Low Prevalence of bla OXA-143 in Private Hospitals in Brazil

The acquired carbapenem-hydrolyzing oxacillinase (OXA) OXA-143 has thus far been detected only in Acinetobacter baumannii isolates from Brazil. The aim of this study was to characterize three OXA-143 variants: OXA-231 and OXA-253 from carbapenemresistant A. baumannii isolates and OXA-255 in a carbapenem-susceptible Acinetobacter pittii isolate originating from Brazil, Honduras, and the United States, respectively. The 5= rapid amplification of cDNA ends (RACE) technique identified the same transcription initiation site for all bla OXA-143-like genes and revealed differences in the putative promoter regions. However, all cloned OXA-143 variants conferred carbapenem resistance on A. baumannii ATCC 17978 and OXA-255 conferred carbapenem resistance on A. pittii SH024, which was correlated with bla OXA-255 gene expression. This is the first description of OXA-143-like outside A. baumannii. Detection of OXA-143-like in the United States and Honduras indicates its dissemination through the American continent.

Section: Resultsmentioning

confidence: 88%

Characterization of bla _OXA-143 Variants in Acinetobacter baumannii and Acinetobacter pittii

Zander

Bonnin

Seifert

et al. 2014

“…Here, we report the identification of a novel class A carbapenemase, BKC-1, in K. pneumoniae clinical isolates belonging to a single clone that spread between two hospitals of the city of São Paulo. Patient-to-patient transmission might be one of the reasons for justifying the dissemination of BKC-producing K. pneumoniae, since interhospital spread of resistant Gram-negative clones has frequently been reported in Brazil (26)(27)(28).…”

Section: Discussionmentioning

confidence: 99%

Characterization of BKC-1 Class A Carbapenemase from Klebsiella pneumoniae Clinical Isolates in Brazil

Nicoletti

Marcondes

Martins

et al. 2015

Three Klebsiella pneumoniae clinical isolates demonstrating carbapenem resistance were recovered from different patients hospitalized at two medical centers in São Paulo, Brazil. Resistance to all ␤-lactams, quinolones, and some aminoglycosides was observed for these isolates that were susceptible to polymyxin B. Carbapenem hydrolysis, which was inhibited by clavulanic acid, was observed for all K. pneumoniae isolates that belonged to the same pulsed-field gel electrophoresis (PFGE) type and a novel sequence type (ST), ST1781 (clonal complex 442 [CC442]). A 10-kb nonconjugative incompatibility group Q (IncQ) plasmid, denominated p60136, was transferred to Escherichia coli strain TOP10 cells by electroporation. The full sequencing of p60136 showed that it was composed of a mobilization system, ISKpn23, the phosphotransferase aph3A-VI, and a 941-bp open reading frame (ORF) that codified a 313-amino acid protein. This ORF was named bla BKC-1 . Brazilian Klebsiella carbapenemase-1 (BKC-1) showed a pI of 6.0 and possessed the highest identity (63%) with a ␤-lactamase of Sinorhizobium meliloti, an environmental bacterium. Hydrolysis studies demonstrated that purified BKC-1 not only hydrolyzed carbapenems but also penicillins, cephalosporins, and monobactams. However, the carbapenems were less efficiently hydrolyzed due to their very low k cat values (0.0016 to 0.031 s ؊1 ). In fact, oxacillin was the best substrate for BKC-1 (k cat /K m , 53,522.6 mM ؊1 s ؊1 ). Here, we report a new class A carbapenemase, confirming the diversity and rapid evolution of ␤-lactamases in K. pneumoniae clinical isolates.

“…This variant of the OXA-143-like carbapenemase belongs to the Ambler class D of ␤-lactamases (5), which has previously been the subject of studies discussing its incidence in Brazil. So far, however, the bla OXA-143 gene has only been reported for samples from the states of São Paulo and Rio de Janeiro, over 1,800 km to the south of Recife (2,(6)(7)(8).…”

mentioning

confidence: 99%

High Frequency of OXA-253-Producing Acinetobacter baumannii in Different Hospitals in Recife, Brazil

Cavalcanti

Mendes-Marques

Vasconcelos

et al. 2017

Here, we report the isolation of 31 Acinetobacter baumannii strains producing OXA-253 in a single large Brazilian city. These strains belonged to five different sequence types (STs), including 4 STs not previously associated with bla . In all strains, the bla OXA-253 gene was located in a plasmid within a genetic environment similar to what was found previously in Brazil and Italy. The reported data emphasize the successful transmission of the bla OXA-253 gene through a large area and the tendency for this resistance determinant to remain in the A. baumannii population.KEYWORDS Acinetobacter, MLST, antibiotic resistance, genome analysis, oxacillinase A cinetobacter baumannii is an opportunistic Gram-negative pathogen responsible for a large number of outbreaks of hospital-acquired infections. This bacterium has been linked with serious infections affecting mainly debilitated patients in intensive care units (1), and it can become resistant to a wide range of antibiotics, leading to serious impediments to treatment. Carbapenems, such as imipenem and meropenem, have been often used as drugs of last resort, but outbreaks of carbapenem-resistant A. baumannii have been reported in several countries, including Brazil (2).Resistance to carbapenems in A. baumannii may be due to various mechanisms, including the loss of outer membrane protein (OMP), overexpression of efflux pumps, or through alterations in the penicillin-binding protein (3). An increase in reported carbapenem resistance by A. baumannii isolates, however, has been mostly attributed to yet another mechanism, the production of carbapenemases, such as those belonging to the class D OXA type (4).Here, we report OXA-253-producing A. baumannii strains isolated from different hospitals localized within the city of Recife, state of Pernambuco, in northeastern Brazil. This variant of the OXA-143-like carbapenemase belongs to the Ambler class D of ␤-lactamases (5), which has previously been the subject of studies discussing its incidence in Brazil. So far, however, the bla OXA-143 gene has only been reported for samples from the states of São Paulo and Rio de Janeiro, over 1,800 km to the south of Recife (2, 6-8).Identification of the OXA-253-producing strains occurred after sequencing of the genomes of 45 A. baumannii strains displaying an extensively drug-resistant (XDR) phenotype and isolated from different individuals hospitalized in five public hospitals in Recife between 2010 and 2014. These strains were considered resistant to the two carbapenems tested (imipenem and meropenem) according to the Brazilian Committee on Antimicrobial Susceptibility Testing (BrCAST) guidelines, using the broth microdilution method. A detailed report of the whole-genomic data analysis, in the context of resistance and virulence characteristics, will be provided in future publications. Analysis of the sequencing data led to identification in 31 strains of the recently described class D ␤-lactamase bla OXA-253 (9). According to a multilocus sequence typing (MLST) analysis...