scholarly journals Comparative Whole-Genome Phylogeny of Animal, Environmental, and Human Strains Confirms the Genogroup Organization and Diversity of the Stenotrophomonas maltophilia Complex

2020 ◽  
Vol 86 (10) ◽  
Author(s):  
Mélanie Mercier-Darty ◽  
Guilhem Royer ◽  
Brigitte Lamy ◽  
Chadly Charron ◽  
Olivier Lemenand ◽  
...  

ABSTRACT The Stenotrophomonas maltophilia complex (Smc) comprises opportunistic environmental Gram-negative bacilli responsible for a variety of infections in both humans and animals. Beyond its large genetic diversity, its genetic organization in genogroups was recently confirmed through the whole-genome sequencing of human and environmental strains. As they are poorly represented in these analyses, we sequenced the whole genomes of 93 animal strains to determine their genetic background and characteristics. Combining these data with 81 newly sequenced human strains and the genomes available from RefSeq, we performed a genomic analysis that included 375 nonduplicated genomes with various origins (animal, 104; human, 226; environment, 30; unknown, 15). Phylogenetic analysis and clustering based on genome-wide average nucleotide identity confirmed and specified the genetic organization of Smc in at least 20 genogroups. Two new genogroups were identified, and two previously described groups were further divided into two subgroups each. Comparing the strains isolated from different host types and their genogroup affiliation, we observed a clear disequilibrium in certain groups. Surprisingly, some antimicrobial resistance genes, integrons, and/or clusters of attC sites lacking integron-integrase (CALIN) sequences targeting antimicrobial compounds extensively used in animals were mainly identified in animal strains. We also identified genes commonly found in animal strains coding for efflux systems. The result of a large whole-genome analysis performed by us supports the hypothesis of the putative contribution of animals as a reservoir of Stenotrophomonas maltophilia complex strains and/or resistance genes for strains in humans. IMPORTANCE Given its naturally large antimicrobial resistance profile, the Stenotrophomonas maltophilia complex (Smc) is a set of emerging pathogens of immunosuppressed and cystic fibrosis patients. As it is group of environmental microorganisms, this adaptation to humans is an opportunity to understand the genetic and metabolic selective mechanisms involved in this process. The previously reported genomic organization was incomplete, as data from animal strains were underrepresented. We added the missing piece of the puzzle with whole-genome sequencing of 93 strains of animal origin. Beyond describing the phylogenetic organization, we confirmed the genetic diversity of the Smc, which could not be estimated through routine phenotype- or matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF)-based laboratory tests. Animals strains seem to play a key role in the diversity of Smc and could act as a reservoir for mobile resistance genes. Some genogroups seem to be associated with particular hosts; the genetic support of this association and the role of the determinants/corresponding genes need to be explored.

2016 ◽  
Vol 60 (9) ◽  
pp. 5515-5520 ◽  
Author(s):  
Patrick F. McDermott ◽  
Gregory H. Tyson ◽  
Claudine Kabera ◽  
Yuansha Chen ◽  
Cong Li ◽  
...  

ABSTRACTLaboratory-basedin vitroantimicrobial susceptibility testing is the foundation for guiding anti-infective therapy and monitoring antimicrobial resistance trends. We used whole-genome sequencing (WGS) technology to identify known antimicrobial resistance determinants among strains of nontyphoidalSalmonellaand correlated these with susceptibility phenotypes to evaluate the utility of WGS for antimicrobial resistance surveillance. Six hundred fortySalmonellaof 43 different serotypes were selected from among retail meat and human clinical isolates that were tested for susceptibility to 14 antimicrobials using broth microdilution. The MIC for each drug was used to categorize isolates as susceptible or resistant based on Clinical and Laboratory Standards Institute clinical breakpoints or National Antimicrobial Resistance Monitoring System (NARMS) consensus interpretive criteria. Each isolate was subjected to whole-genome shotgun sequencing, and resistance genes were identified from assembled sequences. A total of 65 unique resistance genes, plus mutations in two structural resistance loci, were identified. There were more unique resistance genes (n =59) in the 104 human isolates than in the 536 retail meat isolates (n =36). Overall, resistance genotypes and phenotypes correlated in 99.0% of cases. Correlations approached 100% for most classes of antibiotics but were lower for aminoglycosides and beta-lactams. We report the first finding of extended-spectrum β-lactamases (ESBLs) (blaCTX-M1andblaSHV2a) in retail meat isolates ofSalmonellain the United States. Whole-genome sequencing is an effective tool for predicting antibiotic resistance in nontyphoidalSalmonella, although the use of more appropriate surveillance breakpoints and increased knowledge of new resistance alleles will further improve correlations.


2015 ◽  
Vol 82 (2) ◽  
pp. 459-466 ◽  
Author(s):  
S. Zhao ◽  
G. H. Tyson ◽  
Y. Chen ◽  
C. Li ◽  
S. Mukherjee ◽  
...  

ABSTRACTThe objectives of this study were to identify antimicrobial resistance genotypes forCampylobacterand to evaluate the correlation between resistance phenotypes and genotypes usingin vitroantimicrobial susceptibility testing and whole-genome sequencing (WGS). A total of 114Campylobacterspecies isolates (82C. coliand 32C. jejuni) obtained from 2000 to 2013 from humans, retail meats, and cecal samples from food production animals in the United States as part of the National Antimicrobial Resistance Monitoring System were selected for study. Resistance phenotypes were determined using broth microdilution of nine antimicrobials. Genomic DNA was sequenced using the Illumina MiSeq platform, and resistance genotypes were identified using assembled WGS sequences through blastx analysis. Eighteen resistance genes, includingtet(O),blaOXA-61,catA,lnu(C),aph(2″)-Ib,aph(2″)-Ic,aph(2′)-If,aph(2″)-Ig,aph(2″)-Ih,aac(6′)-Ie-aph(2″)-Ia,aac(6′)-Ie-aph(2″)-If,aac(6′)-Im,aadE,sat4,ant(6′),aad9,aph(3′)-Ic, andaph(3′)-IIIa, and mutations in two housekeeping genes (gyrAand 23S rRNA) were identified. There was a high degree of correlation between phenotypic resistance to a given drug and the presence of one or more corresponding resistance genes. Phenotypic and genotypic correlation was 100% for tetracycline, ciprofloxacin/nalidixic acid, and erythromycin, and correlations ranged from 95.4% to 98.7% for gentamicin, azithromycin, clindamycin, and telithromycin. All isolates were susceptible to florfenicol, and no genes associated with florfenicol resistance were detected. There was a strong correlation (99.2%) between resistance genotypes and phenotypes, suggesting that WGS is a reliable indicator of resistance to the nine antimicrobial agents assayed in this study. WGS has the potential to be a powerful tool for antimicrobial resistance surveillance programs.


2018 ◽  
Vol 84 (13) ◽  
pp. e02829-17 ◽  
Author(s):  
I. M. Leon ◽  
S. D. Lawhon ◽  
K. N. Norman ◽  
D. S. Threadgill ◽  
N. Ohta ◽  
...  

ABSTRACTAlthoughSalmonella entericacan produce life-threatening colitis in horses, certain serotypes are more commonly associated with clinical disease. Our aim was to evaluate the proportional morbidity attributed to different serotypes, as well as the phenotypic and genotypic antimicrobial resistance (AMR) ofSalmonellaisolates from patients at an equine referral hospital in the southern United States. A total of 255Salmonellaisolates was obtained from clinical samples of patients admitted to the hospital between 2007 and 2015. Phenotypic resistance to 14 antibiotics surveilled by the U.S. National Antimicrobial Resistance Monitoring System was determined using a commercially available panel. Whole-genome sequencing was used to identify serotypes and genotypic AMR. The most common serotypes wereSalmonella entericaserotype Newport (18%),Salmonella entericaserotype Anatum (15.2%), andSalmonella entericaserotype Braenderup (11.8%). Most (n= 219) of the isolates were pansusceptible, while 25 were multidrug resistant (≥3 antimicrobial classes). Genes encoding beta-lactam resistance, such asblaCMY-2,blaSHV-12,blaCTX-M-27, andblaTEM-1B, were detected. TheqnrB2 andaac(6′)-Ib-crgenes were present in isolates with reduced susceptibility to ciprofloxacin. Genes encoding resistance to gentamicin (aph(3′)-Ia,aac(6′)-IIc), streptomycin (strA andstrB), sulfonamides (sul1), trimethoprim (dfrA), phenicols (catA), tetracyclines [tet(A) andtet(E)], and macrolides [ere(A)] were also identified. The main predicted incompatibility plasmid type was I1 (10%). Core genome-based analyses revealed phylogenetic associations between isolates of common serotypes. The presence of AMRSalmonellain equine patients increases the risk of unsuccessful treatment and causes concern for potential zoonotic transmission to attending veterinary personnel, animal caretakers, and horse owners. Understanding the epidemiology ofSalmonellain horses admitted to referral hospitals is important for the prevention, control, and treatment of salmonellosis.IMPORTANCEIn horses, salmonellosis is a leading cause of life-threatening colitis. At veterinary teaching hospitals, nosocomial outbreaks can increase the risk of zoonotic transmission, lead to restrictions on admissions, impact hospital reputation, and interrupt educational activities. The antimicrobials most often used in horses are included in the 5th revision of the World Health Organization's list of critically important antimicrobials for human medicine. Recent studies have demonstrated a trend of increasing bacterial resistance to drugs commonly used to treatSalmonellainfections. In this study, we identify temporal trends in the distribution ofSalmonellaserotypes and their mechanisms of antimicrobial resistance; furthermore, we are able to determine the likely origin of several temporal clusters of infection by using whole-genome sequencing. These data can be used to focus strategies to better contain the dissemination and enhance the mitigation ofSalmonellainfections and to provide evidence-based policies and guidelines to steward antimicrobial use in veterinary medicine.


Author(s):  
Justine Schaeffer ◽  
Steliana Huhulescu ◽  
Anna Stoeger ◽  
Franz Allerberger ◽  
Werner Ruppitsch

Background: Diphtheria is a vaccine preventable disease with a high potential for re-emergence. One of its causative agent is Corynebacterium diphtheriae, some strains producing the diphtheria toxin. From 2011 to 2019, 57 clinical C. diphtheriae strains were isolated in Austria, either from the respiratory track or from skin infections. Objectives: The aim of the study was to investigate the genetic diversity of these C. diphtheriae isolates using whole genome sequencing. Methods: Isolates were characterized by genome wide comparison using single nucleotide polymorphism or core genome multilocus sequence typing, and by searching sequence data for antimicrobial resistance genes and genes involved in diphtheria toxin production. Results: Genetic diversity between the isolates was high, with no clear distribution over time or place. C. belfantii isolates were separated from other strains, and were strongly associated with respiratory infections (OR = 57). Two clusters, limited in time and space, were identified. Almost 40% of strains carried resistance genes against tetracycline or sulfonamides, mostly from skin infections. Microbiological tests showed that 55% of isolates were resistant to penicillin, but did not carry genes conferring β-lactam resistance. Diphtheria toxin gene with no non-synonymous mutation was found in three isolates only. Conclusion: This study showed that sequencing can provide valuable information complementing routine microbiological and epidemiological investigations. It allowed us to identify unknown clusters, evaluate antimicrobial resistances more broadly and support toxigenicity results obtained by PCR. For these reasons, C. diphtheriae surveillance could strongly benefit from the routine implementation of whole genome sequencing.


2020 ◽  
Vol 11 ◽  
Author(s):  
Grazielle Lima Rodrigues ◽  
Pedro Panzenhagen ◽  
Rafaela Gomes Ferrari ◽  
Anamaria dos Santos ◽  
Vania Margaret Flosi Paschoalin ◽  
...  

2015 ◽  
Vol 59 (4) ◽  
pp. 2006-2015 ◽  
Author(s):  
Beatriz Romero-Hernández ◽  
Ana P. Tedim ◽  
José Francisco Sánchez-Herrero ◽  
Pablo Librado ◽  
Julio Rozas ◽  
...  

ABSTRACTThe aim of this work was to characterize the antibiotic susceptibility and genetic diversity of 41Streptococcus gallolyticussubsp.gallolyticusisolates: 18 isolates obtained from animals and 23 human clinical isolates. Antibiotic susceptibility was determined by the semiautomatic Wider system and genetic diversity by pulsed-field gel electrophoresis (PFGE) with SmaI. Animal isolates grouped separately in the PFGE analysis, but no statistical differences in antimicrobial resistance were found between the two groups. The LMG 17956 sequence type 28 (ST28) strain recovered from the feces of a calf exhibited high levels of resistance to vancomycin and teicoplanin (MIC, ≥256 mg/liter). Its glycopeptide resistance mechanism was characterized by Southern blot hybridization and a primer-walking strategy, and finally its genome, determined by whole-genome sequencing, was compared with four closely relatedS. gallolyticussubsp.gallolyticusgenomes. Hybridization experiments demonstrated that a Tn1546-like element was integrated into the bacterial chromosome. In agreement with this finding, whole-genome sequencing confirmed a partial deletion of thevanY-vanZregion and partial duplication of thevanHgene. The comparative genomic analyses revealed that the LMG 17956 ST28 strain had acquired an unusually high number of transposable elements and had experienced extensive chromosomal rearrangements, as well as gene gain and loss events. In conclusion,S. gallolyticussubsp.gallolyticusisolates from animals seem to belong to lineages separate from those infecting humans. In addition, we report a glycopeptide-resistant isolate from a calf carrying a Tn1546-like element integrated into its chromosome.


2016 ◽  
Vol 60 (3) ◽  
pp. 1935-1938 ◽  
Author(s):  
Chang-Wei Lei ◽  
An-Yun Zhang ◽  
Hong-Ning Wang ◽  
Bi-Hui Liu ◽  
Li-Qin Yang ◽  
...  

SXT/R391 integrative and conjugative elements (ICEs) were detected in 8 out of 125Proteus mirabilisisolates from food-producing animals in China. Whole-genome sequencing revealed that seven ICEs were identical to ICEPmiJpn1, carrying the cephalosporinase geneblaCMY-2. Another one, designated ICEPmiChn1, carried five resistance genes. All eight ICEs could be transferred toEscherichia colivia conjugation. The results highlight the idea that animal farms are important reservoir of the SXT/R391 ICE-containingP. mirabilis.


2016 ◽  
Vol 54 (4) ◽  
pp. 1008-1016 ◽  
Author(s):  
Lena Strauß ◽  
Ulla Ruffing ◽  
Salim Abdulla ◽  
Abraham Alabi ◽  
Ruslan Akulenko ◽  
...  

Staphylococcus aureusis a major bacterial pathogen causing a variety of diseases ranging from wound infections to severe bacteremia or intoxications. Besides host factors, the course and severity of disease is also widely dependent on the genotype of the bacterium. Whole-genome sequencing (WGS), followed by bioinformatic sequence analysis, is currently the most extensive genotyping method available. To identify clinically relevant staphylococcal virulence and resistance genes in WGS data, we developed anin silicotyping scheme for the software SeqSphere+(Ridom GmbH, Münster, Germany). The implemented target genes (n= 182) correspond to those queried by the IdentibacS. aureusGenotyping DNA microarray (Alere Technologies, Jena, Germany). Thein silicoscheme was evaluated by comparing the typing results of microarray and of WGS for 154 humanS. aureusisolates. A total of 96.8% (n= 27,119) of all typing results were equally identified with microarray and WGS (40.6% present and 56.2% absent). Discrepancies (3.2% in total) were caused by WGS errors (1.7%), microarray hybridization failures (1.3%), wrong prediction of ambiguous microarray results (0.1%), or unknown causes (0.1%). Superior to the microarray, WGS enabled the distinction of allelic variants, which may be essential for the prediction of bacterial virulence and resistance phenotypes. Multilocus sequence typing clonal complexes and staphylococcal cassette chromosomemecelement types inferred from microarray hybridization patterns were equally determined by WGS. In conclusion, WGS may substitute array-based methods due to its universal methodology, open and expandable nature, and rapid parallel analysis capacity for different characteristics in once-generated sequences.


2020 ◽  
Vol 6 (7) ◽  
Author(s):  
Bede Constantinides ◽  
Kevin K. Chau ◽  
T. Phuong Quan ◽  
Gillian Rodger ◽  
Monique I. Andersson ◽  
...  

Escherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonized with diverse populations of E. coli , Klebsiella pneumoniae and Klebsiella oxytoca , including both antimicrobial-resistant and susceptible strains. Using whole-genome sequencing of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies, which may vary as a result of different inputs and selection pressures. Whole-genome sequencing of 46 contemporaneous patient isolates identified one (2 %; 95 % CI 0.05–11 %) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10 % of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including bla CTX-M, bla SHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention. This article contains data hosted by Microreact.


2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Wenming Zhu ◽  
Adrian Lawsin ◽  
Rebecca L. Lindsey ◽  
Dhwani Batra ◽  
Kristen Knipe ◽  
...  

ABSTRACT Four Enterobacteriaceae clinical isolates bearing mcr-1 gene-harboring plasmids were characterized. All isolates demonstrated the ability to transfer colistin resistance to Escherichia coli; plasmids were stable in conjugants after multiple passages on nonselective media. mcr-1 was located on an IncX4 (n = 3) or IncN (n = 1) plasmid. The IncN plasmid harbored 13 additional antimicrobial resistance genes. Results indicate that the mcr-1-bearing plasmids in this study were highly transferable in vitro and stable in the recipients.


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