Transmission patterns of HIV-1 non-R5 strains in Poland.

HIV-1 env sequencing enables predictions of viral coreceptor tropism and phylogenetic investigations of transmission events. The aim of the study was to estimate the contribution of non-R5 strains to the viral spread in Poland. Partial proviral env sequences were retrieved from baseline blood samples of patients with newly diagnosed HIV-1 infection between 2008-2014, including 46 patients with recent HIV-1 infection (RHI), and 246 individuals with long-term infection (LTHI). These sequences were subjected to the genotypic coreceptor tropism predictions and phylogenetic analyses to identify transmission clusters. Overall, 27 clusters with 57 sequences (19.5%) were detected, including 15 sequences (26.3%) from patients with RHI. The proportion of non-R5 strains among all study participants was 23.3% (68/292), and was comparable between patients with RHI and LTHI (11/46, 23.9% vs 57/246, 23.2%; p = 1.000). All 11 patients with non-R5 strains and RHI were men having sex with men (MSM). Among these patients, 4 had viral sequences grouped within phylogenetic cluster with another sequence of non-R5 strain obtained from patient with LTHI, indicating potential acquisition of non-R5 HIV-1 for at least 4/46 (8.7%) patients with RHI. We were unable to confirm the contribution of patients with RHI to the forward transmission of non-R5 strains, but a relatively high proportion of non-R5 strains among them deserves attention due to the limited susceptibility to CCR5 antagonists.

Antimicrobial Potential of Caffeic Acid against Staphylococcus aureus Clinical Strains.

Phenolic compounds constitute one of the most promising and ubiquitous groups with many biological activities. Synergistic interactions between natural phenolic compounds and antibiotics could offer a desired alternative approach to the therapies against multidrug-resistant bacteria. The objective of the presented study was to assess the antibacterial potential of caffeic acid (CA) alone and in antibiotic-phytochemical combination against Staphylococcus aureus reference and clinical strains isolated from infected wounds. The caffeic acid tested in the presented study showed diverse effects on S. aureus strains with the minimum inhibitory concentration (MIC) varied from 256 µg/mL to 1024 µg/mL. The supplementation of Mueller-Hinton agar (MHA) with 1/4 MIC of CA resulted in augmented antibacterial effect of erythromycin, clindamycin, and cefoxitin and to the lesser extent of vancomycin. The observed antimicrobial action of CA seemed to be rather strain than antibiotic dependent. Our data support the notion that CA alone exerts antibacterial activity against S. aureus clinical strains and has capacity to potentiate antimicrobial effect in combination with antibiotics. The synergy between CA and antibiotics demonstrates its potential as a novel antibacterial tool which could improve the treatment of intractable infections caused by multidrug-resistant strains.

Regulatory region single nucleotide polymorphisms of the apolipoprotein E gene as risk factors for Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by a complex aetiology. The ε4 allel of the apolipoprotein E gene (APOE) is the only confirmed genetic risk factor for the development of AD. In addition, polymorphisms at the promoter region of the APOE gene are assumed to modulate the susceptibility to AD by their different affinity to the transcription factors thus affecting the expression of the gene. In the presented study, we investigated the association between -491 A/T (rs449647), -427C/T, (rs769446) and -219 T/G (rs405509) single nucleotide polymorphisms (SNPs) of APOE gene and AD risk in the Polish population. We found that only the -491 T allele and -491 A/T genotype acted as protective factors against AD, whereas the -219 T/G heterozygosity increased risk for AD in APOE ε4 carriers but not in APOE ε4 non-carriers. What is more, haplotype frequency estimation showed significant positive for A-T-T-C-C and A-T-G-C-C haplotypes or negative for A-T-T-T-C and T-T-T-T-C haplotypes associations with AD. These results contribute to the evidence that APOE promoter polymorphisms modulate risk for AD.

Vancomycin and/or Multidrug-Resistant Citrobacter Freundii Altered the Metabolic Pattern of Soil Microbial Community.

Despite many studies, our knowledge on the impact of antibiotics and antibiotic-resistant bacteria on the metabolic activity of soil microbial communities is still limited. To ascertain this impact, the community level physiological profiles (CLPPs) and the activity of selected enzymes (dehydrogenase, urease, and phosphatases) in soils treated with vancomycin (VA) and/or multidrug resistant Citrobacter freundii were determined during a 90-day experiment. A multivariate analysis and the resistance (RS)/resilience (RL) concept were used to assess the potential of native microorganisms to maintain their catabolic activity under exposure of VA and/or a high level of C. freundii. In addition, the dissipation rate of VA was evaluated in non-sterile (nsS) and sterile (sS) soils. The results revealed a negative impact of VA on the metabolic activity of soil microorganisms on days 1, 15, and 30 as was showed by a decrease in the values of the CLPP indices (10-69%) and the enzyme activities (6-32%) for treated soils as compared to the control. These observations suggested a low initial resistance of soil microorganisms to VA and/or C. freundii but they were resilient in the long term. Considering the mean values of the RS index, the resistance of measured parameters was categorized in the following order: alkaline phosphatase (0.919) > acid phosphatase (0.899) > dehydrogenase (0.853) > the evenness index (0.840) > urease (0.833) > the Shannon-Wiener index (0.735) > substrate richness (0.485) > the AWCD (0.301). The dissipation process of VA was relatively fast and independent of the concentration used. The DT50 values for VA applied at both concentrations were about 16 days. In addition, the dissipation of VA in nsS was three times faster compared to the dissipation of antibiotic in sS. In conclusion, both CLPP and enzyme activities assays appeared to be useful tool for the determination of disturbances within soil microbial communities and used together may be helpful to understand the changes in their catabolic features. The entry of large quantities of VA and/or C. freundii into soil may temporarily change microbial activity thus pose a potential risk for soil functioning.

HIV-1 Infection in Persons Homozygous for CCR5-Δ32 Allele: The Next Case and the Review.

CC-chemokine receptor 5 serves as the coreceptor for the HIV-1 R5 strains, which are responsible for the majority of HIV transmissions. A deletion of 32 nucleotides in the gene encoding this receptor (termed CCR5-Δ32) leads to the suppression of CC-chemokine receptor 5 presentation at the cell surface, thus impeding process of HIV entry into the cell. Individuals homozygous for the CCR5-Δ32 allele are resistant to infection with HIV-1 R5 strains, and are extremely rare among HIV-1-infected individuals. We have described a case of person homozygous for CCR5-Δ32, who was infected with subtype B HIV-1. Based on examination of proviral V3 sequences obtained from the first clinical blood sample within less than five months after seroconversion, the CXC-chemokine receptor 4-using strains (X4 or R5/X4) were detected. Data on HIV-1-infected patients homozygous for the CCR5-Δ32 allele, course of HIV-1 infection in these cases, and the infecting viral strains from current and all former reports on HIV-1 infection in CCR5-Δ32 homozygotes were gathered and compared. Identification of HIV-1-infected persons homozygous for CCR5-Δ32 supports the evidence that the lack of functional CC-chemokine receptor 5 at the cell surface does not confer absolute protection against HIV-1 infection, which should be considered when designing future HIV pre-exposure prophylaxis schemes basing on CC-chemokine receptor 5 blocking drugs.

Prevalence of Transmitted Drug-Resistance Mutations and Polymorphisms in HIV-1 Reverse Transcriptase, Protease, and gp41 Sequences Among Recent Seroconverters in Southern Poland.

BACKGROUND Monitoring of drug resistance-related mutations among patients with recent HIV-1 infection offers an opportunity to describe current patterns of transmitted drug resistance (TDR) mutations. MATERIAL AND METHODS Of 298 individuals newly diagnosed from March 2008 to February 2014 in southern Poland, 47 were deemed to have recent HIV-1 infection by the limiting antigen avidity immunoassay. Proviral DNA was amplified and sequenced in the reverse transcriptase, protease, and gp41 coding regions. Mutations were interpreted according to the Stanford Database algorithm and/or the International Antiviral Society USA guidelines. TDR mutations were defined according to the WHO surveillance list. RESULTS Among 47 patients with recent HIV-1 infection only 1 (2%) had evidence of TDR mutation. No major resistance mutations were found, but the frequency of strains with ≥1 accessory resistance-associated mutations was high, at 98%. Accessory mutations were present in 11% of reverse transcriptase, 96% of protease, and 27% of gp41 sequences. Mean number of accessory resistance mutations in the reverse transcriptase and protease sequences was higher in viruses with no compensatory mutations in the gp41 HR2 domain than in strains with such mutations (p=0.031). CONCLUSIONS Despite the low prevalence of strains with TDR mutations, the frequency of accessory mutations was considerable, which may reflect the history of drug pressure among transmitters or natural viral genetic diversity, and may be relevant for future clinical outcomes. The accumulation of the accessory resistance mutations within the pol gene may restrict the occurrence of compensatory mutations related to enfuvirtide resistance or vice versa.

Susceptibility of Staphylococcus aureus clinical isolates to propolis extract alone or in combination with antimicrobial drugs.

The objective of this study was to assess in vitro the antimicrobial activity of ethanolic extract of Polish propolis (EEPP) against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. The combined effect of EEPP and 10 selected antistaphylococcal drugs on S. aureus clinical cultures was also investigated. EEPP composition was analyzed by a High Performance Liquid Chromatography (HPLC) method. The flavonoid compounds identified in Polish Propolis included flavones, flavonones, flavonolols, flavonols and phenolic acids. EEPP displayed varying effectiveness against twelve S. aureus strains, with minimal inhibitory concentration (MIC) within the range from 0.39 to 0.78 mg/mL, determined by broth microdilution method. The average MIC was 0.54 ± 0.22 mg/mL, while calculated MIC50 and MIC90 were 0.39 mg/mL and 0.78 mg/mL, respectively. The minimum bactericidal concentration (MBC) of the EEPP ranged from 0.78 to 3.13 mg/mL. The in vitro combined effect of EEPP and 10 antibacterial drugs was investigated using disk diffusion method-based assay. Addition of EEPP to cefoxitin (FOX), clindamycin (DA), tetracycline (TE), tobramycin (TOB), linezolid (LIN), trimethoprim+sulfamethoxazole (SXT), penicillin (P), erythromycin (E) regimen, yielded stronger, cumulative antimicrobial effect, against all tested S. aureus strains than EEPP and chemotherapeutics alone. In the case of ciprofloxacin (CIP) and chloramphenicol (C) no synergism with EEPP was observed.

Transmission of drug-resistant HIV-1 variants among individuals with recent infection in southern Poland.

Transmitted drug resistance (TDR) is an important public health issue, because it may affect the outcome of antiretroviral treatment. The prevalence of human immunodeficiency virus type 1 (HIV-1) with TDR mutations defined according to the list of the World Health Organization was investigated among 53 therapy-naïve persons with confirmed recent HIV-1 infection diagnosed in Poland, in the years 2008-2010. Proviral DNA was amplified, sequenced, and screened for the TDR mutations in the pol gene fragments coding for the whole protease and the initial 256 residues of the reverse transcriptase. The frequency of sequences with at least one TDR mutation was 11.3%. In four (7.5%) sequences at least one resistance mutation related to reverse transcriptase inhibitors was identified, and in further two (3.8%) sequences one mutation related to protease inhibitors' resistance was present. The moderate rate of TDR highlights the need for a continuous surveillance and resistance testing among treatment-naïve individuals to optimize treatment effects within a country.

High percentage of recent HIV infection among HIV-positive individuals newly diagnosed at voluntary counseling and testing sites in Poland.

To gain insight into HIV transmission we estimated the proportion of those recently infected. We examined data from HIV-positive patients and a random 10% sample of HIV-negative patients tested at Voluntary Counseling and Testing sites in Poland in 2006. Archived samples from positive patients were tested by three assays to differentiate recent from long-standing infection. Using logistic regression, we examined the association of recent infection (at least one assay) with age, sex, HIV exposure category, and the interval between self-reported HIV exposure and previous HIV test. Of 13,511 tests, 154 (1.1%) were HIV positive, representing 19.7% (n=783) of new diagnoses in Poland in 2006. Demographic and behavioral data were linked for 95, of whom 45 (47%) were recently infected and 1,001 were HIV negative. New diagnoses were more likely to be injectors (17% vs. 2%), men who have sex with men (MSM) (37% vs. 12%), and less frequent condom users (7.8% vs. 14% always) compared to HIV negatives. The median number of partners during the past 12 months was one and two among positives and negatives, but was higher among MSM-four and three, respectively. Ever injectors were less likely to be recently infected (adjusted OR=0.15, 95%CI=0.03-0.73). Having two or more sexual partners in the past 12 months was an independent predictor of recent infection (4.01, 1.4-11.49). We found no evidence that age or sex predicted recent infection. These data reinforce health education campaigns for safe sex messages, especially among MSM. They also suggest, albeit based on a subset of new diagnoses, that interventions should not be limited to selected age/sex groups.

Molecular epidemiology of recent HIV-1 infections in southern Poland.

The genetic diversity of human immunodeficiency virus type 1 (HIV-1) offers an opportunity to track the development of the epidemic across different populations. Viral pol gene fragments from 55 individuals of Polish origin with recent HIV-1 infection identified in 2008-2010 in four Polish cities were analyzed. Viral sequences were compared with sequences from 100 individuals (reference group) infected before 2004. Viral spread among groups with different HIV transmission categories was compared using a phylogenetic approach. The majority of sequences from individuals with recent infection were subtype B (93%) within which four transmission clusters (18% of samples) were detected. Samples from men infected through sex between men and from persons infected through injecting drugs were broadly separated (P < 0.0001), while samples from individuals infected by heterosexual contacts were dispersed uniformly within phylogenetic tree (P = 0.244) inferred from viral sequences derived from individuals infected recently and the reference group. The percentage of samples from persons infected by heterosexual contacts which clustered with samples from men infected through sex between men was not significantly higher for those with recent infection (47%), compared to the reference group (36%). In conclusion, men infected by sex between men and individuals infected through injecting drugs appear to form separate HIV transmission networks in Poland. The recent spread of HIV-1 among persons infected with subtype B by heterosexual contacts appears to be linked to both these groups.

Association between the PRNP 1368 polymorphism and the occurrence of sporadic Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a rare transmissible neurodegenerative disorder. The etiology of sporadic form of CJD remains unsolved. In addition to the codon 129 polymorphism, polymorphisms in the non-coding region of PRNP are considered as important factors in sCJD development. To assess a possible association between PRNP 1368 SNP and sCJD, we compared the genotype, allele and haplotype frequencies of the 1368 SNP among 46 sCJD patients of Dutch origin with the respective frequencies in healthy controls. We detected a significant association between sCJD and 1368T/T genotype. A significant difference was also observed in 1368 alleles' distribution. In the haplotype analysis, haplotype 1368C-129G was associated with decreased risk of sCJD in Dutch population. Our findings support the hypothesis that genetic variations in the regulatory region of the PRNP gene may influence the pathogenesis of sCJD.

Association of the PRNP regulatory region polymorphisms with the occurrence of sporadic Creutzfeldt-Jakob disease.

The prion protein (PrP) plays a central role in the pathogenesis of Creutzfeldt-Jakob disease and other transmissible spongiform encephalopathies (TSEs). Mutations in the coding region of the prion protein (PRNP) gene are linked to inherited forms of TSEs whereas aetiology of sporadic CJD (sCJD) remains obscure. It remains unclear whether the primary DNA sequence at non-coding region of PRNP gene influences development of the sCJD. Several recent reports showed non-coding region polymorphisms associated with sCJD but other could not support those findings. To test the hypothesis that there is a relationship between SNPs polymorphisms of PRNP non-coding regions and susceptibility to sCJD, we compared the primary structure of the regulatory region of the PRNP in 45 Dutch sCJD patients and in 135 healthy controls. We found a significant linkage of +310 C allele (OR 0.27, 95% CI 0.09-0.77; P = 0.009) and +310G/C genotype (OR 0.33, 95% CI 0.11-0.98; P = 0.048) with sCJD. No differences in frequencies of genotypes and allele of -101C/G and +258 G/A polymorphisms were found between sCJD patients and controls. We found two haplotypes protecting from sCJD (C-V in block 1 and G-C in block 2) and one susceptible haplotype for sCJD (G-G in block 2). Our findings support the hypothesis that polymorphism in the regulatory region of the PRNP gene may play an important role in the pathogenesis of sCJD.

Current and future assays for identifying recent HIV infections at the population level.

The precise diagnosis of recent human immunodeficiency virus (HIV) infection is crucial for estimating HIV incidence, defined as the number of new infections in a population, per person at risk, during a specified time period. Incidence assessment is considered to be a tool for surveillance, public health and research. Differentiating recent from long-term HIV infections is possible thanks to the evaluation of HIV-specific immune response development or viral markers measurement. Several methods that enable the recognition of recent HIV-1 infection with the use of a single blood specimen have been developed, and their value for use in population level studies has been demonstrated. However, they are still inadequate due to a variable window period and false recent rates among HIV clades and across populations. Application of these assays at an individual level is far more questionable because of person-to-person variability in the antibody response and the course of HIV infection, and because of the prospective regulatory approval requirements. In this article we review the principles and the limitations of the currently available major laboratory techniques that allow detection of recent HIV infection. The assays based on the alteration of serological parameters, as well as the newest method based on an increase of HIV genetic diversity with the progress of infection, are described.