scholarly journals Comparative Genomic Analysis and Phenotypic Characterization of Bronchoscope-associated Klebsiella aerogenes

Author(s):  
Fang Huang ◽  
Shuang Li ◽  
Xiaohui Chi ◽  
Peipei Wen ◽  
Hao Fu ◽  
...  

Abstract Background: Bronchoscopes has been linked to the outbreaks of nosocomial infections. We aim to investigate the phenotypic and genomic profiles of bronchoscope-associated Klebsiella aerogenes isolates, and their association with genome public available isolates from human and environment.Methods: We performed a prospective single-center study sampling echoendoscopes after clinical use and after normal decontamination procedures. Bacterial screening was conducted by culturing the sample on Mueller-Hinton agar plates. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing of K. aerogenes isolates was performed using an Illumina HiSeq system and comparative genomics analysis were conducted.Results: Over the 5-month period, a total of 358 isolates and 13 isolates were recovered from samples after clinical procedures and samples after decontamination procedures, respectively. Antimicrobial susceptibility testing found 7 K. aerogenes isolates to exhibit low-level resistance to antimicrobial agents. Among 7 K. aerogenes isolates, we found 5 sequence types (STs). Whole genome sequencing and comparison analysis observed the genetic diversity in our bacterial collection, which clustered into three main clades. Furthermore, we identified a total of 43 antimicrobial resistance genes in the K. aerogenes core genomes. As expected, human isolates encoded more antimicrobial resistance genes than that environmental isolates. Conclusions: This study first described the phenotypic and genomics characteristics of bronchoscope-associated K. aerogenes. The present observations demonstrated that broadly investigation of specific pathogens using publicly available global genomes offered the opportunity to identify prevalent clones associated with various hosts, sources, and geographical locations.

2020 ◽  
Author(s):  
Fang Huang ◽  
Shuang Li ◽  
Xiaohui Chi ◽  
Peipei Wen ◽  
Hao Fu ◽  
...  

Abstract Background: Bronchoscopes has been linked to the outbreaks of nosocomial infections. We aim to investigate the phenotypic and genomic profiles of bronchoscope-associated Klebsiella aerogenes isolates, and their association with genome public available isolates from human and environment.Methods: We performed a prospective single-center study sampling echoendoscopes after clinical use and after normal decontamination procedures. Bacterial screening was conducted by culturing the sample on Mueller-Hinton agar plates. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing of K. aerogenes isolates was performed using an Illumina HiSeq system and comparative genomics analysis were conducted.Results: Over the 5-month period, a total of 358 isolates and 13 isolates were recovered from samples after clinical procedures and samples after decontamination procedures, respectively. Antimicrobial susceptibility testing found 7 K. aerogenes isolates to exhibit low-level resistance to antimicrobial agents. Among 7 K. aerogenes isolates, we found 5 sequence types (STs). Whole genome sequencing and comparison analysis observed the genetic diversity in our bacterial collection, which clustered into three main clades. Furthermore, we identified a total of 43 antimicrobial resistance genes in the K. aerogenes core genomes. As expected, human isolates encoded more antimicrobial resistance genes than that environmental isolates. Conclusions: This study first described the phenotypic and genomics characteristics of bronchoscope-associated K. aerogenes. The present observations demonstrated that broadly investigation of specific pathogens using publicly available global genomes offered the opportunity to identify prevalent clones associated with various hosts, sources, and geographical locations.


2020 ◽  
Vol 11 ◽  
Author(s):  
Grazielle Lima Rodrigues ◽  
Pedro Panzenhagen ◽  
Rafaela Gomes Ferrari ◽  
Anamaria dos Santos ◽  
Vania Margaret Flosi Paschoalin ◽  
...  

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1131
Author(s):  
Noel Gahamanyi ◽  
Dae-Geun Song ◽  
Kye-Yoon Yoon ◽  
Leonard E. G. Mboera ◽  
Mecky I. Matee ◽  
...  

Thermophilic Campylobacter species of poultry origin have been associated with up to 80% of human campylobacteriosis cases. Layer chickens have received less attention as possible reservoirs of Campylobacter species. Initially, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of two archived Campylobacter isolates (Campylobacter jejuni strain 200605 and Campylobacter coli strain 200606) from layer chickens to five antimicrobials (ciprofloxacin, nalidixic acid, erythromycin, tetracycline, and gentamicin) were determined using broth microdilution while the presence of selected antimicrobial resistance genes was performed by polymerase chain reaction (PCR) using specific primers. Whole-genome sequencing (WGS) was performed by the Illumina HiSeq X platform. The analysis involved antimicrobial resistance genes, virulome, multilocus sequence typing (MLST), and phylogeny. Both isolates were phenotypically resistant to ciprofloxacin (MIC: 32 vs. 32 µg/mL), nalidixic acid (MIC: 128 vs. 64 µg/mL), and tetracycline (MIC: 64 vs. 64 µg/mL), but sensitive to erythromycin (MIC: 1 vs. 2 µg/mL) and gentamicin (MIC: 0.25 vs. 1 µg/mL) for C. jejuni strain 200605 and C. coli strain 200606, respectively. WGS confirmed C257T mutation in the gyrA gene and the presence of cmeABC complex conferring resistance to FQs in both strains. Both strains also exhibited tet(O) genes associated with tetracycline resistance. Various virulence genes associated with motility, chemotaxis, and capsule formation were found in both isolates. However, the analysis of virulence genes showed that C. jejuni strain 200605 is more virulent than C. coli strain 200606. The MLST showed that C. jejuni strain 200605 belongs to sequence type ST-5229 while C. coli strain 200606 belongs to ST-5935, and both STs are less common. The phylogenetic analysis clustered C. jejuni strain 200605 along with other strains reported in Korea (CP028933 from chicken and CP014344 from human) while C. coli strain 200606 formed a separate cluster with C. coli (CP007181) from turkey. The WGS confirmed FQ-resistance in both strains and showed potential virulence of both strains. Further studies are recommended to understand the reasons behind the regional distribution (Korea, China, and Vietnam) of such rare STs.


Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 686
Author(s):  
Poonam Sharma ◽  
Sushim K. Gupta ◽  
John B. Barrett ◽  
Lari M. Hiott ◽  
Tiffanie A. Woodley ◽  
...  

Enterococcus cecorum is an emerging avian pathogen, particularly in chickens, but can be found in both diseased (clinical) and healthy (non-clinical) poultry. To better define differences between E. cecorum from the two groups, whole-genome sequencing (WGS) was used to identify and compare antimicrobial resistance genes as well as the pan-genome among the isolates. Eighteen strains selected from our previous study were subjected to WGS using Illumina MiSeq and comparatively analyzed. Assembled contigs were analyzed for resistance genes using ARG-ANNOT. Resistance to erythromycin was mediated by ermB, ermG, and mefA, in clinical isolates and ermB and mefA, in non-clinical isolates. Lincomycin resistance genes were identified as linB, lnuB, lnuC, and lnuD with lnuD found only in non-clinical E. cecorum; however, lnuB and linB were found in only one clinical isolate. For both groups of isolates, kanamycin resistance was mediated by aph3-III, while tetracycline resistance was conferred by tetM, tetO, and tetL. No mutations or known resistance genes were found for isolates resistant to either linezolid or chloramphenicol, suggesting possible new mechanisms of resistance to these drugs. A comparison of WGS results confirmed that non-clinical isolates contained more resistance genes than clinical isolates. The pan-genome of clinical and non-clinical isolates resulted in 3651 and 4950 gene families, respectively, whereas the core gene sets were comprised of 1559 and 1534 gene families in clinical and non-clinical isolates, respectively. Unique genes were found more frequently in non-clinical isolates than clinical. Phylogenetic analysis of the isolates and all the available complete and draft genomes showed no correlation between healthy and diseased poultry. Additional genomic comparison is required to elucidate genetic factors in E. cecorum that contribute to disease in poultry.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yanyan Zhang ◽  
Danxia Gu ◽  
Xuemei Yang ◽  
Yuchen Wu ◽  
Congcong Liu ◽  
...  

A rectal swab sample was collected from a patient with Guillain–Barré syndrome and enriched in lysogeny broth. Carbapenem-resistant bacteria were selected by China Blue agar plates containing 0.3 μg/ml meropenem. Carbapenemase-producing Klebsiella michiganensis was identified and characterized by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), immune colloidal gold technique, a conjugation experiment, PCR analysis, and antimicrobial susceptibility testing. The genome of K. michiganensis was determined by whole genome sequencing. Antimicrobial susceptibility testing showed that the K. michiganensis was resistant to imipenem, meropenem, ertapenem, cefmetazole, ceftazidime, cefotaxime, piperacillin/tazobactam, sulbactam/cefoperazone, ceftazidime/avibactam, cefepime, and aztreonam while susceptible to polymyxin B, ciprofloxacin, tigecycline, and amikacin. Immune colloidal gold technique suggested that this strain co-produced three different carbapenemases [Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-beta-lactamase (NDM), and Imipenem (IMP)]. Whole genome sequencing analysis indicated that this strain belonged to ST91, and blaKPC–2, blaNDM–1, and blaIMP–4 were carried on different conjugative plasmids. Besides, the co-existence and transferability of blaKPC–2, blaNDM–1, and blaIMP–4 in K. michiganensis facilitates the potential horizontal dissemination and nosocomial spread of resistance genes among multidrug-resistant organisms.


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