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.

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.

Population-based genomic surveillance of Pseudomonas aeruginosa causing bloodstream infections in a large Canadian health region.

PURPOSE: Population-based surveillance was undertaken to determine clinical factors, susceptibility patterns, and incidence rates (IR) of Pseudomonas aeruginosa causing bloodstream infections (BSIs) in a Canadian region (2010-2018). METHODS: We combined clinical data with genomics to characterize P. aeruginosa (BSIs) (n = 167) in a well-defined Canadian (Calgary) human population over a 9-year period (2010-2018). RESULTS: The annual population IR per 100,000 patient years increased from 3.4/100,000 in 2010 to 5.9/100,000 in 2018, with the highest IRs in elderly males from the hospital setting. Over a quarter of patients presented with febrile neutropenia, followed by urinary tract infections and pneumonia. Antimicrobial resistance (AMR) rates and determinants were rare. The P. aeruginosa population was polyclonal consisting of three dominant sequence types (STs), namely ST244, ST111, and ST17. Antimicrobial-susceptible ST244 was the most common clone and belonged to three clades (A, B, C). The ST244 IR/100,000 increased over time due to the expansion of clade C. Multidrug-resistant ST111 was the second most common clone and IR/100,000 decreased over time. ST111 belonged to three clades (A, B, C) with clade C containing blaVIM-2. Different serotypes were linked to various STs. The IR/100,000 of P. aeruginosa that belonged to serotypes O6 increased significantly over time. CONCLUSION: An effective multivalent vaccine consisting of five serotypes (O1, O3, O5, O6, O11) would confer protection to > 70% of Calgary residents with P. aeruginosa BSIs. This study has provided a unique perspective of the population dynamics over time of P. aeruginosa STs, clades, and serotypes responsible for BSIs.

Genomic Epidemiology of Global Carbapenemase-Producing Escherichia coli, 2015-2017.

We describe the global molecular epidemiology of 229 carbapenemase-producing Escherichia coli in 36 countries during 2015-2017. Common carbapenemases were oxacillinase (OXA) 181 (23%), New Delhi metallo-ß-lactamase (NDM) 5 (20%), OXA-48 (17%), Klebsiella pneumoniae carbapenemase 2 (15%), and NDM-1 (10%). We identified 5 dominant sequence types (STs); 4 were global (ST410, ST131, ST167, and ST405), and 1 (ST1284) was limited to Turkey. OXA-181 was frequent in Jordan (because of the ST410-B4/H24RxC subclade) and Turkey (because of ST1284). We found nearly identical IncX3-blaOXA-181 plasmids among 11 STs from 12 countries. NDM-5 was frequent in Egypt, Thailand (linked with ST410-B4/H24RxC and ST167-B subclades), and Vietnam (because of ST448). OXA-48 was common in Turkey (linked with ST11260). Global K. pneumoniae carbapenemases were linked with ST131 C1/H30 subclade and NDM-1 with various STs. The global carbapenemase E. coli population is dominated by diverse STs with different characteristics and varied geographic distributions, requiring ongoing genomic surveillance.

Escherichia coli ST1193: Following in the Footsteps of E. coli ST131.

Escherichia coli ST1193 is an emerging global multidrug (MDR) high-risk clone and an important cause of community-onset urinary and bloodstream infections. ST1193 is imitating E. coli ST131, the most successful MDR clone of all time. Both clones emerged in the early 1990s by acquiring quinolone resistance-determining region (QRDR) mutations, IncF plasmids, virulence factors, and type 1 pilus (fimH) recombination. They are the only MDR clones that are dominant among unselected E. coli populations. ST131 is the most frequent clone and ST1193 the second most frequent clone among fluoroquinolone/cephalosporin-resistant E. coli isolates. Both clones have played pivotal roles in the global spread of MDR E. coli. ST1193 originated from ST clonal complex 14 (STc14), is lactose nonfermenting, belongs to phylogenetic group B2, and contains the O type O75. Global ST1193 prevalence has been increasing since 2012, even replacing ST131 in certain regions. blaCTX-M genes are rapidly expanding among ST1193 isolates, a scenario that occurred with ST131 during the 2000s. A validated PCR will enable global surveys to determine the extent of ST1193 among One Health E. coli isolates. The rapid emergence of ST1193 is concerning and is adding to the public health burden of MDR E. coli clones. Basic mechanistic, evolutionary, surveillance, and clinical studies are urgently required to investigate the success of ST1193. Such information will aid with management and prevention strategies. The medical community can ill afford to ignore the spread of another global successful MDR high-risk E. coli clone, especially one that is following in the footsteps of E. coli ST131.

Acquisition of genomic elements were pivotal for the success of Escherichia coli ST410.

BACKGROUND: Escherichia coli ST410 is an emerging MDR clone linked to blaCTX-M-15 and blaOXA-181. Limited comprehensive data about the global distribution of ST410 clades and mobile genetic elements associated with different ß-lactamases are available. METHODS: Short- and long-read WGS were performed on a collection of ST410 producing carbapenemases (n = 45) obtained from 11 countries. The evolutionary history of global E. coli ST410 was also investigated. RESULTS: OXA-181 and NDM-5 were the most frequent carbapenemases and used different underlying strategies to ensure their successful association with ST410 clades. Our phylogenetic analysis of publicly available ST410 genomes amended the previously published ST410 B subclades: ST410-B1 is identical to B1/H24, ST410-B2 includes B2/H24R and B3/H24Rx, while ST410-B3 corresponds to B4/H24RxC. Long-read WGS identified the following genomic events that likely shaped the evolution of ST410-B3: (i) gyrA and parC mutations were acquired via homologous recombination events; (ii) chromosomal integration of blaCMY-2 among ST410-B3; (iii) the emergence of ST410-B3 from ST410-B2 was accompanied by the replacement of IncFII plasmids harbouring blaCTX-M-15 (i.e. F36:31:A4:B1 in ST410-B2 with F1:A1:B49 plasmids in ST410-B3); and (iv) the NDM-5 gene was integrated within F1:A1:B49 plasmids over time. CONCLUSIONS: The global ST410 population producing carbapenemases is dominated by the ST410-B2 and B3 subclades with varied geographical distribution that requires ongoing genomic surveillance. We provided an updated timeline of pivotal genomic events that have shaped the success of the ST410-B3 subclade.

Population-based surveillance of Enterobacter cloacae complex causing blood stream infections in a centralized Canadian region.

Active population-based surveillance determined clinical factors, susceptibility patterns, incidence rates (IR), and genomics among Enterobacter cloacae complex (n = 154) causing blood stream infections in a centralized Canadian region (2015-2017). The annual population IR was 1.2/100,000 (95% CI 0.9-16) in 2015, 1.4/100,000 (95% CI 1.1-1.9) in 2016, and 1.5/100,000 (95% CI 1.2-2.0) in 2017, affecting mainly elderly males with underlying comorbid conditions in the hospital setting. E. cloacae complex was dominated by polyclonal subspecies (i.e., E. hormaechei subsp. steigerwaltii, subsp. hoffmanni and subsp. xiangfangesis). Antimicrobial resistant determinants were rare. This study provided novel information about Enterobacter genomics in a well-defined human population.

Escherichia coli sequence type 73 bloodstream infections in a centralized Canadian region and their association with companion animals: an ecological study.

PURPOSE: Extraintestinal pathogenic E. coli (ExPEC) are important pathogens causing community-acquired infections in humans, including bloodstream infections (BSIs), and may also colonize and infect animals. Our aim was to investigate associations between incidence rates (IRs) of BSIs caused by ExPEC and number of dogs and cats in communities in Calgary. METHODS: We used a well-characterized collection of blood isolates (n = 685) from Calgary, Alberta, Canada (2016). We used a combination of a seven-single-nucleotide-polymorphism quantitative PCR to type ExPEC into sequence types (STs). Calgary census data were used to estimate IRs per city community, as well as to investigate associations between number of companion animals per community, as obtained from licensing data, and IR of BSIs caused by each dominant ST. RESULTS: From the 685 isolates available, ExPEC ST131 was most prevalent (21.3% of included isolates), followed by ST73 (13.7%), ST69 (8.2%), ST95 (6.7%), and ST1193 (5.3%), respectively. Incidence of BSIs caused by ExPECs among Calgary residents was 48.8 cases per 100,000 resident-years, whereas communities had on average of 1.7 companion animals per 10 residents. No association between the number of dogs and IR of BSIs caused by ExPECs was detected for any ST. Conversely, the incidence rate of BSIs caused by ST73 was 3.6 times higher (95%CI 1.3-9.99) for every increase of 1 cat per 10 habitants in communities. CONCLUSIONS: Number of cats per habitant was positively associated with the incidence of BSIs caused by ExPEC ST73.

Spatial distribution of Escherichia coli ST131 C subclades in a centralized Canadian urban region.

INTRODUCTION: Escherichia coli ST131 is the most common multidrug-resistant (MDR) E. coli clone causing bloodstream infections (BSIs) in Calgary. This study describes patient characteristics and spatial distribution of ST131 subclades C1 and C2 causing BSIs in Calgary. METHODS: E. coli from blood (n = 685) obtained in Calgary, Canada, (2016) were PCR screened for ST131 and positives (n = 141) underwent whole genome sequencing. Patient characteristics were analysed using Fisher's Exact/t-tests and spatial analysis was used to identify clusters. RESULTS: Overall, 21% of E. coli was identified as ST131 and clade C dominated the population. ST131-C2 was associated with blaCTX-M-15 and significantly more MDR than ST131-C1. The spatial distribution in Calgary showed that ST131-C1 was mainly present in long-term care (LTC) residents whereas ST131-C2 clustered in a specific North East (NE) Calgary sector comprising of six neighbourhoods without LTC centres. This NE sector has high immigration and travel rates from the Indian subcontinent. CONCLUSIONS: This study showed that ST131 C subclades have different geographical distribution patterns in Calgary. We believe that recent travel to and immigration from certain high-risk regions for antimicrobial resistance are responsible for the ST131-C2 NE Calgary clustering pattern.

Population-based epidemiology of Escherichia coli ST1193 causing blood stream infections in a centralized Canadian region.

Escherichia coli ST1193 is an emerging global clone associated with fluoroquinolone resistance. A population-based study described genomics, clinical factors, susceptibility patterns, and incidence rates of ST1193 (n = 69) causing incident blood stream infections in a centralized Canadian region 2016-18. ST1193 was responsible for community-acquired upper urinary tract infections among the elderly. The incidence rate (IR) per 100,000 person-years among Calgary residents increased from 1.0 (95%confidence interval [95%CI] 0.7-1.5) in 2016, to 1.7 (95%CI 1.3-2.3) in 2018 (p = 0.05). This was mainly due to the significant increase of ST1193 blood stream infections among female long-term care (LTC) residents. ST1193 IR with blaCTX-Ms was 3.18 times higher in 2018 than in 2016 (CI 95% 0.98-13.49). We identified a ST1193 isolate with only a parC S80I mutation that is different from previously published data. The population-based study identified a significant increase over a 2-year period of E. coli ST1193 blood stream infections among elderly females residing in LTC centers. There was also a notable increase of ST1193 with bla CTX-Ms in 2018. The rapid emergence of ST1193 is concerning and adding to the public health burden of multidrug resistant E. coli blood stream infections in Calgary.

The importance of Escherichia coli clonal complex 10 and ST131 among Tanzanian patients on antimicrobial resistance surveillance programs.

The objective of this study was to characterize antimicrobial resistance (AMR) of WHO priority 1 critical pathogen (extrapathogenic Escherichia coli (ExPEC), sequence types (STs), and ST131 clades from patients in Tanzania so as to guide specific antimicrobial therapies and preventive measures. A total of 143 ExPEC strains (128 from pregnant women with urinary tract infections and 15 from children with blood stream infections) were collected between March 2016 and October 2017. These were characterized into ST-fimH clones by a 7-single nucleotide polymorphism quantitative polymerase chain reaction (7-SNP qPCR) and gene sequencing, and to ST131 clades by multiplex PCR. The extended-spectrum beta-lactamases (ESBL) production was 16.1% (23/143), and was predominantly due to the blaCTX-M-15 (91.3%, n=21). ESBL production was significantly more among strains from children (53.3%) than pregnant women (11.7%) (OR (95%CI): 8.61 (2.73-27.15); p-value <0.001)). Approximately 61.5% (n=88) ExPEC were typed into their respective STs/CCs (87 by the 7-SNP qPCR and by an additional of one or two genes sequencing). The commonest STs/CCs among typeable strains were CC10 (28.4%, n=25), ST131 (18.2%, n=16), and ST38 (10.2%, n=9). The ST131 clades (C1 (4, 25.0%) and C2 (6, 37.5%)) were predominantly associated with fluoroquinolone resistance and ESBL production, respectively. Approximately 60.8% of ExPEC strains and all dominant clones were typed by the 7-SNP qPCR by additional sequencing. The multiplex clade PCR allowed linkage of the global clone ST131 with AMR phenotypes. These feasible and user-friendly molecular tools can be routinely used for surveillance programs in resource-limited settings.

Molecular epidemiology of extended-spectrum beta-lactamase-producing extra-intestinal pathogenic Escherichia coli strains over a 2-year period (2017-2019) from Zimbabwe.

This study was designed to characterize extended-spectrum beta-lactamase (ESBL)-producing extra-intestinal pathogenic Escherichia coli (E.coli) (ExPEC) associated with urinary tract infections in nine different geographic regions of Zimbabwe over a 2-year period (2017-2019). A total of 48 ESBL-positive isolates from urine specimen were selected for whole-genome sequencing from 1246 Escherichia coli isolates biobanked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Programme to provide representation of different geographical regions and year of isolation. The majority of ESBL E. coli isolates produced cefotaximase-Munich (CTX-M)-15, CTX-M-27, and CTX-M-14. In this study, sequence types (ST) 131 and ST410 were the most predominant antimicrobial-resistant clones and responsible for the increase in ESBL-producing E. coli strains since 2017. Novel ST131 complex strains were recorded during the period 2017 to 2018, thus showing the establishment and evolution of this antimicrobial-resistant ESBL clone in Zimbabwe posing an important public health threat. Incompatibility group F plasmids were predominant among ST131 and ST410 isolates with the following replicons recorded most frequently: F1:A2:B20 (9/19, 47%), F2:A1: B (5/19, 26%), and F1:A1:B49 (8/13, 62%). The results indicate the need for continuous tracking of different ESBL ExPEC clones on a global scale, while targeting specific STs (e.g. ST131 and ST410) through control programs will substantially decrease the spread of ESBLs among ExPEC.

The Global Ascendency of OXA-48-Type Carbapenemases.

Surveillance studies have shown that OXA-48-like carbapenemases are the most common carbapenemases in Enterobacterales in certain regions of the world and are being introduced on a regular basis into regions of nonendemicity, where they are responsible for nosocomial outbreaks. OXA-48, OXA-181, OXA-232, OXA-204, OXA-162, and OXA-244, in that order, are the most common enzymes identified among the OXA-48-like carbapenemase group. OXA-48 is associated with different Tn1999 variants on IncL plasmids and is endemic in North Africa and the Middle East. OXA-162 and OXA-244 are derivatives of OXA-48 and are present in Europe. OXA-181 and OXA-232 are associated with ISEcp1, Tn2013 on ColE2, and IncX3 types of plasmids and are endemic in the Indian subcontinent (e.g., India, Bangladesh, Pakistan, and Sri Lanka) and certain sub-Saharan African countries. Overall, clonal dissemination plays a minor role in the spread of OXA-48-like carbapenemases, but certain high-risk clones (e.g., Klebsiella pneumoniae sequence type 147 [ST147], ST307, ST15, and ST14 and Escherichia coli ST38 and ST410) have been associated with the global dispersion of OXA-48, OXA-181, OXA-232, and OXA-204. Chromosomal integration of blaOXA-48 within Tn6237 occurred among E. coli ST38 isolates, especially in the United Kingdom. The detection of Enterobacterales with OXA-48-like enzymes using phenotypic methods has improved recently but remains challenging for clinical laboratories in regions of nonendemicity. Identification of the specific type of OXA-48-like enzyme requires sequencing of the corresponding genes. Bacteria (especially K. pneumoniae and E. coli) with blaOXA-48, blaOXA-181, and blaOXA-232 are emerging in different parts of the world and are most likely underreported due to problems with the laboratory detection of these enzymes. The medical community should be aware of the looming threat that is posed by bacteria with OXA-48-like carbapenemases.

Trends in Population Dynamics of Escherichia coli Sequence Type 131, Calgary, Alberta, Canada, 2006-20161.

Global expansion of antimicrobial drug-resistant Escherichia coli sequence type (ST) 131 is unrivaled among human bacteria. Understanding trends among ST131 clades will help with designing prevention strategies. We screened E. coli from blood samples (n = 1,784) obtained in Calgary, Alberta, Canada, during 2006, 2012, and 2016 by PCR for ST131 and positive samples (n = 344) underwent whole-genome sequencing. The incidence rate per 100,000 residents increased from 4.91 during 2006 to 12.35 during 2012 and 10.12 during 2016. ST131 belonged to clades A (10%), B (9%), and C (81%). Clades C1-nonM27 and B were common during 2006, and C2 containing blaCTX-M-15, C1-M27 containing blaCTX-M-27, and A were responsible for the increase of ST131 during 2012 and 2016. C2 was the most antimicrobial drug-resistant subclade and increased exponentially over time. Eradicating ST131, more specifically the C2 subclade, will lead to considerable public health benefits for persons in Calgary.

Emerging Antimicrobial-Resistant High-Risk Klebsiella pneumoniae Clones ST307 and ST147.

There is an enormous global public health burden due to antimicrobial-resistant (AMR) Klebsiella pneumoniae high-risk clones. K. pneumoniae ST307 and ST147 are recent additions to the family of successful clones in the species. Both clones likely emerged in Europe during the early to mid-1990s and, in a relatively short time, became prominent global pathogens, spreading to all continents (with the exception of Antarctica). ST307 and ST147 consist of multiple clades/clusters and are associated with various carbapenemases (i.e., KPCs, NDMs, OXA-48-like, and VIMs). ST307 is endemic in Italy, Colombia, the United States (Texas), and South Africa, while ST147 is endemic in India, Italy, Greece, and certain North African countries. Both clones have been introduced into regions of nonendemicity, leading to worldwide nosocomial outbreaks. Genomic studies showed ST307 and ST147 contain identical gyrA and parC mutations and likely obtained plasmids with blaCTX-M-15 during the early to mid-2000s, which aided in their global distribution. ST307 and ST147 then acquired plasmids with various carbapenemases during the late 2000s, establishing themselves as important AMR pathogens in certain regions. Both clones are likely underreported due to restricted detection methodologies. ST307 and ST147 have the ability to become major threats to public health due to their worldwide distribution, ability to cause serious infections, and association with AMR, including panresistance. The medical community at large, especially those concerned with antimicrobial resistance, should be aware of the looming threat posed by emerging AMR high-risk clones such as K. pneumoniae ST307 and ST147.

A Comprehensive Account of Escherichia coli Sequence Type 131 in Wastewater Reveals an Abundance of Fluoroquinolone-Resistant Clade A Strains.

In the ten years since its discovery, the Escherichia coli clone sequence type 131 (ST131) has become a major international health threat, with the multidrug-resistant and extended-spectrum ß-lactamase (ESBL)-producing clade C emerging as the globally dominant form. ST131 has previously been isolated from wastewater; however, most of these studies selectively screened for ESBL-producing organisms, thereby missing the majority of remaining ST131 clades. In this study, we used a high-throughput PCR-based screening strategy to comprehensively examine wastewater for the presence of ST131 over a 1-year period. Additional multiplex PCRs were used to differentiate clades and obtain an unbiased account of the total ST131 population structure within the collection. Furthermore, antimicrobial susceptibility profiles of all ST131-positive samples were tested against a range of commonly used antibiotics. From a total of over 3,762 E. coli wastewater samples, 1.86% (n = 70) tested positive for ST131, with the majority being clade A isolates. In total, 63% (n = 44) were clade A, 29% (n = 20) were clade B, 1% (n = 1) were clade C0, 6% (n = 4) were clade C1, and 1% (n = 1) were clade C2. In addition, a very high rate of resistance to commonly used antibiotics among wastewater isolates is reported, with 72.7% (n = 32) of clade A resistant to ciprofloxacin and high rates of resistance to gentamicin, sulfamethoxazole-trimethoprim, and tetracycline in clades that are typically sensitive to antibiotics.IMPORTANCE ST131 is a global pathogen. This clone causes urinary tract infections and is frequently isolated from human sources. However, little is known about ST131 from environmental sources. With the widely reported increase in antibiotic concentrations found in wastewater, there is additional selection pressure for the emergence of antibiotic-resistant ST131 in this niche. The unbiased screening approach reported herein revealed that previously antibiotic-sensitive lineages of ST131 are now resistant to commonly used antibiotics present in wastewater systems and may be capable of surviving UV sterilization. This is the most comprehensive account of ST131 in the wastewater niche to date and an important step in better understanding the ecology of this global pathogen.

Klebsiella pneumoniae ST307 with blaOXA-181, South Africa, 2014-2016.

Klebsiella pneumoniae sequence type (ST) 307 is an emerging global antimicrobial drug-resistant clone. We used whole-genome sequencing and PCR to characterize K. pneumoniae ST307 with oxacillinase (OXA) 181 carbapenemase across several private hospitals in South Africa during 2014-2016. The South Africa ST307 belonged to a different clade (clade VI) with unique genomic characteristics when compared with global ST307 (clades I-V). Bayesian evolution analysis showed that clade VI emerged around March 2013 in Gauteng Province, South Africa, and then evolved during 2014 into 2 distinct lineages. K. pneumoniae ST307 clade VI with OXA-181 disseminated over a 15-month period within 42 hospitals in 23 cities across 6 northeastern provinces, affecting 350 patients. The rapid expansion of ST307 was most likely due to intrahospital, interhospital, intercity, and interprovince movements of patients. This study highlights the importance of molecular surveillance for tracking emerging antimicrobial clones.

Genomic and Functional Analysis of Emerging Virulent and Multidrug-Resistant Escherichia coli Lineage Sequence Type 648.

The pathogenic extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli lineage ST648 is increasingly reported from multiple origins. Our study of a large and global ST648 collection from various hosts (87 whole-genome sequences) combining core and accessory genomics with functional analyses and in vivo experiments suggests that ST648 is a nascent and generalist lineage, lacking clear phylogeographic and host association signals. By including large numbers of ST131 (n = 107) and ST10 (n = 96) strains for comparative genomics and phenotypic analysis, we demonstrate that the combination of multidrug resistance and high-level virulence are the hallmarks of ST648, similar to international high-risk clonal lineage ST131. Specifically, our in silico, in vitro, and in vivo results demonstrate that ST648 is well equipped with biofilm-associated features, while ST131 shows sophisticated signatures indicative of adaption to urinary tract infection, potentially conveying individual ecological niche adaptation. In addition, we used a recently developed NFDS (negative frequency-dependent selection) population model suggesting that ST648 will increase significantly in frequency as a cause of bacteremia within the next few years. Also, ESBL plasmids impacting biofilm formation aided in shaping and maintaining ST648 strains to successfully emerge worldwide across different ecologies. Our study contributes to understanding what factors drive the evolution and spread of emerging international high-risk clonal lineages.

A Cost-Effective Method for Identifying Enterobacterales with OXA-181.

OXA-181 is the second most common global OXA-48-like carbapenemase and is endemic in the Indian subcontinent. Molecular studies have shown that Enterobacterales with OXA-181 are often introduced into regions of nonendemicity. Distinguishing OXA-181 from other OXA-48-like enzymes often requires sequencing, which is rather expensive and time-consuming. A specific PCR (i.e., OXA181PCR) for the detection of blaOXA-181 was validated using a global collection (n = 315) of bacteria with well-characterized carbapenemases and showed 100% sensitivity and specificity (95% confidence interval [CI], 94.1 to 100 and 98.6 to 100, respectively) for detecting bacteria with OXA-181. The OXA181PCR subsequently gave positive results on 58/160 (36%) Enterobacterales with OXA-48-like carbapenemases from the 2015 INFORM surveillance program. The blaOXA-181-positive Enterobacterales were present in 9 countries spanning 5 continents, illustrating the global distribution of OXA-181. This methodology can easily be incorporated into molecular surveillance programs to provide accurate information about the prevalence of OXA-181. A loop-mediated isothermal amplification (LAMP)-OXA48 assay overall performed well for detecting OXA-48-like enzymes but showed poor specificity due to false-positive results with non-OXA carbapenemases.

Molecular Diagnosis of Vaginitis: Comparing Quantitative PCR and Microbiome Profiling Approaches to Current Microscopy Scoring.

Vaginitis is often diagnosed by microscopy and limited to testing for bacterial vaginosis (BV), vulvovaginal candidiasis, and trichomoniasis. Approximately 10% of vaginal swabs are negative but designated "altered flora" by BV Nugent score, leaving clinicians unsure how to treat patients. Accurate and comprehensive vaginitis diagnostics are needed to direct treatment and reduce risks of recurrent or more severe infections. Vaginal swabs were collected from 93 women (mean age, 23.53 years; range, 18 to 42 years) in a cross-sectional study. Microscopy results for BV and Candida were compared to those from two molecular approaches: (i) a comprehensive quantitative PCR (qPCR) assay, including testing for aerobic vaginitis (AV), Candida, sexually transmitted infections (STI), and BV (Applied Biosystems) with an accompanying BV interpretive algorithm (Coriell Life Sciences), and (ii) microbiome profiling of the 16S rRNA gene (Illumina). Microscopy plus BV Nugent score had 76% overall agreement with the qPCR plus BV interpretive algorithm method (24 positive, 47 negative). OF the nine samples designated altered flora by Nugent, five were categorized BV positive and four were BV negative by the qPCR method. Although BV negative, 3/4 of the latter samples had positive AV targets with one also was STI positive. Microscopic identification of Candida versus that by qPCR had 94% agreement (9 positive, 78 negative). The comprehensive qPCR assay revealed alternative etiologies summarized as 38% BV, 10% AV, 5% Candida, 2% STI, 10% mixed infection (positive targets in multiple panels), and 35% negative for all targets. 16S microbiome analysis confirmed the bacterial qPCR results and identified differentiating patterns between AV, BV, and Lactobacillus-dominated vaginal microbiomes.