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Biomedical subjects

A Bartoloni

Publications and source records attributed to A Bartoloni.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prevalence of epilepsy in rural Bolivia: a door-to-door survey.

OBJECTIVE: To carry out a door-to-door survey in rural areas of the Cordillera Province, Santa Cruz Department, Bolivia, to determine the prevalence of neurologic diseases (epilepsy, stroke, parkinsonism, and peripheral neuropathy) in a sample of approximately 10,000 inhabitants. METHODS: A team of nondoctor health workers administered a standard screening instrument for neurologic diseases-a slightly modified version of the World Health Organization protocol. All subjects found positive during the screening underwent a neurologic examination. RESULTS: On screening, the authors found 1,130 positive subjects, of whom 1,027 were then investigated by neurologists. On the basis of the definition proposed by the International League Against Epilepsy, we detected 124 epileptic patients (prevalence, 12.3/1,000), 112 of whom had active epilepsy (prevalence, 11.1/1,000) on the prevalence day (November 1, 1994). Peak age-specific prevalence occurred in the 15 to 24-year age group (20.4/1,000). Sex-specific prevalence was higher in women (13.1/1,000) than men (11.4/1,000). Eighty-nine patients (71.8%) underwent a standard EEG recording. Considering both EEG and clinical data, partial seizures were the most common type (53.2%) based on the classification of the International League Against Epilepsy. The mean age at onset was 20.7 years for partial seizures and 13.6 years for generalized seizures. Only 10.5% of patients had received specific treatment for more than 2 months of their life. CONCLUSION: This report on epilepsy prevalence in Bolivia confirms that epilepsy is a major health problem in rural areas of developing countries.

Adolescent↗
PubMed1999

Size determination of bacterial capsular oligosaccharides used to prepare conjugate vaccines.

We recently described the use of ion exchange chromatography for analysis and the industrial scale preparation of pools of oligosaccharides of intermediate chain length from polysaccharides of Haemophilus influenzae type b (Hib) and Neisseria meningitidis groups A and C. These negatively charged "sized" oligosaccharides are activated and conjugated to the carrier protein (CRM197) to prepare the corresponding glycoconjugate vaccines. Characterization and accurate determination of the degree of polymerization (DP) of the pool of oligosaccharides is essential for the consistent production of these conjugate vaccines. This paper describes the colorimetric assays used for determination of the average DP of the Hib and meningococcal oligosaccharides, and the qualification of these assays achieved by size characterization of the respective oligosaccharides by use of physicochemical methods, including liquid chromatography, mass spectrometry (ionspray) and NMR spectroscopy.

Bacterial Capsules↗
PubMed1999

HPLC does not differentiate Mycobacterium paratuberculosis from Mycobacterium avium.

HPLC, which is gaining its place as identification tool in mycobacteriology laboratories, has been proposed to distinguish Mycobacterium paratuberculosis from Mycobacterium avium. We had reported no significant difference between M. avium and M. paratuberculosis reference strain ATCC 19698. Because of the advantages offered by such a method, we enlarged our observations to include more isolates of M. paratuberculosis. Within the double cluster of peaks obtained by both M. avium and M. paratuberculosis, we could not find a consistent difference typical of M. paratuberculosis. Therefore, the present study confirmed that M. avium and M. paratuberculosis could not be distinguished by HPLC, raising doubts of a straightforward use of HPLC to identify M. paratuberculosis.

Animals↗
PubMed1999

Size fractionation of bacterial capsular polysaccharides for their use in conjugate vaccines.

We have developed a chromatographic method suitable for the fractionation of polysaccharides having a negatively charged group. The method permits the removal of all those polysaccharide fragments having a short sequence and which are likely unsuitable for conjugate vaccine construction. The selected polysaccharide fragments can be used to produce glycoconjugate vaccines containing a restricted saccharide polydispersion. We have applied this chromatographic method to three different antigens, Haemophilus influenzae type b and Neisseria meningitidis group A and group C polysaccharides. The method is easily adapted for manufacturing purposes.

Antigens, Bacterial↗
PubMed1999

Prevalence of antibodies against hepatitis A and E viruses among rural populations of the Chaco region, south-eastern Bolivia.

We conducted a cross-sectional study to determine the seroprevalence of antibodies against hepatitis A and hepatitis E viruses (HAV and HEV) in the population of two rural areas, Camiri and Villa Montes, of the Chaco region, south-eastern Bolivia. HAV antibodies were detected in 461 (94.1%) of 490 serum samples tested, not differing significantly between sexes and study areas. The HAV seropositivity rate (64.7%) was high even in the youngest age group (1-5 years). The prevalence of HEV was 7.3%, with no significant differences between sexes. The prevalence of HEV antibodies in the population of the Camiri area (10.4%) was significantly higher than in the Villa Montes area (4.4%), possibly due to the better quality of drinking water in the Villa Montes area. In the population </= 30 years of age, the HEV seropositivity rate (4.4%) was significantly lower than in the >/= 31 year-old group. This is consistent with findings in other countries. This is the first report of the prevalence of HEV infection in Bolivia.

Adolescent↗
PubMed1999

Mycobacterium tusciae sp. nov.

A new, slow-growing, scotochromogenic mycobacterium was isolated from a lymph node of an immunocompromised child and subsequently from tap water and from a respiratory specimen of a patient with chronic fibrosis. Alcohol-acid-fastness, lipid patterns and the G + C content clearly support the placement of this organism in the genus Mycobacterium. The isolates grew very slowly at temperatures ranging from 25 to 32 degrees C and showed activities of nitrate reductase, catalase, urease, arylsulfatase and Tween 80 hydrolysis. The organism was susceptible to all antimycobacterial drugs tested. The 16S rDNA sequence was unique and phylogenetic analysis placed the organism close to fast-growing species such as Mycobacterium farcinogenes, Mycobacterium komossense and Mycobacterium aichiense. These data support the conclusion that the isolates represent a new mycobacterial species, for which the name Mycobacterium tusciae sp. nov. is proposed. The type strain is strain FI-25796T; a culture of this strain has been deposited in the DSMZ as strain DSM 44338T.

Bacterial Typing Techniques↗
PubMed1999

[Antibodies against Trichinella spiralis in the rural population of the Province of Cordillera, Bolivia].

A seroepidemiological study was conducted to determine the prevalence of antibodies to Trichinella spiralis among rural residents of Cordillera province, Santa Cruz Department, Bolivia. Using the enzyme-linked immunosorbent assay (ELISA), 234 serum samples were examined, and antibodies were detected in seven of the samples (3%). The results document for the first time the presence of human infestation with Trichinella in Bolivia and suggest the need to strengthen trichinelosis surveillance in the municipal slaughterhouses, to prevent the clandestine slaughter of animals, and particularly to ensure that residents and meat producers in the area become aware of the dangers of this zoonosis.

Abattoirs↗
PubMed1999

Mansonella ozzardi infection in Bolivia: prevalence and clinical associations in the Chaco region.

A cross-sectional survey carried out in the Chaco region of Bolivia showed that 26% (77 of 296) and 0.7% (2 of 298) of the rural population of the Camiri and Villa Montes areas, respectively, harbored Mansonella ozzardi microfilariae (mf). No significant differences were observed between sexes. The lowest prevalence (9%) was in the 0-14-year-old age group, with no children <11 months of age infected. The prevalence increased sharply in the 25-34-year-old age group (32%), and continued increasing in the older age classes. Microfilaremia, ranging from 1 to 305 mf/20 microl of blood, was lowest in 0-14-year-old children (geometric mean concentration = 1.1 mf/20 microl), and increased with age (>100 mf/20 microl in people >44 years old). An expected increasing sensitivity with the blood volume examined was observed. No significant association between clinical symptoms (fever, skin rash, pruritus, headache, lymphedema, elephantiasis, and articular pain) and microfilaremia was observed.

Adolescent↗
PubMed1999

Multicenter randomized trial comparing meropenem (1.5 g daily) and imipenem/cilastatin (2 g daily) in the hospital treatment of community-acquired pneumonia.

An open, multicenter study with 144 patients, aged between 18 and 94 years, was performed to compare the efficacy and safety of meropenem with imipenem/cilastatin in the hospital treatment of community-acquired pneumonia. Patients were randomized to receive either intravenous meropenem (500 mg every 8 h) or intravenous imipenem/cilastatin (1,000 mg every 12 h). The primary end point was considered to be clinical efficacy and the secondary end points were bacteriological response and safety assessment. At the end of therapy, cure or improvement in signs and symptoms as a satisfactory clinical response was observed in 57 of 64 (89.1%) meropenem-treated patients and in 60 of 66 (90.9%) imipenem/cilastatin patients. The mean duration of treatment was 10 days for meropenem and 9.7 days for imipenem/cilastatin. In patients who were followed up for weeks 2-4, the response was satisfactory (100%) for both treatments. A satisfactory bacteriological response, defined as either presumed or confirmed eradication of all pathogens, was found in eight patients who had received meropenem and in 14 patients who had received imipenem/cilastatin. Response was considered satisfactory in 100% of the meropenem group and in 92.9% of the imipenem/cilastatin group and at follow-up, it was 100% for both treatments. Drug-related adverse events were reported in three (4.2%) meropenem-treated patients and in eight (11.0%) imipenem/cilastatin-treated patients. None of these events was classified as serious. The results of this study show that the clinical and bacteriological efficacy and tolerability of meropenem (500 mg every 8 h) are similar to that of imipenem/cilastatin (1,000 mg every 12 h) in the hospital treatment of community-acquired pneumonia.

Adolescent↗
PubMed1998

Bactericidal monoclonal antibodies that define unique meningococcal B polysaccharide epitopes that do not cross-react with human polysialic acid.

The poor immunogenicity of the Neisseria meningitidis group B polysaccharide capsule, a homopolymer of alpha(2-->8) sialic acid, has been attributed to immunologic tolerance induced by prenatal exposure to host polysialyated glycoproteins. Substitution of N-propionyl (N-Pr) for N-acetyl groups on the meningococcal B polysaccharide, and conjugation of the resulting polysaccharide to a protein carrier, have been reported to yield a conjugate vaccine that elicits protective Abs with minimal autoantibody activity. To characterize the protective epitopes on the derivatized polysaccharide, we isolated 30 anti-N-Pr meningococcal B polysaccharide mAbs. These Abs were heterogeneous with respect to complement-mediated bactericidal activity, fine antigenic specificity, and autoantibody activity as defined by binding to the neuroblastoma cell line, CHP-134, which expresses long-chain a(2-->8)-linked polysialic acid. Eighteen of the Abs could activate complement-mediated bacteriolysis. Seven of these 18 Abs cross-reacted with N-acetyl meningococcal B polysaccharide by ELISA and had strong autoantibody activity. Thus, N-Pr meningococcal B polysaccharide conjugate vaccine has the potential to elicit autoantibodies. However, 7 of the 18 bactericidal mAbs had no detectable autoantibody activity. These Abs may be useful for the identification of molecular mimetics capable of eliciting protective Abs specific to the bacteria, without the risk of evoking autoimmune disease.

Animals↗
PubMed1998

Patterns of antimicrobial use and antimicrobial resistance among healthy children in Bolivia.

OBJECTIVE: To determine the incidence of antimicrobial-resistant, nonpathogenic Escherichia coli among healthy children aged 6-72 months in Camiri town and a rural village, Javillo, in south-eastern Bolivia. METHOD: A community-based survey: stool samples were obtained from 296 healthy children selected by modified cluster sampling in Camiri and all 25 eligible children in Javillo. E. coli isolates were tested for antimicrobial susceptibility according to the standard disc diffusion method. By a questionnaire survey of 12 pharmacies and by using simulated patients, we investigated the antimicrobial availability and the usage patterns in Camiri town. RESULTS: In Camiri, over 90%, and in Javillo over 70% of children carried E. coli resistant to ampicillin, trimethoprim-sulphamethoxazole (TMP/SMX) or tetracycline. Overall, 63% of children carried E. coli with multiple resistance to ampicillin, TMP/SMX, tetracycline and chloramphenicol. In the simulated patients study, antimicrobials were dispensed inappropriately for 92% of adults and 40% of children with watery diarrhoea, and were under-prescribed for males with urethral discharge (67%) or females with fever and dysuria (58%). The dose and/or duration of antimicrobials dispensed was almost always too low. CONCLUSION: Our study showed a disturbingly high prevalence of carriage of nonpathogenic E. coli resistant to antimicrobials. The prevalence of resistance to ampicillin and TMP/SMX was higher than that previously reported in developing countries. The existence of a large reservoir of resistance genes in healthy individuals in developing countries represents a threat to the success of antimicrobial therapy throughout the world. Programmes to improve rational and effective drug use in developing countries are urgently needed.

Adult↗
PubMed1998

A neuroepidemiological survey in rural Bolivia: background and methods.

A door-to-door survey was carried out in rural areas of the Cordillera province, Santa Cruz Department, Bolivia. A cluster sample of 10,124 inhabitants was selected. The aim was to determine the prevalence of the most common neurological diseases (epilepsy, stroke, parkinsonism and peripheral neuropathy) in this population using a modification of the World Health Organization screening instrument. 1,130 subjects screened positive and were then investigated by neurologists. In this paper we describe the background and methods of the survey and the characteristics of the population.

Adolescent↗
PubMed1998

Seroprevalence of Toxocara canis-IgG antibodies in two rural Bolivian communities.

A survey on toxocara canis-IgG seroprevalence was carried out in two Bolivian communities (Mora and Zanja Honda) living in the Cordillera Province, Department of Santa Cruz. Two hundred and sixteen people, both males and females, 2 to 85 years old were sampled. Altogether, 73 people were positive (34%). The seroprevalence was 27% in Mora and 42% in Zanja Honda (p = 0.022). No statistical correlations were found with sex and age. High prevalences were also found for intestinal helminths (hookworms, Trichuris trichiura, Ascaris lumbricoides, Hymenolepis nana and Strongyloides stercoralis). Positive association between T. canis seropositivity and presence of T. trichiura and between T. trichiura and hookworms were found. T. canis egg prevalence in dog population was found consistently higher in Zanja Honda than in Mora (40% vs 27%).

Adolescent↗
PubMed1997

Cervical lymphadenitis due to an unusual mycobacterium.

A scotochromogenic acid-fast bacillus was isolated from a lymph node of a 2-year-old female. On the basis of conventional testing, the mycobacterium appeared to be Mycobacterium scrofulaceum. Its mycolic acid profile, however, was not identical to that of Mycobacterium scrofulaceum but was similar to that of Mycobacterium interjectum. Direct sequencing of the 16S rRNA gene revealed a unique nucleic acid sequence, suggesting that the isolate represents a previously undescribed pathogenic species.

Base Sequence↗
PubMed1997

Mycobacterium malmoense in Italy: the modern Norman invasion?

The isolation of Mycobacterium malmoense has for a long time been restricted to few countries of Northern Europe; reports from countries other than Sweden, Great Britain and Finland are rare and the first Italian case report has been published in 1995. Since 1988, however, fifteen strains of M. malmoense have been isolated in Italy, eleven of which in the last two years; of these, ten appeared clinically significant on the basis of medical records. The susceptibility of the strains and the role of high performance liquid chromatography of cell wall mycolic acids for a reliable identification are discussed.

Adult↗
PubMed1997

Serologic survey for antibodies to Borrelia burgdorferi in sheep, goats and dogs in Cordillera Province, Bolivia.

A serosurvey for antibodies to Borrelia burgdorferi using an enzyme-linked immunosorbent assay (ELISA) was conducted on sheep, goat and dog serum samples collected in Cordillera Province, Bolivia, in 1992 Sera from 98 sheep, 218 goats and 43 dogs were tested. The observed seroprevalence in sheep and dogs was 0.0%, whereas the seropositivity rate for goat serum samples was 5.0%. Upon analysing 10 positive sera by Western immunoblotting, five reacted against the specific protein antigens and all of them met the criteria for positivity on the basis of immunoglobulin G (IgG) bands, indicating that goats in Cordillera Province were exposed to B. burgdorferi. These findings, which are further proof of the existence of B. burgdorferi infection in Bolivia, indicate the serologic analysis of goats as a suitable tool for Lyme borreliosis surveillance.

Animals↗
PubMed1997

Characterization of mycobacterial isolates phylogenetically related to, but different from Mycobacterium simiae.

The use of high-performance liquid chromatography (HPLC) revealed four previously unreported profiles within a group of mycobacteria consisting of 14 clinical isolates. These mycobacteria, whose identification by conventional tests appeared problematic, mostly resembled Mycobacterium avium complex or Mycobacterium simiae. Genetic analysis revealed, within this group, six different nucleic acid sequences in a hypervariable 16S rRNA segment, but all the isolates appeared to be phylogenetically related to M. simiae. Six isolates representing the largest of groups defined by means of genetic sequencing turned out to belong to the newly described species Mycobacterium lentiflavum. Furthermore, three such clusters precisely coincided with three of those defined by HPLC, while the three remaining clusters shared almost identical HPLC profiles. All but one strain (which, although clearly not belonging to the M. avium complex, hybridized with specific commercial DNA probes) showed high-grade resistance to the majority of antimycobacterial drugs. Three of the isolates were clinically significant according to stringent criteria. Sophisticated techniques, like genetic sequencing or HPLC, by now seem indispensable for differentiating unusual and new mycobacteria from well-established ones.

Adult↗