ABSTRACT Due to the emergence of multi-drug resistant bacteria, and the evident limitation in therapeutic options, alternatives to combat bacterial infections have been sought. One of these is phage therapy, which is the use of bacterial viruses to kill pathogenic bacteria responsible for the infection. These viruses called bacteriophages are very abundant organisms in the world and are harmless to humans. There are several advantages in using phage therapy, especially against multi-drug resistant pathogens, which tend to be dominated by individual strains. The advantages include fewer collateral effects such as lower disturbance of gut microbiota and less antimicrobials consumption, which itself leads to reducing antibiotic resistance rates. Unfortunately, few clinical studies have been initiated in Brazil and this area is little explored in our country. This manuscript describes clinical evidence of successful phage utilization on pathogens considered a threat in Brazil, highlighting the benefits of a possible phage utilization as an important tool to combat antimicrobial resistance in our country.

ABSTRACT The Choosing Wisely Initiative aims to collect statements from medical societies all over the world on medical interventions that result in no benefit to patients, with the potential to cause harm. In this article we present the views of the Diagnostic Laboratory Group at the Brazilian Society of Infectious Diseases (SBI). Ten experts from SBI were asked to list 10 diagnostic tests that were perceived as unnecessary in the field of infectious diseases. After voting for the more relevant topics, a questionnaire was sent to all SBI members, in order to select for the most important items. A total of 482 votes were obtained, and the top 10 results are shown in this manuscript. The Choosing Wisely statements of SBI should facilitate clinical practice by optimizing the use of diagnostic resources in the field of infectious diseases.

BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

OBJECTIVES The emergence of 16S rRNA methyltranferases (16 RMTAses) has jeopardised the clinical use of aminoglycosides. RmtB is one of the most frequently reported in Gram-negatives worldwide. In this study, we aimed to estimate the frequency of 16S RMTAses encoding genes in Enterobacteriaceae isolated in a three-month period from a tertiary Brazilian hospital. METHODS All Gram-negatives classified as resistant to amikacin, gentamicin, and tobramycin by agar screening were selected for analysis. The presence of 16SRMTases encoding genes was verified by polymerase chain reaction (PCR). Antimicrobial susceptible profile was determined by broth microdilution. The genetic relationship among these isolates was accessed by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Selected RmtB-producing isolates were characterised by whole genome sequencing (WGS) analysis. RESULTS Twenty-two of 1,052 (2.1%) Enterobacteriaceae were detected as producers of RmtB-1 [Klebsiella pneumoniae (n = 21) and Proteus mirabilis (n = 1)]. blaKPC-2 was identified among 20 RmtB-1-producing K. pneumoniae isolates that exhibited an identical PFGE and MLST (ST258) patterns. Two K. pneumoniae isolates, the A64216 (not harboring bla KPC-2), A64477 (harboring bla KPC-2) and one P. mirabilis isolate (A64421) were selected for WGS. rmtB-1 and bla KPC-2 genes were carried by distinct plasmids. While a plasmid belonging to the IncFIIk group harbored rmtB-1 in K. pneumoniae, this gene was carried by a non-typable plasmid in P. mirabilis. In the three analysed plasmids, rmtB-1 was inserted on a transposon, downstream a Tn2. CONCLUSION Our findings suggested that the rmtB-1 was harbored by plasmids distinct from those previously reported in Bolivia and China. It suggests that multiple mobilization events might have occurred in South America.

Abstract Introduction: Latin America is a large and diverse region, comprising more than 600 million inhabitants and one million physicians in over 20 countries. Resistance to antibacterial drugs is particularly important in the region. This paper describes the design, implementation and results of an international bi-lingual (Spanish and Portuguese) online continuing interprofessional interactive educational program on hospital-acquired infections and antimicrobial resistance for Latin America, supported by the American Society for Microbiology. Methods: Participation, satisfaction and knowledge gain (through pre and post tests) were used. Moreover, commitment to change statements were requested from participants at the end of the course and three months later. Results: There were 1169 participants from 19 Latin American countries who registered: 57% were physicians and 43% were other health care professionals. Of those, 1126 participated in the course, 46% received a certificate of completion and 54% a certificate of participation. There was a significant increase in knowledge between before and after the course. Of 535 participants who took both tests, the grade increased from 59 to 81%. Commitments to change were aligned with course objectives. Discussion: Implementation of this educational program showed the feasibility of a continent-wide interprofessional massive course on hospital acquired-infections in Latin America, in the two main languages spoken in the region. Next steps included a new edition of this course and a "New Challenges" course on hospital-acquired infections, which were successfully implemented in the second semester of 2015 by the same institutions.

OBJECTIVE: To establish a resistance (R) surveillance program monitoring antimicrobial susceptibility patterns in Latin America (LATAM; Argentina [ARG], Brazil [BRA], Chile, Colombia [CBA], Costa Rica, Ecuador [ECU], Guatemala [GUA], Mexico [MEX], Panama [PAN], Peru, and Venezuela [VEN]). METHODS: In 2011, 4979 organisms were collected from 11 nations (20 laboratories) for susceptibility testing in a central laboratory design. Antimicrobials were tested by CLSI methods and results interpreted by CLSI and EUCAST breakpoints. Most common Gram-positive (Staphylococcus aureus [SA, 921], other staphylococci [CoNS; 299], enterococci [218], Streptococcus pneumoniae [SPN; 182], β-haemolytic streptococci [115]) and Gram-negative (E. coli [EC; 644], Klebsiella spp. [KSP; 517], Enterobacters [272], Pseudomonas aeruginosa [PSA; 586], Acinetobacters [ACB; 494]) pathogens were analyzed against linezolid (LZD), vancomycin (VAN), tigecycline (TIG), colistin (COL), cefoperazone/sulbactam (C/S), and amikacin (AMK). RESULTS: MRSA rates varied from 29% (CBA, BRA) to 79% (Peru); but LZD (MIC90, 2 mg/L), TIG (MIC90, 0.12mg/L) and VAN (MIC90, 1mg/L) covered all strains. Enterococci showed a 14% VRE rate, highest in BRA and MEX; all inhibited by TIG and daptomycin, but not LZD (three non-susceptible with G2576T mutations or cfr). Penicillin-R among SPN and viridans streptococci was 51.6 and 41.1%, respectively. LZD overall R against Gram-positives was 0.3%. High ESBL rates were observed in EC (54-71%) and KSP (>50%) from GUA, MEX and Peru, and six nations, respectively. Carbapenem-R in KSP was 9%, highest rates associated with KPC in BRA, CBA, ECU, PAN and VEN; also a NDM-1 in KSP from CBA. AMK, TIG, C/S and carbapenems were the broadest-spectrum agents tested against Enterobacteriaceae. Only COL inhibited >90% of PSA; COL and TIG (<2 mg/L) covered >85% of ACB. CONCLUSIONS: LATAM nations demonstrated variable levels of antimicrobial R especially among Enterobacteriaceae (β-lactamase-mediated), PSA and ACB. MRSA (48%), VRE (14%) and multidrug-R SPN were also regional therapeutic challenges.

In Brazil, the presence of plasmid-mediated AmpC (pAmpC)-producing isolates has been sporadically reported. We evaluated the frequency of pAmpC among 133 Enterobacteriaceae clinical isolates. The blaCMY-2-like gene was detected in a single Klebsiella pneumoniae isolate. In our study, the pAmpC frequency was very low as previously reported.

The emergence of KPC-2 producing K. pneumoniae in hospitalized patients at the intensive care unit (ICU) of a teaching hospital located in the city of João Pessoa, Paraíba, Brazil, is reported. Seven carbapenem-resistant K. pneumoniae recovered from different body sites of infection were analyzed. Most isolates showed a multidrug-resistance phenotype. Genotypic analysis demonstrated the presence of two genotypes, with the predominance of genotype A, which belongs to ST 437. These isolates also carry the encoding genes of five other betalactamases.

Ceftobiprole is a broad-spectrum cephalosporin with potent activity against staphylococci, including those resistant to oxacillin, as well as against most Gram-negative bacilli including Pseudomonas aeruginosa. In this study, the in vitro activity of ceftobiprole and comparator agents was tested against bacterial isolates recently collected from Brazilian private hospitals. A total of 336 unique bacterial isolates were collected from hospitalized patients between February 2008 and August 2009. Each hospital was asked to submit 100 single bacterial isolates responsible for causing blood, lower respiratory tract or skin and soft tissue infections. Bacterial identification was confirmed and antimicrobial susceptibility testing was performed using CLSI microdilution method at a central laboratory. The CLSI M100-S21 (2011) was used for interpretation of the antimicrobial susceptibility results. Among the 336 pathogens collected, 255 (75.9%) were Gram-negative bacilli and 81 (24.1%) were Gram-positive cocci. Although ceftobiprole MIC50 values for oxacillin resistant strains were two-fold higher than for methicillin susceptible S. aureus, ceftobiprole inhibited 100% of tested S. aureus at MICs < 4 µg/mL. Polymyxin B was the only agent to show potent activity against Acinetobacter spp. (MIC50/90, 0.5/1 µg/mL), and P. aeruginosa (MIC50/90, 1/2 µg/mL). Resistance to broad-spectrum cephalosporins varied from 55.3-68.5% and 14.3-28.5% among E. coli and Klebsiella spp. isolates, respectively; with ceftobiprole MIC50 > 6 µg/mL for both species. Our results showed that ceftobiprole has potent activity against staphylococci and E. faecalis, which was superior to that of vancomycin. Our data also indicates that ceftobiprole demonstrated potency comparable to that of cefepime and ceftazidime against key Gram-negative species.

We report the antimicrobial susceptibility patterns of the most frequently isolated Gram-positive bacteria in the Brazilian hospitals participating in the SENTRYAntimicrobial Surveillance Program. The strains were consecutively collected (one per patient) between January 2005 and September 2008 and susceptibility tested by reference broth microdilution methods at the JMI Laboratories (North Liberty, Iowa, USA). A total of 3,907 Gram-positive cocci were analyzed. The Gram-positive organisms most frequently isolated from bloodstream infections were Staphylococcus aureus (2,218 strains; 20.2% of total), coagulase-negative staphylococci (CoNS; 812 strains [14.7%]), and Enterococcus spp. (754 strains; 5.0%). S. aureus ranked first (28.1%) and Enterococcus faecalis ranked 7th (4.5%) among cases of skin and soft tissue infections. S. aureus was also the second most frequently isolated pathogen from patients with lower respiratory tract infections (24.9% of cases) after Pseudomonas aeruginosa (30.5%). Resistance to oxacillin was observed in 31.0% of S. aureus and the vast majority of oxacillin-resistant (MRSA) strains were also resistant to clindamycin, ciprofloxacin and levofloxacin. Vancomycin, linezolid and daptomycin were all very active against S. aureus strains tested (>99.9-100.0% susceptible), but daptomycin (MIC50, 0.25 g/mL and MIC90, 0.5 g/mL) was four- to eight-fold more potent than vancomycin (MIC50 and MIC90 of 1 g/mL) and linezolid (MIC50, 1 g/mL and MIC90, 2 g/mL). Vancomycin resistance increased significantly among enterococci during the study period, but it was restrict to only one medical center until 2007 and emerged in a second medical center in 2008. Daptomycin was the most active antimicrobial tested against enterococci in general (100.0% susceptible), followed by linezolid (99.9% susceptible), ampicillin (87.4%) and vancomycin (84.6%). In conclusion, daptomycin and linezolid showed excellent in vitro activity against contemporary Gram-positive organisms (3,907) collected in Brazilian hospitals monitored by the SENTRY Program, including MRSA, vancomycin-resistant enterococci (VRE) and other multidrugresistant organisms. Although vancomycin resistance rates in Brazil appears to be relatively low compared to those reported in the USA, VRE has emerged and rapidly disseminated in some Brazilian medical centers.

Increasing quinolone resistance has been reported worldwide, mainly among clinical isolates of Escherichia coli. The objectives of this study were to determine the susceptibility profile, the genetic relatedness, and the prevalence of the qnr gene among ciprofloxacin-resistant Escherichia coli isolated from distinct Brazilian hospitals. A total of 144 ciprofloxacin-resistant Escherichia coli were isolated from 17 Brazilian hospitals between January/2002 and June/2003. The antimicrobial susceptibility testing was performed by microdilution according to NCCLS. The presence of the qnr gene was initially screened by colony blotting, and then confirmed by PCR followed by DNA sequencing. Ninety-five urinary ciprofloxacin-resistant Escherichia coli were further selected for molecular typing by pulsed-field gel electrophoresis (PFGE). Imipenem and meropenem showed the highest susceptibility rates (100.0% for both compounds) followed by amikacin (91.0%) and piperacillin/tazobactan (84.8%). A single ciprofloxacin-resistant Escherichia coli isolate was positive for qnr among the 144 ciprofloxacin-resistant Escherichia coli. Forty-six PFGE patterns were observed among the 95 ciprofloxacin-resistant Escherichia coli type. This study shows that therapeutic options are limited for treatment of ciprofloxacin-resistant Escherichia coli due to the presence of additional mechanisms of antimicrobial resistance, such as ESBL production. The qnr gene was uncommon among ciprofloxacin-resistant Escherichia coli clinical isolates, but its identification might indicate the emergence of this mechanism of quinolone resistance in Brazil. The great genomic variability found among the ciprofloxacin-resistant Escherichia coli highlights the importance of the appropriate use of quinolone to restrict the selection of resistant isolates.

Emerging resistance phenotypes and antimicrobial resistance rates among pathogens recovered from community-acquired urinary tract infections (CA-UTI) is an increasing problem in specific regions, limiting therapeutic options. As part of the SENTRY Antimicrobial Surveillance Program, a total of 611 isolates were collected in 2003 from patients with CA-UTI presenting at Latin American medical centers. Each strain was tested in a central laboratory using Clinical Laboratory Standard Institute (CLSI) broth microdilution methods with appropriate controls. Escherichia coli was the leading pathogen (66%), followed by Klebsiella spp. (7%), Proteus mirabilis (6.4%), Enterococcus spp. (5.6%), and Pseudomonas aeruginosa (4.6%). Surprisingly high resistance rates were recorded for E. coli against first-line orally administered agents for CA-UTI, such as ampicillin (53.6%), TMP/SMX (40.4%), ciprofloxacin (21.6%), and gatifloxacin (17.1%). Decreased susceptibility rates to TMP/SMX and ciprofloxacin were also documented for Klebsiella spp. (79.1 and 81.4%, respectively), and P. mirabilis (71.8 and 84.6%, respectively). For Enterococcus spp., susceptibility rates to ampicillin, chloramphenicol, ciprofloxacin, and vancomycin were 88.2, 85.3, 55.9, and 97.1%, respectively. High-level resistance to gentamicin was detected in 24% of Enterococcus spp. Bacteria isolated from patients with CA-UTI in Latin America showed limited susceptibility to orally administered antimicrobials, especially for TMP/SMX and fluoroquinolones. Our results highlight the need for developing specific CA-UTI guidelines in geographic regions where elevated resistance to new and old compounds may influence prescribing decisions.

The in vitro activity of tigecycline (former GAR-936), a new semisynthetic tetracycline, was evaluated in comparison with tetracycline and other antimicrobial agents. MATERIAL AND METHODS: A total of 1,326 contemporary clinical isolates collected from the Latin American region were collected in 2000-2002 period and tested with microdilution broth according to the CLSI guidelines. The bacterial pathogens evaluated included Staphylococcus aureus (505), Streptococcus pneumoniae (269), coagulase-negative staphylococci (CoNS; 227), Haemophilus influenzae (129), Enterococcus spp. (80), Moraxella catarrhalis (54), beta-haemolytic streptococci (28), viridans group streptococci (26), and Neisseria meningitidis (8) RESULTS:Tigecycline demonstrated excellent activity against all Gram-positive cocci, with 90% of penicillin-resistant S. pneumoniae strains being inhibited at 0.12 µg/mL, while the same isolates had an MIC90 of > 16 µg/mL for tetracycline. All Enterococcus spp. were inhibited at 0.25 µg/mL of tigecycline. Tigecycline (MIC50, 0.25 µg/mL) was eight-fold more potent than minocycline (MIC50, 2 µg/mL) against oxacillin-resistant S. aureus (ORSA); all ORSA were inhibited at < 2 µg/mL of tigecycline. Tigecycline demonstrated excellent activity (MIC50, 0.5 µg/mL) against CoNS with reduced susceptibility to teicoplanin (MIC, 16 µg/mL). Tigecycline also showed high potency against respiratory pathogens such as M. catarrhalis (MIC50, 0.12 µg/mL) and H. influenzae (MIC50, 0.5 µg/mL). No tigecycline resistant isolates were detected when the proposed susceptible breakpoints (< 4 µg/mL) was applied. CONCLUSIONS: This results indicate that tigecycline has potent in vitro activity against clinically important pathogenic bacteria, including Gram-positive isolates resistant to both tetracycline and minocycline.

The antimicrobial susceptibility of 176 unusual non-fermentative gram-negative bacilli (NF-GNB) collected from Latin America region through the SENTRY Program between 1997 and 2002 was evaluated by broth microdilution according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. Nearly 74% of the NF-BGN belonged to the following genera/species: Burkholderia spp. (83), Achromobacter spp. (25), Ralstonia pickettii (16), Alcaligenes spp. (12), and Cryseobacterium spp. (12). Generally, trimethoprim/sulfamethoxazole (MIC50, < 0.5 µg/ml) was the most potent drug followed by levofloxacin (MIC50, 0.5 µg/ml), and gatifloxacin (MIC50, 1 µg/ml). The highest susceptibility rates were observed for levofloxacin (78.3%), gatifloxacin (75.6%), and meropenem (72.6%). Ceftazidime (MIC50, 4 µg/ml; 83.1% susceptible) was the most active beta-lactam against B. cepacia. Against Achromobacter spp. isolates, meropenem (MIC50, 0.25 µg/ml; 88% susceptible) was more active than imipenem (MIC50, 2 µg/ml). Cefepime (MIC50, 2 µg/ml; 81.3% susceptible), and imipenem (MIC50, 2 µg/ml; 81.3% susceptible) were more active than ceftazidime (MIC50, >16 µg/ml; 18.8% susceptible) and meropenem (MIC50, 8 µg/ml; 50% susceptible) against Ralstonia pickettii. Since selection of the most appropriate antimicrobial agents for testing and reporting has not been established by the NCCLS for many of NF-GNB species, results from large multicenter studies may help to guide the best empiric therapy.