Safety of mRNA BNT162b2 COVID-19 (Pfizer-BioNtech) vaccine in children aged 5-11 years: Author's reply to correspondence

Dear Editor, We would like to reply to "Safety of mRNA BNT162b2 COVID-19 (Pfizer-BioNtech) vaccine in children aged 5-11years: Correspondence" regarding our article entitled "Safety of mRNA BNT162b2 COVID-19 (Pfizer-BioNTech) vaccine in children aged 5-11years: Results from an active pharmacovigilance study in central Italy."

Infections and Colon Surgery: Preliminary Results from a Surveillance Program in an Italian Hospital

Surgical site infections (SSIs) represent a valid indicator of the healthcare quality. This study described the preliminary results of one-year active surveillance program on colon surgeries in a hospital in Molise region, central Italy. Patients who had undergone colon surgery according to National Healthcare Safety Network were included. Data on intervention, perioperative antibiotic prophylaxis, and SSIs occurrence were collected. Chi-square and Fisher's Exact test were used to evaluate any association between risk factors and SSIs. Sixty-eight patients (mean age 70.6 years) were included, and 44 (64.7%) were males. The most frequent interventions were right (n = 17, 25.0%) and left (n = 15, 22.0%) hemicolectomy. Surgical interventions were largely elective (n = 43, 63.2%) and with laparotomy (n = 56, 82.4%). During hospital stay, 10 (14.7%) SSIs were detected, including five superficial, three deep and two organ/space infections. Three (4.4%) additional SSIs were detected at post-discharge follow-up, for 13 (19.1%; CI95%: 9.7%-28.5%) total cases detected. Metronidazole plus Ceftriaxone (third generation cephalosporin) was the antibiotics combination mostly used (n = 36, 52.9%) for the perioperative antibiotic prophylaxis within 60 minutes of incision. The study underlines the need of improvements of the practices currently adopted, since SSIs could be significantly reduced through a multimodal strategy generating bundles. As third generation cephalosporins may facilitate resistant strains emergence, for perioperative prophylaxis in clean-contaminated interventions with entry into gastrointestinal tract, Cefazolin plus Metronidazole or only second generation cephalosporin are recommended. Due to the large variability of post-intervention antibiotic therapy, antimicrobial stewardship approach is strictly necessary.

Safety of mRNA BNT162b2 COVID-19 (Pfizer-BioNtech) vaccine in children aged 5-11 years: Results from an active pharmacovigilance study in central Italy

This survey investigated on adverse events after vaccination with mRNA BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine in children aged 5-11 years in central Italy through active surveillance reporting. During December 2021-January 2022, parents of children who undergone vaccination were interviewed using a structured questionnaire. 197 out of 208 contacted parents participated (94.7% response rate), of whom 166 (84.3%) had one child. Of the 229 children, the mean age was 8.9 years, 50.7% were female. 193 (84.3%) had at least one adverse event after the first dose (mean age 9.1 years; 54.4% female), and 146 (73.4%) of 199 after the second (mean age 8.9 years; 54.8% female), which was not administered to 30 children due to previous COVID-19 history. Local symptoms after the first and second dose occurred in 183 (94.8%) and 141 (96.6%) recipients (p = .435), respectively, while systemic reactions in 62 (32.1%) and 34 (23.3%) (p = .074). Mild events were reported by 81.7% and 69.8% children after the first and second dose, followed by moderate (3.9% and 10.6%) and severe (1.3% and 0.5%). After each dose, injection site reactions (79.5% and 68.8%) were the most frequent, followed by headache (13.1%) and lymphadenopathy (8.5%) after the first and second dose, respectively. The adverse events were reported to pediatricians only for 5.7% and 3.9% of children and treated for 17.6% and 15.8%. This is the first report about safety profile through active surveillance of mRNA BNT162b2 among children in Italy, revealing temporary and mild-to-moderate symptoms with no serious events after each vaccine dose.

A Cross-Sectional Study of Untoward Reactions Following Homologous and Heterologous COVID-19 Booster Immunizations in Recipients Seventeen Years of Age and Older

A booster dose after primary COVID-19 vaccination series was considered crucial after the emergence of the B.1.617.2 (Delta) and B.1.1.529 (Omicron) variants. Active surveillance was used to investigate reporting of adverse events post-booster dose of either of the licensed mRNA Comirnaty (Pfizer/BioNTech) or Spikevax (Moderna) vaccines in adult (17 years and older) recipients in central Italy. Eligible participants were enrolled and interviewed via phone using a structured questionnaire. Primary outcomes related to the occurrence of adverse events post-booster were stratified by vaccine, and frequency of local/systemic, mild/moderate/severe events. Of a total of 622 participants interviewed, 554 (89.1%) reported at least one adverse event (88.2% and 92.9% after the Comirnaty or Spikevax vaccine, respectively): 63.4% were female, and 78.5% aged 17 to 64 years, regardless of vaccine. 87.7% and 68.2% of all recipients described at least one local or systemic reaction, respectively: 97.3, 38.6 and 4.7% reported mild, moderate, or severe events, respectively. The most frequent adverse reactions were pain, redness, or swelling at the injection site and fatigue, while malaise and fever significantly occurred after the Comirnaty, and vomiting after the Spikevax booster. Compared to the primary vaccination, lymphadenopathy was more common after the booster (p < 0.001), especially after Comirnaty vaccine. The study findings revealed no serious or unexpected adverse events, and are in agreement with data available on booster dose for both mRNA vaccines. The transient, mild to moderate, and common to very common side reactions reported should be used to reassure potential recipients of the lack of safety concerns.

Public health, personalized medicine, and COVID-19 in the pre-vaccination phase: a narrative review of the literature on unfavorable prognostic factors in Italian patients

OBJECTIVES

to provide an outline of the factors mainly influencing severe disease and fatal outcome among Italian COVID-19 patients in the pre-vaccination phase, also describing the impact of the scenarios driven by variants, vaccines, and available therapies.

DESIGN

a literature search was carried out for peer-reviewed articles searching for COVID-19 and prognosis, including severe disease and death.

SETTING AND PARTICIPANTS

Italian patients with COVID-19.

MAIN OUTCOME MEASURES

the association between risk factors and severe disease and death as the main outcomes was assessed through epidemiological measures, including relative risk, odds ratio, and hazard ratio.

RESULTS

advanced age, obesity, overweight, non-0 blood group, and male gender were the factors more associated with severe disease. Fatal outcome mostly correlated with old age, non-0 blood group, and obesity, together with cardiovascular diseases, diabetes, hypertension, cancer, chronic kidney disease, and acute kidney injury.

CONCLUSIONS

clinical and epidemiological characteristics of the Italian population, integrated with omics data, could be highly valuable to stratify risk of worse prognosis among patients, and to address targeted prevention and treatment interventions.

Alphitobius diaperinus Panzer (Insecta, Coleoptera) in a single house of a broiler production facility as a potential source of pathogenic bacteria for broilers and humans

Pest infestation in any stage can lead to a quality reduction in the finished products. This study aimed to detect Escherichia coli, Salmonella spp., Campylobacter spp., and Staphylococcus aureus in Alphitobius diaperinus adults, and in samples from broiler swabs, administered water and feed collected in a single house from a broiler production facility in central Italy. Three samplings were carried out, each collecting ninety adult beetles for microbial detection in the external, fecal and internal content; ten cloacal swab samples; and one sample of both administered feed and water. Microbiological cultures and biochemical identification were performed on suspected cultures and confirmed by species-specific PCRs. A. diaperinus was abundantly found near the windows, under the manger and in the corners of the facility. Salmonella enterica serovar Cholerasuis was found at the external surface of the beetles, while Staphylococcus xylosus and E. coli in the fecal content. The latter microrganism together with Staphylococcus lentus, S. xylosus and other staphylococcal species were detected in the internal microbiota. E. coli and Campylobacter spp. were observed in cloacal swabs, and S. xylosus in one feed sample. The study findings support evidence for Salmonella spp. and E. coli, and remark that adherence with sanitation rules and biosecurity procedures are required.

Active Surveillance of Adverse Events in Healthcare Workers Recipients After Vaccination with COVID-19 BNT162b2 Vaccine (Pfizer-BioNTech, Comirnaty): A Cross-Sectional Study

In this cross-sectional study, adverse events after the first and second dose of BNT162b2 mRNA (Pfizer-BioNTech, Comirnaty) vaccine against coronavirus disease 2019 were investigated among employees of clinics in central Italy. A 42-items questionnaire was administrated to vaccine recipients. Adverse events were classified based on severity and occurrence as reported in the literature. A descriptive/univariate analysis using Chi-square or Fisher’s Exact tests was performed. Odds ratio (OR) and 95% confidence intervals were calculated to assess risk factors. 340 individuals (61.5% females; median age 49 years) participated. Adverse events were reported by 279 (82%) and 281 (82.6%) individuals as induced by the first and second dose, respectively. Mild reactions were mainly reported (80.9% and 80.3%), followed by moderate (11.8% and 37.1%) and severe (3.8% and 4.7%). Adverse events were identical to those already described as very common (81.8% and 80.6%), although vaccine-coincidental events not cited in the literature were reported by 6% and 15.6% following each dose. Age ≤ 55 years was a risk factor for any adverse event after each injection (ORs: 2.942 and 2.818), as well as female sex for those mild (ORs: 1.856 and 2.818) and common (ORs: 3.452 and 2.145). Findings were consistent with national reports as most of the adverse events were mild and associated with female sex and young age, while investigations are needed for reactions not described elsewhere. Data are useful to support the vaccine safety profile, also because largely targeted healthcare personnel more skilled than general population in self-diagnosis of health-related issues.

A Coronavirus Outbreak Linked to a Funeral Among a Romani Community in Central Italy

Background: The epidemic dynamics of COVID-19 in the Molise region, central Italy, has dramatically changed from the beginning of May 2020, which was when infections were reported amongst Romani people. The aims of this study were to describe the characteristics of an outbreak that occurred in the Romani community and the interventions implemented for control.

Methods: A retrospective analysis of outbreak data was performed to describe the SARS-CoV-2 transmission dynamics.

Results: A young Romani woman was the first case reported and epidemiological investigation established a possible link with the funeral of a deceased member of this community. In total, 150 close contacts within 34 family groups in two cities were traced, and 109 (72.7%) Romani individuals were found to be infected by COVID-19. The patient's median age was 31 years, 58% were female, and the highest (20.2%) incidence occurred in the 0–9 years age group. A total of 26 (23.8%) patients developed typical SARS-CoV-2 symptoms, 15 (57.8%) were hospitalized, and 21 (22.1%) had comorbidities [most commonly hypertension (28.6%) and/or coronary heart diseases (23.8%)]. The outbreak was effectively controlled through compulsory quarantine and enhanced active surveillance.

Conclusions: This is the first study providing insight into COVID-19 transmission dynamics among a Romani population living in Italy. These findings support general conclusions about the role of crowded social gatherings in SARS-CoV-2 spread, the high communicability among close contacts and household settings, and the impact of asymptomatic carriers. These features are of relevance to certain Romani customs where family gatherings are a fundamental pillar of their lives. Although difficulties emerged in interacting with Romani people related to cultural drivers, beliefs, and lifestyle, the outbreak management was effective and should be considered as a valuable model applicable to similar incidents occurring in minority populations.

Pidotimod and Immunological Activation in Individuals Infected with HIV

BACKGROUND

The improvements in HIV infection therapy and the large availability of antiretroviral drugs have led to an increased survival among HIV infected people, and simultaneously to a raised morbidity and mortality due to not-AIDS-related events in this group compared to the general population. An increased systemic inflammation and a persistent immune activation play a pivotal role in determining high rates of non-AIDS comorbidities. In the last years, many natural or synthetic immunomodulatory molecules acting by different mechanisms have been conceived. Pidotimod is a synthetic dipeptide molecule showing immunomodulatory properties. The aim of this pilot study was to evaluate the effects of Pidotimod supplementation on residual inflammation in HIV infected population.

METHODS

Forty HIV positive individuals under cART were enrolled: 30 were treated with Pidotimod supplementation (study group) and 10 served as control group (without Pidotimod supplementation). For all participants, Cystatin C, PCR, ESR, microalbuminuria, TNF-α, INF-γ, IL-4, IL-10, IL1β, IL-18 and IL-2 were measured at enrolment (T0), 4 weeks after of Pidotimod supplementation (T1), and 4 weeks after completing supplementation (T2).

RESULTS

In HIV positive participants treated with Pidotimod, the evaluation of cytokine levels showed that IL-10, IFN gamma, and IL-4 were significantly higher at enrolment compared to the control group. The increase under Pidotimod treatment persisted after supplementation suspension, while the pro-inflammatory cytokines levels were reduced. Salivary IgA also increased during 4 weeks of supplementation and persisted at 4 weeks after completing supplementation. On the other hand, the Cystatin C and microalbuminuria levels decreased over time, at a greater extent the Cystatin C serum levels.

CONCLUSION

The study findings showed that the HIV population receiving Pidotimod achieved a rebalancing of pro-inflammatory and anti-inflammatory cytokines as well as a significant reduction in cystatin C levels. The treatment further allowed for an increase in salivary IgA levels at all the analyzed times, as a secondary event to a remodulation of the immunological status obtained with pidotimod. This approach could represent a new way to design new intervention strategies aimed at improving the persistent immune activation status in the virologically suppressed HIV population.

Healthcare-Associated Infections and Antibiotics Consumption: A Comparison of Point Prevalence Studies and Intervention Strategies

This study compares healthcare-associated infections (HAIs) prevalence and antimicrobial consumption (AMC) from surveys conducted in 2016 and 2019 in an Italian hospital for acute care. HAIs prevalence was 7.1% in both surveys, while patients were under antibiotic treatment slightly increased from 2016 to 2019, from 42.6% to 43.7%, respectively. In the survey of 2016, HAIs risk factors were fatal McCabe score and hospitalization longer than two weeks, while CVC and urinary catheter in that conducted in 2019. In both surveys, CVC and peripheral venous catheter resulted associated to AMC. HAIs and AMC remained stable although the hospital undergone a complexity reduction in the second survey, remarking that critical actions are strictly required implementing infection control practices and antimicrobial stewardship.

Precision Medicine and Public Health: New Challenges for Effective and Sustainable Health

The development of high-throughput omics technologies represents an unmissable opportunity for evidence-based prevention of adverse effects on human health. However, the applicability and access to multi-omics tests are limited. In Italy, this is due to the rapid increase of knowledge and the high levels of skill and economic investment initially necessary. The fields of human genetics and public health have highlighted the relevance of an implementation strategy at a national level in Italy, including integration in sanitary regulations and governance instruments. In this review, the emerging field of public health genomics is discussed, including the polygenic scores approach, epigenetic modulation, nutrigenomics, and microbiomes implications. Moreover, the Italian state of implementation is presented. The omics sciences have important implications for the prevention of both communicable and noncommunicable diseases, especially because they can be used to assess the health status during the whole course of life. An effective population health gain is possible if omics tools are implemented for each person after a preliminary assessment of effectiveness in the medium to long term.

New Delhi metallo-β-lactamase (NDM-1)-producing Klebsiella pneumoniae of sequence type ST11: first identification in a hospital of central Italy

The emergence of novel resistant markers hampers the efficacy of beta-lactam antibiotics to treat infections caused by micro-organisms carrying such resistances. This study investigated the antimicrobial susceptibility pattern, the carpapenem-associated determinants and the molecular epidemiology of Klebsiella pneumoniae showing a New Delhi (NDM) metallo-β-lactamase phenotype, isolated from a patient admitted to intensive care unit of the main hospital for acute care of Molise region, central Italy. Antimicrobial susceptibility was assessed for nineteen antibiotics by disc diffusion and agar dilution methods. Carbapenem-associated resistance determinants were detected through gene-specific amplifications, targeting bla_NDM-1 , bla_SHV and bla_TEM , bla_CTX-M , bla_KPC , bla_VIM , bla_IMP , bla_GES and bla_OXA-48-lixe . Molecular characterization was carried out through multilocus sequence typing. The strain showed a multidrug resistant profile, and PCR and sequencing confirmed the presence of bla_NDM-1 gene. Among the multiple resistance-associated determinants tested, the isolate, which was assigned to the sequence type ST11, only harboured bla_SHV and bla_TEM genes. This is the first report of NDM-1 variant in the regional healthcare setting for acute patients, raising significant concerns about the increase in the antimicrobials resistance spread through a different mechanism from the endemic KPC carbapenemase, and underlining the circulation of a virulent clone never identified before in this area.

Human Papillomavirus Infections, Cervical Cancer and MicroRNAs: An Overview and Implications for Public Health

Human Papillomavirus (HPV) is among the most common sexually transmitted infections in both females and males across the world that generally do not cause symptoms and are characterized by high rates of clearance. Persistent infections due at least to twelve well-recognized High-Risk (HR) or oncogenic genotypes, although less frequent, can occur, leading to diseases and malignancies, principally cervical cancer. Three vaccination strategies are currently available for preventing certain HR HPVs-associated diseases, infections due to HPV6 and HPV11 low-risk types, as well as for providing cross-protection against non-vaccine genotypes. Nevertheless, the limited vaccine coverage hampers reducing the burden of HPV-related diseases globally. For HR HPV types, especially HPV16 and HPV18, the E6 and E7 oncoproteins are needed for cancer development. As for other tumors, even in cervical cancer, non-coding microRNAs (miRNAs) are involved in posttranscriptional regulation, resulting in aberrant expression profiles. In this study, we provide a summary of the epidemiological background for HPV occurrence and available immunization programs. In addition, we present an overview of the most relevant evidence of miRNAs deregulation in cervical cancer, underlining that targeting these biomolecules could lead to wide translational perspectives, allowing better diagnosis, prognosis and therapeutics, and with valuable applications in the field of prevention. The literature on this topic is rapidly growing, but advanced investigations are required to achieve more consistent findings on the up-regulated and down-regulated miRNAs in cervical carcinogenesis. Because the expression of miRNAs is heterogeneously reported, it may be valuable to assess factors and risks related to individual susceptibility.

Molecular Epidemiological Insights into Colistin-Resistant and Carbapenemases-Producing Clinical Klebsiella pneumoniae Isolates

Purpose

Carbapenemases-producing Klebsiella pneumoniae are challenging antimicrobial therapy of hospitalised patients, which is further complicated by colistin resistance. This study describes molecular epidemiological insights into colistin-resistant and carbapenemases-producing clinical K. pneumoniae.

Patients and methods

Cultures collected from 26 hospitalised patients during 2014-2017 in the main hospital in Molise Region, central Italy, were characterized. The minimum inhibitory concentration for 19 antibiotics was determined, including carbapenems and colistin. Prevalence of resistance-associated genes was investigated through PCR, detecting bla _KPC, bla _GES, bla _VIM, bla _IMP, bla _NDM, bla _OXA-48, bla _CTX-M, bla _TEM, bla _SHV, and mcr-1,2,3,4,5,6,7,8. The mgrB gene was also analysed in colistin-resistant strains by PCR and sequencing assays. K. pneumoniae were typed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

Results

Twenty out of 26 K. pneumoniae were phenotypically resistant to carbapenems and 19 were resistant to colistin. All isolates harbored bla _KPC, and bla _SHV, bla _TEM and bla _VIM were further the most common resistance-associated genes. In colistin-resistant strains, mcr-1,2,3,4,5,6,7,8 variants were not detected, while mutations and insertion elements in mgrB were observed in 68.4% (n=13) in 31.6% (n=6) isolates, respectively. PFGE revealed 12 clusters and 18 pulsotypes at 85% and 95% cut-off, while the Sequence Types ST512 (n=13, 50%), ST101 (n=10, 38.5%), ST307 (n=2, 7.7%) plus a novel ST were detected using MLST.

Conclusion

All K. pneumoniae showed a multidrug-resistant phenotype, particularly to carbapenems and colistin. According to national data, bla _KPC was the prevailing carbapenemase, followed by bla _VIM, while bla _TEM and bla _SHV were among the most frequent beta-lactamases. Consistent with previous reports in Italy, ST512 was the most common clone, particularly during 2014-15, whilst ST101 became dominant in 2016-17. Colistin resistance was mainly associated with deleterious mutations and transposon in the mgrB gene. Improvements of surveillance, compliance with infection prevention procedures and antimicrobial stewardship are essential to limit the spread of resistant K. pneumoniae.

A multicentre study on epidemiology and prevention of needle stick injuries among students of nursing schools

INTRODUCTION

Among the health professions with a long period of training, the students of the Nursing Bachelor's Degree are the most exposed to biological risk resulting from accidents, in particular with needles and cutting edges. The aim of the study was to estimate the frequency and the circumstances for the occurrence of needle stick injuries, as a knowledge base for targeted prevention interventions.

METHODS

The study was carried out between May and July 2017 in 11 Universities in Italy and 1 in Albania (associated with the "Tor Vergata" University of Rome). An anonymous semi-structured questionnaire was proposed to 1st (second semester), 2nd and 3rd year students of Nursing Bachelor's Degree.

RESULTS

A total of 2742 questionnaires were collected. The average age of participants was 22.9 years (median 22, range 19-60 years), 73% of whom were females. A total of 381 injuries were reported. Three hundred and sixteen students (11.8%) underwent at least 1 injury (12.7% among females, 9.7% among males); 41 students declared two or more injuries; four students did not report the number of injuries occurred. The first injury occurred, as an average, 17 days after the start of the internship (median 15 days) and, in 25% of the cases, during the first 9 days. The highest percentage of accidents occurred during the first internship (25.3% of the total) and decreased with the progress of the training path. The injuries occurred in 38% of cases during drug preparation, 24% when disposing of sharp devices, 15% while re-capping needles, 13% during blood sampling and 10% in other circumstances. In 51.2% of cases, the needle was not sterile. Among the nursing students who suffered a needle stick injury, 58.1% declared that they had performed the post-exposure prophylaxis. 96% of students stated to be vaccinated against Hepatitis B virus. Amongst the students who had their serological status checked (74%), 18% stated the antibody titre was not protective. 49.8% of students answered to have been trained in advance on the correct procedures to avoid needle stick and cutting edges injuries in each clinical ward attended, 41.2% referred that this occurred only in some wards and 10% in no ward at all.

CONCLUSION

The results of this study show a high percentage of needle stick injuries in students of the Nursing Bachelor's Degree. Therefore, there is a need for careful reflection on the most effective methods of targeted training acquisition of knowledge, skills and behavioural models useful for the exercise of the profession.

Carbapenem-Resistant KPC- and TEM-Producing Escherichia coli ST131 Isolated from a Hospitalized Patient with Urinary Tract Infection: First Isolation in Molise Region, Central Italy, July 2018

In July 2018, a Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli ST131 was isolated from a patient admitted to the Vascular Surgery Unit of the main hospital of Molise region, Central Italy. Sequencing and alignment with the available sequences revealed that the isolate harbored the KPC-2 variant and TEM-1 beta-lactamase. This observation raises great concerns about the spread of carbapenem resistance in national and local settings with high endemicity level of KPC in K. pneumoniae, and underlines the importance of strengthening a proactive surveillance.

A single-arm study to evaluate skin tolerance, effectiveness and adherence to use of an alcohol-based hand rub solution among hospital nurses

Background:

Hand hygiene is considered as the most important strategy for preventing healthcare infections.

Objective:

In this single-arm study, skin tolerance, effectiveness and prolonged efficacy, and adherence to use an alcohol-based hand rub (ABHR) solution among hospital nurses was evaluated.

Methods:

Nurses were recruited in the main hospital of Molise Region, Central Italy. Skin reactions during 12-week follow-up were self-reported by nurses and, when occurring examined by hospital dermatologist. Samples were collected from palms and fingertips before and after ABHR, also at random times during work.

Results:

Dermatological reactions were not reported by 20 nurses (15 female and 5 male, aged 30–59 years) after product use. Microbial counts decreased by 99% (2Log10) in 75%, with higher reduction in palm than fingertips (99% vs 70% respectively). Analysis of six randomly collected samples after 10–20 and 30–40 min from the last use showed a satisfactory prolonged efficacy.

Discussion:

Beyond high effectiveness to reduce transient microbiota, no skin reactions were observed, likely due to the camomile, thyme and eucalyptus extracts contained within the gel. This study, addressing technical questions of a commercialised product, provides useful information for public health authorities faced with a choice of hand disinfectants, evaluating cost-effectiveness and cost-benefit in the light of the huge amount of these products needed at hospital level.

[Biological risk in agriculture and construction workplaces: a survey on perception, knowledge and prevention measures.]

OBJECTIVES

Despite the potential presence in many workplaces, biological risk is little known and largely underestimated, except in healthcare environments. Objectives: To evaluate perception, knowledge and behaviors adopted for protection and prevention of biological risk, related also to the occupational activity, among construction and agricultural workers.

METHODS

Workers were recruited at farms and construction companies of Molise Region, Central Italy, which were visited within the surveillance activities planned by local institutions. A questionnaire was administered to workers to collect sociodemographic and occupational data, and concerning risk perception and knowledge, and awareness of available prevention measures, also related to the work activity.

RESULTS

total of 143 workers (73.4% males, 42.9±10.7 years old) were interviewed, and 56.6% were construction workers. Only 24% of workers believed that infectious diseases could be frequent and health threatening in carrying out the work activities; half of them declared to be exposed to biological hazards, but 70% were unworried. An underestimation of the severity of some pathologies, such as listeriosis, leptospirosis and viral hepatitis emerged, and only 70% of workers believed that tetanus is highly or very highly dangerous for health. Furthermore, 33% of workers said to have scarce or insufficient knowledge of biological risk, and 97.2%, 80.4% and 45.5% were aware that a vaccine is available for tetanus, hepatitis B and A, respectively. All workers undergone the tetanus vaccination and 39.2% the anti-hepatitis B.

CONCLUSIONS

Despite the high probability of exposure to biological agents, the results of the survey revealed a lack of perception and knowledge of the risk, as well as a poor awareness of available preventive measures among construction and agricultural workers. These data point out the need to activate information and training programs on exposure to biological agents and on both emerging and re-emerging infectious diseases potentially related to work activities, and to provide prevention procedures specific for these workplaces.

High resolution melting analysis for the characterization of lineage II Listeria monocytogenes serovars 1/2a and 1/2c based on single nucleotide polymorphisms identification within the Listeria Pathogenicity Island-1 and inlAB operon: a novel approach for epidemiological surveillance

AIMS

A high resolution melting (HRM) assay was developed for characterizing lineage II Listeria monocytogenes based on the amplification and the melting profiles analysis of 81 fragments targeting the region from the prs to ldh loci, including the Listeria Pathogenicity Island-1 (LIPI-1) genes and the inlAB operon.

METHODS AND RESULTS

Real-time PCR and HRM protocols were standardized using 10 replicate assays from L. monocytogenes EGD-e reference strain (serovar 1/2a). Twenty wild-type isolates of serovar 1/2a and two of serovar 1/2c were tested, and differences between EGD-e strain and the wild-type isolates were defined if the melting temperature (Tm ) of an amplicon was not within the lower and the upper limits calculated from replicate testing on EGD-e. The analysis revealed 17 and 19 HRM profiles with respect to prs/LIPI-1/ldh and inlAB target regions (Simpson's Index of Diversity 0·979 and 0·983) respectively. The 1/2c cultures showed 98·1% similarity to melting characteristics with EGD-e, whilst 1/2a isolates had the greatest heterogeneity that was related to inlA, inlB and actA genes. Sequencing of amplicons generating different Tm values from EGD-e confirmed the presence of point mutations.

CONCLUSIONS

This method was useful for L. monocytogenes subtyping based on single nucleotide polymorphisms detection through the melting behaviour analysis of main virulence genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study underlines the effectiveness of HRM in differentiating L. monocytogenes strains with high discriminatory power, thus rendering it useful for epidemiological surveillance.

Procedures in endoscope reprocessing and monitoring: an Italian survey

BACKGROUND

The high diffusion of endoscopes worldwide and the need for effective reprocessing methods requested the development of guidelines and implementation of surveillance procedures at local level.

STUDY DESIGN

In order to collect data on everyday's practice and adherence to available guidelines, endoscopy units from different public institutions were surveyed using a dedicated questionnaire.

METHODS

Between July and November 2015 a survey was carried in 12 main hospitals from 10 different Italian regions, involving 22 endoscopy units. The state of the art of national and international guidelines was investigated to compare the protocols adopted at local level.

RESULTS

In all the surveyed hospitals, the reprocessing activity is based on pre-established protocols in adherence with principal guidelines. Enzymatic detergents, which are recommended by the international guidelines, are used in 55.6% of units and peracetic acid is currently the most widely used chemical disinfectant. Discrepancies were observed in the application of periodic quality controls.

CONCLUSION

Updated guidelines are generally applied in reprocessing practice. Quality controls may represent a critical issue to improve effectiveness and surveillance. The whole of acquired data can promote a positive trend towards the application of best practices.

High Resolution Melting as a rapid, reliable, accurate and cost-effective emerging tool for genotyping pathogenic bacteria and enhancing molecular epidemiological surveillance: a comprehensive review of the literature

INTRODUCTION

Rapid, reliable and accurate molecular typing methods are essential for outbreaks detection and infectious diseases control, for monitoring the evolution and dynamics of microbial populations, and for effective epidemiological surveillance. The introduction of a novel method based on the analysis of melting temperature of amplified products, known as High Resolution Melting (HRM) since 2002, has found applications in epidemiological studies, either for identification of bacterial species or molecular typing, as well as an extensive and increasing use in many research fields. HRM method is based on the use of saturating third generation dyes, advanced real-time PCR platforms, and bioinformatics tools.

OBJECTIVE

To describe, by a comphrehensive review of the literature, the use, application and usefulness of HRM for the genotyping of bacterial pathogens in the context of epidemiological surveillance and public health.

MATERIAL AND METHODS

A literature search was carried out during July-August 2016, by consulting the biomedical databases PubMed/Medline, Scopus, EMBASE, and ISI Web of Science without limits. The search strategy was performed according to the following keywords: high resolution melting analysis and bacteria and genotyping or molecular typing. All the articles evaluating the application of HRM for bacterial pathogen genotyping were selected and reviewed, taking into account the objective of each study, the rationale explaining the use of this technology, and the main results obtained in comparison with gold standards and/or alternative methods, when available.

RESULTS

HRM method was extensively used for molecular typing of both Gram-positive and Gram-negative bacterial pathogens, representing a versatile genetic tool: a) to evaluate genetic diversity and subtype at species/subspecies level, based also on allele discrimination/identification and mutation screening; b) to recognize phylogenetic groupings (lineage, sublineage, subgroups); c) to identify antimicrobial resistance; d) to detect and screen for mutations related to drug-resistance; e) to discriminate gene isoforms. HRM method showed, in almost all instances, excellent typeability and discriminatory power, with high concordance of typing results obtained with gold standards or comparable methods. Conversely, for the evaluation of genetic determinants associated to antibiotic-resistance or for screening of associated mutations in key gene fragments, the sensitivity and specificity was not optimal, because the targeted amplicons did not encompass all the crucial mutations.

CONCLUSIONS

Despite the recent introduction of sequencing-based methods, the HRM method deserves consideration in research fields of infectious diseases, being characterized by low cost, rapidity, flexibility and versatility. However, there are some limitations to HRM assays development, which should be carefully considered. The most common application of HRM for bacterial typing is related to Single Nucleotide Polymorphism (SNP)-based genotyping with the analysis of gene fragments within the multilocus sequence typing (MLST) loci, following an approach termed mini-MLST or Minim typing. Although the resolving power is not totally correspondent to MLST, the Simpson's Index of Diversity provided by HRM method typically >0.95. Furthermore, the cost of this approach is less than MLST, enabling low cost surveillance and rapid response for outbreak control. Hence, the potential of HRM technology can strongly facilitate routine research and diagnostics in the epidemiological studies, as well as advance and streamline the genetic characterization of bacterial pathogens.

Potential testing of reprocessing procedures by real-time polymerase chain reaction: A multicenter study of colonoscopy devices

BACKGROUND

Reprocessing of endoscopes is key to preventing cross-infection after colonoscopy. Culture-based methods are recommended for monitoring, but alternative and rapid approaches are needed to improve surveillance and reduce turnover times. A molecular strategy based on detection of residual traces from gut microbiota was developed and tested using a multicenter survey.

METHODS

A simplified sampling and DNA extraction protocol using nylon-tipped flocked swabs was optimized. A multiplex real-time polymerase chain reaction (PCR) test was developed that targeted 6 bacteria genes that were amplified in 3 mixes. The method was validated by interlaboratory tests involving 5 reference laboratories. Colonoscopy devices (n = 111) were sampled in 10 Italian hospitals. Culture-based microbiology and metagenomic tests were performed to verify PCR data.

RESULTS

The sampling method was easily applied in all 10 endoscopy units and the optimized DNA extraction and amplification protocol was successfully performed by all of the involved laboratories. This PCR-based method allowed identification of both contaminated (n = 59) and fully reprocessed endoscopes (n = 52) with high sensibility (98%) and specificity (98%), within 3-4 hours, in contrast to the 24-72 hours needed for a classic microbiology test. Results were confirmed by next-generation sequencing and classic microbiology.

CONCLUSIONS

A novel approach for monitoring reprocessing of colonoscopy devices was developed and successfully applied in a multicenter survey. The general principle of tracing biological fluids through microflora DNA amplification was successfully applied and may represent a promising approach for hospital hygiene.

Prevalence of anal, oral, penile and urethral Human Papillomavirus in HIV infected and HIV uninfected men who have sex with men

Aims of the study were to evaluate Human Papillomavirus (HPV) and type-specific prevalence in four anatomical sites in HIV infected men who have sex with men (MSM) compared with HIV uninfected MSM. Participants were recruited among the attendees of Infectious Diseases Clinics in Central Italy. A trained medical practitioner collected by interview sociodemographic data and information on medical history, sexual behavior, and drug use. Swabs from anal canal, oral cavity, urethral mucosa, and coronal sulcus were tested for HPV DNA and genotyping. Ninety MSM were enrolled, 45 subjects within each group. Overall, 48.9% MSM were HPV positive and prevalence was higher in HIV infected men (60.0% vs 37.8%, P = 0.035). HPV at multiple anatomic sites occurred in 59.1% MSM, with 34.1% and 22.7% at two and three sites, respectively. Prevalence of anal, coronal sulcus, oral, and urethral HPV was 96.3%, 37%, 21.6%, and 18.5% in HIV infected MSM, and 70.6%, 70.6%, 29.4%, and 23.5% among HIV uninfected. A similar proportion of HIV infected and uninfected MSM (59.2% and 58.8%) carried at least one high-risk genotype. Prevalence of types covered by nonavalent vaccine was 77.8% in HIV infected compared with 82.3% in HIV uninfected MSM. HPV 58 and 16 were mostly detected in HIV positive (43.7% and 31.2%) and negative MSM (50.0% and 40.0%). HPV detection rate underlined the high vulnerability of MSM to acquire multisite infections, characterized by various genotype combinations. Since nonavalent vaccine could have prevented 80% of HPV infections, study findings support the implementation of vaccination programs among MSM.

Biological risk among agriculture and construction workers in Molise Region, Central Italy

BACKGROUND

Biological risk is a significant issue in workplaces due to continuous modification of work organization and condition.

OBJECTIVES

In this pilot study, perception and knowledge of biological risk, as well as adoption of prevention measures were evaluated among construction and agriculture workers.

METHODS

A structured questionnaire was administered to workers to collect socio-demographic and employment information, in addition to data on risk perception and knowledge, and adoption of preventive measures, including those related to work activities.

RESULTS

Fifty-three workers aged 45.3±9.8 years participated in the study, 81% were male, and 70% were construction workers. Approximately 80% of participants declared that infectious diseases are neither frequent nor health-threatening in their occupational activity. The majority of workers considered some diseases, such as hepatitis A and B, leptospirosis and listeriosis, as posing a low risk to their health. Forty-seven % claimed to be unexposed to biohazards at their workplace, and 72% were not worried about them. Ninety-six % of the workers knew about vaccination for tetanus, but only 74% and 36% knew about the availability of vaccination for Hepatitis A and B, respectively. During lifetime, 94% of the workers received at least one vaccination. All workers had undergone tetanus vaccination, but only few received vaccine for influenza, hepatitis B and tuberculosis.

CONCLUSIONS

This pilot study in occupational settings revealed a poor perception of biological risk and a limited awareness of the severity of infectious diseases. Major knowledge gaps existed about the available preventive measures. It is essential to promote safety culture at the workplace also with regard to biological hazards. This requires improving information and education, conducting appropriate studies, and prompting health and safety professional actors to focus on occupational infectious disease problems.

On the role of a coumarin derivative for sensing applications: Nucleotide identification using a micellar system

The recognition of nucleotides is of crucial importance because they are the basic constituents of nucleic acids. The present study is focused on the selective interaction between a novel amphiphilic fluorophore containing coumarin and imidazole, CI (1-methyl-3-(12-((2-oxo-2H-chromen-7-yl)oxy)dodecyl)-1H-imidazol-3-ium bromide), and different nucleotide-monophosphates (NMPs). It was supposed that the solubilization of the low water soluble CI in a micelle system of hexadecyltrimethylammonium chloride (CTAC) would make the coumarin moiety of CI available to the interaction with the water-soluble NMPs. Changes in CTAC critical micelle concentration suggested that CI strongly interacted with the host cationic surfactant, thus forming a positively charged interface enriched with coumarin able to interact with the anionic NMPs. Steady-state fluorescence quenching revealed that CI/CTAC system was capable of distinguish between purine- and pyrimidine-based nucleotides. A modified Stern-Volmer equation permitted the use of a quenching model that accounted for the possible interactions between the micelles and the nucleotides. The data analysis allowed calculating selective parameters that differentiated according to the type of nucleotide either at 25 or 50°C. Our results established the utility of the novel coumarin derivative fluorophore, supported by the simple and suitable micellar systems, as a tool for DNA sensing applications.

High prevalence of human papillomavirus type 58 in HIV infected men who have sex with men: A preliminary report in Central Italy

Human papillomavirus (HPV) infection and type-specific prevalence at anal, oral, coronal sulcus, and urethral mucosa in fifty HIV positive men having sex with men (MSM) were evaluated; patients were enrolled in a non-metropolitan area of Central Italy. Clinical and socio-demographic information, drug, and sexual behaviors were obtained for each participant. HPV was detected by PCR from an overall of 200 specimens, and genotyping was performed by both Restriction Fragment Length Polymorphism analysis and sequencing. HPV DNA was found in 60.0% (n = 30) of HIV positive MSM, and prevalence was higher at anal canal (n = 28, 56.0%) compared to all the other anatomical sites (χ(2) test P < 0.01) of coronal sulcus (n = 11, 22.0%), oral (n = 8, 16.0%), and urethral mucosa (n = 5, 10.0%). We found 63.3% (n = 19) of MSM with at least one high-risk genotype, and HPV-58 was more frequently detected (n = 9, 47.4%) respect to HPV-16 (n = 6, 31.6%). This is the first report on HPV detected at four anatomical sites involved in sexual practices in HIV positive MSM. We found an unusual distribution of oncogenic genotypes with an exceeding prevalence of HPV-58 respect to HPV-16. Hence, the recently licensed nonavalent vaccine should be suitable to prevent a larger number of infections caused by potentially emerging high-risk genotypes.

MicroRNAs expression patterns in the response of poplar woody root to bending stress

The paper reports for the first time, in poplar woody root, the expression of five mechanically-responsive miRNAs. The observed highly complex expression pattern of these miRNAs in the bent root suggest that their expression is not only regulated by tension and compression forces highlighting their role in several important processes, i.e., lateral root formation, lignin deposition, and response to bending stress. Mechanical stress is one of the major abiotic stresses significantly affecting plant stability, growth, survival, and reproduction. Plants have developed complex machineries to detect mechanical perturbations and to improve their anchorage. MicroRNAs (miRNAs), small non-coding RNAs (18-24 nucleotides long), have been shown to regulate various stress-responsive genes, proteins and transcription factors, and play a crucial role in counteracting adverse conditions. Several mechanical stress-responsive miRNAs have been identified in the stem of Populus trichocarpa plants subjected to bending stress. However, despite the pivotal role of woody roots in plant anchorage, molecular mechanisms regulating poplar woody root responses to mechanical stress have still been little investigated. In the present paper, we investigate the spatial and temporal expression pattern of five mechanically-responsive miRNAs in three regions of bent poplar woody taproot and unstressed controls by quantitative RT-PCR analysis. Alignment of the cloned and sequenced amplified fragments confirmed that their nucleotide sequences are homologous to the mechanically-responsive miRNAs identified in bent poplar stem. Computational analysis identified putative target genes for each miRNA in the poplar genome. Additional miRNA target sites were found in several mechanical stress-related factors previously identified in poplar root and a subset of these was further analyzed for expression at the mRNA or protein level. Integrating the results of miRNAs expression patterns and target gene functions with our previous morphological and proteomic data, we concluded that the five miRNAs play crucial regulatory roles in reaction woody formation and lateral root development in mechanically-stressed poplar taproot.

Evaluation of transcription levels of inlA, inlB, hly, bsh and prfA genes in Listeria monocytogenes strains using quantitative reverse-transcription PCR and ability of invasion into human CaCo-2 cells

Listeria monocytogenes virulence depends on the activity of well-characterized virulence factors. In this study, transcription levels of inlA, inlB, hly, bsh and prfA genes in L. monocytogenes strains, and the ability of invasion into CaCo-2 cells were investigated. Serotyping, multiplex-PCR for serovar identification and restriction fragment analysis of inlA were performed. Transcription levels and invasiveness were evaluated by quantitative reverse-transcription PCR and by in vitro assays, respectively. The isolates were of serovars 1/2a, 4b, 1/2c, 1/2b and 3a. Full-length inlA profiles were found for nine of ten clinical isolates, while five of seven cultures from foods showed truncated profile. The analysis of transcription levels of virulence factors encoding genes demonstrated a substantial inter-strain heterogeneity, with clinical strains showing higher levels for almost all genes than isolates from food. A correlation between transcription levels of inlA and inlB, as well as between bsh and prfA, was observed. Significant differences between clinical strains and food isolates in the invasion of CaCo-2 cells were found. Analysis of gene transcription and invasiveness of human cells suggests different virulence phenotypes among L. monocytogenes populations, and this characterization could be a useful tool for risk assessment purposes and for the development of public health strategies.

[Molecular epidemiology of infectious diseases: analytical methods and results interpretation]

Molecular typing and fingerprinting of microbial pathogens represent an essential tool for the epidemiological surveillance, outbreak detection and control of infectious diseases. Indeed, epidemiological investigation without genotyping data may not provide comprehensive information to allow the most appropriate interventions; despite this consideration, some barriers still hamper the routine application and interpretation of molecular typing data. In this paper, the most important methods currently used for characterization of pathogenic microorganisms for microbial source tracking and for the identification of clonal relationships among different isolates, are described according to their principles, advantages and limitations. Criteria for their evaluation and guidelines for the correct interpretation of results are also proposed. Molecular typing methods can be grouped into four categories based on different methodological principles, which include the characterization of restriction sites in genomic or plasmid DNA; the amplification of specific genetic targets; the restriction enzyme digestion and the subsequent amplification; sequence analysis. Although the development and the extensive use of molecular typing systems have greatly improved the understanding of the infectious diseases epidemiology, the rapid diversification, partial evaluation and lack of comparative data on the methods have raised significant questions about the selection of the most appropriate typing method, as well as difficulties for the lack of consensus about the interpretation of the results and nomenclature used for interpretation. Several criteria should be considered in order to evaluate the intrinsic performance and practical advantages of a typing system. However none of the available genotyping methods fully meets all these requirements. Therefore, the combined use of different approaches may lead to a more precise characterization and discrimination of isolates than a single method, especially if used in a hierarchical manner. The interpretation of the molecular results differs according to the typing system's characteristics: for example in the restriction fragments-based analysis, the divergences or the similarity percentages among the profiles are evaluated, whilst the differences in terms of number and intensity of bands are analyzed in the amplification-based approaches. Moreover, a correct interpretation of molecular results significantly depends by other critical factors, such as the comprehension of the typing system and data quality, the microbial diversity, and the epidemiological context in which the method is used. The analysis of PFGE data, considered as the "gold standard", is based on the differences of the number and position of bands patterns, although recent recommendations are now available from the Centers for Diseases Control and Prevention (CDC) for a more accurate interpretation, which also include the evaluation of the gel quality, the genetic diversity of the microorganism, the time and geographical scale of an epidemic event. Future advances in the molecular typing technologies indeed will provide rapid methodological improvements, such as a greater degree of automation, better resolution, higher throughput, and a greater availability of dedicated bioinformatics tools. These factors will all contribute to an increasing application of genotyping methods to better understand the epidemiology of infectious diseases, and to implement, along with the strengthened international and interdisciplinary partnerships, more effective control and prevention strategies for Public Health improvements.

Asthma prevalence and risk factors among children and adolescents living around an industrial area: a cross-sectional study

Background

The exposure to air pollution has negative effects on human health, increasing the risk of respiratory diseases, such as asthma. Few data are yet available on the epidemiology of childhood asthma in some areas of Italy. The aim of the study was to estimate asthma prevalence and related risk factors in children and adolescents residents around the industrial area of Termoli, Molise region, Central-South Italy.

Methods

Prevalence was assessed through the administration of modified ISAAC questionnaires filled out by parents of 89 children and adolescents for the identification of confirmed and probable cases, and by analyzing pediatricians’ databases on drug prescriptions for symptoms control and treatment of assisted population in the study area (n = 1,004), compared to a control area (n = 920) with lower industrialization. The association of asthma with risk factors was evaluated by univariate (Chi-square or Fisher’s Exact test) and regression logistic analysis.

Results

A total of 22 (24.7%) asthmatics were identified, including both confirmed (n = 7; 7.9%) and probable cases (n = 15; 16.8%), most of them (n = 17; 77.3%) resident of Termoli town. All asthma cases were georeferenced based on the residence, however clusters were not found. Using drug prescriptions analysis, a higher prevalence (n = 138; 13.7%) of diagnosed cases was found. Lifetime history of both atopic dermatitis and bronchitis were significantly relateds to asthma cases, as well as an elevated body mass index, whose association is consistent with prevalence data of overweight/obese children living in the study area. Moreover, being resident of the town of Termoli was associated to the occurrence of cases.

Conclusions

Although our data indicated a prevalence concordance with previous national studies in pediatric population, a definitive correlation with environmental industrial factors present in the study area was not established. However, asthma outcome was significantly associated to individuals living in the town of Termoli that, despite the industrial/manufacturing activities, is also subjected to a higher environmental pressure due to the presence of toll road, state highway, railroad, and seaport which may cause air pollution from motor vehicle traffic and increase asthma induction. This study provides hitherto unavailable data on asthma in childhood population living in an industrialized area which was never investigated before, could be part of a systematic review or meta-analysis procedure, might suggest significant findings for larger observational studies, and contribute to complete the frame of disease epidemiology in Italy.

[Vibrio spp. infections of clinical significance and implication for public health]

Vibrio spp. infections still are a Public Health concern. Vibrio spp. can be found in marine, estuarine, and freshwater environments, and can be able to cause diseases in fish, shellfish, mammals, as well as in humans. Since '80 to date, the number of species within the genus increased from 21 to more than 100. The most important is Vibrio cholerae, the etiological agent of the cholera, responsible of seven pandemics; serotypes O1 and O139 can produce cholera toxin, while serotypes non-O1/non-O139 are generally associated with sporadic cholera cases and extraintestinal infections. Vibrio parahaemolyticus is an important cause of gastroenteritis associated with contaminated seafood consumption, whereas Vibrio vulnificus and V. alginolyticus can be related to wound infections or seafoodborne primary septicemia in immunocompromised patients. Disease prevention is mainly based on the application of proper individual or collective preventive measures.

Prevalence and genotype identification of human papillomavirus in women undergoing voluntary cervical cancer screening in Molise, central Italy

We examined the prevalence of HR- and LR-HPV by Linear Array genotyping test in 299 women aged 18-63 years who consecutively visited Molise Region main hospitals for routine Pap smear between February and August 2008. Ninety women were positive for any HPV (30.1%), and 66 for any HR-HPV (22.1%). The most prevalent HR-HPV types were HPV 16 (22.2% of all women with HPV infection), HPV 53 (14.4%), and HPV 66 (14.4%). HPV infections increased from 15.8% in the 18-20 years group to 50.0% in the 21-23 years group and then decreased to 9.1% in those aged 50 years or more (p=0.008). Multiple HPV infections were observed in 15.7% of the study sample (52.2% of all HPV positive). There is a significantly higher prevalence of multiple infections in 18-32 years group women (24.5%) compared with females aged 33 years or more (6.8%) (p<0.005). Current smokers were at increased risk of HPV infection (44.2% of HPV infections compared with 23.5% in never smokers, and 25.3% of multiple HPV infections compared with 11.3%; p=0.001). HR-HPV infections were higher in women never been pregnant (27.1% compared with 7.7%; p=0.001). Oral contraceptive use was completely unrelated to infection. Among the 122 women who had both cytological examination and HPV results, multiple HR-HPV types were found in 36.8% of those with abnormal cervical findings, and in 13.6% of those with normal cervical findings (p=0.05). The results of the present investigation provide further evidence for the notion that cervical HPV infection is more widespread than previously suggested.

Effect of retinoids on follicular cells

It has been demonstrated that topical application of all-trans retinoic acid and other retinoids can alter the hair-growth cycle in the C3H mouse model. The anagen phase is prolonged and the telogen phase is shortened. This effect is similar to the effect of minoxidil on the hair-cycle dynamics in this animal model. The levels of cellular retinoic acid binding protein measured by radioreceptor assay in whole skin of C3H mice were higher during anagen and lower during telogen. Topical application of certain retinoids caused elevated levels of cellular retinoic acid-binding protein (cRABP) in the whole skin homogenates during both phases of the cycle. Of the retinoids tested, those most effective in altering the levels of cRABP in the skin of the mice were also capable of significantly altering the hair-cycle dynamics. There appeared to be a relationship between the ability of retinoid to increase cRABP, increase 3H-thymidine incorporation, and alter the dynamics of the hair cycle. Only cRABP-II is detectable in human cultured dermal fibroblasts and dermal papilla cells. Dermal fibroblasts showed higher amounts of cRABP-II as compared to dermal papilla cells. The difference in cRABP-II expression might explain a distinct response to RA by these two cell populations. Whether the difference in expression of cRABP-II might be of physiologic importance remains to be determined. Treatment of human dermal papilla cells in culture with retinoic acid does not appear to affect proliferation, at least at the doses tested.