Acinetobacter pullorum sp. nov., Isolated from Chicken Meat

Abstract

The earliest account of Acinetobacter species dates back to 1911 when Beijerinck described an organism isolated from soil, originally named Micrococcus calcoaceticus [1]. The current genus designation was initially proposed by Brisou and Prévot in 1954, based on motility [2]. In 1968, a comprehensive survey completed by Baumann et al. provided sufficient data for a group species previously classified to at least 15 different genera and species and reclassified them to a single genus, for which the name Acinetobacter was proposed [2]. Currently, the genus Acinetobacter, which belongs to the class Gammaproteobacteria, is composed of 63 species with validly published names according to List of Prokaryotic names with Standing in Nomenclature, with Acinetobacter calcoaceticus as the type species (http://www.bacterio.net/acinetobacter.html; last accessed November 2019) and A. baumannii being the most clinically significant species, implicated in both nosocomial and community-derived infections [1]. This highly complex genus is widely distributed in soil, water, and animals, with members often associated with nosocomial infections-primarily aspiration pneumonia and catheter-associated bacteremia-as well as urinary tract infections [3]. The members are characteristically Gram-negative, oxidase-negative, strictly aerobic, and non-fermenting coccobacillus cells that occur in pairs under magnification [4] and exhibit twitching motility [5]. Typically, the DNA G+C content of Acinetobacter spp. is in the range of 34.9-47.0% [2, 6]. The major cellular fatty acids are typically C 18:1ω9c and C 16:0 [7], and the predominant polar lipid is phosphatidylethanolamine [8]. The major respiratory quinone is ubiquinone Q-9 [9]. In this study, we applied a polyphasic taxonomy approach to characterize and identify an isolate from raw chicken meat and proposed it as a novel species with the name Acinetobacter pullorum B301 T. Materials and Methods Bacterial Strains Strain B301 T was isolated from raw chicken meat obtained from a local market (Korea). Meat samples were homogenized in 225 ml of Dijkshoorn enrichment medium [10] in a stomacher for 2 min and incubated in a A bacterial strain, designated B301 T and isolated from raw chicken meat obtained from a local market in Korea, was characterized and identified using a polyphasic taxonomic approach. Cells were gram-negative, non-motile, obligate-aerobic coccobacilli that were catalase-positive and oxidase-negative. The optimum growth conditions were 30°C, pH 7.0, and 0% NaCl in tryptic soy broth. Colonies were round, convex, smooth, and cream-colored on tryptic soy agar. Strain B301 T has a genome size of 3,102,684 bp, with 2,840 protein-coding genes and 102 RNA genes. The 16S rRNA gene analysis revealed that strain B301 T belongs to the genus Acinetobacter and shares highest sequence similarity (97.12%) with A. celticus ANC 4603 T and A. sichuanensis WCHAc060041 T. The average nucleotide identity and digital DNA-DNA hybridization values for closely related species were below the cutoff va...

Precise Species Identification for Acinetobacter: a Genome-Based Study with Description of Two Novel Acinetobacter Species

“…A comparison of the physiological and biochemical features of the two type strains shows phenotype coherence, which is summarized in Table S2 in the supplemental material. According to previous reports ( 14 ), A. pullorum and A. portensis are different in the acidification of d -glucose and utilization of β-alanine and d -glucose, which is likely due to intraspecies variability or assay conditions. Based on principles by the International Code of Nomenclature of Bacteria ( 12 ), A. pullorum has the priority of species name over A. portensis .…”

“…During the process of studying WCHAc060012 T and WCHAc060115 T , we also found a pair of synonyms, namely, A. pullorum and A. portensis . A. pullorum B301 T was isolated from raw chicken meat at a local market in Korea ( 14 ). It has been shown that A. pullorum B301 T is closely related to Acinetobacter celticus ANC 4603 T ( 14 ).…”

“…A. pullorum B301 T was isolated from raw chicken meat at a local market in Korea ( 14 ). It has been shown that A. pullorum B301 T is closely related to Acinetobacter celticus ANC 4603 T ( 14 ). Four A. portensis strains were isolated from raw meat samples in supermarkets in Porto, Portugal.…”

“…Validly published names refer to those published in the International Journal of Systematic and Evolutionary Microbiology, the official journal of the International Committee on Systematics of Prokaryotes, including its validation lists ( 12 ). New Acinetobacter species are continuingly being reported, and the number of Acinetobacter species increases every year, with 6 novel species in 2017, 3 in 2018, 4 in 2019. and 9 in 2020 ( 11 , 13 – 18 ). However, the taxonomy of Acinetobacter is complicated by the presence of synonyms ( 19 – 22 ).…”

Chryseobacterium vaccae sp. nov., isolated from raw cow's milk

“…In addition, a phylogenetic tree was reconstructed using 361 core genes present in all of the reference genomes used in this study (Table S1) according to the methods described previously [34]. Briefly, protein-coding genes present in the genomes were identified using Prodigal software [35] and protein sequences in all genomes were clustered with 50 % sequence identity and 80 % alignment cutoffs using Linclust software [36].…”