Clinical performance of the novel full-genotyping OncoPredict HPV Quantitative Typing assay using the VALGENT framework

Clinical validation of human papillomavirus (HPV) assays according to international criteria is prerequisite for their implementation in cervical cancer screening. OncoPredict HPV Quantitative Typing (QT) assay (Hiantis Srl, Milan, Italy) is a novel full-genotyping multiplex real-time PCR quantitative assay targeting E6/E7 genes, allowing individual viral load determination of 12 high-risk (HR) HPV types. Quality controls for sample adequacy, efficiency of nucleic acid extraction and PCR inhibition are included in the assay. Clinical performance of OncoPredict HPV QT test was assessed as part of the "Validation of HPV Genotyping Tests" (VALGENT-2) framework, consisting of 1300 cervical liquid-based cytology (LBC) samples of women aged between 20 and 60 years who had originally attended for routine cervical screening in Scotland. The clinical accuracy of the OncoPredict HPV QT (index test) for the detection of CIN2+ was assessed relative to the GP5+/6+ Enzyme ImmunoAssay (GP5+/6+ EIA) (comparator test), using noninferiority criteria. Intra- and interlaboratory reproducibility of the assay was assessed on a subpopulation, comprising 526 samples. The relative sensitivity and specificity for OncoPredict HPV QT vs GP5+/6+-PCR-EIA were 1.01 (95% CI: 0.99-1.03) and 1.03 (95% CI: 1.0-1.06) respectively. The P-values for noninferiority were ≤0.001. The intra- and inter-laboratory reproducibility demonstrated a high concordance (>98.7%) with kappas for individual types ranging from 0.66 to 1.00. OncoPredict HPV QT fulfills the international validation criteria for the use of HPV tests in cervical cancer screening.

Accuracy of Human Papillomavirus (HPV) Testing on Urine and Vaginal Self-Samples Compared to Clinician-Collected Cervical Sample in Women Referred to Colposcopy

In the context of cervical cancer prevention, where human papillomavirus (HPV) infection is pivotal, HPV testing is replacing Pap Smear in primary screening. This transition offers an opportunity for integrating self-sampling to enhance coverage. We evaluated the accuracy of HPV testing using self-collected urine and vaginal samples, comparing them to physician-collected cervical swabs. From a cohort of 245 women with abnormal cytology, we collected self-sampled vaginal, urine, and clinician-administered cervical specimens. Employing Anyplex™II HPV28 assay, outcomes revealed HPV positivity rates of 75.1% (cervical), 78.4% (vaginal), and 77.1% (urine). Significant, hr-HPV detection concordance was observed between self-taken cervical samples and clinical counterparts (k = 0.898 for vaginal; k = 0.715 for urine). This study extends beyond accuracy, highlighting self-collected sample efficacy in detecting high-grade cervical lesions. The insight underscores self-sampling's role in bolstering participation and aligns with WHO's goal to eliminate cervical cancer by 2030.

Evaluation of Human Papilloma Virus (HPV) Genotyping and Viral Load Determination as Diagnostic Biomarkers of Cervical Cancer Risk

HPV testing in cervical cancer screening programs offers the possibility of introducing molecular standardized biomarkers for the triage of HPV-positive women. This study aimed to evaluate the role of HPV genotyping and viral load as possible diagnostic biomarkers of high-grade cervical lesions (CIN2+) by performing a preliminary evaluation of a new HPV test. Cervical specimens were obtained from 200 women referred for a colposcopy. Samples were tested using both Anyplex™ II HR-HPV as well as OncoPredict HPV^® Screening (SCR) and quantitative typing (QT). Using a cycle threshold cutoff (Ct) of 36.8 for the SCR assay and 1.27 log₁₀ (viral copies/10⁴ cells) for the QT assay, relative clinical sensitivity for CIN2+ and relative clinical specificity for CIN2- as compared to Anyplex™ II HR-HPV were, respectively, 0.92 and 1.00 for SCR and 1.35 and 1.24 for QT. The distribution of high-risk HPV (HR-HPV) genotypes (p = 0.009) as well as the viral copy numbers (CIN2-: 3.7 log₁₀ (viral copies/10⁴ human cells); CIN2+: 4.3 log₁₀ (viral copies/10⁴ human cells); p = 0.047) were found to differ in women with high- and low-grade cervical lesions, suggesting a possible role of HPV genotyping and normalized viral load as potential biomarkers to identify women at increased risk of cervical lesions.

Evaluation of BD Onclarity™ HPV Assay on Self-Collected Vaginal and First-Void Urine Samples as Compared to Clinician-Collected Cervical Samples: A Pilot Study

The accuracy of available HPV molecular assays on self-samples needs to be evaluated as compared to clinician-collected samples. This pilot study aimed to investigate the BD Onclarity™ HPV assay on vaginal and first-void urine samples. Sixty-four women referred to colposcopy for cervical dysplasia performed a vaginal self-collection and provided a first-void urine sample, after informed consent. A cervical specimen was collected during the clinician examination. All samples were tested using BD Onclarity™ HPV assay on the BD Viper™ LT System. Overall positive agreement (OPA) between cervical and self-sample results was evaluated using Cohen's kappa value (κ). Using a clinical cut-off of 38.3 Ct for HPV 16 and 34.2 Ct for other HR genotypes, compared to cervical sample, the self-collected vaginal sample OPA was 85.9%, and κ = 0.699. Without a clinical cut-off, the OPA was 95.3%, and the κ = 0.890. Data obtained comparing cervical and urine samples showed an OPA of 87.5% with a κ = 0.79 using a clinical cut-off, and an OPA of 90.6% with a κ = 0.776 without a clinical cut-off. Data showed a substantial agreement between both self-collected and clinician-collected samples. A specific clinical cut-off analysis should be considered based on type of sample analysed.

Antibiotic Susceptibility of Environmental Legionella pneumophila Strains Isolated in Northern Italy

Legionella pneumophila is ubiquitous in aquatic environments and responsible for severe pneumonia in humans through inhalation of aerosol containing Legionella spp. Macrolides and fluoroquinolones are frequently used antimicrobials, but treatment failures are increasingly being reported. As susceptibility testing is not routinely performed, this study aimed to determine the minimum inhibitory concentrations (MICs) on 58 environmental Legionella pneumophila strains (24 of serogroup 1 and 34 of non-serogroup 1) isolated in Northern Italy. MICs of azithromycin, erythromycin, ciprofloxacin, levofloxacin, and rifampicin were determined by the microdilution method using buffered yeast extract broth supplemented with α-ketoglutarate (BYEα). Seventy-five percent of Legionella pneumophila isolates showed MIC values below the tentative highest MICs indicated by the European Committee on Antimicrobial Susceptibility Testing (EUCAST); rifampicin was the most active agent with MIC₉₀ values below 0.008 mg/L. Interestingly, one isolate was tested and found to be PCR-positive for the azithromycin LpeAB active efflux system, further confirmed by the reserpine/resazurin microtiter assay. In conclusion, this study has provided additional susceptibility data for environmental Legionella pneumophila isolates from Northern Italy demonstrating, in general, low MICs values for the tested antimicrobials, although one strain tested was shown to possess the LpeAB resistance determinant, indicating that future surveillance studies are warranted.

The Effectiveness of 0.6% Povidone Iodine Eye Drops in Reducing the Conjunctival Bacterial Load and Needle Contamination in Patients Undergoing Anti-VEGF Intravitreal Injection: A Prospective, Randomized Study

The study purpose was to assess the efficacy of a preservative-free 0.6% povidone iodine eye drops as perioperative prophylactic treatment for reducing conjunctival bacterial load and the rate of needle contamination in patients undergoing intravitreal anti-vascular endothelial growth factor injection. Enrolled patients were randomized to either the study group (0.6% povidone iodine, three day-prophylactic treatment before the injection) or to the control group (placebo, three day-prophylactic treatment). Conjunctival swabs were obtained before and after the prophylactic treatment in both groups. Intravitreal injections were performed in a sterile fashion. The injection needle and a control needle were collected for microbiological culture. Data from 254 and 253 eyes in the study group and control group, respectively, were analyzed. Bacterial growth from conjunctival swab cultures was significantly lower after 0.6% povidone iodine prophylaxis compared to baseline and to placebo prophylaxis (p < 0.001), showing an 82% eradication rate in the study group. No injection needle showed bacterial contamination in the study group, whereas six needles were culture-positive in the control group (p = 0.015). No serious ocular and non-ocular adverse events were recorded. The 0.6% povidone iodine solution proved an effective treatment in reducing conjunctival bacterial load and risk of needle contamination.

In vitro bactericidal activity of 0.6% povidone-iodine eye drops formulation

PURPOSE

To evaluate the bactericidal activity of a diluted povidone-iodine formulation (0.6%) in comparison with the most used 5% povidone-iodine solution ophthalmic preparation.

METHODS

In vitro bactericidal activity comparison between 0.6% povidone-iodine versus 5% povidone-iodine formulations, against these bacteria: Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12228, linezolid-resistant Staphylococcus epidermidis α99 strain, a clinical isolate, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922.

RESULTS

About 0.6% povidone-iodine formulation was demonstrated to be faster than 5% povidone-iodine preparation in killing Gram-positive as well as Gram-negative bacteria. Against a linezolid-resistant methicillin-resistant Staphylococcus epidermidis strain, 0.6% povidone-iodine formulation showed the best antiseptic efficacy requirement of 3-log₁₀ reduction in bacterial load, if compared with the 5% povidone-iodine formulation.

CONCLUSION

Our investigation has demonstrated that the more diluted 0.6% preparation was more rapidly bactericidal than the 5% povidone-iodine formulation, most probably due to the fact that dilution from 5% to 0.6% increases the amount of free iodine. While our finding must be confirmed by in vivo clinical studies, this fact constitutes an intriguing news for what concerns the use of povidone-iodine eye drops in the ocular surface treatment before intravitreal injections as well as ophthalmic surgery.

Resistance to linezolid in Staphylococcus spp. clinical isolates associated with ribosomal binding site modifications: novel mutation in domain V of 23S rRNA

Linezolid is the main representative of the oxazolidinones, introduced in 2000 in clinical practice to treat severe Gram-positive infections. This compound inhibits protein synthesis by binding to the peptidyl transferase centre of the 50S bacterial ribosomal subunit. The aim of this study was to characterize 12 clinical strains of linezolid-resistant Staphylococcus spp. isolated in Northern Italy. All isolates of Staphylococcus spp. studied showed a multi-antibiotic resistance phenotype. In particular, all isolates showed the presence of the mecA gene associated with SSCmec types IVa, V or I. Mutations in domain V of 23S rRNA were shown to be the most prevalent mechanism of linezolid resistance: among these a new C2551T mutation was found in S. aureus, whilst the G2576T mutation was shown to be the most prevalent overall. Moreover, three S. epidermidis isolates were shown to have linezolid resistance associated only with alterations in both L3 and L4 ribosomal proteins. No strain was shown to harbor the previously described cfr gene. These results have shown how the clinical use of linezolid in Northern Italy has resulted in the selection of multiple antibiotic-resistant clinical isolates of Staphylococcus spp., with linezolid resistance in these strains being associated with mutations in 23S rRNA or ribosomal proteins L3 and L4.

Chemical Profile, Antioxidant and Antibacterial Activities of Achillea moschata Wulfen, an Endemic Species from the Alps

Aerial parts of Achillea moschata Wulfen (Asteraceae) growing wild in the Italian Rhaetian Alps were investigated to describe, for the first time, their phenolic content, as well as to characterize the essential oil. Inspection of the metabolic profile combining HPLC-DAD and ESI-MS/MS data showed that the methanol extract contained glycosylated flavonoids with luteolin and apigenin as the main aglycones. Among them, the major compound was 7-O-glucosyl apigenin. Caffeoyl derivates were other phenolics identified. The essential oil obtained by steam distillation and investigated by GC/FID and GC/MS showed camphor, 1,8-cineole, and bornylacetate as the main constituents. The antioxidant capacity of three different extracts with increasing polarity and of the essential oil was evaluated by employing ABTS·+ and DPPH· radical scavenging assays. The methanolic extract was the only significantly effective sample against both synthetic radicals. All samples were also tested against Gram-positive (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa) bacterial species using the disk diffusion assay. The non-polar extracts (dichloromethane and petroleum ether) and the essential oil possessed a broad spectrum of antimicrobial activity expressed according to inhibition zone diameter (8–24 mm).

Gender and age-dependent etiology of community-acquired urinary tract infections

Urinary tract infections (UTIs) are among the most frequent community-acquired infections worldwide. Escherichia coli is the most common UTI pathogen although underlying host factors such as patients' age and gender may influence prevalence of causative agents. In this study, 61 273 consecutive urine samples received over a 22-month period from outpatients clinics of an urban area of north Italy underwent microbiological culture with subsequent bacterial identification and antimicrobial susceptibility testing of positive samples. A total of 13 820 uropathogens were isolated and their prevalence analyzed according to patient's gender and age group. Overall Escherichia coli accounted for 67.6% of all isolates, followed by Klebsiella pneumoniae (8.8%), Enterococcus faecalis (6.3%), Proteus mirabilis (5.2%), and Pseudomonas aeruginosa (2.5%). Data stratification according to both age and gender showed E. coli isolation rates to be lower in both males aged ≥60 years (52.2%), E. faecalis and P. aeruginosa being more prevalent in this group (11.6% and 7.8%, resp.), as well as in those aged ≤14 years (51.3%) in whom P. mirabilis prevalence was found to be as high as 21.2%. Streptococcus agalactiae overall prevalence was found to be 2.3% although it was shown to occur most frequently in women aged between 15 and 59 years (4.1%). Susceptibility of E. coli to oral antimicrobial agents was demonstrated to be as follows: fosfomycin (72.9%), trimethoprim/sulfamethoxazole (72.9%), ciprofloxacin (76.8%), ampicillin (48.0%), and amoxicillin/clavulanate (77.5%). In conclusion, both patients' age and gender are significant factors in determining UTIs etiology; they can increase accuracy in defining the causative uropathogen as well as providing useful guidance to empiric treatment.

Prevalence of plasmid-mediated quinolone resistance genes in uropathogenic Escherichia coli isolated in a teaching hospital of northern Italy

A retrospective study was conducted to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in uropathogenic Escherichia coli isolated from inpatients and outpatients in a teaching hospital of northern Italy. The presence of qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA was evaluated in 76 and 72 nalidixic acid-resistant E. coli, isolated in 2004 and 2006, respectively. Positivity for the aac(6')-Ib-cr gene was demonstrated in 3 of 76 (3.9%) and 8 of 72 (11%) isolates, respectively; no other PMQR determinant was found. All aac(6')-Ib-cr-positive strains also showed two point mutations in the gyrA and parC genes. Most aac(6')-Ib-cr-positive isolates demonstrated the contemporary presence of bla(CTX-M-15), bla(OXA-1/30), and bla(TEM-1) genes and 4/11 harbored a class 1 integron with a dfrA17-aadA5 gene cassette arrangement. Interestingly, all aac(6')-Ib-cr-positive isolates belonged to B2 phylogenetic group, O25b antigen type, multi locus sequence type 131, and to a cluster of approximately 70% similarity level by pulsed-field gel electrophoresis (PFGE). These findings suggest the circulation of the previously described intercontinentally spreading E. coli O25:H4-ST131 clone in our geographical area since 2004. Hybridization studies of the PFGE profiles showed the aac(6')-Ib-cr gene to be associated with different molecular weight bands (40-350 kb) and interestingly aac(6')-Ib-cr chromosomal integration was demonstrated in one strain by I-Ceu I method. This represents the first report to investigate the presence and diffusion of PMQR determinants in northern Italy and to describe aac(6')-Ib-cr chromosomal integration in E. coli.

Frequency and clinical significance of human beta-herpesviruses in cervical samples from Italian women

Human papillomaviruses (HPVs) are necessary, but not sufficient, for the development of cervical cancer (CC). Human beta-herpesviruses (beta-HHVs) have been suggested as possible cofactors in the oncogenesis of CC. In this cross-sectional study, the prevalence and possible association of cytomegalovirus (CMV), HHV-6 and -7 with HPV presence was investigated by quantitative real-time PCR assays in cervical samples obtained from 208 italian women. The two most common high-risk HPV types found were 31 and 16. Overall, the positive rates for CMV, HHV-6 and HHV-7 were 66%, 25%, and 6%, respectively. In particular, the prevalence of CMV was found to be extremely high irrespective of either the cytological category or HPV positivity. The prevalence of HHV-6 DNA was significantly higher in high-grade squamous intraepithelial lesions (HSIL) respect to normal women (P < 0.017); by contrast, the prevalence HHV-7 DNA was generally low and not associated with SIL. Copresence of CMV and HHV-6 DNA was found to be significantly higher in patients with SIL respect to normal women (P < 0.05). No correlation was demonstrated between the viral load of all three beta-HHVs and the different cytological stages or with the HPV presence. A few patients with severe disease however showed very high viral loads which for HHV-6 may be indicative of viral integration. In conclusion, this study suggests that CMV and HHV-7 alone are probably not implicated in the oncogenesis of CC whilst HHV-6 alone or together with CMV may contribute to the development of CC.

Prevalence of the internalization-associated gene prtF1 in a bacterial population of Streptococcus pyogenes isolated from children with acute pharyngotonsillitis before and after antibiotic therapy

The prevalence of the internalization-associated prtF1 gene was studied in 837 isolates of Streptococcus pyogenes obtained from 713 pediatric patients presenting with acute pharyngotonsillitis before and after antibiotic therapy. Its association with macrolide resistance and with bacteriological treatment failure was determined. The bacterial population isolated from baseline pharyngeal swabs showed an overall prtF1 positivity rate of 33%. A higher prtF1 positivity was found among erythromycin-resistant strains (45%) showing, however, marked differences between the inducible (iMLS), constitutive (cMLS), and efflux pump (M) resistance phenotypes. The prevalence was statistically higher (p < 0.001) in strains belonging to iMLS (84%) and cMLS (67%) phenotypes as compared to the M phenotype (15%). Interestingly, the prevalence of the prtF1 gene was significantly lower (p = 0.04) in strains belonging to M resistance phenotype as compared to erythromycin-susceptible strains (28%). Failed bacterial eradication was demonstrated in 124 patients. The prtF1 positivity rate remained unchanged in strains isolated before and after therapy in patients treated with macrolides (9/54). On the other hand, the positivity rate for the prtF1 gene was significantly higher (p = 0.015) in strains isolated after therapy with beta-lactams (21/70) as compared to baseline isolates (6/70), indicating a differential selection imposed on the organism by these agents. Finally, a high overall eradication rate (88%) of prtF1-positive isolates, belonging to both the erythromycin-susceptible and -resistant phenotypes, was demonstrated following macrolide treatment.

Bacteriological and clinical efficacy of various antibiotics used in the treatment of streptococcal pharyngitis in Italy. An epidemiological study

A total of 123 community paediatricians and 23 microbiology laboratories studied the clinical and bacteriological efficacy of treatment of group A streptococcal pharyngitis in Italy. Of 1065 patients, from whom Streptococcus pyogenes was isolated, 723 returned to follow up and of these 138 (19%) still had a positive throat culture. The erythromycin resistance (ER) rate was 23.7% with resistance phenotype distribution of: 31.7% constitutive (CR), 26.6% inducible (IR) and 41.7% efflux pump (M) resistance phenotype. All strains were susceptible to the beta-lactam agents tested. CR strains were highly resistant to all 14, 15 and 16 membered macrolides with the exception of rokitamycin which showed activity against 37.8% of isolates. All phenotype M and some IR isolates were susceptible to clindamycin, rokitamycin, josamycin and spiramycin; clarithromycin was active against a small percentage of strains belonging to the IR and M phenotype. Bacterial eradication was found in 85.5, 78.7 and 75.8% of the penicillin, macrolide and cephalosporin treated groups. Genotyping of strains showed that 8.7% of the 19% of cases classified as 'failed bacterial eradication' were due to recolonization with a different isolate, observed exclusively among beta-lactams treated patients. Clinical cure was achieved in a high percentage of cases, irrespective of the antibiotic prescribed, with the best clinical efficacy being found following therapy with amoxycillin and clarithromycin (90.9%).

High incidence of erythromycin-resistant Streptococcus pyogenes in Monza (North Italy) in untreated children with symptoms of acute pharyngo-tonsillitis: an epidemiological and molecular study

A retrospective analysis of susceptibility data available for Group A streptococcal isolates collected between January 1990 and January 1996 at the Hospital Microbiology Laboratory of Monza (North Italy), showed a sharp rise in the erythromycin resistance rates during the last 3 years. Streptococcus pyogenes resistant to erythromycin accounted for approximately 1% of strains isolated between 1990 and 1992; the percentage then rose from 5% in 1993 to almost 39% in 1995. In January 1996, the resistance rates peaked to 81%. A prospective controlled study performed between March and May of 1996 to determine the percentage of erythromycin-resistant Group A streptococci isolated in Monza from untreated children with acute pharyngo-tonsillitis, gave further confirmation of a high rate of erythromycin resistance (47%) in this area. Molecular characterization by T-serotyping and pulse-field gel electrophoresis analysis of 25 erythromycin-resistant Group A streptococcal isolates, showed a relatively high degree of heterogeneity among these strains, demonstrating that the increased resistance is not caused by the spread of a single clone.

Molecular typing of erythromycin-resistant streptococcus pyogenes strains with the M phenotype isolated in Italy

To assess the spread of the new M phenotype, various erythromycin-resistant Streptococcus pyogenes strains from three Italian cities (Verona, Monza, Florence) were characterised. Each strain was analysed for the presence of genes ermAM and mefA, for the ability to accumulate radioactive erythromycin in the absence of sodium arsenate, for the protein T serological type, and for the DNA macrorestriction profile identified by means of pulsed-field gel electrophoresis. In a number of strains, the presence of the inducible ermAM gene was demonstrated; all these strains were negative in the efflux-pump detection assay, did not possess the mefA gene, and had similar restriction profiles. The strains with the efflux mechanism and mefA gene belonged to different serotypes. Of these, only one serotype, T4, was isolated in all three cities. The restriction profile analysis with SmaI and SfiI revealed a very close correlation between strains with the same serotype.

Bactericidal kinetics of an in vitro infection model of once-daily ceftriaxone plus amikacin against gram-positive and gram-negative bacteria

The in vitro efficacy of ceftriaxone plus amikacin combination against gram-positive and gram-negative bacteria, clinically isolated from patients affected by pneumonia in intensive care units, was compared to that of the 2 drugs used alone. The study was performed using a dynamic model in which the human kinetics of the drugs after intramuscular administration was simulated. The antibacterial activity was tested by determining the bacterial cell count (CFU/ml). Killing curves came out from plotting the log CFU/ml versus time. In the same way, ceftriaxone and amikacin concentrations were assayed by HPLC and fluorescence polarization immunoassay, respectively. The results show that ceftriaxone plus amikacin combination exert a high killing activity against all tested strains. The two antibiotics alone initially have a good killing activity but this is followed by bacterial regrowth for all tested isolates. This data supports the results of several clinical studies which have shown a good therapeutic efficacy of ceftriaxone plus amikacin combination in the treatment of severe infections caused by organisms intermediately sensitive to these drugs.

Serum levels of flurithromycin ethylsuccinate in healthy volunteers

The serum levels of flurithromycin ethylsuccinate achieved 30 min after a single oral dose of 375 mg were found to be equal or above the minimal inhibitory concentrations for sensitive strains, when administered to 12 healthy volunteers. The serum half-life was found to be approximately 4 h.

Rufloxacin once daily versus ofloxacin twice daily for treatment of complicated cystitis and upper urinary tract infections. Italian Multicentre UTI Rufloxacin Group

The efficacy and safety of rufloxacin once daily was compared with that of ofloxacin b.i.d. for therapy of complicated cystitis and upper urinary tract infections. Eighty-three patients were randomly assigned to receive rufloxacin as a loading dose of 400 mg on the first day, followed by 200 mg s.i.d., and 80 received ofloxacin 300 mg b.i.d. Both agents were administered orally for a median duration of eight days. Bacterial elimination rates after treatment were 90% for rufloxacin and 81% for ofloxacin. Half of the treatment failures occurred in patients with infections caused by uropathogens that became either less sensitive or resistant to the quinolones being studied. At a two-week follow-up, recurrences had not occurred in any of the rufloxacin patients and had occurred in 17% of the ofloxacin patients. Minor adverse reactions were reported by 12 and 13 patients, respectively. Rufloxacin once daily is as effective as ofloxacin b.i.d. for the treatment of complicated cystitis and upper urinary tract infections.

Pharmacokinetics of rufloxacin in healthy volunteers after repeated oral doses

Rufloxacin is a new broad-spectrum fluoroquinolone antibacterial agent. The pharmacokinetics and safety of rufloxacin were evaluated after repeated oral administration to healthy volunteers. The drug was administered once a day for 6 consecutive days following two different dose schedules. The first group of 11 subjects was given a loading dose of 300 mg on the first day and 150 mg on the subsequent 5 days. The second group of 12 subjects was given a loading dose of 400 mg and 200 mg for 5 days. Serum levels and urine concentrations of rufloxacin were determined by microbiological assay. A simultaneous fit of all data points for each subject was done according to a one-compartment open model. The drug was rapidly absorbed (absorption half-life 17 +/- 6 min in the 300 + 150 mg and 11 +/- 5 min in the 400 + 200 mg dose regimen group) and reached maximal serum concentrations (2.77 +/- 0.24 and 3.62 +/- 0.35 micrograms/ml) 4.2 +/- 0.4 and 4.0 +/- 0.9 h after the first administration. Steady-state serum concentrations (3.19 +/- 0.31 and 4.06 +/- 0.33 micrograms/ml) were reached in 3.7 +/- 0.7 and 4.5 +/- 0.4 days. Elimination half-lives were 29.5 +/- 2.4 and 36.0 +/- 2.8 h. Apparent volumes of distribution were 111 +/- 8 and 136 +/- 16 liters and apparent plasma clearances were 46 +/- 5 and 44 +/- 4 ml/min. Renal clearances were 18 +/- 3 and 17 +/- 2 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro activity of a new quinolone, rufloxacin, against nosocomial isolates

The in vitro activity of rufloxacin (MF 934), a new broad-spectrum fluoroquinolone, was tested against 1,032 gram-positive and gram-negative clinical isolates and compared to that of five other compounds of this class. All quinolones except for ciprofloxacin had limited activity against group A and B streptococci and pneumococci (MIC 90% of 4-64 mg/l) and no activity against enterococci. Most species of the enterobacteriaceae and staphylococci were found to be sensitive to rufloxacin (MIC 90% of 0.5-8 and 2-8 mg/l). Like the other quinolones except for ciprofloxacin, rufloxacin was not active against Pseudomonas aeruginosa. The antibacterial activity of rufloxacin was affected only minimally by an increase in the bacterial inoculum or by alterations in the pH of the medium. In spite of the relatively higher MICs of rufloxacin compared to those of the other quinolones, its favorable pharmacokinetic properties may account for its good clinical efficacy.

HTLVI antibodies in multiple sclerosis and other neurological diseases

The sera and the CSFs from 157 Multiple Sclerosis (MS) patients and 43 other neurological diseases (OND) cases have been evaluated for the presence of HTLVI antibodies. A commercial passive agglutination assay (PPA), an indirect fluorescence assay (IFA), and a Western Immunoblotting (WIB) performed in our laboratories have been employed. No OND samples showed HTLVI antibodies, while 14 sera and 1 CSF from MS patients resulted positive by PPA and 4 sera were positive with the IFA. When tested with WIB 6 MS sera showed a reactivity against one or more HTLVI proteins. Our results lead us to affirm that in a small number of MS patients, when sensitive tests are employed, it is possible to observe an antibody response toward proteins that share one or more epitope with HTLVI antigens.

Inhibition of murine leukemia (WEHI-3B and L1210) proliferation by cholera toxin B subunit

Cholera holotoxin produces both stimulation and inhibition of the growth of different cell populations. These opposite effects were both attributed to the enzymatic activity of the subunit A that activates adenylate cyclase, increasing the intracellular level of cAMP. We observed that the B subunit of cholera toxin produced by itself an inhibition of the 'in vitro' growth of two murine leukemia cell lines (L1210 limphoid leukemia and WEHI-3B myelomonocytic leukemia). The sensitivity of WEHI-3B cells towards cholera toxin was about 5000-times higher than that of the L1210 cells, whereas the two leukemias showed an identical sensitivity to the B subunit (IC50 = 5.10(-10) M for L1210 and 10(-10) M for WEHI-3B). The inhibition produced by the B subunit was neutralized by GM1 and in a minor degree by type II gangliosides. The two leukemias showed a remarkable difference in their gangliosides contents (L1210 cells contained GM1 (80.6%) and GM2 (19.4%), while WEHI-3B cells contained GM1 (28.2%), Fuc-GM1 (44.9%) and a band (26.9%) with a chromatographic mobility between GD1a and GD1b). The inhibition could be explained by a competitive mechanism between the B subunit and some autocrine factor binding GM1-containing receptors. Our data strengthen the suggestion to consider gangliosides as very important pleiotropic biomodulators.

Antibacterial activity of tigemonam dicholate (SQ 30836) and interaction with beta-lactamases of gram-negative bacteria

SQ 30836 is an orally absorbed salt of tigemonam, a new monobactam similar to aztreonam in structure and microbiologic properties. When assayed against 400 clinical isolates, tigemonam's activity was similar to that of aztreonam and carumonam. It was highly effective against Enterobacteriaceae but showed poor activity against gram-positive organisms. It inhibited 90% of Escherichia coli, Klebsiella, Shigella, Yersinia, Proteus, Providencia, and Morganella strains at 0.5 micrograms/mL or less, and all Salmonella and Hafnia strains at 1 micrograms/mL or less. Citrobacter, Enterobacter, and Serratia strains were less susceptible (minimum inhibitory concentrations [MIC30] of 2, 32, and 8 micrograms/mL respectively). The activity of the new compound against Enterobacteriaceae is comparable with and often higher than that of third-generation cephalosporins and oral comparison compounds. In contrast to aztreonam, tigemonam had minimal activity against Pseudomonas sp and glucose nonfermenting gram-negative bacteria. Data suggest that poor penetration through the outer membranes of Pseudomonas sp may be responsible for this failure. Tigemonam was stable to hydrolysis by plasmid-mediated and chromosomal beta-lactamases. It was more stable than aztreonam to hydrolysis by the Kl enzyme of Klebsiella and by the Proteus vulgaris beta-lactamase. Also, measurement of the IC50 (concentration of inhibitor able to reduce the activity of the enzyme by 59%) showed that tigemonam has less affinity than aztreonam for class I cephalosporinases. However, only levels of beta-lactamase, not hydrolysis rates or affinity, correlated to MICs of the two monobactams for the resistant Enterobacter and Citrobacter strains.

Carumonam's in-vitro activity against gram-negative bacteria and its stability to their beta-lactamases

The in vitro activity of the novel monobactam carumonam (RO17-2301) was evaluated on 311 gram-negative clinical isolates in comparison to aztreonam, cefotaxime, ceftazidime, cefotetan and ceftriaxone. Carumonam showed an antibacterial potency equal to or higher than any other reference compound; in particular it was the most effective against Proteus indole positive and Klebsiella sp. Its antipseudomonal activity was comparable to that of ceftazidime and it showed, together with aztreonam, the highest activity against the Citrobacter, Enterobacter and Escherichia coli isolates. The minimal inhibitory concentrations performed on permeability altered organisms indicated that carumonam has a penetration rate comparable to aztreonam and higher than cefotetan and ceftriaxone. Carumonam demonstrated excellent stability to chromosomal and plasmid-mediated beta-lactamases and that correlated with its antibacterial activity against the producing strains and inoculum size effect.