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In this paper, we have evaluated the diagnostic utility of three antigenic regions of the Mycoplasma pneumoniae P1, P30, and MPN456 gene products in order to replace the soluble, whole-cell bacterial extract in serological assays. Antigenic regions, being previously identified as B-cell epitopes, were used individually or assembled in a recombinant chimeric antigen by genetic engineering. Paired serum samples from 47 patients with M. pneumoniae infection and from 39 subjects with a clinical picture of atypical pneumonia but without a defined diagnosis of M. pneumoniae infection were included. Immunoglobulin G (IgG) antibodies against epitopes carried by recombinant antigens were measured by performing recombinant enzyme-linked immunosorbent assays (Rec-ELISAs). Rec-ELISA results were compared to those obtained by a commercial assay using the whole-cell Mycoplasma antigen. Our study demonstrates that all IgG Rec-ELISAs using recombinant antigens have better sensitivity with respect to the commercial assay. Furthermore, we show that the use of chimeric antigens improve the performance of the assays. The use of recombinant antigens is effective in distinguishing M. pneumoniae-infected patients from uninfected individuals and shows that immunoassays based on recombinant antigens could provide the basis for standardized commercial tests for the serodiagnosis of M. pneumoniae diseases.

Mycoplasma pneumoniae is the leading cause of atypical pneumonia in children and young adults. Bacterial colonization can occur in both the upper and the lower respiratory tracts and take place both endemically and epidemically worldwide. Characteristically, the infection is chronic in onset and recovery and both humoral and cell-mediated mechanisms are involved in the response to bacterial colonization. To identify bacterial proteins recognized by host antibody responses, a whole-genome M. pneumoniae library was created and displayed on lambda bacteriophage. The challenge of such a library with sera from individuals hospitalized for mycoplasmal pneumonia allowed the identification of a panel of recombinant bacteriophages carrying B-cell epitopes. Among the already known M. pneumoniae B-cell antigens, our results confirmed the immunogenicity of P1 and P30 adhesins. Also, the data presented in this study localized, within their sequences, the immunodominant epitopes recognized by human immunoglobulins. Furthermore, library screening allowed the identification of four novel immunogenic polypeptides, respectively, encoded by fragments of the MPN152, MPN426, MPN456 and MPN-500 open reading frames, highlighting and further confirming the potential of lambda display technology in antigen and epitope discovery.

GOLFIG-1 chemo-immunotherapy is a new translational anticancer regimen based on the combined use of gemcitabine, oxalipatin, levofolinic acid and infusional 5-fluorouracil together with the subcutaneous administration immunoadjuvant cytokines (GM-CSF and ultra low dose IL-2). This regimen, tested in a phase II trial, was safe and very active in patients with metastatic colorectal carcinoma and it has been shown to have powerful immunobiological activity. Treatment with the GOLFIG regimen resulted in the induction of a colon cancer specific cell mediated immune response associated with a significant reduction in the percentage of peripheral regulatory T (T(reg)) cells, a very immunosuppressive lymphocyte subset which is commonly over-represented in cancer patients. These cells are able to prevent the occurrence of autoimmunity in response to immunological stimuli, thus their malfunctioning has been associated with the occurrence of auto-immune diseases but may also be responsible for more efficient anticancer immune reaction. In this manuscript we describe a clinical case concerning a patient with metastatic colon carcinoma who responded to the GOLFIG regimen, showed symptoms of autoimmunity [Discoid Lupus Erythematosus (DLE)] and had a very long survival.

GOLF is a triple translational combination chemotherapy regimen with gemcitabine, oxaliplatin, and 5-fluorouracil (5-FU) (plus levofolinic acid), cytotoxic drugs currently used in the treatment of pancreatic carcinoma. Considering its promising anti-tumor effects in patients with gastroenteric malignancies, we carried out the present study to investigate its toxicity and anti-tumor activity in patients with advanced pancreatic carcinoma. Twenty-seven patients were enrolled in the study, 15 males and 12 females with an average age of 61 years and a performance status (ECOG)

The study aims to identify bacteria causing conjunctivitis in a central Italian area and to analyze chemosusceptibility. From 2005 to 2006, 91 conjunctival swabs were collected from acute conjunctivitis cases and screened for common bacteria and fungi. Susceptibility tests were performed on isolates. Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae amounted to 86.2%. Overall, 100% of strains were susceptible to chloramphenicol and 96.6% to quinolones. Conversely, 20.7% of isolates were tetracycline-resistant and, even if all Gram negative isolates were susceptible to gentamicin, the most frequently isolated pneumococci are constitutively resistant. The study provides support for a rational choice of empiric therapy.

Summary Objectives Streptococcus pneumoniae is frequently isolated from carrier children, but it also causes localized and invasive diseases. Increasing incidence of chemoresistance can affect the efficacy of empiric therapy and it motivates interest in primary prophylaxis. The study aims to investigate clinical and microbiological features of paediatric pneumococcal infections in an Italian province. Methods Retrospective clinical analysis of 640 children, hospitalized from 1992 to 2006 with one culture positive for S. pneumoniae , was performed. Chemosusceptibility tests and serotyping were carried out on isolates; statistical analysis was applied to compare variables. Results Overall, 47.8% were carriers, 49% and 3.2% had, respectively, a localized or invasive disease; S. pneumoniae aetiology accounted for 25% of meningitis and 16% of sepsis. On the total isolates, 10.2% were penicillin non-susceptible, 35.15% were erythromycin resistant, with increasing rates over years. Prevalent invasive serotypes were 1 (38.1%) and 7F (9.5%). Conclusions The study sustains pneumococcal disease relevance in children, on the strength of a 15 year observation. Long time period can represent a limit due to population characteristics changing; a selection bias could also be present due to hospitalized only patient analysis. However, we documented variable evolution of chemoresistance and a peculiar serotype spreading, offering microbiological basis for an appropriate clinical approach.

BackgroundThe IgA1 protease ofStreptococcus pneumoniaeis a proteolytic enzyme that specifically cleaves the hinge regions of human IgA1, which dominates most mucosal surfaces and is the major IgA isotype in serum. This protease is expressed in all of the known pneumococcal strains and plays a major role in pathogen's resistance to the host immune response. The present work was focused at identifying the immunodominant regions of pneumococcal IgA1 protease recognized by the human antibody response.ResultsAn antigenic sequence corresponding to amino acids 420–457 (epiA) of theigagene product was identified by screening a pneumococcal phage display library with patients' sera. The epiA peptide is conserved in all pneumococci and in two out of threeS. mitisstrains, while it is not present in other oral streptococci so far sequenced. This epitope was specifically recognized by antibodies present in sera from 90% of healthy adults, thus representing an important target of the humoral response toS. pneumoniaeandS. mitisinfection. Moreover, sera from 68% of children less than 4 years old reacted with the epiA peptide, indicating that the human immune response against streptococcal antigens occurs during childhood.ConclusionThe broad and specific recognition of the epiA polypeptide by human sera demonstrate that the pneumococcal IgA1 protease contains an immunodominant B-cell epitope. The use of phage display libraries to identify microbe or disease-specific antigens recognized by human sera is a valuable approach to epitope discovery.

To the Editor: Antimicrobial medications classified as macrolides (e.g., erythromycin) and lincosamides (e.g., clindamycin) show strong activity against streptococci and are commonly used to treat community-acquired infections caused by Streptococcus pneumoniae. Moreover, these drugs are the recommended alternatives for patients who cannot tolerate β-lactams. Two main macrolide-resistant S. pneumoniae phenotypes have been reported (1). The first has a high level of resistance to all macrolides, lincosamides, ketolides, and streptogramins B due to ribosomal dimethylation, 23S rRNA mutations, or ribosomal protein mutations (MLSB, MSB, ML, MKSB, and K phenotypes). The second is characterized by a low-level resistance (e.g., MIC 2–4 mg/L) to only 14- and 15-member ring macrolides (M phenotype) because of mef gene–mediated active drug efflux mechanism. In January 2005, an erythromycin-susceptible but clindamycin-resistant pneumococcal strain was obtained from a conjunctival swab of a 10-month-old female outpatient attending the daycare center of the Clinic and Laboratory of Infectious Diseases, Siena University, Siena, Italy. To our knowledge, such a phenotype has not been reported in the international literature for S. pneumoniae, although a similar phenotype of Streptococcus agalactiae was described by Malbruny et al. (2). The S. pneumoniae isolate was identified by standard procedures (3) and confirmed by PCR for the common capsule gene cpsA (4). Serotyping, performed by Quellung reaction, showed a 35F serotype. Susceptibility testing was carried out by disk diffusion and confirmed with E-test according to Clinical and Laboratory Standards Institute standards (5,6) for penicillin, ceftriaxone, ciprofloxacin, erythromycin, clindamycin, linezolid, and quinupristin-dalfopristin. For telithromycin, because an E-test strip was unavailable, a microbroth diluiton method was used. The strain was susceptible to ceftriaxone (MIC 0.125 mg/L), ciprofloxacin (MIC 0.125 mg/L), erythromycin (MIC 0.125 mg/L), linezolid (MIC 1.5 mg/L), quinupristin/dalfopristin (MIC 0.5 mg/L), and telithromycin (MIC

Streptococcus pneumoniae is a causative agent of otitis media, pneumonia, meningitis and sepsis in humans. For the development of effective vaccines able to prevent pneumococcal infection, characterization of bacterial antigens involved in host immune response is crucial. In order to identify pneumococcal proteins recognized by host antibody response, we created an S. pneumoniae D39 genome library, displayed on lambda bacteriophage. The screening of such a library, with sera either from infected individuals or mice immunized with the S. pneumoniae D39 strain, allowed identification of phage clones carrying S. pneumoniae B-cell epitopes. Epitope-containing fragments within the families of the histidine-triad proteins (PhtE, PhtD), the choline-binding proteins (PspA, CbpD) and zinc metalloproteinase B (ZmpB) were identified. Moreover, library screening also allowed the isolation of phage clones carrying three distinct antigenic regions of a hypothetical pneumococcal protein, encoded by the ORF spr0075 in the R6 strain genome sequence. In this work, Spr0075 is first identified as an expressed S. pneumoniae gene product, having an antigenic function during infection.

Susceptibility to macrolides and lincosamides was investigated with 299 consecutive nonduplicate Streptococcus pyogenes clinical isolates collected over a 6-year period (1992 to 1997) from an area of central Italy. During this period, macrolide resistance rates steadily increased (from 9% in 1992 to 53% in 1997; P < 0.001). The increase was caused by isolates with a macrolide-lincosamide-streptogramin B resistance phenotype, carrying mostly erm (B) but also erm (TR) genes, that were not detected in the first 2 years and were detected with increasing prevalence (8, 5, 26, and 37%, respectively) during the following 4 years. During the same period, the prevalence of isolates with a macrolide resistance phenotype, carrying mef (A) determinants, did not vary significantly; on average it was 13%, with modest rate fluctuations in different years and no definite trend. Molecular typing revealed a remarkable clonal diversity among susceptible and resistant isolates and a notable heterogeneity of the genetic environment of the resistance genes. The analysis of clonal diversity in relation with resistance phenotypes and genotypes revealed that increased macrolide resistance rates were due to a complex interplay of different mechanisms, with a relevant contribution played by an “epidemic” spread of genetic elements carrying the erm (B) gene among the circulating streptococcal population.

Severe acute respiratory syndrome coronavirus 2–induced direct cytopathic effects against type I and II pneumocytes mediate lung damage. Krebs von den Lungen‐6 (KL‐6) is mainly produced by damaged or regenerating alveolar type II pneumocytes. This preliminary study analyzed serum concentrations of KL‐6 in patients with coronavirus disease (COVID‐19) to verify its potential as a prognostic biomarker of severity. Twenty‐two patients (median age [interquartile range] 63 [59‐68] years, 16 males) with COVID‐19 were enrolled prospectively. Patients were divided into mild‐moderate and severe groups, according to respiratory impairment and clinical management. KL‐6 serum concentrations and lymphocyte subset were obtained. Peripheral natural killer (NK) cells/µL were significantly higher in nonsevere patients than in the severe group (P = .0449) and the best cut‐off value was 119 cells/µL. KL‐6 serum concentrations were significantly higher in severe patients than the nonsevere group (P = .0118). Receiver operating characteristic analysis distinguished severe and nonsevere patients according to KL‐6 serum levels and the best cut‐off value was 406.5 U/mL. NK cell analysis and assay of KL‐6 in serum can help identify severe COVID‐19 patients. Increased KL‐6 serum concentrations were observed in patients with severe pulmonary involvement, revealing a prognostic value and supporting the potential usefulness of KL‐6 measurement to evaluate COVID‐19 patients' prognosis.

Staphylococcus aureus is a major pathogen in both community and hospital settings. It is a significant etiological agent to treat in healthcare-related infections due to both its ability to cause invasive infection as well as to form biofilm on biomaterials and the high prevalence of resistance to first line antibiotics. The most challenging preventive strategy is vaccine development to guarantee a full and durable protection from staphylococcal diseases in all different high-risk populations, even if the lack of a known correlate of protection from S. aureus is a major hindrance to this effort. We aimed to review the most recent advances in the field of vaccinology against S. aureus, highlighting the potential for future application of the different experimental vaccine types. Several vaccines have completed their preclinical phase of development and others have been tested in humans, however no successful phase III clinical trial has yet been completed.

Purpose Aim of this study is to identify bacteria causing conjunctivitis in a central Italian area and to analyze their chemosusceptibility. Methods From 2005 to 2006, 91 conjunctival swabs were collected from acute conjunctivitis cases who were examined in the primary eye care unit at the "S. Maria alle Scotte" Hospital in Siena. All swabs collected were screened for common bacteria and fungi. Susceptibility tests were performed on isolates. Results Isolated bacteria were Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae for an amount of 86.2%. Overall, 100% of strains were susceptible to chloramphenicol and 96.6% to quinolones. Conversely, 20.7% of isolates were tetracycline-resistant and, even if all Gram negative isolates were susceptible to gentamicin, more frequently isolated pneumococci are constitutively resistant. Conclusion Acute “red eye” is one of the commonest reasons for consultation with primary eye care physicians; in the majority of cases an acute bacterial conjunctivitis is diagnosed, the pathogens most frequently responsible are Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus. Guidelines on the management of conjunctivitis recommend antibiotic routine use where bacterial infection is suspected. This study provides a support in rational choice of empiric therapy with distinct regional preferences in the topical agent to be used.

Erythromycin resistance rates were found to be increased, from 7.1 in 1993 to 32.8% in 1997, among community-acquired Streptococcus pneumoniae isolates from the Siena area of central Italy. Most of the erythromycin-resistant isolates carried ermAM determinants and were also resistant to josamycin and clindamycin, whereas a minority (5.8%) carried mefA determinants and remained susceptible to the latter drugs.