Extrahuman Epidemiology of Acinetobacter baumannii in Lebanon

Abstract

The presence of Acinetobacter baumannii outside hospitals is still a controversial issue. The objective of our study was to explore the extrahospital epidemiology of A. baumannii in Lebanon. From February 2012 to October 2013, a total of 73 water samples, 51 soil samples, 37 raw cow milk samples, 50 cow meat samples, 7 raw cheese samples, and 379 animal samples were analyzed by cultural methods for the presence of A. baumannii. Species identification was performed by rpoB gene sequencing. Antibiotic susceptibility was investigated, and the A. baumannii population was studied by two genotyping approaches: multilocus sequence typing (MLST) and bla OXA-51 sequence-based typing (SBT). A. baumannii was detected in 6.9% of water samples, 2.7% of milk samples, 8.0% of meat samples, 14.3% of cheese samples, and 7.7% of animal samples. All isolates showed a susceptible phenotype against most of the antibiotics tested and lacked carbapenemase-encoding genes, except one that harbored a bla OXA-143 gene. MLST analysis revealed the presence of 36 sequence types (STs), among which 24 were novel STs reported for the first time in this study. bla OXA-51 SBT showed the presence of 34 variants, among which 21 were novel and all were isolated from animal origins. Finally, 30 isolates had new partial rpoB sequences and were considered putative new Acinetobacter species. In conclusion, animals can be a potential reservoir for A. baumannii and the dissemination of new emerging carbapenemases. The roles of the novel animal clones identified in community-acquired infections should be investigated.

Metagenomic assessment of the interplay between the environment and the genetic diversification of Acinetobacter

“…A. baumannii was over‐represented in the metagenomic datasets from host‐associated environments (chi‐square test, P < 0.0001), biofilms ( P < 0.001, same test) and soil ( P < 0.0001, same test). This fits previous observations using classical identification methods (Houang et al ., ; Vangnai and Petchkroh, ; Hamouda et al ., ; Rafei et al ., ). In the oral samples of the HMP, 86% of the Acinetobacter peptides were from A. baumannii .…”

Relatedness of wildlife and livestock avian isolates of the nosocomial pathogen Acinetobacter baumannii to lineages spread in hospitals worldwide

“…A . baumannii has only sporadically been isolated from birds so far (Ahmed et al ., ; Muller et al ., ; Zordan et al ., ; Rafei et al ., ). However, workers in hatcheries show elevated immunoprecipitation reactions to A .…”

“…baumannii and A . pittii were isolated from water, sewage and soil samples and also from various animals at a rate up to 8%, notably from cow feces (Rafei et al ., ; Al Atrouni et al ., ). Also recently, raw meat samples in Switzerland were found to be contaminated with A .…”

Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges

“…These environmental strains often harbor antibiotic resistance mechanisms, including carbapenemases and extended-spectrum ␤-lactamases (ESBLs) (3), and may thus serve as important environmental reservoirs for resistance elements that transform into clinically relevant strains. Some medically relevant species, such as A. calcoaceticus, A. lwoffii, A. nosocomialis, and A. pittii, have been found on vegetables, meat, dairy products, and human skin (16). Such strains have harbored extensive antibiotic resistance repertoires.…”