Detection of HIV-1 matrix protein p17 in sera of viremic and aviremic patients.

People living with human immunodeficiency virus type 1 (HIV-1), even if successfully treated with a combined antiretroviral therapy, display a persistent inflammation and chronic immune activation, and an increasing risk of developing cardiovascular and thrombotic events, cancers, and neurologic disorders. Accumulating evidence reveals that biologically active HIV-1 proteins may play a role in the development of these HIV-1-associated conditions. The HIV-1 matrix protein p17 (p17) is released and accumulates in different organs and tissue where it may exert multiple biological activities on different target cells. To assess a role of p17 in different HIV-1-related pathological processes, it is central to definitively ascertain and quantitate its expression in a large number of sera obtained from HIV-1-infected (HIV-1+) patients. To this aim, we developed a specific and highly sensitive p17 capture immunoenzymatic assay. Data obtained highlight a heterogeneous expression of p17 in blood of tested patients, with patients who were negative or displayed from low to relatively high p17 blood concentrations (range from 0.05 to 7.29 nM). Moreover, we found that blood p17 concentration was totally independent from the viremic status of the patient. This finding calls for monitoring HIV-1+ patients in order to evaluate a possible correlation between p17 amount in blood and the likelihood of developing HIV-1-related pathological conditions.

Genome-wide association studies of response and side effects to the BNT162b2 vaccine in Italian healthcare workers: Increased antibody levels and side effects in carriers of the HLA-A*03:01 allele.

The remarkable variability of response to vaccines against SARS-CoV-2 is apparent. The present study aims to estimate the extent to which the host genetic background contributes to this variability in terms of immune response and side effects following the administration of the BNT162b2 vaccine. We carried out a genome wide association study (GWAS) by genotyping 873 Italian healthcare workers who underwent anti-SARS-CoV-2 vaccination with the BNT162b2 vaccine and for whom information about anti-SARS-CoV-2 spike antibodies titers and vaccine side effects were available. The GWAS revealed a significant association between the HLA locus and the anti-SARS-CoV-2 Spike antibodies level at 2 months following the first dose of vaccine (SNP: rs1737060; p = 9.80 × 10-11 ). In particular, we observed a positive association between the antibody levels and the presence of the HLA-A*03:01 allele. The same allele was found associated with a 2-2.4-fold increased risk of experiencing specific side effects such as fever, chills and myalgia and a 1.5-1.8-fold increased risk of joint pain, nausea, fatigue, headache and asthenia, independently of age and sex. This study confirms that the heterogeneity in the immune response to the BNT162b2 vaccine and in its side effects are at least partially influenced by genetic variants. This information, integrated with individual biological and lifestyle-related correlates, could be of use in the definition of algorithms aimed at the identification of subjects in which the administration of additional vaccine doses would be particularly beneficial to maintain immunity against the virus.

Traceability of SARS-CoV-2 transmission through quasispecies analysis.

During COVID-19 pandemic, consensus genomic sequences were used for rapidly monitor the spread of the virus worldwide. However, less attention was paid to intrahost genetic diversity. In fact, in the infected host, SARS-CoV-2 consists in an ensemble of replicating and closely related viral variants so-called quasispecies. Here we show that intrahost single nucleotide variants (iSNVs) represent a target for contact tracing analysis. Our data indicate that in the acute phase of infection, in highly likely transmission links, the number of viral particles transmitted from one host to another (bottleneck size) is large enough to propagate iSNVs among individuals. Furthermore, we demonstrate that, during SARS-CoV-2 outbreaks when the consensus sequences are identical, it is possible to reconstruct the transmission chains by genomic investigations of iSNVs. Specifically, we found that it is possible to identify transmission chains by limiting the analysis of iSNVs to only three well-conserved genes, namely nsp2, ORF3, and ORF7.

Timing and implications for immune response to vaccine in SARS-CoV-2 breakthrough infections.

COVID-19 vaccines elicit a strong anti-S antibodies response. We aim to describe antibody titers in peri-vaccination SARS-CoV-2 infections. This is a retrospective longitudinal single-cohort study. Serological tests were performed at the time of the first SARS-CoV-2 vaccine dose (T0) and 60 (T1), 120 (T2), and 240 (T3) days after. The study included 4,682 subjects. Group A had the infection without an anti-S Ig response. Group B and C seroconverted for anti-N Ig between T0 and T1 and between T1 and T2, respectively. Group D was persistently anti-N Ig negative. Group B showed an initial sub-optimal response, reaching the highest titer at T3. Those who received the second dose 120 days after the infection had higher titers compared to those who received it 21 days after the first dose. The immune response depends on the number and the timing of vaccine doses, highlighting the need for a more personalized approach to vaccination.

The Effect of the Immunization Schedule and Antibody Levels (Anti-S) on the Risk of SARS-CoV-2 Infection in a Large Cohort of Healthcare Workers in Northern Italy.

Given their occupational risk profile, HCWs were the first to receive anti-SARS-CoV-2 vaccination. However, breakthrough infections remained common, mainly sustained by new SARS-CoV-2 variants of concern (VOCs) that rapidly spread one after another in Italy. Evidence suggests that the measured level of anti-SARS-CoV-2 antibodies does not clearly predict the level of protection conferred by either natural infection or vaccine-induced immunization, highlighting the need for further study on the diversity in susceptibility to SARS-CoV-2 infection. The present study aimed to characterize different risk profiles for SARS-CoV-2 infection in HCWs who had recently received the booster dose, and who were classified according to their immunization profile. The very small number of workers infected during the 8 months following the primary-cycle administration represents proof of the vaccine's effectiveness against non-omicron strains. The comparison among different immunization profiles showed that hybrid immunization (vaccine plus natural infection) elicits higher antibody levels. However, hybrid immunization does not always provide better protection against reinfection, thus suggesting that the immunization profile plays a major role as a virus-host interaction modifier. Despite the high resistance to the reinfection, the peri-booster infection had a not-neglectable infection rate (5.6%), this further reinforcing the importance of preventive measures.

SARS-CoV-2 Breakthrough Infections: Incidence and Risk Factors in a Large European Multicentric Cohort of Health Workers.

BACKGROUND: The research aimed to investigate the incidence of SARS-CoV-2 breakthrough infections and their determinants in a large European cohort of more than 60,000 health workers. METHODS: A multicentric retrospective cohort study, involving 12 European centers, was carried out within the ORCHESTRA project, collecting data up to 18 November 2021 on fully vaccinated health workers. The cumulative incidence of SARS-CoV-2 breakthrough infections was investigated with its association with occupational and social-demographic characteristics (age, sex, job title, previous SARS-CoV-2 infection, antibody titer levels, and time from the vaccination course completion). RESULTS: Among 64,172 health workers from 12 European health centers, 797 breakthrough infections were observed (cumulative incidence of 1.2%). The primary analysis using individual data on 8 out of 12 centers showed that age and previous infection significantly modified breakthrough infection rates. In the meta-analysis of aggregated data from all centers, previous SARS-CoV-2 infection and the standardized antibody titer were inversely related to the risk of breakthrough infection (p = 0.008 and p = 0.007, respectively). CONCLUSION: The inverse correlation of antibody titer with the risk of breakthrough infection supports the evidence that vaccination plays a primary role in infection prevention, especially in health workers. Cellular immunity, previous clinical conditions, and vaccination timing should be further investigated.

Ex-vivo study about antimicrobial effectiveness of phytic acid against Enterococcus faecalis into root canals.

BACKGROUND: Endodontic failure is due to the persistence of microorganisms, especially Enterococcus faecalis, which have become resistant to disinfection measures. Sodium hypochlorite has been traditionally used, whereas phytic acid, a natural irrigant, needs to be further investigated. METHODS: This ex-vivo study compared the antibacterial effectiveness of 0.9% saline solution, 5% sodium hypochlorite and 5% phytic acid against Enterococcus faecalis ATCC 29212 into the apical root canal third of 96 single-rooted extracted teeth, after 1-minute push-and-pull irrigation - a basic irrigation technique. Survived microorganisms were evaluated both through a traditional colony-forming-unit count and introducing the viability PCR, which precisely detects only DNA from intact cells: dead and damaged cells were excluded thanks to a propidium monoazide dye. RESULTS: The culture methods showed that 5% sodium hypochlorite (median: 0 CFU/mL) has a significant greater antibacterial effectiveness (P<0.001) compared both to 0.9% saline solution (median: 4.76 CFU/mL) and 5% phytic acid (median: 0.25 CFU/mL). However, 5% phytic acid proved to be significantly more effective (P<0.001) than 0.9% saline solution. The viability PCR did not reveal a significant difference between 5% sodium hypochlorite (median: 4.12×104 survived bacteria) and 0.9% saline solution (median: 8.45×104 survived bacteria). Five percent phytic acid (median: 0.83×104 survived bacteria) was significantly more effective than both 0.9% saline solution (P<0.001) and 5% sodium hypochlorite (P<0.001). CONCLUSIONS: The findings suggest that 5% phytic acid works against root canal bacteria even with a basic irrigation technique and viability PCR seems to lead to more reliable and sensitive data rather than the culture methods.

Immune Responses to SARS-CoV-2 Infection and Vaccine in a Big Italian COVID-19 Hospital: An 18-Month Follow-Up.

OBJECTIVES: This is a longitudinal prospective study which was designed to assess the trend of anti-SARS-CoV-2 antibodies targeting the Spike (anti-S) and Nucleocapside protein (anti-N) viral antigens over a 9-month period after the administration of an anti-SARS-CoV-2 vaccine in a big COVID-19 hospital located in Northern Italy. PARTICIPANTS: 7411 vaccinated workers were included in a linear mixed-effect model analysis performed to model the anti-S decay over the 9 months following the vaccination, during serological screening performed approximately 2, 4, and 9 months following the first jab administration. Serological tests performed in the 9 months preceding vaccine administration were retrospectively analysed to identify the burden of infections occurring before vaccination. RESULTS: The serological assays were used for monitoring the antibody titres during the observational period. Vaccination significantly reduced the rate of infection and elicited a specific humoral response, which lasted during the whole observational period (9 months). A decay was observed in all considered subgroups. At 35 weeks, workers with no history of pre-vaccine infection showed a significantly lower anti-S titre (-2522 U/mL on average (-2589.7 to -2445.7)); younger workers showed significantly higher anti-S titres (140.2 U/mL on average (82.4 to 201.3)). Only seven immunocompromised workers did not show significant levels of anti-S antibodies; three of them, all females, showed a specific T-cell response. CONCLUSIONS: Comparing the 9-month periods before and after the first vaccine dose, a significant reduction in infection rate was observed (1708 cases vs. 156). Pre-vaccine infection, especially if contracted during the first pandemic wave, greatly enhanced the response to vaccination, which was significantly affected also by age both in extent and duration (inversely related). A gender effect on the T-cell immune response was observed in a small group of workers who did not produce antibodies after vaccine administration.

Serosurvey in BNT162b2 vaccine-elicited neutralizing antibodies against authentic B.1, B.1.1.7, B.1.351, B.1.525 and P.1 SARS-CoV-2 variants.

In this study, we show that BNT162b2 vaccine-elicited antibodies efficiently neutralize SARS-CoV-2 authentic viruses belonging to B.1, B.1.1.7, B.1.351, B.1.525 and P.1 lineages. Interestingly, the neutralization of B.1.1.7 and B.1.525 lineages was significantly higher, whereas the neutralization of B.1.351 and P.1 lineages was robust but significantly lower as compared to B.1 lineage. Following our findings, we consider that the BNT162b2 vaccine offers protection against the current prevailing variants of SARS-CoV-2.

Serological Response to SARS-CoV-2 in Health Care Workers Employed in a Large Tertiary Hospital in Lombardy, Northern Italy.

BACKGROUND: COVID-19 pandemic is requesting unprecedented efforts by health-care workers (HCWs) in all countries, and especially in Italy during the first semester of 2020. METHODS: This is a retrospective, observational study conducted at the Spedali Civili General Hospital, in Brescia, Northern Italy during the SARS CoV-2 pandemic in the first semester of 2020. Serum samples from HCWs were tested for SARS-CoV-2 spike protein-specific antibodies. An online survey was used to collect demographic, clinical, and epidemiological data. RESULTS: Of the 1893 HCWs included, 433 (22.9%) were found seropositive for SARS-CoV-2 IgG. The cumulative prevalence of SARS-CoV-2 infection (antibodies production or past positive RT-PCR on nasal/throat swab) was 25.1% (475/1893). Fifty-six out of 433 (13%) seropositive participants declared to have been asymptomatic during the study period. The development of COVID-19 signs or symptoms is the main determinant of seropositivity (OR: 11.3, p < 0.0001) along with their duration and severity. 40/290 (14.5%) HCWs with documented positive RT-PCR during the study period did not show any detectable antibody response. IgG levels positively correlate with age, COVID-19-compatible signs and symptoms experienced and their duration. CONCLUSIONS: In this study, carried out in one of the most affected areas in Europe, we demonstrate that most HCWs with COVID-19 related symptoms develop a spike protein-specific antibodies with potential neutralizing effect.

Rotary versus reciprocating shaping files in bacterial elimination from long oval canals.

A comparison of the abilities of rotary versus reciprocating files to eliminate viable Enterococcus faecalis populations from the long oval root canals of extracted human teeth. Fifty teeth were contaminated and randomly distributed into two groups (n = 25 each): BT-RaCe group and WaveOne group. Two microbial samples were obtained from each tooth before (S1) and after (S2) instrumentation. The CFUs from the S1 and S2 measurements were calculated and compared between the groups. Both groups showed significantly fewer CFUs in the S2 samples (P < 0.001). In the S2 intragroup comparison, BT-RaCe resulted in significantly fewer CFUs than WaveOne (P = 0.010). In the direct comparison between the rotary multiple file shaping system and the reciprocating single-file system, the multiple file system was more efficient at reducing the microbiological load of viable E. faecalis from long oval root canals.

Streptococcus Pneumoniae Detection Long Time After Death in a Fatal Case of Waterhouse-Friderichsen Syndrome.

We report a fatal case of Waterhouse-Friderichsen syndrome in a 64-year-old man. The diagnosis, suspected during the autopsy (performed 63 hours after death), was confirmed through the successful detection of Streptococcus pneumoniae DNA and antigens in samples (blood and liver) collected during the autopsy. These results conformed with blood cultures performed antemortem, which became available only the day after the autopsy. The case underlines the need to collect biological material (liver and blood samples) during autopsy for microbiological investigations, although the collection is performed a long time after the death, suggesting that a liver sample works for DNA and liver and blood work for Streptococcus pneumoniae antigen detection.

Comparative analysis of SAF, Protaper Next and BT-Race in eliminating Enterococcus faecalis from long oval canals: An ex vivo study.

Comparison of the ability of newly designed rotary files to eliminate viable Enterococcus faecalis populations from long oval root canals of extracted human teeth to that of the self-adjusting file (SAF). One hundred caries-free, single-rooted, long oval teeth were contaminated with E. faecalis. The teeth were randomly distributed into four groups (n = 25) as follows: G.1, manual; G.2, SAF; G.3, ProTaper Next; and G.4, BT-Race. Two microbial samples were obtained from each tooth with sterile paper points, (s1) before and (s2) after instrumentation. The relative reduction in colony-forming units (CFUs) from s1 to s2 measurements was calculated and compared among the groups using parametric Kruskal-Wallis one-way anova on ranks and Dunn's method (a = 0.05). The results indicated a descending order of the groups with regard to efficacy as follows: BT-Race, Next, SAF and manual. The statistical analysis showed that the relative percentage reduction (RR) of CFUs was lower in the manual group than in the other groups, while the SAF group showed a significantly lower RR than the BT-Race group (P < 0.05). The efficacy in reduction of the microbiological load of viable E. faecalis from long oval root canals was different between the tested endodontic systems.

The relationship between ABO blood group and cardiovascular disease: results from the Cardiorisk program.

BACKGROUND: The ABO blood group exerts a profound influence on hemostasis, and it has hence been associated with the development of thrombotic cardiovascular adverse events. In this study, we evaluated the relationship between the ABO blood group and the risk of cardiovascular disease assessed with the Cardiorisk score. METHODS: All blood donors aged between 35 and 65 years were enrolled in the Cardiorisk program, which included the assessment of 8 variables (sex, age, total cholesterol, high-density lipoprotein (HDL) cholesterol, plasma glucose, arterial blood pressure, anti-hypertensive therapy and smoking) which were used to generate a score. Individuals with a resulting score ≥20, considered at high cardiovascular risk, underwent additional instrumental tests (chest X-ray, stress electrocardiogram and Doppler ultrasound of supra-aortic trunks) and were closely clinically monitored. RESULTS: Between January 2005 and December 2015, 289 blood donors with Cardiorisk ≥20 were identified, 249 of whom were included in the study with at least 2 years of follow-up. Among these, 36 (14.5%) had instrumental abnormality tests and developed adverse cardiovascular events (10 acute coronary syndrome, 2 cerebral ischemia, 3 cardiac arrhythmia, 8 stenosis of supra-aortic trunks or iliac arteries) during a median follow-up of 5.3 years. In this group of 249 high risk individuals, a statistically significant association (P=0.02) was found between the non-O blood type and the risk of developing subclinical or clinical cardiovascular events (odds ratio, 3.3; 95% CI, 1.1-10.1; P=0.033). CONCLUSIONS: The results of this study underline the both key role of ABO blood group for the risk of developing arterial thrombotic events and the need for including such unmodifiable variable on the scores assessing the thrombotic risk.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection in adolescents in Northern Italy: an observational school-based study.

BACKGROUND: We carried out a study to evaluate the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae genital infections in school-based adolescents in Northern Italy. METHODS: Systematic screening for C. trachomatis and N. gonorrhoeae genital infection was performed in 13th grade students in the province of Brescia, an industrialized area in Northern Italy. Student filled in a questionnaire on sexual behaviour and provided a urine sample for microbiological testing. RESULTS: A total of 2,718 students (mean age: 18.4 years; 59.1% females) provided complete data (62.2% of those eligible). Overall 2,059 students (75.8%) were sexually active (i.e. had had at least one partner), and the mean age at sexual debut was 16.1 years (SD: 1.4). Only 27.5% of the sexually active students reported regular condom use during the previous 6 months, with higher frequency in males than in females (33.8% vs 24.2%). No case of N. gonorrhoeae infection was detected, while C. trachomatis was found in 36 adolescents, with a prevalence of 1.7% (95% CI: 1.2-2.4) among sexually active students, and no statistical difference between females and males (1.9 and 1.4%, respectively). Inconsistent condom use (odds ratio, OR = 5.5) and having had more than one sexual partner during the previous 6 months (OR = 6.8) were associated with an increased risk of Chlamydia infection at multivariate analysis. CONCLUSION: The prevalence of C. trachomatis infection among sexually active adolescents in Northern Italy was low, despite a high proportion of students who engage in risky sexual behaviour. No cases of N. gonorrhoeae infection were identified.