Achromobacter xylosoxidans respiratory tract infection in cystic fibrosis patients.

The aims of this study were to evaluate the frequency of Achromobacter xylosoxidans infection in a cohort of cystic fibrosis patients, to investigate antimicrobial sensitivity, to establish possible clonal likeness among strains, and to address the clinical impact of this infection or colonization on the general outcome of these patients. The study was undertaken between January 2004 and December 2008 on 300 patients receiving care at the Regional Cystic Fibrosis Center of the Naples University "Federico II". Sputum samples were checked for bacterial identification. For DNA fingerprinting, pulsed-field gel electrophoresis (PFGE) was carried out. Fifty-three patients (17.6%) had at least one positive culture for A. xylosoxidans; of these, 6/53 (11.3%) patients were defined as chronically infected and all were co-colonized by Pseudomonas aeruginosa. Of the patients, 18.8% persistently carried multidrug-resistant isolates. Macrorestriction analysis showed the presence of seven major clusters. DNA fingerprinting also showed a genetic relationship among strains isolated from the same patients at different times. The results of DNA fingerprinting indicate evidence of bacterial clonal likeness among the enrolled infected patients. We found no significant differences in the forced expiratory volume in 1 s (FEV(1)) and body mass index (BMI) when comparing the case group of A. xylosoxidans chronically infected patients with the control group of P. aeruginosa chronically infected patients.

Proton pump inhibitors as a risk factor for paediatric Clostridium difficile infection.

BACKGROUND: Proton pump inhibitors (PPIs) and H(2) receptor antagonists (H(2)RAs) may play an important role on the onset of Clostridium difficile-associated disease (CDAD) in adults. The impact of Clostridium difficile on children treated with gastric acid-suppressing agents remains unknown. AIM: To investigate the relationship between CDAD and exposure to acid suppressive therapy in hospitalized paediatric patients. METHODS: We reviewed the medical records of children, with a diagnosis of protracted diarrhoea and abdominal pain, whose stool was analysed for C. difficile toxins. We identified 68 patients with CDAD. For each patient, we randomly selected one control subjects with stool analysis negative for C. difficile. Comorbid illnesses, previous hospitalizations, antibiotics, corticosteroids, immunosuppressants and gastric acid suppressing exposures were recorded. RESULTS: The use of PPI was significantly higher in C. difficile positive group compared with C. difficile negative group [odds ratio (OR): = 4.5; 95% confidence interval (CI) = 1.4-14.4]. We also found a trend for the use of H(2)RAs in patients infected by C. difficile compared with C. difficile negative comparison group (OR: = 3.8; 95% CI = 0.7-18.9). CONCLUSIONS: Children exposed to PPIs therapy seem to be at higher risk for the development of Clostridium difficile-associated disease.

Prenatal screening for congenital toxoplasmosis in Campania: preliminary report on activities and results.

By 1997, an open cohort of 1,652 live newborn of 1,637 mothers with gestational toxoplasmosis had been recruited in the Campania region to monitor the burden of congenital toxoplasmosis (CT). Of the 1,556 mother-child pairs that completed the follow up, 92 definite cases were detected, yielding a 5.9% (4.8-7.1 95% CI) transmission rate. The onset was patent for 43% of patients and sensorineural complications were shown for a further 15% of subclinical onset patients later than two years of age. The overall prevalence of toxoplasmosis during gestation was 2.46 of 1,000 deliveries, while the prevalence of definite CT was 1.38 of 10,000 live newborns. However, there is still room for intervention, as only 23% of the maternal diagnoses were proven through seroconversion, 63 of the late-gestation seroconverters remained untreated, and six probable CT diagnoses were made following referrals due to patent sequelae and born during the study period. There was a positive secular trend on the rates of infant referral and definite CT diagnosis, according to the live birth rate (Chi2 for trend < 0.001). Extension of this surveillance system across the country could help to define a future strategy for prevention.

Typing of vancomycin-resistant Enterococcus faecium strains in a cohort of patients in an Italian intensive care Unit.

BACKGROUND: Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infections. The increase of vancomycin-resistant Enterococcus faecium (VR-Efm) in an intensive care unit (ICU) of an Italian university hospital from 2003 through 2004, led us to evaluate the phenotypic and genetic features of these strains. The prevalence of different bacterial species in this ICU is described. The antibiotic resistance profiles of VR-Efm strains, their van-genotype and pulsed-field gel electrophoresis (PFGE) profiles were also analyzed. MATERIALS AND METHODS: From January 2003 to December 2004, VR-Efm strains were collected from several biological samples. Bacteria were identified using standard biochemical reactions and automated systems. Antibiotic susceptibility was evaluated by disk diffusion and microdilution methods. Resistance to glycopeptides was confirmed by the E test. Vancomycin-resistant genotypes (vanA, vanB) were identified by PCR. Strains were typed by PFGE. RESULTS: Fifty E. faecium strains were isolated from a total of 700 patients. Of these, 26 were vancomycin-resistant and were isolated from 26 different patients. We also found one strain with resistance to linezolid. The vanA genotype was identified in 20/26 strains and vanB in the remaining strains. A major pulsed-field cluster ("A") was identified. In this cluster, 14 strains were identified (A1-A14) and 25 out of 26 VR-Efm belonged to it. Only one strain showed a different pattern (strain type "B"). All isolates with the vanA genotype belonged to cluster "A", therefore five out of six isolates with the vanB genotype belonged to cluster A. The only strain with type B pattern was the vanB genotype. CONCLUSIONS: Isolation of VR-Efm was very frequent (52%) in our cohort of patients and the vanA genotype was the most frequent (77%). We found 25 out of 26 VR-E. faecium strains to be epidemiologically related by PFGE (cluster A). Strains with distinct genotypes shared closely related PFGE profiles. The occurrence of one major cluster among patients of a single unit indicated intra-facility VRE transmission.

Delayed maturation of IgG avidity in congenital toxoplasmosis.

The aim of this comparative study was to investigate the clinical usefulness of the measurement of Toxoplasma gondii IgG avidity in the postnatal diagnosis of congenital toxoplasmosis. IgG avidity values in serum samples from infants with congenital infection were compared with those in samples from uninfected infants, all born to mothers with toxoplasmosis acquired during gestation. This analysis revealed that IgG avidity values soon after birth reflected maternal values in the large majority of the samples. Low or borderline IgG avidity values were systematically found in the cohort of congenitally infected subjects. After birth, IgG avidity values slowly increased over time for up to 2 years in congenitally infected subjects. On the contrary, IgG avidity values in the uninfected infants remained stable over time. The presence of low IgG avidity in a newborn can be considered a marker of maternal seroconversion in the second or third trimester of gestation and, as a consequence, an indicator of risk for congenital toxoplasmosis. An IgG avidity assay can be easily carried out with antibodies eluted from dried blood spots (Guthrie cards), providing an opportunity to retrospectively evaluate the risk of congenital infection in special clinical circumstances, for example when suspicion of congenital infection arises during late infancy.

Performance characteristics of an enzyme-linked immunosorbent assay for determining salivary immunoglobulin G response to Helicobacter pylori.

We evaluated the salivary immunoglobulin G (IgG) immune response to Helicobacter pylori in 70 subjects by enzyme-linked immunosorbent assay (ELISA). Subjects with a positive H. pylori culture showed significantly higher titers of antibodies than subjects with no detectable H. pylori: the overall sensitivity and specificity of the test were 84 and 90%, respectively. The detection of salivary anti-H. pylori IgG antibodies may be considered as an alternative to serum IgG detection for ease of sample collection or when blood samples are not available in screening of patients with dyspepsia.

A second European collaborative study on polymerase chain reaction for Toxoplasma gondii, involving 15 teams.

In order to investigate the accuracy and practicability of the polymerase chain reaction (PCR) in the antenatal diagnosis of congenital toxoplasmosis, a collaborative study involving 15 European laboratories was performed under the auspices of the Biomed 2 Programme of the European Community. Each team received 12 aliquots (four negative, eight positive) of 'artificial samples' made of amniotic fluid spiked with tachyzoites of the RH strain of Toxoplasma gondii. Each team performed its own PCR protocol (all were different). Nine of the 15 laboratories were able to detect a single parasite, but two of the 15 found all samples negative. Four of the 15 laboratories found one or more control samples to be falsely positive. This study highlights the lack of homogeneity between PCR protocols and performance and underlines the need for an external quality assurance scheme which could provide 'reference' samples that could be used by any laboratory wanting to establish and maintain an accurate diagnostic test based on PCR.

Detection of IgG and IgA against the mycobacterial antigen A60 in patients with extrapulmonary tuberculosis.

BACKGROUND: Diagnosis of extrapulmonary tuberculosis is often difficult to establish using standard methods. Serological techniques based on detection of antibodies against mycobacterial antigen A60 have shown good sensitivity and specificity in pulmonary tuberculosis. The present study was undertaken to define the diagnostic accuracy of testing for IgG and IgA against A60 in extrapulmonary tuberculosis. METHODS: One hundred and ninety eight subjects were studied: 42 patients with extrapulmonary tuberculosis confirmed by microbiology and/or histology, 24 subjects with healed pulmonary or extrapulmonary tuberculosis, 44 patients with a defined non-tuberculous disease, and 88 healthy volunteers (44 PPD negative and 44 PPD positive). Detection of IgG and IgA against A60 antigen was carried out by enzyme-linked immunosorbent assay. Cut off values were determined by receiver operating characteristic curves. RESULTS: Sensitivity of the IgG test was 73.8% in extrapulmonary tuberculosis, while the specificity was 96.1%. The IgA test showed a sensitivity of 69.0% with a specificity of 93.6%. Combination of the IgG and IgA tests showed a sensitivity of 80.9% and a specificity of 92.3%. Patients with extrapulmonary tuberculosis showed significantly higher titres of both IgG and IgA against A60 than other groups. CONCLUSIONS: Anti-A60 IgG or IgA tests are characterised by good sensitivity and specificity. The combined use of both tests allows an increase in diagnostic accuracy of extrapulmonary tuberculosis.

Evaluation of IgA-mediated humoral immune response against the mycobacterial antigen P-90 in diagnosis of pulmonary tuberculosis.

BACKGROUND: Serologic methods for diagnosis of tuberculosis have been widely investigated owing to their low cost and rapid technical execution. Sensitivity and specificity of different tests have been reported to be largely variable. STUDY OBJECTIVES: To evaluate the IgA-mediated humoral immune response against the mycobacterial antigen P-90 as a tool for diagnosis of pulmonary tuberculosis. PARTICIPANTS: Eighty-eight patients with microbiologically confirmed diagnosis of pulmonary tuberculosis (32 with positive sputum smears and 56 with negative sputum smears), 28 patients with a definite nontuberculous lung disease, 12 subjects with healed tuberculosis, and 47 healthy volunteers (24 purified protein derivative negative and 23 positive). MEASUREMENTS AND RESULTS: Detection of anti-P-90 IgA was performed by enzyme-immunoassay. At a cutoff of 0.221 optical density, determined by a receiver operating characteristic curve, the overall sensitivity and specificity of the test were 70.4% and 91.9%, respectively. Patients with active tuberculosis showed significantly higher titers of anti-P-90 IgA compared with other groups (p < 0.05). CONCLUSIONS: The evaluation of IgA-mediated humoral immune response against the antigen P-90 might constitute a useful tool for presumptive diagnosis of pulmonary tuberculosis.

Detection of IgA against the mycobacterial antigen A60 in serum and saliva in patients with active pulmonary tuberculosis: preliminary results.

Humoral immune response against the mycobacterial antigen A60 was evaluated in 38 subjects: 13 healthy volunteers (Group I), 10 patients with a defined acute or chronic non tuberculous lung disease (Group II), 15 patients suffering from pulmonary tuberculosis (Group III). Saliva IgA in samples diluted in various concentrations (1:10, 1:30, 1:50) and serum IgG and IgA levels were measured by ELISA. Positive values of IgG were found in sera of 0/13 subjects from Group I, 1/10 from Group II, 12/15 from Group III; searching for IgA in serum was positive in 1/13 subjects from Group I, 2/10 from Group II, 11/15 from Group III, 1:30 dilution of saliva led to positive results in 0/13 subjects from Group I, 0/10 from Group II and 10/15 from Group III. The measurement of anti-A60 IgA levels in both saliva and serum might be a useful complement to serology based on detection of anti-A60 IgG in blood samples.

Cirrhosis negatively affects the efficiency of serologic diagnosis of Helicobacter pylori infection.

In cirrhosis, Helicobacter pylori infection may be implicated, together with portal hypertension, bile reflux and alcohol abuse, in damage to gastric mucosa. Aim of this study was to define the influence of non-alcoholic liver disease on the incidence of Helicobacter pylori infection and on the diagnostic accuracy of specific serology. Enrolled in the study were 232 individuals, 105 also had cirrhosis. Infection by Helicobacter pylori, diagnosed by a positive concordance of quick urease test and histology, was detected in 97 (48 with cirrhosis) out of 184 patients. Severe gastritis was more frequent in patients with Helicobacter pylori infection than in patients without. Cirrhosis did not significantly affect the prevalence of Helicobacter pylori infection or the histological features of gastritis. Specific anti-Helicobacter pylori IgG and IgA assay (Bio-Rad GAP test) was used for serological diagnosis. Anti-Helicobacter pylori IgG showed a high sensitivity (85% in cirrhotics, 89% in non-cirrhotics) and low specificity being more evident in cirrhotics (38% vs 56% non-cirrhotics). Serum specific IgA showed low sensitivity (approximately 25% in both groups) and specificity of 79% in cirrhotics vs 84% in non-cirrhotics. In conclusion, non-alcoholic cirrhosis does not affect the incidence of Helicobacter pylori infection and the histological features of chronic gastritis but does decrease diagnostic efficiency of serological tests for Helicobacter pylori.

IgA immune response against the mycobacterial antigen A60 in patients with active pulmonary tuberculosis.

Searching for IgG and IgM against the mycobacterial antigen A60 has been recognized as a potential diagnostic tool for pulmonary tuberculosis. The role of detection of anti-A60 IgA in improving diagnostic accuracy of serology is not well known. In this study we measured with ELISA serum levels of both anti-A60 IgG and IgA in 216 subjects. 88 healthy volunteers (44 PPD- and 44 PPD+), 44 patients suffering from nontuberculous lung disease and 15 subjects with healed pulmonary tuberculosis constituted the control population; 69 patients with active pulmonary tuberculosis (35 cavitary forms, 26 productive forms and 8 miliary forms) were examined. The sensitivity of IgG test was 73.9% in pulmonary tuberculosis (77.1% in cavitary forms, 65.4% in productive forms, 87.5% in miliary forms); the specificity of the test was 95.9%. For the IgA test we observed a sensitivity of 72.5% (74.3 in cavitary forms, 69.2% in productive forms, 75.0 in miliary forms) and a specificity of 93.9%. Combination of the two tests increased the sensitivity to 84.0% (+10.1% compared to IgG test, +11.5% compared to IgA test); the specificity decreased to 92.5% (-3.4% vs. IgG test; -1.4 vs. IgA test). In conclusion, the combined use of evaluation of anti-A60 IgG and IgA increases the accuracy of serological diagnosis of pulmonary tuberculosis.

[Clinico-epidemiological considerations of 30 cases of pulmonitis and pleuropulmonitis in childhood]. / Considerazioni clinico-epidemiologiche su 30 casi di polmonite e pleuropolmonite in età pediatrica.

The authors studied 30 children affected with pneumonia or pleuropneumonia. They point out some clinical and epidemiological features pertinent to the pathology examined.

[The correlation between psittacosis-ornithosis and the immune status in childhood: apropos 5 cases]. / Correlazione fra psittacosi-ornitosi ed assetto immunitario in età infantile: a proposito di 5 casi.

The authors studied 5 children affected with a pneumopathy by Chlamydia psittaci. They discuss the effects of a transitory immunodeficiency relative to NK cells in predisposing little patients to the infective disease.

Molecular cloning of Chlamydia trachomatis 26K protein expressed in Escherichia coli.

Molecular genetics appears to be the most promising approach to understanding the biology and pathology of Chlamydia. This report focuses on the cloning and the protein expression of a DNA fragment from Chlamydia trachomatis DK20 chromosome. Results of hybridization experiments suggest that this sequence is specifically present within chlamydial DNA. The coding capacity of this DNA fragment is supported by the expression of a 26,000 m.w. peptide, in an Escherichia coli maxicell system.

Relative validity of multiple telephone versus face-to-face 24-hour dietary recalls.

The relative validity of multiple telephone 24-hour dietary recalls was evaluated in a feasibility study within the framework of a large prospective investigation on the cause of chronic disease in women. Forty-nine women were interviewed four times both face-to-face and by telephone. Comparison of the total number of calories and intake of protein, carbohydrate, total and saturated fats, cholesterol, fiber, sodium, potassium, calcium, vitamin A, and vitamin C as estimated by multiple face-to-face and telephone interviews revealed an acceptable relative validity for the telephone procedure. Analysis of the position variation in the distribution (percent agreement) comparing the two procedures showed that a change in the distribution of none or one quintile occurs in more than 70% of individuals for all nutrients but vitamin C (69.4%), cholesterol (61.2%), and vitamin A (51.4%). Correlation coefficient analysis showed similar results. Adjustment for nutrient densities did not affect the overall results. Multiple 24-hour telephone dietary recalls appear to be a valid alternative to face-to-face interviews in population studies.

ELISA method for evaluation of anti-A60 IgG in patients with pulmonary and extrapulmonary tuberculosis.

Several studies on the IgG mediated humoral immune response against the mycobacterial antigen A60 are available in the literature. However extensive variability in observed responses has been reported. In the present study we measured by ELISA the titers of IgG antibodies against A60 in 50 tuberculin negative healthy subjects, (Group I); 44 tuberculin positive healthy subjects, (Group II); 13 patients with healed Tuberculosis (Group III); 22 patients with a defined acute or chronic Non Tuberculous Pulmonary Pathology (Group IV); 42 patients suffering from sputum positive Active Pulmonary Tuberculosis, (Group V); 15 patients with sputum negative Active Pulmonary Tuberculosis (Group VI) and 16 patients with Active Extrapulmonary Tuberculosis (Group VII). The assay was performed at the time of recruitment into the study, corresponding for patients of Groups IV to VII to the day of hospital admission; in patients from Groups III to VII the assay was repeated two weeks later. The cut-off point was defined as mean +2SD of values found in Groups I-IV and was 0.372 (expressed in Optical Density). By using this cut-off, the test on first blood samples was positive in 1/50 subjects from Group I, 1/44 from Group II, 0/13 from Group III, 3/22 patients from Group IV, 35/42 from Group V, 9/15 from Group VI, 9/16 from Group VII. On second blood samples, kept 9-12 days after starting anti-TB chemotherapy in Groups V, VI and VII, the test resulted positive in 0/13 patients from Group III, 3/22 from Group IV, 39/42 from Group V, 13/15 from Group VI and 14/16 from Group VII.

Laboratory survey of Chlamydia trachomatis ocular infections.

The authors used immunofluorescence and immunoperoxidase tests to study a group of 101 patients with acute or chronic conjunctivitis, etiologically unrelated to conventional bacterial pathogens, and a control group of 30 healthy adults. Positive titers of IgG in serum and of IgA in lacrimal secretions against Chlamydia, detected by IPA, correlated with the identification of microorganisms by direct immunofluorescence. The use of both tests allows a precise evaluation of the stage of the infection and of its evolutive pattern.

A serological study of mycobacterial infections in AIDS and HIV-1 positive patients.

The Authors have tested the new Tb-Elisa method to detect specific antibodies, raised against A60 major mycobacterial antigen complex, in patients of groups II, III and IV of CDC classification suffering from acquired immunodeficiency and in HIV-1 negative control subjects. The test results support laboratory diagnosis of acute phase and reactivation of mycobacterial infection.

[An indirect hemagglutination study of total IgE and complement fractions C3c and C4 in patients with hepatic hydatidosis and undergoing therapy]. / Studio dell'emoagglutinazione indiretta, delle IgE totali e delle frazioni del complemento C3c e C4 in pazienti affetti da idatidosi epatica e sottoposti a terapia.

The trend of antibodies tested with indirect hemagglutination, of total IgE and complement fraction was examined in patients with liver hydatid disease, treated with surgery and benzoimidazoles.