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)...

During a survey of bacterial agents that cause subclinical mastitis in water buffalos, we isolated several strains of gram-positive cocci that appeared to be enterococci except that they grew very slowly at 45°C and grew slowly in broth containing 6.5% NaCI. On the basis of the results of conventional physiologic tests, these strains were identified as Enterococcus durans. However, none of the strains reacted with the AccuProbe Enterococcus genetic probe. The whole-cell protein profiles of these organisms were compared with the profiles of Enterococcus and Lactococcus reference strains. Apart from minor quantitative differences, the mastitis isolates had indistinguishable protein profiles that were similar to the profiles of the Lactococcus garvieae and Enterococcus seriolicida type strains. The results of DNA relatedness studies performed by using the hydroxyapatite method at 55 and 70°C indicated that all of the mastitis isolates were related to the type strain of L. gawieae at the species level, despite the fact that they exhibited several uncommon phenotypic characteristics (growth at 45"C, growth in broth containing 6.5% NaCI, and failure to produce acid from mannitol and sucrose). The high levels of DNA relatedness between strains of L. garvieae and E. seriolicida demonstrated that these taxa are members of a single species. Since L. garvieae is a senior synonym of E. seriolicida, L. garvieae should be retained as the species name and strain ATCC 43921 should remain the type strain of this species.

Staphylococcus aureus is a major pathogen associated with bovine mastitis, one of the most important infectious diseases occurring in dairy cattle herds worldwide. In the present study, S. aureus isolates recovered from cows with mastitis in dairy herds located in the south-east of Brazil were genotyped by PFGE and multilocus sequence typing (MLST). PFGE identified 60 pulsotypes (PTs), which were found to be distributed among six clonal complexes (CCs) by MLST. All PTs with similarity percentages greater than 65 % belonged to the same CC. Most of the PTs belonged to CC126 (n=28) and CC97 (n=19), which were represented by 91 % of the isolates. These CCs have also been recovered from cows with mastitis in countries located in different continents, but they have rarely been isolated from human specimens. Few isolates were represented by PTs belonging to CCs that are frequently isolated from human specimens (CC1, CC5 and CC30). These data reinforce the hypothesis that a limited number of S. aureus CCs are responsible for most bovine mastitis cases internationally. Specific features of the specialized clones should be studied for use as future targets of mastitis control measures.

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BackgroundGroup B Streptococcus (GBS) remains a major cause of neonatal sepsis and is also associated with invasive and noninvasive infections in pregnant women and non-pregnant adults, elderly and patients with underlying medical conditions. Ten capsular serotypes have been recognized, and determination of their distribution within a specific population or geographical region is important as they are major targets for the development of vaccine strategies. We have evaluated the characteristics of GBS isolates recovered from individuals with infections or colonization by this microorganism, living in different geographic regions of Brazil.MethodsA total of 434 isolates were identified and serotyped by conventional phenotypic tests. The determination of antimicrobial susceptibility was performed by the disk diffusion method. Genes associated with resistance to erythromycin (ermA, ermB, mefA) and tetracycline (tetK, tetL, tetM, tetO) as well as virulence-associated genes (bac, bca, lmb, scpB) were investigated using PCR. Pulsed-field gel electrophoresis (PFGE) was used to examine the genetic diversity of macrolide-resistant and of a number of selected macrolide-susceptible isolates.ResultsOverall, serotypes Ia (27.6%), II (19.1%), Ib (18.7%) and V (13.6%) were the most predominant, followed by serotypes IV (8.1%) and III (6.7%). All the isolates were susceptible to the beta-lactam antimicrobials tested and 97% were resistant to tetracycline. Resistance to erythromycin and clindamycin were found in 4.1% and 3% of the isolates, respectively. Among the resistance genes investigated, tetM (99.3%) and tetO (1.8%) were detected among tetracycline-resistant isolates and ermA (39%) and ermB (27.6%) were found among macrolide-resistant isolates. The lmb and scpB virulence genes were detected in all isolates, while bac and bca were detected in 57 (13.1%) and 237 (54.6%) isolates, respectively. Molecular typing by PFGE showed that resistance to erythromycin was associated with a variety of clones.ConclusionThese findings indicate that GBS isolates circulating in Brazil have a variety of phenotypic and genotypic characteristics, and suggest that macrolide-resistant isolates may arise by both clonal spread and independent acquisition of resistance genes.

In the present report we describe the characteristics of 189 antimicrobial-resistant Streptococcus agalactiae isolates from bovine (38 isolates) and human (151 isolates) sources. All the strains were resistant to tetracycline (TET), and 16 (8.5%) were also resistant to erythromycin, corresponding to 23.7% of the TET-resistant bovine isolates and 4.6% of the TET-resistant human isolates. The tet(O), erm(B), and mreA resistance-related genes, as well as the bca and scpB virulence-related genes, were the most frequent among the bovine isolates, while the tet(M), erm(A), mreA, bca, lmb, and scpB genes were the most prevalent among the isolates from humans. Although a few major clusters were observed, pulsed-field gel electrophoresis results revealed a variety of profiles, reflecting the substantial genetic diversity among strains of this species isolated from either humans or bovines.Streptococcus agalactiae (group B Streptococcus [GBS]) is an important bovine pathogen, especially as a cause of both clinical and subclinical mastitis in dairy cows (23). In humans, GBS has been described as one of the most common agents of invasive infections in neonates, but it also causes invasive and noninvasive infections in adults (29). ␤-Lactam agents constitute the drugs of choice for the prophylaxis and treatment of GBS infections, since GBS isolates with confirmed resistance to these antimicrobial agents have not been observed to date (23,29). Erythromycin and other macrolides are the recommended second-line agents and the first alternative in case of allergy to ␤-lactams. Several studies, however, have documented the emergence and spread of resistance of GBS to macrolides (2, 3, 9, 10), usually in association with resistance to tetracycline.In streptococci, the most frequent macrolide resistance mechanisms are ribosomal modification by a methylase encoded by an erm gene (37) and drug efflux by a membranebound protein encoded by a mef gene (24). The presence of the Erm methylase confers resistance to erythromycin and inducible or constitutive resistance to lincosamines and streptogramin B (the macrolide-lincosamine-streptogramin B [MLS B ] phenotype), while the presence of the Mef pump confers resistance to 14-and 15-membered macrolides (M phenotype). An additional efflux mechanism, encoded by the mreA gene, has been described in GBS (8). The linB gene, described in Enterococcus faecium (4), was recently detected in a GBS isolate (10).Although resistance to tetracycline among GBS isolates is frequently found at high rates and, therefore, tetracycline is no longer indicated for the treatment of GBS infections, tetracycline resistance genes are often found on the same motile unit as the erythromycin resistance genes (33), raising concern about the role of tetracycline-resistant strains in the spread of erythromycin-resistant strains. A variety of tetracycline resistance genes have been described to date, and most of them encode either a protein which pumps tetracycline out of the cell or a ribosomal protein which protects the r...

Capsular serotype surveillance of clinical isolates of Streptococcus pneumoniae is essential for evaluation of the potential impact of introducing multivalent capsular serotype-based vaccines in Latin America. Here, a previously described sequential multiplex PCR method was revised for optimal targeting of prevalent serotypes in Latin America. The revised protocol successfully serotyped 139/147 pneumococci (94.6 %) from Brazilian children, demonstrating a labour-efficient, accurate method requiring only conventional PCR capability.

Multidrug-resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. The existence of metallo-␤-lactamase-and extended-spectrum ␤-lactamase-producing isolates exhibiting resistance to most ␤-lactam antimicrobial agents greatly complicates the clinical management of patients infected with such isolates. Since 1998, P. aeruginosa isolates resistant to all commercially available antimicrobial agents have been detected at a university-affiliated public hospital in Rio de Janeiro, Brazil. The present study was designed to characterize the antimicrobial resistance profiles and the genetic diversity of the P. aeruginosa strains isolated at this hospital and four private hospitals in Rio de Janeiro. Between April 1999 and March 2000, 200 consecutive isolates were obtained and analyzed for antimicrobial resistance. The genetic diversity of a selected number of them was evaluated by pulsed-field gel electrophoresis and PCR with the ERIC-2 primer. A predominant genotype, designated genotype A, was identified among isolates from four of the five hospitals evaluated. Eighty-four ceftazidime-resistant isolates were evaluated for metallo-␤-lactamase production, which was detected in 20 (91%) of 22 genotype A isolates and 11 (18%) of 62 isolates belonging to other genotypes (P < 0.05). Two metallo-␤-lactamase-producing genotype A isolates also produced an extended-spectrum ␤-lactamase. The occurrence of multidrug-resistant P. aeruginosa strains belonging to a unique genotype in different hospitals in Rio de Janeiro underscores the importance of the contribution of a single clone to the increase in the incidence of multidrug-resistant P. aeruginosa nosocomial infections.