The Effect of Preoperative Chlorhexidine Gluconate Cleanse on Lower Extremity Surgical Site Infections: A Retrospective Cohort Study.

BACKGROUND: Lower extremity surgical sites are at an increased risk of wound infection following Mohs micrographic surgery. OBJECTIVE: To evaluate the rate of lower extremity surgical site infections following a 14-day regimen of preoperative 4% chlorhexidine gluconate (CHG) rinses and postoperative wound occlusion for 14 days. MATERIALS AND METHODS: Retrospective data were collected from procedures performed by the senior author from January 2022 through June 2023. To meet inclusion, patients must have completed waist-down CHG soak and rinse for 14 days before surgery, including the day before surgery. In addition, the patient must have kept the dressing clean, dry, and intact until the postoperative appointment at 14 days. RESULTS: A total of 100 Mohs cases met inclusion criteria. Zero patients developed a surgical site infection. CONCLUSION: Chlorhexidine gluconate preoperative rinsing and postoperative occlusion for 14 days may minimize the risk of wound infection. Although further research is indicated, an opportunity exists for the adoption of CHG into routine clinical practice in the outpatient dermatology setting.

The Host-Pathogen Interplay: A Tale of Two Stories within the Cornea and Posterior Segment.

Ocular infectious diseases are an important cause of potentially preventable vision loss and blindness. In the following manuscript, we will review ocular immunology and the pathogenesis of herpesviruses and Pseudomonas aeruginosa infections of the cornea and posterior segment. We will highlight areas of future research and what is currently known to promote bench-to-bedside discoveries to improve clinical outcomes of these debilitating ocular diseases.

Stability Characterization of the Novel Anti-Cancer HM-10/10 HDL-Mimetic Peptide.

Epithelial adenocarcinoma of the ovary and colon are associated with the highest rates of cancer-related deaths in women in the U.S. The literature supports the role of HDL-associated apolipoproteins in the treatment of cancer and other pro-inflammatory diseases. Previously, we developed a novel 20-amino acid mimetic peptide, HM-10/10, which potently inhibits tumor development and growth in colon and ovarian cancer. Here, we report the properties of HM-10/10 relative to its stability in vitro. The results demonstrated that HM-10/10 had the highest half-life in human plasma compared to plasma from other species tested. HM-10/10 demonstrated stability in human plasma and simulated gastric environment, increasing its promise as an oral pharmaceutical. However, under conditions modeling the small intestine, HM-10/10 demonstrated significant degradation, likely due to the peptidases encountered therein. Furthermore, HM-10/10 demonstrated no evidence of time-dependent drug-drug interactions, although it demonstrated CYP450 induction slightly above cutoff. As proteolytic degradation is a common limitation of peptide-based therapeutics, we are pursuing strategies to improve the stability properties of HM-10/10 by extending its bioavailability while retaining its low toxicity profile. HM-10/10 holds promise as a new agent to address the international women's health crisis of epithelial carcinomas of the ovary and colon.

Differentiation of Francisella tularensis Subspecies and Subtypes.

The highly infectious and zoonotic pathogen Francisella tularensis is the etiologic agent of tularemia, a potentially fatal disease if untreated. Despite the high average nucleotide identity, which is >99.2% for the virulent subspecies and >98% for all four subspecies, including the opportunistic microbe Francisella tularensis subsp. novicida, there are considerable differences in genetic organization. These chromosomal disparities contribute to the substantial differences in virulence observed between the various F. tularensis subspecies and subtypes. The methods currently available to genotype F. tularensis cannot conclusively identify the associated subpopulation without using time-consuming testing or complex scoring matrices. To address this need, we developed both single and multiplex quantitative real-time PCR (qPCR) assays that can accurately detect and identify the hypervirulent F. tularensis subsp. tularensis subtype A.I, the virulent F. tularensis subsp. tularensis subtype A.II, F. tularensis subsp. holarctica (also referred to as type B), and F. tularensis subsp. mediasiatica, as well as opportunistic F. tularensis subsp. novicida from each other and near neighbors, such as Francisella philomiragia, Francisella persica, and Francisella-like endosymbionts found in ticks. These fluorescence-based singleplex and non-matrix scoring multiplex qPCR assays utilize a hydrolysis probe, providing sensitive and specific F. tularensis subspecies and subtype identification in a rapid manner. Furthermore, sequencing of the amplified F. tularensis targets provides clade confirmation and informative strain-specific details. Application of these qPCR- and sequencing-based detection assays will provide an improved capability for molecular typing and clinical diagnostics, as well as facilitate the accurate identification and differentiation of F. tularensis subpopulations during epidemiological investigations of tularemia source outbreaks.

rs11670527 Upstream of ZNF264 Associated with Body Mass Index in the Coriell Personalized Medicine Collaborative.

INTRODUCTION: the effects of obesity on health are a concern for the military as they affect the fitness to serve of active service members, increase costs to the Military Health System, and reduce quality of life for veterans and beneficiaries. Although obesity can be influenced by behavioral and environmental factors, it has also been shown to be associated with genetic risk factors that are not fully understood. MATERIALS AND METHODS: we performed a genome-wide association study of 5,251 participants in the Coriell Personalized Medicine Collaborative, which includes 2,111 Air Force participants. We applied a generalized linear model, using principal component analysis to account for population structure, and analyzed single-variant associations with body mass index (BMI) as a continuous variable, using a Bonferroni-corrected P-value threshold to account for multiplicity. RESULTS: we identified one genome-wide significant locus, rs11670527, upstream of the ZNF264 gene on chromosome 19, associated with BMI. CONCLUSIONS: the finding of an association between rs11670527 and BMI adds to the growing body of literature characterizing the complex genetics of obesity. These efforts may eventually inform personalized interventions aimed at achieving and maintaining healthy weight.

Individuals with CYP2C8 and CYP2C9 reduced metabolism haplotypes self-adjusted ibuprofen dose in the Coriell Personalized Medicine Collaborative.

OBJECTIVES: The objectives of this study were to determine whether differences in CYP2C8 and CYP2C9 haplotype influence the dose of ibuprofen self-administered by individuals, and to examine the potential relationship between CYP2C8 and CYP2C9 reduced metabolism haplotypes and adverse events. PARTICIPANTS AND METHODS: We investigated relationships between genetic variations in CYP2C8 and CYP2C9 and ibuprofen use, dose, and side effects (reported by questionnaire) in 445 participants from the Coriell Personalized Medicine Collaborative. RESULTS: Carriers of reduced metabolism haplotypes for CYP2C8 (*2, *3, *4) and CYP2C9 (*2, *3) were significantly (P=0.0171) more likely than those lacking these variants to take less than the recommended dose of ibuprofen, after controlling for sex, age, race, and cohort. In contrast to ibuprofen dose, there were no differences in ibuprofen use frequency or reported side effects based on haplotype. However, there are often no early signs of acute kidney injury, the most serious side effect of elevated ibuprofen exposure. CONCLUSION: These results suggest a subset of individuals with genetic variation in CYP2C8 and CYP2C9 recognize that they obtain adequate drug efficacy with lower ibuprofen doses, or take lower doses due to prior side effects. However, most (82.6%) individuals with reduced metabolism haplotypes nonetheless took recommended or higher doses, potentially putting them at increased risk for side effects.

Precision Military Medicine: Conducting a multi-site clinical utility study of genomic and lifestyle risk factors in the United States Air Force.

Following several years enrolling disease-specific and otherwise healthy cohorts into the Coriell Personalized Medicine Collaborative, a prospective study aimed at evaluating the clinical utility of personal genomic information for common complex disease and pharmacogenomics, the Coriell Personalized Medicine Collaborative expanded to create a military cohort, specifically, the United States Air Force. Initial recruitment focused on Air Force Medical Service personnel and later expanded to include all Active Duty Air Force members and beneficiaries. Now in its 6th year, the study has produced a wide variety of insights, including optimal study design for military-sponsored genomic research, and discussion on genetic information sharing between and amongst Air Force study participants, civilian and military researchers, and the United States Department of Defense. Over the longer term, analyses will further contribute to the development of policies and processes relevant to clinical decision support and data sharing within the US military, and on-going work with the Air Force Medical Service sub-cohort will generate critical insights into how best to deploy useful genomic information in clinical care. Here we discuss challenges faced and critical success factors for military-civilian collaborations around genomic research.

Disseminated vaccine-strain varicella as initial presentation of the acquired immunodeficiency syndrome: a case report and review of the literature.

Varicella-zoster virus (VZV) infections have declined in many industrialized countries due to vaccination with the attenuated Oka strain virus. Rare cases of severe, disseminated vaccine-strain VZV infection have occurred in the immunocompromised, although rarely in HIV-infected persons. We describe a man with previously-undiagnosed human immunodeficiency virus (HIV) infection who received VZV vaccination and subsequently presented to a combat hospital in Afghanistan with disseminated varicella, respiratory failure, and sepsis. The patient recovered with ventilator and hemodynamic support, intravenous acyclovir, and empiric antibiotic therapy. DNA sequencing detected Oka strain virus from patient blood specimens. Although safe in most populations, the VZV vaccine may cause life-threatening disease in immunocompromised patients. Improved detection of HIV infection may be useful in preventing such cases.

Francisella tularensis Subtype A.II Genomic Plasticity in Comparison with Subtype A.I.

Although Francisella tularensis is considered a monomorphic intracellular pathogen, molecular genotyping and virulence studies have demonstrated important differences within the tularensis subspecies (type A). To evaluate genetic variation within type A strains, sequencing and assembly of a new subtype A.II genome was achieved for comparison to other completed F. tularensis type A genomes. In contrast with the F. tularensis A.I strains (SCHU S4, FSC198, NE061598, and TI0902), substantial genomic variation was observed between the newly sequenced F. tularensis A.II strain (WY-00W4114) and the only other publically available A.II strain (WY96-3418). Genome differences between WY-00W4114 and WY96-3418 included three major chromosomal translocations, 1580 indels, and 286 nucleotide substitutions of which 159 were observed in predicted open reading frames and 127 were located in intergenic regions. The majority of WY-00W4114 nucleotide deletions occurred in intergenic regions, whereas most of the insertions and substitutions occurred in predicted genes. Of the nucleotide substitutions, 48 (30%) were synonymous and 111 (70%) were nonsynonymous. WY-00W4114 and WY96-3418 nucleotide polymorphisms were predominantly G/C to A/T allelic mutations, with WY-00W4114 having more A+T enrichment. In addition, the A.II genomes contained a considerably higher number of intact genes and longer repetitive sequences, including transposon remnants than the A.I genomes. Together these findings support the premise that F. tularensis A.II may have a fitness advantage compared to the A.I subtype due to the higher abundance of functional genes and repeated chromosomal sequences. A better understanding of the selective forces driving F. tularensis genetic diversity and plasticity is needed.

Evolution of biomedical research during combat operations.

BACKGROUND: The implementation of a human research protection program in Afghanistan and the mobilization of the combat casualty research team have made it possible to design and efficiently conduct multifaceted, multisite, and prospective research studies in a combat environment. Still, to conduct research in such an environment, several unique challenges must be overcome. METHODS: This article describes the development and conduct of three ongoing trauma-related biomedical research studies in Afghanistan, highlighting the challenges and lessons learned within the context of these studies. RESULTS: Key challenges include the process of developing and getting approval for in-theater research protocols, the informed consent process, and logistics of conducting a biomedical research study in an austere environment. Despite these challenges, important lessons learned that can contribute to the success of a protocol include the need for clear operating procedures, judicious selection for which data points must be collected in-theater, and the importance anticipating the "fog and friction" of war. CONCLUSION: As we continue the journey toward more sophisticated research capabilities in combat, this article will help inform the design and conduct of future research performed in a theater of war. Conducting biomedical research in a combat zone is an important but difficult element of military medicine.

Francisella tularensis molecular typing using differential insertion sequence amplification.

Tularemia is a potentially fatal disease that is caused by the highly infectious and zoonotic pathogen Francisella tularensis. Despite the monomorphic nature of sequenced F. tularensis genomes, there is a significant degree of plasticity in the organization of genetic elements. The observed variability in these genomes is due primarily to the transposition of direct repeats and insertion sequence (IS) elements. Since current methods used to genotype F. tularensis are time-consuming and require extensive laboratory resources, IS elements were investigated as a means to subtype this organism. The unique spatial location of specific IS elements provided the basis for the development of a differential IS amplification (DISA) assay to detect and distinguish the more virulent F. tularensis subsp. tularensis (subtypes A.I and A.II) and subsp. holarctica (type B) strains from F. tularensis subsp. novicida and other near neighbors, including Francisella philomiragia and Francisella-like endosymbionts found in ticks. Amplicon sizes and sequences derived from DISA showed heterogeneity within members of the subtype A.I and A.II isolates but not the type B strains. These differences were due to a 312-bp fragment derived from the IS element ISFtu1. Analysis of wild-type F. tularensis isolates by DISA correlated with pulsed-field gel electrophoresis genotyping utilizing two different restriction endonucleases and provided rapid results with minimal sample processing. The applicability of this molecular typing assay for environmental studies was demonstrated by the accurate identification and differentiation of tick-borne F. tularensis. The described approach to IS targeting and amplification provides new capability for epidemiological investigations and characterizations of tularemia source outbreaks.

Large direct repeats flank genomic rearrangements between a new clinical isolate of Francisella tularensis subsp. tularensis A1 and Schu S4.

Francisella tularensis subspecies tularensis consists of two separate populations A1 and A2. This report describes the complete genome sequence of NE061598, an F. tularensis subspecies tularensis A1 isolated in 1998 from a human with clinical disease in Nebraska, United States of America. The genome sequence was compared to Schu S4, an F. tularensis subspecies tularensis A1a strain originally isolated in Ohio in 1941. It was determined that there were 25 nucleotide polymorphisms (22 SNPs and 3 indels) between Schu S4 and NE061598; two of these polymorphisms were in potential virulence loci. Pulsed-field gel electrophoresis analysis demonstrated that NE061598 was an A1a genotype. Other differences included repeat sequences (n = 11 separate loci), four of which were contained in coding sequences, and an inversion and rearrangement probably mediated by insertion sequences and the previously identified direct repeats I, II, and III. Five new variable-number tandem repeats were identified; three of these five were unique in NE061598 compared to Schu S4. Importantly, there was no gene loss or gain identified between NE061598 and Schu S4. Interpretation of these data suggests there is significant sequence conservation and chromosomal synteny within the A1 population. Further studies are needed to determine the biological properties driving the selective pressure that maintains the chromosomal structure of this monomorphic pathogen.

Complete genome sequence of Francisella tularensis subspecies holarctica FTNF002-00.

Francisella tularensis subspecies holarctica FTNF002-00 strain was originally obtained from the first known clinical case of bacteremic F. tularensis pneumonia in Southern Europe isolated from an immunocompetent individual. The FTNF002-00 complete genome contains the RD(23) deletion and represents a type strain for a clonal population from the first epidemic tularemia outbreak in Spain between 1997-1998. Here, we present the complete sequence analysis of the FTNF002-00 genome. The complete genome sequence of FTNF002-00 revealed several large as well as small genomic differences with respect to two other published complete genome sequences of F. tularensis subsp. holarctica strains, LVS and OSU18. The FTNF002-00 genome shares >99.9% sequence similarity with LVS and OSU18, and is also approximately 5 MB smaller by comparison. The overall organization of the FTNF002-00 genome is remarkably identical to those of LVS and OSU18, except for a single 3.9 kb inversion in FTNF002-00. Twelve regions of difference ranging from 0.1-1.5 kb and forty-two small insertions and deletions were identified in a comparative analysis of FTNF002-00, LVS, and OSU18 genomes. Two small deletions appear to inactivate two genes in FTNF002-00 causing them to become pseudogenes; the intact genes encode a protein of unknown function and a drug:H(+) antiporter. In addition, we identified ninety-nine proteins in FTNF002-00 containing amino acid mutations compared to LVS and OSU18. Several non-conserved amino acid replacements were identified, one of which occurs in the virulence-associated intracellular growth locus subunit D protein. Many of these changes in FTNF002-00 are likely the consequence of direct selection that increases the fitness of this subsp. holarctica clone within its endemic population. Our complete genome sequence analyses lay the foundation for experimental testing of these possibilities.

Phylogeography of Francisella tularensis: global expansion of a highly fit clone.

Francisella tularensis contains several highly pathogenic subspecies, including Francisella tularensis subsp. holarctica, whose distribution is circumpolar in the northern hemisphere. The phylogeography of these subspecies and their subclades was examined using whole-genome single nucleotide polymorphism (SNP) analysis, high-density microarray SNP genotyping, and real-time-PCR-based canonical SNP (canSNP) assays. Almost 30,000 SNPs were identified among 13 whole genomes for phylogenetic analysis. We selected 1,655 SNPs to genotype 95 isolates on a high-density microarray platform. Finally, 23 clade- and subclade-specific canSNPs were identified and used to genotype 496 isolates to establish global geographic genetic patterns. We confirm previous findings concerning the four subspecies and two Francisella tularensis subsp. tularensis subpopulations and identify additional structure within these groups. We identify 11 subclades within F. tularensis subsp. holarctica, including a new, genetically distinct subclade that appears intermediate between Japanese F. tularensis subsp. holarctica isolates and the common F. tularensis subsp. holarctica isolates associated with the radiation event (the B radiation) wherein this subspecies spread throughout the northern hemisphere. Phylogenetic analyses suggest a North American origin for this B-radiation clade and multiple dispersal events between North America and Eurasia. These findings indicate a complex transmission history for F. tularensis subsp. holarctica.

Paired-end sequence mapping detects extensive genomic rearrangement and translocation during divergence of Francisella tularensis subsp. tularensis and Francisella tularensis subsp. holarctica populations.

Comparative genome hybridization of the Francisella tularensis subsp. tularensis and F. tularensis subsp. holarctica populations have shown that genome content is highly conserved, with relatively few genes in the F. tularensis subsp. tularensis genome being absent in other F. tularensis subspecies. To determine if organization of the genome differs between global populations of F. tularensis subsp. tularensis and F. tularensis subsp. holarctica, we have used paired-end sequence mapping (PESM) to identify regions of the genome where synteny is broken. The PESM approach compares the physical distances between paired-end sequencing reads of a library of a wild-type reference F. tularensis subsp. holarctica strain to the predicted lengths between the reads based on map coordinates of two different F. tularensis genome sequences. A total of 17 different continuous regions were identified in the F. tularensis subsp. holarctica genome (CR(holar)(c)(tica)) which are noncontiguous in the F. tularensis subsp. tularensis genome. Six of the 17 different CR(holarctica) are positioned as adjacent pairs in the F. tularensis subsp. tularensis genome sequence but are translocated in F. tularensis subsp. holarctica, implying that their arrangements are ancestral in F. tularensis subsp. tularensis and derived in F. tularensis subsp. holarctica. PCR analysis of the CR(holarctica) in 88 additional F. tularensis subsp. tularensis and F. tularensis subsp. holarctica isolates showed that the arrangements of the CR(holarctica) are highly conserved, particularly in F. tularensis subsp. holarctica, consistent with the hypothesis that global populations of F. tularensis subsp. holarctica have recently experienced a periodic selection event or they have emerged from a recent clonal expansion. Two unique F. tularensis subsp. tularensis-like strains were also observed which likely are derived from evolutionary intermediates and may represent a new taxonomic unit.