scholarly journals Whole genome sequencing of Clostridioides difficile PCR ribotype 046 suggests transmission between pigs and humans

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244227
Author(s):  
Anders Werner ◽  
Paula Mölling ◽  
Anna Fagerström ◽  
Fredrik Dyrkell ◽  
Dimitrios Arnellos ◽  
...  

Background A zoonotic association has been suggested for several PCR ribotypes (RTs) of Clostridioides difficile. In central parts of Sweden, RT046 was found dominant in neonatal pigs at the same time as a RT046 hospital C. difficile infection (CDI) outbreak occurred in the southern parts of the country. Objective To detect possible transmission of RT046 between pig farms and human CDI cases in Sweden and investigate the diversity of RT046 in the pig population using whole genome sequencing (WGS). Methods WGS was performed on 47 C. difficile isolates from pigs (n = 22), the farm environment (n = 7) and human cases of CDI (n = 18). Two different core genome multilocus sequencing typing (cgMLST) schemes were used together with a single nucleotide polymorphisms (SNP) analysis and the results were related to time and location of isolation of the isolates. Results The pig isolates were closely related (≤6 cgMLST alleles differing in both cgMLST schemes) and conserved over time and were clearly separated from isolates from the human hospital outbreak (≥76 and ≥90 cgMLST alleles differing in the two cgMLST schemes). However, two human isolates were closely related to the pig isolates, suggesting possible transmission. The SNP analysis was not more discriminate than cgMLST. Conclusion No general pattern suggesting zoonotic transmission was apparent between pigs and humans, although contrasting results from two isolates still make transmission possible. Our results support the need for high resolution WGS typing when investigating hospital and environmental transmission of C. difficile.

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 201
Author(s):  
Sang Mee Hwang ◽  
Hee Won Cho ◽  
Tae Yeul Kim ◽  
Jeong Su Park ◽  
Jongtak Jung ◽  
...  

Carbapenem-resistant Acinetobacter baumannii (CRAB) outbreaks in hospital settings challenge the treatment of patients and infection control. Understanding the relatedness of clinical isolates is important in distinguishing outbreak isolates from sporadic cases. This study investigated 11 CRAB isolates from a hospital outbreak by whole-genome sequencing (WGS), utilizing various bioinformatics tools for outbreak analysis. The results of multilocus sequence typing (MLST), single nucleotide polymorphism (SNP) analysis, and phylogenetic tree analysis by WGS through web-based tools were compared, and repetitive element polymerase chain reaction (rep-PCR) typing was performed. Through the WGS of 11 A. baumannii isolates, three clonal lineages were identified from the outbreak. The coexistence of blaOXA-23, blaOXA-66, blaADC-25, and armA with additional aminoglycoside-inactivating enzymes, predicted to confer multidrug resistance, was identified in all isolates. The MLST Oxford scheme identified three types (ST191, ST369, and ST451), and, through whole-genome MLST and whole-genome SNP analyses, different clones were found to exist within the MLST types. wgSNP showed the highest discriminatory power with the lowest similarities among the isolates. Using the various bioinformatics tools for WGS, CRAB outbreak analysis was applicable and identified three discrete clusters differentiating the separate epidemiologic relationships among the isolates.


Author(s):  
Emmanuel Lecorche ◽  
Côme Daniau ◽  
Kevin La ◽  
Faiza Mougari ◽  
Hanaa Benmansour ◽  
...  

Abstract Background Post-surgical infections due to Mycobacterium chimaera appeared as a novel nosocomial threat in 2015, with a worldwide outbreak due to contaminated heater-cooler units used in open chest surgery. We report the results of investigations conducted in France including whole genome sequencing comparison of patient and HCU isolates. Methods We sought M. chimaera infection cases from 2010 onwards through national epidemiological investigations in healthcare facilities performing cardiopulmonary bypass together with a survey on good practices and systematic heater-cooler unit microbial analyses. Clinical and HCU isolates were subjected to whole genome sequencing analyzed with regards to the reference outbreak strain Zuerich-1. Results Only two clinical cases were shown to be related to the outbreak, although 23% (41/175) heater-cooler units were declared positive for M. avium complex. Specific measures to prevent infection were applied in 89% (50/56) healthcare facilities although only 14% (8/56) of them followed the manufacturer maintenance recommendations. Whole genome sequencing comparison showed that the clinical isolates and 72% (26/36) of heater-cooler unit isolates belonged to the epidemic cluster. Within clinical isolates, 5 to 9 non-synonymous single nucleotide polymorphisms were observed, among which an in vivo mutation in a putative efflux pump gene observed in a clinical isolate obtained for one patient under antimicrobial treatment. Conclusions Cases of post-surgical M. chimaera infections were declared to be rare in France, although heater-cooler units were contaminated as in other countries. Genomic analyses confirmed the connection to the outbreak and identified specific single nucleotide polymorphisms, including one suggesting fitness evolution in vivo.


Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2454
Author(s):  
Rebecca N. Bland ◽  
Jared D. Johnson ◽  
Joy G. Waite-Cusic ◽  
Alexandra J. Weisberg ◽  
Elizabeth R. Riutta ◽  
...  

Recent listeriosis outbreaks linked to fresh produce suggest the need to better understand and mitigate L. monocytogenes contamination in packing and processing environments. Using whole genome sequencing (WGS) and phenotype screening assays for sanitizer tolerance, we characterized 48 L. monocytogenes isolates previously recovered from environmental samples in five produce handling facilities. Within the studied population there were 10 sequence types (STs) and 16 cgMLST types (CTs). Pairwise single nucleotide polymorphisms (SNPs) ranged from 0 to 3047 SNPs within a CT, revealing closely and distantly related isolates indicative of both sporadic and continuous contamination events within the facility. Within Facility 1, we identified a closely related cluster (0–2 SNPs) of isolates belonging to clonal complex 37 (CC37; CT9492), with isolates recovered during sampling events 1-year apart and in various locations inside and outside the facility. The accessory genome of these CC37 isolates varied from 94 to 210 genes. Notable genetic elements and mutations amongst the isolates included the bcrABC cassette (2/48), associated with QAC tolerance; mutations in the actA gene on the Listeria pathogenicity island (LIPI) 1 (20/48); presence of LIPI-3 (21/48) and LIPI-4 (23/48). This work highlights the potential use of WGS in tracing the pathogen within a facility and understanding properties of L. monocytogenes in produce settings.


2020 ◽  
Vol 189 (8) ◽  
pp. 841-849
Author(s):  
Fermín Acosta ◽  
Ana Fernández-Cruz ◽  
Sandra R Maus ◽  
Pedro J Sola-Campoy ◽  
Mercedes Marín ◽  
...  

Abstract In 2013–2014, an outbreak involving 14 patients infected by an extensively drug-resistant strain of Pseudomonas aeruginosa was detected in a hospital in Madrid, Spain. Our objective was to evaluate an alternative strategy for investigating the outbreak in depth by means of molecular and genomic approaches. Pulsed-field gel electrophoresis (PFGE) was applied as a first-line approach, followed by a more refined whole genome sequencing analysis. Single nucleotide polymorphisms identified by whole genome sequencing were used to design a specific polymerase chain reaction (PCR) for screening unsuspected cases infected by the outbreak strain. Whole genome sequencing alerted us to the existence of greater genetic diversity than was initially assumed, splitting the PFGE-associated outbreak isolates into 4 groups, 2 of which represented coincidental transmission unrelated to the outbreak. A multiplex allele-specific PCR targeting outbreak-specific single nucleotide polymorphisms was applied to 290 isolates, which allowed us to identify 25 additional cases related to the outbreak during 2011–2017. Whole genome sequencing coupled with an outbreak-strain-specific PCR enabled us to markedly redefine the initial picture of the outbreak by 1) ruling out initially suspected cases, 2) defining likely independent coincidental transmission events, 3) predating the starting point of the outbreak, 4) capturing new unsuspected cases, and 5) revealing that the outbreak was still active.


2016 ◽  
Vol 144 (9) ◽  
pp. 1991-1998 ◽  
Author(s):  
A. C. BOWEN ◽  
T. HARRIS ◽  
D. C. HOLT ◽  
P. M. GIFFARD ◽  
J. R. CARAPETIS ◽  
...  

SUMMARYImpetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context beingStreptococcus pyogenes[or group AStreptococcus(GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0–3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches.


2019 ◽  
Author(s):  
Jung-Ki Yoon ◽  
Taek Soo Kim ◽  
Jong-Il Kim ◽  
Jae-Joon Yim

Abstract Background : Nontuberculous mycobacterium (NTM) species are ubiquitous microorganisms. NTM pulmonary disease (NTM-PD) is caused not by human-to-human transmission but by independent environmental acquisition. However, recent studies using next-generation sequencing (NGS) have reported trans-continental spread of Mycobacterium abscessus among patients with cystic fibrosis. Results : We investigated NTM genomes through NGS to examine transmission patterns in three pairs of co-habiting NTM-PD patients who were suspected of patient-to-patient transmission. Three pairs of patients with NTM-PD co-habiting for at least 15 years were enrolled: a mother and a daughter with M. avium PD, a couple with M. intracellulare PD, and a second couple, one of whom was infected with M. intracellulare PD and the other of whom was infected with M. abscessus subsp. massiliense PD. Whole genome sequencing was performed using NTM colonies isolated from patients and environmental specimens. Genetic distances were estimated based on single nucleotide polymorphisms (SNPs) in the NTM genomes. Comparing SNPs in the consensus regions, the minimum pairwise SNP distances of NTM isolates derived from the two pairs of patients infected with the same NTM species were over 10,000. In phylogenetic analysis, the NTM isolates from patients with M. avium PD clustered with isolates from different environmental sources. Conclusions : In conclusion, considering the genetic distances between NTM strains, the likelihood of patient-to-patient transmission in pairs of co-habiting NTM-PD patients without overt immune deficiency is minimal.


2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Bradley T Endres ◽  
Khurshida Begum ◽  
Hua Sun ◽  
Seth T Walk ◽  
Ali Memariani ◽  
...  

Abstract Background The epidemic Clostridioides difficile ribotype 027 strain resulted from the dissemination of 2 separate fluoroquinolone-resistant lineages: FQR1 and FQR2. Both lineages were reported to originate in North America; however, confirmatory large-scale investigations of C difficile ribotype 027 epidemiology using whole genome sequencing has not been undertaken in the United States. Methods Whole genome sequencing and single-nucleotide polymorphism (SNP) analysis was performed on 76 clinical ribotype 027 isolates obtained from hospitalized patients in Texas with C difficile infection and compared with 32 previously sequenced worldwide strains. Maximum-likelihood phylogeny based on a set of core genome SNPs was used to construct phylogenetic trees investigating strain macro- and microevolution. Bayesian phylogenetic and phylogeographic analyses were used to incorporate temporal and geographic variables with the SNP strain analysis. Results Whole genome sequence analysis identified 2841 SNPs including 900 nonsynonymous mutations, 1404 synonymous substitutions, and 537 intergenic changes. Phylogenetic analysis separated the strains into 2 prominent groups, which grossly differed by 28 SNPs: the FQR1 and FQR2 lineages. Five isolates were identified as pre-epidemic strains. Phylogeny demonstrated unique clustering and resistance genes in Texas strains indicating that spatiotemporal bias has defined the microevolution of ribotype 027 genetics. Conclusions Clostridioides difficile ribotype 027 lineages emerged earlier than previously reported, coinciding with increased use of fluoroquinolones. Both FQR1 and FQR2 ribotype 027 epidemic lineages are present in Texas, but they have evolved geographically to represent region-specific public health threats.


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