Acinetobacter soli sp. nov., isolated from forest soil

Acinetobacter corruptisaponis sp. nov., Isolated from a Spoiled Bath Lotion

Strain DM2021935T representing a novel Acinetobacter species was isolated from a spoiled bath lotion in Guangdong, China. Based on 16S rRNA gene phylogenetic analysis, strain DM2021935T was closely related to 'Acinetobacter thutiue' VNH17T, Acinetobacter junii CIP 64.5 T, and Acinetobacter tibetensis Y-23 T. Cells of strain DM2021935T were Gram-stain-negative, non-spore-forming, strictly aerobic, catalase-positive, oxidase-negative, α-hemolytic, and non-motile. Strain DM2021935T exhibited growth in 1-3% (w/v) NaCl at temperatures ranging from 4 to 37 °C and tolerated pH levels from 6.0 to 8.0. The predominant fatty acids in strain DM2021935T are C12:0, C16:0, C18:1 ω9c, and summed feature 3. Polar lipid profiles included glycolipids, phospholipids, phosphatidylethanolamine, and phosphatidyl-N-methylethanolamine. The identified respiratory quinones were ubiquinone Q-8 and Q-9. The genomic size of DM2021935T comprised 4.15 Mb, consisting of one chromosome (3,827,633 bp) and two plasmids (241,357 and 83,010 bp). The G + C content was 41.8%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between strain DM2021935T and phylogenetically related type strains were below the species delineation thresholds (72.2-95.4, 53.1-87.0, and 20.4-66.4%, respectively). AntiSMASH analysis identified four gene clusters: non-ribosomal peptide synthetase, non-alpha poly-amino group acids, YcaO cyclodehydratase, and aryl polyene biosynthesis. Based on genotypic data, strain DM2021935T represents a novel species within the genus Acinetobacter. The proposed name for the novel species is Acinetobacter corruptisaponis sp. nov. (type strain DM2021935T = KCTC 92772 T = GDMCC 1.3703 T).

Exploring the biotechnological potential of Acinetobacter soli ANG344B: A novel bacterium for 2-phenylethanol production

A bacterium, Acinetobacter soli ANG344B, isolated from river water, exhibited an exceptional capacity to produce 2-phenylethanol (2-PE) using L-phenylalanine (L-Phe) as a precursor-a capability typically observed in yeasts rather than bacteria. Bioreactor experiments were conducted to evaluate the production performance, using glucose as the carbon source for cellular growth and L-Phe as the precursor for 2-PE production. Remarkably, A. soli ANG344B achieved a 2-PE concentration of 2.35 ± 0.26 g/L in just 24.5 h of cultivation, exhibiting a global volumetric productivity of 0.10 ± 0.01 g/L.h and a production yield of 0.51 ± 0.01 g2-PE/gL-Phe, a result hitherto reported only for yeasts. These findings position A. soli ANG344B as a highly promising microorganism for 2-PE production. Whole-genome sequencing of A. soli strain ANG344 revealed a genome size of 3.52 Mb with a GC content of 42.7 %. Utilizing the Rapid Annotation using Subsystem Technology (RAST) server, 3418 coding genes were predicted, including genes coding for enzymes previously associated with the metabolic pathway of 2-PE production in other microorganisms, yet unreported in Acinetobacter species. Through gene mapping, 299 subsystems were identified, exhibiting 30 % subsystem coverage. The whole genome sequence data was submitted to NCBI GeneBank with the BioProject ID PRJNA982713. These draft genome data offer significant potential for exploiting the biotechnological capabilities of A. soli strain ANG344 and for conducting further comparative genomic studies.

First report of New Delhi metallo-β-lactamase-1-producing Acinetobacter soli in Japan

New Delhi metallo-β-lactamase (NDM)-producing gram-negative rods, including Acinetobacter species, are a global problem but have rarely been isolated in Japan. To our knowledge, this is the first study to isolate an NDM-1-producing Acinetobacter soli strain, KUH106, in Japan. We analyzed this strain using next-generation sequencing to examine the plasmid carrying NDM-1. This plasmid, named pKUH106_NDM1, is 41,135 bp in length and contains genetic contexts with the structure ISAba14-aph(3')-VI-ISAba125-blaNDM-1ble-MBL. Comparative analysis of the plasmid revealed that it resembled the plasmids of Acinetobacter detected in various countries, such as the A. soli isolate from Taiwan and the Acinetobacter baumannii isolate from a healthcare facility in Osaka Prefecture, Japan. These results suggest that blaNDM-1 may spread via this plasmid in Acinetobacter species. This phenomenon needs to be confirmed through the genetic analysis of A. baumannii and other carbapenem-resistant Acinetobacter species. In particular, blaNDM-1 and other resistance genes must be investigated, and the spread of these genes in the community must be cautioned.

Acinetobacter entericus sp. nov., isolated from the gut of plastic-eating insect larvae Zophobas atratus

A Gram-negative, non-motile and rod-shaped strain, BIT-DXN8T, was isolated from the gut of plastic-eating insect larvae Zophobas atratus. The taxonomic position of this new isolate was examined by using a polyphasic approach. A preliminary analysis based on the 16S rRNA gene sequence (1411 bp) indicated that the most similar strain to BIT-DXN8T was Acinetobacter bouvetii DSM 14964T (98.5%), followed by Acinetobacter haemolyticus CIP 64.3T (98.2%) and Acinetobacter pullicarnis S23T (98.2%). The results of phylogenetic analyses, based on the 16S rRNA gene, concatenated sequences of five housekeeping genes (fusA, gyrB, recA, rplB and rpoB) and genome sequences, placed strain BIT-DXN8T in a separate lineage among the genus Acinetobacter of the family Moraxellaceae. The average nucleotide identity and digital DNA-DNA hybridization values of the strain when compared to all other species within the genus Acinetobacter were below 96 and 70 %, respectively. The physiological and biochemical tests confirm the affiliation of strain BIT-DXN8T to the present species within the genus Acinetobacter, but with some specific phenotypic differences. Therefore, strain BIT-DXN8T is considered to represent a novel species, for which the name Acinetobacter entericus sp. nov. is proposed. The type strain is BIT-DXN8T (=CCTCC AB 2022117T=KCTC 92696T).

Microbial Characterization of Arctic Glacial Ice Cores with a Semiautomated Life Detection System

The search for extant microbial life will be a major focus of future astrobiology missions; however, no direct extant life detection instrumentation is included in current missions to Mars. In this study, we developed the semiautomated MicroLife detection platform that collects and processes environmental samples, detects biosignatures, and characterizes microbial activity. This platform is composed of a drill for sample collection, a redox dye colorimetric system for microbial metabolic activity detection and assessment (μMAMA [microfluidics Microbial Activity MicroAssay]), and a MinION sequencer for biosignature detection and characterization of microbial communities. The MicroLife platform was field-tested on White Glacier on Axel Heiberg Island in the Canadian high Arctic, with two extracted ice cores. The μMAMA successfully detected microbial metabolism from the ice cores within 1 day of incubation. The MinION sequencing of the ice cores and the positive μMAMA card identified a microbial community consistent with cold and oligotrophic environments. Furthermore, isolation and identification of microbial isolates from the μMAMA card corroborated the MinION sequencing. Together, these analyses support the MicroLife platform's efficacy in identifying microbes natively present in cryoenvironments and detecting their metabolic activity. Given our MicroLife platform's size and low energy requirements, it could be incorporated into a future landed platform or rovers for life detection.

Phylogenetic Tree 16S rRNA Gene of Acinetobacter soli Isolated from the Prepuce of Aceh Cattle

BACKGROUND: In the pre-seed area of healthy Aceh cattle, it is possible to be contaminated with pathogenic bacteria that can interfere with the reproductive system. This study is needed to identify these pathogenic bacteria using a molecular approach, in an effort to prevent infection. AIM: The aim of the present study was to construct phylogenetic tree relationships of Acinetobacter soli identified in the preputial area of Aceh cattle by molecular analysis using 16S rRNA gene sequencing. MATERIALS AND METHODS: A total of 75 preputial specimens were obtained from Indrapuri’s Breeding and Forages Center of Aceh Cattles, Indrapuri district, Banda Aceh, Indonesia. The samples were processed for culture using standard conventional methods. The extraction of genomic DNA and the amplification of the 16S rRNA gene were assayed using polymerase chain reaction. A phylogenetic tree was constructed using distance matrices using the neighbor-joining model of the molecular evolutionary genetic analysis software 6.1 software. RESULTS: The results showed that of 75 preputial swab samples, 18 (24%) were positive for A. soli isolates. There was a 100% sequence similarity to A. soli prototype strain B1 and a 99% similarity to Acinetobacter parvus prototype strain LUH4616, Acinetobacter baylyi strain B2, A. venetianus strain ATCC 31012, as well as a 99% similarity to Acinetobacter baumannii strain DSM 30007, the strain ATCC 19606, and the strain JCM 6841, respectively. We concluded that A. soli-positive presentation in the preparation of Aceh cattle has 100% sequence similarity of 16S rRNA with A. soli strain B1. CONCLUSIONS: The conclusion of this study is that, based on the construction of a phylogenetic tree, it shows that 24% of the bacterial isolate is related to A. soli. It is essential to conduct a regular survey for bacterial contamination and to increase worker awareness and education about hygiene standards.

The microbial RNA metagenome of Aedes albopictus (Diptera: Culicidae) from Germany

Aedes albopictus is a highly invasive mosquito species that has become widespread across the globe. In addition, it is an efficient vector of numerous pathogens of medical and veterinary importance, including dengue, chikungunya and Zika viruses. Among others, the vector potential of mosquitoes is influenced by their microbiome. However, this influence is very dynamic and can vary between individuals and life stages. To obtain a rough overview on the microbiome of Ae. albopictus populations in Germany, pooled female and pooled male individuals from seven German locations were investigated by total RNA sequencing. The mosquito specimens had been collected as larvae in the field and processed immediately after adult emergence, i.e. without females having fed on blood. RNA fragments with high degrees of identity to a large number of viruses and microorganisms were identified, including, for example, Wolbachia pipientis and Acinetobacter baumannii, with differences between male and female mosquitoes. Knowledge about the natural occurrence of microorganisms in mosquitoes may be translated into new approaches to vector control, for example W. pipientis can be exploited to manipulate mosquito reproduction and vector competence. The study results show how diverse the microbiome of Ae. albopictus can be, and the more so needs to be adequately analysed and interpreted.

Microbial community origin and fate through a rural wastewater treatment plant

Conventional wastewater treatment relies on a complex microbiota; however, much of this community is still to be characterised. To better understand the origin, dynamics and fate of bacteria within a wastewater treatment plant: untreated primary wastewater, activated sludge, and post-treatment effluent were characterised. From 3,163 Exact Sequence Variants (ESVs), 860 were annotated to species-level. In primary wastewater, 28% of ESVs were putative bacterial species previously associated with humans, 14% with animals and 5% as common to the environment. Differential abundance analysis revealed significant relative reductions in ESVs from potentially humans-associated species from primary wastewater to activated sludge, and significant increases in ESVs from species associated with nutrient cycling. Between primary wastewater and effluent, 51% of ESVs from human-associated species did not significantly differ, and species such as Bacteroides massiliensis and Bacteroides dorei increased. These findings illustrate that activated sludge increased extracellular protease and urease-producing species, ammonia and nitrite oxidizers, denitrifiers and specific phosphorus accumulators. Although many human-associated species declined, some persisted in effluent, including strains of potential health or environmental concern. Species-level microbial assessment may be useful for understanding variation in wastewater treatment efficiency as well as for monitoring the release of microbes into surface water and the wider ecosystem. This article is protected by copyright. All rights reserved.

Imported Pet Reptiles and Their “Blind Passengers”—In-Depth Characterization of 80 Acinetobacter Species Isolates

Reptiles are popular pet animals and important food sources, but the trade of this vertebrate class is—besides welfare and conservation—under debate due to zoonotic microbiota. Ninety-two shipments of live reptiles were sampled during border inspections at Europe’s most relevant transshipment point for the live animal trade. Acinetobacter spp. represented one significant fraction of potentially MDR bacteria that were further analyzed following non-selective isolation or selective enrichment from feces, urinate, or skin samples. Taxonomic positions of respective isolates were confirmed by MALDI-TOF MS and whole-genome sequencing analysis (GBDP, dDDH, ANIb, and rMLST). The majority of the 80 isolates represented established species; however, a proportion of potentially novel taxa was found. Antimicrobial properties and genome-resistance gene screening revealed novel and existing resistance mechanisms. Acinetobacter spp. strains were most often resistant to 6–10 substance groups (n = 63) in vitro. Resistance to fluorchinolones (n = 4) and colistin (n = 7), but not to carbapenems, was noted, and novel oxacillinase variants (n = 39) were detected among other genes. Phylogenetic analysis (MLST) assigned few isolates to the known STs (25, 46, 49, 220, and 249) and to a number of novel STs. No correlation was found to indicate that MDR Acinetobacter spp. in reptiles were associated with harvesting mode, e.g., captive-bred, wild-caught, or farmed in natural ecosystems. The community of Acinetobacter spp. in healthy reptiles turned out to be highly variable, with many isolates displaying a MDR phenotype or genotype.

Seasonal Dynamics of Bacterial Community Structure in Diesel Oil-Contaminated Soil Cultivated with Tall Fescue (Festuca arundinacea)

The objective of this study was to explore the seasonal characteristics of rhizoremediation and the bacterial community structure over the course of a year in soil contaminated with diesel oil. The soil was contaminated with diesel oil at a total petroleum hydrocarbon (TPH) concentration of 30,000 mg-TPH·kg-soil⁻¹. Tall fescue seedlings were planted in the contaminated soil and rhizoremediation performance was monitored for 317 days. The TPH concentration gradually declined, reaching 75.6% after day 61. However, the TPH removability decreased by up to 30% after re-contamination in the fall and winter. The bacterial community structure exhibited distinct seasonal dynamics. Genus Pseudomonas significantly increased up to 55.7% in the winter, while the genera Immundisolibacter and Lysobacter, well-known petroleum hydrocarbon (PH)-degrading bacteria, were found to be positively linked to the TPH removal rate. Consequently, knowledge of this seasonal variation in rhizoremediation performance and the bacterial community structure is useful for the improvement of rhizoremediation in PH-contaminated environments.

Draft Genome Sequence and Annotation of Acinetobacter soli AS15, Isolated from an Irish Hospital

We report the draft genome sequence of Acinetobacter soli AS15, which was isolated in 2018 from a rectal screen of a patient at St. Vincent’s University Hospital (Dublin, Ireland). The draft genome sequence is 3,589,002 bp and was assembled into 82 contigs.

Coming from the Wild: Multidrug Resistant Opportunistic Pathogens Presenting a Primary, Not Human-Linked, Environmental Habitat

The use and misuse of antibiotics have made antibiotic-resistant bacteria widespread nowadays, constituting one of the most relevant challenges for human health at present. Among these bacteria, opportunistic pathogens with an environmental, non-clinical, primary habitat stand as an increasing matter of concern at hospitals. These organisms usually present low susceptibility to antibiotics currently used for therapy. They are also proficient in acquiring increased resistance levels, a situation that limits the therapeutic options for treating the infections they cause. In this article, we analyse the most predominant opportunistic pathogens with an environmental origin, focusing on the mechanisms of antibiotic resistance they present. Further, we discuss the functions, beyond antibiotic resistance, that these determinants may have in the natural ecosystems that these bacteria usually colonize. Given the capacity of these organisms for colonizing different habitats, from clinical settings to natural environments, and for infecting different hosts, from plants to humans, deciphering their population structure, their mechanisms of resistance and the role that these mechanisms may play in natural ecosystems is of relevance for understanding the dissemination of antibiotic resistance under a One-Health point of view.

Comparative phylo-pangenomics reveals generalist lifestyles in representative Acinetobacter species and proposes candidate gene markers for species identification

Acinetobacter species have the potential to invade and colonize immunocompromised patients, therefore being well-known as opportunistic pathogens. Among these bacteria, the species of the Acinetobacter calcoaceticus-Acinetobacter baumannii "complex" (Acb members) emerge as the main often isolated bacteria in clinical specimens. The unequivocal taxonomy is crucial to correctly identify these species and associated with comparative genomic analyses aids to understand their life-styles as well. In this study, all publicly available Acinetobacter species at the date of this study preparation were analyzed. The results revealed that the Acb members are in fact a complex when phenotypic methods are confronted, while for comparative and phylogenomics analyses this term is misleading, since they composed a monophyletic group instead. Nine best gene markers (response regulator, recJ, recG, phosphomannomutase, pepSY, monovalent cation/H + antiporter subunit D, mnmE, glnE, and bamA) were selected for identification of Acinetobacter species. Moreover, representative strains of each species were split according their isolation sources in the categories: environmental, human, insect and non-human vertebrate. Neither niche-specific genome signature nor niche-associated functional and pathogenic potential were associated with their isolation source, meaning it is not the main force acting on Acinetobacter adaptation in a given niche and corroborating that their ubiquitous distribution is a reflex of their generalist life-styles.

Acinetobacter stercoris sp. nov. isolated from output source of a mesophilic german biogas plant with anaerobic operating conditions

The Gram-stain-negative, oxidase negative, catalase positive strain KPC-SM-21^T, isolated from a digestate of a storage tank of a mesophilic German biogas plant, was investigated by a polyphasic taxonomic approach. Phylogenetic identification based on the nearly full-length 16S rRNA gene revealed highest gene sequence similarity to Acinetobacter baumannii ATCC 19606^T (97.0%). Phylogenetic trees calculated based on partial rpoB and gyrB gene sequences showed a distinct clustering of strain KPC-SM-21^T with Acinetobacter gerneri DSM 14967^T = CIP 107464^T and not with A. baumannii, which was also supported in the five housekeeping genes multilocus sequence analysis based phylogeny. Average nucleotide identity values between whole genome sequences of strain KPC-SM-21^T and next related type strains supported the novel species status. The DNA G + C content of strain KPC-SM-21^T was 37.7 mol%. Whole-cell MALDI-TOF MS analysis supported the distinctness of the strain to type strains of next related Acinetobacter species. Predominant fatty acids were C_18:1 ω9c (44.2%), C_16:0 (21.7%) and a summed feature comprising C_16:1 ω7c and/or iso-C_15:0 2-OH (15.3%). Based on the obtained genotypic, phenotypic and chemotaxonomic data we concluded that strain KPC-SM-21^T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter stercoris sp. nov. is proposed. The type strain is KPC-SM-21^T (= DSM 102168^T = LMG 29413^T).

Acinetobacter lanii sp. nov., Acinetobacter shaoyimingii sp. nov. and Acinetobacter wanghuae sp. nov., isolated from faeces of Equus kiang

Six aerobic, non-motile, non-haemolytic, Gram-stain-negative, oxidase-negative strains (185^T, 187, 323-1^T, 194, dk386^T and dk771) were recovered from different faecal samples of Equus kiang on the Qinghai-Tibet Plateau. In the 16S rRNA gene sequences, one strain pair, 185^T/187, shared highest similarity to Acinetobacter equi 114^T (97.9 %), and the other two (323-1^T/194 and dk771^T/dk386) to Acinetobacter harbinensis CGMCC 1.12528^T (98.6 and 97.0 %, respectively). Phylogenomic tree analysis showed that these six strains formed three separate clades in the genus Acinetobacter. Digital DNA-DNA hybridization values of each pair of the isolates with all members of the genus Acinetobacter were far below 70 %. The main cellular fatty acids of all six strains were C_18 : 1  ω9c, C_16 : 0 and summed feature 3 (C_16 : 1  ω7c/C_16 : 1  ω6c). Q-9 was the predominant respiratory quinone for strains 185^T, 323-1^T and dk386^T. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on the genotypic, phenotypic and biochemical analyses, these six strains represent three novel species of the genus Acinetobacter, for which the names Acinetobacter lanii sp. nov., Acinetobacter shaoyimingii sp. nov. and Acinetobacter wanghuae sp. nov. are proposed. The type strains are 185^T (=CGMCC 1.13636^T=JCM 33607^T), 323-1^T (=CGMCC 1.13940^T=JCM 33608^T) and dk386^T (=CGMCC 1.16589^T=JCM 33592^T), respectively.

Acinetobacter pullicarnis sp. nov. isolated from chicken meat

A novel bacterial strain, named S23^T, was isolated from chicken meat of local market in Korea. Cells were Gram-negative, milky-yellow colored, non-motile and coccobacillus. The strain was obligate aerobic and catalase-positive, oxidase-negative, optimum growth temperature and pH were 25 °C and pH 7.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain S23^T belongs to the genus Acinetobacter and is most closely related to Acinetobacter defluvii KCTC 52503 ^T (97.40%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) value between strain S23^T and its closet phylogenetic neighbors was below 76% and 17%, respectively. The G + C content of genomic DNA of strain S23^T was 41.53 mol%. The major respiratory quinone was Q-9. The major cellular fatty acids were summed feature 3 (comprising C_16:1ω7c and/or C_16:1ω6c), C_18:1ω9c, and C_16:0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanol-amine, and phosphatidylserine. The ANI and dDDH results and results of the genotypic analysis in combination with chemotaxonomic and physiological data demonstrated that strain S23^T represented a novel species within the genus Acinetobacter, for which the name Acinetobacter pullicarnis sp. nov. is proposed. The strain type is S23^T (= KACC 19921 ^T = JCM 33150 ^T).

Honeydew-associated microbes elicit defense responses against brown planthopper in rice

Feeding of sucking insects, such as the rice brown planthopper (Nilaparvata lugens; BPH), causes only limited mechanical damage on plants that is otherwise essential for injury-triggered defense responses against herbivores. In pursuit of complementary BPH elicitors perceived by plants, we examined the potential effects of BPH honeydew secretions on the BPH monocot host, rice (Oryza sativa). We found that BPH honeydew strongly elicits direct and putative indirect defenses in rice, namely accumulation of phytoalexins in the leaves, and release of volatile organic compounds from the leaves that serve to attract natural enemies of herbivores, respectively. We then examined the elicitor active components in the honeydew and found that bacteria in the secretions are responsible for the activation of plant defense. Corroborating the importance of honeydew-associated microbiota for induced plant resistance, BPHs partially devoid of their microbiota via prolonged antibiotics ingestion induced significantly less defense in rice relative to antibiotic-free insects applied to similar groups of plants. Our data suggest that rice plants may additionally perceive herbivores via their honeydew-associated microbes, allowing them to discriminate between incompatible herbivores-that do not produce honeydew-and those that are compatible and therefore dangerous.

The natural environment as a reservoir of pathogenic and non-pathogenic Acinetobacter species

Acinetobacter is a genus of Gram-negative bacteria, which are oxidase-negative, exhibiting a twitching motility under a magnifying lens. Besides being important soil microorganisms, due to their contribution to the soil fertility, Acinetobacter species, particularly A. baumannii, hold a prominent place within the genus because, it is the most virulent among the other species, causing varying degrees of human infections in clinical environments. However, results of different research have shown that Acinetobacter species can be isolated from such natural environments as surface water, wastewater and sewage, healthy human skin, plant, animal and food material as well as domestic appliances. The presence of some other Acinetobacter species in the natural environment has been associated with beneficial roles including soil improvement, detoxification of oil spillages and as microflora in human and plant bodies. In this paper, we carried out an overview of various natural ecological niches as reservoirs of pathogenic and non-pathogenic Acinetobacter species.

Acinetobacter calcoaceticus CSY-P13 Mitigates Stress of Ferulic and p-Hydroxybenzoic Acids in Cucumber by Affecting Antioxidant Enzyme Activity and Soil Bacterial Community

Ferulic acid (FA) and p-hydroxybenzoic acid (PHBA) are main phenolic compounds accumulated in rhizosphere of continuously cropped cucumber, causing stress in plants. Microbial degradation of a mixture of FA and PHBA is not well understood in soil. We isolated a strain CSY-P13 of Acinetobacter calcoaceticus, inoculated it into soil to protect cucumber from FA and PHBA stress, and explored a mechanism underlying the protection. CSY-P13 effectively degraded a mixture of FA and PHBA in culture solution under conditions of 39.37°C, pH 6.97, and 21.59 g L-1 potassium dihydrogen phosphate, giving rise to 4-vinyl guaiacol, vanillin, vanillic acid, and protocatechuic acid. During FA and PHBA degradation, activities of superoxide dismutase (SOD), catalase, ascorbate peroxidase, and dehydroascorbate reductase in CSY-P13 were induced. Inoculated into cucumber-planted soil containing 220 μg g-1 mixture of FA and PHBA, CSY-P13 degraded FA and PHBA in soil, increased plant height, and decreased malonaldehyde, superoxide radical, and hydrogen peroxide levels in leaves. CSY-P13 also enhanced SOD, guaiacol peroxidase, catalase, glutathione peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activities; increased ascorbate and glutathione contents; and elevated transcript levels of copper/zinc SOD, manganese SOD, and catalase in leaves under FA and PHBA. Moreover, CSY-P13 increased phosphatase, catalase, urease, and sucrase activities and changed bacterial richness, diversity, and community composition by high throughput sequencing in cucumber-planted soil supplemented with the mixture of FA and PHBA. So CSY-P13 degrades the mixture of FA and PHBA in soil and mitigates stress from the two phenolic compounds in cucumber by activating antioxidant enzymes, changing soil bacterial community, and inducing soil enzymes.

Acinetobacter larvae sp. nov., isolated from the larval gut of Omphisa fuscidentalis

A Gram-stain-negative, non-spore-forming, non-motile and aerobic coccobacilli-shaped strain, designated BRTC-1T, was isolated from the gut of Omphisa fuscidentalis Hampson, which is a larva of a moth and was collected from Xishuangbanna Dai Autonomous Prefecture in China. The isolate was found to grow at NaCl concentrations of 0-5 % (w/v) (optimum: 0 %), 10-45 °C (optimum: 30-35 °C) and pH 5.0-9.0 (optimum: pH 6.0) on tryptic soy agar. Analysis of the 16S rRNA gene sequence indicated that the isolate belonged to the genus Acinetobacter and was most closely related to Acinetobacter rudis LMG 26107T, Acinetobacter guillouiae LMG 988T and Acinetobacter bereziniae LMG 1003T with 96.4, 96.3 and 96.3 % sequence similarity, respectively. The comparative sequence analyses of the rpoB and gyrB genes showed that BRTC-1T is distant from the species of the genus Acinetobacter with validly published names (≤84.0 and ≤82.0 % similarity, respectively). The average nucleotide identity and digital DNA-DNA hybridization values (≤77.0 and ≤22.8 %, respectively) between the whole-genome sequence of BRTC-1T and those of the known taxa were far below the thresholds used to discriminate bacterial species. The major fatty acids were determined to be C16 : 0, C18 : 1ω9c and C16 : 1ω7c/iso-C15 : 0 2-OH. The respiratory quinone was Q-9. The polar lipids were found to be diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, five phospholipids and one phosphatidylcholine. Based on its phenotypic and chemotaxonomic characteristics from this study, the isolate is concluded to represent a novel species of the genus Acinetobacter, for which the name Acinetobacter larvae sp. nov. is proposed. The type strain is BRTC-1T (=ACCC 19936T=JCM 31367T).

Acinetobacter halotolerans sp. nov., a novel halotolerant, alkalitolerant, and hydrocarbon degrading bacterium, isolated from soil

A novel aerobic, non-motile, halotolerant, alkalitolerant, hydrocarbon degrading, and rod shaped bacterium, designated strain R160^T, was isolated from soil in South Korea. Cells were Gram-staining-negative, catalase-positive, and oxidase-negative. This strain grew up to 7% of NaCl and in the pH range of 6-11 (optimum 7.0-10.0). The isolate degraded 51.7 ± 1.3% of hydrocarbon components (C-18, C-20, and C-22) and 45.8 ± 1.4% oil components (kerosene, diesel, and gasoline). Phylogenetic analysis based on 16 S rRNA gene sequences revealed that strain R160^T formed a lineage within the genus Acinetobacter, and was closely related to 'Acinetobacter oleivorans' DR1^T (97.47%, sequence similarity). Other closely related members have sequence similarity between 97.47 to 96.52%. The predominant respiratory lipoquinones of strain R160^T were ubiquinone 9 (Q-9) and ubiquinone 8 (Q-8). The major polar lipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and phosphatidylcholine (PC). The major cellular fatty acids were 9-octadecenoic acid (C_18:1 ω9c), hexadecanoic acid (C_16:0), and summed feature (comprising C_16:1 ω7c and/or C_16:1 ω6c). The DNA G + C content of strain R160^T was 44.9 mol%. On the basis of phenotypic, genotypic, chemotaxonomic, and phylogenetic characteristics, strain R160^T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter halotolerans sp. nov. is proposed. The type strain is R160^T (= KEMB 9005-333^T = KACC 18453^T = JCM 31009^T).

Exploring the Impacts of Postharvest Processing on the Microbiota and Metabolite Profiles during Green Coffee Bean Production

The postharvest treatment and processing of fresh coffee cherries can impact the quality of the unroasted green coffee beans. In the present case study, freshly harvested Arabica coffee cherries were processed through two different wet and dry methods to monitor differences in the microbial community structure and in substrate and metabolite profiles. The changes were followed throughout the postharvest processing chain, from harvest to drying, by implementing up-to-date techniques, encompassing multiple-step metagenomic DNA extraction, high-throughput sequencing, and multiphasic metabolite target analysis. During wet processing, a cohort of lactic acid bacteria (i.e., Leuconostoc, Lactococcus, and Lactobacillus) was the most commonly identified microbial group, along with enterobacteria and yeasts (Pichia and Starmerella). Several of the metabolites associated with lactic acid bacterial metabolism (e.g., lactic acid, acetic acid, and mannitol) produced in the mucilage were also found in the endosperm. During dry processing, acetic acid bacteria (i.e., Acetobacter and Gluconobacter) were most abundant, along with Pichia and non-Pichia (Candida, Starmerella, and Saccharomycopsis) yeasts. Accumulation of associated metabolites (e.g., gluconic acid and sugar alcohols) took place in the drying outer layers of the coffee cherries. Consequently, both wet and dry processing methods significantly influenced the microbial community structures and hence the composition of the final green coffee beans. This systematic approach to dissecting the coffee ecosystem contributes to a deeper understanding of coffee processing and might constitute a state-of-the-art framework for the further analysis and subsequent control of this complex biotechnological process.

IMPORTANCE

Coffee production is a long process, starting with the harvest of coffee cherries and the on-farm drying of their beans. In a later stage, the dried green coffee beans are roasted and ground in order to brew a cup of coffee. The on-farm, postharvest processing method applied can impact the quality of the green coffee beans. In the present case study, freshly harvested Arabica coffee cherries were processed through wet and dry processing in four distinct variations. The microorganisms present and the chemical profiles of the coffee beans were analyzed throughout the postharvest processing chain. The up-to-date techniques implemented facilitated the investigation of differences related to the method applied. For instance, different microbial groups were associated with wet and dry processing methods. Additionally, metabolites associated with the respective microorganisms accumulated on the final green coffee beans.

Degradation of cis- and trans-(4-methylcyclohexyl) methanol in activated sludge

Crude (4-methylcyclohexyl)methanol (MCHM) caused extensive contamination of drinking water, wastewater, and the environment during the 2014 West Virginia Chemical Spill. However, information related to the environmental degradation of cis- and trans-4-MCHM, the main components of the crude 4-MCHM mixture, remains largely unknown. This study is among the first to investigate the degradation kinetics and transformation of 4-MCHM isomers in activated sludge. The 4-MCHM loss was mainly due to biodegradation to form carbon dioxide (CO2), plus acetic, propionic, isobutyric, and isovaleric acids with little contribution from adsorption. The biodegradation of 4-MCHM isomers followed the first-order kinetic model with half-lives higher than 0.50 days. Nitrate augmented the degradation of 4-MCHM isomers, while glucose and acetate decreased their degradation. One 4-MCHM-degrading bacterium isolated from activated sludge was identified as Acinetobacter bouvetii strain EU40 based on 16S rRNA gene sequences. This study will enhance the prediction of the environmental fate of 4-MCHM in water treatment systems.

Utility of Whole-Genome Sequencing in Characterizing Acinetobacter Epidemiology and Analyzing Hospital Outbreaks

Acinetobacter baumannii frequently causes nosocomial infections and outbreaks. Whole-genome sequencing (WGS) is a promising technique for strain typing and outbreak investigations. We compared the performance of conventional methods with WGS for strain typing clinical Acinetobacter isolates and analyzing a carbapenem-resistant A. baumannii (CRAB) outbreak. We performed two band-based typing techniques (pulsed-field gel electrophoresis and repetitive extragenic palindromic-PCR), multilocus sequence type (MLST) analysis, and WGS on 148 Acinetobacter calcoaceticus-A. baumannii complex bloodstream isolates collected from a single hospital from 2005 to 2012. Phylogenetic trees inferred from core-genome single nucleotide polymorphisms (SNPs) confirmed three Acinetobacter species within this collection. Four major A. baumannii clonal lineages (as defined by MLST) circulated during the study, three of which are globally distributed and one of which is novel. WGS indicated that a threshold of 2,500 core SNPs accurately distinguished A. baumannii isolates from different clonal lineages. The band-based techniques performed poorly in assigning isolates to clonal lineages and exhibited little agreement with sequence-based techniques. After applying WGS to a CRAB outbreak that occurred during the study, we identified a threshold of 2.5 core SNPs that distinguished nonoutbreak from outbreak strains. WGS was more discriminatory than the band-based techniques and was used to construct a more accurate transmission map that resolved many of the plausible transmission routes suggested by epidemiologic links. Our study demonstrates that WGS is superior to conventional techniques for A. baumannii strain typing and outbreak analysis. These findings support the incorporation of WGS into health care infection prevention efforts.

Reservoirs of Non-baumannii Acinetobacter Species

Acinetobacter spp. are ubiquitous gram negative and non-fermenting coccobacilli that have the ability to occupy several ecological niches including environment, animals and human. Among the different species, Acinetobacter baumannii has evolved as global pathogen causing wide range of infection. Since the implementation of molecular techniques, the habitat and the role of non-baumannii Acinetobacter in human infection have been elucidated. In addition, several new species have been described. In the present review, we summarize the recent data about the natural reservoir of non-baumannii Acinetobacter including the novel species that have been described for the first time from environmental sources and reported during the last years.

High prevalence of bla OXA-23 in Acinetobacter spp. and detection of bla NDM-1 in A. soli in Cuba: report from National Surveillance Program (2010-2012)

As a first national surveillance of Acinetobacter in Cuba, a total of 500 Acinetobacter spp. isolates recovered from 30 hospitals between 2010 and 2012 were studied. Acinetobacter baumannii–calcoaceticus complex accounted for 96.4% of all the Acinetobacter isolates, while other species were detected at low frequency (A. junii 1.6%, A. lwoffii 1%, A. haemolyticus 0.8%, A. soli 0.2%). Resistance rates of isolates were 34–61% to third-generation cephalosporins, 49–50% to β-lactams/inhibitor combinations, 42–47% to aminoglycosides, 42–44% to carbapenems and 55% to ciprofloxacin. However, resistance rates to colistin, doxycycline, tetracycline and rifampin were less than 5%. Among carbapenem-resistant isolates, 75% harboured different bla_OXA genes (OXA-23, 73%; OXA-24, 18%; OXA-58, 3%). The bla_NDM-1 gene was identified in an A. soli strain, of which the species was confirmed by sequence analysis of 16S rRNA gene, rpoB, rpoB–rpoC and rpoL–rpoB intergenic spacer regions and gyrB. The sequences of bla_NDM-1 and its surrounding genes were identical to those reported for plasmids of A. baumannii and A. lwoffi strains. This is the first report of bla_NDM-1 in A. soli, together with a high prevalence of OXA-23 carbapenemase for carbapenem resistance in Acinetobacter spp. in Cuba.

Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry-based VITEK MS system for the identification of Acinetobacter species from blood cultures: comparison with VITEK 2 and MicroScan systems

Background

Acinetobacter species are the leading cause of bloodstream infection (BSI), but their correct identification is challenging. We evaluated the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based VITEK MS (bioMérieux, France), and two automated systems, VITEK 2 (bioMérieux) and MicroScan (Siemens, USA) for identification of Acinetobacter BSI isolates.

Methods

A total of 187 BSI isolates recovered at a university hospital in Korea between 2010 and 2012 were analyzed. The identification results obtained using VITEK MS and two automated systems were compared with those of rpoB sequencing.

Results

Of 187 isolates analyzed, 176 were identified to the species level by rpoB sequencing: the Acinetobacter baumannii group (ABG; 101 A. baumannii, 43 A. nosocomialis, 10 A. pittii isolates) was most commonly identified (82.4%), followed by Acinetobacter genomic species 13BJ/14TU (5.3%), A. ursingii (2.1%), A. soli (2.1%), A. bereziniae (1.1%), and A. junii (1.1%). Correct identification rates to the species group (ABG) level or the species level was comparable among the three systems (VITEK MS, 90.3%; VITEK 2, 89.2%; MicroScan, 86.9%). However, VITEK MS generated fewer misidentifications (0.6%) than VITEK 2 (10.8%) and MicroScan (13.1%) (P<0.001). In addition, VITEK MS demonstrated higher specificity (100%) for discrimination between ABG and non-ABG isolates than the other systems (both, 31.8%) (P<0.001).

Conclusions

The VITEK MS system is superior to the VITEK 2 and MicroScan systems for identification of Acinetobacter BSI isolates, with fewer misidentifications and better discrimination between the ABG and non-ABG isolates.

Acinetobacter gandensis sp. nov. isolated from horse and cattle

We previously reported the presence of an OXA-23 carbapenemase in an undescribed species of the genus Acinetobacter isolated from horse dung at the Faculty of Veterinary Medicine, Ghent University, Belgium. Here we include six strains to corroborate the delineation of this taxon by phenotypic characterization, DNA-DNA hybridization, 16S rRNA gene and rpoB sequence analysis, % G+C determination, MALDI-TOF MS and fatty acid analysis. The nearly complete 16S rRNA gene sequence of strain UG 60467(T) showed the highest similarities with those of the type strains of Acinetobacter bouvetii (98.4 %), Acinetobacter haemolyticus (97.7 %), and Acinetobacter schindleri (97.2 %). The partial rpoB sequence of strain UG 60467(T) showed the highest similarities with 'Acinetobacter bohemicus' ANC 3994 (88.6 %), A. bouvetii NIPH 2281 (88.6 %) and A. schindleri CIP 107287T (87.3 %). Whole-cell MALDI-TOF MS analyses supported the distinctness of the group at the protein level. The predominant fatty acids of strain UG 60467(T) were C12 : 0 3-OH, C12 : 0, C16 : 0, C18 : 1ω9c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). Strains UG 60467(T) and UG 60716 showed a DNA-DNA relatedness of 84 % with each other and a DNA-DNA relatedness with A. schindleri LMG 19576(T) of 17 % and 20 %, respectively. The DNA G+C content of strain UG 60467(T) was 39.6 mol%. The name Acinetobacter gandensis sp. nov. is proposed for the novel taxon. The type strain is UG 60467(T) ( = ANC 4275(T) = LMG 27960(T) = DSM 28097(T)).

Acinetobacter apis sp. nov., isolated from the intestinal tract of a honey bee, Apis mellifera

A novel Gram-negative, obligate aerobic, non-motile, and both coccobacillus- and bacillus-shaped bacterium, designated strain HYN18(T), was isolated from the intestinal tract of a honey bee (Apis mellifera). The isolate was oxidase-negative and catalase-positive. Strain HYN18(T) showed optimum growth at 25°C, pH 6-7, and in the presence of 1% (w/v) NaCl in trypticase soy broth medium. The isolate was negative for hydrolyses of starch, casein, gelatin and urea, indole production from tryptone and hemolysis on sheep blood agar. A phylogenetic analysis based on the 16S rRNA gene and rpoB gene sequence showed that strain HYN18(T) was most closely related to Acinetobacter nectaris SAP 763.2(T) and A. boissieri SAP 284.1(T) with 98.3% and 98.1% similarity (16S rRNA gene), respectively, and 84.4% similarity with Acinetobacter nectaris SAP 763.2(T) (rpoB gene). The major cellular fatty acids were summed features 3 (comprising C16:1ω7c /C16:1ω6c ), C12:0 and C16:0. The main isoprenoid quinone was ubiquinone-9 (Q-9). The polar lipids of strain HYN18(T) were phosphatidylethanolamine, three unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The DNA G+C content was 40.6 mol%. DNA-DNA hybridization experiments indicated less than 33 ± 10% relatedness to the closest phylogenetic species, Acinetobacter nectaris SAP 763.2(T). Thus, the phenotypic, phylogenetic and genotypic analyses indicate that strain HYN18(T) is a novel species within the genus Acinetobacter, for which the name Acinetobacter apis is proposed. The type strain is HYN18(T) (=KACC 16906(T) =JCM 18575(T)).

Acinetobacter sp. isolates from emergency departments in two hospitals of South Korea

A total of 114 Acinetobacter sp. isolates were collected from patients in the emergency departments (EDs) of two Korean hospitals. Most isolates belonged to the Acinetobacter baumannii complex (105 isolates, 92.1 %). Imipenem resistance was found in 39 isolates (34.2 %) of the Acinetobacter sp. isolates, and 6 colistin-resistant isolates were also identified. Species distribution and antimicrobial-resistance rates were different between the two hospitals. In addition, two main clones were identified in the imipenem-resistant A. baumannii isolates from hospital B, but very diverse and novel genotypes were found in those from hospital A. Many Acinetobacter sp. isolates, including the imipenem-resistant A. baumannii, are considered to be associated with the community. The evidence of high antimicrobial resistance and different features in these Acinetobacter sp. isolates between the two EDs suggests the need for continuous testing to monitor changes in epidemiology.

Draft Genome Sequence of a Multidrug-Resistant bla NDM-1-Producing Acinetobacter soli Isolate in China

Acinetobacter spp. are one of the most prevalent opportunistic pathogens causing nosocomial infections and have become a major clinical and public health threat. In this study, we presented the first draft genome sequence of A. soli TCM341, a multidrug resistant isolate that carried the bla NDM-1 gene in China. Genome sequencing of A. soli TCM341 was carried out in Illumina Hiseq 2000 next-generation sequencer. The data obtained revealed 74 contigs with genome size of 3.49 Mb and G+C content of 41.37 %.

Acinetobacter harbinensis sp. nov., isolated from river water

A bacterial strain, HITLi 7T, with nitrifying ability was isolated from the surface water of the Songhua River in China. Cells were Gram-stain-negative, strictly aerobic, oxidase-negative, non-motile coccobacilli, capable of growth in mineral media with acetate as the sole carbon source and ammonia as the sole source of nitrogen. The cells did not grow at 37 °C, but did grow at 2 °C. The DNA G+C content was 45.5 mol%. Results of 16S rRNA gene sequence analysis indicated a close relationship between this isolate and Acinetobacter lwoffii (98.4 % similarity for strain DSM 2403T). rpoB and gyrB gene sequences did not show significant similarity with those from other species of the genus Acinetobacter . Predominant cellular fatty acids were 9-octadecenoic acid (C18 : 1ω9c) and summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). Acid was not produced from d-glucose, and gelatin was not hydrolysed by the isolate. Genotypic, phenotypic and chemotaxonomic data from this study indicate that the isolate should be classified as a representative of a novel species of the genus Acinetobacter . The name Acinetobacter harbinensis sp. nov. is proposed for the novel species, with HITLi 7T ( = CGMCC 1.12528T = KCTC 32411T) as the type strain.

High frequency of Acinetobacter soli among Acinetobacter isolates causing bacteremia at a tertiary hospital in Japan

Acinetobacter baumannii is generally the most frequently isolated Acinetobacter species. Sequence analysis techniques allow reliable identification of Acinetobacter isolates at the species level. Forty-eight clinical isolates of Acinetobacter spp. were obtained from blood cultures at Tohoku University Hospital. These isolates were identified at the species level by partial sequencing of the RNA polymerase β-subunit (rpoB), 16S rRNA, and gyrB genes. Then further characterization was done by using the PCR for detection of OXA-type β-lactamase gene clusters, metallo-β-lactamases, and carO genes. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing were also performed. The most frequent isolate was Acinetobacter soli (27.1%). Six of the 13 A. soli isolates were carbapenem nonsusceptible, and all of these isolates produced IMP-1. PFGE revealed that the 13 A. soli isolates were divided into 8 clusters. This study demonstrated that A. soli accounted for a high proportion of Acinetobacter isolates causing bacteremia at a Japanese tertiary hospital. Non-A. baumannii species were identified more frequently than A. baumannii and carbapenem-nonsusceptible isolates were found among the non-A. baumannii strains. These results emphasize the importance of performing epidemiological investigations of Acinetobacter species.

Identification of 50 class D β-lactamases and 65 Acinetobacter-derived cephalosporinases in Acinetobacter spp

Whole-genome sequencing of a collection of 103 Acinetobacter strains belonging to 22 validly named species and another 16 putative species allowed detection of genes for 50 new class D β-lactamases and 65 new Acinetobacter-derived cephalosporinases (ADC). All oxacillinases (OXA) contained the three typical motifs of class D β-lactamases, STFK, (F/Y)GN, and K(S/T)G. The phylogenetic tree drawn from the OXA sequences led to an increase in the number of OXA groups from 7 to 18. The topologies of the OXA and RpoB phylogenetic trees were similar, supporting the ancient acquisition of blaOXA genes by Acinetobacter species. The class D β-lactamase genes appeared to be intrinsic to several species, such as Acinetobacter baumannii, Acinetobacter pittii, Acinetobacter calcoaceticus, and Acinetobacter lwoffii. Neither blaOXA-40/143- nor blaOXA-58-like genes were detected, and their origin remains therefore unknown. The phylogenetic tree analysis based on the alignment of the sequences deduced from blaADC revealed five main clusters, one containing ADC belonging to species closely related to A. baumannii and the others composed of cephalosporinases from the remaining species. No indication of blaOXA or blaADC transfer was observed between distantly related species, except for blaOXA-279, possibly transferred from Acinetobacter genomic species 6 to Acinetobacter parvus. Analysis of β-lactam susceptibility of seven strains harboring new oxacillinases and cloning of the corresponding genes in Escherichia coli and in a susceptible A. baumannii strain indicated very weak hydrolysis of carbapenems. Overall, this study reveals a large pool of β-lactamases in different Acinetobacter spp., potentially transferable to pathogenic strains of the genus.

Acinetobacter nectaris sp. nov. and Acinetobacter boissieri sp. nov., isolated from floral nectar of wild Mediterranean insect-pollinated plants

The taxonomic status of 14 strains of members of the genus Acinetobacter isolated from floral nectar of wild Mediterranean insect-pollinated plants, which did not belong to any previously described species within this genus, was investigated following a polyphasic approach. Confirmation that these strains formed two separate lineages within the genus Acinetobacter was obtained from comparative analysis of the partial sequences of the 16S rRNA gene and the gene encoding the β-subunit of RNA polymerase (rpoB), DNA–DNA reassociation data, determination of the DNA G+C content and physiological tests. The names Acinetobacter nectaris sp. nov. and Acinetobacter boissieri sp. nov. are proposed. The type strain of A. nectaris sp. nov. is SAP 763.2T ( = LMG 26958T = CECT 8127T) and that of A. boissieri sp. nov. is SAP 284.1T ( = LMG 26959T = CECT 8128T).

Acinetobacter puyangensis sp. nov., isolated from the healthy and diseased part of Populus xeuramericana canker bark

Two Gram-negative, non-motile, rod-shaped strains, BQ4-1(T) and NHI3-2, isolated respectively from the healthy and diseased part of Populus ×euramericana canker bark, were characterized using a polyphasic approach. Chemotaxonomic characterization supported the inclusion of the two strains in the genus Acinetobacter, with genomic DNA G+C contents (42.5-43 mol%) within the range observed for this genus (38-47 mol%) and 9-octadecenoic acid (C18 : 1ω9c, 39.87 %), hexadecanoic acid (C16 : 0, 11.26 %) and summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c, 18.90 %) as major fatty acids. Phylogenetic analysis based on 16S rRNA, rpoB and gyrB gene sequences revealed that strains BQ4-1(T) and NHI3 did not cluster with any species with validly published names, and formed a distinct cluster with 99-100 % bootstrap support on three phylogenetic trees within the genus Acinetobacter. Acid was not produced from d-glucose, and haemolysis was not observed on agar media supplemented with sheep erythrocytes. On the basis of phenotypic, genotypic and phylogenetic characteristics, the two strains are considered to represent a novel species of the genus Acinetobacter, for which the name Acinetobacter puyangensis sp. nov. is proposed. The type strain is BQ4-1(T) (= CFCC 10780(T) = JCM 18011(T)).

Complete genome sequence of bacteriophage phiAC-1 infecting Acinetobacter soli strain KZ-1

To date, a number of bacteriophages (phages) infecting Acinetobacter species have been reported and characterized. However, Acinetobacter phages which infect A. soli have not been investigated yet. Here, we report the complete genome sequence of Acinetobacter phage phiAC-1, which belongs to the Myoviridae, infecting Acinetobacter soli strain KZ-1.

Genetic diversity of endophytic diazotrophs of the wild rice, Oryza alta and identification of the new diazotroph, Acinetobacter oryzae sp. nov

Thirty-three endophytic diazotrophs were isolated from surface-sterilized leaves, stem, and roots of wild rice Oryza alta. The SDS-PAGE profile of total protein and insertion sequence-based polymerase chain reaction (IS-PCR) fingerprinting grouped the isolates into four clusters (I-IV). The 16S rRNA gene sequence homology of the representative strains B21, B31, B1, and B23 of clusters I, II, III, and IV were assigned to Pseudomonas oleovorans (99.2% similarity), Burkholderia fungorum (99.4% similarity), Enterobacter cloacae (98.9% similarity), and Acinetobacter johnsonii (98.4% similarity), respectively. The results showed wide genetic diversity of the putative diazotrophic strains of the wild rice, O. alta, and the strains of cluster IV are the first report of nitrogen-fixing Acinetobacter species. The cell size, phenotypic characters, total protein profile, genomic DNA fingerprinting, DNA-DNA hybridization, and antibiotic resistance differentiated strain B23(T) from its closest relatives A. johnsonii LMG999(T) and Acinetobacter haemolyticus LMG996(T). The DNA-DNA hybridization also distinguished the strain B23(T) from the closely related Acinetobacter species. Based on these data, a novel species, Acinetobacter oryzae sp. nov., and strain B23(T) (=LMG25575(T) = CGMCC1.10689(T)) as the type strain were proposed.

Acinetobacter indicus sp. nov., isolated from a hexachlorocyclohexane dump site

The taxonomic position of a Gram-negative, non-motile, oxidase negative and catalase positive strain, A648(T), isolated from a hexachlorocyclohexane (HCH) dump site located in Lucknow, India, was ascertained by using a polyphasic approach. A comparative analysis of a partial sequence of the rpoB gene and the 16S rRNA gene sequence revealed that strain A648(T) belonged to the genus Acinetobacter. DNA-DNA relatedness values between strain A648(T) and other closely related members (16S rRNA gene sequence similarity greater than 97%), namely Acinetobacter radioresistens DSM 6976(T), A. venetianus ATCC 31012(T), A. baumannii LMG 1041(T), A. parvus LMG 21765(T) A. junii LMG 998(T) and A. soli JCM 15062(T), were found to be less than 8%. The major cellular fatty acids of strain A648(T) were 18:1ω9c (19.6%), summed feature 3 (15.9%), 16:0 (10.6%) and 12:0 (6.4%). The DNA G+C content was 40.4 mol%. The polar lipid profile of strain A648(T) indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, followed by phosphatidylglycerol and phosphatidylcholine. The predominant polyamine of strain A648(T) was 1,3-diaminopropane and moderate amounts of putrescine, spermidine and spermine were also detected. The respiratory quinone consisted of ubiquinone with nine isoprene units (Q-9). On the basis of DNA-DNA hybridization, phenotypic characteristics and chemotaxonomic and phylogenetic comparisons with other members of the genus Acinetobacter, strain A648(T) is found to be a novel species of the genus Acinetobacter, for which the name Acinetobacter indicus sp. nov. is proposed. The type strain is A648(T) ( = DSM 25388(T) = CCM 7832(T)).

Acinetobacter: a potential reservoir and dispenser for β-lactamases

Innate resistance and remarkable ability to acquire additional resistance determinants underline the clinical importance of Acinetobacter. Over 210 β-lactamases belonging to 16 families have been identified in the genus, mostly in clinical isolates of A. baumannii. In this review, we update the current taxonomy of the genus Acinetobacter and summarize the β-lactamases detected in Acinetobacter spp. with an emphasis on Acinetobacter-derived cephalosporinases (ADCs) and carbapenem-hydrolysing class D β-lactamases (CHDLs). We also discuss the roles of integrons and insertion sequence (IS) elements in the expression and dissemination of such resistance determinants.

Acinetobacter soli as a cause of bloodstream infection in a neonatal intensive care unit

Acinetobacter soli is a new bacterial species described from forest soil. Five cases of bloodstream infection caused by A. soli clonal isolates are reported here for the first time. The patients were neonates admitted to an intensive care unit. This is a new neonatal pathogen with the potential to cause outbreaks.