scholarly journals Genomic insights into the circulation of pandemic fluoroquinolone-resistant extra-intestinal pathogenic Escherichia coli ST1193 in Vietnam

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Quynh Nguyen ◽  
To Thi Nguyen Nguyen ◽  
Phuong Pham ◽  
Vinh Chau ◽  
Lan Phu Huong Nguyen ◽  
...  

Extra-intestinal pathogenic Escherichia coli (ExPEC) ST1193, a globally emergent fluoroquinolone-resistant clone, has become an important cause of bloodstream infections (BSIs) associated with significant morbidity and mortality. Previous studies have reported the emergence of fluoroquinolone-resistant ExPEC ST1193 in Vietnam; however, limited data exist regarding the genetic structure, antimicrobial resistance (AMR) determinants and transmission dynamics of this pandemic clone. Here, we performed genomic and phylogenetic analyses of 46 ST1193 isolates obtained from BSIs and healthy individuals in Ho Chi Minh City, Vietnam, to investigate the pathogen population structure, molecular mechanisms of AMR and potential transmission patterns. We further examined the phylogenetic structure of ST1193 isolates in a global context. We found that the endemic E. coli ST1193 population was heterogeneous and highly dynamic, largely driven by multiple strain importations. Several well-supported phylogenetic clusters (C1–C6) were identified and associated with distinct bla CTX-M variants, including bla CTXM-27 (C1–C3, C5), bla CTXM-55 (C4) and bla CTXM-15 (C6). Most ST1193 isolates were multidrug-resistant and carried an extensive array of AMR genes. ST1193 isolates also exhibited the ability to acquire further resistance while circulating in Vietnam. There were phylogenetic links between ST1193 isolates from BSIs and healthy individuals, suggesting these organisms may both establish long-term colonization in the human intestinal tract and induce infections. Our study uncovers factors shaping the population structure and transmission dynamics of multidrug-resistant ST1193 in Vietnam, and highlights the urgent need for local One Health genomic surveillance to capture new emerging ExPEC clones and to better understand the origins and transmission patterns of these pathogens.

Microbiology ◽  
2021 ◽  
Vol 167 (6) ◽  
Author(s):  
Priyanka ◽  
Prem Raj Meena ◽  
Keshav Kumar Meghwanshi ◽  
Anuj Rana ◽  
Arvind Pratap Singh

A continued rise in leafy green-linked outbreaks of disease caused by pathogenic Escherichia coli or Salmonella , particularly strains exhibiting multidrug resistance (MDR), has emerged as a major threat to human health and food safety worldwide. Thus, the present study was conducted to examine antimicrobial resistance, including MDR, in diarrhoeagenic E. coli (DEC) and Salmonella isolates obtained from leafy greens from rural and urban areas of India. Of the collected samples (830), 14.1 and 6.5% yielded 117 E. coli (40 DEC and 77 non-DEC) and 54 Salmonella isolates, respectively. Among the DEC pathotypes, enteroaggregative E. coli was the most prevalent (10.2 %), followed by enteropathogenic E. coli (9.4 %), enteroinvasive E. coli (7.6 %) and enterohemorrhagic E. coli (6.8 %). Antimicrobial susceptibility testing of all bacterial isolates with respect to drugs categorized as critically or highly important in both human and veterinary medicine revealed moderate to high (30–90%) resistance for amoxicillin/clavulanic acid, ampicillin, gentamycin and colistin, but relatively low resistance (>30 %) for ciprofloxacin, trimethoprim/sulfamethoxazole and fosfomycin. Notably, all DEC and more than 90% non-DEC or Salmonella isolates were found to be multidrug-resistant to drugs of both human and animal importance. Overall, the results of the present study suggest that leafy greens are potential reservoirs or sources of multidrug-resistant DEC and Salmonella strains in the rural or urban areas of India.


2021 ◽  
Vol 70 (11) ◽  
Author(s):  
Lii-Tzu Wu ◽  
Xin-Xia Wu ◽  
Se-Chin Ke ◽  
Yi-Pei Lin ◽  
Ying-Chen Wu ◽  
...  

Introduction. Antimicrobial resistance associated with animal hosts is easily transmitted to humans either by direct contact with resistant organisms or by transferring resistance genes into human pathogens. Gap statement. There are limited studies on antimicrobial resistance genes and genetic elements of multidrug-resistant (MDR) Escherichia coli in veterinary hospitals in Taiwan. Aim. The aim of this study was to investigate antimicrobial resistance genes in multidrug-resistant Escherichia coli from animals. Methodology. Between January 2014 and August 2015, 95 multidrug-resistant Escherichia coli isolates were obtained from pigs (n=66), avians (n=18), and other animals (n=11) in a veterinary hospital in Taiwan. Susceptibility testing to 24 antimicrobial agents of 14 antimicrobial classes was performed. Antimicrobial resistance genes, integrons, and insertion sequences were analysed by polymerase chain reaction and nucleotide sequencing. Pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing were used to explore the clonal relatedness of the study isolates. Results. Different antimicrobial resistance genes found in these isolates were associated with resistance to β-lactams, tetracycline, phenicols, sulfonamides, and aminoglycosides. Fifty-five of 95 E. coli isolates (55/95, 57.9 %) were not susceptible to extended-spectrum cephalosporins, and bla CTX-M-55 (11/55, 20.0 %) and bla CMY-2 (40/55, 72.7 %) were the most common extended-spectrum β-lactamase (ESBL) and AmpC genes, respectively. Both bla CTX-M and bla CMY-2 were present on conjugative plasmids that contained the insertion sequence ISEcp1 upstream of the bla genes. Plasmid-mediated FOX-3 β-lactamase-producing E. coli was first identified in Taiwan. Forty isolates (40/95, 42 %) with class 1 integrons showed seven resistance phenotypes. Genotyping of 95 E. coli isolates revealed 91 different XbaI pulsotypes and 52 different sequence types. PFGE analysis revealed no clonal outbreaks in our study isolates. Conclusion. This study showed a high diversity of antimicrobial resistance genes and genotypes among MDR E. coli isolated from diseased livestock in Taiwan. To our knowledge, this is the first report of plasmid-mediated ESBL in FOX-3 β-lactamase-producing E. coli isolates in Taiwan. MDR E. coli isolates from animal origins may contaminate the environment, resulting in public health concerns, indicating that MDR isolates from animals need to be continuously investigated.


2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Lijuan Luo ◽  
Hong Wang ◽  
Michael J. Payne ◽  
Chelsea Liang ◽  
Li Bai ◽  
...  

Escherichia albertii is a recently recognized species in the genus Escherichia that causes diarrhoea. The population structure, genetic diversity and genomic features have not been fully examined. Here, 169 E. albertii isolates from different sources and regions in China were sequenced and combined with 312 publicly available genomes (from additional 14 countries) for genomic analyses. The E. albertii population was divided into two clades and eight lineages, with lineage 3 (L3), L5 and L8 more common in China. Clinical isolates were observed in all clades/lineages. Virulence genes were found to be distributed differently among lineages: subtypes of the intimin encoding gene eae and the cytolethal distending toxin gene cdtB were lineage associated, and the second type three secretion system (ETT2) island was truncated in L3 and L6. Seven new eae subtypes and one new cdtB subtype (cdtB-VI) were identified. Alarmingly, 85.9 % of the Chinese E. albertii isolates were predicted to be multidrug-resistant (MDR) with 35.9 % harbouring genes capable of conferring resistance to 10 to 14 different drug classes. The majority of the MDR isolates were of poultry source from China and belonged to four sequence types (STs) [ST4638, ST4479, ST4633 and ST4488]. Thirty-four plasmids with some carrying MDR and virulence genes, and 130 prophages were identified from 17 complete E. albertii genomes. The 130 intact prophages were clustered into five groups, with group five prophages harbouring more virulence genes. We further identified three E. albertii specific genes as markers for the identification of this species. Our findings provided fundamental insights into the population structure, virulence variation and drug resistance of E. albertii .


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 516-521 ◽  
Author(s):  
Gaiyun Zhang ◽  
Yubian Zhang ◽  
Xijie Yin ◽  
Shuang Wang

A Gram-staining-positive, aerobic, motile and non-spore-forming actinobacteria, designated strain F10T, was isolated from a deep-sea sediment of the western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Nesterenkonia . Strain F10T shared highest 16S rRNA gene sequence similarity of 96.8 % with Nesterenkonia aethiopica DSM 17733T, followed by Nesterenkonia xinjiangensis YIM 70097T (96.7 %) and Nesterenkonia alba CAAS 252T (96.6 %). The organism grew at 4–50 °C, at pH 7.0–12.0 and in the presence of 0–12 % (w/v) NaCl, with optimal growth occurring at 40 °C, at pH 9.0 and in the presence of 1 % (w/v) NaCl. The peptidoglycan type was A4(alpha), l-Lys–Gly–l-Glu. The polar lipid profile of strain F10T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and two unknown lipids. The isolate contained MK-9 (92 %) and MK-8 (5.8 %) as the major components of the menaquinone system, and anteiso-C17 : 0 (50.9 %) and anteiso-C15 : 0 (29.8 %) as the predominant fatty acids. The G+C content of the genomic DNA of strain F10T was 66.2 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain F10T represents a novel species of the genus Nesterenkonia for which the name Nesterenkonia alkaliphila sp. nov. is proposed. The type strain is F10T ( = LMG 28112T = CGMCC 1.12781T = JCM 19766T = MCCC 1A09946T).


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 934-938 ◽  
Author(s):  
Wen-Ming Chen ◽  
Rey-Chang Chang ◽  
Chih-Yu Cheng ◽  
Yu-Wen Shiau ◽  
Shih-Yi Sheu

A novel bacterium, designated strain JchiT, was isolated from soil in Taiwan and characterized using a polyphasic approach. Cells of strain JchiT were aerobic, Gram-stain-negative, motile and rod-shaped. They contained poly-β-hydroxybutyrate granules and formed dark-yellow colonies. Growth occurred at 20–37 °C (optimum between 25 and 30 °C), at pH 6.0–8.0 (optimum between pH 7.0 and pH 8.0) and with 0–2 % NaCl (optimum between 0 and 1 %). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain JchiT belonged to the genus Jeongeupia and that its closest neighbour was Jeongeupia naejangsanensis BIO-TAS4-2T (98.0 % sequence similarity). The major fatty acids (>10 %) of strain JchiT were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major cellular hydroxy fatty acid was C12 : 0 3-OH. The isoprenoid quinone was Q-8 and the genomic DNA G+C content was 66.1 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine and two unidentified phospholipids. The DNA–DNA relatedness value between strain JchiT and J. naejangsanensis BIO-TAS4-2T was about 41.0 %. On the basis of the genotypic and phenotypic data, strain JchiT represents a novel species in the genus Jeongeupia , for which the name Jeongeupia chitinilytica sp. nov. is proposed. The type strain is JchiT ( = BCRC 80367T  = KCTC 23701T).


Author(s):  
Fenfa Li ◽  
Qingyi Xie ◽  
Shuangqing Zhou ◽  
Fandong Kong ◽  
Yun Xu ◽  
...  

Strain HNM0947T, representing a novel actinobacterium, was isolated from the coral Galaxea astreata collected from the coast of Wenchang, Hainan, China. The strain was found to have morphological and chemotaxonomic characteristics consistent with the genus Nocardiopsis . The organism formed abundant fragmented substrate mycelia and aerial mycelia which differentiated into non-motile, rod-shaped spores. Whole-cell hydrolysates contained meso-diaminopimelic acid and no diagnostic sugars. The major menaquinones were MK-10(H8), MK-10(H6) and MK-10(H4). The major phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were iso-C16:0, anteiso-C17:0, C18:0, C18:0 10-methyl (TBSA) and anteiso-C15:0. The G+C content was 71.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HNM0947T belonged to the genus Nocardiopsis and shared highest sequence similarity to Nocardiopsis salina YIM 90010T (98.8%), Nocardiopsis xinjiangensis YIM 90004T(98.5%) and Nocardiopsis kunsanensis DSM 44524T (98.3%). The strain HNM0947T was distinguished from its closest type strain by low average nucleotide identity (90.8%) and dDDH values (60.4%) respectively. Based on genotypic, chemotaxonomic and phenotypic characteristics, it was concluded that strain HNM0947T represents a novel species of the genus Nocardiopsis whose name was proposed as Nocardiopsis coralli sp. nov. The type strain was HNM0947T (=CCTCC AA 2020015 T=KCTC 49525 T).


Author(s):  
Shan Jiang ◽  
Feng-Bai Lian ◽  
You-Yang Sun ◽  
Xiao-Kui Zhang ◽  
Zong-Jun Du

A Gram-stain-negative, rod-shaped and facultatively aerobic bacterial strain, designated F7430T, was isolated from coastal sediment collected at Jingzi Wharf in Weihai, PR China. Cells of strain F7430T were 0.3–0.4 µm wide, 2.0–2.6 µm long, non-flagellated, non-motile and formed pale-beige colonies. Growth was observed at 4–40 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, pH 7.5–8.0) and at NaCl concentrations of 1.0–10.0 % (w/v; optimum, 1.0 %). The sole respiratory quinone of strain F7430T was ubiquinone 8 and the predominant cellular fatty acids were summed feature 8 (C18 : 1  ω7c / C18 : 1  ω6c; 60.7 %), summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c; 30.2 %) and C15 : 0 iso (13.9 %). The polar lipids of strain F7430T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid and three unidentified lipids. Results of 16S rRNA gene sequences analyses indicated that this strain belonged to the family Halieaceae and had high sequence similarities to Parahaliea aestuarii JCM 51547T (95.3 %) and Halioglobus pacificus DSM 27932T (95.2 %) followed by 92.9–95.0 % sequence similarities to other type species within the aforementioned family. The rpoB gene sequences analyses indicated that the novel strain had the highest sequence similarities to Parahaliea aestuarii JCM 51547T (82.2 %) and Parahaliea mediterranea DSM 21924T (82.2 %) followed by 75.2–80.5 % sequence similarities to other type species within this family. Phylogenetic analyses showed that strain F7430T constituted a monophyletic branch clearly separated from the other genera of family Halieaceae . Whole-genome sequencing of strain F7430T revealed a 3.3 Mbp genome size with a DNA G+C content of 52.6 mol%. The genome encoded diverse metabolic pathways including the Entner–Doudoroff pathway, assimilatory sulphate reduction and biosynthesis of dTDP-l-rhamnose. Based on results from the current polyphasic study, strain F7430T is proposed to represent a novel species of a new genus within the family Halieaceae , for which the name Sediminihaliea albiluteola gen. nov., sp. nov. is proposed. The type strain of the type species is F7430T (=KCTC 72873T=MCCC 1H00420T).


Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.


Author(s):  
Silvio Hering ◽  
Moritz K. Jansson ◽  
Michael E. J. Buhl

A novel species within the genus Eikenella is described, based on the phenotypical, biochemical and genetic characterization of a strain of a facultatively anaerobic, Gram-negative rod-shaped bacterium. Strain S3360T was isolated from the throat swab of a patient sampled during routine care at a hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequences) placed the strain in the genus Eikenella , separate from all recognized species but with the closest relationship to Eikenella longinqua (NML 02-A-017T). Eikenella is one of the genera in the HACEK group known to be responsible for rare cases of endocarditis in humans. Until the recent descriptions of Eikenella exigua , Eikenella halliae and Eikenella longinqua , Eikenella corrodens had been the only validly published species in this genus since its description as Bacteroides corrodens in 1958. Unlike these species, strain S3360T is able to metabolize carbohydrates (glucose). The average nucleotide identities of strain S3360T with E. longinqua (NML 02-A-017T) and E. corrodens (NCTC 10596T), the type species of the genus, were 90.5 and 84.7 %, respectively, and the corresponding genome-to-genome distance values were 41.3 and 29.0 %, respectively. The DNA G+C content of strain S3360T was 58.4 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3360T is considered to represent a novel species within the genus Eikenella , for which the name Eikenella glucosivorans sp. nov. is proposed. The type strain is S3360T (DSM 110714T=CCOS 1935T=CCUG 74293T). In addition, an emendation of the genus Eikenella is proposed to include species which are saccharolytic.


Author(s):  
Caixin Yang ◽  
Yibo Bai ◽  
Kui Dong ◽  
Jing Yang ◽  
Xin-He Lai ◽  
...  

Four Gram-stain-positive, catalase-negative, non-spore-forming, rod-shaped bacterial strains (zg-325T, zg329, dk561T and dk752) were isolated from the respiratory tract of marmot (Marmota himalayana) and the faeces of Tibetan gazelle (Procapra picticaudata) from the Qinghai-Tibet Plateau of PR China. The results of 16S rRNA gene sequence-based phylogenetic analyses indicated that strains zg-325T and dk561T represent members of the genus Actinomyces , most similar to Actinomyces denticolens DSM 20671T and Actinomyces ruminicola B71T, respectively. The DNA G+C contents of strains zg-325T and dk561T were 71.6 and 69.3 mol%, respectively. The digital DNA–DNA hybridization values of strains zg-325T and dk561T with their most closely related species were below the 70 % threshold for species demarcation. The four strains grew best at 35 °C in air containing 5 % CO2 on brain heart infusion (BHI) agar with 5 % sheep blood. All four strains had C18:1ω9c and C16:0 as the major cellular fatty acids. MK-8 and MK-9 were the major menaquinones in zg-325T while MK-10 was predominant in dk561T. The major polar lipids included diphosphatidylglycerol and phosphatidylinositol. On the basis of several lines of evidence from phenotypic and phylogenetic analyses, zg-325T and dk561T represent novel species of the genus Actinomyces , for which the name Actinomyces marmotae sp. nov. and Actinomyces procaprae sp. nov. are proposed. The type strains are zg-325T (=GDMCC 1.1724T=JCM 34091T) and dk561T (=CGMCC 4.7566T=JCM 33484T). We also propose, on the basis of the phylogenetic results herein, the reclassification of Actinomyces liubingyangii and Actinomyces tangfeifanii as Boudabousia liubingyangii comb. nov. and Boudabousia tangfeifanii comb. nov., respectively.


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