scholarly journals Genomic epidemiology of tuberculosis in eastern Malaysia: insights for strengthening public health responses

2021 ◽  
Vol 7 (5) ◽  
Author(s):  
Arnold Bainomugisa ◽  
Ella M. Meumann ◽  
Giri Shan Rajahram ◽  
Rick Twee-Hee Ong ◽  
Lachlan Coin ◽  
...  

Tuberculosis is a leading public health priority in eastern Malaysia. Knowledge of the genomic epidemiology of tuberculosis can help tailor public health interventions. Our aims were to determine tuberculosis genomic epidemiology and characterize resistance mutations in the ethnically diverse city of Kota Kinabalu, Sabah, located at the nexus of Malaysia, Indonesia, Philippines and Brunei. We used an archive of prospectively collected Mycobacterium tuberculosis samples paired with epidemiological data. We collected sputum and demographic data from consecutive consenting outpatients with pulmonary tuberculosis at the largest tuberculosis clinic from 2012 to 2014, and selected samples from tuberculosis inpatients from the tertiary referral centre during 2012–2014 and 2016–2017. Two hundred and eight M . tuberculosis sequences were available for analysis, representing 8 % of cases notified during the study periods. Whole-genome phylogenetic analysis demonstrated that most strains were lineage 1 (195/208, 93.8 %), with the remainder being lineages 2 (8/208, 3.8 %) or 4 (5/208, 2.4 %). Lineages or sub-lineages were not associated with patient ethnicity. The lineage 1 strains were diverse, with sub-lineage 1.2.1 being dominant (192, 98 %). Lineage 1.2.1.3 isolates were geographically most widely distributed. The greatest diversity occurred in a border town sub-district. The time to the most recent common ancestor for the three major lineage 1.2.1 clades was estimated to be the year 1966 (95 % HPD 1948–1976). An association was found between failure of culture conversion by week 8 of treatment and infection with lineage 2 (4/6, 67 %) compared with lineage 1 strains (4/83, 5 %) (P<0.001), supporting evidence of greater virulence of lineage 2 strains. Eleven potential transmission clusters (SNP difference ≤12) were identified; at least five included people living in different sub-districts. Some linked cases spanned the whole 4-year study period. One cluster involved a multidrug-resistant tuberculosis strain matching a drug-susceptible strain from 3 years earlier. Drug resistance mutations were uncommon, but revealed one phenotype–genotype mismatch in a genotypically multidrug-resistant isolate, and rare nonsense mutations within the katG gene in two isolates. Consistent with the regionally mobile population, M. tuberculosis strains in Kota Kinabalu were diverse, although several lineage 1 strains dominated and were locally well established. Transmission clusters – uncommonly identified, likely attributable to incomplete sampling – showed clustering occurring across the community, not confined to households or sub-districts. The findings indicate that public health priorities should include active case finding and early institution of tuberculosis management in mobile populations, while there is a need to upscale effective contact investigation beyond households to include other contacts within social networks.

2020 ◽  
Vol 2 (12) ◽  
Author(s):  
Geoffrey Foster ◽  
Manal AbuOun ◽  
Romain Pizzi ◽  
Bryn Tennant ◽  
Margaret McCall ◽  
...  

The ST307 multidrug-resistant CTX-M-15-producing Klebsiella pneumoniae is an emerging pathogen, which has become disseminated worldwide in humans but is rarely reported from other reservoirs. We report the first isolation of K. pneumoniae from an animal in Europe and also from a reptile, a captive tortoise, whose death it probably caused. Detection of this clone from an animal adds to evidence of niche expansion in non-human environments, where it may amplify, recycle and become of greater public health concern.


2021 ◽  
Author(s):  
Mattia Palmieri ◽  
Kelly L. Wyres ◽  
Caroline Mirande ◽  
Zhao Qiang ◽  
Ye Liyan ◽  
...  

Klebsiella pneumoniae is a frequent cause of nosocomial and severe community-acquired infections. Multidrug-resistant (MDR) and hypervirulent (hv) strains represent major threats, and tracking their emergence, evolution and the emerging convergence of MDR and hv traits is of major importance. We employed whole-genome sequencing (WGS) to study the evolution and epidemiology of a large longitudinal collection of clinical K. pneumoniae isolates from the H301 hospital in Beijing, China. Overall, the population was highly diverse, although some clones were predominant. Strains belonging to clonal group (CG) 258 were dominant, and represented the majority of carbapenemase-producers. While CG258 strains showed high diversity, one clone, ST11-KL47, represented the majority of isolates, and was highly associated with the KPC-2 carbapenemase and several virulence factors, including a virulence plasmid. The second dominant clone was CG23, which is the major hv clone globally. While it is usually susceptible to multiple antibiotics, we found some isolates harbouring MDR plasmids encoding for ESBLs and carbapenemases. We also reported the local emergence of a recently described high-risk clone, ST383. Conversely to strains belonging to CG258, which are usually associated to KPC-2, ST383 strains seem to readily acquire carbapenemases of different types. Moreover, we found several ST383 strains carrying the hypervirulence plasmid. Overall, we detected about 5 % of simultaneous carriage of AMR genes (ESBLs or carbapenemases) and hypervirulence genes. Tracking the emergence and evolution of such strains, causing severe infections with limited treatment options, is fundamental in order to understand their origin and evolution and to limit their spread. This article contains data hosted by Microreact.


2020 ◽  
Vol 6 (9) ◽  
Author(s):  
Scott Van Nguyen ◽  
Dechamma Mundanda Muthappa ◽  
Athmanya K. Eshwar ◽  
James F. Buckley ◽  
Brenda P. Murphy ◽  
...  

Food-associated outbreaks linked to enteropathogenic Yersinia enterocolitica are of concern to public health. Pigs and their meat are recognized risk factors for transmission of Y. enterocolitica . This study aimed to describe the comparative genomics of Y. enterocolitica along with a number of misclassified Yersinia isolates, now constituting the recently described Yersinia hibernica . The latter was originally cultured from an environmental sample taken at a pig slaughterhouse. Unique features were identified in the genome of Y. hibernica, including a novel integrative conjugative element (ICE), denoted as ICE Yh-1 contained within a 255 kbp region of plasticity. In addition, a zebrafish embryo infection model was adapted and applied to assess the virulence potential among Yersinia isolates including Y. hibernica .


2020 ◽  
Vol 6 (11) ◽  
Author(s):  
Hélène Gingras ◽  
Kévin Patron ◽  
Philippe Leprohon ◽  
Marc Ouellette

We report on the combination of chemical mutagenesis, azithromycin selection and next-generation sequencing (Mut-Seq) for the identification of small nucleotide variants that decrease the susceptibility of Streptococcus pneumoniae to the macrolide antibiotic azithromycin. Mutations in the 23S ribosomal RNA or in ribosomal proteins can confer resistance to macrolides and these were detected by Mut-Seq. By concentrating on recurrent variants, we could associate mutations in genes implicated in the metabolism of glutamine with decreased azithromycin susceptibility among S. pneumoniae mutants. Glutamine synthetase catalyses the transformation of glutamate and ammonium into glutamine and its chemical inhibition is shown to sensitize S. pneumoniae to antibiotics. A mutation affecting the ribosomal-binding site of a putative ribonuclease J2 is also shown to confer low-level resistance. Mut-Seq has the potential to reveal chromosomal changes enabling high resistance as well as novel events conferring more subtle phenotypes.


Author(s):  
Aleksandra Trościańczyk ◽  
Aneta Nowakiewicz ◽  
Sebastian Gnat ◽  
Dominik Łagowski ◽  
Marcelina Osińska ◽  
...  

Introduction. The possible transfer of antimicrobial resistance genes between Enterococcus faecium isolates from humans and different animal species, including those not covered by monitoring programs (e.g. pet and wildlife), poses a serious threat to public health. Hypothesis/Gap Statement. Little is known about occurrence and mechanisms of phenomenon of multidrug resistance of E. faecium isolated from various host species in Poland. Aim. The aim of the study was to characterize multidrug-resistant E. faecium isolated from humans and animals (livestock, pets and wildlife) in terms of the occurrence of genetic markers determining resistance. Methodology. Bacterial isolates were tested for phenotypic resistance and the presence of genes encoding resistance to macrolides, tetracycline, aminoglycosides, aminocyclitols and phenicols as well as efflux pump (emeA), resolvase (tndX) and integrase (Int-Tn) genes. The quinolone resistance-determining regions of gyrA and parC were sequenced. Results. Human isolates of E. faecium were characterized by high-level resistance to: ciprofloxacin, enrofloxacin, erythromycin (100 %), as well, as aminoglycosides resistance (kanamycin – 100%, streptomycin – 78 %, gentamicin – 78%). Regardless of the animal species, high level of resistance of E. faecium to tetracycline (from 88–100 %), erythromycin (from 82–94 %) and kanamycin (from 36–100 %) was observed. All E. faecium isolates from wildlife were resistant to fluoroquinolones. However, full susceptibility to vancomycin was observed in all isolates tested. Phenotypic antimicrobial resistance of E. faecium was identified in the presence of the following resistance genes: erm(B) (70%), msr(A) (50 %), tet(L) (35 %), tet(K) (34 %), tet(M) (76 %), aac(6’)-Ie-aph(2″)-Ia (25%), ant(6)-Ia (31%), aph(3)-IIIa (68 %), (tndX) (23 %), and integrase gene (Int-Tn) (34 %). A correlation between an amino acid substitution at positions 83 and 87 of gyrA and position 80 of parC and the high-level fluoroquinolone resistance in E. faecium has been observed as well. Conclusion. The level and range of antimicrobial resistance and the panel of resistance determinants is comparable between E. faecium isolates, despite host species.


2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Kyrylo Bessonov ◽  
Chad Laing ◽  
James Robertson ◽  
Irene Yong ◽  
Kim Ziebell ◽  
...  

Escherichia coli is a priority foodborne pathogen of public health concern and phenotypic serotyping provides critical information for surveillance and outbreak detection activities. Public health and food safety laboratories are increasingly adopting whole-genome sequencing (WGS) for characterizing pathogens, but it is imperative to maintain serotype designations in order to minimize disruptions to existing public health workflows. Multiple in silico tools have been developed for predicting serotypes from WGS data, including SRST2, SerotypeFinder and EToKi EBEis, but these tools were not designed with the specific requirements of diagnostic laboratories, which include: speciation, input data flexibility (fasta/fastq), quality control information and easily interpretable results. To address these specific requirements, we developed ECTyper (https://github.com/phac-nml/ecoli_serotyping) for performing both speciation within Escherichia and Shigella , and in silico serotype prediction. We compared the serotype prediction performance of each tool on a newly sequenced panel of 185 isolates with confirmed phenotypic serotype information. We found that all tools were highly concordant, with 92–97 % for O-antigens and 98–100 % for H-antigens, and ECTyper having the highest rate of concordance. We extended the benchmarking to a large panel of 6954 publicly available E. coli genomes to assess the performance of the tools on a more diverse dataset. On the public data, there was a considerable drop in concordance, with 75–91 % for O-antigens and 62–90 % for H-antigens, and ECTyper and SerotypeFinder being the most concordant. This study highlights that in silico predictions show high concordance with phenotypic serotyping results, but there are notable differences in tool performance. ECTyper provides highly accurate and sensitive in silico serotype predictions, in addition to speciation, and is designed to be easily incorporated into bioinformatic workflows.


2020 ◽  
Author(s):  
Gerald Tegha ◽  
Emily J. Ciccone ◽  
Robert Krysiak ◽  
James Kaphatika ◽  
Tarsizio Chikaonda ◽  
...  

Antimicrobial resistance (AMR) is a global threat, including in sub-Saharan Africa. However, little is known about the genetics of resistant bacteria in the region. In Malawi, there is growing concern about increasing rates of antimicrobial resistance to most empirically used antimicrobials. The highly drug resistant Escherichia coli sequence type (ST) 131, which is associated with the extended spectrum β-lactamase blaCTX-M-15 , has been increasing in prevalence globally. Previous data from isolates collected between 2006 and 2013 in southern Malawi have revealed the presence of ST131 and the blaCTX-M-15 gene in the country. We performed whole genome sequencing (WGS) of 58 clinical E. coli isolates at Kamuzu Central Hospital, a tertiary care centre in central Malawi, collected from 2012 to 2018. We used Oxford Nanopore Technologies (ONT) sequencing, which was performed in Malawi. We show that ST131 is observed more often (14.9% increasing to 32.8%) and that the blaCTX-M-15 gene is occurring at a higher frequency (21.3% increasing to 44.8%). Phylogenetics indicates that isolates are highly related between the central and southern geographic regions and confirms that ST131 isolates are contained in a single group. All AMR genes, including blaCTX-M-15 , were widely distributed across sequence types. We also identified an increased number of ST410 isolates, which in this study tend to carry a plasmid-located copy of blaCTX-M-15 gene at a higher frequency than blaCTX-M-15 occurs in ST131. This study confirms the expanding nature of ST131 and the wide distribution of the blaCTX-M-15 gene in Malawi. We also highlight the feasibility of conducting longitudinal genomic epidemiology studies of important bacteria with the sequencing done on site using a nanopore platform that requires minimal infrastructure.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
John Maina ◽  
Perpetual Ndung’u ◽  
Anne Muigai ◽  
John Kiiru

Objective. This cross-sectional study conducted in Kibera, Kenya, sought to gain insights on relative microbial contamination levels of popular unprocessed food types, determine antimicrobial resistance (AMR) burden and the carriage of integrons that are essential elements for spreading antimicrobial resistance genes (ARG). Foods analysed consisted of cooked vegetables (kale, cabbage, and nightshades), boiled cereal foods (beans, rice, and Githeri, which is a mixture of beans and maize), meat, Omena fish (fried silver cyprinids), and Ugali (a product of simmered maize flour in boiled water). Results. The analysis detected contamination levels exceeding 2×104 c.f.u. ml−1 in 106 (38 %) of the 281 ready-to-eat foods analysed. The majority of food types had microbial contaminations of between 4.0×104 and 2.3×106 c.f.u. ml−1. Kale was the most contaminated with a mean of 2.3×106 c.f.u. ml−1, while Omena was the least contaminated with 4.0×104 c.f.u. ml−1. Foods sold close to open sewage and refuse sites were more contaminated than those sold in relatively ‘cleaner’ settings (P <0.0001, O.R 0.1162, C.I 0.1162–0.120). A total of 405 bacterial isolates were recovered and included; Klebsiella spp 116 (29 %), Escherichia coli 104 (26 %), Enterobacter agglomerans 88 (22 %), Proteus mirabilis 30 (7 %), Salmonella spp 28 (7 %), Citrobacter freundii 27 (7 %) and Serratia marcescens 12 (3 %). Imipenem (IPM, 100 %) was the most effective antimicrobial agent, followed by cefepime (98 %). Ampicillin (AMP, 33 %), trimethoprim (TMP, 27 %), and sulfamethoxazole (SMX, 23 %) on the other hand, were the least effective antimicrobials. The analysis also found ten isolates (2 %) that had co-resistance to third-generation cephalosporins, fluoroquinolone (CIP), quinolones (NAL) and aminoglycosides (GEN); hereby we refer to this phenotype as the βFQA. The prevalence of multidrug-resistant (MDR) strains was 23 % (93), while that of extended-spectrum β-lactamases (ESBL) producing strains was 4 % (17). The bla TEM was the most prevalent (55 %) β-lactamase (bla) gene among the screened 93 MDR-strains. Carriage of class one integrons (intI1) was more common (23 %) than intl2 (3 %) among these MDR-strains. Bacterial diversity analysis using the GTG5-PCR found no significant clusters for analysed E. coli and K. pneumoniae, suggesting recovered isolates were genetically diverse and not due to non-clonal expansion. The findings of this study are an indication that contaminated foods can be a reservoir for enteric pathogens and a source of AMR strains.


2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Lingzi Xiaoli ◽  
Eileen Benoliel ◽  
Yanhui Peng ◽  
Janessa Aneke ◽  
Pamela K. Cassiday ◽  
...  

Between July 2018 and May 2019, Corynebacterium diphtheriae was isolated from eight patients with non-respiratory infections, seven of whom experienced homelessness and had stayed at shelters in King County, WA, USA. All isolates were microbiologically identified as nontoxigenic C. diphtheriae biovar mitis. Whole-genome sequencing confirmed that all case isolates were genetically related, associated with sequence type 445 and differing by fewer than 24 single-nucleotide polymorphisms (SNPs). Compared to publicly available C. diphtheriae genomic data, these WA isolates formed a discrete cluster with SNP variation consistent with previously reported outbreaks. Virulence-related gene content variation within the highly related WA cluster isolates was also observed. These results indicated that genome characterization can readily support epidemiology of nontoxigenic C. diphtheriae .


2021 ◽  
Author(s):  
Kara K. Tsang ◽  
Finlay Maguire ◽  
Haley L. Zubyk ◽  
Sommer Chou ◽  
Arman Edalatmand ◽  
...  

Diagnosing antimicrobial resistance (AMR) in the clinic is based on empirical evidence and current gold standard laboratory phenotypic methods. Genotypic methods have the potential advantages of being faster and cheaper, and having improved mechanistic resolution over phenotypic methods. We generated and applied rule-based and logistic regression models to predict the AMR phenotype from Escherichia coli and Pseudomonas aeruginosa multidrug-resistant clinical isolate genomes. By inspecting and evaluating these models, we identified previously unknown β-lactamase substrate activities. In total, 22 unknown β-lactamase substrate activities were experimentally validated using targeted gene expression studies. Our results demonstrate that generating and analysing predictive models can help guide researchers to the mechanisms driving resistance and improve annotation of AMR genes and phenotypic prediction, and suggest that we cannot solely rely on curated knowledge to predict resistance phenotypes.


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