| 1. |
- Lindqvist, Maria, et al.
(author)
-
Long-term persistence of a multi-resistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) clone at a university hospital in southeast Sweden, without further transmission within the region
- 2015
-
In: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Verlag (Germany). - 0934-9723 .- 1435-4373. ; 34:7, s. 1415-1422
-
Journal article (peer-reviewed)abstract
- The objective of this study was to characterise isolates of methicillin-susceptible Staphylococcus aureus (MSSA) with resistance to clindamycin and/or tobramycin in southeast Sweden, including the previously described ECT-R clone (t002) found in Östergotland County, focusing on clonal relatedness, virulence determinants and existence of staphylococcal cassette chromosome (SCC) mec remnants. MSSA isolates with resistance to clindamycin and/or tobramycin were collected from the three county councils in southeast Sweden and investigated with spa typing, polymerase chain reaction (PCR) targeting the SCCmec right extremity junction (MREJ) and DNA microarray technology. The 98 isolates were divided into 40 spa types, and by microarray clustered in 17 multi-locus sequence typing (MLST) clonal complexes (MLST-CCs). All isolates with combined resistance to clindamycin and tobramycin (n = 12) from Östergotland County and two additional isolates (clindamycin-R) were designated as spa type t002, MREJ type ii and were clustered in CC5, together with a representative isolate of the ECT-R clone, indicating the clones persistence. These isolates also carried several genes encoding exotoxins, Q9XB68-dcs and qacC. Of the isolates in CC15, 83 % (25/30) were tobramycin-resistant and were designated spa type t084. Of these, 68 % (17/25) were isolated from new-borns in all three counties. The persistence of the ECT-R clone in Östergotland County, although not found in any other county in the region, carrying certain virulence factors that possibly enhance its survival in the hospital environment, highlights the fact that basic hygiene guidelines must be maintained even when MRSA prevalence is low.
|
|
| 2. |
- Lindqvist, Maria, 1983-
(author)
-
Epidemiological and molecular biological studies of multi-resistant methicillin-susceptible Staphylococcus aureus
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- Antibiotic resistance is increasingly recognised as a major problem and threat. During the last decades Gram-positive bacteria in general, and methicillin-resistant Staphylococcus aureus (MRSA) in particular, have been in focus both concerning matters of antibiotic resistance and as pathogens causing health care-associated (nosocomial) infections. In contrast to MRSA, studies on clonal distribution of methicillin-susceptible S. aureus (MSSA) are scarce. However, interest in MSSA has increased since it was shown that MRSA emerges from susceptible backgrounds by acquisition of a staphylococcal cassette chromosome element, carrying the mecA gene encoding methicillin-resistance (SCCmec).In an outbreak investigation of MRSA in Östergötland County, Sweden, in 2005, a high incidence of MSSA isolates with concomitant resistance to erythromycin, clindamycin and tobramycin (ECT-R) was detected. Analysis showed that 91 % of the investigated isolates were genetically related (clonal). The ECT-R clone was divided into four different but closely related patterns with pulsed-field gel electrophoresis (PFGE), and was designated spa type t002. Whole genome sequencing revealed that the ECT-R clone carried a pseudo-SCC element estimated to be 12 kb in size, showing a resemblance of more than 99 % with the SCCmec type II element of MRSA strain N315 (New York/Japan clone). This suggested a probable derivation from a highly successful MRSA strain, which had partially excised its SCCmec. The clonal outbreak was concentrated in eight hospital departments and two primary care centres, all located in the city of Linköping. Despite a high exchange of patients with the hospitals in the neighbouring counties in southeast Sweden (Jönköping- and Kalmar County), the ECT-R clone seemed to be limited to Östergötland County. However, a tobramycin-resistant clone predominated by isolates of spa type t084 was found in all three counties in southeast Sweden, and in particular among newborns, suggesting inter-hospital transmission.The ECT-R clone has survived as an abundant MSSA clone for a decade in Östergötland County, which indicates an insufficiency in the maintenance of basic hygiene guidelines, and that the clone probably possesses mechanisms of virulence and transmission that are yet to be discovered.
|
|
| 3. |
- Lindqvist, Maria, et al.
(author)
-
Genetic relatedness of multi-resistant methicillin-susceptible Staphylococcus aureus in southeast Sweden
- 2014
-
Other publication (other academic/artistic)abstract
- Background: A high exchange of patients occurs between the hospitals in southeast Sweden, resulting in a possible transmission of nosocomial pathogens. The objective of this study was to investigate the incidence and possible genetic relatedness of multi-resistant methicillinsusceptible Staphylococcus aureus (MSSA) in the region in general, and in particular the possible persistence and transmission of the ECT-R clone (t002) showing resistance to erythromycin, clindamycin and tobramycin previously found in Östergötland County.Methods: Three groups of S. aureus isolates with different antibiotic resistance profiles, including the ECT-R profile, were collected from the three County Councils in southeast Sweden and investigated with spa typing, real-time PCR targeting the staphylococcal cassette chromosome (SCC) mec right extremity junction (MREJ), and microarray.Results: All isolates with the ECT-R resistance profile (n = 12) from Östergötland County and two additional isolates with another antibiotic resistance profile were designated spa type t002, MREJ type ii, and were clustered in the same clonal cluster (CC) (i.e. CC5) by the microarray result, indicating the persistence of the ECT-R clone. In addition, 60 % of the isolates belonged to CC15 from newborns, with 94 % sharing spa type t084, indicating interhospital transmission.Conclusions: The persistence of the ECT-R clone and the possible transmission of the t084 strain indicate that there is still an insufficiency in the maintenance of basic hygiene guidelines. The ECT-R clone probably possesses mechanisms of virulence and transmission that make it so successful.
|
|
| 4. |
- Samuelsson, Annika, 1964-, et al.
(author)
-
Late onset neonatal sepsis, risk factors and interventions: an analysis of recurrent outbreaks of Serratia marcescens 2006-2011
- 2014
-
In: Journal of Hospital Infection. - : Elsevier. - 0195-6701 .- 1532-2939. ; 86:1, s. 57-63
-
Journal article (peer-reviewed)abstract
- Background: during the period 2006 to 2011 we observed 11 patients with Serratia marcescens sepsis, a total of 47 patients were colonised due to spread of different clones. These recurrent clusters brought about interventions to reduce spread between patients.Aim: to evaluate the effect of stepwise introduced interventions to prevent S marcescens colonisation/sepsis and to analyse risk factors for late onset sepsis (LOS).Methods: to evaluate the interventions an open retrospective observational study was performed. A retrospective case-control study was performed to analyse risk factors for LOS.Findings: main findings of this study were the decrease in S marcescens sepsis and colonisation after the stepwise adoption of hygiene interventions, as well as identifying low gestational age, low birth weight, indwelling central venous or umbilical catheter and ventilator treatment as risk factors for LOS. Compliance to basic hygiene guidelines was the only intervention continuously monitored from late 2007. Compliance increased gradually to a steady high level early 2009. There was a decrease in LOS with S marcescens (LOS-Ser) clustering after the second quarter of 2008. After the first quarter of 2009 we saw a decrease in S marcescens colonisation.Conclusion: We were not able to isolate specific effects of each intervention, but an update of our antibiotic policy probably had effect on the occurrence of LOS-ser. The delayed effect of interventions on S marcescens colonisation was probably due to the time it takes for new routines to have impact, illustrated by the gradual increase in compliance to basic hygiene guidelines.
|
|
| 5. |
- Mernelius, Sara, et al.
(author)
-
Compliance with hygiene guidelines : The effect of a multimodal hygiene intervention and validation of direct observations
- 2013
-
In: American Journal of Infection Control. - : Elsevier. - 0196-6553 .- 1527-3296. ; 41:5, s. E45-E48
-
Journal article (peer-reviewed)abstract
- BackgroundGood compliance with hygiene guidelines is essential to prevent bacterial transmission and health care-associated infections. However, the compliance is usually <50%.MethodsA multimodal and multidisciplinary hygiene intervention was launched once the baseline compliance was determined through direct observations in 4 departments of obstetrics and gynecology. Detailed evaluations of the compliance rates were performed at point of stability (at 80%) and follow-up (3 years after hygiene intervention). Validation of direct observations was performed using blinded double appraisal and multiappraisal.ResultsAt baseline, the compliance with barrier precautions and the dress code at the 4 departments were 39% to 47% and 79% to 98%, respectively. Point of stability was reached approximately 1 year after the hygiene intervention was launched. The compliance with barrier precautions was significantly higher at follow-up compared with baseline in 3 departments. In the validation by double appraisal, 471 of 483 components were judged identical between observers. In the multiappraisal, 95% to 100% of the observers correctly judged the 7 components.ConclusionIt is possible to improve compliance with hygiene guidelines, but, to ensure a long-lasting effect, a continuous focus on barrier precautions is required. Observation is a valid method to monitor compliance.
|
|
| 6. |
- Mernelius, Sara, et al.
(author)
-
The effect of improved compliance with hygiene guidelines on transmission of Staphylococcus aureus to newborn infants: The Swedish Hygiene Intervention and Transmission of S aureus study
- 2013
-
In: American Journal of Infection Control. - : Elsevier. - 0196-6553 .- 1527-3296. ; 41:7, s. 585-590
-
Journal article (peer-reviewed)abstract
- Background: Newborn infants are often colonized with Staphylococcus aureus originating from health care workers (HCWs). We therefore use colonization with S aureus of newborn infants to determine the effect of an improved compliance with hygiene guidelines on bacterial transmission. Methods: Compliance with hygiene guidelines was monitored prior to (baseline) and after (follow-up) a multimodal hygiene intervention in 4 departments of obstetrics and gynecology. spa typing was used to elucidate transmission routes of S aureus collected from newborn infants, mothers, fathers, staff members, and environment. Results: The compliance with hygiene guidelines increased significantly from baseline to follow-up. The transmission of S aureus from HCWs to infants was however not affected. Fathers had the highest colonization rates. Persistent carriage was indicated in 18% of the HCWs. The most commonly isolated spa type was t084, which was not detected in a previous study from the same geographic area. Conclusion: It is possible to substantially improve the compliance with hygiene guidelines, by using multimodal hygiene intervention. The improved compliance did not decrease the transmission of S aureus from sources outside the own family to newborn infants. Furthermore, we show the establishment of a new spa type (t084), which now is very common in our region. Copyright (C) 2013 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
|
|
| 7. |
- Samuelsson, Annika, 1964-
(author)
-
The faecal flora : a source of healthcare-associated infections and antibiotic resistance
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- Healthcare-associated infections (HAI) are important causes of mortality and morbidity, and antibiotic treatment is often necessary. Development and availability of new antibiotics are closely followed by development of resistance among microorganisms. During antibiotic therapy, a fraction of the antibiotic given is found in the gut. The human gut is an important reservoir of bacteria. Microorganisms residing or passing the gut is referred to as the gut flora or microbiota. The results of this thesis showed spread of Enterococcus spp between patients on a general intensive care unit, causing septicaemia. After improved hygiene, reorganisation of rooms and thorough cleaning of the unit, together with revision of antibiotic strategy, the incidence of septicaemia with Enterococcus spp fell. Investigation of patients treated for acute intra-abdominal infections showed a shift in the aerobic faecal flora from antibiotic-susceptible Enterobacteriaceae spp towards Enterococcus faecium, yeasts and species of Enterobacteriaceae more resistant to antibiotics, after antibiotic treatment and hospital care. Investigation of recurrent outbreaks of Serratia marcescens sepsis in patients admitted to a neonatal intensive care unit showed different clones with each outbreak. Multiple hygiene interventions and revision of antibiotic strategy subsequently obviated recurrent outbreaks of sepsis, but spread of S. marcescens was not reduced until compliance with basic hygiene guidelines remained stable above 80%. We also found that low gestational age at birth, ventilator treatment and central venous or umbilical catheters are independent risk factors for late onset sepsis. Investigation of the faecal microbiota in patients with acute appendicitis or diverticulitis revealed that disturbance of the faecal microbiota already existed on admission, with higher numbers of Enterobacteriaceae and less Bacteroides, Faecalibacterium, Ruminococcus and Prevotella prior to antibiotic treatment and hospitalisation, than the control population. After treatment and hospitalisation diversity increased significantly in the diverticulitis group, approaching the healthy controls in composition.
|
|
| 8. |
- Lindqvist, Maria, et al.
(author)
-
Detection and characterisation of SCCmec remnants in multiresistant methicillin-susceptible Staphylococcus aureus causing a clonal outbreak in a Swedish county
- 2012
-
In: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Verlag (Germany). - 0934-9723 .- 1435-4373. ; 31:2, s. 141-147
-
Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate if multiresistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) causing a clonal outbreak in A-stergotland County, Sweden, were derived from methicillin-resistant S. aureus (MRSA) by carrying remnants of SCCmec, and, if so, to characterise this element. A total of 54 MSSA isolates with concomitant resistance to erythromycin, clindamycin and tobramycin from 49 patients (91% clonally related, spa type t002) were investigated with the BD GeneOhm MRSA assay and real-time polymerase chain reaction (PCR) targeting the SCCmec integration site/SCCmec right extremity junction. DNA sequencing of one isolate representing the MR-MSSA outbreak clone was performed by massive parallel 454 pyrosequencing. All isolates that were part of the clonal outbreak carried SCCmec remnants. The DNA sequencing revealed the carriage of a pseudo-SCC element 12 kb in size, with a genomic organisation identical to an SCCmec type I (TM) I (TM) element, except for a 41-kb gap. This study demonstrates the presence of a pseudo-SCC element resembling SCCmec type II among MR-MSSA, suggesting possible derivation from MRSA. The presence of SCCmec remnants should always be considered when SCCmec typing is used for MRSA detection, and may not be suitable in locations with a high prevalence of MR-MSSA, since this might give a high number of false-positive results.
|
|
| 9. |
- Samuelsson, Annika, 1964-, et al.
(author)
-
Changes in the aerobic faecal flora of patients treated with antibiotics for acute intra-abdominal infection
- 2012
-
In: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 44:11, s. 820-827
-
Journal article (peer-reviewed)abstract
- Background: An open observational study was performed to investigate changes in the rectal flora and antibiotic susceptibility among faecal bacteria in patients treated with antibiotics for acute intra-abdominal infection. Methods: One hundred and forty patients with acute intra-abdominal infection requiring antibiotic treatment and hospitalization were included. Eight surgical units from the southern part of Sweden participated, between January 2006 and November 2007. Antibiotic treatments were according to local guidelines. Rectal swabs were obtained on admission (sample 1) and 214 days after the end of antibiotic treatment (sample 2). Aerobic bacteria and yeasts were analysed. The material was divided into 2 groups: 1 group with Enterobacteriaceae and 1 group with non-fermentative Gram-negative bacteria. The susceptibility to antibiotics in each group was compared between samples 1 and 2. Results: The main finding of this study on patients with severe intra-abdominal infections was a shift in the aerobic faecal flora following antibiotic treatment, from Escherichia coli to other more resistant Enterobacteriaceae, Enterococcus faecium, and yeasts. The susceptibility to cephalosporins and piperacillintazobactam decreased in Enterobacteriaceae. Conclusions: Following antibiotic treatment, a shift in the aerobic rectal flora to species with intrinsic antibiotic resistance was observed. This indicates that the emergence of resistance is not due to new mutations, but rather to selection of more resistant species. This should be taken into account when designing treatments for secondary intra-abdominal infections.
|
|
| 10. |
|
|
