The contributions of multidrug resistant clones to the success of pandemic extra-intestinal Pathogenic Escherichia coli

Genomic Epidemiology of Pseudomonas aeruginosa Sequence Type 111

PURPOSE

Pseudomonas aeruginosa ST111 is a global multidrug resistant (MDR) high-risk clone and comprehensive data about its molecular epidemiology is limited in Canada. Comprehensive data about the evolution of ST111 clades is limited. We characterized a Canadian collection of ST111 causing bloodstream infections and investigated the genomic relationship between Canadian and global ST111.

MATERIAL AND METHODS

We used long and short read WGS to characterize Canadian ST111 (n = 10 from 2010-18). We performed phylogenetic analysis on a global collection of ST111 (n = 969) and investigated the evolutionary history of clades using BEAST.

RESULTS

ST111 belonged to 3 clades (A, B, C) and two subclades (C1, C2). ST111-A was the ancestral clade while clades B, C1 and C2 emerged during the 1700s and 1800s. ST111-C2 dominated the global ST111 population. Serotype switching from O4 to O12 and the acquisition of Tn21, gyrA_T83I, parC_S87L, In59 with blaVIM-2 and aacA29 over time, were important in the evolution of ST111-C2. The Calgary ST111 strains consisted of a diverse collection that belonged to ST111-A (O4), ST111-C1 (O4) and ST111-C2 (O12) with different transposon structures.

CONCLUSIONS

We provided details on the emergence and evolution of different ST111 clades over time and highlighted the roles of serotype switching and the acquisition of certain AMR determinants and transposon structures in the evolution of ST111-C2.

Klebsiella pneumoniae with carbapenemases: high prevalence of sequence type 307 with blaOXA181 in South African community hospitals

This study investigated the molecular characteristics of urinary carbapenemase-producing Klebsiella pneumoniae isolates (n = 194) in Gauteng, South Africa, using simple, cost-effective PCR methodologies. Extensively drug resistant (XDR) ST307 with blaOXA-181 on IncX3 plasmids was endemic in Gauteng community hospitals leaving limited options for treating in- and outpatient urinary tract infections. High-level ceftazidime/avibactam resistance was detected among isolates harbouring blaOXA-48-like including blaOXA-181. These findings highlighted the need for genomic methodologies suitable for lower- and middle-income countries to track XDR clones and plasmids in community hospitals. Such results will aid with treatment and stewardship strategies.

Clinical validation of loop-mediated isothermal amplification for the detection of Escherichia coli sequence type complex 131

The dissemination of Escherichia coli multidrug-resistant (MDR) STc131 is related to its persistence in the human gastrointestinal tract as efficient gut colonizers. Infection and prevention measures are the cornerstones for preventing STc131 spread. Oral decolonization therapies that target ST131 are being developed. There are no rapid methods available to identify STc131 in human specimens. A loop-mediated isothermal amplification (LAMP) assay (named LAMP-ST131) was developed for the detection of STc131 on well-characterized E. coli isolates and then compared to culture and PCR for urines and stool swabs. With E. coli isolates (n = 720), LAMP-ST131 had a sensitivity (sens) of 100% [95% confidence interval (C.I.) = 98.1-100%)] and a specificity (spec) of 98.9% (95% C.I. = 97.5-99.5%). On urines (n = 550), LAMP-ST131 had a sens of 97.6% (95% C.I. = 89.68-94.33%) and a spec of 92.3% (95% C.I. = 87.68-99.88%), while on stool swabs (n = 278), LAMP-ST131 had a sens of 100% (95% C.I. = 88.7-100%) and a spec of 83.9% (95% C.I. = 78.8-87.9%). LAMP-ST131 detected 10 (urines) and 100 (stool swabs) gene copies/μL. LAMP-ST131 accurately identified STc131 within E. coli isolates and human specimens. The implementation of LAMP-ST131 will aid genomic surveys, enable the rapid implementation of effective infection prevention measures, and identify patients suitable for ST131 decolonization therapies. Such approaches will curb the spread of STc131 and decrease incidence rates of global MDR E. coli infections.

IMPORTANCE

We developed an accurate non-culture-based loop-mediated isothermal amplification (LAMP) methodology for the detection of (sequence type) STc131 among Escherichia coli isolates and human specimens. The use of LAMP-ST131 for global genomic surveillance studies and to identify patients that are suitable for ST131 decolonization therapies will be important for decreasing multidrug-resistant E. coli infections across the globe.

Escherichia coli sequence type 410 with carbapenemases: a paradigm shift within E. coli toward multidrug resistance

Escherichia coli sequence type ST410 is an emerging carbapenemase-producing multidrug-resistant (MDR) high-risk One-Health clone with the potential to significantly increase carbapenem resistance among E. coli. ST410 belongs to two clades (ST410-A and ST410-B) and three subclades (ST410-B1, ST410-B2, and ST410-B3). After a fimH switch between clades ST410-A and ST410-B1, ST410-B2 and ST410-B3 subclades showed a stepwise progression toward developing MDR. (i) ST410-B2 initially acquired fluoroquinolone resistance (via homologous recombination) in the 1980s. (ii) ST410-B2 then obtained CMY-2, CTX-M-15, and OXA-181 genes on different plasmid platforms during the 1990s. (iii) This was followed by the chromosomal integration of blaCMY-2, fstl YRIN insertion, and ompC/ompF mutations during the 2000s to create the ST410-B3 subclade. (iv) An IncF plasmid "replacement" scenario happened when ST410-B2 transformed into ST410-B3: F36:31:A4:B1 plasmids were replaced by F1:A1:B49 plasmids (both containing blaCTX-M-15) followed by blaNDM-5 incorporation during the 2010s. User-friendly cost-effective methods for the rapid identification of ST410 isolates and clades are needed because limited data are available about the frequencies and global distribution of ST410 clades. Basic mechanistic, evolutionary, surveillance, and clinical studies are urgently required to investigate the success of ST410 (including the ability to acquire successive MDR determinants). Such information will aid with management and prevention strategies to curb the spread of carbapenem-resistant E. coli. The medical community can ill afford to ignore the spread of a global E. coli clone with the potential to end the carbapenem era.

CRISPR-Cas9-mediated IncF plasmid curing in extraintestinal pathogenic Escherichia coli

IMPORTANCE

Understanding the role of IncF plasmids in the success of drug-resistant bacteria has far-reaching implications for tackling antibiotic resistance. The study's use of a novel CRISPR-Cas9-mediated plasmid-curing system provides a precision tool for dissecting the specific impact of IncF plasmids on ExPEC clones, especially high-risk, multidrug-resistant strains like ST131, ST1193, and ST410. The study offers a crucial stepping stone for future research into understanding how these plasmids influence more complex aspects of bacterial behavior, such as cell invasion and in vivo fitness.

Antibiotic susceptibility of Escherichia coli isolated from neonates admitted to neonatal intensive care units across China from 2015 to 2020

Background

Escherichia coli is one of the most common pathogens causing neonatal infections. Recently, the incidence and drug resistance of E. coli have increased, posing a major threat to neonatal health. The aim of this study was to describe and analyze the antibiotic resistance and multilocus sequence typing (MLST) characteristics of E. coli derived from infants admitted to neonatal intensive care units (NICUs) across China.

Methods

In this study, 370 strains of E. coli from neonates were collected. E. coli isolated from these specimens were subjected to antimicrobial susceptibility testing (by broth microdilution method) and MLST.

Results

The overall resistance rate was 82.68%, with the highest rate of methicillin/sulfamethoxazole (55.68%) followed by cefotaxime (46.22%). Multiple resistance rate was 36.74%, 132 strains (35.68%) had extended-spectrum β-lactamase (ESBL) phenotype and 5 strains (1.35%) had insensitivity to the tested carbapenem antibiotics. The resistance of E. coli isolated from different pathogenicity and different sites of infections varied, strains derived from sputum were significantly more resistant to β-lactams and tetracyclines. Currently, the prevalence spectrum in NICUs was dominated by ST1193, ST95, ST73, ST69 and ST131 across China. And the multidrug resistance of ST410 was the most severe. ST410 had the highest resistance rate to cefotaxime (86.67%), and its most common multidrug resistance pattern was β-lactams + aminoglycosides + quinolones + tetracyclines + sulfonamides.

Conclusions

Substantial proportions of neonatal E. coli isolates were severely resistant to commonly administered antibiotics. MLST results can suggest the prevalent characteristics of antibiotic resistance in E. coli with different ST types.