| 1. |
- Lindqvist, Maria, et al.
(författare)
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Genetic relatedness of multi-resistant methicillin-susceptible Staphylococcus aureus in southeast Sweden
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)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.
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| 2. |
- Widerström, Micael, 1958-, et al.
(författare)
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Heterogeneity of Staphylococcus epidermidis in prosthetic joint infections : time to reevaluate microbiological criteria?
- 2022
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer. - 0934-9723 .- 1435-4373. ; 41, s. 87-97
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Tidskriftsartikel (refereegranskat)abstract
- Prosthetic joint infection (PJI) is a feared and challenging to diagnose complication after arthroplasty, with Staphylococcus epidermidis as the major pathogen. One important criteria to define PJI is the detection of phenotypically indistinguishable microorganisms with identical antibiotic susceptibility pattern in at least two different samples. However, owing to phenotypical variation within genetic clones and clonal variation within a phenotype, the criteria may be ambiguous. We investigated the extent of diversity among coagulase-negative staphylococci (CoNS) in PJI and characterised S. epidermidis isolates from PJI samples, specifically multiple S. epidermidis isolates identified in individual PJI patients. We performed a retrospective cohort study on 62 consecutive patients with PJI caused by CoNS from two hospitals in Northern Sweden. In 16/62 (26%) PJIs, multiple S. epidermidis isolates were available for whole-genome analyses. Hospital-adapted multidrug-resistant genetic clones of S. epidermidis were identified in samples from 40/62 (65%) of the patients using a combination of pulsed-field gel electrophoresis and multilocus sequence typing. Whole-genome sequencing showed the presence of multiple sequence types (STs) in 7/16 (44%) PJIs where multiple S. epidermidis isolates were available. Within-patient phenotypical variation in the antibiotic susceptibility and/or whole-genome antibiotic resistance gene content was frequent (11/16, 69%) among isolates with the same ST. The results highlight the ambiguity of S. epidermidis phenotypic characterisation as a diagnostic method in PJI and call for larger systematic studies for determining the frequency of CoNS diversity in PJIs, the implications of such diversity for microbiological diagnostics, and the therapeutic outcomes in patients.
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| 3. |
- Baig, Sharmin, et al.
(författare)
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Evolution and Population Dynamics of Clonal Complex 152 Community-Associated Methicillin-Resistant Staphylococcus aureus
- 2020
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Ingår i: mSphere. - : AMER SOC MICROBIOLOGY. - 2379-5042. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Since the late 1990s, changes in the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) were recognized with the emergence of community-associated MRSA (CA-MRSA). CA-MRSA belonging to clonal complex 152 (CC152), carrying the small staphylococcal cassette chromosome mec (SCCmec) type V and encoding the Panton-Valentine leukocidin (PVL), has been observed in Europe. The aim of this study was to investigate its origin, evolution, and dissemination. Whole-genome sequencing was performed on a global collection of 149 CC152 isolates spanning 20 years (93 methicillin-susceptible S. aureus [MSSA] and 56 MRSA isolates). Core genome phylogeny, Bayesian inference, in silico resistance analyses, and genomic characterization were applied. Phylogenetic analysis revealed two major distinct clades, one dominated by MSSA and the other populated only by MRSA. The MSSA isolates were predominately from sub-Saharan Africa, whereas MRSA was almost exclusively from Europe. The European MRSA isolates all harbored an SCCmec type V (5C2&5) element, whereas other SCCmec elements were sporadically detected in MRSA from the otherwise MSSA-dominated clade, including SCCmec types IV (2B), V (5C2), and XIII (9A). In total, 93% of the studied CC152 isolates were PVL positive. Bayesian coalescent inference suggests an emergence of the European CC152-MRSA in the 1990s, while the CC152 lineage dates back to the 1970s. The CA-MRSA CC152 clone mimics the European CC80 CA-MRSA lineage by its emergence from a PVL-positive MSSA ancestor from North Africa or Europe. The CC152 lineage has acquired SCCmec several times, but acquisition of SCCmec type V (5C2&5) seems associated with expansion of MRSA CC152 in Europe. IMPORTANCE Understanding the evolution of CA-MRSA is important in light of the increasing importance of this reservoir in the dissemination of MRSA. Here, we highlight the story of the CA-MRSA CC152 lineage using whole-genome sequencing on an international collection of CC152. We show that the evolution of this lineage is novel and that antibiotic usage may have the potential to select for the phage-encoded Panton-Valentine leukocidin. The diversity of the strains correlated highly to geography, with higher level of resistance observed among the European MRSA isolates. The mobility of the SCCmec element is mandatory for the emergence of novel MRSA lineages, and we show here distinct acquisitions, one of which is linked to the successful clone found throughout Europe today.
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