or mismatch was 86%–93% for E. faecalis and 54%–66% for E. faecium, which indicates that the PhP method may be useful for epidemiological typing of E. faecalis in the current settings but not for E. faecium.
|
|
| 11. |
- Sun, Qiang, et al.
(författare)
-
Varying High Levels of Faecal Carriage of Extended-Spectrum Beta-Lactamase Producing Enterobacteriaceae in Rural Villages in Shandong, China: Implications for Global Health
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:11, s. e113121-
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance is considered a major threat to global health and is affected by many factors, of which antibiotic use is probably one of the more important. Other factors include hygiene, crowding and travel. The rapid resistance spread in Gram-negative bacteria, in particular extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E), is a global challenge, leading to increased mortality, morbidity and health systems costs worldwide. Knowledge about resistance in commensal flora is limited, including in China. Our aim was to establish the faecal carriage rates of ESBL-E and find its association with known and suspected risk factors in rural residents of all ages in three socio-economically different counties in the Shandong Province, China. Faecal samples and risk-factor information (questionnaire) were collected in 2012. ESBL-E carriage was screened using ChromID ESBL agar. Risk factors were analysed using standard statistical methods. Data from 1000 individuals from three counties and in total 18 villages showed a high and varying level of ESBL-E carriage. Overall, 42% were ESBL-E carriers. At county level the carriage rates were 49%, 45% and 31%, respectively, and when comparing individual villages (n = 18) the rate varied from 22% to 64%. The high level of ESBL-E carriage among rural residents in China is an indication of an exploding global challenge in the years to come as resistance spreads among bacteria and travels around the world with the movement of people and freight. A high carriage rate of ESBL-E increases the risk of infection with multi-resistant bacteria, and thus the need for usage of last resort antibiotics, such as carbapenems and colistin, in the treatment of common infections.
|
|
| 12. |
- Tärnberg, Maria, et al.
(författare)
-
Antimicrobial activity against a global collection of skin and skin structure pathogens: results from the Tigecycline Evaluation and Surveillance Trial (TEST), 2010-2014
- 2016
-
Ingår i: International Journal of Infectious Diseases. - : ELSEVIER SCI LTD. - 1201-9712 .- 1878-3511. ; 49, s. 141-148
-
Tidskriftsartikel (refereegranskat)abstract
- Background: As part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) we report antimicrobial resistance among Gram-positive and Gram-negative isolates collected globally from integumentary sources between 2010 and 2014. Methods: Minimum inhibitory concentrations and antimicrobial resistance were determined according to Clinical and Laboratory Standards Institute guidelines (US Food and Drug Administration breakpoints against tigecycline). The Cochran-Armitage trend test was used to identify statistically significant changes in resistance. Results: Global rates of methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Acinetobacter baumannii were 38% and 43%, respectively. No S. aureus isolates were resistant to linezolid or vancomycin; all isolates were susceptible to tigecycline. Two percent of Enterococcus faecalis and 28% of Enterococcus faecium were vancomycin-resistant. Extended-spectrum beta-lactamase (ESBL) producers accounted for 22% of Klebsiella pneumoniae and 16% of Escherichia coli. Resistance to minocycline among E. faecalis, E. faecium, K. pneumoniae, and E. coli decreased significantly (p amp;lt; 0.0001). There were significant increases (p amp;lt; 0.0001) in A. baumannii resistance to cefepime, ceftazidime, ceftriaxone, levofloxacin, meropenem, and piperacillin-tazobactam. Conclusions: Among isolates from integumentary sources, rates of MRSA and ESBL-producing Enterobacteriaceae are stabilizing. Carbapenems and tigecycline have retained their in vitro activity against Gram-positive and Gram-negative organisms. Few agents were active against A. baumannii; its increasing resistance is cause for concern. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.
|
|
| 13. |
- Tärnberg, Maria, 1976-
(författare)
-
Extended-spectrum beta-lactamase producing Enterobacteriaceae : aspects on detection, epidemiology and multi-drug resistance
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Beta-lactam antibiotics are the largest and most commonly used group of antimicrobial agents in Sweden as well as world-wide. They show very good tolerability and many of the drugs can be administrated orally. Bacteria expressing extended-spectrum beta-lactamases (ESBLs), enzymes hydrolysing penicillins and cephalosporins, may not respond to therapy using some of these antibiotics. The isolates are also often co-resistant to other antimicrobial agents, thus further limiting treatment options. Often parenterally administrated carbapenems is one of few safe treatment options left.In this thesis we have investigated the occurrence of ESBL producing Enterobacteriaceae in clinical isolates from Östergötland, Sweden, from 2002 until end of 2007 and the occurrence of multiresistance among ESBL producing E. coli. During these investigations we developed a simple method well suited for high-throughput analysis, for detection and sub typing of common ESBL genes.During the six year period, the prevalence of ESBL producing Enterobacteriaceae in Östergötland was very low, <1%, but increasing. The number of patients with ESBL producing E. coli increased significantly from 5 to 47 per year; K. pneumoniae remained between one and four per year. The genes found were dominated by CTX-M group 1 (67%), followed by group 9 (27%). There has been no reason to suspect an outbreak of nosocomial origin. The total consumption of antimicrobial agents was 10.7-12.1 DID per year in primary care; 1.14-1.30 DID per year in hospital care.Of eight oral agents tested, only three showed a generally high susceptibility; mecillinam (91%), nitrofurantoin (96%) and fosfomycin (99%). The corresponding figures for the fifteen tested parenterally administrated drugs were; amikacin (96%), tigecycline (99%), colistin (99%) and ≥99% susceptibility for the carbapenems.Sixty eight percent of the isolates were multiresistant. The most common multiresistance pattern was ESBL phenotype with decreased susceptibility to trimethoprim, trimethoprimsulfamethoxazole, ciprofloxacin, gentamicin and tobramycin. A significant difference in susceptibility between CTX-M groups, in favor of group 9 over group 1, was seen for many of the antibiotics tested; amoxicillin-clavulanic acid, aztreonam, cafepime, ceftibuten, ceftazidime, ciprofloxacin, gentamicin, piperacillin-tazobactam, temocillin, and tobramycin.In conclusion this thesis shows that the prevalence of ESBL producing Enterobacteriaceae in Östergötland was very low but increasing, and the total consumption of antimicrobial agents was stable. A majority of the isolates were multiresistant and a significant difference in susceptibility between CTX-M groups, in favor of group 9 over group 1, was seen for many of the antimicrobial agents tested.
|
|
| 14. |
- Tärnberg, Maria, et al.
(författare)
-
Identification of randomly selected colonies of Lactobacilli from normal vaginal fluid by pyrosequencing of the 16S rDNA Variable V1 and V3 Regions
- 2002
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 110:11, s. 802-810
-
Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to characterize lactobacilli in vaginal fluid from 23 adult healthy women by using high-throughput DNA sequencing for identification of a large number of randomly selected colonies appearing on Rogosa and blood agar. The typing method was based on broad-range PCR of 16S rRNA gene variable regions V1 and V3, pyrosequencing, and classification of the fragments by alignment with NCBI-catalogued sequences and type strain sequences. Four major groups of sequences were found among the 402 isolates clearly corresponding to Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners and Lactobacillus jensenii when compared to the sequences obtained for type strains. Our results indicate that pyrosequencing of 16S rRNA gene fragments as used here is a fast and reliable method well suited for identification to the species level, even within the Lactobacillus acidophilus complex.
|
|
| 15. |
- Tärnberg, Maria, et al.
(författare)
-
In vitro activity of beta-lactam antibiotics against CTX-M-producing Escherichia coli
- 2011
-
Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Science Business Media. - 0934-9723 .- 1435-4373. ; 30:8, s. 981-987
-
Tidskriftsartikel (refereegranskat)abstract
- Beta-lactam antibiotics have been discussed as options for the treatment of infections caused by multiresistant extended-spectrum beta-lactamase (ESBL)-producing bacteria if the minimum inhibitory concentration (MIC) is low. The objective of this study was to investigate the in vitro activity of different beta-lactam antibiotics against CTX-M-producing Escherichia coli. A total of 198 isolates of E. coli with the ESBL phenotype were studied. Polymerase chain reaction (PCR) amplification of CTX-M genes and amplicon sequencing were performed. The MICs for amoxicillin-clavulanic acid, aztreonam, cefepime, cefotaxime, ceftazidime, ceftibuten, ertapenem, imipenem, mecillinam, meropenem, piperacillin-tazobactam, and temocillin were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Isolates from CTX-M group 9 showed higher susceptibility to the beta-lactam antibiotics tested than isolates belonging to CTX-M group 1. More than 90% of the isolates belonging to CTX-M group 9 were susceptible to amoxicillin-clavulanic acid, ceftazidime, ceftibuten, piperacillin-tazobactam, and temocillin. The susceptibility was high to mecillinam, being 91%, regardless of the CTX-M group. All isolates were susceptible to imipenem and meropenem, and 99% to ertapenem. This study shows significant differences in susceptibility to different beta-lactam antibiotics among the CTX-M-producing E. coli isolates and a significant difference for many antibiotics tested between the CTX-M-producing groups 1 and 9. The good in vitro activity of other beta-lactam antibiotics compared to carbapenems indicate that clinical studies are warranted in order to examine the potential role of these beta-lactam antibiotics in the treatment of infections caused by multiresistant ESBL-producing E. coli.
|
|
| 16. |
- Tärnberg, Maria, et al.
(författare)
-
Molecular identification of blaSHV, blaLEN and blaOKP β-lactamase genes in Klebsiella pneumoniae by bi-directional sequencing of universal SP6- and T7-sequence-tagged blaSHV-PCR amplicons
- 2009
-
Ingår i: Molecular and Cellular Probes. - : Elsevier BV. - 0890-8508 .- 1096-1194. ; 23:3-4, s. 195-200
-
Tidskriftsartikel (refereegranskat)abstract
- Plasmid encoded blaSHV enzymes represent an important sub-group of class A β-lactamases causing an ESBL-phenotype which is increasingly found in Enterobacteriaceae including Klebsiella pneumoniae. The chromosomally encoded β-lactamase blaLEN and blaOKP enzymes, which so far only have been found in K. pneumoniae, do not hydrolyse extended-spectrum cephalosporins. In the present study, multiple displacement amplified DNA derived from 20 K. pneumoniae clinical isolates with a blaSHV-like genotype was used in a universal SHV PCR assay using SP6- (forward) and T7- (reverse) sequence-tagged primers. Identification and differentiation of blaSHV, blaLEN and blaOKP genes was obtained by bi-directional amplicon sequencing using SP6- and T7-specific primers. Three well characterised K. pneumoniae strains having a SHV-genotype were included in the study. The bi-directional amplicon sequencing, covering 800 bp (93%) of the blaSHV, blaLEN and blaOKP enzyme encoding sequences, allowed for an unequivocal discrimination of SHV, LEN and OKP genes. Moreover, sequencing revealed the presence of blaSHV allelic variants in six K. pneumoniae isolates in which the amplicons had to be cloned accordingly. Based on deduced amino-acid sequences, a dendrogram was constructed. Seventeen out of 20 K. pneumoniae isolates with an ESBL-phenotype formed a SHV-like cluster, two were LEN-like, and one isolate was OKP-like. The PCR-based molecular typing method described here enables a rapid, reliable and cost-effective identification and differentiation of blaSHV, blaOKP and blaLEN genes.
|
|
| 17. |
- Woksepp, Hanna, et al.
(författare)
-
High-Resolution Melting-Curve Analysis of Ligation-Mediated Real-Time PCR for Rapid Evaluation of an Epidemiological Outbreak of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli
- 2011
-
Ingår i: Journal of Clinical Microbiology. - : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 49:12, s. 4032-4039
-
Tidskriftsartikel (refereegranskat)abstract
- Methods for the confirmation of nosocomial outbreaks of bacterial pathogens are complex, expensive, and time-consuming. Recently, a method based on ligation-mediated PCR (LM/PCR) using a low denaturation temperature which produces specific melting-profile patterns of DNA products has been described. Our objective was to further develop this method for real-time PCR and high-resolution melting analysis (HRM) in a single-tube system optimized in order to achieve results within 1 day. Following the optimization of LM/PCR for real-time PCR and HRM (LM/HRM), the method was applied for a nosocomial outbreak of extended-spectrum-beta-lactamase (ESBL)-producing and ST131-associated Escherichia coli isolates (n = 15) and control isolates (n = 29), including four previous clusters. The results from LM/HRM were compared to results from pulsed-field gel electrophoresis (PFGE), which served as the gold standard. All isolates from the nosocomial outbreak clustered by LM/HRM, which was confirmed by gel electrophoresis of the LM/PCR products and PFGE. Control isolates that clustered by LM/PCR (n = 4) but not by PFGE were resolved by confirmatory gel electrophoresis. We conclude that LM/HRM is a rapid method for the detection of nosocomial outbreaks of bacterial infections caused by ESBL-producing E. coli strains. It allows the analysis of isolates in a single-tube system within a day, and the discriminatory power is comparable to that of PFGE.
|
|
| 18. |
- Östholm Balkhed, Åse, et al.
(författare)
-
High frequency of co-resistance in CTX-M-producing Escherichia coli to non-beta-lactam antibiotics, with the exception of amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin, in a county of Sweden
- 2013
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 45:4, s. 271-278
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The objective of this study was to investigate the in vitro activity of different antibiotics against CTX-M-producing Escherichia coli in a county of Sweden, and to determine the occurrence of multi-resistance and plasmid- mediated quinolone resistance among these isolates. Methods: A total of 198 isolates of E. coli with extended-spectrum beta-lactamase (ESBL) phenotype and mainly CTX-M genotype were studied. The minimum inhibitory concentrations (MICs) for amikacin, chloramphenicol, ciprofloxacin, colistin, fosfomycin, gentamicin, nalidixic acid, nitrofurantoin, tigecycline, tobramycin, trimethoprim, and trimethoprim-sulfamethoxazole were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Results: Ninety-five percent or more of the isolates were susceptible to amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin. CTX-M group 9 was more susceptible than CTX-M group 1 to ciprofloxacin, gentamicin, and tobramycin. Sixty-eight percent of the isolates were multi-resistant, and the most common multi-resistance pattern was ESBL phenotype with decreased susceptibility to trimethoprim, trimethoprim-sulfamethoxazole, ciprofloxacin, gentamicin, and tobramycin. Only 1 isolate carried a qnrS1 gene, but 37% carried aac(6')-Ib-cr. Conclusions: A high frequency of co-resistance between ESBL-producing E. coli and non-beta-lactam antibiotics was seen. On the other hand, very high susceptibility was seen for amikacin, nitrofurantoin, colistin, tigecycline, and fosfomycin. These data support the replacement of gentamicin and tobramycin, normally used in Sweden, with amikacin, for severe infections.
|
|
| 19. |
- Östholm Balkhed, Åse, et al.
(författare)
-
In vitro susceptibility of CTX-M-producing Escherichia coli to non-beta-lactam agents
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The objective of this study was to investigate the in vitro activity of different antibiotics against CTX-M-producing Escherichia coli, to determine the occurrence of multiresistance and plasmid mediated quinolone resistance among these isolates. Methods: A total of 198 isolates of E. coli with ESBL phenotype and mainly CTX-M genotype, were studied. The MICs for amikacin, chloramphenicol, ciprofloxacin, colistin, fosfomycin, gentamicin, nalidixic acid, nitrofurantoin, tigecycline, tobramycin, trimethoprim and trimethoprim-sulphamethoxazole were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Results: ≥95% of isolates were susceptible to amikacin, nitrofurantoin, colistin, tigecyclin, and fosfomycin. CTX-M group 9 was more susceptible than CTX-M group 1 to ciprofloxacin, gentamicin, and tobramycin. 68% of the isolates were multiresistant, and the most common multi-resistance pattern was ESBL-phenotype with decreased susceptibility to trimethoprim, trimethoprim-sulphamethoxazol, ciprofloxacin, gentamicin and tobramycin. Only one isolate carried a qnrS1-gene, nine isolates carried aac(6’)-Ib-cr. Conclusions: The high frequency of multi-resistance found in this study is alarming and it is urgent to find strategies to limit the emergence and spread of these multi-resistant strains.
|
|
| 20. |
- Östholm Balkhed, Åse, et al.
(författare)
-
Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae and trends in antibiotic consumption in a county of Sweden
- 2010
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa Healthcare. - 0036-5548 .- 1651-1980. ; 42:11-12, s. 831-838
-
Tidskriftsartikel (refereegranskat)abstract
- In the last decade extended-spectrum beta-lactamase (ESBL)-producing bacteria have become an increasing problem. Our aims were to investigate the prevalence of ESBL-producing Enterobacteriaceae and trends in antibiotic use in the county of Ostergotland, Sweden. From 2002 through 2007 there were 224 ESBL-producing Escherichia coli and 23 Klebsiella pneumoniae isolates with an ESBL-phenotype identified among all Enterobacteriaceae isolated at the clinical laboratory. Trends in antibiotic consumption expressed as defined daily doses (DDD) per 1000 inhabitants and day (DID) were studied. The prevalence of ESBL-producing isolates among Enterobacteriaceae in our region is still low (andlt; 1%). Patients with ESBL-producing E. coli increased significantly (p andlt; 0.001) from 5 in y 2002 to 47 in y 2007. CTX-M group 1 was the dominant enzyme group in both E. coli and K. pneumoniae. Antibiotic susceptibility testing of ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole revealed that 58% of E. coli and 50% of K. pneumoniae isolates were multi-resistant. Antibiotic use remained unchanged from 2001 through 2009, but there was a trend towards increased use of drugs with low ESBL selection potential, which was probably due to the increased prevalence of ESBL producers.
|
|
| 21. |
- Östholm Balkhed, Åse, et al.
(författare)
-
Travel-associated faecal colonization with ESBL-producing Enterobacteriaceae : incidence and risk factors
- 2013
-
Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press. - 0305-7453 .- 1460-2091. ; 68:9, s. 2144-2153
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives To study the acquisition of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) among the faecal flora during travel, with a focus on risk factors, antibiotic susceptibility and ESBL-encoding genes.Methods An observational prospective multicentre cohort study of individuals attending vaccination clinics in south-east Sweden was performed, in which the submission of faecal samples and questionnaires before and after travelling outside Scandinavia was requested. Faecal samples were screened for ESBL-PE by culturing on ChromID ESBL and an in-house method. ESBL-PE was confirmed by phenotypic and genotypic methods. Susceptibility testing was performed with the Etest. Individuals who acquired ESBL-PE during travel (travel-associated carriers) were compared with non-carriers regarding risk factors, and unadjusted and adjusted ORs after manual stepwise elimination were calculated using logistic regression.Results Of 262 enrolled individuals, 2.4% were colonized before travel. Among 226 evaluable participants, ESBL-PE was detected in the post-travel samples from 68 (30%) travellers. The most important risk factor in the final model was the geographic area visited: Indian subcontinent (OR 24.8, P < 0.001), Asia (OR 8.63, P < 0.001) and Africa north of the equator (OR 4.94, P = 0.002). Age and gastrointestinal symptoms also affected the risk significantly. Multiresistance was seen in 77 (66%) of the ESBL-PE isolates, predominantly a combination of reduced susceptibility to third-generation cephalosporins, trimethoprim/sulfamethoxazole and aminoglycosides. The most common species and ESBL-encoding gene were Escherichia coli (90%) and CTX-M (73%), respectively.Conclusion Acquisition of multiresistant ESBL-PE among the faecal flora during international travel is common. The geographical area visited has the highest impact on ESBL-PE acquisition.
|
|
