scholarly journals Antibiograms and Molecular Characterization of Drug Resistance of Mycobacterium abscessus complex from Patients with Multidrug-Resistant Pulmonary Tuberculosis (MDR TB) Infection

2019 ◽  
Author(s):  
Kenneth A. Bongulto ◽  
Concepcion F. Ang ◽  
Esperanza C. Cabrera
Keyword(s):  
Point Mutations ◽  
Multidrug Resistant ◽  
The Philippines ◽  
Mycobacterium Abscessus ◽  
Broth Microdilution ◽  
Inducible Resistance ◽  
Mycobacterium Abscessus Complex ◽  
Sputum Microscopy ◽  
Mdr Tb

ABSTRACTIn the Philippines, acid fast bacilli positive sputum samples commonly treated as TB due to Mycobacterium tuberculosis (MTB) complex. However, Mycobacterium abscessus (MAB) complex is often found in MTB cultures, or in patients confirmed negative for TB through sputum microscopy and culture. Hence, patients with MAB infections are mistakenly prescribed six-month anti-TB treatments. In this study, MAB complex isolates from MDRTB patients were identified and further sub-speciated using the mass 3210 gene. Antimicrobial susceptibility was tested using broth microdilution and resistance genes erm(41), rrs, rrl, gyrA, and gyrB were studied for mutations. Majority were susceptible to amikacin, azithromycin, clarithromycin, and moxifloxacin [MAB: 100%, 100%, 100%, 81.8%, respectively; M. massiliense (MAM): 100%, 100%, 100%, 60%, respectively]. 50% MAM and 63.6% MAB were susceptible to cefoxitin; 60% MAM and 45.5% MAB were susceptible to ciprofloxacin; 72.7% MAB, and 10%MAM were susceptible to doxycycline. Inducible resistance to azithromycin and clarithromycin was found in 27.3%MAB and 30% MAM. 42.9% MAB complex isolates were MDR. Macrolide resistant MAB and MAM had T28 sequevar, showing functional erm(41) responsible for inducible resistance. Unexpectedly, full length erm(41) was found in MAM. Therrl gene in these isolates showed no point mutations, indicating T28 sequevar as cause of inducible resistance. All fluoroquinolone resistant isolates showed Ala-83 in gyrA fluoroquinolone resistant-dependent region (QRDR) and Arg-447 and Asn-464 in gyrB QRDR. These are associated with resistance to the drug.

scholarly journals Prevalence and Molecular Characterization of Second-Line Drugs Resistance among Multidrug-ResistantMycobacterium tuberculosisIsolates in Southwest of China

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Y. Hu ◽  
L. Xu ◽  
Y. L. He ◽  
Y. Pang ◽  
N. Lu ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Multidrug Resistant ◽  
Rapid Screening ◽  
Second Line ◽  
Tb Treatment ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Improper Use ◽  
Mdr Tb

This study aimed to investigate the prevalence of multidrug-resistant tuberculosis (MDR-TB) isolates resistant to the second-line antituberculosis drugs (SLDs) and its association with resistant-related gene mutations inMycobacterium tuberculosis(M.tb) isolates from Southwest of China. There were 81 isolates resistant to at least one of the SLDs among 156 MDR-TB isolates (81/156, 51.9%). The rates of general resistance to each of the drugs were as follows: OFX (66/156, 42.3%), KAN (26/156, 16.7%), CAP (13/156, 8.3%), PTO (11/156, 7.1%), PAS (22/156, 14.1%), and AMK (20/156, 12.8%). Therefore, the most predominant pattern was resistant to OFX compared with other SLDs (P<0.001). The results of sequencing showed that 80.2% OFX-resistant MDR-TB isolates containedgyrAmutation and 88.5% KAN-resistant isolates hadrrsmutations with the most frequent mutation being A1401G. These results suggest that improper use of SLDs especially OFX is a real threat to effective MDR-TB treatment not only in China but also in the whole world. Furthermore the tuberculosis control agencies should carry out SLDs susceptibility testing and rapid screening in a broader population of TB patients immediately and the SLDs should be strictly regulated by the administration in order to maintain their efficacy to treat MDR-TB.

scholarly journals Molecular Characterization of Multidrug-Resistant Mycobacterium tuberculosis Isolates from China

2014 ◽  
Vol 58 (4) ◽  
pp. 1997-2005 ◽  
Author(s):  
Li-Li Zhao ◽  
Yan Chen ◽  
Hai-Can Liu ◽  
Qiang Xia ◽  
Xiao-Cui Wu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Multidrug Resistant ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Beijing Family ◽  
Phenotypic Data ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb

ABSTRACTTo investigate the molecular characterization of multidrug-resistant tuberculosis (MDR-TB) isolates from China and the association of specific mutations conferring drug resistance with strains of different genotypes, we performed spoligotyping and sequenced nine loci (katG,inhA, theoxyR-ahpCintergenic region,rpoB,tlyA,eis,rrs,gyrA, andgyrB) for 128 MDR-TB isolates. Our results showed that 108 isolates (84.4%) were Beijing family strains, 64 (59.3%) of which were identified as modern Beijing strains. Compared with the phenotypic data, the sensitivity and specificity of DNA sequencing were 89.1% and 100.0%, respectively, for isoniazid (INH) resistance, 93.8% and 100.0% for rifampin (RIF) resistance, 60.0% and 99.4% for capreomycin (CAP) resistance, 84.6% and 99.4% for kanamycin (KAN) resistance, and 90.0% and 100.0% for ofloxacin (OFX) resistance. The most prevalent mutations among the MDR-TB isolates werekatG315,inhA15,rpoB531, -526, and -516,rrs1401,eis-10, andgyrA94, -90, and -91. Furthermore, there was no association between specific resistance-conferring mutations and the strain genotype. These findings will be helpful for the establishment of rapid molecular diagnostic methods to be implemented in China.

In vitro susceptibility of Mycobacterium abscessus complex and feasibility of standardizing treatment regimens

2020 ◽  
Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Joelle Go ◽  
Sally Ng ◽  
Yit Er Tang ◽  
...  
Keyword(s):  
Retrospective Review ◽  
Susceptibility Testing ◽  
Mycobacterium Abscessus ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Treatment Regimens ◽  
Mycobacterium Abscessus Complex ◽  
Additional Testing

Abstract Objectives To determine the in vitro susceptibility of members of the Mycobacterium abscessus complex to routinely tested antibiotics and to an extended antibiotic panel. Methods Non-duplicate isolates for which susceptibility testing results were available were included in this study. Retrospective laboratory records were reviewed, including tigecycline susceptibility results, and testing was performed with additional drugs, including vancomycin, dalbavancin, telavancin, oritavancin, rifabutin, delafloxacin, eravacycline, clofazimine and bedaquiline using broth microdilution (Sensititre, Thermo Fisher). Results A total of 218 M. abscessus complex isolates were included for retrospective review, of which 151 were respiratory isolates. Of these 218 isolates, 211 were available for additional testing with the extended antibiotic panel. Of these, 146 were respiratory isolates. One isolate had a vancomycin MIC of 2 mg/L and MICs of all other isolates were &gt;8 mg/L. All isolates had MICs of &gt;8 mg/L for oritavancin, dalbavancin and telavancin. One isolate had a delafloxacin MIC of 4 mg/L and MICs of all other isolates were &gt;8 mg/L. The MIC50/MIC90s of rifabutin, tigecycline, eravacycline, clofazimine and bedaquiline were 16/32, 0.5/1, 0.12/0.25, 0.12/0.25 and 0.06/0.12 mg/L, respectively. Conclusions In vitro activity was demonstrated for clofazimine, bedaquiline and eravacycline, indicating potential for inclusion as standardized therapy for M. abscessus complex infections.

scholarly journals Identification and Characterization of Class 1 Integron Resistance Gene Cassettes among Salmonella Strains Isolated from Imported Seafood

2008 ◽  
Vol 75 (4) ◽  
pp. 1192-1196 ◽  
Author(s):  
Ashraf A. Khan ◽  
Elizabeth Ponce ◽  
M. S. Nawaz ◽  
Chorng-Ming Cheng ◽  
Junaid A. Khan ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Southern Hybridization ◽  
Multidrug Resistant ◽  
The Philippines ◽  
Streptomycin Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Identification And Characterization ◽  
Multiple Antibiotics

ABSTRACT A total of 210 Salmonella isolates, representing 64 different serovars, were isolated from imported seafood samples, and 55/210 isolates were found to be resistant to at least one antibiotic. Class 1 integrons from three multidrug-resistant Salmonella enterica strains (Salmonella enterica serovars Newport [strain 62], Typhimurium var. Copenhagen [strain 629], and Lansing [strain 803], originating from Hong Kong, the Philippines, and Taiwan, respectively) were characterized. Southern hybridization of plasmids isolated from these strains, using a class 1 integron probe, showed that trimethoprim-sulfamethoxazole and streptomycin resistance genes were located on a megaplasmid in strain 629. Our study indicates that imported seafood could be a reservoir for Salmonella isolates resistant to multiple antibiotics.

scholarly journals Identification, Synthesis, Isolation and Spectral Characterization of Multidrug-Resistant Tuberculosis (MDR-TB) Related Substances

2018 ◽  
Vol 08 (02) ◽  
pp. 190-207
Author(s):  
Sureshbabu Jayachandra ◽  
Madhuresh Kumar Sethi ◽  
Vipin Kumar Kaushik ◽  
Vijayakrishna Ravi ◽  
Saiprasad Kottolla ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Spectral Characterization ◽  
Related Substances ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb

scholarly journals Characterization of Mutations Associated with Streptomycin Resistance in Multidrug-Resistant Mycobacterium tuberculosis in Zambia

Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1169
Author(s):  
Precious Bwalya ◽  
Tomoyuki Yamaguchi ◽  
Eddie Samuneti Solo ◽  
Joseph Yamweka Chizimu ◽  
Grace Mbulo ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Streptomycin Resistance ◽  
University Teaching ◽  
Reference Laboratory ◽  
Tb Treatment ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Mdr Tb ◽  
The University

Streptomycin (STR) is recommended for the management of multidrug-resistant tuberculosis (MDR-TB). Streptomycin resistance-conferring mutation types and frequency are shown to be influenced by genotypes of circulating strains in a population. This study aimed to characterize the mutations in MDR-TB isolates and examine their relationship with the genotypes in Zambia. A total of 138 MDR-TB isolates stored at the University Teaching Hospital Tuberculosis Reference Laboratory in Zambia were analyzed using spoligotyping and sequencing of STR resistance-associated genes. Streptomycin resistance was observed in 65.9% (91/138) of MDR-TB isolates. Mutations in rpsL, rrs, and gidB accounted for 33%, 12.1%, and 49.5%, respectively. Amino acid substitution K43R in rpsL was strongly associated with the CAS1_Kili genotype (p < 0.0001). The combination of three genes could predict 91.2% of STR resistance. Clustering of isolates based on resistance-conferring mutations and spoligotyping was observed. The clustering of isolates suggests that the increase in STR-resistant MDR-TB in Zambia is largely due to the spread of resistant strains from inadequate treatment. Therefore, rapid detection of STR resistance genetically is recommended before its use in MDR-TB treatment in Zambia.

scholarly journals Epidemic and molecular characterization of fluoroquinolone-resistant Shigella dysenteriae 1 isolates from calves with diarrhea

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mingze Cao ◽  
Weiwei Wang ◽  
Liwei Zhang ◽  
Guanhui Liu ◽  
Xuzheng Zhou ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Virulence Genes ◽  
Point Mutations ◽  
Multidrug Resistant ◽  
Gansu Province ◽  
Quinolone Resistance ◽  
Shigella Dysenteriae ◽  
Fluoroquinolone Resistance ◽  
And Control

Abstract Background The widespread distribution of antimicrobial-resistant Shigella has become a recurrent challenge in many parts of the developing world. Previous studies indicate that the host of Shigella has expanded from humans to animals. This study aimed to investigate the prevalence of fluoroquinolone resistance and associated molecular characterization of S. dysenteriae 1 isolated from calves. Results All 38 unduplicated S. dysenteriae 1 isolates were collected from calves in Gansu Province from October 2014 to December 2016. According to MLST and PFGE analysis, these isolates were separated into 4 and 28 genotypes, respectively. The most common STs identified were ST228 (34.21%, 13/38) and ST229 (39.47%, 15/38), which were first found in the present study. All isolates harbored virulence genes, and the incidence of the seven virulence genes were ipaH (100%), ipaBCD (92.11%), stx (73.68%), ial (57.89%), sen (28.95%), set1A and set1B (0%). According to the results of antimicrobial susceptibilities, 76.32% (29/38) were resistant to fluoroquinolone and showed multidrug resistance. In a study on the polymorphism of quinolone resistance–determining region (QRDR) of gyrA/B and parC/E genes, we identified two mutations in gyrA (Ser83 → Leu and Asp87 → Asn) and parC (Ser80 → Ile and Ser83 → Leu), respectively. Among them, 55.17% (16/29) of resistant strains had the gyrA point mutations (Ser83 → Leu) and parC point mutation (Ser83 → Leu). Moreover, 41.38% (12/29) of isolates had all five point mutations of gyrA and parC. In addition, the prevalence of the plasmid-mediated quinolone resistance (PMQR) determinant genes was also investigated. All 29 fluoroquinolone-resistant isolates were positive for the aac (6′)-Ib-cr gene but negative for qepA, except for SD001. In addition, only 6 (20.69%, 6/29) isolates harbored the qnr gene, including two with qnrB (6.90%, 2/29) and four with qnrS (13.79%, 4/29). Conclusion Given the increased common emergence of multidrug resistant isolates, uninterrupted surveillance will be necessary to understand the actual epidemic burden and control this infection.

scholarly journals Epidemic and molecular characterization of fluoroquinolone-resistant Shigella dysenteriae 1 isolates from calves with diarrhea

2020 ◽  
Author(s):  
Mingze Cao ◽  
Weiwei Wang ◽  
Liwei Zhang ◽  
Guanhui Liu ◽  
Xuzheng Zhou ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Virulence Genes ◽  
Point Mutations ◽  
Multidrug Resistant ◽  
Gansu Province ◽  
Quinolone Resistance ◽  
Shigella Dysenteriae ◽  
Fluoroquinolone Resistance ◽  
And Control

Abstract Background: The widespread distribution of antimicrobial-resistant Shigella has become a recurrent challenge in many parts of the developing world. Previous studies indicate that the host of Shigella has expanded from humans to animals. This study aimed to investigate the prevalence of fluoroquinolone resistance and associated molecular characterization of S. dysenteriae 1 isolated from calves. Results: All 38 unduplicated S. dysenteriae 1 isolates were collected from calves in Gansu Province from October 2014 to December 2016. According to MLST and PFGE analysis, these isolates were separated into 4 and 28 genotypes, respectively. The most common STs identified were ST228 (34.21%, 13/38) and ST229 (39.47%, 15/38), which were first found in the present study. All isolates harbored virulence genes, and the incidence of the seven virulence genes were ipaH (100%), ipaBCD (92.11%), stx (73.68%), ial (57.89%), sen (28.95%), set1A and set1B (0%). According to the results of antimicrobial susceptibilities, 76.32% (29/38) were resistant to fluoroquinolone and showed multidrug resistance. In a study on the polymorphism of quinolone resistance–determining region (QRDR) of gyrA/B and parC/E genes, we identified two mutations in gyrA (Ser83→Leu and Asp87→Asn) and parC (Ser80→Ile and Ser83→Leu), respectively. Among them, 55.17% (16/29) of resistant strains had the gyrA point mutations (Ser83→Leu) and parC point mutation (Ser83→Leu). Moreover, 41.38% (12/29) of isolates had all five point mutations of gyrA and parC. In addition, the prevalence of the plasmid-mediated quinolone resistance (PMQR) determinant genes was also investigated. All 29 fluoroquinolone-resistant isolates were positive for the aac(6’)-Ib-cr gene but negative for qepA, except for SD001. In addition, only 6 (20.69%, 6/29) isolates harbored the qnr gene, including two with qnrB (6.90%, 2/29) and four with qnrS (13.79%, 4/29). Conclusion: Given the increased common emergence of multidrug resistant isolates, uninterrupted surveillance will be necessary to understand the actual epidemic burden and control this infection.

scholarly journals Predominance of clarithromycin-susceptible Mycobacterium massiliense subspecies: Characterization of the Mycobacterium abscessus complex at a tertiary acute care hospital

2017 ◽  
Vol 66 (10) ◽  
pp. 1443-1447 ◽  
Author(s):  
Ka Lip Chew ◽  
Janet W. S. Cheng ◽  
Nurul Hudaa Osman ◽  
Raymond T. P. Lin ◽  
Jeanette W. P. Teo
Keyword(s):  
Acute Care ◽  
Acute Care Hospital ◽  
Mycobacterium Abscessus ◽  
Care Hospital ◽  
Mycobacterium Massiliense ◽  
Mycobacterium Abscessus Complex
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