Antibody evasion by SARS-CoV-2 Omicron subvariants BA.2.12.1, BA.4 and BA.5.

SARS-CoV-2 Omicron subvariants BA.2.12.1 and BA.4/5 have surged notably to become dominant in the United States and South Africa, respectively1,2. These new subvariants carrying further mutations in their spike proteins raise concerns that they may further evade neutralizing antibodies, thereby further compromising the efficacy of COVID-19 vaccines and therapeutic monoclonals. We now report findings from a systematic antigenic analysis of these surging Omicron subvariants. BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals than BA.2. However, BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections. Mutation at spike residue L452 found in both BA.2.12.1 and BA.4/5 facilitates escape from some antibodies directed to the so-called class 2 and 3 regions of the receptor-binding domain3. The F486V mutation found in BA.4/5 facilitates escape from certain class 1 and 2 antibodies but compromises the spike affinity for the viral receptor. The R493Q reversion mutation, however, restores receptor affinity and consequently the fitness of BA.4/5. Among therapeutic antibodies authorized for clinical use, only bebtelovimab retains full potency against both BA.2.12.1 and BA.4/5. The Omicron lineage of SARS-CoV-2 continues to evolve, successively yielding subvariants that are not only more transmissible but also more evasive to antibodies.

Epigenetic Aging and Musculoskeletal Outcomes in a Cohort of Women Living With HIV.

BACKGROUND: The relationship between accelerated epigenetic aging and musculoskeletal outcomes in women with HIV (WWH) has not been studied. METHODS: We measured DNA methylation age using the Infinium MethylationEPIC BeadChip in a cohort from the Women's Interagency HIV Study (n = 190) with measures of bone mineral density (BMD) and physical function. We estimated 6 biomarkers of epigenetic aging-epigenetic age acceleration (EAA), extrinsic EAA, intrinsic EAA, GrimAge, PhenoAge, and DNA methylation-estimated telomere length-and evaluated associations of epigenetic aging measures with BMD and physical function. We also performed epigenome-wide association studies to examine associations of DNA methylation signatures with BMD and physical function. RESULTS: This study included 118 WWH (mean age, 49.7 years; 69% Black) and 72 without HIV (mean age, 48.9 years; 69% Black). WWH had higher EAA (mean ± SD, 1.44 ± 5.36 vs -1.88 ± 5.07; P < .001) and lower DNA methylation-estimated telomere length (7.13 ± 0.31 vs 7.34 ± 0.23, P < .001) than women without HIV. There were no significant associations between accelerated epigenetic aging and BMD. Rather, measures of accelerated epigenetic aging were associated with lower physical function. CONCLUSIONS: Accelerated epigenetic aging was observed in WWH as compared with women without HIV and was associated with lower physical function in both groups.

Menopause-Associated Changes in Mandibular Bone Microarchitecture Are Site-Specific.

BACKGROUND: There are conflicting reports on the effects of decreased estrogen levels on mandibular bone microarchitecture. Whether these effects are consistent throughout the mandible is unclear and may have important implications for treatment planning. PURPOSE: The goal of this study was to evaluate trabecular and cortical bone microstructure in the mandibular condyle and the mandibular basal bone and compare these sites between premenopausal and postmenopausal women. STUDY DESIGN, SETTING, SAMPLE: Participants were recruited for a cross-sectional cohort study at Columbia University Irving Medical Center. Each participant had cone-beam computed tomography taken of their mandibular condyles and the basal bone. Exclusion criteria for the population included a) current chemotherapy or immunotherapy; b) history of bisphosphonate or other osteoporosis therapy; and c) currently pregnant, nursing, or on hormonal birth control. INDEPENDENT VARIABLE: The predictor variables are menopausal status (before or after menopause) and mandibular region of interest (condyle/basal bone). MAIN OUTCOME VARIABLE: Parameters of interest included the following indicators of bone quality: trabecular bone volume fraction, trabecular thickness, trabecular number, trabecular separation, cortical bone volume fraction, cortical thickness, and cortical porosity. COVARIATES: Covariates included demographic variables such as age, estrogen levels, and ethnicity. ANALYSES: Quantitative microstructure analyses were conducted on cone-beam computed tomography images, and differences between groups for continuous measures (including age) were assessed with an unpaired t-test, and demographic variables were assessed by χ2. Statistical significance was recorded at P < .05. RESULTS: The premenopausal and postmenopausal groups each had 31 participants, with the following average age: premenopausal = 43.9 ± 6.9 versus postmenopausal = 57.5 ± 7.6 years old; P < .001, and estrogen levels: premenopausal = 91.77 ± 80.13 pg/ml versus postmenopausal = 41.44 ± 61.62 pg/ml; P < .01). Postmenopausal women had significantly greater condylar trabecular separation (0.61 ± 0.18 vs 0.47 ± 0.11 mm; P < .001) and lower trabecular number (1.03 ± 0.18 vs 1.21 ± 0.19 mm-1; P < .001) compared to premenopausal women. There were no significant differences in the basal bone microarchitectural parameters between the menopausal groups. CONCLUSION AND RELEVANCE: Menopause is associated with mandibular condylar trabecular bone loss but has minimal effects on the mandibular basal bone. This may have important ramifications for treatment planning in advanced-age individuals.

Postmenopausal women with HIV have increased tooth loss.

BACKGROUND: With effective antiretroviral therapy, people with HIV (PWH) are living longer and aging; the majority of PWH in the United States are now over the age of 50 and in women have gone through the menopause transition. Menopause potentiates skeletal bone loss at the spine, hip, and radius in PWH. The alveolar bone which surronds the teeth is different than long bones because it is derived from the neural crest. However, few studies have assessed the oral health and alveolar bone in middle aged and older women with HIV. Therefore, the objective of this study was to evaluate periodontal disease and alveolar bone microarchitecture in postmenopausal women with HIV. METHODS: 135 self-reported postmenopausal women were recruited (59 HIV-, 76 HIV + on combination antiretroviral therapy with virological suppression) from a single academic center. The following parameters were measured: cytokine levels (IFN-γ, TNF-α, IL-1ß, IL-2, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17 A, OPG, and RANKL) in gingival crevicular fluid, bleeding on probing, probing depth, clinical attachment loss, number of teeth present, alveolar crestal height, and alveolar bone microarchitecture. RESULTS: The mean age of participants was 57.04+/-6.25 years and a greater proportion of women with HIV were black/African American (HIV + 68.42%, HIV- 23.73%; p < 0.001). There was no significant difference in bleeding on probing (p = 0.17) and attachment loss (p = 0.39) between women who were HIV infected vs. HIV uninfected. Women with HIV had significantly higher RANKL expression in Gingival Crevicular Fluid (HIV + 3.80+/-3.19 pg/ul, HIV- 1.29+/-2.14 pg/ul ; p < 0.001), fewer teeth present (HIV + 17.75+/-7.62, HIV- 22.79+/-5.70; p < 0.001), ), lower trabecular number (HIV + 0.08+/-0.01, HIV- 0.09+/-0.02; p = 0.004) and greater trabecular separation (HIV + 9.23+/-3.11, HIV- 7.99+/-3.23; p = 0.04) compared to women without HIV that remained significant in multivariate logistic regression analysis in a sub-cohort after adjusting for age, race/ethnicity, smoking status, and diabetes. CONCLUSION: Postmenopausal women with HIV have deterioration of the alveolar trabecular bone microarchitecture that may contribute to greater tooth loss.

Evaluation of the mandibular condylar bone microarchitecture in people living with HIV.

OBJECTIVES: People living with HIV (PLWH) have been shown to have lower bone density at the spine, hip, and radius. However, whether a similar bone phenotype is seen in craniofacial bones is not known. The goal of this study was to evaluate the bone microarchitecture of the mandibular condyle in PLWH. METHODS: We recruited 212 participants, which included 88 HIV-negative participants and 124 PLWH on combination antiretroviral therapy with virological suppression from a single academic center. Each participant filled out a validated temporomandibular disorder (TMD) pain screening questionnaire and had cone beam computed tomography (CBCT) of their mandibular condyles. Qualitative radiographic evidence of temporomandibular joint disorders-osteoarthritis (TMJD-OA) assessment and quantitative microarchitecture analysis of their mandibular condylar bones were conducted. RESULTS: There was no statistically significant difference in either self-reported TMD or in radiographic evidence of TMJD-OA in PLWH compared with HIV-negative controls. Linear regression analysis revealed that positive HIV status remained significantly associated with increased trabecular thickness, decreased cortical porosity, and increased cortical bone volume fraction after adjusting for race, diabetes, sex, and age. CONCLUSION: PLWH have increased mandibular condylar trabecular bone thickness and cortical bone volume fraction compared with HIV-negative controls.

Expert Recommendations on Optimizing the Diagnosis and Management of Gastroesophageal Reflux Disease Associated with Comorbidities in the Indian Population.

Gastroesophageal reflux disease (GERD) is among the most prevalent gastrointestinal (GI) disorders. It is known to often coexist with other chronic diseases such as asthma, chronic obstructive pulmonary disease (COPD), obesity, diabetes mellitus (DM), and hypertension. Upper endoscopy, esophageal manometry, and impedance-pH monitoring are a few invasive diagnostic options that are reserved for selected GERD patients. Symptom assessment by using questionnaires, such as the frequency scale for the symptoms of GERD (FSSG), is simple, convenient, noninvasive, and inexpensive. These questionnaires are widely used to facilitate diagnosis and appropriate treatment. Early diagnosis of GERD and timely management may improve clinical outcomes in patients. Proton pump inhibitors (PPIs) are the preferred therapy for GERD. However, evidence indicates that excessive and extended use of PPIs is linked to adverse events. An overview of the diagnosis and management of GERD, as well as an evidence-based overview of the relationship between GERD and asthma, COPD, obesity, DM, and hypertension, is presented in this review. Expert opinions and recommendations for diagnosing GERD using invasive tests and validated questionnaires have also been mentioned.

Human Immunodeficiency Virus (HIV) and Menopause Are Independently Associated With Lower Bone Mineral Density: Results From the Women's Interagency HIV Study.

BACKGROUND: We previously reported lower bone mineral density (BMD) among premenopausal women with HIV (WWH) compared to women without HIV (HIV-). Rate of bone loss may be even greater for WWH during the menopausal transition. METHODS: Pre-, peri- and postmenopausal women in the Women\'s Interagency HIV Study (WIHS) underwent whole body DXA and central quantitative computed tomography to measure areal BMD (aBMD) and volumetric BMD (vBMD), respectively. Multivariable regression models with covariates associated with low aBMD (T score < -1.0) in univariate analyses (P≤.05) and known risk factors for low BMD assessed contributions of HIV and menopausal stage to the prediction of aBMD. RESULTS: Compared to HIV- women, in unadjusted analyses, WWH had 5-9% lower aBMD at the lumbar spine (P=.001), femoral neck (P=.04), total hip (P=.003) and the ultradistal radius (P=.004), and higher osteoporosis prevalence (T score<-2.5) at the ultradistal radius only (13.5% vs 0%, P=.0003). WWH also had lower vBMD at the spine and hip. In fully adjusted models, HIV independently predicted reduced aBMD at the lumbar spine, total hip, femoral neck, and ultradistal radius; menopausal stage remained a significant predictor of lumbar spine and ultradistal radius aBMD. CONCLUSIONS: HIV infection and menopausal stage were independent predictors of lower BMD, and had an additive effect on lumbar spine and total hip BMD. Additional research is needed to better understand underlying mechanisms by which HIV impacts BMD as women age and transition through menopause, and develop strategies to mitigate osteoporosis and fracture risk in this growing population.

SARS-CoV-2 RNA Shedding in Semen and Oligozoospermia of Patient with Severe Coronavirus Disease 11 Weeks after Infection.

We report severe acute respiratory syndrome coronavirus 2 in semen by using quantitative reverse transcription PCR during the late convalescent phase. Virus was associated with adequate humoral and cell-mediated responses, suggesting possible seeding of the immune-privileged testes. We provide longitudinal semen quality data for 6 other men, including 3 who had oligozoospermia.

Prolonged severe acute respiratory syndrome coronavirus 2 persistence, attenuated immunologic response, and viral evolution in a solid organ transplant patient.

Unlike immunocompetent hosts, the duration of viral persistence after infection with severe acute respiratory syndrome coronavirus 2 can be prolonged in immunosuppressed patients. Here, we present a case of viral persistence for over 19 weeks in a patient with a history of solid organ transplant and explore the clinical, virologic, and immunologic course. Our patient still demonstrated viral persistence at 138 days with low polymerase chain reaction cycle threshold values and evidence of continuing viral sequence evolution indicative of ongoing virus replication. These findings have important implications for infection prevention and control recommendations in immunosuppressed patients. Immune response, including neutralizing antibody titers, T cell activity, and cytokine levels, peaked around days 44-72 after diagnosis. Anti-S trimer antibodies were low at all time points, and T cell response was attenuated by day 119. As immune response waned and viral load increased, increased genetic diversity emerged, suggesting a mechanism for the development of viral variants.

Epigenetic Aging Biomarkers Associated With Cognitive Impairment in Older African American Adults With Human Immunodeficiency Virus (HIV).

BACKGROUND: Accelerated epigenetic aging using DNA methylation (DNAm)-based biomarkers has been reported in people with human immunodeficiency virus (HIV, PWH), but limited data are available among African Americans (AA), women, and older PWH. METHODS: DNAm was measured using Illumina EPIC Arrays for 107 (69 PWH and 38 HIV-seronegative controls) AA adults ≥60 years in New York City. Six DNAm-based biomarkers of aging were estimated: (1) epigenetic age acceleration (EAA), (2) extrinsic epigenetic age acceleration (EEAA), (3) intrinsic epigenetic age acceleration (IEAA), (4) GrimAge, (5) PhenoAge, and (6) DNAm-estimated telomere length (DNAm-TL). The National Institutes of Health (NIH) Toolbox Cognition Battery (domains: executive function, attention, working memory, processing speed, and language) and Montreal Cognitive Assessment (MoCA) were administered. Participants were assessed for frailty by the Fried criteria. RESULTS: The PWH and control groups did not differ by sex, chronological age, or ethnicity. In total, 83% of PWH had a viral load <50 copies/mL, and 94% had a recent CD4 ≥200 cells/µL. The PWH group had a higher EAA, EEAA, GrimAge, and PhenoAge, and a lower DNAm-TL compared to the controls. IEAA was not different between groups. For PWH, there were significant negative correlations between IEAA and executive function, attention, and working memory and PhenoAge and attention. No associations between biomarkers and frailty were detected. CONCLUSIONS: Evidence of epigenetic age acceleration was observed in AA older PWH using DNAm-based biomarkers of aging. There was no evidence of age acceleration independent of cell type National Institutes of Health composition (IEAA) associated with HIV, but this measure was associated with decreased cognitive function among PWH.

Longitudinal Viral Load Monitoring Using Home-Collected Dried Blood Spot Specimens of MSM Living with HIV: Results from a Feasibility Pilot Study.

Novel viral load monitoring strategies are needed to help individuals maintain an undetectable viral load (UVL). In 2018, U.S. MSM living with HIV with a past detectable VL received a dried blood spot (DBS) kit at baseline and 3-month follow-up and returned specimens to a research laboratory. Of 56 consenting participants, 91% returned specimens at baseline and 77% at 3-month follow-up; 74% who returned two specimens had UVL at both time points. At-home DBS collection and longitudinal VL monitoring is feasible among U.S. MSM with fluctuating viral load. This complementary approach to clinical care could improve viral suppression maintenance.

RESUMEN: Se necesitan nuevas estrategias para evaluar los niveles de la carga viral para ayudar a las personas viviendo con VIH a mantener una carga viral indetectable (CVI). En 2018, hombres viviendo con VIH, que reportaron sexo con hombres y una carga viral detectable, recibieron dos paquetes de materiales para colectar muestras de sangre seca después de completar una evaluación basal y después de tres meses de seguimiento. Participantes devolvieron las muestras de sangre seca a un laboratorio. De 56 participantes que dieron su consentimiento a participar en el estudio, el 91% devolvió una muestra de sangre seca al inicio del estudio y el 77% a los 3 meses de seguimiento. Además, el 74% que devolvió dos muestras de sangre seca tenían CVI en ambos puntos de tiempo. La colección de sangre seca en el hogar y el monitoreo longitudinal de la carga viral de VIH es factible entre los hombres viviendo con el VIH y que tienen sexo con hombres. Los resultados de este estudio pueden proporcionar un enfoque complementario a la atención clínica para mejorar la supresión viral del VIH.

Oxidized Regenerated Cellulose/Collagen Dressings: Review of Evidence and Recommendations.

OBJECTIVE: Healthcare systems are being challenged to manage increasing numbers of nonhealing wounds. Wound dressings are one of the first lines of defense in wound management, and numerous options exist. The oxidized regenerated cellulose (ORC)/collagen dressing may offer healthcare providers a robust and cost-effective tool for use in a variety of wounds. DESIGN: A multidisciplinary panel meeting was convened to discuss the use of ORC/collagen dressings in wound care and provide practice recommendations. A literature search was conducted to provide a brief review of the peer-reviewed studies published between January 2000 and March 2016 to inform the meeting. SETTING: A 2-day panel meeting convened in February 2017. PARTICIPANTS: Healthcare providers with experience using ORC/collagen dressings. This multidisciplinary panel of 15 experts in wound healing included podiatrists, wound care specialists (doctors, certified wound care nurses, and research scientists), and an orthopedist. RESULTS: The literature search identified 58 articles, a majority of which were low levels of evidence (69.3% were level 3 or lower). Panel members identified wound types, such as abrasions, burns, stalled wounds, diabetic foot ulcers, and pressure injuries, where ORC/collagen dressing use could be beneficial. Panel members then provided recommendations and technical pearls for the use of ORC/collagen dressings in practice. Barriers to ORC/collagen dressing use were discussed, and potential resolutions were offered. CONCLUSIONS: An ORC/collagen dressing can be a critical tool for clinicians to help manage a variety of wounds. Clinical and economic studies comparing standard-of-care dressings and plain collagen dressings to ORC/collagen dressings are needed.

Extracorporeal shockwave therapy (ESWT) in an outpatient wound care clinic: case series analysis of a non-invasive technology in the management of chronic wounds for wound bed preparation.

BACKGROUND: Extracorporeal shockwave therapy (ESWT) has been shown to reduce wound dimensions and healing time in chronic wounds and should be considered a valuable tool in the healing of chronic complex lower extremity wounds. PURPOSE: The aim of this small case series was to evaluate the effect of ESWT on complex chronic wounds in patients with multiple comorbidities in a medically underserved outpatient wound care clinic setting. METHODS: All patients had baseline wound measurements taken. Pictures of the wounds were also taken at the time of the initial visit. Patients selected for ESWT received weekly treatments for a maximum recorded duration of 12 weeks in the form of focused electro-hydraulic acoustic pulses. Wound beds were cleansed according to standard of care. RESULTS: Thirteen patients were followed with a total of 18 wounds treated. After retrospectively analyzing the data, 3 subjects and a total of 5 wounds were excluded, leaving 10 total subjects and 13 wounds. Out of these wounds, 12 healed completely by or before week 12 of ESWT. All wounds demonstrated significant wound dimension reduction during the first 12 weeks of treatment. CONCLUSION: ESWT could offer accessible, fast, safe, and cost-effective management of some complex chronic wounds. Further research is needed to validate these findings.

A rare case report of bilateral Purtscher-like retinopathy in juvenile dermatomyositis.

Purpose: To report a rare case of bilateral Purtscher-like retinopathy (PLR) in a young adult diagnosed with dermatomyositis. Method: A case report with multi-modal imaging. Result: A 17-year-old male presented with subacute marked diminution of vision along with arthralgia, weakness of all four limbs and development of multiple rashes around body. Fundus examination revealed bilateral multiple Purtscher flecken, pseudo-cherry red spot, and intra-retinal haemorrhages with cotton wool spots. Systemic and laboratory examinations, magnetic resonance imaging (MRI) and biopsy of tissue confirmed the diagnosis of juvenile dermatomyositis with PLR. Conclusion: Dermatomyositis, being a rare cause of PLR, should essentially be considered as one of the differentials as timely intervention can alter the course of disease and prove life-saving for the patient.

Men with HIV Have Increased Alveolar Bone Loss.

Background: Periodontal health in men with HIV remains understudied, despite suggestions of associations between HIV infection and gingival pocketing, periodontal attachment loss, and gingival inflammation. As antiretroviral therapy (ART) has improved the quality of life for people living with HIV (PLWH), aging-related risk factors and comorbidities, including periodontitis, have emerged. This study aims to assess alveolar bone height, gingival crevicular fluid (GCF) cytokines, and periodontal disease activity in men with and without HIV. Methods: Ninety-three men (50 HIV+, 43 HIV‒) aged 35-70 years were recruited from Columbia University Irving Medical Center clinics. Periodontal examination, GCF collection, and intraoral radiographs were conducted. Results: While no significant differences were observed in bleeding on probing, clinical attachment loss and pocket depths, men with HIV exhibited significantly greater alveolar crestal height on radiographs compared to men without HIV (HIV + 3.41+/-1.35 mm, HIV- 2.64+/-1.01 mm; p = 0.004), reflecting greater alveolar bone loss. GCF IL6 levels showed a trend towards elevation in men with HIV (HIV + 0.349+/-0.407 pg/ml, HIV- 0.220+/-0.228 pg/ml; p = 0.059). Conclusions: Men with HIV demonstrate increased alveolar bone loss compared to those without HIV, possibly mediated by elevated IL6 levels. These results underscore the importance of comprehensive oral health management in PLWH and highlight the need for further research understanding the mechanisms linking HIV infection, cytokine dysregulation, and periodontal health.

Carbon footprint of industry-sponsored late-stage clinical trials.

OBJECTIVES: To quantify the carbon footprint from a sample of pharma industry sponsored phase III trials. To develop an approach that can readily be applied to future trials by AstraZeneca and other trial sponsors. DESIGN: Life cycle assessment including all the sources of carbon emissions associated with a completed, an ongoing and a planned clinical trial. The methodology followed the guidance on appraising the sustainability of Care Pathways, developed by the UK National Health Service in collaboration with parties across the healthcare system. SETTING: Three multicentre late phase trials. One completed heart failure trial, one ongoing oncology trial and one asthma trial with the addition of devices to be representative of current practice. PARTICIPANTS: The three trials had a total number of 7412 participants. MAIN OUTCOME MEASURES: Total carbon emissions from each trial, the drivers of those emissions and the emissions per patient. RESULTS: The total carbon footprint for the cardiovascular trial was calculated as 2498 tonnes carbon dioxide equivalents (CO2e), the first 3 years of the oncology trial resulted in 1632 tonnes CO2e and the respiratory trial 1437 tonnes CO2e. CONCLUSIONS: We have shown that it is feasible to perform a retrospective life cycle assessment to appraise the carbon footprint of large clinical trials and confirmed that phase III trials result in significant emissions. Having identified all the drivers of emissions and their magnitude, we are well placed to develop a plan for achieving net-zero carbon clinical trials. Now it is possible to expand the use of life cycle assessment to planned studies so that scientific aims can be achieved with a minimum of carbon emissions. We encourage other trialists to apply the same methodology as a necessary first step in reducing the carbon footprint of clinical trials.

A population pharmacokinetic model of polymyxin B based on prospective clinical data to inform dosing in hospitalized patients.

OBJECTIVES: To develop a population pharmacokinetic (PK) model with data from the largest polymyxin B-treated patient population studied to date to optimize its dosing in hospitalized patients. METHODS: Hospitalized patients receiving intravenous polymyxin B for ≥48 hours were enrolled. Blood samples were collected at steady state and drug concentrations were analysed by liquid chromotography tandem mass spectrometry (LC-MS/MS). Population PK analysis and Monte Carlo simulations were performed to determine the probability of target attainment (PTA). RESULTS: One hundred and forty-two patients received intravenous polymyxin B (1.33-6 mg/kg/day), providing 681 plasma samples. Twenty-four patients were on renal replacement therapy, including 13 on continuous veno-venous hemodiafiltration (CVVHDF). A 2-compartment model adequately described the PK with body weight as a covariate on the volume of distribution that affected Cmax, but it did not impact clearance or exposure. Creatinine clearance was a statistically significant covariate on clearance, although clinically relevant variations of dose-normalized drug exposure were not observed across a wide creatinine clearance range. The model described higher clearance in CVVHDF patients than in non-CVVHDF patients. Maintenance doses of ≥2.5 mg/kg/day or ≥150 mg/day had a PTA ≥90% (for non-pulmonary infections target) at a steady state for minimum inhibitory concentrations ≤2 mg/L. The PTA at a steady state for CVVHDF patients was lower. DISCUSSION: Fixed loading and maintenance doses of polymyxin B seemed to be more appropriate than weight-based dosing regimens in patients weighing 45-90 kg. Higher doses may be needed in patients on CVVHDF. Substantial variability in polymyxin B clearance and volume of distribution was found, suggesting that therapeutic drug monitoring may be indicated.

Genes encoding OXA-134-like enzymes are found in Acinetobacter lwoffii and A. schindleri and can be used for identification.

bla(OXA-134) genes and variants were sought in 21 species of Acinetobacter and found in A. lwoffii, genomic species 9 (regarded as synonyms), and A. schindleri. Sequencing revealed a 9-bp deletion in the gene in the type strain of genomic species 9 (ATCC 9957) relative to the gene in the type strain of A. lwoffii (ATCC 15309). Primers based on the gene without the deletion gave specific amplification of 29 of 30 clinical isolates of A. lwoffii/genomic species 9.

Recurrent Microvirgula aerodenitrificans bacteremia.

Microvirgula aerodenitrificans is a denitrifying Gram-negative organism first described by Patureau et al. in 1998 (D. Patureau et al., Int. J. Syst. Bacteriol. 48:775-782, 1998). The organism has been isolated globally but has never been described as causative of clinical infection. We describe the first human case of bacteremia attributed to M. aerodenitrificans in an infant with Pompe's disease.