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Meyer C, Lucaβen K, Gerson S, Xanthopoulou K, Wille T, Seifert H, Higgins PG. Contribution of RND-Type Efflux Pumps in Reduced Susceptibility to Biocides in Acinetobacter baumannii. Antibiotics (Basel) 2022; 11:1635. [PMID: 36421279 PMCID: PMC9686468 DOI: 10.3390/antibiotics11111635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 07/30/2023] Open
Abstract
Bacterial efflux pumps are among the key mechanisms of resistance against antibiotics and biocides. We investigated whether differential expression levels of the RND-type efflux pumps AdeABC and AdeIJK impacted the susceptibility to commonly used biocides in multidrug-resistant Acinetobacter baumannii. Susceptibility testing and time-kill assays of defined laboratory and clinical A. baumannii strains with different levels of efflux pump expression were performed after exposure to the biocides benzalkonium chloride, chlorhexidine digluconate, ethanol, glucoprotamin, octenidine dihydrochloride, and triclosan. While the impact of efflux pump expression on susceptibility to the biocides was limited, noticeable differences were found in kill curves, where AdeABC expression correlated with greater survival after exposure to benzalkonium chloride, chlorhexidine digluconate, glucoprotamin, and octenidine dihydrochloride. AdeABC expression levels did not impact kill kinetics with ethanol nor triclosan. In conclusion, these data indicate that the overexpression of the RND-type efflux pumps AdeABC and AdeIJK contributes to the survival of A. baumannii when exposed to residual concentrations of biocides.
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Wohlfarth E, Kresken M, Higgins PG, Stefanik D, Wille J, Hafner D, Körber-Irrgang B, Seifert H, Kniehl E, Funke G, Schumacher U, Wichelhaus TA, Hörauf A, Peters G, Becker K, Mellmann A, Weißer H, Siegel E, MacKenzie C, Holfelder M, Eigner U, Schubert S, Podbielski A, Diefenbach A, Göbel U, Straube E, Pfister W, Rödel J, Schneider W, Jantsch J, Ziesing S. The evolution of carbapenem resistance determinants and major epidemiological lineages among carbapenem-resistant Acinetobacter baumannii isolates in Germany, 2010-2019. Int J Antimicrob Agents 2022; 60:106689. [PMID: 36375774 DOI: 10.1016/j.ijantimicag.2022.106689] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 07/03/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022]
Abstract
The aim of this study was to investigate and compare the molecular epidemiology and carbapenem resistance determinants in clinical Acinetobacter baumannii isolates collected during four multicentre surveillance studies conducted by the Paul-Ehrlich-Society for Infection Therapy. Isolates were collected prospectively from hospital in-patients at 17 medical centres in Germany over four periods of three- to six-months starting in October of each of 2010, 2013, 2016 and 2019. Species identification was performed by MALDI-TOF, gyrB multiplex polymerase chain reaction (PCR), and detection of the intrinsic blaOXA-51-like gene. Minimum inhibitory concentrations were determined by broth microdilution. The prevalence of carbapenemase-encoding genes was investigated by OXA-multiplex PCR and whole-genome sequencing. Molecular epidemiology was examined by rep-PCR and core-genome multi-locus sequence typing. A total of 302 A. baumannii isolates were collected. Resistance to imipenem and/or meropenem was detected in 58 isolates (19.2%) from 14 centres. The proportion of carbapenem-resistant isolates increased from 21.3% in 2010 to 33.3% in 2013, and then decreased to 13.8% in 2016 and 12.3% in 2019. Forty-six of these isolates were associated with the international clonal lineage IC2 and five with IC1. The most prevalent carbapenemase gene detected was blaOXA-23-like (n=51). Further carbapenem-resistance determinants were blaOXA-40-like (n=1), blaOXA-58-like (n=3) and blaNDM-1 (n=2). In one isolate, ISAba1 was detected upstream of blaOXA-51-like. In conclusion, IC2 was the most prevalent clonal lineage detected in this study. Interestingly, in Germany, carbapenem resistance seems to have decreased in A. baumannii between 2013 and 2019.
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Seyfert CE, Porten C, Yuan B, Deckarm S, Panter F, Bader C, Coetzee J, Deschner F, Tehrani K, Higgins PG, Seifert H, Marlovits T, Herrmann J, Müller R. Darobactins Exhibiting Superior Antibiotic Activity by Cryo‐EM Structure Guided Biosynthetic Engineering. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202214094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nemec A, Radolfová-Křížová L, Maixnerová M, Nemec M, Shestivska V, Španělová P, Kyselková M, Wilharm G, Higgins PG. Acinetobacter amyesii sp. nov., widespread in the soil and water environment and animals. Int J Syst Evol Microbiol 2022; 72. [PMID: 36282562 DOI: 10.1099/ijsem.0.005642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023] Open
Abstract
We studied a novel taxon of the genus
Acinetobacter
, which comprised six strains collected in Czechia, Germany, Indonesia and Turkey between 2015 and 2021. The organisms were isolated from environmental soil, water samples and cow faeces. Their genome sizes varied between 3.3 and 3.5 Mb, with a G+C content of 40.4–40.8 mol%. Based on genus-wide core genome analysis, the taxon formed a distinct clade, with
Acinetobacter gandensis
being the phylogenetically closest related species. The intrataxon genomic average nucleotide identity based on blast (ANIb) and digital DNA–DNA hybridization (dDDH) values reached 95.3–97.4% and 62.5–77.8 %, respectively, whereas its ANIb/dDDH values against the known
Acinetobacter
type strains were ≤82.7 %/≤25.7 %. Cluster analysis of whole-cell MALDI-TOF mass spectra corroborated the distinctness and cohesiveness of the taxon. The novel strains were non-glucose-oxidizing, non-haemolytic and non-proteolytic, growing at up to 37–41 °C but not at 44 °C and utilizing 8–10 of the 36 carbon sources tested. Growth on glutarate, tricarballylate and at 37 °C combined with the inability to assimilate 4-aminobutyrate and d-malate differentiated them from all validly named
Acinetobacter
species. The inspection of genome sequences in the NCBI database revealed the existence of numerous strains conspecific with this group, which were collected from pig faeces and environmental samples in China. We conclude that the taxon represents an ecologically and geographically widespread species, for which we propose the name Acinetobacter amyesii sp. nov., with ANC 5579T (= CCM 9242T=CCUG 76274T=CNCTC 8134T) as the type strain.
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Xanthopoulou K, Imirzalioglu C, Walker SV, Behnke M, Dinkelacker AG, Eisenbeis S, Gastmeier P, Gölz H, Käding N, Kern WV, Kola A, Kramme E, Lucassen K, Mischnik A, Peter S, Rohde AM, Rupp J, Tacconelli E, Tobys D, Vehreschild MJGT, Wille J, Seifert H, Higgins PG. Surveillance and Genomic Analysis of Third-Generation Cephalosporin-Resistant and Carbapenem-Resistant Klebsiella pneumoniae Complex in Germany. Antibiotics (Basel) 2022; 11:antibiotics11101286. [PMID: 36289942 PMCID: PMC9598256 DOI: 10.3390/antibiotics11101286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
To analyse the epidemiology and population structure of third-generation cephalosporin-resistant (3GCR) and carbapenem-resistant (CR) Klebsiella pneumoniae complex isolates, patients were screened for rectal colonisation with 3GCR/CR K. pneumoniae complex on admission to six German university hospitals (2016–2019). Also collected were 3GCR/CR and susceptible K. pneumoniae isolates from patients with bloodstream infections (2016–2018). Whole-genome sequencing was performed followed by multilocus sequencing typing (MLST), core-genome MLST, and resistome and virulome analysis. The admission prevalence of 3GCR K. pneumoniae complex isolates during the 4-year study period was 0.8%, and 1.0 bloodstream infection per 1000 patient admissions was caused by K. pneumoniae complex (3GCR prevalence, 15.1%). A total of seven K. pneumoniae complex bloodstream isolates were CR (0.8%). The majority of colonising and bloodstream 3GCR isolates were identified as K. pneumoniae, 96.7% and 98.8%, respectively; the remainder were K. variicola and K. quasipneumoniae. cgMLST showed a polyclonal population of colonising and bloodstream isolates, which was also reflected by MLST and virulome analysis. CTX-M-15 was the most prevalent extended-spectrum beta-lactamase, and 29.7% of the colonising and 48.8% of the bloodstream isolates were high-risk clones. The present study provides an insight into the polyclonal 3GCR K. pneumoniae population in German hospitals.
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Nemec A, Radolfová-Křížová L, Maixnerová M, Shestivska V, Španělová P, Higgins PG. Corrigendum: Acinetobacter silvestris sp. nov. discovered in forest ecosystems in Czechia. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Singkham-In U, Higgins PG, Wannigama DL, Hongsing P, Chatsuwan T. Correction: Rescued chlorhexidine activity by resveratrol against carbapenem-resistant Acinetobacter baumannii via down-regulation of AdeB efflux pump. PLoS One 2022; 17:e0272881. [PMID: 35925988 PMCID: PMC9351991 DOI: 10.1371/journal.pone.0272881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Fuchs F, Becerra-Aparicio F, Xanthopoulou K, Seifert H, Higgins PG. In vitro activity of nitroxoline against carbapenem-resistant Acinetobacter baumannii isolated from the urinary tract. J Antimicrob Chemother 2022; 77:1912-1915. [PMID: 35411393 DOI: 10.1093/jac/dkac123] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/21/2022] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The old antimicrobial nitroxoline is currently repurposed for oral treatment of uncomplicated urinary tract infections (UTIs). OBJECTIVES To investigate the in vitro activity of nitroxoline against carbapenem-resistant Acinetobacter baumannii (CRAb). METHODS From an international collection of previously well-characterized clinical A. baumannii isolates, 34 isolates from urinary tract sources with different carbapenem-resistance mechanisms were selected. Nitroxoline activity was analysed with broth microdilution (BMD), disc diffusion (DD) and within an in vitro biofilm model. MICs of meropenem and imipenem were assessed with BMD. Susceptibility to ciprofloxacin and trimethoprim/sulfamethoxazole was investigated using DD. Escherichia coli ATCC 25922 and A. baumannii NCTC 13304 were used for quality control. RESULTS All isolates were carbapenem resistant (MIC90 >32 mg/L for meropenem and imipenem) and most isolates were resistant to ciprofloxacin (33/34) and trimethoprim/sulfamethoxazole (31/34). Nitroxoline yielded MIC50/90 values of 2/2 mg/L (MIC range 1-2 mg/L) and inhibition zone diameters ranging from 20 to 26 mm. In contrast, for definite eradication of biofilm-associated CRAb in vitro, higher nitroxoline concentrations (≥16 to ≥128 mg/L) were necessary for all isolates. CONCLUSIONS Nitroxoline showed excellent in vitro activity against a collection of CRAb despite high resistance rates to other antimicrobials for parental and oral therapy of A. baumannii UTI. Currently, nitroxoline is recommended for the treatment of uncomplicated UTI in Germany with a EUCAST breakpoint limited to uncomplicated UTI and E. coli (S ≤16 mg/L). Nitroxoline could be a promising drug for oral treatment of lower UTI caused by CRAb. More data are warranted to correlate these findings with in vivo success rates.
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Nemec A, Radolfová-Křížová L, Maixnerová M, Shestivska V, Španělová P, Higgins PG. Acinetobacter silvestris sp. nov. discovered in forest ecosystems in Czechia. Int J Syst Evol Microbiol 2022; 72. [PMID: 35439112 DOI: 10.1099/ijsem.0.005383] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We investigated a taxonomically novel group of the genus
Acinetobacter
, which included five strains isolated from soil and water samples collected in preserved forest areas in Czechia between 2013 and 2021. The whole-genome sequences of the strains were 3.1–3.2 Mb in size, with G+C contents of 38.0–38.2 mol%. Core genome-based phylogenetic analysis showed that they formed a compact and deeply branched clade within the genus. The genomic average nucleotide identity based on blast/digital DNA–DNA hybridization values for the novel strains were 99.2–99.6 %/95.2–98.4 %, whereas those between the novel strains and the type strains of the known
Acinetobacter
species reached <78 %/<24 %. The results of the genus-wide analysis of whole-cell MALDI-TOF mass spectra supported the sharp distinctness of the group. The five strains were non-glucose acidifying, nonhaemolytic, nonproteolytic and growing at 28 °C, but not at 32 °C; they assimilated acetate, benzoate, ethanol, l-histidine, 4-hydroxybenzoate, dl-lactate and malonate but not 4-aminobutyrate, l-aspartate or 2,3-butanediol; this phenotype is unique among the known
Acinetobacter
species. We conclude that the five strains represent a novel environmental species, for which the name Acinetobacter silvestris sp. nov. is proposed, with the type strain ANC 4999T (=CCM 9207T=CCUG 75877T=CNCTC 8124T).
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Biehl LM, Higgins PG, Stemler J, Gilles M, Peter S, Dörfel D, Vogel W, Kern WV, Gölz H, Bertz H, Rohde H, Klupp EM, Schafhausen P, Salmanton-García J, Stecher M, Wille J, Liss B, Xanthopoulou K, Zweigner J, Seifert H, Vehreschild MJGT. Impact of single-room contact precautions on acquisition and transmission of vancomycin-resistant enterococci on haematological and oncological wards, multicentre cohort-study, Germany, January-December 2016. Euro Surveill 2022; 27:2001876. [PMID: 35027104 PMCID: PMC8759111 DOI: 10.2807/1560-7917.es.2022.27.2.2001876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 08/18/2021] [Indexed: 06/14/2023] Open
Abstract
BackgroundEvidence supporting the effectiveness of single-room contact precautions (SCP) in preventing in-hospital acquisition of vancomycin-resistant enterococci (haVRE) is limited.AimWe assessed the impact of SCP on haVRE and their transmission.MethodsWe conducted a prospective, multicentre cohort study in German haematological/oncological departments during 2016. Two sites performed SCP for VRE patients and two did not (NCP). We defined a 5% haVRE-risk difference as non-inferiority margin, screened patients for VRE, and characterised isolates by whole genome sequencing and core genome MLST (cgMLST). Potential confounders were assessed by competing risk regression analysis.ResultsWe included 1,397 patients at NCP and 1,531 patients at SCP sites. Not performing SCP was associated with a significantly higher proportion of haVRE; 12.2% (170/1,397) patients at NCP and 7.4% (113/1,531) patients at SCP sites (relative risk (RR) 1.74; 95% confidence interval (CI): 1.35-2.23). The difference (4.8%) was below the non-inferiority margin. Competing risk regression analysis indicated a stronger impact of antimicrobial exposure (subdistribution hazard ratio (SHR) 7.46; 95% CI: 4.59-12.12) and underlying disease (SHR for acute leukaemia 2.34; 95% CI: 1.46-3.75) on haVRE than NCP (SHR 1.60; 95% CI: 1.14-2.25). Based on cgMLST and patient movement data, we observed 131 patient-to-patient VRE transmissions at NCP and 85 at SCP sites (RR 1.76; 95% CI: 1.33-2.34).ConclusionsWe show a positive impact of SCP on haVRE in a high-risk population, although the observed difference was below the pre-specified non-inferiority margin. Importantly, other factors including antimicrobial exposure seem to be more influential.
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Wendel AF, Malecki M, Mattner F, Xanthopoulou K, Wille J, Seifert H, Higgins PG. OUP accepted manuscript. JAC Antimicrob Resist 2022; 4:dlac057. [PMID: 35611260 PMCID: PMC9122648 DOI: 10.1093/jacamr/dlac057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/03/2022] [Indexed: 11/24/2022] Open
Abstract
Objectives To describe the propensity of carbapenem-resistant Pseudomonas aeruginosa to spread within a hospital critical care setting. Methods The study was conducted in a 700-bed tertiary centre in Cologne, Germany. P. aeruginosa resistant to piperacillin, ceftazidime, cefepime, imipenem, meropenem and ciprofloxacin, isolated from clinical and screening specimens from four critical care units from 2015 to 2020 were analysed. Genotyping was carried out by WGS (Illumina and MinION). MLST, core genome MLST (cgMLST) and resistome analysis was performed and merged with epidemiological data. Results Fifty-five out of 79 non-duplicate P. aeruginosa isolates were available, of which 20 were carbapenemase producers as follows: blaVIM-1 (n = 1), blaVIM-2 (n = 17), blaVIM-4 (n = 1), and blaNDM-1/blaGES-5 (n = 1). Forty-two of 55 isolates were hospital-acquired. cgMLST revealed three clusters: Cluster 1 (n = 15, ST111, blaVIM-2, recovered between 2015 and 2020); Cluster 2 (n = 4, ST970, carbapenemase negative); and Cluster 3 (n = 2, ST357, carbapenemase negative). The blaVIM-2 gene of Cluster 1 was integrated on the chromosome in a class 1 integron (type In59). Using conventional epidemiology, we were only able to confirm two patient-to-patient transmissions and one room-to-patient transmission on three different ICUs within Cluster 1. Isolates from Cluster 2 represented an outbreak occurring in 2019. Conclusions These data give insight into the epidemiology of carbapenem-resistant P. aeruginosa. Transmission dynamics differed between carbapenemase- and non-carbapenemase-producing isolates. A continuous acquisition of clonally related ST111 VIM-2 P. aeruginosa, being the main carbapenemase-producing strain, was observed over the whole study period, as well as an overall higher genomic diversity among non-carbapenemase-producing P. aeruginosa.
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Wannigama DL, Higgins PG, Hurst C, Abe S, Hongsing P, Luk-In S, Kueakulpattana N, Laowansiri M, Tanasatitchai C, Srisakul S, Kicic A, Chatsuwan T, Moussa S, Miller A. 1073. Sulbactam-Durlobactam Has Potent Activity Against Multidrug-Resistant Acinetobacter baumannii Clinical Isolates From Thai Patients With Chronic Infections. Open Forum Infect Dis 2021. [DOI: 10.1093/ofid/ofab466.1267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Due to the increase in multi-drug resistance (MDR) of Acinetobacter baumannii chronic infections with accompanying considerable morbidity and mortality, it is imperative to find effective novel treatments. Durlobactam (DUR) is a potent broad-spectrum inhibitor of Ambler classes A, C and D serine β-lactamases that effectively restores sulbactam (SUL) activity against MDR A.baumannii isolates. SUL-DUR is currently in late-stage development for the treatment of infections caused by Acinetobacter spp., including drug resistant isolates. In this study, we sought to evaluate potency of SUL-DUR against MDR A. baumannii isolates collected from Thai patients with chronic infections.
Methods
Non-duplicative clinical strains were isolated during 2016–2019 from 200 chronically infected patients in different medical wards with a variety of different infections at King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Susceptibility testing of SUL-DUR and comparator agents was performed according to CLSI guidelines. SUL-DUR was also tested on a background of imipenem (IPM) therapy (SUL-IPM titrated at a 1:1 ratio plus DUR fixed at 4 mg/L). Data analysis was performed using CLSI and EUCAST breakpoint criteria where available.
Results
This collection of isolates was 92% sulbactam-resistant (using a breakpoint of 4 mg/L), 91% carbapenem-resistant, 74% amikacin resistant and 8% colistin resistant. In contrast, the SUL-DUR MIC90 was 4 mg/L compared with 64 mg/L for sulbactam alone. SUL-DUR was equally potent across antibiotic-resistant subsets. Only 6 isolates (3%) had SUL-DUR MIC values >4 mg/L. Interestingly, addition of imipenem to SUL-DUR showed similar potency as SUL-DUR alone, with an MIC90 of 2 mg/L.
Conclusion
SUL-DUR showed potent in vitro activity against contemporary clinical isolates from a hospital in Bangkok, Thailand. If successfully developed, SUL-DUR may be an important new therapeutic option for the treatment of MDR Acinetobacter infections.
Disclosures
Alita Miller, PhD, Entasis Therapeutics (Employee)
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Wannigama DL, Kueakulpattana N, Luk-In S, Hongsing P, Hurst C, Badavath VN, Jenjaroenpun P, Wongsurawat T, Teeratakulpisan N, Kerr SJ, Abe S, Pearson L, Saethang T, Chantaravisoot N, Higgins PG, Chatsuwan T. 1355. Cluster of Multi-drug Resistance Neisseria gonorrhoeae Isolates with Reduce Ceftriaxone Susceptibility, First Report in Thailand. Open Forum Infect Dis 2021. [DOI: 10.1093/ofid/ofab466.1547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Rapid emergence of global azithromycin resistance, with ceftriaxone reduce susceptibility/resistant strains, threatens the current recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment. Thailand is a major risk area for gonorrhea because it as a key destination for sex tourism industry, where antibiotic resistance gonorrhea can spread easily and quickly across the region. Here, we identified a first cluster of Neisseria gonorrhoeae isolates with decreased ceftriaxone susceptibility in Thailand.
Methods
A 134 N. gonorrhoeae isolates collected from Thai Red Cross Anonymous Clinic, Bangkok, during 2016–2018 were studied. Broth micro-dilution and plate dilution methods to define resistance or decreased susceptibilityaccording to CLSI guidelines. Select isolates were subjected to whole genome sequencing with an Illumina MiSeq V2 instrument and analysis using CLCBio Genomics Workbench v6.5. Molecular docking studies were carried out to understand binding mode analysis and orientation of ceftriaxone in the active site of PBP2. Biofilm formation measured by confocal laser scanning microscopy.
Results
Among the N. gonorrhoeae clinical isolates, two isolates had significant reduced susceptibility to ceftriaxone (MICs of 0.125 mg/L), which were isolated from urethral swab in male heterosexual patients. Both were multidrug resistance and strong biofilm producers with ceftriaxone tolerance (MBEC > 128 mg/L). One isolate was resistant to azithromycin (MIC of 1 mg/L), and other one remained susceptible (MIC of 0.5 mg/L). Reduced susceptibility to ceftriaxone associated with alterations in PBP2, PBP1, PorB, MtrR, and mtrR promoter region with one belonged to ST7235 and second one had new allele number of tbpB with new sequence type (ST). Ceftriaxone weakly occupy the active site of mosaic XXXIV penicillin-binding protein 2 (PBP2) variant in both. Molecular epidemiology results reviled that both isolates display similarities with isolates from UK, USA, and Netherlands.
Conclusion
This first cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility may bring threat of treatment failure in Thailand. Also highlighted the importance of maintaining surveillance for antimicrobial resistance.
Disclosures
All Authors: No reported disclosures
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Mouftah SF, Pál T, Higgins PG, Ghazawi A, Idaghdour Y, Alqahtani M, Omrani AS, Rizvi TA, Sonnevend Á. Diversity of carbapenem-resistant Klebsiella pneumoniae ST14 and emergence of a subgroup with KL64 capsular locus in the Arabian Peninsula. Eur J Clin Microbiol Infect Dis 2021:10.1007/s10096-021-04384-2. [PMID: 34855011 DOI: 10.1007/s10096-021-04384-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
To understand the reasons of successful spread of carbapenem-resistant Klebsiella pneumoniae ST14 (CRKP-ST14) in countries of the Arabian Peninsula, the resistome, capsular locus, carbapenemase carrying plasmid types, and core genome of isolates from the region were compared to global isolates. Thirty-nine CRKP-ST14 strains isolated from 13 hospitals in the United Arab Emirates, Bahrain, and Saudi Arabia were selected for whole genome sequencing on Illumina MiSeq platform based on the variety of carbapenemase genes carried and plasmids bearing these genes. Their resistome, capsular locus, and core genome MLST were compared to 173 CRKP-ST14 genomes available in public databases. The selected 39 CRKP-ST14 produced either NDM-1, OXA-48, OXA-162, OXA-232, KPC-2, or co-produced NDM-1 and an OXA-48-like carbapenemase. cgMLST revealed three clusters: 16 isolates from five UAE cities (C1), 11 isolates from three UAE cities and Bahrain (C2), and 5 isolates from Saudi Arabia (C3), respectively, and seven singletons. Resistance gene profile, carbapenemase genes, and their plasmid types were variable in both C1 and C2 clusters. The majority of CRKP-ST14 had KL2, but members of the C2 cluster and two further singletons possessed KL64 capsular locus. Based on cgMLST comparison of regional and global isolates, CRKP-ST14 with KL64 from four continents formed a distinct cluster, suggesting a recent emergence and spread of this variant. Our findings confirmed clonal transmission coupled with likely horizontal gene transfer in carbapenem-resistant Klebsiella pneumoniae ST14. Dissemination of this genetically flexible, highly resistant clone warrants further monitoring.
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Pournaras S, Zarrilli R, Higgins PG, Tsioutis C. Editorial: Carbapenemase-Producing Organisms as Leading Cause of Hospital Infections. Front Med (Lausanne) 2021; 8:775021. [PMID: 34760905 PMCID: PMC8572846 DOI: 10.3389/fmed.2021.775021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022] Open
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Shein AMS, Wannigama DL, Higgins PG, Hurst C, Abe S, Hongsing P, Chantaravisoot N, Saethang T, Luk-in S, Liao T, Nilgate S, Rirerm U, Kueakulpattana N, Laowansiri M, Srisakul S, Muhummudaree N, Techawiwattanaboon T, Gan L, Xu C, Kupwiwat R, Phattharapornjaroen P, Rojanathanes R, Leelahavanichkul A, Chatsuwan T. Novel colistin-EDTA combination for successful eradication of colistin-resistant Klebsiella pneumoniae catheter-related biofilm infections. Sci Rep 2021; 11:21676. [PMID: 34737361 PMCID: PMC8568960 DOI: 10.1038/s41598-021-01052-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/20/2021] [Indexed: 12/20/2022] Open
Abstract
Development of an effective therapy to overcome colistin resistance in Klebsiella pneumoniae, a common pathogen causing catheter-related biofilm infections in vascular catheters, has become a serious therapeutic challenge that must be addressed urgently. Although colistin and EDTA have successful roles for eradicating biofilms, no in vitro and in vivo studies have investigated their efficacy in catheter-related biofilm infections of colistin-resistant K. pneumoniae. In this study, colistin resistance was significantly reversed in both planktonic and mature biofilms of colistin-resistant K. pneumoniae by a combination of colistin (0.25-1 µg/ml) with EDTA (12 mg/ml). This novel colistin-EDTA combination was also demonstrated to have potent efficacy in eradicating colistin-resistant K. pneumoniae catheter-related biofilm infections, and eliminating the risk of recurrence in vivo. Furthermore, this study revealed significant therapeutic efficacy of colistin-EDTA combination in reducing bacterial load in internal organs, lowering serum creatinine, and protecting treated mice from mortality. Altered in vivo expression of different virulence genes indicate bacterial adaptive responses to survive in hostile environments under different treatments. According to these data discovered in this study, a novel colistin-EDTA combination provides favorable efficacy and safety for successful eradication of colistin-resistant K. pneumonia catheter-related biofilm infections.
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Kueakulpattana N, Wannigama DL, Luk-In S, Hongsing P, Hurst C, Badavath VN, Jenjaroenpun P, Wongsurawat T, Teeratakulpisan N, Kerr SJ, Abe S, Phattharapornjaroen P, Shein AMS, Saethang T, Chantaravisoot N, Amarasiri M, Higgins PG, Chatsuwan T. Multidrug-resistant Neisseria gonorrhoeae infection in heterosexual men with reduced susceptibility to ceftriaxone, first report in Thailand. Sci Rep 2021; 11:21659. [PMID: 34737332 PMCID: PMC8569152 DOI: 10.1038/s41598-021-00675-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/15/2021] [Indexed: 12/01/2022] Open
Abstract
The global rapid emergence of azithromycin/ceftriaxone resistant Neisseria gonorrhoeae threatens current recommend azithromycin/ceftriaxone dual therapy for gonorrhea to ensure effective treatment. Here, we identified the first two N. gonorrhoeae isolates with decreased ceftriaxone susceptibility in Thailand. Among 134 N. gonorrhoeae isolates collected from Thai Red Cross Anonymous Clinic, Bangkok, two isolates (NG-083 and NG-091) from urethral swab in male heterosexual patients had reduced susceptibility to ceftriaxone (MICs of 0.125 mg/L). Both were multidrug resistant and strong biofilm producers with ceftriaxone tolerance (MBEC > 128 mg/L). NG-083 and NG-091 remained susceptible to azithromycin (MIC of 1 mg/L and 0.5 mg/L, respectively). Reduced susceptibility to ceftriaxone was associated with alterations in PBP2, PBP1, PorB, MtrR, and mtrR promoter region. NG-083 belonged to sequence type (ST) 7235 and NG-091 has new allele number of tbpB with new ST. Molecular docking revealed ceftriaxone weakly occupied the active site of mosaic XXXIV penicillin-binding protein 2 variant in both isolates. Molecular epidemiology results revealed that both isolates display similarities with isolates from UK, USA, and The Netherlands. These first two genetically related gonococcal isolates with decreased ceftriaxone susceptibility heralds the threat of treatment failure in Thailand, and importance of careful surveillance.
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Higgins PG, Kniel M, Rojak S, Balczun C, Rohde H, Frickmann H, Hagen RM. Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Strains Isolated at the German Military Field Laboratory in Mazar-e Sharif, Afghanistan. Microorganisms 2021; 9:microorganisms9112229. [PMID: 34835355 PMCID: PMC8622437 DOI: 10.3390/microorganisms9112229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 10/22/2021] [Accepted: 10/22/2021] [Indexed: 11/20/2022] Open
Abstract
The study was performed to provide an overview of the molecular epidemiology of carbapenem-resistant Acinetobacter baumannii in Afghanistan isolated by the German military medical service during the Afghanistan conflict. A total of 18 isolates were collected between 2012 and 2018 at the microbiological laboratory of the field hospital in Camp Marmal near Mazar-e Sharif, Afghanistan, from Afghan patients. The isolates were subjected to phenotypic and genotypic differentiation and antimicrobial susceptibility testing as well as to a core genome multi-locus sequence typing (cgMLST) approach based on whole-genome next-generation sequence (wgNGS) data. Next to several sporadic isolates, four transmission clusters comprising strains from the international clonal lineages IC1, IC2, and IC9 were identified. Acquired carbapenem resistance was due to blaOXA-23 in 17/18 isolates, while genes mediating resistance against sulfonamides, macrolides, tetracyclines, and aminoglycosides were frequently identified as well. In conclusion, the assessment confirmed both the frequent occurrence of A. baumannii associated with outbreak events and a variety of different clones in Afghanistan. The fact that acquired carbapenem resistance was almost exclusively associated with blaOXA-23 may facilitate molecular resistance screening based on rapid molecular assays targeting this resistance determinant.
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Shein AMS, Wannigama DL, Higgins PG, Leelahavanichkul A, Chatsuwan T. Colistin-EDTA combination for eradication of colistin-resistant Klebsiella pneumoniae catheter related biofilm infections. Int J Antimicrob Agents 2021. [DOI: 10.1016/j.ijantimicag.2021.106421.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Paul G, Meißner A, Neuneier J, Neuschmelting V, Grau S, Yagdiran A, Scheyerer MJ, Malin JJ, Suárez I, Lehmann C, Exner M, Wiesmüller GA, Higgins PG, Seifert H, Fätkenheuer G, Zweigner J, Jung N. Outbreak of Pseudomonas aeruginosa infections after CT-guided spinal injections. J Hosp Infect 2021; 116:1-9. [PMID: 34298033 DOI: 10.1016/j.jhin.2021.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Meningitis and spinal infections with Gram-negative bacteria after local injections for treatment of chronic back pain are rare. This study investigated an outbreak of Pseudomonas aeruginosa infections following computed tomography (CT)-guided spinal injections (SI). METHODS A case was defined as a spinal infection or meningitis with P. aeruginosa after SI between 10th January and 1st March 2019 in the same outpatient clinic. Patients without microbiological evidence of P. aeruginosa but with a favourable response to antimicrobial therapy active against P. aeruginosa were defined as probable cases. FINDINGS Twenty-eight of 297 patients receiving CT-guided SI during the study period developed meningitis or spinal infections. Medical records were available for 19 patients. In 15 patients, there was microbiological evidence of P. aeruginosa, and four patients were defined as probable cases. Two of 19 patients developed meningitis, while the remaining 17 patients developed spinal infections. The median time from SI to hospital admission was 8 days (interquartile range 2-23 days). Patients mainly presented with back pain (N=18; 95%), and rarely developed fever (N=3; 16%). Most patients required surgery (N=16; 84%). Seven patients (37%) relapsed and one patient died. Although the source of infection was not identified microbiologically, documented failures in asepsis when performing SI probably contributed to these infections. CONCLUSIONS SI is generally considered safe, but non-adherence to asepsis can lead to deleterious effects. Spinal infections caused by P. aeruginosa are difficult to treat and have a high relapse rate.
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Hua X, He J, Wang J, Zhang L, Zhang L, Xu Q, Shi K, Leptihn S, Shi Y, Fu X, Zhu P, Higgins PG, Yu Y. Novel tigecycline resistance mechanisms in Acinetobacter baumannii mediated by mutations in adeS, rpoB and rrf. Emerg Microbes Infect 2021; 10:1404-1417. [PMID: 34170209 PMCID: PMC8274536 DOI: 10.1080/22221751.2021.1948804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Acinetobacter baumannii is an important pathogen in hospital acquired infections. Although tigecycline currently remains a potent antibiotic for treating infections caused by multidrug resistant A. baumannii (MDRAB) strains, reports of tigecycline resistant isolates have substantially increased. The resistance mechanisms to tigecycline in A. baumannii are far more complicated and diverse than what has been described in the literature so far. Here, we characterize in vitro-selected MDRAB strains obtained by increasing concentrations of tigecycline. We have identified mutations in adeS, rrf and rpoB that result in reduced susceptibility to tigecycline. Using in situ complementation experiments, we confirm that mutations in rrf, rpoB, and two types of mutations in adeS correlate with tigecycline resistance. By Western blot and polysome profile analysis, we demonstrate that the rrf mutation results in decreased expression of RRF, which affects the process of ribosome recycling ultimately leading to increased tigecycline tolerance. A transcriptional analysis shows that the mutated rpoB gene plays a role in regulating the expression of the SAM-dependent methyltransferase (trm) and transcriptional regulators, to confer moderate tigecycline resistance. This study provides direct in vitro evidence that mutations in the adeS, rpoB and rrf are associated with tigecycline resistance in A. baumannii.
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Lucaßen K, Müller C, Wille J, Xanthopoulou K, Hackel M, Seifert H, Higgins PG. Prevalence of RND efflux pump regulator variants associated with tigecycline resistance in carbapenem-resistant Acinetobacter baumannii from a worldwide survey. J Antimicrob Chemother 2021; 76:1724-1730. [PMID: 33760099 DOI: 10.1093/jac/dkab079] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/18/2021] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To determine the most common tigecycline resistance mechanisms in carbapenem-resistant Acinetobacter baumannii isolates obtained during the global Tigecycline Evaluation Surveillance Trial (TEST). METHODS Tigecycline MICs were determined by broth microdilution. WGS was used to screen for the previously identified tigecycline resistance mechanisms, as well as mutations in resistance-nodulation-cell division (RND)-type efflux pump regulators. RESULTS From a total 313 isolates, 113 genetically unique tigecycline-resistant isolates were analysed. The most frequent and worldwide distributed mechanism associated with tigecycline resistance was disruption of adeN, which encodes the repressor of the RND efflux pump AdeIJK, either by IS elements or nucleotide deletions causing premature stop codons. However, mutations leading to amino acid substitutions and disruption by IS elements within the two-component regulatory system adeRS, which regulates expression of the AdeABC efflux pump, correlate with higher tigecycline MICs, but these were found less frequently and were mainly restricted to Southern European countries. Furthermore, an altered version of tviB was identified in several tigecycline-resistant isolates that did not have putative resistance mutations within RND-type regulators. The resistance determinants tet(A) and tet(X), as well as resistance mutations in putative resistance determinants trm, plsC, rrf, msbA and genes encoding 30S ribosomal proteins, were not identified in any isolate. CONCLUSIONS The most prevalent tigecycline resistance mechanisms were caused by alterations in the regulators of RND-type efflux pumps. These data provide the basis for further characterization of regulator alterations and their contribution to increased efflux and tigecycline resistance, and also should be taken into account in drug discovery programmes to overcome the contribution of efflux pumps.
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Xanthopoulou K, Peter S, Tobys D, Behnke M, Dinkelacker AG, Eisenbeis S, Falgenhauer J, Falgenhauer L, Fritzenwanker M, Gölz H, Häcker G, Higgins PG, Imirzalioglu C, Käding N, Kern WV, Kramme E, Kola A, Mischnik A, Rieg S, Rohde AM, Rupp J, Tacconelli E, Vehreschild MJGT, Walker SV, Gastmeier P, Seifert H. Vancomycin-resistant Enterococcus faecium colonizing patients on hospital admission in Germany: prevalence and molecular epidemiology. J Antimicrob Chemother 2021; 75:2743-2751. [PMID: 32699884 DOI: 10.1093/jac/dkaa271] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES To analyse the rectal carriage rate and the molecular epidemiology of vancomycin-resistant Enterococcus faecium (VREfm) recovered from patients upon hospital admission. METHODS Adult patients were screened at six German university hospitals from five different federal states upon hospital admission for rectal colonization with VREfm between 2014 and 2018. Molecular characterization of VREfm was performed by WGS followed by MLST and core-genome MLST analysis. RESULTS Of 16350 patients recruited, 263 were colonized with VREfm, with increasing prevalence rates during the 5 year study period (from 0.8% to 2.6%). In total, 78.5% of the VREfm were vanB positive and 20.2% vanA positive, while 1.2% harboured both vanA and vanB. The predominant ST was ST117 (56.7%) followed by ST80 (15%), ST203 (10.9%), ST78 (5.7%) and ST17 (3.2%). ST117/vanB VREfm isolates formed a large cluster of 96 closely related isolates extending across all six study centres and four smaller clusters comprising 13, 5, 4 and 3 isolates each. In contrast, among the other STs inter-regional clonal relatedness was rarely observed. CONCLUSIONS To our knowledge, this is the largest admission prevalence and molecular epidemiology study of VREfm. These data provide insight into the epidemiology of VREfm at six German university hospitals and demonstrate the remarkable inter-regional clonal expansion of the ST117/vanB VREfm clone.
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Goeser F, Sifft B, Stein-Thoeringer C, Farowski F, Strassburg CP, Brossart P, Higgins PG, Scheid C, Wolf D, Holderried TAW, Vehreschild MJGT, Cruz Aguilar MR. Fecal microbiota transfer for refractory intestinal graft-versus-host disease - Experience from two German tertiary centers. Eur J Haematol 2021; 107:229-245. [PMID: 33934412 DOI: 10.1111/ejh.13642] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 12/17/2022]
Abstract
RATIONALE Steroid refractory graft-vs-host disease (sr-GvHD) represents a challenging complication after allogeneic hematopoietic cell transplantation (allo-HCT). Intestinal microbiota (IM) diversity and dysbiosis were identified as influencing factors for the development of acute GvHD. Fecal microbiota transfer (FMT) is hypothesized to restore IM dysbiosis, but there is limited knowledge about the significance of FMT in the treatment of sr-GvHD. OBJECTIVES We studied the effects of FMT on sr-GvHD in allo-HCT patients from two German tertiary clinical centers (n = 11 patients; period: March 2017 until July 2019). To assess safety and clinical efficacy, we analyzed clinical data pre- and post-FMT (day -14 to +30 relative to FMT). Moreover, IM were analyzed in donor samples and in a subset of patients pre- and post-FMT by 16S rRNA sequencing. RESULTS Post-FMT, we observed no intervention-associated, systemic inflammatory responses and only minor side effects (5/11 patients: abdominal pain and transformation of peristalsis-each 3/11 and vomiting-1/11). Stool frequencies and volumes were significantly reduced [pre- vs post-FMT (d14): P < .05, respectively] as well as clear attenuation regarding both grading and staging of sr-GvHD was present upon FMT. Moreover, IM analyses revealed an increase of alpha diversity as well as a compositional shifts toward the donor post-FMT. CONCLUSIONS In our study, we observed positive effects on sr-GVHD after FMT without the occurrence of major adverse events. Although these findings are in line with published data on beneficial effects of FMT in sr-GvHD, further randomized clinical studies are urgently needed to better define the clinical validity including mode of action.
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Nemec A, Radolfová-Křížová L, Maixnerová M, Nemec M, Španělová P, Šafránková R, Šedo O, Lopes BS, Higgins PG. Delineation of a novel environmental phylogroup of the genus Acinetobacter encompassing Acinetobacter terrae sp. nov., Acinetobacter terrestris sp. nov. and three other tentative species. Syst Appl Microbiol 2021; 44:126217. [PMID: 34107439 DOI: 10.1016/j.syapm.2021.126217] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/14/2021] [Accepted: 05/14/2021] [Indexed: 11/29/2022]
Abstract
This study aimed to define the taxonomic position and structure of a novel, taxonomically unique group of 26 Acinetobacter strains, provisionally designated Taxon 24 (T24). The strains were recovered from soil and freshwater ecosystems (n = 21) or animals (n = 5) in Czechia, Scotland, Germany, the Netherlands and Turkey between 1993 and 2015. They were non-glucose-acidifying, nonhemolytic, nonproteolytic, growing at 32 °C and on acetate and ethanol as single carbon sources, but not on 4-hydroxybenzoate and mostly not at 37 °C. Their whole-genome sequences were 3.0-3.7 Mb in size, with GC contents of 39.8-41.3%. Based on core genome phylogenetic analysis, the 26 strains formed a distinct clade within the genus Acinetobacter, with strongly supported subclades termed T24A (n = 11), T24B (n = 8), T24C (n = 2), T24D (n = 3) and T24E (n = 2). The internal genomic ANIb values for these subclades were >94.8%, while the ANIb values between them were <92.5%. The results of MALDI-TOF MS-based analyses agreed with this classification. The five subclades differed from each other in the results of one to six carbon source assimilation tests. Given the genomic and phenotypic distinctness, internal coherence, numbers of available strains and geographically diverse origin of T24A and T24B, we propose the names Acinetobacter terrae sp. nov. and Acinetobacter terrestris sp. nov. for these two taxa, respectively. The type strains are ANC 4282v (= CCM 8986T = CCUG 73811T = CNCTC 8082T) and ANC 4471T (= CCM 8985T = CCUG 73812T = CNCTC 8093T), respectively. We conclude that these two species together with the other T24 strains represent a widely dispersed Acinetobacter clade primarily associated with terrestrial ecosystems.
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