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 [MIC 90 ], 8 g/ml) and clarithromycin (MIC 90 , 0.25 g/ml) but resistance to ciprofloxacin (MIC 90 , >32 g/ml), cefoxitin (MIC 90 , 128 g/ml), and doxycycline (MIC 90 , >64 g/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.Outbreaks, pseudooutbreaks, and cases of health-care-associated infections caused by rapidly growing mycobacteria (RGM) have been reported since the first case was described in 1938 (13). In virtually all nosocomial infections caused by this group of microorganisms, there were failings in the sterilization processes of solutions, surgical instruments, or medical devices (13,14,45). Recent publications indicate an increasing number of infections secondary to breast augmentation and video-assisted surgeries (7,9,19,23,25,(40)(41)(42)(43).The growing number of cases and reports may be due, at least in part, to the well-known tolerance to alkaline glutaraldehyde among Mycobacterium chelonae-Mycobacterium abscessus group isolates and to the low susceptibility to high-level disinfectants (20,22,39).Outbreaks of RGM infections unrelated to medical procedures also can occur and usually are associated with exposure to recreational water containing a large number of bacteria and inadequate chlorination (15,44), highlighting the ubiquity of these organisms in the environment. In fact, RGM have been recovered from many different environmental sources, including soil and water distribution systems (8,45). RGM are considered opportunistic pathogens and can cause chronic lung disease, particularly the species included in the M. chelonae-M. abscessus group (8, 46)...
This study evaluated the oxacillin susceptibilities of 152 coagulase-negative staphylococcal (CoNS) strains of 12 species by disk diffusion; agar dilution; E-test; the slide latex agglutination test (Slidex MRSA Detection test; bioMérieux S/A, Paris, France); the agar screening test with 1, 2, 4, or 6 g of oxacillin per ml and incubation for 24 or 48 h; and detection of the mecA gene by PCR. The results revealed that the agar screening test with 4 g of oxacillin per ml and incubation for 48 h was superior to any single phenotype-based susceptibility assay, presenting a sensitivity and a specificity of 100% each. For the different methods evaluated, the sensitivities and specificities were as follows: for disk diffusion, 94.2 and 91.8%, respectively; for the agar dilution test 100 and 73.5%, respectively; for E-test, 100 and 71.4%, respectively; and for the slide latex agglutination test, 97.1 and 98%, respectively. A good correlation was observed between oxacillin susceptibility testing results and PCR results for Staphylococcus epidermidis, S. haemolyticus, S. hominis subsp. hominis, and all mecA-positive strains. However, at least 60% of the mecA-negative isolates of the species S. saprophyticus, S. cohnii subsp. urealyticum, S. lugdunensis, and S. sciuri were erroneously classified as oxacillin resistant by the agar dilution test. Conversely, the slide latex agglutination test presented a high sensitivity (97.1%) and a high specificity (98%) for all CoNS species. Our results demonstrated the accuracy of the agar screening test with 4 g of oxacillin per ml and incubation for 48 h and the slide latex agglutination test for the appropriate detection of the oxacillin susceptibilities of CoNS isolates. Both assays are technically simple and can be easier to perform in routine laboratories than PCR.
BackgroundMutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains.ResultsWe, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH ≥2 μg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families.ConclusionOur data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.
A cross-sectional survey was carried out in 2003 to investigate the epidemiology of tuberculosis (TB) among the Suruí Indians, Brazilian Amazon. A total of 736 subjects (50.7% females) were examined (80% of the total population). TB suspects underwent standardised evaluation for the presence of signs and/or symptoms of active TB, including chest radiography, PPD skin test, sputum microscopy examination for acid-fast bacilli and mycobacterial culture. A Bacillus Calmette-Guerin vaccine scar was detected in 699 individuals (95.0%). Of all the individuals examined, 120 (16.3%) had undergone previous TB treatment (46.7% females). One hundred and nine individuals were assessed as TB suspects (52.3% females). The survey identified six new cases of TB in the Suruí (three men and three women). Five of the six cases came from only two of the ten villages. Mycobacterium tuberculosis colonies grew from 5 (4.6%) samples (only two of which were also smear-positive) and mycobacteria other than M. tuberculosis were isolated from 14 (12.8%) samples. Diagnosis of TB based exclusively on clinical grounds was established only in the case of a 4-year-old girl. Based on this survey, the prevalence of active TB in the sampled group (N=736) was 815.2 per 100000. This study highlights the urgent need to review and strengthen control strategies directed at indigenous peoples in the country, taking into consideration their social, cultural and environmental differences.
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