Mycobacterium leprae and Mycobacterium tuberculosis antimicrobial resistance has been followed with great concern during the last years, while the need for new drugs able to control leprosy and ...tuberculosis, mainly due to extensively drug-resistant tuberculosis (XDR-TB), is pressing. Our group recently showed that M. leprae is able to induce lipid body biogenesis and cholesterol accumulation in macrophages and Schwann cells, facilitating its viability and replication. Considering these previous results, we investigated the efficacies of two statins on the intracellular viability of mycobacteria within the macrophage, as well as the effect of atorvastatin on M. leprae infections in BALB/c mice. We observed that intracellular mycobacteria viability decreased markedly after incubation with both statins, but atorvastatin showed the best inhibitory effect when combined with rifampin. Using Shepard's model, we observed with atorvastatin an efficacy in controlling M. leprae and inflammatory infiltrate in the BALB/c footpad, in a serum cholesterol level-dependent way. We conclude that statins contribute to macrophage-bactericidal activity against Mycobacterium bovis, M. leprae, and M. tuberculosis. It is likely that the association of statins with the actual multidrug therapy effectively reduces mycobacterial viability and tissue lesion in leprosy and tuberculosis patients, although epidemiological studies are still needed for confirmation.
An epidemic of infections after video-assisted surgery (1,051 possible cases) caused by rapidly growing mycobacteria (RGM) and involving 63 hospitals in the state of Rio de Janeiro, Brazil, occurred ...between August 2006 and July 2007. One hundred ninety-seven cases were confirmed by positive acid-fast staining and/or culture techniques. Thirty-eight hospitals had cases confirmed by mycobacterial culture, with a total of 148 available isolates recovered from 146 patients. Most (n = 144; 97.2%) isolates presented a PRA-hsp65 restriction pattern suggestive of Mycobacterium bolletii or Mycobacterium massiliense. Seventy-four of these isolates were further identified by hsp65 or rpoB partial sequencing, confirming the species identification as M. massiliense. Epidemic isolates showed susceptibility to amikacin (MIC at which 90% of the tested isolates are inhibited MIC₉₀, 8 μg/ml) and clarithromycin (MIC₉₀, 0.25 μg/ml) but resistance to ciprofloxacin (MIC₉₀, greater-than-or-equal32 μg/ml), cefoxitin (MIC₉₀, 128 μg/ml), and doxycycline (MIC₉₀, greater-than-or-equal64 μg/ml). Representative epidemic M. massiliense isolates that were randomly selected, including at least one isolate from each hospital where confirmed cases were detected, belonged to a single clone, as indicated by the analysis of pulsed-field gel electrophoresis (PFGE) patterns. They also had the same PFGE pattern as that previously observed in two outbreaks that occurred in other Brazilian cities; we designated this clone BRA100. All five BRA100 M. massiliense isolates tested presented consistent tolerance to 2% glutaraldehyde. This is the largest epidemic of postsurgical infections caused by RGM reported in the literature to date in Brazil.
Background and Aims Attention to patient safety has increased recently due to outbreaks of nosocomial infections associated with GI endoscopy. The aim of this study was to evaluate current cleaning ...and disinfection procedures of endoscope channels with high bioburden and biofilm analysis, including the use of resistant mycobacteria associated with postsurgical infections in Brazil. Methods Twenty-seven original endoscope channels were contaminated with organic soil containing 108 colony-forming units/mL of Pseudomonas aeruginosa , Staphylococcus aureus , or Mycobacterium abscessus subsp bolletii. Biofilms with the same microorganisms were developed on the inner surface of channels with the initial inoculum of 105 colony-forming units/mL. Channels were reprocessed following current protocol, and samples from cleaning and disinfection steps were analyzed by bioluminescence for adenosine triphosphate, cultures for viable microorganisms, and confocal microscopy. Results After contamination, adenosine triphosphate levels increased dramatically, and high bacterial growth was observed in all cultures. After cleaning, adenosine triphosphate levels decreased to values comparable to precontamination levels, and bacterial growth was demonstrated in 5 of 27 catheters, 2 with P aeruginosa and 3 with M abscessus . With regard to induced biofilm, a remarkable reduction occurred after cleaning, but significant microbial growth inhibition occurred only after disinfection. Nevertheless, viable microorganisms within the biofilm were still detected by confocal microscopy, more so with glutaraldehyde than with peracetic acid or O -phataladehyde. Conclusion After the complete disinfection procedure, viable microorganisms could still be detected within the biofilm on endoscope channels. Prevention of biofilm development within endoscope channels should be a priority in disinfection procedures, particularly for ERCP and EUS.
Bacillus Calmette-Guérin (BCG) is the only vaccine licensed against tuberculosis. Despite the protection offered by the vaccine, in some circumstances children and immunocompromised individuals can ...develop associated infections, known as BCGitis. Drug susceptibility patterns of BCG clinical strains have rarely been described. We aimed to describe the susceptibility pattern of BCG clinical strains isolated in two different countries.
We performed culture-based drug susceptibility testing of thirty one BCG strains isolated from patients in Brazil (n=5, 16%) and Argentina (n=26, 84%) using the broth micro-dilution method (phenotypic method). Final antibiotic concentrations for susceptibility testing ranged from 0.5 to 16 mg/L for amikacin, 0.3125 to 10 mg/L for ethambutol, 0.05 to 1.6 mg/L for isoniazid and 0.25 to 8 mg/L for rifampicin, streptomycin and ofloxacin. Additionally, we compared the results with genetic data obtained by whole genome sequencing.
By using the phenotypic method we detected one strain resistant to ethambutol, three strains resistant to rifampicin and one resistant to isoniazid. Additionally, two strains that were phenotypically resistant to both isoniazid and rifampicin carried mutations in the
and
genes simultaneously.
There is evidence of the emergence of BCG-resistant strains isolated from vaccine-related complications. We recommend drug susceptibility testing of the BCG strain causing the infection in order to prevent treatment failure.
Highlights • Rapidly growing mycobacteria (RGM) are opportunistic pathogens associated with outbreaks. • Conventional identification of RGM species is laborious and uncertain. • Molecular techniques ...provide relevant information on diagnosis and clonality. • Multilocus enzyme electrophoresis (MLEE) was found to be a powerful tool for the identification and typing of epidemic RGM species.
In 2005 and 2006, 8,121 clinical specimens submitted to the Mycobacteriology Laboratory of the Clementino Fraga Filho University Hospital/Thoracic Diseases Institute, in the city of Rio de Janeiro, ...Brazil, were inoculated on Löwenstein-Jensen medium containing glycerol and pyruvate. There were 79 mycobacteria isolates that presented growth only on pyruvate-containing medium, and those isolates were selected for the presumptive identification of Mycobacterium bovis. The selected isolates were screened with biochemical tests, PCR amplification (with the specific primers Rv0577 and Rv1510), and pyrazinamide susceptibility tests. All of the strains isolated showed specific phenotypical and genotypical patterns characteristic of M. tuberculosis, and no M. bovis strains were detected.
To evaluate the minimum inhibitory concentration (MIC) of GTA against these microorganisms and alternative disinfectants for high-level disinfection (HLD).
Reference mycobacteria and clinical M. ...massiliense strains were included in this study. Active cultures were submitted to susceptibility qualitative tests with GTA dilutions (ranging from 1.5% to 8%), and commercial orthophthaldehyde (OPA) and peracetic acid (PA)-based solutions, during the period of exposure as recommended by National Agency of Sanitary Surveillance for HLD.
All reference and M. massiliense non-BRA100 strains, recovered from sputum, were susceptible to any GTA concentration, OPA and PA solutions. M. massiliense BRA100 strains presented MIC of 8% GTA and were susceptible to OPA and PA.
M. massiliense BRA100 strain is resistant to high GTA concentrations (up to 7%), which proves that this product is non-effective against specific rapidly growing mycobacteria and should be substituted by OPA or PA-based solutions for HLD.
The aim of this study was to determine the prevalence of
non-tuberculous mycobacteria (NTM) isolates at University Hospital,
Reference Center for Aids in Rio de Janeiro, Brazil, during one year.
We ...used standard biochemical tests for species identification and
IS1245 PCR amplification was applied as a Mycobacterium avium
specific identification marker. Four hundred and four specimens from
233 patients yielded acid-fast bacilli growth. M. tuberculosis was
identified in 85% of the patients and NTM in 15%. NTM disseminated
infection was a common event correlated with human immunodeficiency
virus (HIV) infected patients and only in HIV negative patients the
source of NTM was non sterile site. M. avium complex (MAC) was
biochemically identified in 57.8% (49/83) of NTM isolates, most of them
from sterile sites (75.5%), and in 94% (46/49) the IS 1245 marker
specific for M. avium was present. Twenty NTM strains showed a MAC
biochemical pattern with the exception of a urease-positive (99% of MAC
are urease-negative), however IS1245 was detected in 96% of the strains
leading to their identification as M. avium . In this group differences
in NTM source was not significant. The second most frequently isolated
NTM was identified as M. scrofulaceum (7.2%), followed by M. terrae
(3.6%), M. gordonae (2.4%), M. chelonae (1.2%), M. fortuitum (1.2%) and
one strain which could not be identified. All were IS1245 negative
except for one strain identified as M. scrofulaceum . It is interesting
to note that non-sterile sites were the major source of these isolates
(92.8%). Our finding indicated that M. avium is still the major
atypical species among in the MAC isolates recovered from Brazilian
Aids patients without highty active antiretroviral therapy schema. Some
discrepancies were seen between the identification methods and further
investigations must be done to better characterize NTM isolates using
other phenotypic and genotypic methods.
The occurrence of mycobacteriosis caused by
Mycobacterium marinum in a commercial breeding farm of bullfrogs (
Rana catesbeiana) in Rio de Janeiro, Brazil is described. Ten animals presented skin ...lesions on the head and extremities. These and 38 other asymptomatic adult animals from various tanks were killed and at necropsy disseminated granulomatous lesions were observed in the 10 clinically affected animals and in 16 (42.1%) of the asymptomatic frogs. Acid-fast bacilli were observed in all smears of the 10 symptomatic frogs and in all but one from the 16 asymptomatic animals with visceral lesions. Ten samples from the 25 positive animals were randomly selected for culture which yielded four isolates of fast-growing (<7 days) mycobacteria. Those purified isolates were characterised by biochemical traditional means as
M. marinum. Identification of the strains was confirmed using reverse-phase high-performance liquid chromatography and a polymerase chain reaction (PCR) restriction enzyme analysis assay. It is suggested that
M. marinum is an important agent of granulomatous disease in bullfrogs and that infected animals, even when asymptomatic, could act as reservoirs spreading the disease and contaminating other frogs in the farm.
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