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    An epidemic CC1-MRSA-IV clone yields false-negative test results in molecular MRSA identification assays: a note of caution, Austria, Germany, Ireland, 2020
    (Stockholm : European Centre for Disease Prevention and Control, 2020) Monecke, Stefan; König, Elisabeth; Earls, Megan R.; Leitner, Eva; Müller, Elke; Wagner, Gabriel E.; Poitz, David M.; Jatzwauk, Lutz; Vremerǎ, Teodora; Dorneanu, Olivia S.; Simbeck, Alexandra; Ambrosch, Andreas; Zollner-Schwetz, Ines; Krause, Robert; Ruppitsch, Werner; Schneider-Brachert, Wulf; Coleman, David C.; Steinmetz, Ivo; Ehricht, Ralf
    We investigated why a clinical meticillin-resistant Staphylococcus aureus (MRSA) isolate yielded false-negative results with some commercial PCR tests for MRSA detection. We found that an epidemic European CC1-MRSA-IV clone generally exhibits this behaviour. The failure of the assays was attributable to a large insertion in the orfX/SCCmec integration site. To ensure the reliability of molecular MRSA tests, it is vital to monitor emergence of new SCCmec types and junction sites.
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    Characterization of Staphylococci and Streptococci Isolated from Milk of Bovides with Mastitis in Egypt
    (Basel : MDPI, 2020) Ahmed, Wedad; Neubauer, Heinrich; Tomaso, Herbert; El Hofy, Fatma Ibrahim; Monecke, Stefan; Abdeltawab, Ashraf Awad; Hotzel, Helmut
    The aim of this study was to characterize staphylococci and streptococci in milk from Egyptian bovides. In total, 50 milk samples were collected from localities in the Nile Delta region of Egypt. Isolates were cultivated, identified using matrix-assisted laser desorption/ionization time-offlight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistanceassociated genes. Thirty-eight Staphylococcus isolates and six Streptococcus isolates could be cultivated. Staphylococcus aureus isolates revealed a high resistance rate to penicillin, ampicillin, clindamycin, and erythromycin. The mecA gene defining methicillin-resistant Staphylococcus aureus, erm(C) and aac-aphD genes was found in 87.5% of each. Coagulase-negative staphylococci showed a high prevalence of mecA, blaZ and tetK genes. Other resistance-associated genes were found. All Streptococcus dysgalactiae isolates carried blaZ, erm(A), erm(B), erm(C) and lnuA genes, while Streptococcus suis harbored erm(C), aphA-3, tetL and tetM genes, additionally. In Streptococcus gallolyticus, most of these genes were found. The Streptococcus agalactiae isolate harbored blaZ, erm(B), erm(C), lnuA, tetK, tetL and tetM genes. Streptococcus agalactiae isolate was analyzed by DNA microarray analysis. It was determined as sequence type 14, belonging to clonal complex 19 and represented capsule type VI. Pilus and cell wall protein genes, pavA, cadD and emrB/qacA genes were identified by microarray analysis. © 2020 by the authors.
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    Phenotypic and Molecular Detection of Biofilm Formation in Staphylococcus aureus Isolated from Different Sources in Algeria
    (Basel : MDPI, 2020) Achek, Rachid; Hotzel, Helmut; Nabi, Ibrahim; Kechida, Souad; Mami, Djamila; Didouh, Nassima; Tomaso, Herbert; Neubauer, Heinrich; Ehricht, Ralf; Monecke, Stefan; El-Adawy, Hosny
    Staphylococcus aureus is an opportunistic bacterium causing a wide variety of diseases. Biofilm formation of Staphylococcus aureus is of primary public and animal health concern. The purposes of the present study were to investigate the ability of Staphylococcus aureus isolated from animals, humans, and food samples to form biofilms and to screen for the presence of biofilmassociated and regulatory genes. In total, 55 Staphylococcus aureus isolated from sheep mastitis cases (n = 28), humans (n = 19), and from food matrices (n = 8) were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The ability of Staphylococcus aureus for slime production and biofilm formation was determined quantitatively. A DNA microarray examination was performed to detect adhesion genes (icaACD and biofilmassociated protein gene (bap)), genes encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), regulatory genes (accessory gene regulator (agr) and staphylococcal accessory regulator (sarA)), and the staphylococcal cassette chromosome mec elements (SCCmec). Out of 55 Staphylococcus aureus isolates, 39 (71.0%) and 23 (41.8%) were producing slime and biofilm, respectively. All Staphylococcus aureus strains isolated from food showed biofilm formation ability. 52.6% of the Staphylococcus aureus strains isolated from sheep with mastitis, and 17.9% of isolates from humans, were able to form a biofilm. Microarray analysis typed the Staphylococcus aureus into 15 clonal complexes. Among all Staphylococcus aureus isolates, four of the human isolates (21.1%) harbored the mecA gene (SCCmec type IV) typed into 2 clonal complexes (CC22-MRSA-IV and CC80-MRSA-IV) and were considered as methicillin-resistant, while two of them were slime-producing. None of the isolates from sheep with mastitis harbored the cna gene which is associated with biofilm production. The fnbB gene was found in 100%, 60% and 40% of biofilm-producing Staphylococcus aureus isolated from food, humans, and sheep with mastitis, respectively. Three agr groups were present and agr group III was predominant with 43.6%, followed by agr group I (38.2%), and agr group II (18.2%). This study revealed the capacity of Staphylococcus aureus isolates to form biofilms and highlighted the genetic background displayed by Staphylococcus aureus isolates from different sources in Algeria. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
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    Characterization of antibiotic and biocide resistance genes and virulence factors of staphylococcus species associated with bovine mastitis in Rwanda
    (Basel : MDPI AG, 2020) Antók, Fruzsina Irén; Mayrhofer, Rosa; Marbach, Helene; Masengesho, Jean Claude; Keinprecht, Helga; Nyirimbuga, Vedaste; Fischer, Otto; Lepuschitz, Sarah; Ruppitsch, Werner; Ehling-Schulz, Monika; Feßler, Andrea T.; Schwarz, Stefan; Monecke, Stefan; Ehricht, Ralf; Grunert, Tom; Spergser, Joachim; Loncaric, Igor
    The present study was conducted from July to August 2018 on milk samples taken at dairy farms in the Northern Province and Kigali District of Rwanda in order to identify Staphylococcus spp. associated with bovine intramammary infection. A total of 161 staphylococcal isolates originating from quarter milk samples of 112 crossbred dairy cattle were included in the study. Antimicrobial susceptibility testing was performed and isolates were examined for the presence of various resistance genes. Staphylococcus aureus isolates were also analyzed for the presence of virulence factors, genotyped by spa typing and further phenotypically subtyped for capsule expression using Fourier Transform Infrared (FTIR) spectroscopy. Selected S. aureus were characterized using DNA microarray technology, multi-locus sequence typing (MLST) and whole-genome sequencing. All mecA-positive staphylococci were further genotyped using dru typing. In total, 14 different staphylococcal species were detected, with S. aureus being most prevalent (26.7%), followed by S. xylosus (22.4%) and S. haemolyticus (14.9%). A high number of isolates was resistant to penicillin and tetracycline. Various antimicrobial and biocide resistance genes were detected. Among S. aureus, the Panton–Valentine leukocidin (PVL) genes, as well as bovine leukocidin (LukM/LukF-P83) genes, were detected in two and three isolates, respectively, of which two also carried the toxic shock syndrome toxin gene tsst-1 bovine variant. t1236 was the predominant spa type. FTIR-based capsule serotyping revealed a high prevalence of non-encapsulated S. aureus isolates (89.5%). The majority of the selected S. aureus isolates belonged to clonal complex (CC) 97 which was determined using DNA microarray based assignment. Three new MLST sequence types were detected. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
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    Staphylococcus aureus and methicillin resistant S. Aureus in nepalese primates: Resistance to antimicrobials, virulence, and genetic lineages
    (Basel : MDPI AG, 2020) Roberts, Marilyn C.; Joshi, Prabhu Raj; Monecke, Stefan; Ehricht, Ralf; Müller, Elke; Gawlik, Darius; Diezel, Celia; Braun, Sascha D.; Paudel, Saroj; Acharya, Mahesh; Khanal, Laxman; Koju, Narayan P.; Chalise, Mukesh; Kyes, Randall C.
    Staphylococcus aureus is a ubiquitous pathogen and colonizer in humans and animals. There are few studies on the molecular epidemiology of S. aureus in wild monkeys and apes. S. aureus carriage in rhesus macaques (Macaca mulatta) and Assam macaques (Macaca assamensis) is a species that has not previously been sampled and lives in remote environments with limited human contact. Forty Staphylococcus aureus isolates including 33 methicillin-susceptible S. aureus (MSSA) and seven methicillin-resistant S. aureus (MRSA) were characterized. Thirty-four isolates were from rhesus macaques and six isolates (five MSSA, one MRSA) were from Assam macaques. Isolates were characterized using StaphyType DNA microarrays. Five of the MRSA including one from Assam macaque were CC22 MRSA-IV (PVL+/tst+), which is a strain previously identified in Nepalese rhesus. One MRSA each were CC6 MRSA-IV and CC772 MRSA-V (PVL+). One MSSA each belonged to CC15, CC96, and CC2990. Six MRSA isolates carried the blaZ, while ten known CC isolates (seven MRSA, three MSSA) carried a variety of genes including aacA-aphD, aphA3, erm(C), mph(C), dfrA, msrA, and/or sat genes. The other 30 MSSA isolates belonged to 17 novel clonal complexes, carried no antibiotic resistance genes, lacked Panton–Valentine Leukocidin (PVL), and most examined exotoxin genes. Four clonal complexes carried egc enterotoxin genes, and four harbored edinB, which is an exfoliative toxin homologue. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
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    Editorial: New insights and updates on the molecular epidemiology and antimicrobial resistance of MRSA in humans in the whole-genome sequencing era
    (Lausanne : Frontiers Media, 2019) Coleman, David C.; Shore, Anna C.; Goering, Richard V.; Monecke, Stefan
    [No abstract available]
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    Fast, economic and simultaneous identification of clinically relevant Gram-negative species with multiplex real-time PCR
    (London : Future Medicine Ltd, 2019) Weiss, Daniel; Gawlik, Darius; Hotzel, Helmut; Engelmann, Ines; Mueller, Elke; Slickers, Peter; Braun, Sascha D.; Monecke, Stefan; Ehricht, Ralf
    Aim: A newly designed multiplex real-time PCR (rt-PCR) was validated to detect four clinically relevant Gram-negative bacteria (Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa). Materials & methods: Serial dilutions of genomic DNA were used to determine the limit of detection. Colony PCR was performed with isolates of the four selected species and other species as negative controls. Isolates were characterized genotypically and phenotypically to evaluate the assay. Results: Specific signals of all target genes were detected with diluted templates comprising ten genomic equivalents. Using colony rt-PCR, all isolates of the target species were identified correctly. All negative control isolates were negative. Conclusion: The genes gad, basC, khe and ecfX can reliably identify these four species via multiplex colony rt-PCR. © 2018 Daniel Weiss.
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    A novel multidrug-resistant PVL-negative CC1-MRSA-IV clone emerging in Ireland and Germany likely originated in South-Eastern Europe
    (Amsterdam [u.a.] : Elsevier Science, 2019) Earls, Megan R.; Shore, Anna C.; Brennan, Gráinne I.; Simbeck, Alexandra; Schneider-Brachert, Wulf; Vremerǎ, Teodora; Dorneanu, Olivia S.; Slickers, Peter; Ehricht, Ralf; Monecke, Stefan; Coleman, David C.
    This study investigated the recent emergence of multidrug-resistant Panton-Valentine leukocidin (PVL)-negative CC1-MRSA-IV in Ireland and Germany. Ten CC1-MSSA and 139 CC1-MRSA isolates recovered in Ireland between 2004 and 2017 were investigated. These were compared to 21 German CC1-MRSA, 10 Romanian CC1-MSSA, five Romanian CC1-MRSA and two UAE CC1-MRSA, which were selected from an extensive global database, based on similar DNA microarray profiles to the Irish isolates. All isolates subsequently underwent whole-genome sequencing, core-genome single nucleotide polymorphism (cgSNP) analysis and enhanced SCCmec subtyping. Two PVL-negative clades (A and B1) were identified among four main clades. Clade A included 20 German isolates, 119 Irish isolates, and all Romanian MRSA and MSSA isolates, the latter of which differed from clade A MRSA by 47–130 cgSNPs. Eighty-six Irish clade A isolates formed a tight subclade (A1) exhibiting 0–49 pairwise cgSNPs, 80 of which harboured a 46 kb conjugative plasmid carrying both ileS2, encoding high-level mupirocin resistance, and qacA, encoding chlorhexidine resistance. The resistance genes aadE, aphA3 and sat were detected in all clade A MRSA and the majority (8/10) of clade A MSSA isolates. None of the clade A isolates harboured any enterotoxin genes other than seh, which is universally present in CC1. Clade B1 included the remaining German isolate, 17 Irish isolates and the two UAE isolates, all of which corresponded to the Western Australia MRSA-1 (WA MRSA-1) clone based on genotypic characteristics. MRSA within clades A and B1 differed by 188 cgSNPs and clade-specific SCCmec characteristics were identified, indicating independent acquisition of the SCCmec element. This study demonstrated the existence of a European PVL-negative CC1-MRSA-IV clone that is distinctly different from the well-defined PVL-negative CC1-MRSA-IV clone, WA MRSA-1. Furthermore, cgSNP analysis revealed that this newly defined clone may have originated in South-Eastern Europe, before spreading to both Ireland and Germany. © 2019 The Authors
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    Urban brown rats (Rattus norvegicus) as possible source of multidrug-resistant Enterobacteriaceae and meticillin-resistant Staphylococcus spp., Vienna, Austria, 2016 and 2017
    (Stockholm : European Centre for Disease Prevention and Control, 2019) Desvars-Larrive, Amélie; Ruppitsch, Werner; Lepuschitz, Sarah; Szostak, Michael P.; Spergser, Joachim; Feßler, Andrea T.; Schwarz, Stefan; Monecke, Stefan; Ehricht, Ralf; Walzer, Chris; Loncaric, Igor
    Background: Brown rats (Rattus norvegicus) are an important wildlife species in cities, where they live in close proximity to humans. However, few studies have investigated their role as reservoir of antimicrobial-resistant bacteria. Aim: We intended to determine whether urban rats at two highly frequented sites in Vienna, Austria, carry extended-spectrum β-lactamase-producing Enterobacteriaceae, fluoroquinolone-resistant Enterobacteriaceae and meticillin-resistant (MR) Staphylococcus spp. (MRS). Methods: We surveyed the presence of antimicrobial resistance in 62 urban brown rats captured in 2016 and 2017 in Vienna, Austria. Intestinal and nasopharyngeal samples were cultured on selective media. We character-ised the isolates and their antimicrobial properties using microbiological and genetic methods including disk diffusion, microarray analysis, sequencing, and detection and characterisation of plasmids. Results: Eight multidrug-resistant Escherichia coli and two extensively drug-resistant New Delhi metallo-β-lactamases-1 (NDM-1)-producing Enterobacter xiangfangensis ST114 (En. cloacae complex) were isolated from nine of 62 rats. Nine Enterobacteriaceae isolates harboured the blaCTX-M gene and one carried a plasmid-encoded ampC gene (blaCMY-2). Forty-four MRS were isolated from 37 rats; they belonged to seven different staphylococcal species: S. fleuret-tii, S. sciuri, S. aureus, S. pseudintermedius, S. epidermidis, S. haemolyticus (all mecA-positive) and mecC-positive S. xylosus. Conclusion: Our findings suggest that brown rats in cities are a potential source of multidrug-resistant bacteria, including carbapenem-resistant En. xiangfangensis ST114. Considering the increasing worldwide urbanisation, rodent control remains an important priority for health in modern cities. © 2019, European Centre for Disease Prevention and Control (ECDC). All rights reserved.
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    Caspase-1 inflammasome activity in patients with Staphylococcus aureus bacteremia
    (Oxford : Wiley-Blackwell, 2019) Rasmussen, Gunlög; Idosa, Berhane Asfaw; Bäckman, Anders; Monecke, Stefan; Strålin, Kristoffer; Särndahl, Eva; Söderquist, Bo
    The inflammasome is a multiprotein complex that mediates caspase-1 activation with subsequent maturation of the proinflammatory cytokines IL-1ß and IL-18. The NLRP3 inflammasome is known to be activated by Staphylococcus aureus, one of the leading causes of bacteremia worldwide. Inflammasome activation and regulation in response to bacterial infection have been found to be of importance for a balanced host immune response. However, inflammasome signaling in vivo in humans initiated by S. aureus is currently sparsely studied. This study therefore aimed to investigate NLRP3 inflammasome activity in 20 patients with S. aureus bacteremia (SAB), by repeated measurement during the first week of bacteremia, compared with controls. Caspase-1 activity was measured in monocytes and neutrophils by flow cytometry detecting FLICA (fluorescent-labeled inhibitor of caspase-1), while IL-1ß and IL-18 was measured by Luminex and ELISA, respectively. As a measure of inflammasome priming, messenger RNA (mRNA) expression of NLRP3, CASP1 (procaspase-1), and IL1B (pro-IL-1ß) was analyzed by quantitative PCR. We found induced caspase-1 activity in innate immune cells with subsequent release of IL-18 in patients during the acute phase of bacteremia, indicating activation of the inflammasome. There was substantial interindividual variation in caspase-1 activity between patients with SAB. We also found an altered inflammasome priming with low mRNA levels of NLRP3 accompanied by elevated mRNA levels of IL1B. This increased knowledge of the individual host immune response in SAB could provide support in the effort to optimize management and treatment of each individual patient. © 2019 The Authors. Microbiology and Immunology published by The Societies and John Wiley & Sons Australia, Ltd