The clinical significance of carbapenem-resistant Klebsiella pneumoniae rectal colonization in critically ill patients: from colonization to bloodstream infection.

PURPOSE: To highlight the clinical significance of carbapenem-resistant Klebsiella pneumoniae (CRKP) rectal colonization by examining the risk factors for CRKP rectal colonization and subsequent bloodstream infection (BSI) in critically ill patients. METHODOLOGY: Prospective study of CRKP rectal colonization in an intensive care unit (ICU) during a 39-month period. CRKP strains isolated from both the blood cultures and corresponding rectal specimens (n=96) of patients were screened by PCR for the presence of antibiotic resistance-associated genes. Molecular analyses were conducted to investigate the clonal relatedness of CRKP strains from the rectal and blood specimens. RESULTS: Among the 498 patients, 226 were rectally colonized by CRKP, 48 of whom developed a CRKP BSI. The median time from hospital admission to the detection of CRKP rectal colonization was 8 days, while the median time from colonization to BSI was 4 days. The duration of ICU stay, patient/nurse ratio and prior use of antianaerobic antimicrobials were associated with CRKP rectal colonization. No specific factor was associated with BSIs in the colonized patients. The blaKPC-2 gene was detected in all 96 strains, which were all classified as sequence type ST-258. Representative pairs (n=48) of CRKP strains colonizing and infecting the same patient shared the same pulsotype. CONCLUSION: Our results indicate that hospitalized patients become infected with their colonizing strains, supporting the strong association between colonization and BSI. Limiting antianaerobic antimicrobial administration, reducing the duration of ICU stay and maintaining a low patient/nurse ratio are possible strategies to restrict rectal CRKP colonization in ICUs.

Comparing Abbott m2000 RealTime HIV test and Roche COBAS Ampliprep/COBAS Taqman HIV test, v2.0 in treated HIV-1 B and non-B subjects with low viraemia.

Viral load testing is a valuable tool in HIV clinical care and research. Discrepancies among diverse viral load assays, especially with regard to non-B HIV-1 subtypes have been reported. Our study aimed to explore the impact of HIV subtype (B versus non-B) on the agreement between CAP/CTM, v2.0 and m2000 RealTime in treated HIV patients, focusing on low viral loads (<200 copies/ml). Our findings indicate that there is a significant difference in the performance of the compared assays in the low-viremic range and non-B subtypes, suggesting that a single assay should be used for follow-up.

NK and NKT Cell Depletion Alters the Outcome of Experimental Pneumococcal Pneumonia: Relationship with Regulation of Interferon-γ Production.

Background. Natural killer (NK) and natural killer T (NKT) cells contribute to the innate host defense but their role in bacterial sepsis remains controversial. Methods. C57BL/6 mice were infected intratracheally with 5 × 10(5) cfu of Streptococcus pneumoniae. Animals were divided into sham group (Sham); pretreated with isotype control antibody (CON) group; pretreated with anti-asialo GM1 antibody (NKd) group; and pretreated with anti-CD1d monoclonal antibody (NKTd) group before bacterial challenge. Serum and tissue samples were analyzed for bacterial load, cytokine levels, splenocyte apoptosis rates, and cell characteristics by flow cytometry. Splenocyte miRNA expression was also analyzed and survival was assessed. Results. NK cell depletion prolonged survival. Upon inhibition of NKT cell activation, spleen NK (CD3-/NK1.1+) cells increased compared to all other groups. Inhibition of NKT cell activation led to higher bacterial loads and increased levels of serum and splenocyte IFN-γ. Splenocyte miRNA analysis showed that miR-200c and miR-29a were downregulated, while miR-125a-5p was upregulated, in anti-CD1d treated animals. These changes were moderate after NK cell depletion. Conclusions. NK cells appear to contribute to mortality in pneumococcal pneumonia. Inhibition of NKT cell activation resulted in an increase in spleen NK (CD3-/NK1.1+) cells and a higher IFN-γ production, while altering splenocyte miRNA expression.

West Nile virus seroprevalence and behavioral risks in HIV-1 infected individuals, Northern Greece, 2011.

OBJECTIVES: This study sought to assess the West Nile Virus (WNV) seroprevalence and behavioral risk factors for WNV infection in HIV-1 infected individuals in Northern Greece in 2011. METHODS: We prospectively enrolled 91 HIV-1 consecutive patients followed up in the HIV clinic of the AHEPA University Hospital in the period from November to December 2011. Serum samples were tested for the presence of WNV IgG antibodies. All subjects were administered a standardized questionnaire to evaluate for risk factors for WNV infection. RESULTS: WNV IgG antibodies were detected in three subjects (3.3%, 95% CI 0.7-9.3%), two of whom were of African origin. The prevalence of WNV antibodies in HIV patients of Greek origin was 1.2% (95% CI: 0.03% - 6.3%). In the sample surveyed, 53.6% (95% CI: 42.4% to 64.5%) were aware of WNV prevention measures; 2.2% reported no implementation of prevention measures, whereas 46.1% implemented at least three measures. Approximately one half of the patients reported outdoor activities for more than two hours from dusk to dawn. None of the IgG-positive patients reported any symptoms compatible with WNV disease during the season at risk. CONCLUSIONS: Among native Greek HIV patients, the WNV seroprevalence is 1.2%. A considerable proportion of patients was aware of WNV prevention measures and implemented some of these. HIV patients and other categories of immunocompromised patients are at increased risk of neuroinvasive disease, and widespread implementation of prevention measures should be strongly encouraged in this patient population.

Cellular HIV type 1 DNA levels are equivalent among drug-sensitive and drug-resistant strains in newly diagnosed and antiretroviral naive patients.

The emergence of resistance against current antiretroviral drugs to human immunodeficiency virus type 1 (HIV-1) is an increasingly important concern to the continuous success of antiretroviral therapy to HIV-1-infected patients. In the past decade, a number of studies reported that the prevalence of transmitted drug resistance among newly diagnosed patients has reached an overall 9% prevalence worldwide. Also, a number of studies using longitudinal HIV-1 patient study cohorts demonstrated that the cellular HIV-1 DNA level in peripheral blood mononuclear cells (PBMCs) has a prognostic value for the progression of HIV-1 disease independently of plasma HIV-1 RNA load and CD4 count. Using a previously established molecular-beacon-based real-time PCR methodology, cellular HIV-1 DNA levels were quantified in newly diagnosed and antiretroviral-naive patients in Northern Greece recruited between 2009 and 2010 using a predefined enrolling strategy, in an effort to investigate whether there is any relationship between cellular HIV-1 DNA levels and HIV-1 transmitted drug resistance. As part of the same study, DNA sequences encoding the env (C2-C5 region of gp120) were also amplified from PBMC-extracted DNA in order to determine the genotypic coreceptor tropism and genetic subtype. Cellular HIV-1 DNA levels had a median of 3.309 log10 HIV-1 copies per 10(6) PBMCs and demonstrated no correlation between cellular HIV-1 DNA levels and HIV-1 transmitted drug resistance. An absence of association between cellular HIV-1 DNA levels with plasma viral HIV-1 RNA load and CD4 levels was also found reconfirming the previously published study. Genotypic analysis of coreceptor tropism indicated that 96% of samples, independently of the presence or not of genotypic drug resistance, were CCR5-tropic. Overall, the findings reconfirmed the previously proposed proposition that transmitted drug resistance does not have an impact on disease progression in HIV-1-infected individuals. Also, CCR5 coreceptor tropism dominance suggests that both drug-resistant and drug-sensitive strains behave similarly in early infection in newly diagnosed patients.

Short communication: molecular epidemiology of HIV type 1 infection in northern Greece (2009-2010): evidence of a transmission cluster of HIV type 1 subtype A1 drug-resistant strains among men who have sex with men.

A prospective molecular epidemiology study of HIV-1 infection was conducted in newly diagnosed and antiretroviral-naive patients in Northern Greece between 2009 and 2010 using a predefined enrolling strategy. Phylogenetic trees of the pol sequences obtained in this study with reference sequences indicated that subtypes B and A1 were the most common subtypes present and accounted for 44.9% and 42.9%, respectively, followed by subtype C (3.1%), CRF02_AG (4.1%), CRF04_cpx (2.0%), and subtypes CRF01_01, F1, and G (1.0%). A high rate of clustered transmission of subtype A1-resistant strains to reverse transcriptase (RT) inhibitors was observed among men having sex with men. Indeed, 15 out of 17 study subjects (88.2%) infected with transmitted drug resistance (TDR) strains were implicated in transmission clusters, 10 of whom (66.7%) were men who have sex with men (MSM), and were also infected with subsubtype A1 strains. The main cluster within subtype A1 (I) included eight men reporting having sex with men from Thessaloniki infected with dual-class RT-resistant strains carrying both T215C and Y181C mutations.

Time trends and correlates of late presentation for HIV care in Northern Greece during the decade 2000 to 2010.

BACKGROUND: The aim of our study was to assess the extent of late presentation for HIV care in Northern Greece during the period 2000 to 2010 and to explore correlations aiming to provide guidance for future interventions. METHODS: HIV-positive patients with no prior history of HIV care at presentation and with a CD4 T cell count within three months from the first confirmatory Western blot result were eligible for this study. Late presentation and advanced HIV disease were defined in concordance with the recommendations of the European Late Presenter Consensus working group. Time trends in presentation status and risk factors linked to late presentation and advanced HIV disease were identified in multivariable logistic regression models. Additional analyses after multiple imputation of missing values were performed to assess the robustness of our findings. RESULTS: The status at presentation was evaluated for 631 eligible HIV-positive individuals. Overall, 52.5% (95% CI: 48.6% to 56.4%) of patients presented late for HIV care and 31.2% (95% CI: 27.6% to 34.8%) presented with advanced HIV disease. Time trends were consistent with an improvement in the presentation status of our study population (p<0.001). Risk factors associated with late presentation in multivariable logistic regression were intravenous drug use, heterosexual HIV transmission, immigrant status and age at diagnosis. CONCLUSIONS: Despite the trend for improvement, a significant proportion of newly diagnosed HIV-positive patients present late for care. Targeted interventions with focus on social groups such as the elderly, persons who inject drugs, immigrants and individuals at risk for heterosexual HIV transmission are mandated.

Molecular epidemiology of chronic hepatitis B virus infection in Greece.

Virological data on chronic hepatitis B virus (HBV) infection in Greece are limited. HBV genotypes, surface antigen (HBsAg) subtypes, and HBsAg "a" determinant mutations among patients infected chronically with HBV, were investigated. Serum samples from 135 HBsAg positive patients were tested. Serologic (HBsAg, anti-HBs, HBeAg, and anti-HBe), virologic (HBV-DNA quantitation) and biochemical markers (serum alanine aminotransferase/ALT and aspartate aminotransferase/AST) were analyzed. HBV genotypes and HBsAg subtypes were determined by partial sequencing of the S gene. Genotyping was performed by using the National Center for Biotechnology Information online Genotyping tool and phylogenetic analysis. Nucleotide sequences were aligned pair wise with ClustalW and phylogenetic trees were constructed by the neighbor-joining method. Sequences were also used to predict HBV HBsAg subtypes. In six patients (4%), simultaneous presence of HBsAg and anti-HBs was determined, whereas 47 patients (35%) were HBeAg positive, 84 (62.5%) were anti-HBe positive, and four patients (3%) were characterized by the simultaneous presence of HBeAg and anti-HBe. Mean ALT was 238 IU/L (standard deviation = 576.84), and HBV-DNA levels ranged from 1.02 × 10(5) to 2.2 × 10(7) IU/ml. Genotype D was predominant (98%), with viral groups D/ayw2 (73%) and D/ayw3 (27%). Group A/adw accounted for 1% of cases. Genotypes B and C were found exclusively in the Chinese immigrants (1%). Single or multiple point mutations were found in 35 cases (26%). Some of the most common mutations occurred at amino acid positions 129, 133, 134, 144, 145, including the "vaccine escape" mutation G145R. Mutations analysis revealed that amino acid substitutions did not affect detection by commercial immunoassays.