scholarly journals Identification of antibiotic-producing Bacillus sensu lato isolated from national parks of Hoang Lien and Phu Quoc in Vietnam

2014 ◽  
Vol 6 (1) ◽  
pp. 77-83
Author(s):  
Thi Tuyet Van Dinh ◽  
Nguyen Hai Linh Bui ◽  
Van Hop Duong ◽  
Mai Phuong Doan ◽  
Thanh Trung Trinh

Many lipopeptide antibiotics produced from Bacillus sensu lato (Bacillus s. l.) against drug-resistant bacteria have been recently reported. To explore the potential production of the antibiotics from this group of bacteria in Vietnam, we collected 38 soil samples from two national parks of Hoang Lien and Phu Quoc and isolated 411Bacillus s. l. strains. Of those, 22 strains had antagonistic activity against both susceptible S. aureus and E. coli. The strains were further tested on drug-resistant bacteria collected at Bach Mai hospital and 20 strains demonstrated antagonistic activity against at least 2 of 18 drug-resistant bacteria K. pneumoniae, E. coli, A. baumannii and S. aureus. Analysis of 16S rDNA sequence showed that most of the broad spectrum antibiotic producers were Paenibacillus species whereas narrow spectrum antibiotic producers were Bacillus species. Strains PQH 0103 and PQH 0410 were probably produced novel antibiotic agents as they suspected to be novel taxa in Paenibacillus genus. Moreover, strains PQH 1509 and PQH 1702 produced broad spectrum antibiotics were identified as P. chitinolyticus. To our best knowledge, there is no report on antibiotic production from this species. Further elucidation of chemical structure of antibiotics produced from Bacillus s. l. isolated in soils of Vietnam is needed. Gần đây, nhiều kháng sinh lipopeptide từ vi khuẩn Bacillus sensu lato (Bacillus s. l.) có khả năng sinh kháng sinh kháng vi khuẩn kháng thuốc đã được phát hiện và công bố. Để tìm hiểu khả năng sinh kháng sinh của nhóm vi khuẩn này ở Việt Nam, chúng tôi tiến hành thu thập 38 mẫu đất tại vườn Quốc gia Hoàng Liên và vườn Quốc gia Phú Quốc và phân lập được 411 chủng vi khuẩn Bacillus s. l.. Trong số đó, 22 chủng có khả năng sinh kháng sinh kháng 2 chủng vi khuẩn S. aureus và E. coli nhậy cảm thuốc. 20 trong số 22 chủng này có hoạt tính kháng ít nhất từ 2 đến 18 chủng kiểm định kháng thuốc thuộc các loài K. pneumoniae, E. coli, A. baumannii và S. aureus. Dựa trên kết quả phân loại bằng trình tự gene 16S rRNA, các chủng Bacillus s. l. sinh kháng sinh phổ rộng là các loài Paenibacillus trong khi đó các loài sinh kháng sinh phổ hẹp là Bacillus. Trên cây phát sinh chủng loại, chủng PQH 0103 và PQH 0410 có thể là những loài mới và có tiềm năng sinh các chất kháng sinh mới. Hơn nữa, chủng PQH 1509 và PQH 1702 sinh kháng sinh phổ rộng được phân loại vào loài P. chitinolyticus. Đây là loài chưa có công bố nào về khả năng sinh chất kháng sinh và có thể là loài sinh chất kháng sinh mới. Nghiên cứu giải mã cấu trúc chất kháng sinh từ các loài Bacillus s. l. phân lập tại Việt Nam cần được làm rõ trong tương lai.

2011 ◽  
Vol 56 (3) ◽  
pp. 1414-1417 ◽  
Author(s):  
Jien-Wei Liu ◽  
Wen-Chien Ko ◽  
Cheng-Hua Huang ◽  
Chun-Hsing Liao ◽  
Chin-Te Lu ◽  
...  

ABSTRACTThe TigecyclineIn VitroSurveillance in Taiwan (TIST) study, initiated in 2006, is a nationwide surveillance program designed to longitudinally monitor thein vitroactivity of tigecycline against commonly encountered drug-resistant bacteria. This study compared thein vitroactivity of tigecycline against 3,014 isolates of clinically important drug-resistant bacteria using the standard broth microdilution and disk diffusion methods. Species studied included methicillin-resistantStaphylococcus aureus(MRSA;n= 759), vancomycin-resistantEnterococcus faecium(VRE;n= 191), extended-spectrum β-lactamase (ESBL)-producingEscherichia coli(n= 602), ESBL-producingKlebsiella pneumoniae(n= 736), andAcinetobacter baumannii(n= 726) that had been collected from patients treated between 2008 and 2010 at 20 hospitals in Taiwan. MICs and inhibition zone diameters were interpreted according to the currently recommended U.S. Food and Drug Administration (FDA) criteria and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The MIC90values of tigecycline against MRSA, VRE, ESBL-producingE. coli, ESBL-producingK. pneumoniae, andA. baumanniiwere 0.5, 0.125, 0.5, 2, and 8 μg/ml, respectively. The total error rates between the two methods using the FDA criteria were high: 38.4% for ESBL-producingK. pneumoniaeand 33.8% forA. baumannii. Using the EUCAST criteria, the total error rate was also high (54.6%) forA. baumanniiisolates. The total error rates between these two methods were <5% for MRSA, VRE, and ESBL-producingE. coli. For routine susceptibility testing of ESBL-producingK. pneumoniaeandA. baumanniiagainst tigecycline, the broth microdilution method should be used because of the poor correlation of results between these two methods.


2021 ◽  
Author(s):  
Yingxue Deng ◽  
Rui Huang ◽  
Songyin Huang ◽  
Menghua Xiong

Antimicrobial peptides (AMPs) have emerged as promising alternatives of traditional antibiotics against drug-resistant bacteria owing to their broad-spectrum antimicrobial properties and low tendency to drugresistance. However, their therapeutic efficacy in vivo, especially for infections in deep organs, is limited owing to their systemic toxicity and low bioavailability. Nanoparticles-based delivery systems offer a strategy to increase the therapeutic index of AMPs by preventing proteolysis, increasing the accumulation at infection sites, and reducing toxicity. Herein, we will discuss the current progress of using nanoparticles as delivery vehicles for AMPs for the treatment of deep infections.


2011 ◽  
Vol 56 (3) ◽  
pp. 1452-1457 ◽  
Author(s):  
Yen-Hsu Chen ◽  
Po-Liang Lu ◽  
Cheng-Hua Huang ◽  
Chun-Hsing Liao ◽  
Chin-Te Lu ◽  
...  

ABSTRACTThe TigecyclineIn VitroSurveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistantStaphylococcus aureus(MRSA) (n= 1,834), penicillin-resistantStreptococcus pneumoniae(PRSP) (n= 423), vancomycin-resistant enterococci (VRE) (n= 219), extended-spectrum β-lactamase (ESBL)-producingEscherichia coli(n= 1,141), ESBL-producingKlebsiella pneumoniae(n= 1,330),Acinetobacter baumannii(n= 1,645), andStenotrophomonas maltophilia(n= 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC90, 0.03 μg/ml), and only one MRSA isolate (MIC90, 0.5 μg/ml) and three VRE isolates (MIC90, 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producingE. coli(MIC90, 0.5 μg/ml) and 96.32% for ESBL-producingK. pneumoniae(MIC90, 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate forA. baumannii(MIC90, 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptibleA. baumanniiisolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptibleA. baumanniiisolates. In Taiwan, tigecycline continues to have excellentin vitroactivity against several major clinically important drug-resistant bacteria, with the exception ofA. baumannii.


2021 ◽  
Vol 6 (3) ◽  
pp. 123
Author(s):  
Aikaterini Moschou ◽  
Petros Ioannou ◽  
Eleni Moraitaki ◽  
Dimitra Stafylaki ◽  
Sofia Maraki ◽  
...  

(1) Background: In an area with a high prevalence of multi-drug resistant Gram-negative bacteria (MDR-GNB), we investigated the colonization of nursing home residents by such organisms. (2) Methods: A point prevalence study was performed in six nursing homes of the Heraklion area on the island of Crete. A rectal swab was taken and cultured from each participant, while additional risk factors such as recent hospitalization or antimicrobial usage were recorded and evaluated. (3) Results: A total of 137 nursing home residents were included in the study. Their mean age was 82.1 years and 19.7% were males. In total, cultures yielded 255 GNB; E. coli, K. pneumoniae and P. aeruginosa were the most common. Among the microorganisms cultured, 17.6% had the extended-spectrum beta-lactamase phenotype, while 18% were MDR. A statistically significant association was found between recent antimicrobial use and colonization by MDR-GNB; (4) Conclusions: Colonization by MDR-GNB was found to be highly prevalent in nursing home residents. Recent antimicrobial use was associated with MDR-GNB carriage.


2021 ◽  
Vol 13 (2) ◽  
pp. 222
Author(s):  
Delianis Pringgenies ◽  
Wilis Ari Setyati ◽  
Ali Djunaedi ◽  
Rini Pramesti ◽  
Siti Rudiyanti ◽  
...  

Highlight ResearchAntimicrobial potential against the test microbesRhizhopora mucronata isolate showed 95% homology with Bacillus subtilis, and 97% homology with Bacillus oceanisediminis,Acanthus ilicifolius isolate showed 96% homology with Paracoccus caeni, and 89% homology with Bacillus circulans. The study found 4 isolates with antimicrobial potency against MDR pathogenic microbes.The symbiont microbes taken from Rhizophora mucronata and Acanthus ilicifolius were determined to be of the genus Bacillus and Paracoccus AbstractAntimicrobial property of mangrove symbiont have the ability to fight Multi Drug Resistant bacteria which were Staphylococcus aureus, Escherichia coli, and Vibrio haryeyi. This study aimed to determine the potential of symbiont microbes from the root of Rhizopora mucronata and Acanthus iilicifolius as antimicrobial agents against multi-drug resistant (MDR) pathogenic microbes. This research was conducted during July to November 2020. The MDR bacteria were S. aureus, E. coli, and V. harveyi MDR test microbes. The symbiont microbes were identified through molecular analyses (PCR 16S rDNA). Isolation of symbiont microbes from R. mucronata resulted in 16 isolates, while isolation from A. iilicifolius resulted in 14 isolates. Based on the antimicrobial qualitative test against S. aureus, 8 out of 16 microbial isolates from R. mucronata were found to show antimicrobial properties. The testing of A. ilicifolius symbiont microbes against S. aureus showed 8 out of 14 isolates with antimicrobial properties. The test against E. coli resulted in 2 out of 16 microbial isolates from R. mucronata and 5 out of 14 isolates from A. ilicifolius with antimicrobial properties. The test against V. harveyi resulted in two out of 16 microbial isolates from R.mucronata and 4 out of 14 isolates from A. ilicifolius with antimicrobial properties. The quantitative test found 2 isolates from R. mucronta, namely isolates RM10 and RM12, with antimicrobial properties against MDR strain E. coli, with the best isolate being RM10, which produced 11.22 mm of inhibition zone diameter. Furthermore, the selection of isolates was based on the size of the inhibition zone, the clearness of the inhibition zone and the potential for antibacterial activity. Based on their overall antimicrobial potential against the test microbes, four isolates were selected.  Molecular analyses of RM12 isolate showed 95% homology with Bacillus subtilis, of RM 10 isolate showed 97% homology with Bacillus oceanisediminis, of AC isolate showed 96% homology with Paracoccus caeni, and of AC 5 isolate showed 89% homology with Bacillus circulans. The study found four isolates with antimicrobial potency against MDR pathogenic microbes. The symbiont microbes taken from R. mucronata and A. ilicifolius were determined to be of the genus Bacillus and Paracoccus. 


CCS Chemistry ◽  
2021 ◽  
pp. 1-32
Author(s):  
Ke Xue ◽  
Cuihong Yang ◽  
Chun Wang ◽  
Yang Liu ◽  
Jianfeng Liu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document