Diversity of metallo-β-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region

Abstract

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 Tn 125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In 86 . 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.

Distinct Mechanisms of Dissemination of NDM-1 Metallo-β-Lactamase in Acinetobacter Species in Argentina

“…Although reports of bla NDM in Latin America are limited, sentinel investigations have described the presence of Tn125 in Acinetobacter spp. (6,(15)(16)(17). An ST25 A. baumannii strain from a patient with an abdominal infection in Honduras was determined to have Tn125 on a plasmid (18), but this plasmid was not present in the ST25 strains analyzed here.…”

The Spread of NDM-1 and NDM-7-Producing Klebsiella pneumoniae Is Driven by Multiclonal Expansion of High-Risk Clones in Healthcare Institutions in the State of Pará, Brazilian Amazon Region

“…In Brazil, KPC has become endemic and widely disseminated among K. pneumoniae from hospitals in all Brazilian regions [ 5 , 14 , 17 , 20 , 21 , 27 , 28 , 29 , 30 ]. Since 2013, NDM-producing isolates have been reported in different Brazilian regions and associated with a wide variety of bacterial species, including Escherichia coli , Acinetobacter baumannii , A. nosocomialis , A. pittii, Enterobacter cloacae, Enterobacter hormaechei, and K. pneumoniae [ 12 , 15 , 16 , 31 , 32 , 33 , 34 , 35 ]. Recently, Silva et al [ 16 ], in a study evaluating 81 bacterial isolates from different regions, demonstrated that K. pneumoniae is responsible for the widespread of this carbapenemase in Brazilian hospitals, confirming more efficient dissemination compared with the bla KPC variant.…”

Acinetobacter baumannii resistente aos carbapenêmicos em Minas Gerais: epidemiologia hospitalar, multirresistência e disseminação de clones de alto risco

“…nosocomialis e A. baumannii (PILLONETTO et al, 2014;CHAGAS et al, 2015;PAGANO et al, 2015;BRASILIENSE et al, 2019 (HIGGINS et al, 2013). No Brasil, OXA-23 é a principal oxacilinase responsável pela resistência aos carbapenêmicos em amostras hospitalares (DALLA-COSTA et al, 2003;CARVALHO et al, 2009;MARTINS et al, 2009;MOSTACHIO et al, 2009;ROYER et al, 2015).…”

“…Curiosamente, as duas cepas foram isoladas em 2016 e os pacientes tinham doenças neurológicas, no entanto, as cepas estavam geograficamente distantes a 2.330,4 km (BRASILIENSE et al, 2019). Outro plasmídeo idêntico foi relatado em A. baumannii nos EUA, em 2018, sugerindo a circulação desse plasmídeo no continente americano contendo uma variante do Tn125 em Acinetobacter sp., uma vez que não foi encontrado no GenBank plasmídeo semelhante em isolados da Europa e somente um na Ásia.…”

“…Em nosso estudo, conforme mencionado anteriormente, a análise do MLST revelou que Ab17 pertence a um novo ST, ST1465/CC216. Estudos anteriores mostraram que esse plasmídeo com uma variante do Tn125 se disseminou em Acinetobacter sp., a partir de diferentes STs: ST71/CC410, ST239 e ST464 (ROJAS et al, 2016;MARQUEZ-ORTIZ et al, 2017;BRASILIENSE et al, 2019). Wu e colaboradores (2019) mostraram que espécies de Acinetobacter são distribuídas em múltiplos STs, sugerindo heterogeneidade de blaNDM-1 entre espécies bacterianas.…”