The presence or absence of an implant has a major impact on the type of joint infection therapy. Thus, the aim of this study was the examination of potential differences in the spectrum of pathogens ...in patients with periprosthetic joint infections (PJI) as compared to patients with native joint infections (NJI).
In this retrospective study, we evaluated culture-positive synovial fluid samples of 192 consecutive patients obtained from January 2018 to January 2020 in a tertiary care university hospital. For metrically distributed parameters, Mann-Whitney U was used for comparison between groups. In case of nominal data, crosstabs and Chi-squared tests were implemented.
Overall, 132 patients suffered from periprosthetic joint infections and 60 patients had infections of native joints. The most commonly isolated bacteria were coagulase-negative Staphylococci (CNS, 28%), followed by Staphylococcus aureus (S. aureus, 26.7%), and other bacteria, such as Streptococci (26.3%). We observed a significant dependence between the types of bacteria and the presence of a joint replacement (p < 0.05). Accordingly, detections of CNS occurred 2.5-fold more frequently in prosthetic as compared to native joint infections (33.9% vs. 13.4% p < 0.05). In contrast, S. aureus was observed 3.2-fold more often in NJIs as compared to PJIs (52.2% vs. 16.4%, p < 0.05).
The pathogen spectra of periprosthetic and native joint infections differ considerably. However, CNS and S. aureus are the predominant microorganisms in both, PJIs and NJIs, which may guide antimicrobial therapy until microbiologic specification of the causative pathogen.
Rapid molecular identification of carbapenemase genes in Gram-negative bacteria is crucial for infection control and prevention, surveillance and for epidemiological purposes. Furthermore, it may ...have a significant impact upon determining the appropriate initial treatment and greatly benefit for critically ill patients. A novel oligonucleotide microarray-based assay was developed to simultaneously detect genes encoding clinically important carbapenemases as well as selected extended (ESBL) and narrow spectrum (NSBL) beta-lactamases directly from clonal culture material within few hours. Additionally, a panel of species specific markers was included to identify Escherichia coli, Pseudomonas aeruginosa, Citrobacter freundii/braakii, Klebsiella pneumoniae and Acinetobacter baumannii. The assay was tested using a panel of 117 isolates collected from urinary, blood and stool samples. For these isolates, phenotypic identifications and susceptibility tests were available. An independent detection of carbapenemase, ESBL and NSBL genes was carried out by various external reference laboratories using PCR methods. In direct comparison, the microarray correctly identified 98.2% of the covered carbapenemase genes. This included blaVIM (13 out of 13), blaGIM (2/2), blaKPC (27/27), blaNDM (5/5), blaIMP-2/4/7/8/13/14/15/16/31 (10/10), blaOXA-23 (12/13), blaOXA-40-group (7/7), blaOXA-48-group (32/33), blaOXA-51 (1/1) and blaOXA-58 (1/1). Furthermore, the test correctly identified additional beta-lactamases blaOXA-1 (16/16), blaOXA-2 (4/4), blaOXA-9 (33/33), OXA-10 (3/3), blaOXA-51 (25/25), blaOXA-58 (2/2), CTX-M1/M15 (17/17) and blaVIM (1/1). In direct comparison to phenotypical identification obtained by VITEK or MALDI-TOF systems, 114 of 117 (97.4%) isolates, including Acinetobacter baumannii (28/28), Enterobacter spec. (5/5), Escherichia coli (4/4), Klebsiella pneumoniae (62/63), Klebsiella oxytoca (0/2), Pseudomonas aeruginosa (12/12), Citrobacter freundii (1/1) and Citrobacter braakii (2/2), were correctly identified by a panel of species specific probes. This assay might be easily extended, adapted and transferred to point of care platforms enabling fast surveillance, rapid detection and appropriate early treatment of infections caused by multiresistant Gram-negative bacteria.
ST239-MRSA-III is probably the oldest truly pandemic MRSA strain, circulating in many countries since the 1970s. It is still frequently isolated in some parts of the world although it has been ...replaced by other MRSA strains in, e.g., most of Europe. Previous genotyping work (Harris et al.,
2010
; Castillo-Ramírez et al.,
2012
) suggested a split in geographically defined clades. In the present study, a collection of 184 ST239-MRSA-III isolates, mainly from countries not covered by the previous studies were characterized using two DNA microarrays (i) targeting an extensive range of typing markers, virulence and resistance genes and (ii) a SCC
mec
subtyping array. Thirty additional isolates underwent whole-genome sequencing (WGS) and, together with published WGS data for 215 ST239-MRSA-III isolates, were analyzed using
in-silico
analysis for comparison with the microarray data and with special regard to variation within SCC
mec
elements. This permitted the assignment of isolates and sequences to 39 different SCC
mec
III subtypes, and to three major and several minor clades. One clade, characterized by the integration of a transposon into
nsaB
and by the loss of
fnbB
and
splE
was detected among isolates from Turkey, Romania and other Eastern European countries, Russia, Pakistan, and (mainly Northern) China. Another clade, harboring
sasX/sesI
is widespread in South-East Asia including China/Hong Kong, and surprisingly also in Trinidad & Tobago. A third, related, but
sasX/sesI
-negative clade occurs not only in Latin America but also in Russia and in the Middle East from where it apparently originated and from where it also was transferred to Ireland. Minor clades exist or existed in Western Europe and Greece, in Portugal, in Australia and New Zealand as well as in the Middle East. Isolates from countries where this strain is not epidemic (such as Germany) frequently are associated with foreign travel and/or hospitalization abroad. The wide dissemination of this strain and the fact that it was able to cause a hospital-borne pandemic that lasted nearly 50 years emphasizes the need for stringent infection prevention and control and admission screening.
Abstract Among 323 specimens from male patients with symptoms of non-gonococcal urethritis, Mycoplasma genitalium was detected in 19 samples by real-time PCR. Mutations of 23S rRNA gene associated ...with macrolide resistance were confirmed in 10 strains. Amino acid changes at positions 81 and 83 of ParC protein were demonstrated indicating quinolone resistance of two strains.
As culture‐negative implant‐associated infection denote a diagnostic challenge, sonicate fluid cultures of the explanted endoprosthesis and osteosynthesis components are frequently used. However, the ...effect of antibiotic treatment on pathogen detection by sonication fluid cultures in implant‐associated infection has not been investigated. Thus, the aim of this study was to evaluate the influence of preoperative antibiotic prophylaxis (PAP) and antibiotic therapy (AT) on sonicate fluid cultures in patients with implant‐associated infection. In this retrospective study three groups were compared: (i) standard PAP, (ii) AT for at least one day, and (iii) no antibiotics before surgery. For the inclusion criteria, an established diagnostic protocol for implant‐associated infection was used. Sonicate fluid cultures were validated by corresponding microbiological and histopathological samples. In 90 patients with single and multiple infections, 114 pathogens were detected. The detection rate by sonicate fluid cultures in patients receiving PAP (n = 27, 29 pathogens), AT before surgery (n = 33, 48 pathogens) and no antibiotics before surgery (n = 30, 37 pathogens) were 86.2%, 81.3%, and 86.5% (p = .778), respectively. Eleven of 114 infectious agents were detected exclusively by sonicate fluid cultures, while conventional tissue culture failed in these cases. PAP and AT do not affect intraoperative cultures in implant‐associated infection. It is therefore not recommended to omit antibiotic prophylaxis in patients with implant‐associated infection. Algorithms including both sonicate fluid cultures and tissue samples should be used for appropriate microbiological diagnosis of implant‐associated infections.
Since 2013, over 100 cases of Mycobacterium chimaera prosthetic valve endocarditis and disseminated disease were notified in Europe and the USA, linked to contaminated heater–cooler units (HCUs) used ...during cardiac surgery. We did a molecular epidemiological investigation to establish the source of these patients' disease.
We included 24 M chimaera isolates from 21 cardiac surgery-related patients in Switzerland, Germany, the Netherlands, and the UK, 218 M chimaera isolates from various types of HCUs in hospitals, from LivaNova (formerly Sorin; London, UK) and Maquet (Rastatt, Germany) brand HCU production sites, and unrelated environmental sources and patients, as well as eight Mycobacterium intracellulare isolates. Isolates were analysed by next-generation whole-genome sequencing using Illumina and Pacific Biosciences technologies, and compared with published M chimaera genomes.
Phylogenetic analysis based on whole-genome sequencing of 250 isolates revealed two major M chimaera groups. Cardiac surgery-related patient isolates were all classified into group 1, in which all, except one, formed a distinct subgroup. This subgroup also comprised isolates from 11 cardiac surgery-related patients reported from the USA, most isolates from LivaNova HCUs, and one from their production site. Isolates from other HCUs and unrelated patients were more widely distributed in the phylogenetic tree.
HCU contamination with M chimaera at the LivaNova factory seems a likely source for cardiothoracic surgery-related severe M chimaera infections diagnosed in Switzerland, Germany, the Netherlands, the UK, the USA, and Australia. Protective measures and heightened clinician awareness are essential to guarantee patient safety.
Partly funded by the EU Horizon 2020 programme, its FP7 programme, the German Center for Infection Research (DZIF), the Swiss National Science Foundation, the Swiss Federal Office of Public Health, and National Institute of Health Research Oxford Health Protection Research Units on Healthcare Associated Infection and Antimicrobial Resistance.
PCR-based 'serotyping' of Legionella pneumophila Thurmer, Alexander; Helbig, Jurgen Herbert; Jacobs, Enno ...
Journal of Medical Microbiology/Journal of medical microbiology,
05/2009, Volume:
58, Issue:
5
Journal Article
Peer reviewed
Open access
Institute of Medical Microbiology and Hygiene, Technische Universität Dresden, Fiedlerstrasse 42, D-01307 Dresden, Germany
Correspondence Paul Christian Lück christian.lueck{at}tu-dresden.de
Received ...December 3, 2008
Accepted January 7, 2009
Currently, several PCR assays based on 16S rRNA and virulence-associated genes are available for detection of Legionella pneumophila . So far, no genotyping method has been published that can discriminate between serogroups and monoclonal subgroups of the most common L. pneumophila serogroup 1. Our first approach was to analyse LPS-associated genes of seven L. pneumophila serogroup 1 strains, and we developed two PCR-based methods specific for serogroup 1. Specific DNA fragments could be amplified from all the serogroup 1 strains ( n =43) including the strains from the American Type Culture Collection. In contrast, none of the strains from serogroups 2–15 ( n =41) contained these specific gene regions. In a second approach, primers specific for the lag-1 gene, encoding an O -acetyltransferase, which is responsible for the presence of the LPS epitope recognized by mAb 3/1, were designed and tested for their ability to differentiate between mAb 3/1-positive and -negative strains. All mAb 3/1-positive strains ( n =30) contained the lag-1 gene, but in turn 4 of 13 tested mAb 3/1-negative strains were also positive in the PCR. Thus, the discrimination between mAb 3/1-positive and mAb 3/1-negative subgroups could not be achieved for all strains. In a third approach, two intergenic regions expected to be specific for monoclonal subgroup Knoxville and closely related subgroups Benidorm/Bellingham were identified and used for selective genotyping. These intergenic regions could not only be amplified in every tested strain belonging to the subgroups Knoxville, Benidorm and Bellingham, but also in some strains of other unrelated subgroups. The two PCR approaches with primers specific for serogroup 1 genes definitely represent a valuable tool in outbreak investigations and for risk assessment. They also might be used for culture-independent diagnosis of legionellosis caused by L. pneumophila serogroup 1.
Abbreviations: ATCC, American Type Culture Collection; SBT, sequence-based typing.
The GenBank/EMBL/DDBJ accession numbers for the LPS synthesis gene sequences of L. pneumophila strains Uppsala 3 and Görlitz 6543 are AM932053 and AM778127, respectively.
A table of the sequences of the primers used for analysis of the LPS synthesis gene sequences in Uppsala 3 and Görlitz 6543 strains is available as supplementary data with the online version of this paper.
The last nationwide surveillance study on neonatal and young infant sepsis due to Group B Streptococci (GBS) and
Escherichia coli
in Germany was conducted between 2009 and 2010. The aim of this study ...is to provide longitudinal epidemiological data on neonatal and young infant sepsis caused by GBS and
E. coli
to reevaluate existing data and to inform clinical decision-making. Every positive blood culture for GBS and
E. coli
within the first 90 days of life that occurred at our center from 2008 until 2018 was identified. The epidemiological, clinical, laboratory, and microbiological data of all affected patients were analyzed through retrospective chart review, along with the pathogen’s antimicrobial susceptibility results. In total, 106 episodes of neonatal sepsis were described; 31% (
n
= 33) being caused by GBS and 69% (
n
= 73) by
E. coli
; 87% of GBS early-onset disease (EOD) cases did not receive intrapartum antibiotic prophylaxis (IAP). Contrary to general trends, the proportion of resistant
E. coli
isolates decreased for all tested antibiotics over time. Coincidentally, antenatal antibiotic use beyond IAP during that period decreased significantly in our center.
Conclusions
: (1) Data at our center suggests at least a regional implementation gap in GBS screening and IAP. (2) The decline in the resistance rate of
E. coli
for all antimicrobial substances might indicate that the reduction of prenatal antibiotics use is beneficial and that neonatal antibiotic stewardship programs should include pregnant women as well.
What is Known:
• GBS screening and intrapartum antibiotic prophylaxis led to a 32%-reduction in GBS disease in Germany with a 0.75 (92:122) ratio of early-onset disease to late-onset disease in 2009–2010.
• Prenatal antibiotic use might increase the risk of E. coli early-onset disease and antibiotic resistances.
What is New:
• The GBS early-onset disease rates were twice as high as those of late-onset disease, the ratio was 1.75 (21:12) in 2008–2018 at our institution. This suggests that there are at least regional implementation gaps in the antenatal GBS screening in Germany.
• We found a decline in E. coli resistance rates over time for all antimicrobial substances. Reduction in use of prenatal antibiotics might be an explanation.
•A common livestock-associated lineage of methicillin-resistant Staphylococcus aureus (MRSA) is currently clonal complex (CC) 398.•SCCmec elements of 100 veterinary and clinical CC398-MRSA isolates ...from Germany and Austria were examined using DNA microarray based assays.•In addition, 589 published SCC and/or genome sequences of CC398-MRSA were analysed.•Fifteen subtypes of SCCmec elements were detected among the 100 CC398 isolates and 41 subtypes could be discerned among the published CC398 sequences.•Several isolates and sequences showed an insertion of a large fragment of CC9 genomic DNA into the CC398 chromosome.•A high prevalence of heavy metal resistance genes, especially of czrC, was observed among CC398-MRSA.
The most common livestock-associated lineage of methicillin-resistant Staphylococcus aureus (MRSA) in Western Europe is currently clonal complex (CC) 398. CC398-MRSA spread extensively across livestock populations in several Western European countries, and livestock-derived CC398-MRSA strains can also be detected in humans. Based on their SCCmec elements, different CC398 strains can be distinguished. SCCmec elements of 100 veterinary and human CC398-MRSA isolates from Germany and Austria were examined using DNA microarray-based assays. In addition, 589 published SCC and/or genome sequences of CC398-MRSA (including both, fully finished and partially assembled sequences) were analysed by mapping them to the probe sequences of the microarrays. Several isolates and sequences showed an insertion of a large fragment of CC9 genomic DNA into the CC398 chromosome. Fifteen subtypes of SCCmec elements were detected among the 100 CC398 isolates and 41 subtypes could be discerned among the published CC398 sequences. Eleven of these were also experimentally detected within our strain collection, while four subtypes identified in the isolates where not found among the sequences. A high prevalence of heavy metal resistance genes, especially of czrC, was observed among CC398-MRSA. A possible co-selection of resistances to antibiotics and zinc/copper supplements in animal feed as well as a spill-over of SCCmec elements that have evolved in CC398-MRSA to other, possibly more virulent and/or medically relevant S. aureus lineages might pose public health problems in future.
Abstract Aim of this study was to determine the incidence and molecular epidemiology of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Germany. E. coli and K. pneumoniae ...isolates from clinical samples which were non-susceptible to carbapenems were collected in laboratories serving 20 hospitals throughout Germany from November 2013 to April 2014. The isolates were tested for the presence of carbapenemases by PCR and phenotypic methods and typed by multilocus sequence typing. Risk factors including a previous hospitalization abroad were analysed. Carbapenemases were detected in 24 isolates from 22 patients out of 464,514 admissions. Carbapenemases included OXA‐48 (n = 14), KPC‐2 (n = 8) and NDM‐1 (n = 2). Except for two K. pneumoniae isolates with ST101, all OXA‐48 producing strains belonged to different clones. In contrast, half of KPC‐2 producing K. pneumoniae were of ST258 and both NDM‐1 producing strains were of ST11. Compared to carbapenem-susceptible controls, patients with carbapenemase-producing strains differed by a significantly higher proportion of males, a higher proportion of isolates from wound samples and a more frequent previous stay abroad in univariate analysis. This multicentre study demonstrated an incidence of carbapenemase-producing E. coli and K. pneumoniae from clinical samples in Germany of 0.047 cases per 1000 admissions. OXA‐48 was more frequent than KPC‐2 and NDM‐1 and showed a multiclonal background.
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