H-ferritin and CD68(+) /H-ferritin(+) monocytes/macrophages are increased in the skin of adult-onset Still's disease patients and correlate with the multi-visceral involvement of the disease.

Adult-onset Still's disease (AOSD) patients may show an evanescent salmon-pink erythema appearing during febrile attacks and reducing without fever. Some patients may experience this eruption for many weeks. During AOSD, exceptionally high serum levels of ferritin may be observed; it is an iron storage protein composed of 24 subunits, heavy (H) subunits and light (L) subunits. The ferritin enriched in L subunits (L-ferritin) and the ferritin enriched in H subunits (H-ferritin) may be observed in different tissues. In this work, we aimed to investigate the skin expression of both H-and L-ferritin and the number of macrophages expressing these molecules from AOSD patients with persistent cutaneous lesions. We observed an increased expression of H-ferritin in the skin, associated with an infiltrate in the biopsies obtained from persistent cutaneous lesions of AOSD patients. Furthermore, a positive correlation between H-ferritin skin levels as well as the number of CD68(+) /H-ferritin(+) cells and the multi-visceral involvement of the disease was observed. Our data showed an increased expression of H-ferritin in the skin of AOSD patients, associated with a strong infiltrate of CD68(+) /H-ferritin(+) cells. Furthermore, a correlation between the levels of H-ferritin as well as of the number of CD68(+) /H-ferritin(+) cells and the multi-visceral involvement of the disease was observed.

In vitro activity of Aloe vera inner gel against microorganisms grown in planktonic and sessile phases.

The failure of traditional antimicrobial treatments is becoming a worldwide problem. The use of Aloe vera is of particular interest for its role as curative agent and its efficacy in complementary therapies for a variety of illnesses. This study evaluated the antimicrobial activity of A. vera inner gel against a panel of microorganisms, Gram-positive and -negative bacteria, and Candida albicans. In addition to A. vera inner gel being used in the treatment of peptic ulcers, in dermatological treatments, and wound healing, it was also tested on the sessile phase of clinical Helicobacter pylori strains (including multi-drug-resistant strains) and on planktonic and sessile phase of Staphylococcus aureus/Pseudomonas aeruginosa clinical isolates from venous leg ulcers.A. vera inner gel expresses its prevalent activity against Gram-negative bacteria and C. albicans in respect to Gram-positive bacteria. The results of the A. vera antibiofilm activity showed a decrease of the produced biomass in a concentration-dependent-way, in each analyzed microorganism. The data obtained show that A. vera inner gel has both an antimicrobial and antibiofilm activity suggesting its potential use for the treatment of microbial infections, in particular for H. pylori gastric infection, especially in case of multi-drug-resistance, as well as for an effective wound dressing.

In vitro activity of Aloe vera inner gel against Helicobacter pylori strains.

UNLABELLED: Aloe barbadensis Miller (Aloe vera) is a herbal remedy widely used for a variety of illnesses; A. vera leaf extracts have been promoted for detoxification, cure constipation, help flush out toxins and wastes from the body, promote digestion and are used in the treatment of peptic ulcer for cytoprotective action. The aim of this study was to evaluate the antibacterial activity of A. vera inner gel against both susceptible and resistant Helicobacter pylori strains isolated in Abruzzo region, Italy. The inner gel of leaves of a 5-year-old plant of A. vera was extracted, homogenized and tested from 800 to 1.56 mg ml(-1) against 14 clinical strains and one reference strain of H. pylori using the broth microdilution methodology. Furthermore, the sample of A. vera was investigated for the chemical fingerprint of anthraquinones. The inhibitory concentrations of A. vera inner gel were similar to the bactericidal ones, with values ranging from 6.25 to 800 mg ml(-1) . Fifty per cent of the detected strains, independently of their susceptibility profile, were inhibited in their growth at 100 mg ml(-1) . Aloe vera inner gel expresses antibacterial properties against H. pylori and, therefore, in combination with antibiotics, could represent a novel strategy for the treatment of the infection of H. pylori, especially in cases of multiresistance. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates that the Aloe vera inner gel expresses antibacterial properties against both susceptible and resistant Helicobacter pylori strains. These findings may impact on the antimicrobial resistance phenomenon of H. pylori, proposing the A. vera inner gel as a novel effective natural agent for combination with antibiotics for the treatment of H. pylori gastric infection.

Doom or Deliciousness: Challenges and Opportunities for Visualization in the Age of Generative Models.

Generative text-to-image models (as exemplified by DALL-E, MidJourney, and Stable Diffusion) have recently made enormous technological leaps, demonstrating impressive results in many graphical domains-from logo design to digital painting to photographic composition. However, the quality of these results has led to existential crises in some fields of art, leading to questions about the role of human agency in the production of meaning in a graphical context. Such issues are central to visualization, and while these generative models have yet to be widely applied in visualization, it seems only a matter of time until their integration is manifest. Seeking to circumvent similar ponderous dilemmas, we attempt to understand the roles that generative models might play across visualization. We do so by constructing a framework that characterizes what these technologies offer at various stages of the visualization workflow, augmented and analyzed through semi-structured interviews with 21 experts from related domains. Through this work, we map the space of opportunities and risks that might arise in this intersection, identifying doomsday prophecies and delicious low-hanging fruits that are ripe for research.

Helicobacter pylori biofilm: a protective environment for bacterial recombination.

AIMS: The aim of this work was to investigate the interaction between two Helicobacter pylori strains in promoting genetic transfer, when grown in the biofilm mode. METHODS AND RESULTS: Biofilms produced by H. pylori 9/10 (A), H. pylori 15/4 (B) and their mixture (C) were studied for biomass production and cell viability. The genetic heterogeneity of 45 clones, coming from mature biofilm of co-cultured H. pylori strains was studied by both RAPD and cagA (EPIYA motifs)/vacA virulence genes analysis. Helicobacter pylori A, B and C developed a well-structured biofilm without significant differences in viability. No significant differences were recorded between A and B biomass measurement, whereas C biofilm expressed a significant (P < 0.001) higher adhesive capability when compared with A and B biofilms. C-clones DNA-fingerprintings showed an high genetic heterogeneity (mean similarity value = 0.528). The 60% of C-clones displayed vacA allelic combination s1i1m1m2 associated with cagA EPIYA motif pattern P1P2P3P3P3. CONCLUSIONS: Biofilms developed by multiple H. pylori strains are more complex than those associated with single strains. Such condition might promote the genetic exchange favouring the generation of more virulent strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The 'biofilm niche' represents a successful strategy and a suitable environment for promoting bacterial population persistence by recombination events.

Effect of 2-hydroxyethyl methacrylate on Streptococcus spp. biofilms.

AIMS: The effect of different concentrations of 2-hydroxyethyl methacrylate (HEMA) was evaluated on biofilm formation and preformed biofilm of Streptococcus mitis, Streptococcus mutans and Streptococcus oralis, alone or combined to each other. METHODS AND RESULTS: Twofold serial dilution of HEMA ranged from 12 to 0·75 mmol l(-1) was added to Streptococcal broth cultures and mature biofilms in 96-well-microtitre plates to evaluate bacterial biomass and cell viability. HEMA affected the Streptococcal population in a strain-specific way producing few significant effects. A reduction on biofilm formation and a detachment of preformed biofilm was recorded in Strep. mitis ATCC 6249, whereas in mixed cultures, the monomer expressed a general aggregative effect on mature biofilms. A reduction in cell viability was also recorded in an HEMA-concentration-dependent way in each experimental condition studied. CONCLUSIONS: These results suggest that the HEMA prevalent effects are both the reduction of bacterial adhesion to a polystyrene surface and the increase in dead cells also characterized by an aggregative status. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding the potential effect of HEMA, released from resin-based materials, on oral bacteria may furnish information for surveillance of the risk reduction in secondary caries via hindering biofilm generation.

[Road traffic crashes, alcohol, meals, sleep and work hours: a case-crossover study at the Emergency Room of Udine, Italy]. / Incidenti stradali, alcol, pasti, sonno e ore di lavoro: uno stu- dio di case-crossover presso il Pronto Soccorso di Udine.

In case-crossover studies, useful for assessing the effect of acute transient exposures, each case acts as his/her own control, therefore, interpersonal confounding is controlled for by study. We used such design for studying the effect of the acute consumption of alcohol and meals, and of sleep and work hours on the risk of road traffic crashes. Subjects, enrolled at the Emergency Room (ER) of Udine from 12/3/2007 to 11/3/2008, were a sample of the drivers who arrived alive at the ER after a crash. They were interviewed by trained interviewers, who systematically covered predefined shifts, using a semi-structured questionnaire. The questionnaire collected information on the subjects, vehicles, and crashes, and contained a hourly diary of the exposure to driving, sleeping, working in the 48 hours before the crash and to alcohol and meals 24 hours before the crash. The statistical analysis was based on the matched pair interval approach. The exposures in the hours immediately before the crash (case window) were compared with those in previous hours (control window). Different window durations were chosen for different exposures. The relative risk (RR) of having a crash and 95% confidence intervals (95% CI) were estimated with conditional logistic regression, adjusting for potential confounders such as day of the week and time. We observed a statistically significant two-fold increase in the RR for drivers who had consumed alcohol (even small amounts) and a four-fold increase for those who had worked > 12 ore. The RR was increased by 10 times for drivers who had been awake for at least 16 hours. Meals were not associated with the risk of crash; the findings regarding sleep amount were controversial. In conclusion, the study confirms an increased risk of road crashes after consuming alcohol, even for amounts below the legal limit, and suggests that extended work hours and prolonged wakefulness may increase the risk of crashes.

Characterization of an Helicobacter pylori environmental strain.

AIMS: To investigate the main genotypic virulence markers and the phenotypic features of an environmental Helicobacter pylori strain, named MDC1. METHODS AND RESULTS: The H. pylori MDC1 genotypic status was evaluated by PCR amplification. The mosaicism in vacA alleles was expressed by the s1m1 allelic combination, as found in strains which are strong vacuolating cytotoxin producers; the number of cagA variable EPIYA motifs displayed P1P2P3P3 pattern and the iceA1 was recorded between the iceA allelic types and the babA2 gene found in strains causing more severe disease. The biofilm formation was evaluated on a polystyrene surface in static conditions by scanning electron microscopy and confocal scanning laser microscopy. Helicobacter pylori MDC1 displayed a dense mature biofilm with cells in a coccoid morphology persistent in time in which the expression of the luxS gene, related to the quorum-sensing signalling, was always detected. CONCLUSIONS: Helicobacter pylori MDC1 strain had the main virulence markers closely related to gastric pathogenesis and displayed a well-structured biofilm which allowed this bacterium to be more protected in the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: The persistence of the environmental virulent H. pylori strain in a clustered state suggests a long-term survival of this bacterial community outside of the host, enabling the bacterial transmission with important clinical repercussions.

Ceramide accumulation precedes caspase-dependent apoptosis in CHP-100 neuroepithelioma cells exposed to the protein phosphatase inhibitor okadaic acid.

The protein phosphatase inhibitor okadaic acid (OA) dose-dependently induced apoptosis in CHP-100 neuroepithelioma cells when administered for 24 h at concentrations ranging from 10 - 100 nM. Apoptosis was largely, albeit not completely, dependent on cystein protease (caspase) activation. CPP32 processing and poly(ADP-ribose) polymerase (PARP) cleavage started to be observed only at 20 nM OA; moreover, the caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethylketone (Z-VAD.fmk) (100 microM) had negligible effect on apoptosis induced by 10 nM OA, but rescued from death an increasing cell fraction as OA concentration was raised from 20 - 100 nM. Cell treatment for 24 h with OA induced ceramide accumulation; the phenomenon started to be evident at 20 nM OA and reached its maximum at 50 - 100 nM OA. In cells exposed to 50 nM OA, ceramide was already elevated by 5 h; at this time, however, PARP cleavage and apoptosis were not yet observed. Z-VAD.fmk (100 microM) had no effect on ceramide elevation induced by 50 nM OA within 5 h, but markedly reduced ceramide accumulation as the incubation was prolonged to 24 h. The latter phenomenon was accompanied by elevation of glucosylceramide levels, thus suggesting that a caspase-dependent reduction of glucosylceramide synthesis might contribute to late ceramide accumulation. Short-chain ceramide (30 microM) induced apoptosis in CHP-100 cells and its effect was additive with that evoked by OA (10 - 20 nM). These results suggest that ceramide generation might be an important mechanism through which sustained protein phosphatase inhibition induces caspase activation and apoptosis in CHP-100 cells.

[Neonatal conjunctivitis in a hospital at Gran Buenos Aires. Last 5 years up-date]. / Conjuntivitis neonatal en un hospital del Gran Buenos Aires. Situación de los últimos 5 años.

Neonatal conjunctivitis is one of the most important consultation reasons in the first days of life. Causes may be chemical or infectious. Neonatal conjunctivitis study for common microorganisms and Chlamydia trachomatis is being performed at Posadas Hospital since 1995, in a progressive form. The objective of this study was to know the epidemiological situation in the last five years (1999-2003), and to describe the variations detected between two periods, 1995-1998, and 1999-2003. It was observed no change about C. trachomatis prevalence (8%), during all the time in the population studied. With regard to common microorganisms it was showed a decrease in the second period (36.6%) with respect to the first (52.4%). Likely, the causes may be due to changes about sample collection conditions, or to epidemiological variations. The most frequent microorganisms found were: Staphylococcus aureus 69 (27.6%), Streptococcus pneumoniae 68 (27.2%), and Haemophilus influenzae 64 (25.6%). We consider important to evaluate the kind of ocular secretions at the first consultation, which can lead to a symptomatic treatment that will be corroborated or not, according to microbiological results.

[Streptococcus agalactiae in pregnant women. Prevalence at the Posadas Hospital]. / Streptococcus agalactiae en embarazadas. Prevalencia en el Hospital Nacional Alejandro Posadas.

Streptococcus agalactiae (Lancefield group B Streptococcus), is the most frequent microorganism involved in neonatal infections through the mother-fetus vertical transmission. It is also responsible for infections in pregnant women, and adults with underlying diseases. The objective of this work was to know the S. agalactiae carrier prevalence in pregnant women who attended to Posadas Hospital, and to study the susceptibility pattern of the isolates to penicillin, erythromycin and clindamycin. From 1203 pregnant women studied, S. agalactiae was recovered in 113, which means a prevalence of 9.39%. Antimicrobial susceptibility was tested to 87 isolates. All of them were susceptible to penicillin, and only 2 isolates were resistant to erythromycin and clindamycin (constitutive MLS mechanism). We emphasize the importance of knowing these last resistance, in the case of beta-lactam antibiotics allergic women.

Liposome-induced exfoliation of graphite to few-layer graphene dispersion with antibacterial activity.

Few-layer graphene aqueous dispersions are obtained by exploiting liposomes as effective exfoliating agents for graphite. Raman measurements evidence the presence of non-oxidized double layer graphene as well as amphiphilic phospholipid molecules organized in bilayers in the samples. TEM analyses confirmed that the obtained homogeneous graphene nanosheets are embedded in the liposomal bilayer. The as-prepared graphene aqueous dispersion is stable for days and demonstrates significant antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains, with a reduction in the growth of S. aureus and E. coli as high as 60 and 78%, respectively.

Chemokine receptor CXCR2 regulates the functional properties of AMPA-type glutamate receptor GluR1 in HEK cells.

Experiments were conducted in both HEK cells and cerebellar neurons to investigate whether CXC chemokine receptor 2 (CXCR2) is functionally coupled to GluR1. The co-expression of CXCR2 with GluR1 in HEK cells increased (i) the GluR1 "apparent" affinity for the transmitter; (ii) the GluR1 channel open probability; and (iii) GluR1 binding site cooperativity upon CXCR2 stimulation with CXC chemokine ligand 2 (CXCL2). The affinity of C-terminal-deleted GluR1 for glutamate (Glu) remained stable instead. Furthermore, CXCL2 increased the binding site cooperativity of AMPA receptors in rat cerebellar granule cells; and the amplitude of spontaneous excitatory postsynaptic current (sEPSCs) in Purkinje neurons (PNs). Our findings indicate that the coupling of CXCR2 with GluR1 may modulate glutamatergic synaptic transmission.

Potentiation of okadaic acid-induced ceramide elevation but not apoptosis by inhibition of glucosylceramide synthase in human neuroepithelioma cells.

Caspase-dependent apoptosis induced by okadaic acid (OA) in CHP-100 neuroepithelioma cells has previously been shown to associate with a rapid and sustained elevation in intracellular ceramide concentration. We now report that treatment of CHP-100 cells with OA also evoked a rapid elevation in glucosylceramide levels that was maintained at steady state as cells underwent apoptosis; moreover, as observed for ceramide, OA-induced glucosylceramide accumulation was not blocked by fumonisin B1. Remarkably, when cell death was prevented by caspase inhibition, glucosylceramide accumulation was potentiated and ceramide elevation reduced, thus suggesting that, during apoptosis completion, accumulation of ceramide was partly driven by impairment of its glucosylation through a caspase-dependent mechanism. We studied whether ceramide glucosylation provided a mechanism for negative modulation of OA-induced apoptosis. We observed that the blocking of glucosylceramide synthesis markedly potentiated OA-induced ceramide elevation, but neither accelerated apoptosis onset nor potentiated the apoptotic response. These results indicate that modulation of ceramide glucosylation does not affect the apoptotic response to okadaic acid and suggest that caution must be exercised concerning the possibility that ceramide plays a key role in apoptosis induction.

Evidence for an oral-faecal transmission of Helicobacter pylori infection in an experimental murine model.

An experimental murine model was used to evaluate the possible animal-to-animal transmission of Helicobacter pylori and the mechanism involved. Twenty-four Balb/C mice were infected with H. pylori type I strain culture and kept with 24 noninoculated mice to evaluate the possible transmission of the microorganism. Twelve inoculated mice were housed with 12 noninoculated mice in a grated cage (supporting an oral-oral transmission); the remaining inoculated and noninoculated mice were housed in another cage without grating on the floor (supporting a faecal-oral transmission). The bacterial colonization was assessed by culture and immunohistochemistry. The systemic antibody response to H. pylori and the histopathological changes were evaluated; controls were examined at 2, 4, 8, 12 weeks after the start of the experiment. Faecal samples were also collected from each mouse on the day before sacrifice, to assess the presence of H. pylori by culture and by immunohistochemistry. In the gastric mucosa of inoculated mice, histopathological changes were recorded at each control time and H. pylori was detected both by immunohistochemistry and by a systemic antibody response; the microorganism was also cultured at 2, 4, 8 weeks postinoculation. H. pylori was detected in noninoculated mice, housed in the cage without grating, using an immunoperoxidase technique at 2, 4, 8 weeks after starting the experiment, and these positive values were supported by histopathological changes, and, in one case, at 8 weeks, also by the serum immune response. No colonies of H. pylori were detected by culturing faecal samples from either noninoculated or inoculated mice. The results obtained in this study seem to support an oral-faecal route as the mode of transmission of H. pylori infection in this animal model.

Recovery of Helicobacter pylori ATCC43504 from a viable but not culturable state: regrowth or resuscitation?

Studies were conducted following the formation and characterization of the coccoid morphology of Helicobacter pylori. H. pylori ATCC43504 was incubated in brucella broth plus 2% fetal calf serum at three different temperatures: 37 degrees C, room temperature and 4 degrees C in a microaerophilic environment, and readings were taken at 2, 7, 15, 30 and 45 days. At control times, the total and the viable count, viability tests with tetrazolium salts, and ultrastructural studies were carried out. On solid media, H. pylori became nonculturable after 7 days of incubation at room temperature and 4 degrees C, and after 15 days of incubation at 37 degrees C. At these times of incubation, after subculturing in liquid medium under the same conditions, the growth of H. pylori was detected until the 15th day from cultures incubated at 4 degrees C and until the 30th day from cultures stored at 37 degrees C, and at room temperature. Ultrastructural studies showed a gradual reduction of integrity of bacterial cells that remained stable at 30 and 45 days of incubation: 30% of whole cells of bacteria incubated at 37 degrees C and room temperature and 50% in bacteria incubated at 4 degrees C. The viability of the VNC (viable nonculturable) state was assessed by studying the reduction of tetrazolium salts INT (p-iodonitrophenyl tetrazolium violet) and CTC (cyanoditolyl tetrazolium chloride) to their respective formazans and this was linked to the cellular respiration. At 45 days of incubation, when bacterial regrowth was not observed in solid or in liquid medium, different resuscitation methods were applied to evaluate a possible resuscitation of VNC H. pylori. No significant growth on solid medium was observed.

Effects of 2 patterns of prehospital care on the outcome of patients with severe head injury.

HYPOTHESIS: A pattern of prehospital care combining advanced life support, physician staffing, and helicopter transport improves the outcome of patients with severe brain injuries, compared with combined expanded basic life support, nurse staffing, and ground transport. DESIGN: Inception cohort from the data set of a population-based, prospective study on major trauma. SETTING: Prehospital and hospital trauma systems of an Italian region. PATIENTS: All patients with major trauma (Injury Severity Score, >or=16) and severe head injury (Abbreviated Injury Scale score for the head, >or=4) rescued alive from March 1, 1998, to February 28, 1999, who received either form of care. Patients with self-inflicted injuries were excluded. The 184 patients who met the entry criteria were divided equally between care groups. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Mortality at 30 days and Glasgow Outcome Scale score of survivors. RESULTS: After verifying the comparability of the cohorts, no survival or disability benefit could be demonstrated (95% confidence interval [CI] of the odds ratio for mortality [helicopter/ambulance] [95% CI 1], 0.72 to 2.67; 95% CI of the difference in Glasgow Outcome Scale score medians between helicopter and ambulance groups [95% CI 2], 0.0 to 0.0). Similar results were derived from analyses restricted to the subgroups identified by low (

The effect of oxygen on the growth and cell morphology of Helicobacter pylori.

The in vitro effect of progressive oxygen decrease on the growth and morphology of Helicobacter pylori was studied. H. pylori ATCC 43,504 was used for the experiments. The strain inoculated in Brucella broth plus fetal calf serum was incubated under a controlled atmosphere with oxygen concentration from 5 to 0%. CFU ml-1 and bacterial morphology were detected at the time of spreading and at 24 h, 72 h, 7 days and 14 days. A detailed ultrastructural investigation of the bacterial cells, grown in different experimental conditions, was performed by scanning electron microscopy. Oxygen deprivation produced a rapid reduction of CFU ml-1. In particular, a significant reduction of viable bacteria was recorded at 72 h of incubation in the presence of 1% oxygen and anaerobiosis, and 0 CFU ml-1 was found after 7 days of incubation at the above mentioned oxygen concentrations. The coccoid phenotype was already prevalent after 24 h of incubation with a progressive tendency to aggregate in clusters. These clusters were progressively larger, depending on the reduction of oxygen concentration, since the aggregation phenomenon can be the expression of a hypothesized mechanism of protection among bacterial cells.

Inhibition of Helicobacter pylori by garlic extract (Allium sativum).

The antibacterial effect of aqueous garlic extract (AGE) was investigated against Helicobacter pylori. Sixteen clinical isolates and three reference strains of H. pylori were studied. Two different varieties of garlic were used. The concentration of AGE required to inhibit the bacterial growth was between 2-5 mg ml-1. The concentration, for both AGE types, to inhibit 90% (MIC90) of isolates was 5 mg ml-1. The minimum bactericidal concentration (MBC) was usually equal to, or two-fold higher than, minimum inhibitory concentration (MIC). Heat treatment of extracts reduced the inhibitory or bactericidal activity against H. pylori; the boiled garlic extract showed a loss of efficacy from two- to four-fold the values of MIC and the MBC obtained with fresh AGE. The antibacterial activity of garlic was also studied after combination with a proton pump-inhibitor (omeprazole) in a ratio of 250:1. A synergistic effect was found in 47% of strains studied; an antagonistic effect was not observed.

Incidence of Chlamydia trachomatis and other potential pathogens in neonatal conjunctivitis.

OBJECTIVE: Ocular infection in neonatology is a permanent and important health problem. To improve primary attention, prevention, and control, the study of the potential bacterial etiology of all consecutive cases of conjunctivitis was incorporated as a regular procedure in primary care from July 1995 to December 1998. MATERIALS AND METHODS: Prof. A. Posadas Hospital (Great Buenos Aires) has an average of 4294 births per year. This report analyzes the results obtained in 332 infants (age range, 0-30 d) with conjunctivitis. Clinical conjunctivitis was diagnosed in inpatients and outpatients by the same specialized staff. Isolation and characterization of bacteria were done by conventional microbiologic methods, including specific search for Neisseria gonorrhoeae and Chlamydia trachomatis. Chlamydia trachomatis was studied by antigen immunodetection and polymerase chain reaction, and genotyped by restriction fragment length polymorphism. RESULTS: Conjunctivitis had an incidence (cases per 1000 live births) of 39.6 in 1995, 25.3 in 1996, 15.4 in 1997, and 15.2 in 1998. Microbial growth was detected in 167 (50.3%) of 332 cases. Ocular C. trachomatis infection was detected in 26 cases (7.83%). Five of seven isolates in tissue cultures belonged to type E and two to type G. Bacteria from respiratory ecology were the main isolates: Haemophilus influenzae (16.9%), Streptococcus pneumoniae (12.3%), and Staphylococcus aureus (8.7%). Haemophilus influenzae isolates were not serotyped and 17.2% of them were b-lactamase producers. In 15 cases both H. influenzae and S. pneumoniae were isolated together. Of S. pneumoniae, 4.9% were oxacillin resistant. CONCLUSIONS: There has been a decline in the total number of cases of neonatal conjunctivitis, but the disease is still an important health problem. Chlamydia trachomatis also shows a decreasing profile with an incidence of (cases per 1000 live births) 4.39 in 1995, 1.85 in 1996, 1.01 in 1997, and 0.78 in 1998, and a tendency to show more incidence in spring-summer and significant accumulation of cases in babies between 7 and 9 days of age. Haemophilus influenzae alone (12.3%) or associated with S. pneumoniae (4.5%) appears as a prevalent potential bacterial pathogen. A significant accumulation of H. influenzae and S. pneumoniae cases occurs in winter. In 47.6% of cases, there was no bacterial growth. No significant seasonal differences in percentage of negative cultures or among the three-day age groups were detected. Neisseria gonorrhoeae was not found associated with ophthalmia neonatorum in this series.