Infectious Disease

Adenovirus E1A is the first viral protein expressed during infection. E1A controls critical aspects of downstream viral gene expression and cell cycle deregulation, and its function is thought to be highly conserved among adenoviruses. Various bioinformatics analyses of E1A from 38 human adenoviruses of species D (HAdV-D), including likelihood clade model partitioning, provided highly significant evidence of divergence of HAdV-Ds into two distinct groups for the conserved region 3 (CR3), present only in the E1A 13S isoform. This variance within E1A 13S of HAdV-Ds was not found in any other human adenovirus (HAdV) species. By protein sequence and structural analysis, the zinc finger motif of E1A CR3, previously shown as critical for transcriptional activation, showed the greatest differences. Subsequent codon usage bias analysis revealed substantial divergence in E1A 13S between the two groups of HAdV-Ds, suggesting that these two sub-groups of HAdV-D evolved under different cellular conditions. Hence, HAdV-D E1A embodies a previously unappreciated evolutionary divergence among HAdVs.

Enterococcus faecalis are a major cause of nosocomial infection worldwide, and the spread of vancomycin resistant strains (VRE) limits treatment options. Tigecycline-resistant VRE began to be isolated from inpatients at a Brazilian hospital within months following the addition of tigecycline to the hospital formulary. This was found to be the result of a spread of an ST103 E. faecalis clone. Our objective was to identify the basis for tigecycline resistance in this lineage. The genomes of two closely related tigecycline-susceptible (MIC = 0.06 mg/L), and three representative tigecycline-resistant (MIC = 1 mg/L) ST103 isolates were sequenced and compared. Further, efforts were undertaken to recapitulate the emergence of resistant strains in vitro. The specific mutations identified in clinical isolates in several cases were within the same genes identified in laboratory-evolved strains. The contribution of various polymorphisms to the resistance phenotype was assessed by trans-complementation of the wild type or mutant alleles, by testing for differences in mRNA abundance, and/or by examining the phenotype of transposon insertion mutants. Among tigecycline-resistant clinical isolates, five genes contained non-synonymous mutations, including two genes known to be related to enterococcal tigecycline resistance (tetM and rpsJ). Finally, within the in vitro-selected resistant variants, mutation in the gene for a MarR-family response regulator was associated with tigecycline resistance. This study shows that E. faecalis mutates to attain tigecycline resistance through the complex interplay of multiple mechanisms, along multiple evolutionary trajectories.

The large GTPase dynamin 2 controls both endosomal fission and microtubule acetylation. Here we report that dynamin 2 alters microtubules and regulates the trafficking of human adenovirus type 37. Dynamin 2 knockdown by siRNA in infected cells resulted in accumulation of acetylated tubulin, repositioning of microtubule organizing centers (MTOCs) closer to cell nuclei, increased virus in the cytosol (with a compensatory decrease in endosomal virus), reduced proinflammatory cytokine induction, and increased binding of virus to the nucleoporin, Nup358. These events led to increased viral DNA nuclear entry and viral replication. Overexpression of dynamin 2 generated opposite effects. Therefore, dynamin 2 inhibits adenovirus replication and promotes innate immune responses by the infected cell. MTOC transposition in dynamin 2 knockdown promotes a closer association with nuclear pore complexes to facilitate viral DNA delivery. Dynamin 2 plays a key role in adenoviral trafficking and influences host responses to infection.

PURPOSE: To compare the rates of infectious endophthalmitis following intravitreal injection of ranibizumab using prefilled syringes vs conventional preparation. DESIGN: Multicenter retrospective cohort study. METHODS: All eyes receiving intravitreal injection of 0.5 mg ranibizumab for retinal vascular diseases at 10 retina practices across the United States (2016 to 2017) and Japan (2009 to 2017) were included. The total numbers of eyes and injections were determined from billing codes. Endophthalmitis cases were determined from billing records and evaluated with chart review. Primary outcome was the rate of postinjection acute endophthalmitis. Secondary outcomes were visual acuity and microbial spectrum. RESULTS: A total of 243 754 intravitreal 0.5 mg ranibizumab injections (165 347 conventional and 78 407 prefilled) were administered to 43 132 unique patients during the study period. In the conventional ranibizumab group, a total of 43 cases of suspected endophthalmitis occurred (0.026%; 1 in 3845 injections) and 22 cases of culture-positive endophthalmitis occurred (0.013%; 1 in 7516 injections). In the prefilled ranibizumab group, 12 cases of suspected endophthalmitis occurred (0.015%; 1 in 6534 injections) and 2 cases of culture-positive endophthalmitis occurred (0.0026%; 1 in 39 204 injections). Prefilled syringes were associated with a trend toward decreased risk of suspected endophthalmitis (odds ratio 0.59; 95% confidence interval 0.31-1.12; P = .10) and a statistically significant decreased risk of culture-positive endophthalmitis (odds ratio 0.19; 95% confidence interval 0.045-0.82; P = .025). Average logMAR vision loss at final follow-up was significantly worse for eyes that developed endophthalmitis from the conventional ranibizumab preparation compared to the prefilled syringe group (4.45 lines lost from baseline acuity vs 0.38 lines lost; P = .0062). Oral-associated flora was found in 27.3% (6/22) of conventional ranibizumab culture-positive endophthalmitis cases (3 cases of Streptococcus viridans, 3 cases of Enterococcus faecalis) compared to 0 cases in the prefilled ranibizumab group. CONCLUSION: In a large, multicenter, retrospective study the use of prefilled syringes during intravitreal injection of ranibizumab was associated with a reduced rate of culture-positive endophthalmitis, including from oral flora, as well as with improved visual acuity outcomes.

Lipopeptide daptomycin is a last-line cell-membrane-targeting antibiotic to treat multidrug-resistant Alarmingly, daptomycin-resistant isolates have emerged. The mechanisms underlying daptomycin resistance are diverse and share similarities with resistances to cationic antimicrobial peptides and other lipopeptides, but they remain to be fully elucidated. We selected mutants with increased resistance to daptomycin from a library of transposon insertions in sequent type 8 (ST8) HG003. Insertions conferring increased daptomycin resistance were localized to two genes, one coding for a hypothetical lipoprotein (SAOUHSC_00362, Dsp1), and the other for an alkaline shock protein (SAOUHSC_02441, Asp23). Markerless loss-of-function mutants were then generated for comparison. All transposon mutants and knockout strains exhibited increased daptomycin resistance compared to those of wild-type and complemented strains. Null and transposon insertion mutants also exhibited increased resistance to cationic antimicrobial peptides. Interestingly, the mutant also showed increased resistance to vancomycin, a cell-wall-targeting drug with a different mode of action. Null mutations in both and resulted in increased tolerance as reflected by reduced killing to both daptomycin and vancomycin, as well as an increased tolerance to surfactant (Triton X-100). Neither mutant exhibited increased resistance to lysostaphin, a cell-wall-targeting endopeptidase. These findings identified two genes core to the species that make previously uncharacterized contributions to antimicrobial resistance and tolerance in .

PURPOSE: To assess the hypothesis that fluorometholone 0.1% eye drops are safe and effective as adjunctive therapy for trachomatous trichiasis (TT) surgery; determining the most promising dose. DESIGN: Randomized, placebo-controlled, double-masked parallel dose-ranging clinical trial. METHODS: Patients undergoing upper lid TT surgery at a rural Ethiopian hospital were randomized to fluorometholone 0.1% twice daily for 4 weeks, 4 times daily for 4 weeks, 4 times daily for 8 weeks, or matching frequency placebo in a 3:1:3:1:3:1 ratio for 1 eye. Randomization was stratified by TT severity (1-4 vs ≥5 lashes touching the globe). Safety outcomes (intraocular pressure [IOP] elevation, cataract, and other dose-limiting toxicities) and postoperative TT incidence were assessed over 1 year. RESULTS: Subjects randomized were 39:13:39:13:38:13 in the respective groups, and 1 subject in the 8-weeks fluorometholone group was withdrawn. Of 154 subjects, 148 (96.1%) completed 1 year's follow-up. Among 76 eyes receiving fluorometholone 4 times daily, 1 developed IOP elevation ≥ 30 mm Hg (to 37 mm Hg) and 1 had an allergic reaction attributed to the study drug; each resolved upon drug cessation without sequelae. No cataract or other dose-limiting toxicity events occurred. Postoperative TT within 1 year occurred in 29.3% of placebo eyes vs 17.7%, 19.6%, and 23.2% among the respective fluorometholone groups (P = .29 comparing placebo vs all active treatments combined). CONCLUSIONS: The results suggest fluorometholone 0.1% is likely to be safe and efficacious to reduce postoperative TT following TT surgery, and 1 drop twice daily for 4 weeks is the most promising dose. Confirmation in a full-scale clinical trial is needed before programmatic implementation.

Microbial keratitis (MK) is a potentially blinding condition which must be treated emergently to preserve vision. Although long recognized as a significant cause of corneal blindness, our understanding of its true global scale, associated burden of disease, and etiological patterns remains somewhat limited. Current epidemiological data suggests that MK may be epidemic in parts of the world--particularly within South, South-East and East Asia--and may exceed two million cases per year world-wide. Etiological patterns vary between economically developed and developing countries, with bacterial predominance in the former and fungal predominance in the latter. The key to effective management lies in timely diagnosis; however, the current gold standard of stain and culture remains time consuming and often yields no clinically useful results. For this reason, there are attempts to develop highly sensitive and accurate molecular diagnostic tools to provide rapid diagnosis, inform treatment decision making, and minimize the threat of antimicrobial resistance. We provide an overview of these key areas and of avenues for further research toward the goal of more effectively addressing the problem of MK on both an individual and public health level.

The original publication of this article [1] was missing the below author that made contributions to the research and the published article.

Staphylococcus aureus is an important human pathogen that causes serious antibiotic-resistant infections. Its population structure is marked by the appearance and dissemination of successful lineages across different settings. To begin understanding the population structure of S. aureus causing ocular and otolaryngology infections, we characterized 262 isolates by antimicrobial sensitivity testing and multilocus sequence typing (MLST). Methicillin-resistant S. aureus were subjected to SCCmec typing and Panton-Valentine leukocidin (PVL) screening. Although we detected a high level of genetic diversity among methicillin-sensitive (MSSA) isolates, (63 sequence types-STs), the population was dominated by five lineages: ST30, ST5, ST8, ST15 and ST97. Resistance to penicillin, erythromycin and clindamycin was common among the major MSSA lineages, with fluctuations markedly impacted by genetic background. Isolates belonging to the predominant lineage, ST30, displayed high rates of resistance to penicillin (100%), erythromycin (71%), and clindamycin (63%). Overall, 21% of the isolates were methicillin-resistant (MRSA), with an apparent enrichment among otitis and orbital cellulitis isolates (>40%). MRSA isolates belonged to 14 STs grouped in 5 clonal complexes (CC), however, CC5 (56.1%) and CC8 (38.6%) dominated the population. Most CC5 strains were SCCmec type II, and resembled the hospital-adapted USA100 clone. CC8 strains were SCCmec type IV, and 86% were positive for the PVL toxin, common features of the community-acquired clone USA300. CC5 strains harboring a SCCmec type IV, typical for the USA800 clone, comprised 15.5% of the population. USA100 strains were highly resistant to clindamycin, erythromycin and levofloxacin (100%), while USA300 strains were frequently resistant to erythromycin (89%) but displayed lower rates of resistance to levofloxacin (39%) and clindamycin (17%). Our data demonstrate that the ocular and otolaryngology S. aureus populations are composed of strains that are commonly resistant to clinically relevant antibiotics, and are associated with the major epidemic clonal complexes of both community and hospital origins.

Objective: Otologic methicillin-resistant (MRSA) infection has historically been rare, but given the rise in community-acquired MRSA carriage and infection at other body sites, prevalence rates may be changing. The goal of this study was to determine the prevalence of MRSA in recent otologic cultures from patients with acute otitis externa (AOE). Study design: Retrospective review of an institutional microbiologic database. Methods: A retrospective analysis was performed on serial culture isolates taken from the ear at a quaternary care hospital from January 2014 to April 2016. The causative pathogen and antibiotic sensitivity was determined by culture isolation and end point mean inhibitory concentration (MIC) testing. Medical records were reviewed to document patient characteristics, chronicity of infection, symptomatology, and previous treatments. Results: Over the study period, 173 patients were diagnosed with AOE and underwent otologic cultures of the ear. Fifty-three (30.6%) of cultures grew (SA). Of SA infections, 15 (28.3%) were identified as MRSA. MRSA patients were typically older than patients with methicillin-sensitive SA (MSSA) (mean age 46.7 ± 17.9 29 ± 19.4,  = 0.003) and had more medical comorbidities (4 1.7,  = 0.001). Compared to patients with MSSA, patients with MRSA were significantly more likely to have had prior ototopical antibiotic exposure (37% 73%,  = 0.019). Conclusion: Contemporary ear culture isolates at quaternary care center show higher rates of MRSA compared to historical reports in the literature. Clinicians should consider ear cultures to identify MRSA AOE. Level of Evidence: IV.

Purpose: To report the resolution of a fluoroquinolone-resistant keratitis with use of a prosthetic replacement of the ocular surface ecosystem (PROSE) device for enhanced targeted delivery of moxifloxiacin. Observations: A 62-year-old female presented with a 3-day history of pain, photophobia, and declining vision in left eye. The patient had a 2-year history of binocular PROSE treatment for ocular chronic graft-vs-host disease (cGVHD). A corneal ulcer was diagnosed and treated with topical 0.5% moxifloxacin solution 6 times per day, with continued wear of the PROSE device. After 4 days, worsening symptoms led to an increase in application of moxifloxicin to every 2 hours while awake. The drug was administered by removal of the device, cleaning and replenishing the reservoir with sterile saline, and adding one drop of the drug to the reservoir prior to reinsertion. Four days later, the corneal surface was epithelialized with only small subepithelial infiltrate remaining. The corneal culture grew an isolate carrying multiple mutations in the topoisomerase genes. These mutations were correlated with varying levels of resistance to ciprofloxacin (256 μg/mL), levofloxacin (8 μg/mL), and moxifloxacin (16 μg/mL). Conclusions and Importance: Although the infecting strain exhibited resistance to fluoroquinolones, the infection resolved when moxifloxacin was combined with PROSE therapy. Frequent dosing to the PROSE reservoir is likely to increase fluoroquinolone bioavailability and may represent a valuable approach to overcome antibiotic resistance.

In 1955, Human adenovirus type 14 (HAdV-B14p) was firstly identified in a military trainee diagnosed as acute respiratory disease (ARD) in the Netherlands. Fifty years later, a genomic variant, HAdV-B14p1, re-emerged in the U.S. and caused large and fatal ARD outbreaks. Subsequently, more and more ARD outbreaks occurred in Canada, the UK, Ireland, and China, in both military and civil settings. To generate a tool for the efficient characterization of this new genomic variant, a full-length infectious genomic clone of HAdV-B14 was successfully constructed using one-step Gibson Assembly method in this study. Firstly, the full genome of HAdV-B14p1 strain GZ01, the first HAdV-B14 isolate in China, was assembled into pBR322 plasmid by Gibson Assembly. The pBRAdV14 plasmid, generated by Gibson Assembly, was analyzed and verified by PCR, restriction enzymes digestion and the sequencing. Secondly, viruses were rescued from pBRAdV14-transfected A549 cells. The integrity of the rescued viruses was identified by restriction enzyme analysis. The complete sequence of the infectious clone was further sequenced. No mutation was found in the infectious clone during the construction when compared with the parental virus and pBR322 sequences. The direct immunofluorescence assay indicated the expression of the hexon protein. Finally, typical virions were observed; the one-step growth curves further showed that the DNA replication and viral reproduction efficiency of pBRAd14 derived viruses was similar with that of wild-type HAdV-B14 strain. The successful construction of the replication-competent infectious clone of pBRAdV14 facilitates the development of vaccine and antiviral drugs against HAdV-B14, as well as provides a novel strategy for rapid construction of infectious viral clones for other large-genome DNA viruses.

is a common opportunistic pathogen that colonizes cephalic recording chambers (CRCs) of macaques used in cognitive neuroscience research. We previously characterized 15 strains isolated from macaques at the Massachusetts Institute of Technology (MIT) in 2011. The goal of this study was to examine how a 2014 protocol change prohibiting the use of antimicrobials within CRCs affected colonizing strains. We collected 20 isolates from 10 macaques between 2013 and 2017 for comparison to 4 isolates previously characterized in 2011 with respect to the sequence type (ST) distribution, antimicrobial resistance, biofilm formation, and changes in genes that might confer a survival advantage. ST4 and ST55 were predominant among the isolates characterized in 2011, whereas the less antimicrobial-resistant lineage ST48 emerged to dominance after 2013. Two macaques remained colonized by ST4 and ST55 strains for 5 and 4 years, respectively. While the antimicrobial resistance and virulence factors identified in these ST4 and ST55 strains remained relatively stable, we detected an increase in biofilm formation ability over time in both isolates. We also found that ST48 strains were typically robust biofilm formers, which could explain why this ST increased in prevalence. Finally, we identified mutations in the DNA mismatch repair genes and in separate ST55 and ST4 strains and confirmed that strains bearing these mutations displayed a hypermutator phenotype. The presence of a hypermutator phenotype may complicate future antimicrobial treatment for clinically relevant infections in macaques. is a common cause of health care-associated infections in humans, largely due to its ability to persist in the hospital environment, colonize patients, acquire antimicrobial resistance, and form biofilms. Understanding how enterococci evolve in health care settings provides insight into factors affecting enterococcal survival and persistence. Macaques used in neuroscience research have long-term cranial implants that, despite best practices, often become colonized by This provides a unique opportunity to noninvasively examine the evolution of enterococci on a long-term indwelling device. We collected strains from cephalic implants over a 7-year period and characterized the sequence type, antimicrobial resistance, virulence factors, biofilm production, and hypermutator phenotypes. Improved antimicrobial stewardship allowed a less-antimicrobial-resistant strain to predominate at the implant interface, potentially improving antimicrobial treatment outcomes if future clinical infections occur. Biofilm formation appears to play an important role in the persistence of the strains associated with these implants.

A tigecycline-susceptible (TGC-S) Sequence Type (ST) 5 clinical methicillin-resistant Staphylococcus aureus (MRSA) strain was cultured in escalating levels of tigecycline, yielding mutants eightfold more resistant. Their genomes were sequenced to identify genetic alterations, resulting in resistance. Alterations in rpsJ, commonly related to tigecycline resistance, were also investigated. Tigecycline resistance was mediated by loss-of-function mutations in the transcriptional repressor mepR, resulting in derepression of the efflux pump mepA. Increased levels of resistance were obtained by successive mutations in mepA itself. No alterations in RpsJ were observed in selected strains, but we observed a K57M substitution, previously correlated with resistance, among TGC-S clinical strains. Thus, the pathway to tigecycline resistance in CC5 MRSA in vitro appears to be derepression of mep operon as the result of mepR loss-of-function mutation, followed by alterations in MepA efflux pump. This shows that other evolutionary pathways, besides mutation of rpsJ, are available for evolving tigecycline resistance in CC5 MRSA.

The aim of the study was to review the distribution, current trends, and microbiological characteristics of bacterial pathogens isolated from dacryocystitis patients in China during the last 15 years.This is a retrospective multiple-center noncomparative case series. The medical records of 15,452 consecutive patients from 7 cities diagnosed as having dacryocystitis between 2002 and 2016 were reviewed. The patients' demographics, microbiological data, and antibiotic sensitivity were reviewed and analyzed.A total of 3344 lacrimal sac content cultures were taken (21.6%) during the study period. A pathogen was identified in 1996 samples (59.7%), with bacterial isolates accounting for 1902 of the positive cultures (95.3%). Gram-positive isolates, gram-negative isolates, and anaerobic bacteria were found in 1218 (61.0%), 607 (30.4%), and 285 (14.3%) samples, respectively. An increase in gram-positive isolates over the study duration was found (P = .003). The predominant isolates were coagulase negative Staphylococci (485, 25.5%), Staphylococcus aureus (186, 9.8%), Pseudomonas aeruginosa (184, 9.7%), and Haemophilus influenzae (152, 9.0%). There was a trend toward increasing resistance to erythromycin from 10.5% during the first 5 years of the study to 20.7% during the last 5 years (P < .001). Antimicrobial susceptibility testing showed that gatifloxacin was the most effective drug against most of gram-positive, gram-negative, and anaerobic bacteria.The microbial culture rate of dacryocystitis in China is low. There was an increase in the percentage of gram-positive bacteria over time. The sensitivity of gram-positive isolates to tested antibiotics is relatively low compared with that of gram-negative isolates. Our data show that the empiric use of fourth-generation fluoroquinolones in refractory dacryocystitis may be justified.