Kristi Huik

CCL3L1 Copy Number Is a Strong Genetic Determinant of HIV Seropositivity in Caucasian Intravenous Drug Users

BACKGROUND A high copy number of CCL3L1, the most potent human immunodeficiency virus (HIV)-suppressive chemokine, associates with reduced HIV susceptibility. Whether CCL3L1 influences acquisition of multiple blood-borne infections (eg, hepatitis C virus [HCV], HIV, and hepatitis B virus [HBV] infections), which occur commonly among injection drug users (IDUs), is unknown. METHODS We determined CCL3L1 copy number by real-time polymerase chain reaction among 374 Caucasian IDUs from Estonia; 285 were HCV positive, 208 were HIV positive, 177 were HCV and HIV positive, and 57 were HCV and HIV negative. RESULTS In univariate and multivariate analyses, HCV and HBV seropositivity and duration of IDU each strongly predicted HIV seropositivity. A high CCL3L1 copy number (>2) was associated with an 80% reduced risk of acquiring HIV infection after adjusting for age, sex, HCV and HBV status, CCR5-Delta32 polymorphism, and IDU duration (odds ratio, 0.20; 95% confidence interval, 0.09-0.45). By contrast, CCL3L1 gene dose did not influence HCV seropositivity. Among HCV-positive IDUs, there was a 3.5-fold overrepresentation and 65% underrepresentation of a high CCL3L1 copy number among HCV-positive, HIV-negative subjects and HCV-positive, HIV-positive subjects, respectively. CONCLUSION Among IDUs with extensive exposure to HCV and HIV, CCL3L1 copy number is a major determinant of HIV seropositivity but not of HCV seropositivity. The contrasting distribution of a protective high CCL3L1 copy number among HCV-positive, HIV-negative IDUs versus HCV-positive, HIV-positive IDUs may reflect that HIV preferentially selects for subjects with a low CCL3L1 gene dose.

Genetic relatedness of coagulase-negative Staphylococci from gastrointestinal tract and blood of preterm neonates with late-onset sepsis.

Background: Coagulase-negative staphylococci (CoNS) are the first colonizers of gastrointestinal tract (GIT) and the commonest cause of late-onset sepsis (LOS) in preterm neonates. Intravascular catheters are considered a major source of CoNS bacteremia. However, several cases of LOS remain without an identified source. To elucidate whether GIT could be a potential source of invasive strains, we aimed to assess the molecular similarity between CoNS from blood and GIT in preterm neonates with LOS. Methods: Altogether 22 blood and 53 GIT isolates collected from 22 neonates with LOS caused by CoNS (Staphylococcus haemolyticus in 13, Staphylococcus epidermidis in 7 and Staphylococcus hominis in 2 patients) were included. Rectal swabs were collected twice weekly from birth, but only isolates obtained before LOS were analyzed. S. epidermidis isolates were typed by multilocus variable number of tandem repeats analysis and multilocus sequence typing, S. haemolyticus by pulsed-field gel electrophoresis. Results: Eighteen of 22 neonates had the same CoNS species in GIT and bloodstream; all these isolates from them (altogether 18 blood and 28 GIT isolates) underwent typing. The genotypic similarity between bloodstream and ≥1 antecedent GIT isolates was observed in 13 of 18 patients—3 of 7 with S. epidermidis and 10 of 11 with S. haemolyticus infection. The concordant GIT isolates were collected 0–7 days before the positive blood culture. Conclusions: The similarity between CoNS from GIT and bloodstream indicates that preterm neonates harbour invasive strains in GIT before LOS. Whether there is a causal relationship between GIT colonization and LOS remains to be elucidated in further studies.

Absence of genotypic drug resistance and presence of several naturally occurring polymorphisms of human immunodeficiency virus-1 CRF06_cpx in treatment-naive patients in Estonia.

All non‐B HIV‐1 subtypes and circulating recombinant forms (CRFs) are characterized by several polymorphisms in protease (PR) region. In addition, in recent years the increasing use of antiretroviral treatment (ART) has rapidly raised the spread of transmitted drug resistance. We aimed to determine the presence of naturally occurring polymorphisms and transmitted drug resistance mutations (DRMs) in ART naïve HIV‐1‐positive subjects in Estonia. A total of 115 drug‐naive HIV‐1‐infected subjects (mean age 27 years; 70% male; 65% infected via intravenous drug use and 34% by heterosexual contact) were enrolled. Viral genomic RNA from plasma was directly sequenced in PR, revertase (RT), and envelope (env) regions. Phylogenetic analysis of RT and env regions revealed that 89% and 3% of sequenced viruses belonged to CRF06_cpx and subtype A1, respectively, and 6% were described as unique recombinants (signed A1‐06) between CRF06_cpx and subtype A1 viruses. No primary DRMs were found in PR or RT regions indicating the absence of transmitted drug resistance. The most common polymorphisms in the PR region were K14R, M36I, H69K, and L89M seen in 96%, 100%, 99%, and 100%, respectively. The clinical relevance of these polymorphisms in terms of success of ART has to be monitored in future clinical studies. J. Med. Virol. 81:953–958, 2009.

Association between TLR3 rs3775291 and resistance to HIV among highly exposed Caucasian intravenous drug users.

BACKGROUND TLR3 recognizes dsRNA and triggers immune responses against RNA and DNA viruses. A polymorphism in TLR3, rs3775291 (Leu412Phe), has been associated with the increased susceptibility to enteroviral myocarditis, protection against tick-borne encephalitis virus and HIV-1 infection. We investigated Caucasian intravenous drug users (IDUs) and blood donors in order to evaluate the associations between TLR3 genotypes and susceptibility to HIV infection. MATERIALS AND METHODS A total of 345 Caucasian IDUs were recruited, 50% of them were HIV positive, 89% HCV and 77% HBV positive. Based on their history of needle sharing, 20 of the HIV negative IDUs were classified as highly exposed HIV seronegatives (HESNs), 68 as non-HESNs and 85 as unexposed. The control group consisting of 497 blood donors tested negative for all three viruses. TLR3 rs3775291 were determined by using TaqMan Allelic Discrimination Assay. RESULTS The TLR3 rs3775291 T allele frequency was similar among the HIV negative and HIV positive IDUs and blood donors - 36%, 31% and 34%, respectively. The frequency of persons possessing at least one TLR3 rs3775291 T allele was significantly higher in HESNs compared with blood donors and HIV positive IDUs (80% vs. 55%; p=0.037 and 80% vs. 53%; p=0.031, respectively). In the univariate analysis, persons who possessed at least one T allele had reduced odds of being HIV seropositive (OR=0.29, 95% CI=0.09-0.90). This association remained significant (OR=0.25, 95% CI=0.07-0.87) after the adjustment for other co-variates (HCV, HBV serostatus and duration of intravenous drug use). CONCLUSIONS The TLR3 rs3775291 T allele has a protective effect against HIV infection among HESNs IDUs.

Emerging transmitted drug resistance in treatment-naïve human immunodeficiency virus-1 CRF06_cpx-infected patients in Estonia.

Abstract Human immunodeficiency virus (HIV)-1 transmitted drug resistance in the drug-naïve population is of growing relevance in Estonia, where the number of antiretroviral (ARV) treatment-experienced subjects has been exponentially increasing during the last 10 y. The aim of this study was to estimate the rate of transmitted drug resistance among newly diagnosed subjects in Estonia in 2008. Genotypic resistance testing for viral genomic RNA was conducted for 201 subjects tested HIV-positive between 1 April and 30 November 2008. Of 145 genotyped viral strains in newly diagnosed patients, 123 were CRF06_cpx, 2 were subtype A1 and 3 were subtype B; in 17 cases viral sequences revealed recombinant structures similar to CRF06_cpx, subtype A1 and CRF02_AG. Resistance mutations were found in 8 (5.5%) virus strains, and 3 strains were resistant to at least 2 ARV classes. A total of 2.8% of sequences harboured mutations indicating nucleoside/nucleotide reverse transcriptase inhibitor resistance (M41L, M184V, M184I, T215C and T215D), 2.1% non-nucleoside reverse transcriptase inhibitor resistance (K103N, P225H) and 2.8% protease inhibitor resistance (M46I, L90M). These data suggest the need to extend genotypic HIV-1 drug resistance testing to newly diagnosed HIV-positive subjects to prevent potential ARV treatment failure.

Influence of interleukin 10 polymorphisms -592 and -1082 to the HIV, HBV and HCV serostatus among intravenous drug users

BACKGROUND Interleukin 10 (IL-10) is a multifunctional cytokine produced by macrophages, monocytes, and T-helper cells. Two polymorphisms at positions -592 and -1082 have been associated with HIV susceptibility. However, their associations with susceptibility to HIV and its co-infections among intravenous drug users (IDUs) are largely unknown. METHODS A total of 345 IDUs were recruited. Of the 173 HIV negative IDUs, 20 were classified as highly exposed HIV seronegative subjects (HESNs). A control group consisted of 496 blood donors; all HIV, HCV, and HBV negative. The IL-10-592C/A and -1082A/G were determined using TaqMan allelic discrimination assay. RESULTS Of the IDUs, 50% were HIV positive, 89% HCV positive, 67% HBV positive and 41% had triple infection. IL-10-592C allele and -1082A allele were the most common and the -1082AG/-592CC was the most common genotype pair. All HESNs exhibited -1082A allele as compared to 81.4% of the HIV positive IDUs and 79% of donors (p=0.029 and p=0.019, respectively). None of HESNs had GG/CC genotype pair compared with 18.6% of HIV positive IDUs and 21.0% of donors (p=0.029 and p=0.019, respectively). The possession of -592AC and genotype pair AG/AC were associated with the decreased odds of HBV infection (OR=0.28; 95% CI 0.09-0.87; p=0.028 and OR=0.19; 95% CI 0.06-0.61; p=0.052, respectively). CONCLUSIONS The presence of low producing IL-10-1082A and -592A alleles and their containing genetic variants protect highly exposed IDUs against acquisition of HIV and HBV infections.

First report of Wohlfahrtiimonas chitiniclastica from soft tissue and bone infection at an unusually high northern latitude

Wohlfahrtiimonas chitiniclastica is a rare human pathogen mostly associated with parasitic flies. This is the report on W. chitiniclastica infection in the soft tissue and bone at a 58°N latitude in the northern temperate climate zone. The importance of correct identification of clinically relevant bacteria is highlighted.

Characterization of Integrase Region Polymorphisms in HIV Type 1 CRF06_cpx Viruses in Treatment-Naive Patients in Estonia

Natural polymorphisms of HIV-1, often associated with drug resistance, are widely described in protease and reverse transcriptase regions but data on their presence in the integrase region, especially in non-B subtypes, are still very limited. We aimed to characterize naturally occurring polymorphisms in the integrase region in 104 treatment-naive and 10 treatment-experienced patients infected predominantly with HIV-1 CRF06_cpx and its recombinant with subtype A1 and/or CRF03_AB viruses. No primary drug resistance mutations against integrase inhibitors were found, but resistance-associated polymorphisms such as V72I, L74I, V201I, and T206S were seen in more than 90% of viruses. Substitutions E157Q and E157K, associated with raltegravir resistance, were found in only two CRF06_cpx strains. We conclude that similar to other HIV-1 non-B subtypes, the CRF06_cpx and its recombinants with subtype A1 and CRF03_AB are rich in integrase region natural polymorphisms, which may impact the development of resistance against integrase inhibitors.

Group A rotavirus genotypes circulating prior to implementation of a National Immunization Program in Estonia

Group A rotaviruses (RVA) are a major cause of acute gastroenteritis in children ≤ 5 y worldwide which could be prevented with two recently introduced vaccines – monovalent Rotarix (live-attenuated G1P[8] strain) and pentavalent RotaTeq (human-bovine reassortant containing serotypes G1, G2, G3, G4 and P[8]). Prior to implementation of vaccines into national immunization program we aimed to describe RVA genotype distribution in hospitalized children aged < 5 y in Estonia during 2007–2008. A total of 671 children with confirmed RVA gastroenteritis from three major pediatric hospitals were prospectively enrolled. G- and P-genotypes were detected from 124 stool samples by semi-nested reverse transcription-PCR. Severity of disease was assessed using Clark scoring system. The majority of cases (65%) occurred in infants aged 7 to 24 mo and were of moderate severity (mean Clark score 12.1 (SD 3.2)). The prevailing strain was G2P[4] (34.7%), causing significantly more cases than G4P[8] (12.9%), G1P[8] or G9P[8] (both 4.0%), G3P[8] (1.6%). Yearly differences in genotype distribution occurred, as G2P[4] (52.8%) dominated in 2007, but G4P[8] (26.9%) in 2008. One third of strains remained non-typeable. The distribution of RVA genotypes in Estonia differs from that seen in other Central and Eastern European countries, although one should bear in mind the large proportion of P-untypeable strains and natural fluctuations of dominating RVA genotypes. Nevertheless, considering the high genotype-independent efficacy of the vaccines, introduction of national immunization should be considered.

Design and structure of the Estonian HIV Cohort Study (E-HIV)

Abstract Background: Estonia is experiencing the new Eastern Europe human immunodeficiency virus (HIV) epidemic, with the highest incidence of new infections in the EU. We describe demographic changes, HIV-related laboratory parameters and co-infections during the concentrated HIV epidemic using the Estonian HIV Cohort Study (E-HIV) database, founded in 2009. Methods: All 3750 subjects in the E-HIV database on December 31, 2013 were included. Subjects were divided into risk groups: people who inject drugs (PWIDs), sexual transmission (heterosexual/homosexual), and other (perinatal) or unknown risk group. Subjects diagnosed before 2009 (first period) and after (second period) were analyzed separately. Results: The mean age at diagnosis has increased from 22.8 years (interquartile range (IQR) = 19.5–27.2) to 29.7 years (IQR = 25.3–36.2) (p < 0.001) between the first and second periods. PWIDs were younger than other transmission groups (23.2 vs 27.1; p < 0.001). There is a statistical difference in the route of transmission among genders, with overall increasing sexual transmission. The most common AIDS-defining illness was tuberculosis (0.5%). HIV/hepatitis C (HCV) co-infection was diagnosed in 42% of cases. The population median CD4 + cell count at diagnosis has declined over the years; in total 53% have been late presenters. Half of the patients are receiving antiretroviral treatment (cART). The most common combinations are nucleoside reverse transcriptase inhibitor (NRTI) backbone plus protease inhibitors (PIs) (57%) or NRTI backbone + non-NRTIs (42%). Conclusion: The E-HIV enables us to fill the gap in the lack of data on the course of the new Eastern European HIV epidemic. These data demonstrate that the HIV epidemic in Estonia is moving from PWIDs to the general population, suggesting that prevention measures and testing guidelines should be revised.