Pathogenic Escherichia coli Possess Elevated Growth Rates under Exposure to Sub-Inhibitory Concentrations of Azithromycin

Antimicrobial resistance (AMR) has been identified by the World Health Organization (WHO) as one of the ten major threats to global health. Advances in technology, including whole-genome sequencing, have provided new insights into the origin and mechanisms of AMR. However, our understanding of the short-term impact of antimicrobial pressure and resistance on the physiology of bacterial populations is limited. We aimed to investigate morphological and physiological responses of clinical isolates of E. coli under short-term exposure to key antimicrobials. We performed whole-genome sequencing on twenty-seven E. coli isolates isolated from children with sepsis to evaluate their AMR gene content. We assessed their antimicrobial susceptibility profile and measured their growth dynamics and morphological characteristics under exposure to varying concentrations of ciprofloxacin, ceftriaxone, tetracycline, gentamicin, and azithromycin. AMR was common, with all organisms resistant to at least one antimicrobial; a total of 81.5% were multi-drug-resistant (MDR). We observed an association between resistance profile and morphological characteristics of the E. coli over a three-hour exposure to antimicrobials. Growth dynamics experiments demonstrated that resistance to tetracycline promoted the growth of E. coli under antimicrobial-free conditions, while resistance to the other antimicrobials incurred a fitness cost. Notably, antimicrobial exposure heterogeneously suppressed bacterial growth, but sub-MIC concentrations of azithromycin increased the maximum growth rate of the clinical isolates. Our results outline complex interactions between organism and antimicrobials and raise clinical concerns regarding exposure of sub-MIC concentrations of specific antimicrobials.

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Frequency and Mechanisms of Spontaneous Fosfomycin Nonsusceptibility Observed upon Disk Diffusion Testing of Escherichia coli

Journal of Clinical Microbiology ◽

10.1128/jcm.01368-17 ◽

2017 ◽

Vol 56 (1) ◽

Cited By ~ 16

Author(s):

Aaron E. Lucas ◽

Ryota Ito ◽

Mustapha M. Mustapha ◽

Christi L. McElheny ◽

Roberta T. Mettus ◽

...

Keyword(s):

Escherichia Coli ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Whole Genome ◽

Zone Of Inhibition ◽

Content Type ◽

E Coli ◽

Disk Diffusion Testing

ABSTRACTFosfomycin maintains activity against mostEscherichia coliclinical isolates, but the growth ofE. colicolonies within the zone of inhibition around the fosfomycin disk is occasionally observed upon susceptibility testing. We aimed to estimate the frequency of such nonsusceptible inner colony mutants and identify the underlying resistance mechanisms. Disk diffusion testing of fosfomycin was performed on 649 multidrug-resistantE. coliclinical isolates collected between 2011 and 2015. For those producing inner colonies inside the susceptible range, the parental strains and their representative inner colony mutants were subjected to MIC testing, whole-genome sequencing, reverse transcription-quantitative PCR (qRT-PCR), and carbohydrate utilization studies. Of the 649E. coliclinical isolates, 5 (0.8%) consistently produced nonsusceptible inner colonies. Whole-genome sequencing revealed the deletion ofuhpTencoding hexose-6-phosphate antiporter in 4 of theE. coliinner colony mutants, while the remaining mutant contained a nonsense mutation inuhpA. The expression ofuhpTwas absent in the mutant strains withuhpTdeletion and was not inducible in the strain with theuhpAmutation, unlike in its parental strain. All 5 inner colony mutants had reduced growth on minimal medium supplemented with glucose-6-phosphate. In conclusion, fosfomycin-nonsusceptible inner colony mutants can occur due to the loss of function or induction of UhpT but are rare among multidrug-resistantE. coliclinical strains. Considering that these mutants carry high biological costs, we suggest that fosfomycin susceptibility of strains that generate inner colony mutants can be interpreted on the basis of the zone of inhibition without accounting for the inner colonies.

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Mass Spectrometry–Based Escherichia coli H Antigen/Flagella Typing: Validation and Comparison with Traditional Serotyping

Clinical Chemistry ◽

10.1373/clinchem.2015.244236 ◽

2016 ◽

Vol 62 (6) ◽

pp. 839-847 ◽

Cited By ~ 11

Author(s):

Keding Cheng ◽

Yi-Min She ◽

Huixia Chui ◽

Larissa Domish ◽

Angela Sloan ◽

...

Keyword(s):

Mass Spectrometry ◽

Escherichia Coli ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Close Correlation ◽

Clinical Isolates ◽

Whole Genome ◽

Sequence Coverage ◽

E Coli ◽

Reference Strains

Abstract BACKGROUND Escherichia coli H antigen typing with antisera, a useful method for flagella clinical identification and classification, is a time-consuming process because of the need to induce flagella growth and the occurrence of undetermined strains. We developed an alternative rapid and analytically sensitive mass spectrometry (MS) method, termed MS-based H antigen typing (MS-H), and applied it at the protein sequence level for H antigen typing. We also performed a comparison with traditional serotyping on reference strains and clinical isolates. METHODS On the basis of international guidelines, the analytical selectivity and sensitivity, imprecision, correlation, repeatability, and reproducibility of the MS-H platform was evaluated using reference strains. Comparison of MS-H typing and serotyping was performed using 302 clinical isolates from 5 Canadian provinces, and discrepant results between the 2 platforms were resolved through whole genome sequencing. RESULTS Repeated tests on reference strain EDL933 demonstrated a lower limit of the measuring interval at the subsingle colony (16.97 μg or 1.465 × 107 cells) level and close correlation (r2 > 0.99) between cell culture biomass and sequence coverage. The CV was <10.0% among multiple repeats with 4 reference strains. Intra- and interlaboratory tests demonstrated that the MS-H method was robust and reproducible under various sample preparation and instrumentation conditions. Using discrepancy analysis via whole genome sequencing, performed on isolates with discrepant results, MS-H accurately identified 12.3% more isolates than conventional serotyping. CONCLUSIONS MS-H typing of E. coli is useful for fast and accurate flagella typing and could be very useful during E. coli outbreaks.

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Molecular Characteristics of Extraintestinal Pathogenic E. coli (ExPEC), Uropathogenic E. coli (UPEC), and Multidrug Resistant E. coli Isolated from Healthy Dogs in Spain. Whole Genome Sequencing of Canine ST372 Isolates and Comparison with Human Isolates Causing Extraintestinal Infections

Microorganisms ◽

10.3390/microorganisms8111712 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1712

Author(s):

Saskia-Camille Flament-Simon ◽

María de Toro ◽

Vanesa García ◽

Jesús E. Blanco ◽

Miguel Blanco ◽

...

Keyword(s):

Whole Genome Sequencing ◽

Genome Sequencing ◽

One Health ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Molecular Characteristics ◽

Whole Genome ◽

E Coli ◽

Healthy Dogs ◽

The One

Under a one health perspective and the worldwide antimicrobial resistance concern, we investigated extraintestinal pathogenic Escherichia coli (ExPEC), uropathogenic E. coli (UPEC), and multidrug resistant (MDR) E. coli from 197 isolates recovered from healthy dogs in Spain between 2013 and 2017. A total of 91 (46.2%) isolates were molecularly classified as ExPEC and/or UPEC, including 50 clones, among which (i) four clones were dominant (B2-CH14-180-ST127, B2-CH52-14-ST141, B2-CH103-9-ST372 and F-CH4-58-ST648) and (ii) 15 had been identified among isolates causing extraintestinal infections in Spanish and French humans in 2015 and 2016. A total of 28 (14.2%) isolates were classified as MDR, associated with B1, D, and E phylogroups, and included 24 clones, of which eight had also been identified among the human clinical isolates. We selected 23 ST372 strains, 21 from healthy dogs, and two from human clinical isolates for whole genome sequencing and built an SNP-tree with these 23 genomes and 174 genomes (128 from canine strains and 46 from human strains) obtained from public databases. These 197 genomes were segregated into six clusters. Cluster 1 comprised 74.6% of the strain genomes, mostly composed of canine strain genomes (p < 0.00001). Clusters 4 and 6 also included canine strain genomes, while clusters 2, 3, and 5 were significantly associated with human strain genomes. Finding several common clones and clone-related serotypes in dogs and humans suggests a potentially bidirectional clone transfer that argues for the one health perspective.

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Clinical and Genetic Characteristics of Extended-Spectrum Beta-Lactamase–Producing Enterobacteriaceae Among Canadian Children

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.693 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s167-s168

Author(s):

Nisha Thampi ◽

Jennifer Bowes ◽

Roberto Melano ◽

Nathalie Tijet ◽

Robert Slinger

Keyword(s):

Public Health ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Multidrug Resistant ◽

Clinical Isolates ◽

First Episode ◽

Whole Genome ◽

Comorbid Conditions ◽

Genetic Characteristics ◽

E Coli

Background: Infections with extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-E) in nonoutbreak settings have not demonstrated the presence of dominant strains. Our objective was to determine the incidence, clinical characteristics, and genetic characteristics of ESBL-E infections among a group of Canadian children. Methods: From 2012 through 2017, patients aged ≤18 years with first-episode ESBL-E infections who presented at a pediatric center were reviewed. All clinical isolates were phenotypically identified in the laboratory as ESBL-producers. Demographic and clinical data were collected, including comorbid conditions, presence of devices, and previous antibacterial exposure. Community-associated infection was defined as a positive culture from a sterile site within the first 48 hours of hospital admission and no healthcare exposure during the preceding year. Isolates were sent to the Public Health Ontario Laboratory for whole-genome sequencing. Multilocus sequence typing was used to determine clonal relationship. Results: During the study period, 102 patients were identified with first-episode ESBL-E infection, and the proportion of ESBL-E isolates among all clinical isolates of E. coli and Klebsiella spp increased from 0.6% to 2.6% between 2012 and 2017, respectively (P = .001). The median age was 1 year (interquartile range, 0.8–5 years). Women comprised 66% of cases. No comorbid conditions were noted among 58 patients (57%), and 24% had previous antibiotic exposure, most frequently a cephalosporin (16%). ESBL-E was most frequently isolated in the urine (91%) and least frequently in the blood (2.2%) and was predominantly Escherichia coli (90%). Infection was most frequently diagnosed in the outpatient setting (61%); there were 11 healthcare-associated infections. Whole-genome sequencing of ESBL-E isolates revealed predominance of blaCTX-M-15 (63 isolates, 62%) and blaCTX-M-27 (16%) genes, and sequence type (ST) 131 (41%). Mutations conferring fluoroquinolone nonsusceptibility were noted among 62 isolates (61%), most frequently associated with ST131 (38 of 62 isolates, 61%) and among all 5 isolates with ST1193, an emerging multidrug-resistant E. coli clone. In addition, 15 patients had recurrence of ESBL-E infection at median of 113 days (IQR, 26–208); blaCTX-M-27 was found in 33% of recurrent infections compared to 12% of primary infections (P = 0.045). Conclusions: This study is the first in Canada to provide whole-genome sequencing data regarding ESBL-E in a pediatric population. The gene blaCTX-M-15 and ST131 clone were predominant. More than 60% of infections were community associated and demonstrated cross resistance to fluoroquinolones. With 76% of infections in antibiotic-naïve children, ESBL-E is a public health concern, and a One Health approach is critical to understanding the epidemiology and curbing the spread of multidrug-resistant Enterobacteriaceae.Funding: NoneDisclosures: None

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Mycobacterium chimaera genomics with regard to epidemiological and clinical investigations conducted for the open-chest post-surgical Mycobacterium chimaera infections outbreak

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab192 ◽

2021 ◽

Author(s):

Emmanuel Lecorche ◽

Côme Daniau ◽

Kevin La ◽

Faiza Mougari ◽

Hanaa Benmansour ◽

...

Keyword(s):

Single Nucleotide Polymorphisms ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Clinical Isolates ◽

Whole Genome ◽

Nucleotide Polymorphisms ◽

Single Nucleotide ◽

Healthcare Facilities ◽

Open Chest

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.

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E. coli NF73-1 Isolated From NASH Patients Aggravates NAFLD in Mice by Translocating Into the Liver and Stimulating M1 Polarization

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.535940 ◽

2020 ◽

Vol 10 ◽

Author(s):

Yifan Zhang ◽

Weiwei Jiang ◽

Jun Xu ◽

Na Wu ◽

Yang Wang ◽

...

Keyword(s):

Gene Expression ◽

Comparative Genomics ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Normal Diet ◽

Specific Gene ◽

Whole Genome ◽

Metabolic Switch ◽

M1 Macrophages ◽

E Coli

ObjectiveThe gut microbiota is associated with nonalcoholic fatty liver disease (NAFLD). We isolated the Escherichia coli strain NF73-1 from the intestines of a NASH patient and then investigated its effect and underlying mechanism.Methods16S ribosomal RNA (16S rRNA) amplicon sequencing was used to detect bacterial profiles in healthy controls, NAFLD patients and NASH patients. Highly enriched E. coli strains were cultured and isolated from NASH patients. Whole-genome sequencing and comparative genomics were performed to investigate gene expression. Depending on the diet, male C57BL/6J mice were further grouped in normal diet (ND) and high-fat diet (HFD) groups. To avoid disturbing the bacterial microbiota, some of the ND and HFD mice were grouped as “bacteria-depleted” mice and treated with a cocktail of broad-spectrum antibiotic complex (ABX) from the 8th to 10th week. Then, E. coli NF73-1, the bacterial strain isolated from NASH patients, was administered transgastrically for 6 weeks to investigate its effect and mechanism in the pathogenic progression of NAFLD.ResultsThe relative abundance of Escherichia increased significantly in the mucosa of NAFLD patients, especially NASH patients. The results from whole-genome sequencing and comparative genomics showed a specific gene expression profile in E. coli strain NF73-1, which was isolated from the intestinal mucosa of NASH patients. E. coli NF73-1 accelerates NAFLD independently. Only in the HFD-NF73-1 and HFD-ABX-NF73-1 groups were EGFP-labeled E. coli NF73-1 detected in the liver and intestine. Subsequently, translocation of E. coli NF73-1 into the liver led to an increase in hepatic M1 macrophages via the TLR2/NLRP3 pathway. Hepatic M1 macrophages induced by E. coli NF73-1 activated mTOR-S6K1-SREBP-1/PPAR-α signaling, causing a metabolic switch from triglyceride oxidation toward triglyceride synthesis in NAFLD mice.ConclusionsE. coli NF73-1 is a critical trigger in the progression of NAFLD. E. coli NF73-1 might be a specific strain for NAFLD patients.

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Tracing Melioidosis Back to the Source: Using Whole-Genome Sequencing To Investigate an Outbreak Originating from a Contaminated Domestic Water Supply

Journal of Clinical Microbiology ◽

10.1128/jcm.03453-14 ◽

2015 ◽

Vol 53 (4) ◽

pp. 1144-1148 ◽

Cited By ~ 18

Author(s):

Evan McRobb ◽

Derek S. Sarovich ◽

Erin P. Price ◽

Mirjam Kaestli ◽

Mark Mayo ◽

...

Keyword(s):

Water Supply ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Clinical Isolates ◽

Whole Genome ◽

Northern Australia ◽

Source Attribution ◽

Environmental Strain ◽

Content Type ◽

Groundwater Supply

Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillusBurkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic.B. pseudomalleiis classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure.B. pseudomalleiisolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir ofB. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens.

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Evaluating whole-genome sequencing quality metrics for enteric pathogen outbreaks

PeerJ ◽

10.7717/peerj.12446 ◽

2021 ◽

Vol 9 ◽

pp. e12446

Author(s):

Darlene D. Wagner ◽

Heather A. Carleton ◽

Eija Trees ◽

Lee S. Katz

Keyword(s):

Whole Genome Sequencing ◽

Genome Sequencing ◽

Genome Assembly ◽

Enteric Bacteria ◽

Quality Metrics ◽

Read Length ◽

Snp Analysis ◽

Whole Genome ◽

Insert Size ◽

E Coli

Background Whole genome sequencing (WGS) has gained increasing importance in responses to enteric bacterial outbreaks. Common analysis procedures for WGS, single nucleotide polymorphisms (SNPs) and genome assembly, are highly dependent upon WGS data quality. Methods Raw, unprocessed WGS reads from Escherichia coli, Salmonella enterica, and Shigella sonnei outbreak clusters were characterized for four quality metrics: PHRED score, read length, library insert size, and ambiguous nucleotide composition. PHRED scores were strongly correlated with improved SNPs analysis results in E. coli and S. enterica clusters. Results Assembly quality showed only moderate correlations with PHRED scores and library insert size, and then only for Salmonella. To improve SNP analyses and assemblies, we compared seven read-healing pipelines to improve these four quality metrics and to see how well they improved SNP analysis and genome assembly. The most effective read healing pipelines for SNPs analysis incorporated quality-based trimming, fixed-width trimming, or both. The Lyve-SET SNPs pipeline showed a more marked improvement than the CFSAN SNP Pipeline, but the latter performed better on raw, unhealed reads. For genome assembly, SPAdes enabled significant improvements in healed E. coli reads only, while Skesa yielded no significant improvements on healed reads. Conclusions PHRED scores will continue to be a crucial quality metric albeit not of equal impact across all types of analyses for all enteric bacteria. While trimming-based read healing performed well for SNPs analyses, different read healing approaches are likely needed for genome assembly or other, emerging WGS analysis methodologies.

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Integrating Culture-based Antibiotic Resistance Profiles with Whole-genome Sequencing Data for 11,087 Clinical Isolates

Genomics Proteomics & Bioinformatics ◽

10.1016/j.gpb.2018.11.002 ◽

2019 ◽

Vol 17 (2) ◽

pp. 169-182 ◽

Cited By ~ 2

Author(s):

Valentina Galata ◽

Cédric C. Laczny ◽

Christina Backes ◽

Georg Hemmrich-Stanisak ◽

Susanne Schmolke ◽

...

Keyword(s):

Antibiotic Resistance ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Clinical Isolates ◽

Whole Genome Sequencing Data ◽

Whole Genome ◽

Sequencing Data

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Genomic Investigation into the Virulome, Pathogenicity, Stress Response Factors, Clonal Lineages, and Phylogenetic Relationship of Escherichia coli Strains Isolated from Meat Sources in Ghana

Genes ◽

10.3390/genes11121504 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1504

Author(s):

Frederick Adzitey ◽

Jonathan Asante ◽

Hezekiel M. Kumalo ◽

Rene B. Khan ◽

Anou M. Somboro ◽

...

Keyword(s):

Escherichia Coli ◽

Stress Response ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Whole Genome ◽

Response Factors ◽

Pathogenic Potential ◽

E Coli ◽

Relationship Of ◽

Sequence Types

Escherichia coli are among the most common foodborne pathogens associated with infections reported from meat sources. This study investigated the virulome, pathogenicity, stress response factors, clonal lineages, and the phylogenomic relationship of E. coli isolated from different meat sources in Ghana using whole-genome sequencing. Isolates were screened from five meat sources (beef, chevon, guinea fowl, local chicken, and mutton) and five areas (Aboabo, Central market, Nyorni, Victory cinema, and Tishegu) based in the Tamale Metropolis, Ghana. Following microbial identification, the E. coli strains were subjected to whole-genome sequencing. Comparative visualisation analyses showed different DNA synteny of the strains. The isolates consisted of diverse sequence types (STs) with the most common being ST155 (n = 3/14). Based Upon Related Sequence Types (eBURST) analyses of the study sequence types identified four similar clones, five single-locus variants, and two satellite clones (more distantly) with global curated E. coli STs. All the isolates possessed at least one restriction-modification (R-M) and CRISPR defence system. Further analysis revealed conserved stress response mechanisms (detoxification, osmotic, oxidative, and periplasmic stress) in the strains. Estimation of pathogenicity predicted a higher average probability score (Pscore ≈ 0.937), supporting their pathogenic potential to humans. Diverse virulence genes that were clonal-specific were identified. Phylogenomic tree analyses coupled with metadata insights depicted the high genetic diversity of the E. coli isolates with no correlation with their meat sources and areas. The findings of this bioinformatic analyses further our understanding of E. coli in meat sources and are broadly relevant to the design of contamination control strategies in meat retail settings in Ghana.

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