Carbapenemase-producing Enterobacteriaceae may exhibit susceptibility to carbapenems. For this reason with the recent spread of NDM-1 among Enterobacteriaceae, the phenotypic detection of metallo-beta-lactamase (ML)-producing has been recommended by Brazilian Agency of Sanitary Surveillance (ANVISA). 1 In 2013, two pan drug-resistant Klebsiella pneumoniae (KPN1 and KPN2) isolates were recovered from urine (cystostomy) of a 75-year-old male patient hospitalized in a tertiary teaching hospital in Florianópolis, Santa Catarina, Brazil. Both isolates were phenotypically identified as ML producers by ethylenediamine tetraacetic acid (EDTA)/double-disk synergy test (DDST) and forwarded to our laboratory for further characterization. Identification of both isolates as K. pneumoniae was confirmed by MALDI-TOF MS (Bruker Daltonics, Germany), according to the manufacturer's recommendations. Both isolates showed an identical pattern by ERIC-PCR. The minimal inhibitory concentrations (MICs) for selected antimicrobial agents were determined by broth microdilution according to Clinical and Laboratory Standards Institute -CLSI. The MICs were interpreted according to the CLSI guidelines, 2 except for tigecycline, which interpretation was performed according to the European Committee on Antimicrobial Susceptibility Testing -EUCAST. Both isolates were fully resistant to all broad-spectrum cephalosporins, aztreonam, gentamicin, fluoroquinolones, meropenem, ertapenem, and polymyxin B as shown in Table 1. The isolates showed intermediate resistance to imipenem and amikacin. While KPN1 was susceptible to tigecycline, KPN2 became resistant to this agent.The isolates were also screened for ESL production by disk approximation and the synergism was observed only when amoxicillin/clavulanic acid disk was tested 15 mm a part of ceftriaxone, ceftazidime and cefepime disks. The phenotypic detection of ML was carried out by the EDTA/DDST and confirmed by ertapenem hydrolysis assay using MALDI-TOF MS (Bruker Daltonics, Germany) as previously reported. 3 Although both isolates showed an increase in the inhibition zone of ceftazidime/EDTA (6 mm) and meropenem/EDTA (7 mm) disks compared to the ceftazidime and meropenem disks, respectively, hydrolysis of ertapenem was not observed, suggesting that both isolates were not ML producers.The search for -lactamase encoding genes was carried out by PCR followed by DNA sequencing of amplicons. Both K. pneumoniae isolates carried bla CTX-M-15 , and the narrow spectrum--lactamases encoding genes, bla SHV-11 , bla TEM-1 and bla OXA-1 . The presence of the plasmid mediated qnrS1 gene and a mutation Ser83Ile in gyrA were also detected, justifying the quinolone resistance exhibited by both KPN isolates. The analysis of the outer membrane proteins profile by SDS-PAGE showed that both isolates lost the major porins OmpK35 and OmpK36. Sequencing analysis of the ompk35 and ompk36 genes revealed the presence of the insertion sequence IS1 between the promoter region and the start codon of the ompK35 gene, and ...
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.
A total of 124 Neisseria gonorrhoeae isolates recovered during a 12-year period (2003-2015) from outpatients assisted at Centro de Referência e Treinamento DST/AIDS-CRT of São Paulo city, Brazil, were analysed. The following resistance rates were observed: penicillin-59.6%, ciprofloxacin-15.3%, and azithromycin-6.7%. Although reduced susceptibility to these drugs was observed since 2003, no ceftriaxone-resistant isolates were detected. Ciprofloxacin- and azithromycin non-susceptible isolates were grouped in 11 clusters. Mutations were detected in GyrA and ParC of isolates 124 and 260, and a C 2611 T substitution on 23S rRNA alleles was also observed in isolate 260. Both isolates belonged to ST1901/ST6210 (MSLT/NG-MAST schemes).
IntroductionThe emergence of antimicrobial resistance among N. gonorrhoeae isolates is a major concern worldwide. Although quinolones and macrolides are still recommended for empirical treatment of urethritis according to our national guidelines.The objective of this study was to evaluate the antimicrobial susceptibility profile of N. gonorrheae recovered from 2003 to 2015 from outpatients assisted at the Centro de Referência e Treinamento DST/AIDS-CRT Santa Cruz, São Paulo – SP.MethodsThe identification was carried out by MALDI-TOF MS. The minimal inhibitory concentrations (MIC) for penicillin, ceftriaxone, ciprofloxacin and azithromycin were determined by agar dilution method and interpreted according to CLSI (2016) clinical breakpoints, except for azithromycin, which was interpreted using EUCAST (2016). The genetic relationship of isolates presenting reduced susceptibility to ciprofloxacin was evaluated by ERIC-PCR. Hydrolysis rates towards ceftazidime and cefotaxime were evaluated by mass spectrometry.ResultsAmong the 125 n. gonorrhoeae recovered, reduced susceptibilities to penicillin, ciprofloxacin, and azithromycin were observed for 89.6% (112/125), 22.3% (21/94), and 26.4% (33/125) of the isolates. Only one isolate was resistant to ceftriaxone, with MIC of 0.5 µg/mL. Reduced susceptibilities to penicillin, ciprofloxacin and azithromycin were already observed in 2003, and increased over the years, while resistance to ceftriaxone was only observed in 2006. The ceftriaxone-resistant isolate did not present detectable hydrolysis for ceftazidime and cefotaxime, suggesting that a no enzymatic mechanism was involved.ConclusionOur data corroborates with other international series and pose in question the recommended syndromic treatment with quinolones and azithromycin. Our result suggests that ceftriaxone still remains a valuable therapeutic option for the empirical treatment of gonococcal infections in Brazil. Further analysis will be performed in order to better characterise the genetic relationship and the resistance mechanisms involved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.