Pandemic Uropathogenic Fluoroquinolone-resistant Escherichia coli Have Enhanced Ability to Persist in the Gut and Cause Bacteriuria in Healthy Women.

We report that fluoroquinolone-resistant Escherichia coli are found in feces of 8.8% of healthy women, with most bacteria belonging to pandemic multidrug-resistant ST131-H30R or ST1193 clonal groups. Moreover, these highly uropathogenic clonal groups demonstrate an especially prolonged gut persistence and high rate of bacteriuria without documented urinary tract infection.

Rapid and Extensive Expansion in the United States of a New Multidrug-resistant Escherichia coli Clonal Group, Sequence Type 1193.

We describe the rapid and ongoing emergence across multiple US cities of a new multidrug-resistant Escherichia coli clone-sequence type (ST) 1193-resistant to fluoroquinolones (100%), trimethoprim-sulfamethoxazole (55%), and tetracycline (53%). ST1193 is associated with younger adults (age <40 years) and currently comprises a quarter of fluoroquinolone-resistant clinical E. coli urine isolates.

Uropathogenic Escherichia coli Metabolite-Dependent Quiescence and Persistence May Explain Antibiotic Tolerance during Urinary Tract Infection.

In the present study, it is shown that although Escherichia coli CFT073, a human uropathogenic (UPEC) strain, grows in liquid glucose M9 minimal medium, it fails to grow on glucose M9 minimal medium agar plates seeded with ≤10(6) CFU. The cells on glucose plates appear to be in a "quiescent" state that can be prevented by various combinations of lysine, methionine, and tyrosine. Moreover, the quiescent state is characteristic of ~80% of E. coli phylogenetic group B2 multilocus sequence type 73 strains, as well as 22.5% of randomly selected UPEC strains isolated from community-acquired urinary tract infections in Denmark. In addition, E. coli CFT073 quiescence is not limited to glucose but occurs on agar plates containing a number of other sugars and acetate as sole carbon sources. It is also shown that a number of E. coli CFT073 mini-Tn5 metabolic mutants (gnd, gdhA, pykF, sdhA, and zwf) are nonquiescent on glucose M9 minimal agar plates and that quiescence requires a complete oxidative tricarboxylic acid (TCA) cycle. In addition, evidence is presented that, although E. coli CFT073 quiescence and persistence in the presence of ampicillin are alike in that both require a complete oxidative TCA cycle and each can be prevented by amino acids, E. coli CFT073 quiescence occurs in the presence or absence of a functional rpoS gene, whereas maximal persistence requires a nonfunctional rpoS. Our results suggest that interventions targeting specific central metabolic pathways may mitigate UPEC infections by interfering with quiescence and persistence. IMPORTANCE Recurrent urinary tract infections (UTIs) affect 10 to 40% of women. In up to 77% of those cases, the recurrent infections are caused by the same uropathogenic E. coli (UPEC) strain that caused the initial infection. Upon infection of urothelial transitional cells in the bladder, UPEC appear to enter a nongrowing quiescent intracellular state that is thought to serve as a reservoir responsible for recurrent UTIs. Here, we report that many UPEC strains enter a quiescent state when ≤10(6) CFU are seeded on glucose M9 minimal medium agar plates and show that mutations in several genes involved in central carbon metabolism prevent quiescence, as well as persistence, possibly identifying metabolic pathways involved in UPEC quiescence and persistence in vivo.

Rapid Identification of Rectal Multidrug-resistant Escherichia coli Before Transrectal Prostate Biopsy.

OBJECTIVE: To develop and evaluate a rapid multiplex-quantitative polymerase chain reaction (qPCR) to identify fecal carriers of multidrug-resistant extraintestinal pathogenic Escherichia coli (MDR-ExPEC) clonal groups. METHODS: Men presenting for transrectal prostate biopsy (TPB) at the San Diego Veterans Affairs Medical Center underwent rectal culture immediately before TPB. Rectal swabs were streaked onto ciprofloxacin-supplemented (4 mg/L) MacConkey agar plates, identified, and susceptibility tested. The same swab was sent to the University of Washington for qPCR test (EST200) targeting 2 major MDR-ExPEC clonal groups--ST131 and ST69--that combined were expected to represent majority of fluoroquinolone (FQ)- and trimethoprim-sulfamethoxazole-resistant E coli. We calculate test characteristics including the area under the receiver operative curve (AUC). RESULTS: We enrolled 104 men from 11/5/2013 to 6/10/2014. FQ-resistant E coli were cultured from 19.2% (20/104) of rectal swabs, and 26% (27/104) of all swabs were positive for EST200 by PCR. The test characteristics comparing the EST200 to the culture-based detection of FQ resistance were 75%, 86%, 94%, and 56%, respectively. The AUC was 0.84 for the EST200 to detect FQ resistance before TPB. CONCLUSION: Compared to the reference standard rectal culture, EST200 was able to detect majority of FQ-resistant E coli on rectal swabs before prostate biopsy.

Characteristics of Escherichia coli sequence type 131 isolates that produce extended-spectrum ß-lactamases: global distribution of the H30-Rx sublineage.

We designed a study to describe the characteristics of sequence type 131 (ST131) lineages, including the H30-Rx sublineage, among a global collection of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli isolates from 9 countries collected from 2000 to 2011. A total of 240 nonrepeat isolates from Canada, the United States, Brazil, the Netherlands, France, the United Arab Emirates (UAE), India, South Africa, and New Zealand were included. Established PCR, sequencing, and typing methods were used to define ST131 lineages, H30 and H30-Rx phylogenetic groups, gyrA and parC mutations, virotypes, and plasmid-mediated quinolone resistance determinants. The majority of the isolates produced CTX-M-15 with aac(6')-lb-cr, belonged to phylogenetic group B2, and were positive for the H30 lineage with the gyrA1AB and parC1aAB mutations. ST131 showed 15 distinct pulsotypes; 43% of the isolates belonged to four pulsotypes, with a global distribution. Seventy-five percent of the ST131 isolates belonged to H30-Rx; this sublineage was present in all the countries and was associated with multidrug resistance, blaCTX-M-15, aac(6')-lb-cr, and virotypes A and C. The H41 lineage was negative for the ST131 pabB allele-specific PCR. The multidrug-resistant H30-Rx sublineage poses an important public health threat due to its global distribution, association with virotype C, and high prevalence among ST131 isolates that produce CTX-M-15.