First Report of a Wastewater Treatment-Adapted Enterococcus faecalis ST21 Harboring vanA Gene in Brazil.

Enterococcus faecalis has emerged as an important opportunistic pathogen due to its increasing resistance to antimicrobials, mainly to vancomycin, which leads substantial cases of therapeutic failures. Wastewater treatment plants (WWTP), in turn, are considered hotpots in the spread of antimicrobial resistance according to One Health perspective. In this study, we present the first report of a vancomycin-resistant E. faecalis strain recovered from treated effluent in Brazil. For this purpose, the whole-genome sequencing (WGS) was carried out aiming to elucidate its molecular mechanisms of antimicrobial resistance and its phylogenetic relationships amongst strains from other sources and countries. According to Multilocus Sequence Typing (MLST) analysis this strain belongs to ST21. The WGS pointed the presence of vanA operon, multiple antibiotic resistance and virulence genes, and a significant pathogenic potential for humans. The phylogenomic analysis of E. faecalis 6805 was performed with ST21 representatives from the PubMLST database, including the E. faecalis IE81 strain from clinical sample in Brazil, which had its genome sequenced in this study. Our results demonstrated a strain showing resistance to vancomycin in treated effluent. To the best of our knowledge, this is an unprecedented report of vanA-carrying E. faecalis ST21. Furthermore, it is the first description of a vanA-harboring strain of this species from environmental sample in Brazil. Our data highlight the role of WWTP in the spread of AMR, since these environments are favorable for the selection of multidrug-resistant pathogens and the treated effluents, carrying antibiotic resistance genes, are directed to receiving water bodies.

Prevalence, capsular types, antimicrobial resistance and risk factors associated with pneumococcal carriage among children after long-term 10-valent pneumococcal conjugate vaccine use in Brazil.

BACKGROUND: The 10-valent pneumococcal conjugate vaccine (PCV10) was introduced for childhood vaccination in Brazil's National Immunization Program in 2010. After nine years of PCV10 use, we investigated the carriage prevalence, capsular types, antimicrobial resistance and risk factors among children living in Niterói city, RJ, Brazil. METHODS: Between September and December 2019, we conducted a cross-sectional study and recruited children under 6 years of age. Antimicrobial susceptibility was evaluated by the disk-diffusion method and MICs to beta-lactams and macrolides were determined by E-test®. Capsular types were deduced by multiplex PCR. Logistic regression was used to predict risk factors for pneumococcal carriage. RESULTS: Seventy-five (17.4%) of the 430 children were pneumococcal carriers. The most frequent capsular types were 6C/D (14.7%), 11A/D (13.3%), and 23B (9.3%). PCV10 serotypes represented 5.3%. All isolates were susceptible to levofloxacin, linezolid, rifampicin, and vancomycin. Penicillin non-susceptible pneumococci (PNSP) made up 37.3%, with penicillin and ceftriaxone MICs ranging from 0.12 to 4.0 µg/ml and 0.064-4.0 µg/ml, respectively. Of the 19 (25.3%) erythromycin-resistant (ERY-R) isolates (macrolide MICs of 6 to >256 µg/ml), most had the cMLSB phenotype (84.2%) and carried the erm(B) gene (73.7%). We detected 17 (22.6%) multidrug-resistant (MDR) isolates, strongly associated with serotype 6C/D. Presence of any symptoms, chronic diseases, childcare center attendance, living with young siblings, slum residence, and unstable income were predictors of pneumococcal carriage. CONCLUSIONS: Long-term universal childhood use of PCV10 has nearly eliminated carriage with PCV10 serotypes, but the high frequency of MDR isolates, especially associated with serotype 6C/D, remains a concern. Replacing PCV10 with PCV13 should reduce the proportion of ERY-R isolates and PNSP by at least 14% and 18%, respectively.

Description of optochin-resistant Streptococcus pneumoniae due to an uncommon mutation in the atpA gene and comparison with previously identified atpC mutants from Brazil.

Optochin susceptibility testing is a major assay used for presumptive identification of Streptococcus pneumoniae. Still, atypical optochin-resistant (Optr) pneumococci have been reported and this phenotype has been attributed to nucleotide substitutions in the genes coding for the F0F1ATPase. While substitutions in the atpC gene (c-subunit of ATPase) are more common and better characterized, data on mutations in the atpA (a-subunit) are still limited. We have characterized five Optr isolates presenting alterations in the atpA (Trp206Cys in four isolates and Trp206Ser in one isolate), constituting the first report of such mutations in Brazil. Most of the Optr isolates consisted of heterogeneous populations. Except for Opt MICs and the nucleotide changes in the atpA gene, Optr and Opts subpopulations originating from the same culture had identical characteristics. In addition, we compared phenotypic and genetic characteristics of these atpA mutants with those of atpC mutants previously identified in Brazil. No structural alterations were detected among predicted proteins, regardless of mutations in the coding gene, suggesting that, despite the occurrence of mutations, protein structures tend to be highly conserved, ensuring their functionalities. Phylogenetic analysis revealed that atypical Optr strains are true pneumococci and Opt resistance does not represent any apparent selective advantage for clinical isolates.

Biofilm Formation on Breast Implant Surfaces by Major Gram-Positive Bacterial Pathogens.

BACKGROUND: Bacterial biofilm on surfaces of mammary implants is a predisposing factor for several outcomes. Because Gram-positive bacteria are potential agents of biomaterial-associated infections (BAIs), their abilities to form biofilm on breast implants should be elucidated. OBJECTIVES: The aim of this study was to evaluate biofilm formation on different mammary prosthesis surfaces by major Gram-positive bacterial pathogens involved in BAIs. METHODS: We initially evaluated biofilm formation on polystyrene plates with and without fibrinogen or collagen for 1 reference strain and 1 clinical isolate of Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. We also tested the ability of clinical isolates to form biofilm on 4 different implant surfaces: polyurethane foam and smooth, microtextured, and standard textured silicone. Biofilm structure and cell viability were observed by scanning electron microscopy and confocal laser scanning microscopy. RESULTS: All strains showed strong biofilm formation on polystyrene. After fibrinogen or collagen treatment, biofilm formation varied. With fibrinogen, reference strains of S. aureus and S. pyogenes increased biofilm formation (P < 0.05). Reference strains of all species and the clinical isolate of S. pyogenes increased biofilm formation after collagen treatment (P < 0.05). In general, S. aureus showed higher capacity to produce biofilm. Scanning electron microscopy showed that biofilm attached to all surfaces tested, with the presence of extracellular polymeric substances and voids. Viable cells were more frequent for E. faecalis and S. pyogenes. CONCLUSIONS: All species produced biofilm on all prosthesis surfaces and under different conditions. Micrographies indicated thicker bacterial biofilm formation on microtextured and/or standard textured silicone by all species, except E. faecalis.

Direct effect of the 13-valent pneumococcal conjugate vaccine use on pneumococcal colonization among children in Brazil.

BACKGROUND: The 13-valent pneumococcal conjugate vaccine (PCV13) has been commercially available in Brazil since 2010. We investigated the carriage prevalence, capsular types, and antimicrobial resistance among pneumococci isolated from children immunized with PCV13 in Brazil. METHODS: We analyzed 500 children < 6 years old attending public (n = 270) and private (n = 230) clinics in Niterói/RJ, Brazil, in 2014. We determined the antimicrobial susceptibility and capsular types for all isolates. RESULTS: Thirty-eight (7.6%) of 500 children had received at least one PCV13 dose. Since only two (0.7%) of 270 children at the public clinic were vaccinated with PCV13, major analyses focused on 36 (15.7%) of 230 children attending private clinics. Nine (25%) of 36 children were pneumococcal carriers. Characteristics associated with carriage were age ≥ 2 years, cough/expectoration, and childcare center attendance (p ≤ 0.01). The capsular types found were 15B/C (n = 2), 6C, 11A/D, 16F, 23A, and 23F. Two isolates were non-typeable (NT). Three (33.3%) isolates were multidrug resistant. We found four (44.4%) penicillin non-susceptible pneumococci, with penicillin and ceftriaxone MICs ranging from 0.12 to 4.0 µg/ml and 0.023-0.5 µg/ml, respectively. We also detected two (22.2%) erythromycin-resistant isolates (MICs of 3.0 and 256 µg/ml). CONCLUSIONS: Colonization with PCV13 serotype was rare among the vaccinated children. Increasing PCV13 coverage might help reduce the frequency of major serotypes currently associated with invasive pneumococcal diseases in Brazil, such as 3 and 19A. The isolation of multidrug-resistant serotype 6C and NT isolates in carriage, however, requires close monitoring.

Population structure of Streptococcus pneumoniae colonizing children before and after universal use of pneumococcal conjugate vaccines in Brazil: emergence and expansion of the MDR serotype 6C-CC386 lineage.

Objectives: To determine the population structure and change in drug resistance of pneumococci colonizing children before and after the introduction of the 10-valent and 13-valent pneumococcal conjugate vaccines (PCV10/13) in Brazil. Methods: We used MLST to analyse 256 pneumococcal isolates obtained from children aged <6 years before (2009-10; n = 125) and after (2014; n = 131) the introduction of the PCV10 and PCV13. Antimicrobial susceptibility and capsular types were previously determined. Results: We identified 97 different STs. Ninety (35.2%) isolates were related to international clones. The most frequent lineages were serogroup 6-CC724 (where CC stands for clonal complex) and the MDR serotype 6C-CC386 in the pre- and post-PCV10/13 periods, respectively. Penicillin-non-susceptible pneumococci (PNSP) formed 24% and 38.9% of the pre- and post-PCV10/13 isolates, respectively (P = 0.01). In the pre-PCV10/13 period, serotype 14-ST156 was the predominant penicillin-non-susceptible lineage, but it was not detected in the post-PCV10/13 period. Serotype 14-ST156 and serotype 19A-ST320 complex isolates had the highest penicillin and ceftriaxone MICs in the pre- and post-PCV10/13 periods, respectively. In turn, serotype 6C-CC386 comprised almost 30% of the PNSP and over 40% of the erythromycin-resistant isolates (MIC >256 mg/L) in the post-PCV10/13 period. Conclusions: Although PNSP strains were polyclonal, most resistant isolates belonged to a single genotype from each period. Higher erythromycin resistance prevalence (42%) in the post-PCV10/13 period was mainly attributed to MDR serotype 6C-CC386. Ongoing surveillance of pneumococcal clonal composition is important to evaluate PCV use outcomes and to identify factors other than PCVs that drive pneumococcal drug resistance evolution.

Major globally disseminated clonal complexes of antimicrobial resistant enterococci associated with infections in cancer patients in Brazil.

Cancer and hematological malignancies constitute major comorbidities in enterococcal infections, but little is known about the characteristics of enterococci affecting cancer patients. The aim of this study was to characterize 132 enterococcal clinical isolates obtained from cancer patients attending a Cancer Reference Center in Brazil between April 2013 and March 2014. Susceptibility to 17 antimicrobial agents was assessed by disk diffusion method. Resistance and virulence genes were investigated by PCR. Multilocus sequence typing (MLST) was performed for selected Enterococcus faecalis and Enterococcus faecium isolates. The predominant species was E. faecalis (108 isolates), followed by E. faecium (18), Enterococcus gallinarum (3), Enterococcus avium (2) and Enterococcus durans (1). Multidrug-resistant (MDR) isolates made up 44.7%, but all isolates were susceptible to fosfomycin, linezolid and glycopeptides. The most prevalent genes associated with erythromycin- and tetracycline-non susceptible isolates were erm(B) (47/71; 66.2%) and tet(M) (24/68; 35.3%), respectively. High-level resistance (HLR) to gentamicin was found in 22 (16.7%) isolates and 13 (59.1%) of them carried the aac(6')-Ie-aph(2″)-Ia gene. HLR to streptomycin was detected in 34 (25.8%) isolates, of which 15 (44.1%) isolates had the ant(6')-Ia gene. The most common virulence genes were gelE (48.9%), esp (30.5%) and asa1 (29.8%). MLST performed for 26 E. faecalis isolates revealed 18 different sequence-types (STs), with seven corresponding to novel STs (625, 626, 627, 628, 629, 630, and 635). On the other hand, nine of 10 E. faecium isolates analyzed by MLST belonged to a single clonal complex, comprised of mostly ST412, which emerged worldwide after mid-2000s, but also two novel STs (963 and 964). We detected major globally disseminated E. faecalis and E. faecium clonal complexes along with novel closely related STs, indicating the fitness and continuous evolution of these hospital-adapted lineages.

Pneumococcal carriage among children after four years of routine 10-valent pneumococcal conjugate vaccine use in Brazil: The emergence of multidrug resistant serotype 6C.

BACKGROUND: In 2010, the 10-valent pneumococcal conjugate vaccine (PCV10) was introduced free of charge in Brazil as part of the public immunization program. Here we investigated the carriage prevalence, colonization risk factors, capsular types, and antimicrobial resistance among pneumococcal isolates obtained from children in Brazil four years after routine PCV10 use. METHODS: Between September and December 2014, we conducted a cross-sectional study among children<6years old who attended one public and two private clinics in Niterói, RJ, Brazil to evaluate pneumococcal nasopharyngeal carriage. Antimicrobial susceptibility and capsular types were determined for all isolates. RESULTS: Of 522 children, 118 (22.6%) were pneumococcal carriers. Being≥2years old, attending childcare center, presenting with any symptoms, having acute or chronic respiratory disease, and residing in a slum were associated with pneumococcal carriage. The most prevalent capsular types were 6C (14.5%), 15B/C (11.5%), 11A/D (9.2%), and 6A (7.6%). PCV10 serotypes represented 2.5%. All isolates were susceptible to levofloxacin, rifampicin, and vancomycin. Penicillin non-susceptible pneumococci (PNSP) comprised 39%, with penicillin and ceftriaxone MICs ranging from 0.12-8.0µg/ml and 0.012-1.0µg/ml, respectively. The 33 (28%) erythromycin-resistant isolates (MICs of 1.5 to >256µg/ml) displayed the cMLSB (72.7%) or M (27.3%) phenotypes, harboring the erm(B) and/or mef(A/E) genes. High non-susceptibility rates (>20%) to clindamycin, erythromycin, penicillin, and tetracycline were largely explained by the prevalence of multidrug resistant (MDR) serotype 6C isolates. CONCLUSIONS: Effects of universal childhood PCV10 use on carriage were evident, with the near elimination of PCV10 serotypes. The emergence of MDR serotype 6C isolates, however, is a concern. Ongoing surveillance to monitor serotype 6C increase in invasive diseases is warranted.

Potential of MALDI-TOF MS as an alternative approach for capsular typing Streptococcus pneumoniae isolates.

Streptococcus pneumoniae can be classified in more than 90 capsular types, as traditionally determined by serological methods and more recently by PCR-based techniques. Such methods, however, can be expensive, laborious or unable to accurately discriminate among certain serotypes. Therefore, determination of capsular types, although extremely important for epidemiological purposes and for estimating the impact of pneumococcal conjugate vaccines, is mainly restricted to research laboratories, being rarely performed in the clinical setting. In the present study, MALDI-TOF MS was evaluated as an alternative tool to characterize 416 pneumococcal isolates belonging to serotypes 6A, 6B, 6C, 9N, 9V or 14. For MALDI-TOF MS analysis, each isolate was submitted to an extraction protocol using formic acid and acetonitrile. Measurements were performed with a Bruker Microflex LT mass spectrometer using default parameters and generating spectra in the range of 2,000-20,000 m/z. Spectra were analyzed with the BioNumerics software v7.6. Isolates were mainly distributed according to the capsular type in a Neighbor Joining tree and serotypes investigated were successfully discriminated by the presence/absence of 14 selected biomarkers. The results suggest that MALDI-TOF MS is a promising alternative for typing pneumococcal strains, highlighting its usefulness for rapid and cost-effective routine application in clinical laboratories.

Characterization of Ciprofloxacin-Resistant and Ciprofloxacin-Susceptible Uropathogenic Escherichia coli Obtained from Patients with Gynecological Cancer.

The objective of this work was to assess the genetic characteristics of uropathogenic Escherichia coli, ciprofloxacin resistance or susceptibility, obtained from patients with gynecological cancer and urinary tract infection (UTI). Seventy-seven E. coli ciprofloxacin-resistant isolates and 38 ciprofloxacin-susceptible were analyzed by polymerase chain reaction (PCR) to determine the phylogenetic groups, virulence factors as iucC, fyuA, hlyC, cnf1 genes, and pks pathogenicity island. The presence of genes related to ciprofloxacin resistance such as qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA, and the sequencing of DNA gyrase genes and topoisomerase IV were determined. The genetic profile of the isolates was determined by pulsed-field gel electrophoresis (PFGE). Statistical analysis was performed using Fisher's exact test and Chi-square test. Phylogenetic group B2 was the most prevalent although a great genetic diversity was observed by PFGE. Only genes associated to siderophores were found in ciprofloxacin-resistant isolates; however, in ciprofloxacin-susceptible isolates, genes related to siderophores and toxin, were detected. Additionally qnrB was detected in both populations, ciprofloxacin resistant and susceptible. DNA mutations in gyrA were Ser-83-Leu and Asp-87-Asn and in parC were Ser-80-Ile and Glu-84-Val, Glu-84-Lys. In conclusion, it was observed a high prevalence of qnrB in the population studied; in addition, it was the first time the pks island was observed only in ciprofloxacin-susceptible isolates.

Antimicrobial susceptibility patterns, emm type distribution and genetic diversity of Streptococcus pyogenes recovered in Brazil.

Streptococcus pyogenes is responsible for a variety of infectious diseases and immunological complications. In this study, 91 isolates of S. pyogenes recovered from oropharynx secretions were submitted to antimicrobial susceptibility testing, emm typing and pulsed-field gel electrophoresis (PFGE) analysis. All isolates were susceptible to ceftriaxone, levofloxacin, penicillin G and vancomycin. Resistance to erythromycin and clindamycin was 15.4%, which is higher than previous reports from this area, while 20.9% of the isolates were not susceptible to tetracycline. The macrolide resistance phenotypes were cMLSB (10) and iMLSB (4). The ermB gene was predominant, followed by the ermA gene. Thirty-two emm types and subtypes were found, but five (emm1, emm4, emm12, emm22, emm81) were detected in 48% of the isolates. Three new emm subtypes were identified (emm1.74, emm58.14, emm76.7). There was a strong association between emm type and PFGE clustering. A variety of PFGE profiles as well as emm types were found among tetracycline and erythromycin-resistant isolates, demonstrating that antimicrobial resistant strains do not result from the expansion of one or a few clones. This study provides epidemiological data that contribute to the development of suitable strategies for the prevention and treatment of such infections in a poorly studied area.

Phenotypic and molecular characterization of optochin-resistant Streptococcus pneumoniae isolates from Brazil, with description of five novel mutations in the ATPC gene.

Optochin (Opt) susceptibility is used largely for the identification of Streptococcus pneumoniae in diagnostic laboratories. Opt-resistant (Opt(r)) S. pneumoniae isolates have been reported, however, indicating the potential for misidentification of this important pathogen. Point mutations in the atpC gene have been associated with the emergence of Opt(r) S. pneumoniae, but data on the characterization of such atypical variants of S. pneumoniae are still limited. The present report describes the results of a polyphasic approach to identifying and characterizing 26 Opt(r) S. pneumoniae isolates recovered from patients or carriers living in Brazil. Sixteen isolates consisted of heterogeneous populations, and 10 isolates were homogeneously Opt(r). The isolates had different serotypes and antimicrobial susceptibility profiles. They also presented diverse genetic characteristics, as indicated by pulsed-field gel electrophoresis (PFGE), multilocus variable-number tandem-repeat analysis (MLVA), and pspA gene typing. Except for Opt MICs (4- to 64-fold higher among Opt(r) variants), Opt(r) and Opt-susceptible (Opt(s)) subpopulations originating from the same culture had identical characteristics. Sequencing of the atpC gene of the Opt(r) variants revealed 13 different nucleotide changes distributed among eight different codons. Changes in codon 49 were the most frequent, suggesting that this might be a hot spot for optochin resistance-conferring mutations. On the other hand, five novel types of mutations in the atpC gene (Met13Ile, Gly18Ser, Gly20Ala, Ala31Val, and Ala49Gly) were identified. In silico prediction modeling indicated that the atpC gene mutations corresponded to alterations in the transmembrane region of the ATPase, leading to a higher hydrophobicity profile in α-helix 1 and to a lower hydrophobicity profile in α-helix 2.

Antimicrobial susceptibility and genetic diversity of Streptococcus agalactiae recovered from newborns and pregnant women in Brazil.

BACKGROUND: Streptococcus agalactiae is known to be the major cause of neonatal infections and also causes complications during pregnancy. METHODS: One hundred and six strains of Streptococcus agalactiae recovered from clinical specimens of newborns (n = 18) and pregnant women (n = 88) were submitted to antimicrobial susceptibility testing and investigation of genetic determinants of macrolide resistance, capsular type, and virulence factors. Genetic diversity was evaluated by pulsed-field gel electrophoresis (PFGE) analysis. RESULTS: Strains were susceptible to ceftriaxone, levofloxacin, penicillin G, and vancomycin and resistant to tetracycline (85.8%) and erythromycin (4.7%). Erythromycin-resistant strains presented iMLSB phenotype, harbored the ermA gene, and were closely related by PFGE. Both bac and bca genes were found in low frequencies. PFGE analysis yielded 11 DNA restriction profiles among 35 selected isolates. The major clonal group, designated as A, was composed predominantly of strains belonging to capsular type Ia. Clonal group B was composed predominantly of strains with capsular type V, including all erythromycin-resistant isolates. CONCLUSIONS: Although low levels of erythromycin resistance have been observed, this is a fact of concern because this phenotype also confers resistance to clindamycin, an alternative agent for intrapartum prophylaxis. Despite the diversity of capsular types, Ia and V were among the most common and were significantly associated with distinct clonal groups. In a few cases, different capsular types were clustered into a single clonal group, which may be related to capsular switching.

Identification of human papillomavirus type 53 L1, E6 and E7 variants in isolates from Brazilian women.

Human papillomavirus type 53 (HPV 53), which belongs to genus Alpha, species A6, has spread among women worldwide. Although it is classified as a probably high risk type, the association between HPV 53 and the development of neoplastic cervical disease is unclear, and HPV 53 is known to be genomically diverse. We investigated 15 cases of HPV 53 genital infection in women living in the state of Rio de Janeiro that were not associated with severe intraepithelial cervical neoplasia. To trace HPV 53 variants in this geographic area, we characterized the L1, E6 and E7 genes from these isolates, and undertook a phylogenetic analysis based on multiple alignment of their L1 sequences. After amplification and sequence analysis, we identified seven different L1-E6-E7 variants and a L1 co-infected isolate, which taken together had base pair changes at 29 different positions. The co-infected sample presented overlapped peaks at two positions. We also detected two new E6 genomic variants. Several base pair changes in the E6 region resulted in amino acid changes, three of which were non-conservative. The E7 gene was the most conserved sequence among those studied; in contrast, the E6 sequence reached a maximum difference of 2.79%. None of the HPV 53 isolates corresponded to the reference type. Dichotomical branching characteristic of HPV 53 was observed in all of the trees constructed, as well as in the concatenated phylogenetic tree. Probably, these variants pointing to evolutionary process, but they not appear to keep an increasing of pathogenesis Despite the limited number of samples analyzed in our work, we noticed that the same variant was found in more than one woman. Therefore, it is possible that such variants have been circulating in the female population in the state of Rio de Janeiro for a longer time or that due to host or genetic viral factors, these variants can spread more rapidly than others.

Molecular characterization of quinolone-resistant Neisseria gonorrhoeae isolates from Brazil.

Despite the rapid spread of antibiotic resistance among gonococci worldwide, limited reports are available from Brazilian locations. In the present study, 25 quinolone-resistant Neisseria gonorrhoeae (QRNG) strains isolated in Rio de Janeiro, Brazil, were characterized by phenotypic and molecular methods, including analysis of mutations in the gyrA and parC genes. They represented 16.5% of the N. gonorrhoeae isolates obtained during a survey performed from 2006 to 2010. A trend for increasing resistance to ciprofloxacin was observed in the period investigated. The most prevalent pattern of mutation observed among QRNG isolates, Ser-91 to Phe and Asp-95 to Gly in gyrA and Ser-87 to Arg in parC, was detected in 40% of the isolates exhibiting MICs ranging from 4 to >32 µg/ml. Rare types of mutations were found in the gyrA gene (Gln-102 to His [12%] and Asp-95 to Tyr [4%]) and in the parC gene (Ser-88 to Thr [4%]). The genetic relationship of the QRNG isolates, evaluated by pulsed-field gel electrophoresis, suggested that the increase in the frequencies of the QRNG isolates in Rio de Janeiro, Brazil, may have arisen as a result of simultaneous spread of two clonal groups. The results also indicate that fluoroquinolones may no longer be used as first line antibiotics for the treatment of gonorrhea in Rio de Janeiro, and that programs for antimicrobial susceptibility surveillance of N. gonorrhoeae should also be implemented in other regions of Brazil.

Antimicrobial resistance profiles and genetic characterisation of macrolide resistant isolates of Streptococcus agalactiae.

In this study, 100 clinical isolates of Streptococcus agalactiae recovered from genitourinary tract specimens of non-pregnant individuals living in Rio de Janeiro were submitted for antimicrobial susceptibility testing, detection of macrolide resistance genes and evaluation of the genetic diversity of erythromycin-resistant isolates. By agar diffusion method, all isolates were susceptible to ceftazidime, penicillin and vancomycin. Isolates were resistant to levofloxacin (1%), clindamycin (5%), erythromycin (11%) and tetracycline (83%) and were intermediated to erythromycin (4%) and tetracycline (6%). Erythromycin-resistant and intermediated isolates presented the following phenotypes: M (n = 3), constitutive macrolide-lincosamide-streptogramin B (MLS B, n = 5) and inductive MLS B (n = 7). Determinants of macrolide resistance genes, erm and mef, were detected in isolates presenting MLS B and M phenotypes, respectively. Randomly amplified polymorphic DNA profiles of erythromycin-resistant isolates were clustered into two major groups of similarity.

Emergence of the vanA genotype among Enterococcus gallinarum isolates colonising the intestinal tract of patients in a university hospital in Rio de Janeiro, Brazil.

We describe the characteristics of seven unusual isolates of vancomycin-resistant enterococci (VRE) carrying both the vanC1 and vanA genes that were detected during a 3-month survey carried out to investigate the occurrence of faecal carriage of VRE. The isolates were identified as Enterococcus gallinarum and showed high-level resistance to both vancomycin and teicoplanin (minimum inhibitory concentrations >256 microg/mL and 64-96 microg/mL, respectively). All seven isolates were also resistant to chloramphenicol, erythromycin and high levels of gentamicin, and showed intermediate susceptibility to both quinolones tested (ciprofloxacin and norfloxacin). Susceptibility to fosfomycin, rifampicin and tetracycline varied among isolates. High-level resistance to gentamicin was associated with the aac(6')-aph(2'') gene, and resistance to erythromycin was associated with the erm(B) gene. The seven vanA-carrying E. gallinarum isolates had similar pulsed-field gel electrophoresis (PFGE) profiles. The emergence of multiple antimicrobial resistance, including high-level resistance to glycopeptides, among E. gallinarum points out the need to increase awareness for detection and proper characterisation of these microorganisms, as they may represent potential reservoirs of transmissible, clinically significant resistance genes in nosocomial settings.