[Anti-pneumococcus, anti-herpes-zoster and anti-papillomavirus vaccinations: experience in programming continuing education courses in local health units in Rome]. / Vaccinazioni anti-pneumococco, anti-herpes-zoster e anti­ papillomavirus: esperienza nella programmazione di corsi di formazione nelle asl di Roma.

The National Vaccine Prevention Plan considers the recommendations for immune prophylaxis in all ages of life. However, compulsory vaccination introduced in 2017 focused the attention on improving global vaccination coverage in infants and children, giving less attention to adult/elderly vaccinations. The immunization of this population is necessary considering the change in the age structure of the population, whose average life expectancy is increasing. Aim of this work was the organization of continuing education courses about anti-Pneumococcus, anti-Herpes-Zoster and anti-Papillomavirus vaccinations to offer an update of knowledge and to discuss the attitudes of health professionals in vaccination centers of the Local Health Units in Rome.

Neisseria gonorrhoeae PIII has a role on NG1873 outer membrane localization and is involved in bacterial adhesion to human cervical and urethral epithelial cells.

BACKGROUND: Protein PIII is one of the major outer membrane proteins of Neisseria gonorrhoeae, 95% identical to RmpM (reduction modifiable protein M) or class 4 protein of Neisseria meningitidis. RmpM is known to be a membrane protein associated by non-covalent bonds to the peptidoglycan layer and interacting with PorA/PorB porin complexes resulting in the stabilization of the bacterial membrane. The C-terminal domain of PIII (and RmpM) is highly homologous to members of the OmpA family, known to have a role in adhesion/invasion in many bacterial species. The contribution of PIII in the membrane architecture and its role in the interaction with epithelial cells has never been investigated. RESULTS: We generated a ΔpIII knock-out mutant strain and evaluated the effects of the loss of PIII expression on bacterial morphology and on outer membrane composition. Deletion of the pIII gene does not cause any alteration in bacterial morphology or sensitivity to detergents. Moreover, the expression profile of the main membrane proteins remains the same for the wild-type and knock-out strains, with the exception of the NG1873 which is not exported to the outer membrane and accumulates in the inner membrane in the ΔpIII knock-out mutant strain.We also show that purified PIII protein is able to bind human cervical and urethral cells and that the ΔpIII knock-out mutant strain has a lower ability to adhere to human cervical and urethral cells. CONCLUSION: Here we demonstrated that the PIII protein does not play a key structural role in the membrane organization of gonococcus and does not induce major effects on the expression of the main outer membrane proteins. However, in the PIII knock-out strain, the NG1873 protein is not localized in the outer membrane as it is in the wild-type strain suggesting a possible interaction of PIII with NG1873. The evidence that PIII binds to human epithelial cells derived from the female and male genital tract highlights a possible role of PIII in the virulence of gonococcus and suggests that the structural homology to OmpA is conserved also at functional level.

Hepatitis B: Epidemiology and prevention in developing countries.

Hepatitis B virus (HBV) infection is a serious global public health problem. The infection may be transmitted through sexual intercourse, parenteral contact or from an infected mother to the baby at birth and, if contracted early in life, may lead to chronic liver disease, including cirrhosis and hepatocellular carcinoma. On the basis of the HBV carrier rate, the world can be divided in 3 regions of high, medium and low endemicity. The major concern is about high endemicity countries, where the most common route of infection remains vertical transmission from mother to child. Screening of all pregnant women and passive immunization with human hepatitis B immunoglobulin are not affordable for many developing countries. The infection rate can be reduced by modifying behavior, improving individual education, testing all blood donations, assuring asepsis in clinical practice and screening all pregnant women. However, availability of a safe and efficacious vaccine and adoption of appropriate immunization strategies are the most effective means to prevent HBV infection and its consequences. The unsolved problem for poorest countries, where the number of people currently infected is high, is the cost of the vaccine. A future challenge is to overcome the social and economic hurdles of maintaining and improving a prevention policy worldwide to reduce the global burden of the disease.

[Survey among female university students on HPV infection epidemiology and prevention]. / Conoscenze sull'infezione da HPV a due anni dall'inizio della campagna vaccinale: indagine tra le studentesse dell'Università di Roma Tor Vergata.

Human papilloma virus (HPV) is one of the most common sexually transmitted infections. The vaccine has the maximum benefit when given before starting sexual activity and its efficacy is proved also in sexually active women in which the incidence of the infection is higher. In 2010 a questionnaire on HPV was administered to 299 female students of University of Rome Tor Vergata. The results compared with those obtained in a similar 2007-08 survey, and with international data, showed that knowledge about HPV is still low, with a negative impact on the acceptance of specific preventive measures.

Proteomics characterization of outer membrane vesicles from the extraintestinal pathogenic Escherichia coli DeltatolR IHE3034 mutant.

Extraintestinal pathogenic Escherichia coli are the cause of a diverse spectrum of invasive infections in humans and animals, leading to urinary tract infections, meningitis, or septicemia. In this study, we focused our attention on the identification of the outer membrane proteins of the pathogen in consideration of their important biological role and of their use as potential targets for prophylactic and therapeutic interventions. To this aim, we generated a DeltatolR mutant of the pathogenic IHE3034 strain that spontaneously released a large quantity of outer membrane vesicles in the culture supernatant. The vesicles were analyzed by two-dimensional electrophoresis coupled to mass spectrometry. The analysis led to the identification of 100 proteins, most of which are localized to the outer membrane and periplasmic compartments. Interestingly based on the genome sequences available in the current public database, seven of the identified proteins appear to be specific for pathogenic E. coli and enteric bacteria and therefore are potential targets for vaccine and drug development. Finally we demonstrated that the cytolethal distending toxin, a toxin exclusively produced by pathogenic bacteria, is released in association with the vesicles, supporting the recently proposed role of bacterial vesicles in toxin delivery to host cells. Overall, our data demonstrated that outer membrane vesicles represent an ideal tool to study Gram-negative periplasm and outer membrane compartments and to shed light on new mechanisms of bacterial pathogenesis.

Identification of a new OmpA-like protein in Neisseria gonorrhoeae involved in the binding to human epithelial cells and in vivo colonization.

Outer membrane protein As (OmpAs) are highly conserved proteins within the Enterobacteriaceae family. OmpA contributes to the maintenance of structural membrane integrity and invasion into mammalian cells. In Escherichia coli K1 OmpA also contributes to serum resistance and is involved in the virulence of the bacterium. Here we describe the identification of an OmpA-like protein in Neisseria gonorrhoeae (Ng-OmpA). We show that the gonococcal OmpA-like protein, similarly to E. coli OmpA, plays a significant role in the adhesion and invasion into human cervical carcinoma and endometrial cells and is required for entry into macrophages and intracellular survival. Furthermore, the isogenic knockout ompA mutant demonstrates reduced recovery in a mouse model of infection when compared with the wild-type strain, suggesting that Ng-OmpA plays an important role in the in vivo colonization. All together, these data suggest that the newly identified surface exposed protein Ng-OmpA represents a novel virulence factor of gonococcus.

Ng-MIP, a surface-exposed lipoprotein of Neisseria gonorrhoeae, has a peptidyl-prolyl cis/trans isomerase (PPIase) activity and is involved in persistence in macrophages.

Macrophage infectivity potentiators (MIPs) are a family of surface-exposed virulence factors of intracellular microorganisms such as Legionella, Chlamydia and Trypanosoma. These proteins display peptidyl-prolyl cis/trans isomerase (PPIase) activity that is inhibited by immunosuppressants FK506 and rapamycin. Here we describe the identification and characterization in Neisseria gonorrhoeae of Ng-MIP, a surface-exposed lipoprotein with high homology to MIPs. The protein is an homodimer with rapamycin-inhibited PPIase activity confirming that it is a functional member of the MIP family. A knock-out strain, generated by deletion of the mip gene in N. gonorrhoeae F62 strain, was evaluated for its role in infection of mouse and human macrophages. We show that Ng-MIP promotes the intracellular survival of N. gonorrhoeae in macrophages, highlighting a possible role of this protein in promoting the persistence of gonococcal infection.

Genetic and functional analysis of the phosphorylcholine moiety of commensal Neisseria lipopolysaccharide.

Phosphorylcholine (ChoP) is a common surface feature of many mucosal organisms, including Neisseria spp., in which it is present exclusively on pili of pathogenic Neisseria and on the lipopolysaccharide (LPS) of commensal Neisseria (Cn). Its presence in Cn has been confirmed by nuclear magnetic resonance. It appears that choline is the main source for the production of ChoP by Cn. We have sequenced a locus, containing four genes (licA-D) with 47-73% identity to the lic1 locus of Haemophilus influenzae (Hi) and 21-40% identity to lic genes in Streptococcus pneumoniae, involved in the production and incorporation of ChoP. The arrangement of the Cn genes and the presence of CAAT repeats, responsible for phase variation of ChoP expression, resemble Hi and differ from S. pneumoniae. Cn DNA flanking the lic locus contains genes ilvE and NMA2149 with >85% identity to the pathogenic Neisseria genes. However, there are no lic genes in the corresponding location or elsewhere in pathogenic Neisseria. This suggests either the loss of the locus from pathogenic Neisseria or a horizontal transfer of genes to Cn, perhaps from H. influenzae spp. As in Hi, ChoP enhances adherence to and invasion of human epithelial cells via the receptor for platelet-activating factor. However, ChoP expression also increases susceptibility to serum killing mediated by complement and C-reactive protein. Taken together, these observations support the hypothesis that the ability of many organisms to switch off ChoP expression rapidly represents an important adaptation to different environments encountered during the colonization/infection process and that the ChoP moiety apparently synthesized by distinct means in pathogenic and commensal Neisseria represents an advantage in the colonization properties of these bacteria.

Dihydroaeruginoic acid synthetase and pyochelin synthetase, products of the pchEF genes, are induced by extracellular pyochelin in Pseudomonas aeruginosa.

The siderophore pyochelin of Pseudomonas aeruginosa is derived from one molecule of salicylate and two molecules of cysteine. Two cotranscribed genes, pchEF, encoding peptide synthetases have been identified and characterized. pchE was required for the conversion of salicylate to dihydroaeruginoate (Dha), the condensation product of salicylate and one cysteine residue and pchF was essential for the synthesis of pyochelin from Dha. The deduced PchE (156 kDa) and PchF (197 kDa) proteins had adenylation, thiolation and condensation/cyclization motifs arranged as modules which are typical of those peptide synthetases forming thiazoline rings. The pchEF genes were coregulated with the pchDCBA operon, which provides enzymes for the synthesis (PchBA) and activation (PchD) of salicylate as well as a putative thioesterase (PchC). Expression of a translational pchE'-'lacZ fusion was strictly dependent on the PchR regulator and was induced by extracellular pyochelin, the end product of the pathway. Iron replete conditions led to Fur (ferric uptake regulator)-dependent repression of the pchE'-'lacZ fusion. A translational pchD'-'lacZ fusion was also positively regulated by PchR and pyochelin and repressed by Fur and iron. Thus, autoinduction by pyochelin (or ferric pyochelin) and repression by iron ensure a sensitive control of the pyochelin pathway in P. aeruginosa.