Identifying Implementation Determinants and Strategies for Long-Acting Injectable Cabotegravir-Rilpivirine in People with HIV Who Are Virally Unsuppressed

BACKGROUND

Early evidence suggests long-acting injectable cabotegravir and rilpivirine (LA-CAB/RPV) may be beneficial for people with HIV (PWH) who are unable to attain viral suppression (VS) on oral therapy. Limited guidance exists on implementation strategies for this population.

SETTING

Ward 86, a clinic serving publicly insured PWH in San Francisco.

METHODS

We describe multi-level determinants of and strategies for LA-CAB/RPV implementation for PWH without VS, using the Consolidated Framework for Implementation Research. To assess patient and provider-level determinants, we drew on pre-implementation qualitative data. To assess inner and outer context determinants, we undertook a structured mapping process.

RESULTS

Key patient-level determinants included perceived ability to adhere to injections despite oral adherence difficulties and care engagement challenges posed by unmet subsistence needs; strategies to address these determinants included a direct-to-inject approach, small financial incentives, and designated drop-in days. Provider-level determinants included lack of time to obtain LA-CAB/RPV, assess injection response, and follow-up late injections; strategies included centralizing eligibility review with the clinic pharmacist, a pharmacy technician to handle procurement and monitoring, regular multidisciplinary review of patients, and development of a clinic protocol. Ward 86 did not experience many outer context barriers due to rapid and unconstrained inclusion of LA-CAB/RPV on local formularies and ability of its affiliated hospital pharmacy to stock the medication.

CONCLUSION

Multi-level strategies to support LA-CAB/RPV implementation for PWH without VS are required, which may necessitate additional resources in some settings to implement safely and effectively. Advocacy to eliminate outer-context barriers, including prior authorizations and specialty pharmacy restrictions, is needed.

Lessons learned from U.S. rapid antiretroviral therapy initiation programs

BACKGROUND

Rapid antiretroviral therapy initiation (R-ART) for treatment of HIV has been recommended since 2017, however it has not been adopted widely across the US.

PURPOSE

The study purpose was to understand facilitators and barriers to R-ART implementation in the U.S.

RESEARCH DESIGN

This was a qualitative design involving semi-structured interviews.

STUDY SAMPLE

The study sample was comprised of the medical leadership of nine US HIV clinics that were early implementers of R-ART.

DATA COLLECTION AND ANALYSIS

In-depth, semi-structured interviews were performed. The Consolidated Framework for Implementation Research (CFIR) was used to guide thematic analysis.

RESULTS

We identified three main content areas: strong scientific rationale for R-ART, buy-in from multiple key stakeholders, and the condensed timeline of R-ART. The CFIR construct of Evidence Strength and Quality was cited as an important factor in R-ART implementation. Buy-in from key stakeholders and immediate access to medications ensured the success of R-ART implementation. Patient acceptance of the condensed timeline for ART initiation was facilitated when presented in a patient-centered manner, including empathetic communication and addressing other patient needs concurrently. The condensed timeline of R-ART presented logistical challenges and opportunities for the development of intense patient-provider relationships.

CONCLUSIONS

Results from the analysis showed that R-ART implementation should address the following: 1) logistical planning to implement HIV treatment with a condensed timeline 2) patients' mixed reactions to a new HIV diagnosis and 3) the high cost of HIV medications.

Differences in trauma-informed care implementation by clinic-level factors across Ryan White HIV clinics in the Southeastern United States

Trauma is common among people with HIV (PWH) and associated with low HIV care engagement, thus trauma-informed care (TIC) integration within HIV services is critical. From December 2019 to April 2020, we conducted surveys with 321 administrators, providers, and staff of 46 Ryan White HIV clinics (RWCs) in 8 Southeastern U.S. states to assess level of TIC implementation and clinic-level factors associated with TIC adoption. The mean score for TIC implementation was highest for the Physical Environment domain (μ = 4.08, SE = 0.07), followed by Screening, Assessment, and Treatment Services (μ = 3.96, SE = 0.07), Cross-sector Collaboration (μ = 3.75, SE = 0.08), Engagement and Involvement (μ = 3.92, SE = 0.09); and Training and Workforce Development (μ = 3.54, SE = 0.12). Greatest gaps were in staff TIC training, staff support, presence of onsite legal, spiritual, and housing services, and seeking patients' definitions of safety and developing their individualized crisis/safety plans. Across most TIC implementation domains, clinic type, urbanicity, academic affiliation, and presence of onsite psychosocial support services were associated with level of TIC adoption. Thus, RWCs have the necessary foundation to integrate TIC practices, but further progress will require addressing identified gaps. The overall lack of significant difference in TIC implementation across domains by clinic-level factors suggests that a RW network-wide approach to enhancing TIC integration is feasible.

1026. What Proportion of Infectious Diseases Physicians Have Buprenorphine Waivers to Treat Opioid Use Disorder in the United States?

Background

Since the onset of the COVID-19 pandemic, opioid-related overdose deaths have increased. Buprenorphine, a medication for opioid use disorder (OUD), is safe and effective but is underutilized and requires qualifying physicians to obtain a waiver. Infectious diseases (ID) physicians are uniquely positioned to treat OUD, as persons with OUD may present with infectious complications from injection drug use. We sought to understand the proportion and distribution of ID physicians with waivers in the United States (US).

Methods

This was a cross-sectional study merging data from the Centers for Medicare & Medicaid Services and the Drug Enforcement Agency Substance Abuse and Mental Health Services Agency. Our primary outcome was proportion of ID physicians who possess buprenorphine waivers. We used multivariable regression models to identify individual and county-level characteristics associated with buprenorphine waiver possession. We used geospatial analysis to describe county-level distribution of buprenorphine-waivered ID physicians.

Results

Among 6439 ID physicians in the US, 170 (2.6%) possessed buprenorphine waivers. Overall, 57.2% of ID physicians were male with a median 23 (IQR 15-33) years since medical school. Most (97.3%) practiced in metropolitan counties. In multivariable analysis, medical school graduation beyond 20 years was associated with lower odds of waiver possession compared to those graduating within 20 years (OR 0.59, 95% CI 0.43-0.80). ID physicians practicing in counties with median income > 50,000/year and in counties with higher proportion of uninsured residents also had lower odds of having a waiver (OR 0.58, 95% CI 0.35-0.97; OR 0.93, 95% CI 0.90-0.97). Among counties with at least one ID physician (n=519), 86.6% had no buprenorphine-waivered ID physicians (Figure 1). Figure 1County-Level Distribution of Infectious Diseases Physicians with Buprenorphine Waivers

Conclusion

Fewer than 3% of ID physicians in the US have obtained waivers to prescribe buprenorphine, highlighting missed opportunities to treat individuals with OUD, especially in rural America. Education on OUD management should be integrated into ID continuing medical education, and policies are urgently needed to expand buprenorphine access to persons without insurance.

Disclosures

All Authors: No reported disclosures.

Are Patients and Their Providers Talking About Long-Acting Injectable Antiretroviral Therapy? Penetration into Clinical Encounters at Three U.S. Care Sites

Use of long-acting injectable antiretroviral therapy depends on patient awareness, provider discussion, and patient willingness to use. We conducted a postvisit survey with patients at 3 HIV clinics in San Francisco, Chicago, and Atlanta in May 2021 to assess for inequities in these early implementation phases.

Weight gain post-ART in HIV+ Latinos/as differs in the USA, Haiti, and Latin America

Background

An obesity epidemic has been documented among adult Latinos/as in Latin America and the United States (US); however, little is known about obesity among Latinos/as with HIV (PWH). Moreover, Latinos/as PWH in the US may have different weight trajectories than those in Latin America due to the cultural and environmental contexts. We assessed weight and body mass index (BMI) trajectories among PWH initiating antiretroviral therapy (ART) across 5 countries in Latin America and the Caribbean and the US.

Methods

ART-naÿve PWH ≥18 years old, enrolled in Brazil, Honduras, Mexico, Peru, and Haiti (sites within CCA-SAnet) and the US (NA-ACCORD) starting ART between 2000 and 2017, with at least one weight measured after ART initiation were included. Participants were classified according to site/ethnicity as: Latinos/as in US, non-Latinos/as in US, Haitians, and Latinos/as in Latin America. Generalized least squares models were used to assess trends in weight and BMI. Models estimating probabilities of becoming overweight/obese (BMI ≥25 kg/m2) and of becoming obese (BMI ≥30 kg/m2) post ART initiation for males and females were fit using generalized estimating equations with a logit link and an independence working correlation structure.

Findings

Among 59,207 PWH, 9% were Latinos/as from Latin America, 9% Latinos/as from the US, 68% non-Latinos/as from the US and 14% were Haitian. At ART initiation, 29% were overweight and 14% were obese. Post-ART weight and BMI increases were steeper for Latinos/as in Latin America compared with other sites/ethnicities; however, BMI at 3-years post ART remained lower compared to Latinos/as and non-Latinos/as in the US. Among females, at 3-years post ART initiation the greatest adjusted probability of obesity was found among non-Latinas in the US (15·2%) and lowest among Latinas in Latin America (8.6%). Among males, while starting with a lower BMI, Latinos in Latin America had the greatest adjusted probability of becoming overweight or obese 3-years post-ART initiation.

Interpretation

In the Americas, PWH gain substantial weight after ART initiation. Despite environmental and cultural differences, PWH in Latin America, Haiti and Latinos and non-Latinos in the US share similar BMI trajectories on ART and high probabilities of becoming overweight and obese over time. Multicohort studies are needed to better understand the burden of other metabolic syndrome components in PWH across different countries.

887. Implementation of Long-acting Injectable Cabotegravir/Rilpivirine for HIV-1 Treatment at a Ryan White-funded Clinic in the U.S. South

Background

In January 2021, the first ever long-acting injectable (LAI) antiretroviral therapy (ART), cabotegravir/rilpivirine (CAB/RPV), was approved for maintenance HIV-1 treatment in select patients with virologic suppression. LAI-ART has the potential to improve ART adherence, reduce HIV stigma, and promote equity in care outcomes, however, implementation in real-world settings has yet to be evaluated.

Methods

We launched a pilot LAI-ART program at the largest Ryan White-funded HIV clinic in the Southeast. From 4/14/21 to 5/14/21, providers referred patients interested and willing to switch to LAI-CAB/RPV who met screening criteria. Our interdisciplinary LAI team (Clinician-Pharmacy-Nursing) verified clinical eligibility (HIV-1 < 200 c/ml ≥6 months and no history of virologic failure, resistance to either drug, or chronic HBV infection) and pursued medication access for 28-day oral lead-in and monthly injectable CAB/RPV. We describe demographic and clinical variables of referred PWH and early outcomes in accessing LAI-ART.

Results

Among 42 referrals, median age was 40.5 (Q1-Q3, 32-52) years, 83% were men, and 76% Black. Payor source distribution was 26% Private, 19% Medicare, 10% Medicaid, and 45% ADAP. At the time of referral, median CD4 count was 583 (Q1-Q3, 422-742) cells/mm³ and median sustained HIV-1 RNA < 200 c/ml was 1427 (Q1-Q3, 961-2534) days. A total of 35 patients (74%) met clinical eligibility for LAI-CAB/RPV, including 4 patients who required a transition off proton pump inhibitor therapy to accommodate oral RPV. Ineligible PWH were excluded due to evidence of RPV resistance (n=5), possible RPV hypersensitivity (n=1), and HIV non-suppression (n=1). The table summarizes the process of pursuing LAI-ART access for the initial 10 enrollees by insurance status.

Conclusion

Our experience implementing LAI-ART at a Ryan White-funded HIV clinic in the Southern U.S. has been challenged by substantial human resource capital to attain drug, delayed therapy initiation due to insurance denials, and patient ineligibility primarily due to concern for potential RPV resistance. These barriers may perpetuate disparities in ART access and virologic suppression among PWH and need to be urgently addressed so that LAI-ART can be offered equitably.

Disclosures

Lauren F. Collins, MD, MSc, Nothing to disclose Bradley L. Smith, Pharm.D., AAHIVP, Gilead Sciences, Inc (Advisor or Review Panel member) Wendy Armstrong, MD, Nothing to disclose Jonathan Colasanti, MD, Integritas CME (Consultant, develop and deliver CME content around Rapid Entry/Rapid ART)

The Intersection of HIV, Diabetes, and Race: Exploring Disparities in Diabetes Care among People Living with HIV

In a setting of universal health care access, we compared diabetes control between Caucasians and African Americans (AA) living with HIV. This was a cross-sectional analysis of data from a cohort study among military members living with HIV and diabetes. Using adjusted logistic regression models, we compared proportions of Caucasians and AA meeting the following diabetes treatment goals: hemoglobin A_1c <7.0%, blood pressure (BP) <140/90 mm Hg, low density lipoprotein cholesterol <100 mg/dL, and not smoking. We included 107 Caucasian (mean age 37 years) and 126 AA (mean age 33 years) participants. A similar proportion of Caucasians and AA were prescribed diabetes (∼60%) and BP (∼80%) medications. Yet, more Caucasians met the BP treatment goal (77% [54%, 90%]) than AA (61% [36%, 82%]). Thus, more Caucasians met the combined A_1c, BP, and cholesterol goals for diabetes control (25% [10%, 49%]) than AA (13% [5%, 31%]). Despite having equal access to health care, AA in this study have poorer diabetes control than Caucasians.

Understanding and addressing privacy and confidentiality concerns associated with the provision of mobile HIV care: a qualitative study

Less than half the people with HIV (PLWH) in the United States (US) are retained in HIV care, underscoring the importance of novel reengagement and retention strategies. Mobile HIV clinics (MHCs) are one such strategy, but privacy and confidentiality concerns have limited their use. As part of a larger mixed-methods study in Atlanta, Georgia, from June 2019- July 2020, we conducted 41 qualitative interviews with key stakeholders to explore confidentiality, privacy and stigma concerns and strategies to address them. Interviews were recorded, transcribed and coded thematically. Four key themes emerged: 1) the need to understand MHC acceptance in the context of high HIV stigma in the South, 2) the multidimensionality of confidentiality and stigma concerns (e.g., related to exterior labeling, layout, location attracting unwanted attention), 3) the counter perspective: potential for MHCs to positively reframe HIV and reduce stigma, and 4) strategies to overcome stigma and confidentiality concerns, including co-delivery of non-HIV services, unidirectional flow, and non-HIV exterior labeling. In furthering understanding of the breadth of privacy and confidentiality concerns associated with an MHC and strategies for addressing them, this exploratory study lays a critical foundation for the development of an MHC to reengage and retain PLWH in the US.

Post-traumatic stress disorder and risky opioid use among persons living with HIV and chronic pain

Persons with HIV (PWH) experience chronic pain and Post-Traumatic Stress Disorder (PTSD) at higher rates than the general population, and more often receive opioid medications to treat chronic pain. A known association exists between PTSD and substance use disorders, but less is known about the relationship between PTSD and risky opioid use among PWH taking prescribed opioid medications. In this observational study of PWH on long-term opioid medications for pain we examined associations between PTSD symptom severity based on the Post Traumatic Stress Disorder Checklist for DSM-5 (PCL-5, response range 0-80) and the following outcomes: 1) risk for opioid misuse (COMM score ≥13); 2) risky alcohol use (AUDIT score ≥8); 3) concurrent benzodiazepine prescription; and 4) morphine equivalent dose. Among 166 patients, 38 (23%) had a PCL-5 score over 38, indicating high PTSD symptom burden. Higher PCL-5 score (per 10 point difference) was associated with increased odds of opioid misuse (aOR 1.55; 95%CI: 1.31-1.83) and risky drinking (aOR: 1.28;1.07-1.52). No significant association was observed between PCL-5 score and benzodiazepine prescriptions or morphine equivalent dose. These findings suggest that when addressing alcohol and opioid use in PWH on long term opioid therapy, attention to PTSD symptoms is especially important given the higher risk for risky alcohol and opioid use among patients with this common comorbid condition.

Chronic Opioid Therapy in People Living With Human Immunodeficiency Virus: Patients' Perspectives on Risks, Monitoring, and Guidelines

Background

Chronic opioid therapy (COT) is common in people living with human immunodeficiency virus (PLHIV), but is not well studied. We assessed opioid risk behaviors, perceptions of risk, opioid monitoring, and associated Current Opioid Misuse Measure (COMM) scores of PLHIV on COT.

Methods

COT was defined as ≥3 opioid prescriptions ≥21 days apart in the past 6 months. Demographics, substance use, COMM score, and perceptions of and satisfaction with COT monitoring were assessed among PLHIV on COT from 2 HIV clinics.

Results

Among participants (N = 165) on COT, 66% were male and 72% were black, with a median age of 55 (standard deviation, 8) years. Alcohol and drug use disorders were present in 17% and 19%, respectively. In 43%, the COMM score, a measure of potential opioid misuse, was high. Thirty percent had an opioid treatment agreement, 66% a urine drug test (UDT), and 12% a pill count. Ninety percent acknowledged opioids' addictive potential. Median (interquartile range) satisfaction levels (1-10 [10 = highest]) were 10 (7-10) for opioid treatment agreements, 9.5 (6-10) for pill counts, and 10 (8-10) for UDT. No association was found between higher COMM score and receipt of or satisfaction with COT monitoring.

Conclusions

Among PLHIV on COT, opioid misuse and awareness of the addictive potential of COT are common, yet COT monitoring practices were not guideline concordant. Patients who received monitoring practices reported high satisfaction. Patient attitudes suggest high acceptance of guideline concordant care for PLHIV on COT when it occurs.

Dolutegravir Plus Lamivudine Maintains Human Immunodeficiency Virus-1 Suppression Through Week 48 in a Pilot Randomized Trial

Clinical Trials Registration

NCT02263326.

Marijuana Use and Its Associations With Pain, Opioid Dose, and HIV Viral Suppression Among Persons Living With HIV on Chronic Opioid Therapy

BACKGROUND

Medical marijuana is legal in 29 US states and the District of Columbia: both HIV and chronic pain are "approved conditions" for receipt. Chronic pain is common among people living with HIV (PLWH). We anticipate PLWH will question their providers about medical marijuana for chronic pain. We examined marijuana use and its associations with pain, opioid dose, and HIV viral suppression among PLWH receiving chronic opioid therapy.

METHODS

PLWH prescribed chronic opioid therapy were recruited into the Targeting Effective Analgesia in Clinics for HIV cohort. The main exposure variable was any past 12-month marijuana use. The primary outcomes were (1) opioid misuse (≥9 on the Current Opioid Misuse Measure) and (2) opioid dose (morphine equivalent daily dose). HIV viral load (VL) suppression (<200 copies/μL) and pain severity and interference using the Brief Pain Inventory were exploratory outcomes.

RESULTS

Participants (n = 166) were men (65%), Black (72%), and had an undetectable VL (89%). We found no significant association between current marijuana use and opioid misuse, opioid dose, or pain. Current marijuana use was associated with 3.03 times the odds of having a detectable VL (95% odds ratio: 1.11-8.31, P = 0.03) while controlling for depressive symptoms and other substance use.

DISCUSSION

We did not detect an association between marijuana use and opioid misuse behaviors, opioid dose, or pain. In an exploratory analysis, current marijuana use was associated with 3× greater odds of having a detectable VL. This study provides insights into potential consequences of marijuana use among PLWH with chronic pain.

Low provider and staff self-care in a large safety-net HIV clinic in the Southern United States: Implications for the adoption of trauma-informed care

Objective:

This mixed-methods needs assessment study examined self-care practices among providers, staff, and administrators at an HIV clinic and identified barriers and facilitators to strengthening self-care services in this setting.

Methods:

Surveys (n = 31) and qualitative interviews (n = 23) were conducted with staff, providers, and administrators at a large, safety-net HIV clinic.

Results:

Surveys indicated an overall absence of formal self-care services including resources to manage stress, opportunities to debrief, and formal mechanisms to voice concerns. Based on interviews with staff and providers, deficiencies in self-care services included support for dealing with complex patients, formal mechanisms for feedback, and time for self-care. Administrators recognized the need for more support, acknowledged that opportunities for employees to voice concerns were lacking, and felt that implementing multi-disciplinary team meetings could improve morale and reduce stress and burnout.

Conclusion:

This assessment revealed a need to enhance self-care in safety-net HIV services. Adoption of trauma-informed care, which includes activities to strengthen self-care, could reduce workplace burnout.

HIV Physicians and Chronic Opioid Therapy: It's Time to Raise the Bar

Clinical practice that utilizes chronic opioid therapy has been recognized as one major cause of the opioid crisis. Among patients living with HIV, the risks associated with chronic opioid therapy may be complicated by factors such as co-occurring mental health diagnoses, substance use, and economic marginalization. Improving opioid prescribing practices in HIV clinics requires attention to these and other characteristics common to HIV care. In the context of a randomized controlled trial testing an intervention to improve opioid prescribing practices in HIV outpatient clinics, we interviewed physicians about their perspectives on chronic opioid therapy. Overwhelmingly, physicians voiced ambivalence about their own knowledge and comfort with prescription opioids. They raised concerns about the impact of opioid prescribing on patient-provider relationships and the increasing workload associated with prescribing and monitoring patients. In this report, we explore these concerns and propose several strategies for improving clinical care in which chronic opioid therapy is addressed.

Study protocol for the targeting effective analgesia in clinics for HIV (TEACH) study - a cluster randomized controlled trial and parallel cohort to increase guideline concordant care for long-term opioid therapy among people living with HIV

Background: People living with HIV (PLWH) frequently experience chronic pain and receive long-term opioid therapy (LTOT). Adherence to opioid prescribing guidelines among their providers is suboptimal. Objective: This paper describes the protocol of a cluster randomized trial, targeting effective analgesia in clinics for HIV (TEACH), which tested a collaborative care intervention to increase guideline-concordant care for LTOT among PLWH. Methods: HIV physicians and advanced practice providers (n = 41) were recruited from September 2015 to December 2016 from two HIV clinics in Boston and Atlanta. Patients receiving LTOT from participating providers were enrolled through a waiver of informed consent (n = 187). After baseline assessment, providers were randomized to the control group or the year-long TEACH intervention involving: (1) a nurse care manager and electronic registry to assist with patient management; (2) opioid education and academic detailing; and (3) facilitated access to addiction specialists. Randomization was stratified by site and LTOT patient volume. Primary outcomes (≥2 urine drug tests, early refills, provider satisfaction) were collected at 12 months. In parallel, PLWH receiving LTOT (n = 170) were recruited into a longitudinal cohort at both clinics and underwent baseline and 12-month assessments. Secondary outcomes were obtained through patient self-report among participants enrolled in both the cohort and the RCT (n = 117). Conclusions: TEACH will report the effects of an intervention on opioid prescribing for chronic pain on both provider and patient-level outcomes. The results may inform delivery of care for PLWH on LTOT for chronic pain at a time when opioid practices are being questioned in the US.

Provider opioid prescribing practices and the belief that opioids keep people living with HIV engaged in care: a cross-sectional study

We describe HIV providers' opioid prescribing practices and assess whether belief that chronic opioid therapy (COT) keeps people living with HIV (PLWH) engaged in care is associated with differences in these practices among providers from two HIV clinics. We conducted logistic regression to evaluate the association between the belief that COT keeps PLWH engaged in care and at least one component of guideline-recommended care (i.e., urine drug tests, treatment agreements, and/or prescription monitoring program use). The sample included 41 providers with a median age of 42 years, 63% female, 37% non-white. Routine adherence to guideline-recommended practices was: 34% urine drug tests, 27% treatment agreements, and 17% prescription monitoring program. Over half [54%] agreed that COT keeps PLWH engaged in care. There was no significant association between belief that COT keeps PLWH engaged in care and routinely providing any recommended COT care component (aOR 2.38; 95% CI 0.65-8.73). Most HIV providers do not routinely follow guidelines for opioid prescribing. We observed a positive association between belief that COT keeps PLWH engaged in care and following any guideline-recommended prescribing practices, although the result was not statistically significant. Interventions are needed to improve guideline-concordant care for COT by HIV providers.

Implementation of a Rapid Entry Program Decreases Time to Viral Suppression Among Vulnerable Persons Living With HIV in the Southern United States

Background

Rapid entry programs (REPs) improve time to antiretroviral therapy (ART) initiation (TAI) and time to viral suppression (TVS). We assessed the feasibility and effectiveness of a REP in a large HIV clinic in Atlanta, Georgia, serving a predominately un- or underinsured population.

Methods

The Rapid Entry and ART in Clinic for HIV (REACH) program was implemented on May 16, 2016. We performed a retrospective cohort study with the main independent variable being period of enrollment: January 1, 2016, through May 15, 2016 (pre-REACH); May 16, 2016, through July 31, 2016 (post-REACH). Included individuals were HIV-infected and new to the clinic with detectable HIV-1 RNA. Six-month follow-up data were collected for each participant. Survival analyses were conducted for TVS. Logistic and linear regression analyses were used to evaluate secondary outcomes: attendance at first clinic visit, viral suppression, TAI, and time to first attended provider visit.

Results

There were 117 pre-REACH and 90 post-REACH individuals. Median age (interquartile range [IQR]) was 35 (25-45) years, 80% were male, 91% black, 60% men who have sex with men, 57% uninsured, and 44% active substance users. TVS decreased from 77 (62-96) to 57 (41-70) days (P < .0022). Time to first attended provider visit decreased from 17 to 5 days, and TAI from 21 to 7 days (P < .0001), each remaining significant in adjusted models.

Conclusions

This is the largest rapid entry cohort described in the United States and suggests that rapid entry is feasible and could have a positive impact on HIV transmission at the population level.

Room for Improvement: The HIV-Diabetes Care Continuum Over 15 Years in the Women's Interagency HIV Study

Background

Gains in life expectancy through optimal control of HIV infection with antiretroviral therapy (ART) may be threatened if other comorbidities, such as diabetes, are not optimally managed.

Methods

We analyzed cross-sectional data of the Women's Interagency HIV Study (WIHS) from 2001, 2006, and 2015. We estimated the proportions of HIV-positive and HIV-negative women with diabetes who were engaged in care and achieved treatment goals (hemoglobin A1c [A1c] <7.0%, blood pressure [BP] <140/90 mmHg, low-density lipoprotein [LDL] cholesterol <100 mg/dL, not smoking) and viral suppression. Repeated-measures models were used to estimate the adjusted prevalence of achieving each diabetes treatment goal at each time point, by HIV status.

Results

We included 486 HIV-positive and 258 HIV-negative women with diabetes. In 2001, 91.8% visited a health care provider, 60.7% achieved the A1c target, 70.5% achieved the BP target, 38.5% achieved the LDL cholesterol target, 49.2% were nonsmokers, 23.3% achieved combined ABC targets (A1c, BP, and cholesterol), and 10.9% met combined ABC targets and did not smoke. There were no differences by HIV status, and patterns were similar in 2006 and 2015. Among HIV-positive women, viral suppression increased from 41% in 2001 to 87% in 2015 compared with 8% and 13% achieving the ABC goals and not smoking. Viral suppression was not associated with achievement of diabetes care goals.

Conclusions

Successful management of HIV is outpacing that of diabetes. Future studies are needed to identify factors associated with gaps in the HIV-diabetes care continuum and design interventions to better integrate effective diabetes management into HIV care.

Improved HIV markers and decreased emergencyroom usage and hospital admission with initiation of a pilot specialty pharmacy at a southeastern Ryan –White –funded clinic over a three year period

Background

Specialty pharmacy (SP) provides timely medication delivery to patients and seeks to improve patient adherence through monthly pharmacist medication therapy management (MTM). Patients living with HIV/AIDS have both high cost medications and complex disease states and thus will benefit from SP. We report on the outcome of HIV therapy after 3 years of a pilot SP ina southern inner city RW funded clinic.

Methods

This is a single center retrospective chart review of patients at our clinic who were enrolled in the SP from 6/3/13–5/1/16 for at least 6 months. Baseline demographic characteristics and HIV markers (CD4, viral load) were collected. Outcomes of interest were: change in CD4 count, percent with viral suppression (VS), emergency room (ER) and hospital admission usage, as well as percent of scheduled providers’ appointment kept. Each individual had the same follow up time before and after SP initiation. Bivariate analysis compared outcomes preSP and during SP using Chi-square or Fisher exact tests for categorical and Wilcoxon rank-sum test for continuous variables.

Results

During the 3-year period, there were 212 individuals referred to SP, of which 170 participated in the program. There were 92(54%) men, 136(80%) black. The median age was 48.3 years (IQR: 28.5–56.3). The average duration of follow up pre and during SP was 22.1(IQR: 16.5–27) months. In terms of insurance, 69(40%) had Medicare, 22(13%) had Medicaid, 22(13%) had private insurance, 54(32%) received AIDS drug Assistance Program (ADAP), and 3(2%) had Ryan White. Patients resided an average distance from the clinic of 17.4(IQR: 8.8–25) miles. The respective outcomes before and during SP were: CD4: 350(IQR: 181–551) vs. 413(IQR: 263–611 cells/mL (P < 0.0001), VS in 78 ± 30% vs. 91 ± 20% (P < 0.0001). The proportion of patients with emergency room usage or hospital admissions was 68(40%) vs. 49(29%) (P = 0.036). There was no difference in the rate of kept providers’ appointment (66.6 %(IQR: 53.8–78.6%) vs. 63.8 %(50-77%) (P = 0.19). There was no reported death during the follow –up period.

Conclusion

This pilot SP program at the RW clinic showed statistically significant improvement of CD4 count and VS, as well as 40 % decrease in odds of using ER or hospital admission. Further studies are needed to determine whether SP is beneficial to people living with HIV/AIDS in other settings.

Disclosures

M. Patel, ViiV: Scientific Advisor, Consulting fee

A Minority of Patients Newly Diagnosed with AIDS Are Started on Antiretroviral Therapy at the Time of Diagnosis in a Large Public Hospital in the Southeastern United States

Prompt antiretroviral therapy (ART) initiation after AIDS diagnosis, in the absence of certain opportunistic infections such as tuberculosis and cryptococcal meningitis, delays disease progression and death, but system barriers to inpatient ART initiation at large hospitals in the era of modern ART have been less studied. We reviewed hospitalizations for persons newly diagnosed with AIDS at Grady Memorial Hospital in Atlanta, Georgia in 2011 and 2012. Individual- and system-level variables were collected. Logistic regression models were used to estimate the odds ratios (ORs) for ART initiation prior to discharge. With Georgia Department of Health surveillance data, we estimated time to first clinic visit, ART initiation, and viral suppression. In the study population (n = 81), ART was initiated prior to discharge in 10 (12%) patients. Shorter hospital stay was significantly associated with lack of ART initiation at the time of HIV diagnosis (8 versus 24 days, OR: 1.14, 95% confidence interval: 1.04-1.25). Reducing barriers to ART initiation for newly diagnosed HIV-positive patients with short hospital stays may improve time to viral suppression.

The Perilous Road from HIV Diagnosis in the Hospital to Viral Suppression in the Outpatient Clinic

The HIV care continuum has received considerable attention in recent years, however, few care continua focus on the population of patients who are diagnosed during an inpatient hospital admission. We aimed to describe the HIV care continuum for patients newly diagnosed during hospitalization through 24-month follow-up. A retrospective chart review of HIV patients diagnosed at Grady Memorial Hospital from 2011 to 2012 was performed and records were matched to Georgia Department of Public Health HIV/AIDS surveillance data. Descriptive statistics and statistical tests of independence were utilized. Ninety-four new diagnoses were confirmed during the 2-year study period. Median age was 43 years (interquartile range [IQR] 30-51), 77% were male, 72% were non-Hispanic Black, 31% were men who have sex with men (MSM), and 77% were uninsured. Median CD4 count at diagnosis was 134 cells/μL (IQR 30-307). Eighty-four percent received their diagnosis before hospital discharge, 68% linked to care by 90 days, 73% were retained for 12 months, 48% were virologically suppressed by 12 months, 58% were retained for 24 continuous months, and 38% achieved continuous viral suppression (VS) during the initial 24 months after diagnosis. Late diagnosis is a persistent problem in hospitalized patients. Despite relative success with linkage to care and 12-month retention in care, a minority of patients maintained retention and VS for 24 continuous months.

Novel Predictors of Poor Retention Following a Down-Referral from a Hospital-Based Antiretroviral Therapy Program in South Africa

Worldwide, HIV care is becoming increasingly decentralized. For patients in care at centralized facilities, this requires down-referral to local clinics for their HIV care. Information on the real-world experience and predictors of retention in care at the time of down-referral is lacking. We sought to evaluate the effect of patient-level factors on retention in care surrounding a period of down-referral to new clinics for patients with and without virologic failure (VF) on their first-line ART. We conducted a secondary analysis of a case-control study of people living with HIV attending the Sinikethemba (SKT) Clinic at McCord Hospital in Durban, South Africa. Cases (VF) and controls (no VF) responded to a questionnaire focused on individual-level factors. Subsequently, participants self-reported either changing service provider (retained in care), were unable to be reached, died or reported not attending a new provider visit (not retained in care). Multivariate logistic regression was conducted with factors associated with not being retained in care in a univariate analysis. In all, 458 patients were enrolled in the parent study (158 cases and 300 controls) with a median age of 38 years old and with 65% women. A total of 436 (95%) participants successfully established care at the down-referral clinic. In the multivariate analysis, not being pleased with the clinic (SKT), lower adherence scores, and shorter duration of ART predicted failure of down-referral. Down-referral was successful even for patients with VF. Individual-level factors could act as predictors for patients at increased risk for poor retention during the down-referral process to a local clinic.

Continuous Retention and Viral Suppression Provide Further Insights Into the HIV Care Continuum Compared to the Cross-sectional HIV Care Cascade

BACKGROUND

The human immunodeficiency virus (HIV) care continuum has become an important tool for evaluating HIV care. Current depictions of the care continuum are often cross-sectional and evaluate retention and viral suppression (VS) in a single year, yet the National HIV/AIDS Strategy calls for programs with long-lasting outcomes.

METHODS

Retrospective chart review of HIV-infected patients enrolled in a large, urban clinic in 2010 followed longitudinally for 36 months. McNemar comparisons and logistic regression analyses were conducted to evaluate covariate association with continuous retention and VS. Generalized estimating equation log-linear models were used to integrate time into the model.

RESULTS

Among 655 patients (77% male, 83% black, 54% men who have sex with men (MSM), 78% uninsured) continuous retention/VS at 12 months (84%/64%), 24 months (60%/48%), and 36 months (49%/39%) showed significant attrition (P < .0001) over time. Continuous retention was associated with prevalent VS at the end of 36 months (adjusted prevalence ratio 3.12; 95% confidence interval [CI], 2.40, 4.07). 12-month retention for black (84%) and nonblack (85%) patients was equivalent, yet fewer blacks (46%) than nonblacks (63%) achieved 36-month continuous retention due to a significant interaction between race and time (aOR 0.75, 95% CI, .59, .95).

CONCLUSIONS

Continuous retention is a critically important measure of long-term success in HIV treatment and the crucial component of successful treatment-as-prevention but is infrequently evaluated. Single cross-sections may overestimate successful retention and virologic outcomes. A longitudinal HIV care continuum provides greater insight into long-term outcomes and exposes disparities not evident with traditional cross-sectional care continua.

Expression divergence of FRUITFULL homeologs enhanced pod shatter resistance in Brassica napus

To improve pod shatter resistance in the important oilseed crop Brassica napus, the phenotypic diversity of B. napus was tested using 80 B. napus varieties for pod shatter resistance by a random impact test. Among these varieties, R1-1 was identified as resistant, while R2, 8908B was susceptible to shatter. To understand the molecular basis for this phenotypic difference based on the candidate gene approach, B. napus FRUITFULL (FUL) homologs were identified and characterized. Two FUL loci in the A and C genomes of B. napus were identified. In the susceptible variety, both BnaA.FUL and BnaC.FUL were expressed in the same tissues. However, the expression level of BnaC.FUL differed in varieties with different pod shatter resistance. In the most resistant variety, R1-1, only BnaA.FUL was expressed, while BnaC.FUL was silenced. Therefore, the functional divergence and differing expression of BnaX.FUL homeologs may significantly affect phenotypic variation, which is an important consequence of allopolyploid evolution. This expression level divergence may be useful for selecting pod shatter resistant lines through marker-assisted selection in B. napus-breeding programs.

A Glimpse of the Early Years of the Human Immunodeficiency Virus Epidemic: A Fellow's Experience in 2014

Human immunodeficiency virus (HIV) is a manageable chronic disease in the United States, yet the first author's experience on a general infectious diseases (ID) consult service illustrates that certain areas of the United States still experience high rates of acquired immune deficiency syndrome-related complications.

Adverse Drug Reactions to Antiretroviral Therapy in HIV-Infected Patients at the Largest Public Hospital in Nicaragua

Objective:

Adverse drug reactions (ADRs) to antiretroviral therapy (ART) are an important cause of hospitalization, treatment discontinuation, and regimen changes in both developed and developing countries. This study is the first to examine and understand ADRs in HIV-infected patients in Nicaragua.

Methods:

A retrospective descriptive study was conducted from May 2010 to March 2011, in a cohort of HIV-infected patients receiving ART at the largest public hospital in Managua, Nicaragua. Patients were identified based on ADRs reporting on a standardized antiretroviral pharmacotherapy form. Subsequently, chart reviews of these patients were performed in order to document the specific ADRs.

Results:

Six hundred ninety-two patients on ART were included. The incidence of ADRs was 6.4% (95% confidence interval [CI] 4.5-8.2). Females demonstrated a higher incidence, that is, 10.2% (95% CI 5.3-15.1, P = .020). Patients treated with combinations of zidovudine (ZDV)/lamivudine (3TC) and emtricitabine (FTC)/tenofovir (TDF) had fewer ADRs ( P < .01) than those using other combinations. Five patients were hospitalized or had a prolonged hospitalization secondary to ADRs, with no mortality attributed to ADR. The most common manifestations of ADRs were central nervous system (20 of 44), gastrointestinal (12 of 44), and dermatologic (8 of 44) reactions. Adverse drug reactions were classified as “likely ADRs” (25 of 44) and “possible ADRs” (19 of 44). No ADRs were preventable.

Conclusion:

Adverse drug reactions most frequently affected the central nervous system. No ADR was life threatening. The frequency of ADRs in this Nicaraguan patient population was less than that reported from other studies in resource-limited settings.

A proposed model for the flowering signaling pathway of sugarcane under photoperiodic control

Molecular analysis of floral induction in Arabidopsis has identified several flowering time genes related to 4 response networks defined by the autonomous, gibberellin, photoperiod, and vernalization pathways. Although grass flowering processes include ancestral functions shared by both mono- and dicots, they have developed their own mechanisms to transmit floral induction signals. Despite its high production capacity and its important role in biofuel production, almost no information is available about the flowering process in sugarcane. We searched the Sugarcane Expressed Sequence Tags database to look for elements of the flowering signaling pathway under photoperiodic control. Sequences showing significant similarity to flowering time genes of other species were clustered, annotated, and analyzed for conserved domains. Multiple alignments comparing the sequences found in the sugarcane database and those from other species were performed and their phylogenetic relationship assessed using the MEGA 4.0 software. Electronic Northerns were run with Cluster and TreeView programs, allowing us to identify putative members of the photoperiod-controlled flowering pathway of sugarcane.

Disparities in HIV-treatment responses between Haitians, African Americans, and Hispanics living in Miami-Dade County, Florida

BACKGROUND

Studies evaluating response to treatment with Highly Active Antiretroviral Therapy (HAART) fail to examine Haitian patients living in the U.S. as a distinct group.

METHODS

This study was designed to determine the effectiveness of HAART in Haitians compared with other minority groups. We conducted a retrospective cohort study of HIV patients from two clinics. The cohort included 96 Hispanics, 60 African Americans, and 49 Haitians, after reviewing a total of 891 charts.

RESULTS

At 96 weeks, fewer Haitians (58.5%) achieved a suppressed viral load than African American (74.1%) or Hispanic (82.8%) patients (p=.021). Median CD4 counts at baseline were lowest among Haitians, with 158 cells/mm3, compared with African Americans, 176 cells/mm3 and Hispanics, 199 cells/mm3.

CONCLUSIONS

Haitians are not doing as well on HAART as other groups. This may be explained by linguistic, cultural, or other barriers that are not currently addressed by the health care system in the United States.

R5 human immunodeficiency virus type 1 infection of fetal thymic organ culture induces cytokine and CCR5 expression

Late-stage CCR5 tropic human immunodeficiency virus type 1 (HIV-1) isolates (R5 HIV-1) can deplete nearly all CD4+ thymocytes from human thymus/liver grafts, despite the fact that fewer than 5% of these cells express CCR5. To resolve this paradox, we studied the replication and cytopathic effects (CPE) of late-stage R5 HIV-1 biological clones from two progressors and two long-term nonprogressors (LTNP) in fetal thymic organ culture (FTOC) with and without added cytokines. We found that R5 HIV-1 clones from progressors but not LTNP were cytopathic in untreated FTOC. Moreover, R5 HIV-1 clones from progressors replicated to higher levels than LTNP-derived R5 HIV-1 clones in this system. In contrast, when FTOC was maintained in the presence of interleukin 2 (IL-2), IL-4, and IL-7, both progressor and LTNP clones exhibited similar replication and CPE, which were equal to or greater than the levels achieved by progressor-derived R5 HIV-1 clones in untreated FTOC. This finding was likely due to IL-2-induced CCR5 expression on CD4+ thymocytes in FTOC. R5 HIV-1 clones showed greater pathogenesis for CCR5+ cells but also showed evidence of CPE on CCR5- cells. Furthermore, infection of FTOC by R5 HIV-1 induced IL-10 and transforming growth factor beta (TGF-beta) expression. Both IL-10 and TGF-beta in turn induced CCR5 expression in FTOC. Induction of CCR5 expression via cytokine induction by R5 HIV-1 infection of CCR5+ thymocytes likely permitted further viral replication in newly CCR5+ thymocytes. CCR5 expression, therefore, is a key determinant of pathogenesis of R5 HIV-1 in FTOC.

'Florigen' enters the molecular age: long-distance signals that cause plants to flower

The transition from vegetative to reproductive growth is a critical event in the life cycle of plants. Previous physiological studies have deduced that hormone-like substances mediate this important transition but the biochemical nature of the putative signaling molecules has remained elusive. Recent molecular and genetic studies of key flowering-time genes offer new approaches to understanding the mechanisms underlying the initiation of flowering.

A floret by any other name: control of meristem identity in maize

The life of a plant unfolds as a series of developmental stages, with each stage defined by changes in meristem identity. In maize, there are several distinct stages: the transition from vegetative growth to flowering, the elaboration of the inflorescence, and the formation of flowers. Progress in understanding meristem identity and function has been made by analyzing maize mutants with defects at each of these stages. Recently cloned genes suggest that, although the molecular mechanisms controlling floral organ identity are conserved in maize and other model species, the control of meristem identity during earlier developmental stages might be less conserved.

The indeterminate gene encodes a zinc finger protein and regulates a leaf-generated signal required for the transition to flowering in maize

Flowering in plants is a consequence of the transition of the shoot apex from vegetative to reproductive growth in response to environmental and internal signals. The indeterminate1 gene (id1) controls the transition to flowering in maize. We show by cloning the id1 gene that it encodes a protein with zinc finger motifs, suggesting that the id1 gene product functions as a transcriptional regulator of the floral transition. id1 mRNA expression studies and analyses of transposon-induced chimeric plants indicate that id1 acts non-cell-autonomously to regulate the production of a transmissible signal in the leaf that elicits the transformation of the shoot apex to reproductive development. These results provide molecular and genetic data consistent with the florigen hypothesis derived from classical plant physiology studies.

Cloning of four cyclins from maize indicates that higher plants have three structurally distinct groups of mitotic cyclins

While a large number of cyclins have been described in animals and yeasts, very limited information is available regarding cyclins in plants. We describe here the isolation of cDNA clones encoding four putative mitotic cyclins from maize. All four cyclins were able to induce maturation of Xenopus oocytes, demonstrating that they can act as mitotic cyclins in this system. Northern analysis showed that all four cyclins were expressed only in actively dividing tissues and organs, with a stronger correlation between expression and mitotic activity than is observed with cdc2. The deduced protein sequences suggest that the four maize cyclins belong to the cyclin A and B families identified from animal and yeast studies but that they cannot be described easily as either A-type or B-type cyclins. However, comparison with previously cloned plant cyclins shows that cyclins in higher plants form three distinct structural groups that have been conserved in both monocotyledonous and dicotyledonous species and that cyclins from all three groups are present within a single plant species.

Localization of the Functional p34cdc2 Homolog of Maize in Root Tip and Stomatal Complex Cells: Association with Predicted Division Sites

We have used an antibody against the functional homolog of the cdc2 kinase of maize to localize the p34cdc2 protein within dividing cells of the root apex and the stomatal complex of leaf epidermis. The microtubule cytoskeletal structure of plant cells was visualized concomitantly with a monoclonal antibody specific for [alpha]-tubulin. We found that the cdc2 protein is localized mainly to the nucleus in plant cells at interphase and early prophase. This finding contrasts markedly with the predominantly cytoplasmic staining obtained using antibody to the PSTAIRE motif, which is common to cdc2 and numerous cdc2-like proteins. In a subpopulation of root cells at early prophase, the p34cdc2 protein is also distributed in a band bisecting the nucleus. Double labeling with the maize p34cdc2Zm antibody and tubulin antibody revealed that this band colocalizes with the preprophase band (PPB) of microtubules, which predicts the future division site. Root cells in which microtubules had been disrupted with oryzalin did not contain this band of p34cdc2 protein, suggesting that formation of the microtubule PPB is necessary for localization of the p34cdc2 kinase to the plane of the PPB. The p34cdc2 protein is also localized to the nucleus and PPB in cells that give rise to the stomatal complex, including those cells preparing for the highly asymmetrical divisions that produce subsidiary cells. Association of the p34cdc2 protein with the PPB suggests that the cdc2 kinase has a role in establishing the division site of plant cells and, therefore, a role in plant morphogenesis.

Isolation and characterization of cDNA clones encoding a functional p34cdc2 homologue from Zea mays

We describe the isolation of cDNA clones encoding a p34cdc2 homologue from a higher plant, Zea mays (maize). A full-length cDNA clone, cdc2ZmA, was isolated, sequenced, and shown to complement a cdc28 mutation in Saccharomyces cerevisiae. Comparison of the deduced amino acid sequence of the maize p34cdc2 protein with other homologues showed that it was 64% identical to human p34cdc2 and 63% identical to Schizosaccharomyces pombe and S. cerevisiae p34cdc2 proteins. Studies of expression of the maize cdc2 gene(s) by Northern blot analysis indicated a correlation between the abundance of cdc2 mRNA and the proliferative state of the tissue. Southern blot analysis, as well as isolation of another cDNA clone, cdc2ZmB, which is 96% identical to cdc2ZmA, indicates that maize has multiple cdc2 genes.

Cytosine methylated DNA synthesized by Taq polymerase used to assay methylation sensitivity of restriction endonuclease HinfI

We have studied the resistance of cytosine methylated DNA to digestion by the restriction endonuclease HinfI, using a simple PCR procedure to synthesize DNA of known sequence in which every cytosine is methylated at the 5 position. We find that HinfI cannot digest cytosine methylated DNA at the concentrations normally used in restriction digests. Complete digestion is possible using a vast excess of enzyme; under these conditions, the rate of HinfI digestion for cytosine methylated DNA is at least 1440-fold slower than for unmethylated DNA. The presence of an additional methylated cytosine at the degenerate position internal to the recognition sequence does not appear to increase the resistance to HinfI digestion. We also tested HhaII, an isoschizomer of HinfI, and found that it is completely inactive on cytosine methylated DNA. The procedure we have used should be of general applicability in determination of the methylation sensitivities of other restiction enzymes, as well as studies of the effects of methylation on gene expression in direct DNA transfer experiments.

Mechanism of replication of bacteriophage phi X174. XXII. Site-specific mutagenesis of the A* gene reveals that A* protein is not essential for phi X174 DNA replication

The A and A* proteins of phage phi X174 are encoded in the same reading frame in the viral genome; the smaller A protein is the result of a translational start signal with the A gene. To differentiate their respective functions, oligonucleotide-directed site-specific mutagenesis was used to change the ATG start codon of the phi X 174 A* gene, previously cloned into pCQV2 under lambda repressor control, into a TAG stop codon. The altered A gene was then inserted back into phi X replicative form DNA to produce an amber mutant, phi XamA*. Two different Escherichia coli amber suppressor strains infected with this mutant produced viable progeny phage with only a slight reduction in yield. In Su+ cells infected with phi XamA*, phi X gene A protein, altered at one amino acid, was synthesized at normal levels; A* protein was not detectable. These observations indicate that the A* protein increases the replicative efficiency of the phage, perhaps by shutting down host DNA replication, but is not required for replication of phi X174 DNA or the packaging of the viral strand under the conditions tested.

The Escherichia coli rep mutation. X. Consequences of increased and decreased Rep protein levels

Recombinant DNA techniques were used to study various aspects of rep gene function in Escherichia coli. In order to enhance expression of the Rep protein, the rep gene was cloned into the vector pKC30 under the control of the lambda pL promoter. By trimming away a portion of the DNA sequence immediately upstream of the translational start site of rep, we were able to obtain very high levels of Rep protein upon induction. Cells carrying such plasmids showed no ill effects from the high concentration of the protein. To ascertain the consequence of the absence of Rep protein on the cell, the chromosomal copy of the gene was deleted using a homologous recombination technique. The viability of E. coli strains completely lacking the rep gene proves that the Rep function is not essential, at least in wild-type cells under laboratory conditions. We confirmed that in the absence of Rep function there is an increase in the average number of growing forks in exponentially growing cells; augmentation of Rep protein levels above normal, however, did not detectably decrease the number of growing forks.

Expression of the cloned bacteriophage phi X174 A* gene in Escherichia coli inhibits DNA replication and cell division

The A* gene of bacteriophage phi X174 has been cloned into the inducible expression vector pCQV2 under conditions allowing its lethal action to be controlled by the lambda cI857 repressor. Upon induction of expression, DNA synthesis in Escherichia coli carrying the recombinant plasmid is severely inhibited; however, these same cells permit beta-galactosidase induction at a rate similar to that observed in control cells at the inducing (for A*) temperature. Cells in which A* is expressed form filaments and produce more RecA protein, indicating at least a partial induction of the SOS response; however, there is no evidence of damage to the bacterial chromosome. It appears that the A* protein has as one function the inhibition of cell division and DNA replication but not transcription or protein synthesis during phage infection.