Unexplored Genetic Diversity of Multidrug- and Extremely Drug-Resistant Acinetobacter baumannii Isolates from Tertiary Hospitals in Honduras

Microb Drug Resist. 2019 Jun;25(5):690-695. doi: 10.1089/mdr.2018.0311. Epub 2019 Jan 3.

Abstract

Although Acinetobacter baumannii has become one of the most important nosocomial pathogens worldwide, very little is known about the genetic identity of isolates from less developed countries in Latin America. To alleviate this, we sequenced the genomes of 16 A. baumannii isolates from Honduras. Whole-genome sequencing was conducted on 16 isolates from five Honduran Hospitals. With the sequences of these Honduran isolates and other 42 publically available genomes, a maximum likelihood phylogeny was constructed to establish the relationship between the Honduran isolates and those belonging to the International Clones (ICs). In addition, sequence type (ST) assignation was conducted by the PubMLST, and antibiotic resistance genes were identified using ResFinder. The Honduran isolates are highly diverse and contain new allele combinations under the Bartual multilocus sequence typing scheme. The most common STs were STB447/STP10 and STB758/STP156. Furthermore, none of these isolates belongs to clonal complexes related to the ICs. Antibiotic susceptibility profiles of these isolates showed that they are multidrug resistant (MDR) or extensively drug resistant (XDR). In addition, the Honduran isolates had genes involved in resistance to seven antibiotic families. For instance, several blaOXA alleles were found, including blaOXA-23 and a gene encoding the metallo-beta-lactamase NDM-1. Notably, nine of the Honduran isolates have antibiotic resistance genes to three or more antibiotic families. In summary, in this study, we unveiled an untapped source of genetic diversity of MDR and XDR isolates; notably, these isolates did not belong to the well-known ICs.

Keywords: International clonal complex; NDM-1; OXA-23; antibiotic resistance genes.

MeSH terms

  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / epidemiology*
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / classification
  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Clone Cells
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Epidemiological Monitoring
  • Gene Expression
  • Genes, Bacterial*
  • Genetic Variation
  • Genome, Bacterial*
  • Honduras / epidemiology
  • Humans
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Phylogeny
  • Plasmids / chemistry
  • Plasmids / metabolism
  • Tertiary Care Centers
  • Whole Genome Sequencing
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases