Biomedical subjects

M A Telles

Publications and source records attributed to M A Telles.

12 recordsLinked to original sources

PubMed2005

Molecular typing of Mycobacterium bovis isolates from south-east Brazil by spoligotyping and RFLP.

The identification of 163 strains of Mycobacterium bovis by polymerase chain reaction (PCR) and microbiological tests was carried out on 252 tuberculous-like lesions (TLLs) collected from slaughtered cattle in south-east Brazil. This study compared the usefulness of three genotyping techniques, IS6110-restriction fragment length polymorphism (RFLP), polymorphic guanine-cytosine-rich sequence (PGRS)-RFLP and direct repeat (DR)-spoligotyping, as applied to M. bovis isolates. Based on IS6110-RFLP genotyping we selected a group of 23 isolates containing more than one IS6110 copy, along with 16 samples containing one IS6110 copy from different geographical areas, evenly distributed among dairy (eight) and beef cattle (eight). These selected isolates were analysed by PGRS-RFLP and DR-spoligotyping genotyping. Dairy cattle (17%) display a higher frequency of multiple IS6110 copies than beef cattle (10%). A comparison between the genotype data obtained fails to show a correlation between the main clusters found by the three techniques. However, the clustering of each genotyping procedure revealed that the majority of strains are closely related. The RFLP-PGRS patterns showed a sizable group (20.5%) containing a 5.5 kb fragment and the predominant spoligotype is similar to that from the BCG vaccine strain. Unexpectedly, four strains (2.4%) showed drug resistance to 0.2 microg/ml isoniazid and 20 microg/ml ethionamide, but none of them was resistant to rifampicin or other antibiotics tested.

Animals↗

PubMed2000

PCR-restriction enzyme analysis of a bone marrow isolate from a human immunodeficiency virus-positive patient discloses polyclonal infection with two Mycobacterium avium strains.

Polyclonal infection by Mycobacterium avium was detected by hsp65 PCR-restriction enzyme analysis (PRA) in a bone marrow isolate from an AIDS patient. Two M. avium strains, differing in colony morphology, PRA HaeIII digestion pattern, insertion element (IS) 1245 amplification, and restriction fragment length polymorphism fingerprints with IS1245 and IS1311 probes, were isolated.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Molecular epidemiology of Mycobacterium avium complex isolated from patients with and without AIDS in Brazil and England.

Mycobacterium avium complex (MAC) is ubiquitous throughout the world. It is an opportunistic pathogen in AIDS patients but the number of cases in HIV negative patients is also increasing. The aim of this study was to determine whether patients were being infected with different MAC strains or whether one strain was dominant. DNA obtained from isolates in Brazil and England were compared using pulsed field gel electrophoresis (PFGE). Strains from 22 Brazilian patients clustered into 7 groups but 68/90 patients had a unique strain. In all patients, Brazilian and English, the same strain was isolated repeatedly over time, some over several years. This study shows that it is most likely that Man is infected from the environment and that one strain can survive without change for many years both in the environment and in Man.

AIDS-Related Opportunistic Infections↗

PubMed1997

[Tuberculosis lymphadenitis in slaughtered swine from the State of São Paulo, Brazil: microscopic histopathology and demonstration of mycobacteria].

INTRODUCTION: As the occurrence of tuberculosis lymphadenitis in swine constitutes a public health risk, especially in immunosuppressed individuals, the distribution of tuberculoid lesions and the presence of microbacteria in lymph nodes and hepatic and muscular tissue in swine for slaughter, in the State of S. Paulo, SP (Brazil), in the period from 1993 to 1994, were studied. MATERIAL E METHOD: Tuberculous lesions in 60 carcasses of swine, slaughtered at abattoirs during the period 1993-1994, were studied. When macroscopic lesions were observed, a representative sampling of lymph nodes, hepatic and muscular tissues (masseter and diaphragm) were examined using histopathological and microbacterial isolation techniques. RESULTS: The macroscopic lesions were found predominantly in mesenteric lymph nodes. The MAI Complex (M.avium-intracellulare) was isolated mainly in the carcass group that showed lesions and was not found in the control group. Microorganisms of the MAI Complex were not isolated from hepatic and muscular tissues. CONCLUSION: No clear relationship between the type of mycobacteria isolated and the macroscopic lesions observed during the carcass inspection was found.

Animals↗

PubMed1995

Catalase expression, katG, and MIC of isoniazid for Mycobacterium tuberculosis isolates from São Paulo, Brazil.

The MIC of isoniazid, peroxidase-catalase expression, and the presence of the katG gene for 102 Mycobacterium tuberculosis isolates from patients in São Paulo were compared. Fifty-three isoniazid-resistant and 49 isoniazid-sensitive isolates were analyzed by polymerase chain reaction (PCR) for the presence of katG sequences. All isoniazid-sensitive and 43 (81%) isoniazid-resistant isolates expressed catalase (P = .001). None of isoniazid-sensitive and 4 (7%) of 53 isoniazid-resistant isolates lacked katG sequences. Among 6 isolates with MICs > 50 micrograms/mL, 5 (83%) did not express catalase and 2 lacked katG sequences; only 1 had complete gene deletion shown by Southern blot analysis. These findings indicate a correlation between loss of catalase and isoniazid resistance among highly resistant isolates, but these isolates were a small proportion of resistant clinical M. tuberculosis isolates from São Paulo.

Bacterial Proteins↗

PubMed1994

Single and double drug susceptibility testing of Mycobacterium avium complex and mycobacteria other than the tubercle (MOTT) bacilli by a micro-dilution broth minimum inhibitory concentration (MIC) method.

SETTING: The incidence of Mycobacterioses is increasing annually, especially in patients with AIDS. There is no clear correlation between in vitro drug susceptibility testing of mycobacteria other than the tubercle (MOTT) bacilli and the in vivo response. Although in vitro, MOTT bacilli appear resistant, some patients respond to treatment possibly as a result of a synergistic action between the drugs being used. OBJECTIVE: To produce a simple method to determine which individual drugs or combinations of drugs will be effective in killing the causative organism. DESIGN: A broth microdilution method, using microtitre plates, was used to determine the minimum inhibitory concentration (MIC) of the drugs alone and then in combination. RESULTS: It was found that the MIC values of the test drugs varied between but were constant within each of the species. Mycobacterium xenopi, M. malmoense and M. kansasii showed a large amount of susceptibility while M. avium complex, M. fortuitum and M. chelonae were limited in their response. These results were reproducible. The test was also easy to perform. The drug combination studies showed that each strain of the M. avium complex tested exhibited synergy between different combinations of drugs. CONCLUSION: This method, therefore, can be used to indicate individual or combinations of drugs that will or will not act upon the Mycobacterium species isolated. The method was also very rapid, giving a result within 7 days.

Antibiotics, Antitubercular↗

PubMedDate not supplied

Bacterial agents isolated from cerebrospinal fluid of patients with acquired immunodeficiency syndrome (AIDS) and neurological complications.

Cerebrospinal fluid (CSF) samples from 2083 patients with acquired immunodeficiency syndrome (AIDS) and neurological complications were bacteriologically examined during a period of 7 years (1984-1990). The percentage of patients who had at least one bacterial agent cultured from the CSF was 6.2%. Mycobacterium tuberculosis was the most frequently isolated agent (4.3%), followed by Mycobacterium avium complex or MAC (0.7%), Pseudomonas spp (0.5%), Enterobacter spp (0.4%), and Staphylococcus aureus (0.3%). Among 130 culture positive patients, 89 (68.5%) had M. tuberculosis and 15 (11.6%) had MAC. The frequency of bacterial isolations increased from 1988 (5.2%) to 1990 (7.2%), partly due to the increase in MAC isolations. Bacterial agents were more frequently isolated from patients in the age group 21-30 years and from women (p < 0.05).

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Mycobacterium avium complex (MAC) isolated from AIDS patients and the criteria required for its implication in disease.

Before the AIDS pandemia, the Mycobacterium avium complex (MAC) was responsible in most cases for the pneumopathies that attack patients with basic chronic pulmonary diseases such as emphysema and chronic bronchitis. In 1981, with the advent of the acquired immunodeficiency syndrome (AIDS), MAC started to represent one of the most frequent bacterial diseases among AIDS patients, with the disseminated form of the disease being the major clinical manifestation of the infection. Between January 1989 and February 1991, the Section of Mycobacteria of the Adolfo Lutz Institute, São Paulo, isolated MAC from 103 patients by culturing different sterile and no-sterile processed specimens collected from 2304 patients seen at the AIDS Reference and Training Center and/or Emilio Ribas Infectology Institute. Disseminated disease was diagnosed in 29 of those patients on the basis of MAC isolation from blood and/or bone marrow aspirate. The other 74 patients were divided into categories highly (5), moderately (26) and little suggestive of disease (43) according to the criteria of DAVIDSON (1989). The various criteria for MAC isolation from sterile and non-sterile specimens are discussed.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Drug resistance of M. tuberculosis isolated from patients with HIV infection seen at an AIDS Reference Center in São Paulo, Brazil.

M. tuberculosis-positive cultures were obtained from 228 patients seen in our service and drug sensitivity assays were carried out from January 1992 to December 1994. A survey of the medical records of these patients showed resistance to one or more drugs in 47 (20.6%), 25 of whom (10.9%), who reported previous treatment, were considered to have acquired resistance. Among the antecedents investigated, only previous treatment and alcoholism were the factors independently associated with the occurrence of resistance. The survival of patients with resistant strains was lower than that of patients attacked by non-resistant M. tuberculosis. We conclude that in the present series M. tuberculosis resistance to tuberculostatic agents was predominantly of the acquired type.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Standardization of broth microdilution method for Mycobacterium tuberculosis.

Indirect drug susceptibility tests of Mycobacterium tuberculosis was done to investigate the accuracy and feasibility of a broth microdilution method (BMM) for determining minimal inhibitory concentrations of conventional drugs against M. tuberculosis. Test drugs included isoniazid (H), rifampicin (R), ethambutol (E), streptomycin (S) and pyrazinamide (Z). Fifty isolates of M. tuberculosis from patients who had never received drug therapy, and H37Rv strain for control, were evaluated in the system. When comparing this method with the gold standard proportional method in Lowenstein-Jensen medium, sensitivity of 100% for all drugs and specifities of 91, 100, 96, 98 and 85% were observed respectively for H, R, E, S and Z. The BMM was read faster (14-20 days) than the proportional method (20-28 days). The microdilution method evaluated allows the testing of multiple drugs in multiple concentrations. It is easy to perform and does not require special equipment or expensive supplies. In contrast to radiometric method it does not use radioactive material.

Antibiotics, Antitubercular↗

PubMedDate not supplied

Multiple isolates from aids patients: aspects of an analysis by a genotypic marker and antimicrobial susceptibilities variations.

Twenty-one Mycobacterium avium multisolates, from ten human immunodeficiency virus-infected patients, were typed by restriction fragment length polymorphism using as marker the IS1245 and characterized by minimum inhibitory concentration for nine different antibiotics. Two out of four patients harboring multisolates with different fingerprint profile, were therefore considered as having a polyclonal infection, since their isolates were taken from sterile site. This result confirms that polyclonal infection caused by M. avium occurs with a nonnegligenciable frequency. Analyzing the multisolates susceptibility profile of each patient it was observed that most of them were infected with strains having appreciably different antimicrobial susceptibility patterns, no matter what the genotypic pattern of the strains was. These results have strong implication for the treatment of the patients.

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

[Infection caused by Mycobacterium tuberculosis with primary resistance to multiple drugs: a case report of a patient with AIDS].

Primary multidrug-resistant Mycobacterium tuberculosis is an important problem in the United States. There is no report in formal literature of this pathogen in Brazilian patients. CASE REPORT--We report a case of ganglionar tuberculosis diagnosed by acid-fast smears in a male, HIV positive patient. Mode of acquisition of HIV was not determined. Treatment was started, and isoniazid, rifampicin and pyrazinamide were prescribed. The patient and his family reported strict adherence to therapy, but no improvement was observed. After 75 days, the patient was admitted in our hospital because of clinical worsening. Clinical features were the presence of large submandibular and axillar lymph nodes, respiratory insufficiency and complains of abdominal pain. He died six days after admission. Culture obtained from the ganglionar aspirate disclosed M. tuberculosis susceptible to ethambutol, but resistant to isoniazid, rifampicin, pyrazinamide, ethionamide and streptomycin. DISCUSSION--Although this was a case of extrapulmonary tuberculosis, there is a concern about multidrug-resistant tuberculosis, that has been poorly evaluated in Brazil. Since high lethality and intrahospital transmission have been reported, we discuss the need of performing culture and antibiogram in suspected cases, and the prevention of the spread of M. tuberculosis to patients and health-care workers through the strict adherence to the isolation practices.

Acquired Immunodeficiency Syndrome↗