Household transmission of carbapenemase-producing Enterobacteriaceae: a prospective cohort study.

OBJECTIVES: To estimate the transmission rate of carbapenemase-producing Enterobacteriaceae (CPE) in households with recently hospitalized CPE carriers. METHODS: We conducted a prospective case-ascertained cohort study. We identified the presence of CPE in stool samples from index subjects, household contacts and companion animals and environmental samples at regular intervals. Linked transmissions were identified by WGS. A Markov model was constructed to estimate the household transmission potential of CPE. RESULTS: Ten recently hospitalized index patients and 14 household contacts were included. There were seven households with one contact, two households with two contacts, and one household with three contacts. Index patients were colonized with blaOXA-48-like (n = 4), blaKPC-2 (n = 3), blaIMP (n = 2), and blaNDM-1 (n = 1), distributed among divergent species of Enterobacteriaceae. After a cumulative follow-up time of 9.0 years, three family members (21.4%, 3/14) acquired four different types of CPE in the community (hazard rate of 0.22/year). The probability of CPE transmission from an index patient to a household contact was 10% (95% CI 4%-26%). CONCLUSIONS: We observed limited transmission of CPE from an index patient to household contacts. Larger studies are needed to understand the factors associated with household transmission of CPE and identify preventive strategies.

Duration of Carbapenemase-Producing Enterobacteriaceae Carriage in Hospital Patients.

To determine the duration of carbapenemase-producing Enterobacteriaceae (CPE) carriage, we studied 21 CPE carriers for ¼1 year. Mean carriage duration was 86 days; probability of decolonization in 1 year was 98.5%, suggesting that CPE-carriers' status can be reviewed yearly. Prolonged carriage was associated with use of antimicrobial drugs.

Intracellular Uropathogenic E. coli Exploits Host Rab35 for Iron Acquisition and Survival within Urinary Bladder Cells.

Recurrent urinary tract infections (UTIs) caused by uropathogenic E. coli (UPEC) are common and morbid infections with limited therapeutic options. Previous studies have demonstrated that persistent intracellular infection of bladder epithelial cells (BEC) by UPEC contributes to recurrent UTI in mouse models of infection. However, the mechanisms employed by UPEC to survive within BEC are incompletely understood. In this study we aimed to understand the role of host vesicular trafficking proteins in the intracellular survival of UPEC. Using a cell culture model of intracellular UPEC infection, we found that the small GTPase Rab35 facilitates UPEC survival in UPEC-containing vacuoles (UCV) within BEC. Rab35 plays a role in endosomal recycling of transferrin receptor (TfR), the key protein responsible for transferrin-mediated cellular iron uptake. UPEC enhance the expression of both Rab35 and TfR and recruit these proteins to the UCV, thereby supplying UPEC with the essential nutrient iron. Accordingly, Rab35 or TfR depleted cells showed significantly lower intracellular iron levels and reduced ability to support UPEC survival. In the absence of Rab35, UPEC are preferentially trafficked to degradative lysosomes and killed. Furthermore, in an in vivo murine model of persistent intracellular infection, Rab35 also colocalizes with intracellular UPEC. We propose a model in which UPEC subverts two different vesicular trafficking pathways (endosomal recycling and degradative lysosomal fusion) by modulating Rab35, thereby simultaneously enhancing iron acquisition and avoiding lysosomal degradation of the UCV within bladder epithelial cells. Our findings reveal a novel survival mechanism of intracellular UPEC and suggest a potential avenue for therapeutic intervention against recurrent UTI.

Sequencing of E. coli strain UTI89 on multiple sequencing platforms.

OBJECTIVES: The availability of matched sequencing data for the same sample across different sequencing platforms is a necessity for validation and effective comparison of sequencing platforms. A commonly sequenced sample is the lab-adapted MG1655 strain of Escherichia coli; however, this strain is not fully representative of more complex and dynamic genomes of pathogenic E. coli strains. DATA DESCRIPTION: We present six new sequencing data sets for another E. coli strain, UTI89, which is an extraintestinal pathogenic strain isolated from a patient suffering from a urinary tract infection. We now provide matched whole genome sequencing data generated using the PacBio RSII, Oxford Nanopore MinION R9.4, Ion Torrent, ABI SOLiD, and Illumina NextSeq sequencers. Together with other publically available datasets, UTI89 has a nearly complete suite of data generated on most second- and third-generation sequencers. These data can be used as an additional validation set for new sequencing technologies and analytical methods. More than being another E. coli strain, however, UTI89 is pathogenic, with a 10% larger genome, additional pathogenicity islands, and a large plasmid, features that are common among other naturally occurring and disease-causing E. coli isolates. These data therefore provide a more medically relevant test set for development of algorithms.

Complete Genome Sequence of Photobacterium leiognathi Strain JS01.

Photobacterium leiognathi is a bioluminescent symbiont of fish of the Leiognathidae family. Here, we present the full-genome sequence of P. leiognathi strain JS01, a strain isolated from a nonluminescent Loligo sp. squid of Singaporean origin. No finished genome sequence of this species is currently publicly available.

A cross-sectional observational study of pneumococcal carriage in children, their parents, and older adults following the introduction of the 7-valent pneumococcal conjugate vaccine.

Using nasopharyngeal carriage as a marker of vaccine impact, pneumococcal colonization and its relation to invasive disease were examined in children, their parents, and older adults in the United Kingdom following introduction of 7-valent pneumococcal conjugate vaccine (PCV7) and prior to 13-valent pneumococcal conjugate vaccine (PCV13).A cross-sectional observational study was conducted, collecting nasopharyngeal swabs from children aged 25 to 55 months who had previously received 3 doses of PCV7, their parents, and adults aged ≥65 years. Pneumococcal serotyping was conducted according to World Health Organization guidelines with nontypeable isolates further analyzed by molecular serotyping. A national invasive disease surveillance program was conducted throughout the corresponding period.Pneumococcus was isolated from 47% of children, 9% of parents, and 2.2% of older adults. For these groups, the percentage of serotypes covered by PCV7 were 1.5%, 0.0%, and 15.4%, with a further 20.1%, 44.4%, and 7.7% coverage added by those in PCV13. In each group, the percentage of disease due to serotypes covered by PCV7 were 1.0%, 7.4% and 5.1% with a further 65.3%, 42.1%, and 61.4% attributed to those in PCV13.The prevalence of carriage is the highest in children, with direct vaccine impact exemplified by low carriage and disease prevalence of PCV7 serotypes in vaccinated children, whereas the indirect effects of herd protection are implied by similar observations in unvaccinated parents and older adults.