Rational Design, Synthesis, and Biological Evaluation of Heterocyclic Quinolones Targeting the Respiratory Chain of Mycobacterium tuberculosis

A high-throughput screen (HTS) was undertaken against the respiratory chain dehydrogenase component, NADH:menaquinone oxidoreductase (Ndh) of Mycobacterium tuberculosis (Mtb). The 11000 compounds were selected for the HTS based on the known phenothiazine Ndh inhibitors, trifluoperazine and thioridazine. Combined HTS (11000 compounds) and in-house screening of a limited number of quinolones (50 compounds) identified ∼100 hits and four distinct chemotypes, the most promising of which contained the quinolone core. Subsequent Mtb screening of the complete in-house quinolone library (350 compounds) identified a further ∼90 hits across three quinolone subtemplates. Quinolones containing the amine-based side chain were selected as the pharmacophore for further modification, resulting in metabolically stable quinolones effective against multi drug resistant (MDR) Mtb. The lead compound, 42a (MTC420), displays acceptable antituberculosis activity (Mtb IC₅₀ = 525 nM, Mtb Wayne IC₅₀ = 76 nM, and MDR Mtb patient isolates IC₅₀ = 140 nM) and favorable pharmacokinetic and toxicological profiles.

In Vitro Activity of Bedaquiline against Nontuberculous Mycobacteria in China

The main goal of our study was to evaluate the in vitro bedaquiline susceptibility of six prevalent species of pathogenic nontuberculous mycobacteria (NTM) in China. In addition, we investigated the potential molecular mechanisms contributing to bedaquiline resistance in the different NTM species. Among slowly growing mycobacteria (SGM), bedaquiline exhibited the highest activity against Mycobacterium avium; the MIC₅₀ and MIC₉₀ values were 0.03 and 16 mg/liter, respectively. Among rapidly growing mycobacteria (RGM), Mycobacterium abscessus subsp. abscessus (M. abscessus) and Mycobacterium abscessus subsp. massiliense (M. massiliense) seemed more susceptible to bedaquiline than Mycobacterium fortuitum, with MIC₅₀ and MIC₉₀ values of 0.13 and >16 mg/liter, respectively, for both species. On the basis of bimodal distributions of bedaquiline MICs, we proposed the following epidemiological cutoff (ECOFF) values: 1.0 mg/liter for SGM and 2.0 mg/liter for RGM. Among M. avium, Mycobacterium intracellulare, Mycobacterium kansasii, M. abscessus, M. massiliense, and M. fortuitum isolates, 14 (29.8%), 41 (27.2%), 33 (39.3%), 44 (20.2%), 42 (25.8%), and 7 (31.8%), respectively, were resistant to bedaquiline. No significant differences in the proportions of bedaquiline resistance among these species were observed (P > 0.05). Genetic mutations were observed in 74 isolates (10.8%), with all nucleotide substitutions being synonymous. In conclusion, our data demonstrate that bedaquiline shows moderate in vitro activity against NTM species. Using the proposed ECOFF values, we could distinguish between bedaquiline-resistant and -susceptible strains with the broth dilution method. In addition, no nonsynonymous mutations in the atpE gene that conferred bedaquiline resistance in all six NTM species were identified.

Household food insecurity among people living with HIV in Sagamu, Nigeria: A preliminary study

BACKGROUND

Household food insecurity has been associated with increased risk of transmission of HIV infection and poor treatment outcomes. This study therefore determined the prevalence of household food insecurity and its associated factors among people living with HIV in Sagamu, Ogun State, Nigeria.

METHODS

A cross-sectional descriptive study was carried out among 244 adult clients accessing care and support at the teaching hospital in Sagamu, Nigeria, selected via systematic sampling. Data was collected with the aid of a semi-structured, interviewer-administered questionnaire. Data was analysed using SPSS 21.0. Relevant descriptive and inferential statistics were calculated. Informed consent was obtained and strict confidentiality was ensured.

RESULTS

The mean age of respondents was 38.8 ± 9.2 years; 84% of respondents were female; 69.3% were married, 12.9% had lost their partners. About 12% spent more than three-quarters of the household income on food. The prevalence of household food insecurity was 71.7%. Food insecurity was associated ( p < 0.05) with educational status; occupation; type of housing; availability of toilet facilities; benefiting from food assistance; delaying drugs to prevent hunger; skipping drugs; vegetable consumption pattern; and exchanging sex for food.

CONCLUSION

The prevalence of household food insecurity in this study was high. Living conditions were significantly associated with food insecurity. Socio-economic conditions need to be improved, to optimize the health and food security status of people living with HIV in Sagamu.

Successful Withdrawal of Insulin Therapy After Post-Treatment Clearance of Hepatitis C Virus in a Man with Type 2 Diabetes

Patient: Male, 55

Final Diagnosis: Hepatitis C

Symptoms: Icterus

Medication: —

Clinical Procedure: —

Specialty: Endocrinology and Metabolic

Persistent arthralgia and related risks factors in laboratory-confirmed cases of Chikungunya virus infection in Mexico

Objective.

To estimate the cumulative incidence of persistent arthralgia at 6 months from acute Chikungunya virus (CHIKV) infection and to evaluate the association of clinical markers with the risk of long-term arthralgia.

Methods.

This multicenter retrospective cohort study was conducted in the Mexican state of Colima. A total of 136 individuals aged 15 years and older with serologically confirmed CHIKV infection were enrolled. Participants were interviewed at 6 months from the onset of symptoms, and self-reported persistent arthralgia (PA) was the main binary outcome. A self-report numeric rating scale (NRS) ranging from 0 to 10 was used to estimate the severity of articular pain.

Results.

The cumulative incidence of PA was 41.9%. Severe pain (NRS ≥ 7) presented in 36.8% of participants with PA. In multiple analysis, individuals aged 40 years and older (risk ratio (RR) = 1.60; 95% confidence interval (CI), 1.03-2.48) and those with articular pain at 3 months post-infection (RR = 3.95; 95% CI, 1.95-8.01) had a significantly increased risk of PA at 6 months from CHIKV infection.

Conclusions.

To the best of our knowledge, this is first report of a CHIKV-associated longterm outcome in Mexico, where the incidence of the infection has been high. This is also the first study in Latin America evaluating several factors associated with the risk of PA. Our findings may be useful in health care settings to stratify the risk of chronic arthralgia secondary to CHIKV infection and to identify patients who would benefit clinically from early medical intervention.

Therapeutic Inhibition of Complement: Well Worth the Risk

Complement is an integral part of the immune system and protects against infection. Complement-mediated immunopathology in many autoimmune diseases and syndromes has led to the therapeutic targeting of complement and to questions around the safety of complement inhibition. Here; I examine and clarify the risks associated with complement therapeutics.

Pitavastatin versus pravastatin in adults with HIV-1 infection and dyslipidaemia (INTREPID): 12 week and 52 week results of a phase 4, multicentre, randomised, double-blind, superiority trial

BACKGROUND

People living with HIV-1 infection are at greater risk for cardiovascular disease than seronegative adults. Treatment of dyslipidaemia with statins has been challenging in people with HIV because of an increased potential for drug interactions due to competing cytochrome P450 metabolism between statins and commonly used antiretroviral agents. Neither pitavastatin nor pravastatin depend on cytochrome P450 for primary metabolism. We aimed to assess the safety and efficacy of pitavastatin versus pravastatin in adults with HIV and dyslipidaemia.

METHODS

In the INTREPID (HIV-infected patieNts and TREatment with PItavastatin vs pravastatin for Dyslipidemia) randomised, double-blind, active-controlled, phase 4 trial (INTREPID, we recruited adults aged 18-70 years with controlled HIV (with CD4 counts >200 cells per μL and HIV-1 RNA <200 copies per mL) on antiretroviral therapy for at least 6 months and dyslipidaemia (LDL cholesterol 3·4-5·7 mmol/L and triglycerides ≤4·5 mmol/L) from 45 sites in the USA and Puerto Rico. Patients being treated with darunavir, or who had homozygous familial hypercholesterolaemia or any condition causing secondary dyslipidaemia, or a history of statin intolerance, diabetes, or coronary artery disease were not eligible. We randomly assigned patients (1:1) to pitavastatin 4 mg or pravastatin 40 mg with matching placebos once daily orally for 12 weeks, followed by a 40 week safety extension. Randomisation was stratified by viral hepatitis B or C coinfection and computer-generated. Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. The primary endpoint was percentage change in fasting serum LDL cholesterol from baseline to week 12 and the primary efficacy analysis was done in the modified intention-to-treat population. The safety analysis included all patients who took at least one dose of study medication. This study is registered with ClinicalTrials.gov, number NCT01301066.

FINDINGS

Between Feb 23, 2011, and March 29, 2013, we randomly assigned 252 patients to the pitavastatin (n=126) or pravastatin group (n=126). LDL cholesterol reduction was 31·1% with pitavastatin and 20·9% with pravastatin (least squares mean difference -9·8%, 95% CI -13·8 to -5·9; p<0·0001) at 12 weeks. At week 52, four patients (3%) in the pitavastatin group and six (5%) in the pravastatin group had virological failure, with no significant difference between treatments. Both treatments had neutral effects on glucose metabolism parameters. 85 patients treated with pitavastatin (68%) and 88 patients treated with pravastatin (70%) reported treatment-emergent adverse events, and these caused study discontinuation in six patients (5%) versus five patients (4%). No serious adverse event occurred in more than one participant and none were treatment-related according to investigator assessment. The most common treatment-emergent adverse events were diarrhoea in the pitavastatin group (n=12, 10%) and upper respiratory tract infection in the pravastatin group (n=14, 11%). 11 treatment-emergent serious adverse events were noted in seven patients (6%) in the pitavastatin group (atrial septal defect, chronic obstructive pulmonary disease, chest pain, diverticulitis, enterovesical fistula, gastroenteritis, viral gastroenteritis, herpes dermatitis, multiple fractures, respiratory failure, and transient ischaemic attack) and four events in three patients (2%) in the pravastatin group (cerebrovascular accident, arteriosclerosis coronary artery, myocardial infraction, and muscle haemorrhage). In the pravastatin treatment group, one additional patient discontinued due to an adverse event (prostate cancer that was diagnosed during the screening period, 42 days before first dose of study treatment, and therefore was not a treatment-emergent adverse event).

INTERPRETATION

The INTREPID results support guideline recommendations for pitavastatin as a preferred drug in the treatment of dyslipidaemia in people with HIV.

FUNDING

Kowa Pharmaceuticals America and Eli Lilly and Company.

Impact of a multifaceted antimicrobial stewardship program: A front-line ownership driven quality improvement project in a large urban emergency department

BACKGROUND

Antibiotic overuse has promoted growing rates of antimicrobial resistance and secondary antibiotic-associated infections such as Clostridium difficile (C. difficile). Antimicrobial stewardship programs (ASPs) are effective in reducing antimicrobial use in the inpatient setting; however, the unique environment of the emergency department (ED) lends itself to challenges for successful implementation. Front-line ownership (FLO) methodology has been shown to be a potentially effective strategy for the implementation of inpatient ASPs through an iterative multi-pronged approach driven by front-line providers.

OBJECTIVE

To determine whether a FLO approach to antimicrobial stewardship in the ED can alter antimicrobial usage.

METHODS

Interventions were driven by ED physicians and facilitated by Infectious Diseases Division physicians from the hospital's ASP using FLO principles. Measured end points included antibiotic usage in the ED as measured by defined daily doses, and rates of urine culture sent from the ED.

RESULTS

There was a step-wise significant reduction in the use of azithromycin (p=0.006), ceftriaxone (p=0.045), ciprofloxacin (p=0.034), and moxifloxacin (p=0.008). There was also a significant reduction in rates of urine cultures (p<0.001) by 2.26 urine cultures per 100 ED patient visits.

CONCLUSIONS

FLO offers a promising approach to successful implementation of an ASP in the ED. Future studies would be important to evaluate the generalizability of the FLO approach to ASP development in other EDs and to determine strategies to improve the sustainability of reductions in antimicrobial use.

Analysis of novel meningococcal vaccine formulations

The protective effect of meningococcal vaccines targeting disease causing serogroups exemplified by the introduction of MenAfriVac™ in Africa, is well established and documented in large population-based studies. Due to the emergence of other meningococcal disease causing serogroups, novel vaccine formulations are needed. There is a high potential for novel nanotechnology-based meningococcal vaccine formulations that can provide wider vaccine coverage. The proposed meningococcal vaccine formulation contains spherical shaped micro and nanoparticles that are biological mimics of Niesseria meningitidis, therefore present to immune system as invader and elicit robust immune responses. Vaccine nanoparticles encapsulate meningococcal CPS polymers in a biodegradable material that slowly release antigens, therefore enhance antigen presentation by exerting antigen depot effect. The antigenicity of meningococcal vaccine delivered in nanoparticles is significantly higher when compared to vaccine delivered in solution. Preclinical studies are required to assess the immunogenicity of novel vaccine formulations. Therefore, implementing various in-vitro human immune cell-based assays that mimic in-vivo interactions, would provide good insight on optimal antigen dose, effective antigen presentation, facilitate screening of various vaccine and adjuvant combinations and predict in-vivo immunogenicity. This rapid approach is cost-effective and provides data required for the preclinical immunogenicity assessment of novel meningococcal vaccine formulations.

Novel specific markers for hepatocellular carcinoma: Perspective on clinical applications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Despite continuous global efforts aimed at HCC eradication and improvements in various treatment techniques, the prognosis of HCC remains very poor. How to monitor malignant transformation of hepatocytes or diagnose HCC at early stage is still a medical challenge. A growing understanding of the multiple pathogenic factors including hepatitis B virus or hepatitis C virus infection, lipid accumulation, aflatoxin B1 intake and so on suggests that hepatocarcinogenesis is a multistep process. A large number of oncogenes or tumor suppressor genes have been identified. Early screening of HCC patients has been reported to confer a survival benefit. Although serum alpha-fetoprotein (AFP) and hepatoma-specific AFP have been used as conventional tumor markers, they often show false-positive results and lack sufficient sensitivity and specificity. In order to provide optimal treatment for each patient with HCC, more precise and effective biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis evaluation. Recently, numerous studies have shown the clinical utility of novel blood-based biomarkers, such as circulating tumor cells, key signal molecules or specific proteins, long non-coding RNAs, and microRNAs. In this article, we will review some novel HCC-related biomarkers and discuss their future perspective on clinical applications.

Efficacy of palivizumab prophylaxis on the frequency of RSV-associated lower respiratory tract infections in preterm infants: determination of the ideal target population for prophylaxis

Respiratory syncytial virus (RSV) prophylaxis in high-risk infants is an effective intervention for the prevention of severe disease. The aim of this study was to determine the ideal target preterm population that might benefit from palivizumab prophylaxis by establishing the main risk factors for acute RSV-related infections. Former premature infants born with a gestational age ≤37 weeks and ≤1 year of age at the beginning of the RSV season and admitted with respiratory infection were included. RSV status was evaluated by RSV strip test in all infants. RSV-positive and -negative infants were compared in terms of demographic features, risk factors, requirement of hospitalisation and palivizumab administration. A total of 202 preterm infants under 1 year of age were enrolled. The RSV test was positive in 34 (16.8%) infants. Maternal age was significantly lower in RSV-positive infants compared with RSV-negative infants (p = 0.03). RSV-positive infants were found to be significantly discharged during the RSV season (p = 0.03). RSV-positive infants required significantly higher rates of hospitalisation and need for mechanical ventilation. Of the RSV-positive infants, 28 (82%) had a gestational age ≥29 weeks. Seventeen (77%) RSV-positive infants that required hospitalisation were ≥29 weeks of gestation. All infants with a gestational age ≥29 weeks and without palivizumab prophylaxis developed RSV infection. Palivizumab prophylaxis should be implemented into guidelines to cover preterm infants with a gestational age >29 weeks. Palivizumab prophylaxis should also be considered in high-risk infants ≤6 months of age during the RSV season.

In vitro activity of fosfomycin trometamol and other oral antibiotics against multidrug-resistant uropathogens

Clinical midstream and urinary catheter isolates (n = 106) of extended-spectrum β-lactamase (ESBL)-positive Escherichia coli, Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae, Proteus mirabilis and meticillin-resistant Staphylococcus saprophyticus were tested against fosfomycin using the agar dilution method, the broth microdilution method and the gradient test described by the Clinical and Laboratory Standards Institute. Nitrofurantoin, co-trimoxazole, amoxicillin/clavulanic acid, cefuroxime, levofloxacin and ciprofloxacin were tested using the gradient test alone. Breakpoints from the European Committee on Antimicrobial Susceptibility Testing 2015 guidelines were used. Fosfomycin inhibited all of the ESBL-positive E. coli, P. mirabilis and meticillin-resistant S. saprophyticus strains isolated from urine, as well as 82% of KPC-producing K. pneumoniae isolates. Substantial agreement for fosfomycin activity was found for the three test methods, particularly for Enterobacteriaceae. This study confirmed that fosfomycin has good in vitro activity against more common multidrug-resistant uropathogens. Fosfomycin could be a reliable empirical therapeutic option for uncomplicated urinary tract infections caused by these organisms, and a valid option for sparing parenteral antibiotics, such as carbapenems.

Antibiotic Resistance Profiles and Genotypes of Acinetobacter baumannii Isolates and In Vitro Interactions of Various Antibiotics in Combination with Tigecycline and Colistin

Objectives

The aim of this study was to determine the antibiotic resistance profile, clonal relation and efficacy of antibiotic combinations in nosocomial multidrug resistant (MDR) Acinetobacter baumannii.

Materials and Methods

Antibiotic susceptibilities of 84 MDR A. baumannii against tigecycline (TGC), colistin (CL), amikacin (AK), ciprofloxacin (CIP), meropenem (MR), moxifloxacin (MXF), rifampicin (RF) were determined by microdilution method. Clonal relationship was investigated by genotyping using AP-PCR and antibiotyping. Interactions of antibiotic combinations were tested against clonally unrelated strains by the checkerboard (CB) method. The efficacy of the best combinations was also assesed on a selected isolate by the time-kill (TK) method.

Results

CIP, RF, MXF, MR, AK resistance was found as 90.47%; 47.62%; 22.62%; 58.33%; 50% respectively; however; CL and TGC were not ascertained. The isolates were distinguished as 25 different antibiotypes and 15 varied molecular patterns. The best synergistic effect was detected in combinations of CL with RF (100%) and MR (100%), in combinations of TGC with RF (53%) against clonally unrelated 15 MDR A. baumannii isolates by the CB method. While CL-RF and CL-MR showed synergy by TK method like CB, on the other hand TGC-RF indicated additive interactions by TK.

Conclusion

In this study, both synergy tests showed that CL in combination with RF would be a good option in MDR A. baumannii.

Modeling the cost-effectiveness of infant vaccination with pneumococcal conjugate vaccines in Germany

BACKGROUND

In 2009, the European Medicines Agency granted approval for two higher-valent pneumococcal conjugate vaccines. This study aims to evaluate the cost-effectiveness of universal infant (<2 years old) vaccination with a 13-valent pneumococcal conjugate vaccine (PCV13) in comparison with a 10-valent pneumococcal conjugate vaccine (PCV10) for the prevention of pneumococcal disease in Germany.

METHODS

A population-based Markov model was developed to estimate the impact of PCV13 and PCV10 on invasive pneumococcal disease (IPD), non-invasive pneumonia (PNE), and acute otitis media (AOM) over a time horizon of 50 years. The model included the effects of the historical vaccination scheme in infants as well as indirect herd effects and replacement disease. We used German epidemiological data to calculate episodes of IPD, PNE, and AOM, as well as direct and indirect effects of the vaccination. Parameter uncertainty was tested in univariate and probabilistic sensitivity analyses.

RESULTS

In the base-case analysis, the ICER of PCV13 versus PCV10 infant vaccination was EUR 9826 per quality-adjusted life-year (QALY) gained or EUR 5490 per life-year (LY) gained from the societal perspective and EUR 3368 per QALY gained or EUR 1882 per LY gained from the perspective of the German statutory health insurance. The results were particularly sensitive to the magnitude of indirect effects of both vaccines.

CONCLUSIONS

Universal infant vaccination with PCV13 is likely to be a cost-effective intervention compared with PCV10 within the German health care system, if additional net indirect effects of PCV13 vaccination are significant.

The immunogenicity and safety of a Hib-MenAC vaccine: a non-inferiority randomized, observer-blind trial in infants aged 3-5 months

BACKGROUND

The objective of this study was to evaluate the immunogenicity and safety of the novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroup A and C-tetanus toxoid conjugate vaccine (Hib-MenAC).

METHODS

We conducted a non-inferiority, randomized, observer-blind, positive control clinical trial in 900 healthy infants aged between 3-5 months in Funing County, Jiangsu Province, China. Participants were randomly allocated, in a ratio of 2:1 (block = 6), to receive experimental combined Hib-MenAC vaccines co-administrated with placebo or the co-administration of licensed Hib vaccine and MenAC vaccine, according to a three-dose immunization schedule. The seroconversion of antibody titer against meningococcal serogroups A, C and Hib was the primary endpoint.

RESULTS

The experimental vaccines was non-inferior to the licensed two control vaccines. Participants receiving experimental Hib-MenAC vaccines showed a seroconversion rate of 99.0%, 96.1% and 97.7% for rSBA-MenA, rSBA-MenC and anti-PRP antibodies, respectively. The Hib-MenAC vaccine did not result in an increase in adverse reaction, and no serious adverse event was judged to be related to the vaccination.

CONCLUSIONS

The novel combined Hib-MenAC conjugate vaccine was safe and highly immunogenic in infants aged between 3 to 5 months.

Advances in Rapid Identification and Susceptibility Testing of Bacteria in the Clinical Microbiology Laboratory: Implications for Patient Care and Antimicrobial Stewardship Programs

Early availability of information on bacterial pathogens and their antimicrobial susceptibility is of key importance for the management of infectious diseases patients. Currently, using traditional approaches, it usually takes at least 48 hours for identification and susceptibility testing of bacterial pathogens. Therefore, the slowness of diagnostic procedures drives prolongation of empiric, potentially inappropriate, antibacterial therapies. Over the last couple of years, the improvement of available techniques (e.g. for susceptibility testing, DNA amplification assays), and introduction of novel technologies (e.g. MALDI-TOF) has fundamentally changed approaches towards pathogen identification and characterization. Importantly, these techniques offer increased diagnostic resolution while at the same time shorten the time-to-result, and are thus of obvious importance for antimicrobial stewardship. In this review, we will discuss recent advances in medical microbiology with special emphasis on the impact of novel techniques on antimicrobial stewardship programs.

A Pilot Study for Antimicrobial Stewardship Post-Discharge: Avoiding Pitfalls at the Transitions of Care

PURPOSE

Lack of patient follow-up is a major concern during care transitions, and the role of an antimicrobial stewardship program (ASP) in assessing antimicrobial regimens after hospital discharge is not well described. We implemented an expanded ASP to include patients recently discharged from the hospital and measured its impact on inappropriate antimicrobial therapy 72 hours after inpatient culture data were finalized.

METHODS

A prospective cohort study was conducted at a 583-bed tertiary care center in the Upper Midwest of America. All patients discharged from our facility on antimicrobial therapy with pending culture results between February 3, 2016, and March 2, 2016, were included for review. If a pathogen nonsusceptible to all prescribed antimicrobials was identified post-discharge, a recommendation for therapy modification was communicated to the prescriber.

RESULTS

Thirty-eight patients discharged from our hospital on antimicrobial therapy with pending culture results were evaluated for intervention. When final culture susceptibilities were considered, 5 of 38 patients had been prescribed an inappropriate antimicrobial agent. An ASP pharmacist intervened on 4 of 5 patients, resulting in 3 of 5 patients transitioning to appropriate antimicrobial therapy. When compared to a historical cohort, our transitions-of-care ASP yielded a 3.6-fold increase in antimicrobial-related interventions among discharged patients while reducing inappropriate outpatient antimicrobial therapy by 39%.

CONCLUSION

We believe this is the first pharmacist-driven ASP represented in the medical literature which evaluated all available inpatient culture data to serve patients discharged from the hospital. Antimicrobial stewardship for patients in care transitions may provide an opportunity to increase ASP interventions and reduce inappropriate antimicrobial therapy.

Comparison of anti-pertussis toxin ELISA and agglutination assays to assess immune responses to pertussis

BACKGROUND

The goal of our study was to compare the following two methods of assessment of pertussis post-vaccination immunity: bacterial agglutination test and pertussis toxin enzyme-linked immunosorbent assay (ELISA).

METHODS

The study was carried out in Perm Region, Russia. We measured pertussis immunity using two serological methods: ELISA of IgG to pertussis toxin (PT) and the agglutination test (AT) among 135 children, in the age range from 2 months to 17 years old. The immunization schedule included four doses of DTwP: at 3, 4.5 and 6 months of age and a booster at 18 months. All participants were divided into six age groups.

RESULTS

The percentage of samples with IgG level less than the detection limit in vaccinated children was 52.2%. The total seropositivity rate (the percent of children with agglutinin titres ≥1:160) in vaccinated children was 47.8%. Only a weak association was observed between agglutinin and anti-PT IgG titres (R = .3). Neither the primary nor the booster vaccination with DTwP influenced the IgG levels in children. Agglutinin titres significantly increased after vaccination and declined 5 years after the booster dose. Significant growth of IgG concentration was observed in 11-year-olds, indicating the presence of B. pertussis circulation in the childhood population.

CONCLUSIONS

Based on the obtained results and the results of other authors, we summarize that anti-PT ELISA should be carefully used to assess the population immunity to pertussis. Currently, there is neither a serological test that accurately determines the protection against pertussis nor a distinctive criterion of protection that can be applied in seroepidemiological studies.

Human Coronavirus-HKU1 Infection Among Adults in Cleveland, Ohio

BACKGROUND

Human coronaviruses (CoV) have been long recognized as a common cause of respiratory tract disease including severe respiratory tract illness. Coronavirus-HKU1 has been described predominantly among children less than 5 years of age in the United States with few studies characterizing the disease spectrum among adults.

METHODS

Nasopharyngeal specimens of patients with respiratory symptoms were analyzed for CoV-HKU1 by NxTAG Respiratory Pathogen Panel multiplex assay from February 7, 2016 to April 30, 2016. Epidemiologic, clinical, and laboratory data were collected on adults (patients >18 years) whose samples screened positive.

RESULTS

Of 832 adult respiratory specimens screened, 13 (1.6%) cases of CoV-HKU1 were identified. Adults age ranged between 23 and 75 years and 6 (46%) were males. All of whom had 1 or more respiratory symptoms, and 5 (38%) also reported 1 or more gastrointestinal symptoms. Eleven (85%) reported history of smoking and 5 (38%) used inhaled steroids. Seven (54%) required hospitalization, 5 (71%) of these needed supplemental oxygen, and 2 (29%) were admitted to intensive care. Median length of hospitalization was 5 days. Eight (62%) received antibiotics despite identification of CoV-HKU1. Infectious work-up in 1 patient who died did not reveal any other pathogen. In 2 (15%) CoV-HKU1-positive adults, the only viral coinfection detected was influenza A.

CONCLUSIONS

Coronavirus-HKU1 accounted for 1.6% of adult respiratory infections and should be considered in differential diagnosis of severe respiratory illnesses among adults.

[Advances in diagnostic microbiology : Opportunities and limitations]

In the light of ever increasing problems related to the emergence of multidrug-resistant bacteria, rapid microbiological diagnostics are of growing importance. Timely pathogen detection and availability of susceptibility data are essential for optimal treatment, but are even more crucial for de-escalation of broad spectrum empiric therapies. Medical microbiology is, thus, an integral part of antimicrobial stewardship programs. Traditional microbiological techniques for species identification and susceptibility testing rely on bacterial growth and are, thus, characterized by inherent slowness. Time-to-report is usually 48 h or longer, and typically delays optimization of therapeutic regimens. Constant improvement of available techniques (e. g., molecular methods) and introduction of novel methods (e. g., matrix-assisted laser desorption ionization time-of-flight [MALDI-ToF] mass spectrometry) have fundamentally changed diagnostic procedures. As a consequence, sensitivity and specificity as well as time-to-report have been dramatically improved. In this manuscript, key methodological advances in medical microbiology are discussed, emphasizing consequences for daily management of infectious disease patients.

Influenza and respiratory syncytial virus in infants study (IRIS) of hospitalized and non-ill infants aged <1 year in four countries: study design and methods

Background

This multi-country prospective study of infants aged <1 year aims to assess the frequency of influenza virus and respiratory syncytial virus (RSV) infections associated with hospitalizations, to describe clinical features and antibody response to infection, and to examine predictors of very severe disease requiring intensive care.

Methods/Design

We are enrolling a hospital-based cohort and a sample of non-ill infants in four countries (Albania, Jordan, Nicaragua, and the Philippines) using a common protocol. We are currently starting year 2 of a 2- to 3-year study and will enroll approximately 3,000 infants hospitalized for any acute illness (respiratory or non-respiratory) during periods of local influenza and/or RSV circulation. After informed consent and within 24 h of admission, we collect blood and respiratory specimens and conduct an interview to assess socio-demographic characteristics, medical history, and symptoms of acute illness (onset ≤10 days). Vital signs, interventions, and medications are documented daily through medical record abstraction. A follow-up health assessment and collection of convalescent blood occurs 3-5 weeks after enrollment. Influenza and RSV infection is confirmed by singleplex real time reverse transcriptase polymerase chain reaction (rRT-PCR) assays. Serologic conversion will be assessed comparing acute and convalescent sera using hemagglutination inhibition assay for influenza antibodies and enzyme-linked immunosorbent assay (ELISA) for RSV. Concurrent with hospital-based enrollment, respiratory specimens are also being collected (and tested by rRT-PCR) from approximately 1,400 non-ill infants aged <1 year during routine medical or preventive care.

Discussion

The Influenza and RSV in Infants Study (IRIS) promises to expand our knowledge of the frequency, clinical features, and antibody profiles of serious influenza and RSV disease among infants aged <1 year, quantify the proportion of infections that may be missed by traditional surveillance, and inform decisions about the potential value of existing and new vaccines and other prevention and treatment strategies.

In vitro activity of tedizolid and linezolid against Staphylococcus epidermidis isolated from prosthetic joint infections

Prosthetic joint infections (PJIs) are rare but long-lasting and are serious complications without any spontaneous resolution, requiring additional surgery and long-term treatment with antibiotics. Staphylococci are the most important aetiological agents of PJIs, and among the coagulase-negative staphylococci Staphylococcus epidermidis is the most common. However, S. epidermidis often displays multidrug resistance (MDR), demanding additional treatment options. The objective was to examine the effectiveness of tedizolid and linezolid against S. epidermidis isolated from PJIs. The standard antibiotic susceptibility pattern of S. epidermidis (n = 183) obtained from PJIs was determined by disc diffusion test, and MIC was determined by Etest for tedizolid, linezolid, and vancomycin. Tedizolid displayed MIC values ranging from 0.094 to 0.5 mg/L (MIC₅₀: 0.19 mg/L, MIC₉₀: 0.38 mg/L), linezolid MIC values ranging from 0.25 to 2 mg/L (MIC₅₀: 0.75 mg/L, MIC₉₀: 1 mg/L), and vancomycin MIC values ranging from 0.5 to 3 mg/L (MIC₅₀ and MIC₉₀ both 2 mg/L). According to the disc diffusion test, 153/183 (84%) isolates were resistant to ≥3 antibiotic groups, indicating MDR. In conclusion, S. epidermidis isolates from PJIs were fully susceptible, and the MIC₅₀ and MIC₉₀ values for tedizolid were two- to four-fold dilution steps lower compared with linezolid. Tedizolid is not approved, and there are no reports of long-term treatment, but it may display better tolerability and fewer adverse effects than linezolid; it thus could be a possible treatment option for PJIs, alone or in combination with rifampicin.

Safety of direct antiviral agents for treatment of hepatitis C virus infection

Antiviral drugs for treatment of hepatitis C have grown dramatically in recent years. The emergence of direct antiviral agents (DAAs) is a major advance in hepatitis C treatment. Since the first generation DAAs appeared in 2011, two more generations of DAAs have been approved by the Food and Drug Administration in only five years. With the advantages of coverage of all genotypes, high availability and easy administration, DAAs have been widely used worldwide in recent years. DAAs have nearly solved the main problems encountered in hepatitis C antiviral therapy. However, adverse events associated with DAAs use have been reported constantly, and the safety of DAAs has attracted more and more attention. According to recent reports, the adverse reactions of DAAs have been gradually reduced from the first generation to the third generation. When combined with other drugs, the drug-drug interactions (DDIs) need special attention. In addition, the usage of DAAs in special patient groups should be cautious. In this paper, we will summarize the adverse effects and DDIs of DAAs as well as their usage in the general population and special patient groups.

Psychosocial correlates of nutritional status among people living with HIV on antiretroviral therapy: A matched case-control study in Central zone of Tigray, Northern Ethiopia

BACKGROUND

Malnutrition hastens progression to Acquired Human Immunodeficiency Syndromes (AIDS) related illnesses; undermines adherence and response to antiretroviral therapy (ART) in resource-poor settings. However, nutritional status of people living with HIV (PLHIV) can be affected by various psychosocial factors which have not been well explored in Ethiopia. Therefore, the objective of this study was to determine psychosocial correlates of nutritional status among people living with HIV (PLHIV) on ART in Central zone of Tigray, Northern Ethiopia.

METHODS

A matched case-control study design was conducted to assess psychosocial correlates of nutritional status among PLHIV on ART. Data were collected by an interviewer-administered technique using structured pre-tested questionnaire, record review using a checklist and anthropometric measurements. Cases were selected by simple random sampling and controls purposively to match the selected cases. Conditional logistic regression was used to compute relevant associations by STATA version 12.

RESULTS

The psychosocial factors independently associated with malnutrition were ever consuming alcohol after starting ART [AOR = 4.7, 95% CI: 1.8-12.3], ever smoking cigarette after starting ART [AOR = 7.6, 95% CI: 2.3-25.5], depression [AOR = 2.8, 95% CI: 1.3, 6.1], not adhering to ART [AOR = 6.8,95% CI: 2.0-23.0] and being in the second lowest wealth quintile [AOR = 4.3,95% CI: 1.1-17.7].

CONCLUSION

Ever consuming alcohol and ever smoking cigarette after starting ART, depression, not adhering to ART and being in the second lowest wealth quintile were significantly associated with malnutrition. Therefore; policies, strategies, and programs targeting people living with HIV should consider psychosocial factors that can impact nutritional status of people living with HIV enrolled on ART.

Dosing strategies to optimize currently available anti-MRSA treatment options (Part 1: IV options)

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a predominant pathogen resulting in significant morbidity and mortality. Optimal dosing of anti-MRSA agents is needed to help prevent the development of antimicrobial resistance and to increase the likelihood of a favorable clinical outcome. Areas covered: This review summarizes the available data for antimicrobials routinely used for MRSA infections that are not administered orally or topically. We make recommendations and highlight the current gaps in the literature. A PubMed (1966 - Present) search was performed to identify relevant literature for this review. Expert commentary: Improvements in MIC determination and therapeutic drug monitoring are needed to fully implement individualized dosing that optimizes antimicrobial pharmacodynamics.Additional data will become available for these agents in regards to effectiveness for severe MRSA infections and pharmacokinetic data for special patient populations.

Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options

Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized.

Childhood pneumococcal disease in Africa - A systematic review and meta-analysis of incidence, serotype distribution, and antimicrobial susceptibility

BACKGROUND

Determining the incidence, disease-associated serotypes and antimicrobial susceptibility of invasive pneumococcal disease (IPD) among children in Africa is essential in order to monitor the impact of these infections prior to widespread introduction of the pneumococcal conjugate vaccine (PCV).

METHODS

To provide updated estimates of the incidence, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae causing disease in Africa, we performed a systematic review of articles published from 2000 to 2015 using Ovid Medline and Embase. We included prospective and surveillance studies that applied predefined diagnostic criteria. Meta-analysis for all pooled analyses was based on random-effects models.

RESULTS

We included 38 studies consisting of 386,880 participants in 21 countries over a total of 350,613 person-years. The pooled incidence of IPD was 62.6 (95% CI 16.9, 226.5) per 100,000 person-years, including meningitis which had a pooled incidence of 24.7 (95% CI 11.9, 51.6) per 100,000 person-years. The pooled prevalence of penicillin susceptibility was 78.1% (95% CI 61.9, 89.2). Cumulatively, PCV10 and PCV13 included 66.9% (95% CI 55.9, 76.7) and 80.6% (95% CI 66.3, 90.5) of IPD serotypes, respectively.

CONCLUSIONS

Our study provides an integrated and robust summary of incidence data, serotype distribution and antimicrobial susceptibility for S. pneumoniae in children ≤5years of age in Africa prior to widespread introduction of PCV on the continent. The heterogeneity of studies and wide range of incidence rates across the continent indicate that surveillance efforts should be intensified in all regions of Africa to improve the integrity of epidemiologic data, vaccine impact and cost benefit. Although the incidence of IPD in young children in Africa is substantial, currently available conjugate vaccines are estimated to cover the majority of invasive disease-causing pneumococcal serotypes. These data provide a reliable baseline from which to monitor the impact of the broad introduction of PCV.

Within-host whole genome analysis of an antibiotic resistant Pseudomonas aeruginosa strain sub-type in cystic fibrosis

A Pseudomonas aeruginosa AUST-02 strain sub-type (M3L7) has been identified in Australia, infects the lungs of some people with cystic fibrosis and is associated with antibiotic resistance. Multiple clonal lineages may emerge during treatment with mutations in chromosomally encoded antibiotic resistance genes commonly observed. Here we describe the within-host diversity and antibiotic resistance of M3L7 during and after antibiotic treatment of an acute pulmonary exacerbation using whole genome sequencing and show both variation and shared mutations in important genes. Eleven isolates from an M3L7 population (n = 134) isolated over 3 months from an individual with cystic fibrosis underwent whole genome sequencing. A phylogeny based on core genome SNPs identified three distinct phylogenetic groups comprising two groups with higher rates of mutation (hypermutators) and one non-hypermutator group. Genomes were screened for acquired antibiotic resistance genes with the result suggesting that M3L7 resistance is principally driven by chromosomal mutations as no acquired mechanisms were detected. Small genetic variations, shared by all 11 isolates, were found in 49 genes associated with antibiotic resistance including frame-shift mutations (mexA, mexT), premature stop codons (oprD, mexB) and mutations in quinolone-resistance determining regions (gyrA, parE). However, whole genome sequencing also revealed mutations in 21 genes that were acquired following divergence of groups, which may also impact the activity of antibiotics and multi-drug efflux pumps. Comparison of mutations with minimum inhibitory concentrations of anti-pseudomonal antibiotics could not easily explain all resistance profiles observed. These data further demonstrate the complexity of chronic and antibiotic resistant P. aeruginosa infection where a multitude of co-existing genotypically diverse sub-lineages might co-exist during and after intravenous antibiotic treatment.

First versus second year respiratory syncytial virus prophylaxis in chronic lung disease (2005-2015)

Children aged <2 years with chronic lung disease (CLD) have a 10-fold higher risk for respiratory syncytial virus-positive hospitalization (RSVH) compared to healthy term infants. Based on the updated position statements, we compared respiratory-related illness hospitalization (RIH) and RSVH risks in CLD children who received palivizumab during the first year (FY) versus second year (SY) of life in the Canadian Registry of Palivizumab (CARESS). Demographic data were collected at enrolment and RIH events recorded monthly from 2005 to 2015. Eight hundred forty-seven FY and 450 SY children with CLD were identified. SY children had a lower gestational age (27 versus 29 weeks) and required more days of respiratory support (64 versus 43), oxygen therapy (108 versus 55), and length of stay (118 versus 73) during the neonatal course compared to FY children; all p < 0.0005. RIH rates were 12.2 (FY) and 18.2 (SY), and RSVH rates were 2.3 (FY) and 3.9 (SY). Cox regression showed similar hazards for both RIH (hazard ratio 0.9, 95% CI 0.6-1.6, p = 0.812) and RSVH (hazard ratio 1.1, 95% CI 0.4-2.9, p = 0.920).

CONCLUSIONS

SY and FY children had similar risks for RIH and RSVH. The findings imply that SY children with CLD are correctly selected for palivizumab based on neonatal illness severity and merit prophylaxis. What is Known: • Children with chronic lung disease have a 10-fold higher risk for RSV-positive hospitalization in comparison to healthy term infants and commonly receive palivizumab prophylaxis as a preventative measure against serious RSV-related lower respiratory tract infections. • The American Academy of Pediatrics [ 2 ] and the Canadian Paediatric Society [ 30 ] have recently modified their recommendations for RSV prophylaxis in children with chronic lung disease, limiting palivizumab to either those <32 weeks gestation or those in the first year of life who are oxygen dependent or require medical therapy for the treatment of their condition. What is New: • Children with chronic lung disease receiving an additional course of palivizumab in their second year of life were determined to be at similar risk for both respiratory illness-related hospitalization and RSV-positive hospitalization as palivizumab-naïve children enrolled in the first year of life in the Canadian Registry for palivizumab (CARESS). • CARESS physicians are correctly identifying high-risk children with chronic lung disease in their second year of life, whom they believe will benefit from an additional year of palivizumab prophylaxis, based on neonatal illness severity.

Association Between Food Insecurity and HIV Viral Suppression: A Systematic Review and Meta-Analysis

Although an increasing number of HIV infected people are accessing antiretroviral treatment, many do not achieve complete HIV viral suppression and remain at risk for AIDS and capable of HIV transmission. Food insecurity has been identified as a potential risk factor for poor virologic response, but the association between these factors has been inconsistently documented in the literature. We systematically searched five electronic databases and bibliographies of relevant studies through April 2015 and retrieved 11 studies that met our inclusion criteria, of which nine studies were conducted in North America and the remaining two studies were in Brazil and Uganda respectively. Meta-analyzed results indicated that experiencing food insecurity resulted in 29% lower odds of achieving complete HIV viral suppression (OR = 0.71, 95% CI 0.61-0.82) and this significant inverse association was consistently found regardless of study design, exposure measurement, and confounder adjustment methods. These findings suggest that food insecurity is a potential risk factor for incomplete HIV viral suppression in people living with HIV.

Single-Dose Oritavancin Compared to Standard of Care IV Antibiotics for Acute Bacterial Skin and Skin Structure Infection in the Outpatient Setting: A Retrospective Real-World Study

INTRODUCTION

Cost-containment strategies are shifting the treatment of acute bacterial skin and skin structure infections (ABSSSI) from inpatient to outpatient settings. Current standard of care (SoC) requires multiple-dose regimens, which are associated with high hospitalization rates and high costs. Oritavancin, a new single-dose antibiotic for ABSSSI, may be suitable for outpatient therapy. This analysis evaluates the effectiveness, costs, and resource utilization of oritavancin vs. SoC in a real-world, outpatient setting.

METHODS

A single-site, retrospective chart review was conducted of 118 adult patients diagnosed with ABSSSI and treated with either single-dose oritavancin or multi-dose SoC therapy between 6 August 2014 and 30 June 2015. Patients were assigned to two matched cohorts: oritavancin and SoC. Primary clinical effectiveness endpoints was the success (cured or improved) at 5-30 days after the course of antibiotic therapy has been completed. Secondary economic endpoints were total costs and healthcare resource utilization.

RESULTS

Oritavancin showed comparable clinical effectiveness vs. multi-dose SoC in the outpatient setting. A similar percentage of patients in the oritavancin (90.2%) and SoC cohorts (77.4%) achieved successful outcomes ("cure" or "improved"), with the cure rate higher for oritavancin (73.2%) vs. SoC (48.4%; P = 0.0315). Oritavancin's clinical effectiveness was consistent across patient subgroups with varying demographic, clinical, and ABSSSI characteristics. Oritavancin was consistently associated with lower costs (per-patient savings $2319) and reduced resource utilization measures, and it required just 1.0 day of therapy vs. 7.2 days for SoC.

CONCLUSION

Oritavancin is well suited for the outpatient treatment of ABSSSI. Compared with SoC, oritavancin offers comparable effectiveness, is more economical, and requires fewer healthcare resources.

Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study

BACKGROUND

There are few real-life data on the potential drug-drug interactions (DDIs) between anti-HCV direct-acting antivirals (DAAs) and the comedications used.

AIM

To assess the potential DDIs of DAAs in HCV-infected outpatients, according to the severity of liver disease and comedication used in a prospective multicentric study.

METHODS

Data from patients in 15 clinical centers who had started a DAA regimen and were receiving comedications during March 2015 to March 2016 were prospectively evaluated. The DDIs for each regimen and comedication were assigned according to HepC Drug Interactions (www.hep-druginteractions.org).

RESULTS

Of the 449 patients evaluated, 86 had mild liver disease and 363 had moderate-to-severe disease. The use of a single comedication was more frequent among patients with mild liver disease (p = 0.03), whereas utilization of more than three drugs among those with moderate-to-severe disease (p = 0.05). Of the 142 comedications used in 86 patients with mild disease, 27 (20%) may require dose adjustment/closer monitoring, none was contraindicated. Of the 322 comedications used in 363 patients with moderate-to-severe liver disease, 82 (25%) were classified with potential DDIs that required only monitoring and dose adjustments; 10 (3%) were contraindicated in severe liver disease. In patients with mild liver disease 30% (26/86) used at least one drug with a potential DDI whereas of the 363 patients with moderate-to-severe liver disease, 161 (44%) were at risk for one or more DDI.

CONCLUSIONS

Based on these results, we can estimate that 30-44% of patients undergoing DAA and taking comedications are at risk of a clinically significant DDI. This data indicates the need for increased awareness of potential DDI during DAA therapy, especially in patients with moderate-to-severe liver disease. For several drugs, the recommendation related to the DDI changes from "dose adjustment/closer monitoring", in mild to moderate liver disease, to "the use is contraindicated" in severe liver disease.

Risk stacking of pneumococcal vaccination indications increases mortality in unvaccinated adults with Streptococcus pneumoniae infections

BACKGROUND

Several chronic disease states have been identified as pneumococcal vaccination indications due to their ability to increase pneumococcal disease development and subsequent mortality. However, the risk of mortality according to the number of these disease states present is unknown. We sought to determine the impact of concomitant, multiple risk factors (stacked risks) for pneumococcal disease on 30-day mortality in adults.

METHODS

This was a national case-control study of unvaccinated older Veterans (≥50years of age) admitted to Veterans Affairs medical centers from 2002 to 2011 with serious pneumococcal infections (pneumonia, bacteremia, meningitis) based on positive S. pneumoniae blood, cerebrospinal fluid, or respiratory cultures, respectively. Cases were those not alive 30days following culture, while controls were alive. Using logistic regression, we quantified risk of 30-day mortality among patients with stacked risk factors, including age ≥65years, alcohol abuse, chronic heart disease, chronic liver disease, chronic respiratory disease, diabetes mellitus, immunodeficiency, and smoking.

RESULTS

We identified 9730 serious pneumococcal infections, with an overall 30-day mortality rate of 18.6% (1764 cases, 7966 controls). Infection types included pneumonia (62%), bacteremia (26%), and bacteremic pneumonia (11%). Along with eight individual risk factors, we assessed 247 combinations of risk factors. Most cases (85%) and controls (74%) had at least two risk factors. Mortality increased as risks were stacked, up to six risk factors (one: OR 1.5, CI 1.08-2.07; two: OR 2.01, CI 1.47-2.75; three: OR 2.71, CI 1.99-3.69; four: OR 3.27, CI 2.39-4.47; five: OR 3.63, CI 2.60-5.07; six: OR 4.23, CI 2.69-6.65), with each additional risk factor increasing mortality an average of 55% (±13%).

CONCLUSIONS

Among adults ≥50years with serious pneumococcal disease, mortality risk increased approximately 55% as vaccination indications present increased. Mortality with six stacked indications was double that of two indications.

Ledipasvir plus sofosbuvir as salvage therapy for HCV genotype 1 failures to prior NS5A inhibitors regimens

There is little information on retreatment efficacy and predictors of the combination of ledipasvir and sofosbuvir (ledipasvir/sofosbuvir) for patients who fail to respond to NS5A inhibitors. NS5A resistance variants are known to persist for long periods after such treatment. Here, we evaluated 54 patients with chronic HCV genotype 1b infection, free of decompensated cirrhosis, and hepatocellular carcinoma, for sustained virological response after 12 weeks (SVR12) of once-daily treatment with 90 mg ledipasvir and 400 mg sofosbuvir. Intention-to-treat analysis showed SVR12 of 70%. Using ultra-deep sequencing, non-responder to ledipasvir/sofosbuvir showed no change in the rates of detection of NS5A and NS5B resistant-variants at re-elevation of viral loads, relative to baseline. According to response to prior treatment, SVR12 rates were 18, 69, 94, and 100% in non response, viral breakthrough, relapse, and discontinuation due to adverse events, respectively. SVR12 rates in non response were significantly lower than those of the others. Multivariate analysis identified response to previous treatment (failure except for non response) and FIB4 index (<3.25) as significant determinants of SVR12. The SVR12 rates were significantly lower in patients with FIB4 index of ≥3.25 and had not responded to prior treatment, relative to others. The specificity, and positive- and negative-predictive values were high for prediction of poor response based on the combination of two predictors. In conclusion, our study indicated that ledipasvir/sofosbuvir is a potentially useful salvage treatment for patients who fail prior NS5A inhibitors-based therapy. Response to prior treatment was an important predictor of retreatment efficacy.

Characterization of pathogenesis of and immune response to Burkholderia pseudomallei K96243 using both inhalational and intraperitoneal infection models in BALB/c and C57BL/6 mice

Burkholderia pseudomallei, the etiologic agent of melioidosis, is a Gram negative bacterium designated as a Tier 1 threat. This bacterium is known to be endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. Inhalational melioidosis has been associated with monsoonal rains in endemic areas and is also a significant concern in the biodefense community. There are currently no effective vaccines for B. pseudomallei and antibiotic treatment can be hampered by non-specific symptomology and also the high rate of naturally occurring antibiotic resistant strains. Well-characterized animal models will be essential when selecting novel medical countermeasures for evaluation prior to human clinical trials. Here, we further characterize differences between the responses of BALB/c and C57BL/6 mice when challenged with low doses of a low-passage and well-defined stock of B. pseudomallei K96243 via either intraperitoneal or aerosol routes of exposure. Before challenge, mice were implanted with a transponder to collect body temperature readings, and daily body weights were also recorded. Mice were euthanized on select days for pathological analyses and determination of the bacterial burden in selected tissues (blood, lungs, liver, and spleen). Additionally, spleen homogenate and sera samples were analyzed to better characterize the host immune response after infection with aerosolized bacteria. These clinical, pathological, and immunological data highlighted and confirmed important similarities and differences between these murine models and exposure routes.

Neuronal Stress and Injury Caused by HIV-1, cART and Drug Abuse: Converging Contributions to HAND

Multiple mechanisms appear to contribute to neuronal stress and injury underlying HIV-associated neurocognitive disorders (HAND), which occur despite the successful introduction of combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can itself be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine (METH), seems to compromise antiretroviral therapy and aggravate HAND. However, the combined effect of virus and recreational and therapeutic drugs on the brain is still incompletely understood. However, several lines of evidence suggest a shared critical role of oxidative stress, compromised neuronal energy homeostasis and autophagy in promotion and prevention of neuronal dysfunction associated with HIV-1 infection, cART and psychostimulant use. In this review, we present a synopsis of recent work related to neuronal stress and injury induced by HIV infection, antiretrovirals (ARVs) and the highly addictive psychostimulant METH.

Interferon β-1a for the treatment of Ebola virus disease: A historically controlled, single-arm proof-of-concept trial

To date there are no approved antiviral drugs for the treatment of Ebola virus disease (EVD). Based on our in vitro evidence of antiviral activity of interferon (IFN)-ß activity against Ebola virus, we conducted a single arm clinical study in Guinea to evaluate the safety and therapeutic efficacy of IFN β-1a treatment for EVD. Nine individuals infected with Ebola virus were treated with IFN β-1a and compared retrospectively with a matched cohort of 21 infected patients receiving standardized supportive care only during the same time period at the same treatment unit. Cognizant of the limitations of having treated only 9 individuals with EVD, the data collected are cautiously considered. When compared to supportive care only, IFN β-1a treatment seemed to facilitate viral clearance from the blood and appeared associated with earlier resolution of disease symptoms. Survival, calculated from the date of consent for those in the trial and date of admission from those in the control cohort, to the date of death, was 19% for those receiving supportive care only, compared to 67% for those receiving supportive care plus IFN β-1a. Given the differences in baseline blood viremia between the control cohort and the IFN-treated cohort, an additional 17 controls were included for a subset analysis, from other treatment units in Guinea, matched with the IFN-treated patients based on age and baseline blood viremia. Subset analyses using this expanded control cohort suggests that patients without IFN β-1a treatment were ~ 1.5–1.9 fold more likely to die than those treated. Viewed altogether the results suggest a rationale for further clinical evaluation of IFN β-1a.

Infections in inflammatory bowel disease

Patients with inflammatory bowel disease constitute a population with a special predisposition to develop bacterial, viral and fungal infections. Iatrogenic immunosuppression, frequent contact with healthcare facilities and surgical interventions are some of the risk factors that explain why these infections are one of the main causes of morbi-mortality in this disease. Some of these infections follow a subtle and paucisymptomatic evolution; their diagnosis and management may become a real challenge for the attending physician if their screening is not systematized or they are not considered in the differential diagnosis. The objective of this review is to provide an update from a practical and concise perspective on the knowledge regarding the epidemiology, prevention, diagnosis and treatment of the most common infections.

Suramin interacts with the positively charged region surrounding the 5-fold axis of the EV-A71 capsid and inhibits multiple enterovirus A

Suramin was previously shown to bind to the EV-A71 capsid through its naphthalenetrisulfonic acid groups, thereby reducing virus-cell binding and inhibiting viral replication. Here, we identify VP1-145 as the critical amino acid that accounts for the differential sensitivity of EVA-71 viruses to suramin. A single Q or G to E substitution at VP1-145 results in an approximately 30-fold shift of IC₅₀ or IC₉₀ values reproducing the inhibition profile observed with field isolates expressing either the 145Q or E mutation. Our data support the conclusion that suramin binds to the positively charged region surrounding the 5-fold axis of the capsid and consequently blocks the virus attachment and entry into host cells. In order to assess the antiviral-spectrum of suramin, we analyzed 18 representative enteroviruses: A (n = 7), B (n = 5), C (n = 5) and D (n = 1). We show that suramin potency is restricted to enterovirus A species. Clinical development of suramin is further supported by pharmacokinetic data demonstrating bioactive plasma levels after a single dose intramuscular administration in macaques. Altogether, our findings support the clinical development of suramin as a novel entry inhibitor for the treatment of enterovirus A infections.

Toxic Megacolon - A Three Case Presentation

Introduction

Toxic megacolon is a life-threatening disease and is one of the most serious complications of Clostridium difficile infection (CDI), usually needing prompt surgical intervention. Early diagnosis and adequate medical treatment are mandatory.

Cases presentation

In the last two years, three Caucasian female patients have been diagnosed with toxic megacolon and treated in the Clinical Infectious Diseases Hospital, Constanta. All patients had been hospitalized for nonrelated conditions. The first patient was in chemotherapy for non-Hodgkin’s lymphoma, the second patient had undergone surgery for colon cancer, and the third patient had surgery for disc herniation. In all cases the toxin test (A+B) was positive and ribotype 027 was present. Abdominal CT examination, both native and after intravenous contrast, showed significant colon dilation, with marked thickening of the wall. Resolution of the condition did not occur using the standard treatment of metronidazole and oral vancomycin, therefore the therapy was altered in two cases using intracolonic administration of vancomycin and intravenous tigecycline.

Conclusions

In these three cases of CDI, the risk factors for severe evolution were: concurrent malignancy, renal failure, obesity, and immune deficiencies. Ribotype 027, a marker for a virulent strain of CD, was found in all three cases complicated by toxic megacolon. The intracolonic administration of vancomycin, and intravenous tigecycline was successful when prior standard therapy had failed, and surgery was avoided.

Effectiveness and safety of daptomycin in patients with infective endocarditis undergoing heart valve replacement: a subgroup analysis from real-world data

BACKGROUND

European Cubicin^® Outcomes Registry and Experience (EU-CORE) was a retrospective, non-interventional, multicenter registry that collected real-world clinical outcomes following daptomycin use for the treatment of Gram-positive infections. EU-CORE data from patients with infective endocarditis (IE) who underwent heart valve replacement were analysed.

METHODS

Clinical outcomes were assessed as success (cured or improved), failure, or non-evaluable. Adverse events (AEs) were recorded for up to 30 days after daptomycin treatment.

RESULTS

Of 610 patients with IE, 198 [32.5%; left-sided IE (LIE), 166 (83.8%); right-sided IE (RIE), 21 (10.6%); both LIE and RIE, 11 (5.6%)] underwent heart valve replacement. Other than cardiovascular disease, renal disease (18.2%), sepsis (16.2%), and diabetes mellitus (15.2%) were the most significant underlying diseases. Major pathogens in patients with positive culture results (68.0%) were Staphylococcus aureus [36.8%; methicillin-resistant S. aureus (MRSA), 12.8%] and coagulase-negative staphylococci (CoNS; 31.6%). Daptomycin treatment [median duration (range), 21 days (1-112)] resulted in high clinical success in patients with S. aureus (88.4%; MRSA, 80.0%) and CoNS (81.1%) infections, with an overall success rate of 83.3%. Clinical success rate was high (90.0%) in patients who received daptomycin dose >6 mg/kg/day. Overall clinical success rate in patients followed for up to 2 years was 90.7%. AEs and serious AEs possibly related to daptomycin were reported in 6 (3.0%) and 4 (2.0%) patients, respectively.

CONCLUSIONS

Daptomycin treatment was effective and well tolerated with a sustained response in patients with IE who underwent heart valve surgery. A trend towards better clinical outcomes was observed with higher daptomycin doses.

Molecular characterisation of antimicrobial resistance in Pseudomonas aeruginosa and Acinetobacter baumannii during 2014 and 2015 collected across India

BACKGROUND

Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India - Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta-lactamases (ESBLs) and carbapenemases among multidrug-resistant (MDR) P. aeruginosa and A. baumannii.

MATERIALS AND METHODS

A multi-centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra-abdominal infections. Kirby-Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases.

RESULTS

Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA-23like (98%), blaOXA-58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA-51like gene, intrinsic to A. baumannii was present in all the isolates tested.

CONCLUSION

The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid-mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.

Pharmacokinetic drug evaluation of tedizolid for the treatment of skin infections

INTRODUCTION

Tedizolid is indicated for the treatment of acute bacterial skin and skin structure infections (ABSSSI). Although tedizolid shares many similar properties with linezolid, another oxazolidinone used to treat ABSSSI, the two antibiotics have several key differences. Areas covered: This review provides a detailed summary of the overall pharmacodynamics, pharmacokinetics, clinical efficacy, and safety of tedizolid for the treatment of ABSSSI. Expert opinion: Compared to other antibiotics used for ABSSSI, tedizolid has several advantages. Tedizolid has a long half-life, allowing for once daily dosing. Tedizolid also has broad spectrum of activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, Coagulase-negative Staphylococci, and Enterococci - including isolates demonstrating resistance to linezolid. It is available in both oral and intravenous formulations, and, has outstanding oral bioavailability, allowing for oral-step down therapy. There is also some evidence that, tedizolid has fewer significant interactions with serotonin reuptake inhibitors or monoamine oxidase inhibitors than linezolid. Finally, thrombocytopenia may occur less often with tedizolid than linezolid. However, these benefits must be weighed against the financial cost of tedizolid and the availability of alternative antibiotic choices.

Ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia

PURPOSE

The utility of ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is reviewed.

SUMMARY

Ceftaroline was originally approved for the treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSIs) but recently received an additional approval for the treatment of S. aureus bacteremia (SAB) associated with ABSSSIs. Ceftaroline has demonstrated efficacy for the treatment of MRSAB, including isolates with elevated minimum inhibitory concentrations to conventional therapy when used alone or in combination with other agents. In multiple studies, ceftaroline has displayed rapid bloodstream eradication, even in the setting of refractory MRSAB or infective endocarditis. The clinical resolution of MRSAB or SAB in patients who received ceftaroline ranged from 31.0% to 83.3%; studies used varying definitions for clinical resolution and included differing proportions of patients with endocarditis. The use of ceftaroline in treatment-refractory patients and assorted populations makes absolute effectiveness difficult to determine. Ceftaroline has been shown to be effective in patients who have not responded to other agents for MRSAB, making it an attractive option for such patients. Although the approved dosing regimen for ceftaroline fosamil is 600 mg every 12 hours for patients with normal renal function for the treatment of ABSSSIs and CABP, there is some debate about whether more frequent doses (i.e., every 8 hours) are needed for MRSAB.

CONCLUSION

Ceftaroline has been used to successfully treat SAB, including endocarditis. Therapy with ceftaroline may be considered when antibiotic resistance or previous treatment failure precludes the use of first-line agents.

Does Adjunctive Tigecycline Improve Outcomes in Severe-Complicated, Nonoperative Clostridium difficile Infection?

Severe Clostridium difficile infection is associated with a high rate of mortality; however, the optimal treatment for severe- complicated infection remains uncertain for patients who are not candidates for surgical intervention. Thus, we sought to evaluate the benefit of adjunctive tigecycline in this patient population using a retrospective cohort adjusted for propensity to receive tigecycline. We found that patients who received tigecycline had similar outcomes to those who did not, although the small sample size limited power to adjust for comorbidities and severity of illness.