scholarly journals Emergence of multidrug-resistantMycobacterium simiae: An in vitro study from a regional tuberculosis reference laboratory in Iran

2019 ◽  
Author(s):  
Mohammad Javad Nasiri ◽  
Sirus Amini ◽  
Zahra Nikpor ◽  
Samaneh Arefzadeh ◽  
Mohammad Mosavi ◽  
...  
Keyword(s):  
Drug Testing ◽  
In Vitro Study ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Reference Laboratory ◽  
In Vitro Susceptibility ◽  
Susceptibility Patterns

AbstractIntroductionMycobacterium simiaeis an emerging pathogen in Iran and little is known about drug susceptibility patterns of this pathogen.Materials and methodsTwenty five clinical isolates ofM. simiaefrom 80 patients with confirmed NTM pulmonary disease were included in this study. For drug susceptibility testing (DST), proportional and broth microdilution methods were used according to the clinical and laboratory standards institute (CLSI) guideline.ResultsAll clinical isolates ofM. simiaewere resistant to isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, ciprofloxacin and clarithromycin. They also were highly resistant to ofloxacin (80%). Susceptibility to ofloxacin was only noted in the 5 isolates.ConclusionsClinical isolates ofM.simiaewere multidrug resistant, and had different drug susceptibility patterns than previously published studies. DST results can assist in selecting more appropriate treatment regimens. Newer drugs with proven clinical efficacy correlating with in vitro susceptibility should be substituted with first- and second line anti-TB drug testing.

Drug susceptibility testing of Mycobacterium simiae: An emerging pathogen in Iran

2020 ◽  
Vol 20 ◽  
Author(s):  
Mohammad Javad Nasiri ◽  
Sirus Amini ◽  
Zahra Nikpor ◽  
Samaneh Arefzadeh ◽  
Seyyed Mohammad Javad Mousav ◽  
...  
Keyword(s):  
Drug Testing ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Emerging Pathogen ◽  
Treatment Regimens ◽  
Appropriate Treatment ◽  
Susceptibility Patterns

Introduction: Mycobacterium simiaeis an emerging pathogen in Iran and little is known about drug susceptibility patterns of this pathogen. Materials and methods: Twenty-five clinical isolates of M. simiaefrom 80 patients with confirmed NTM pulmonary disease were included in this study. For drug susceptibility testing (DST), proportional and broth microdilution methods were used according to the clinical and laboratory standards institute (CLSI) guideline. Results: All clinical isolates of M. simiaewere resistant to isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, ciprofloxacin, and clarithromycin. They also were highly resistant to ofloxacin (80%). Susceptibility to ofloxacin was only noted in the 5 isolates. Conclusions: Clinical isolates of M. simiae were multidrug-resistant, and had different drug susceptibility patterns than previously published studies. DST results can assist in selecting more appropriate treatment regimens. Newer drugs with proven clinical efficacy correlating with in vitrosusceptibility should be substituted with first-and second-line anti-TB drug testing.

scholarly journals Molecular epidemiology, in vitro susceptibility and exoenzyme screening of Malassezia clinical isolates

2020 ◽  
Vol 69 (3) ◽  
pp. 436-442 ◽  
Author(s):  
Wei Li ◽  
Zi-Wei Zhang ◽  
Yun Luo ◽  
Ni Liang ◽  
Xiao-Xue Pi ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Synergistic Effects ◽  
Extracellular Enzyme ◽  
Drug Susceptibility ◽  
Clinical Isolates ◽  
Sequencing Analysis ◽  
In Vitro Susceptibility ◽  
Major Species ◽  
Malassezia Globosa

Introduction. Malassezia folliculitis (MF) and pityriasis versicolor (PV) are common dermatoses caused by Malassezia species. Their molecular epidemiology, drug susceptibility and exoenzymes are rarely reported in China. Aim. To investigate the molecular epidemiology, drug susceptibility and enzymatic profile of Malassezia clinical isolates. Methodology. Malassezia strains were recovered from MF and PV patients and healthy subjects (HS) and identified by sequencing analysis. The minimum inhibitory concentrations (MICs) of nine antifungals (posaconazole, voriconazole, itraconazole, fluconazole, ketoconazole, miconazole, bifonazole, terbinafine and caspofungin) and tacrolimus, the interactions between three antifungals (itraconazole, ketoconazole and terbinafine) and tacrolimus, and the extracellular enzyme profile were evaluated using broth and checkerboard microdilution and the Api-Zym system, respectively. Results. Among 392 Malassezia isolates from 729 subjects (289 MF, 218 PV and 222 HS), Malassezia furfur and Malassezia globosa accounted for 67.86 and 18.88 %, respectively. M. furfur was the major species in MF and PV patients and HS. Among 60M. furfur and 50M. globosa strains, the MICs for itraconazole, posaconazole, voriconazole and ketoconazole were <1 μg ml−1. M. furfur was more susceptible to itraconazole, terbinafine and bifonazole but tolerant to miconazole compared with M. globosa (P<0.05). Synergistic effects between terbinafine and itraconazole or between tacrolimus and itraconazole, ketoconazole or terbinafine occurred in 6, 7, 6 and 9 out of 37 strains, respectively. Phosphatases, lipases and proteases were mainly secreted in 51 isolates. Conclusions. Itraconazole, posaconazole, voriconazole and ketoconazole are theagents against which there is greatest susceptibility. Synergistic effects between terbinafine and itraconazole or tacrolimas and antifungals may be irrelevant to clinical application. Overproduction of lipases could enhance the skin inhabitation of M. furfur.

scholarly journals Volatile Oils ofNepeta tenuifolia(Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  
Keyword(s):  
Essential Oils ◽  
In Vitro Study ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Gram Negative ◽  
E Coli ◽  
Wide Range ◽  
Main Component ◽  
Reference Strains

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.

scholarly journals Speeding up the diagnosis of multidrug-resistant tuberculosis in a high-burden region with the use of a commercial line probe assay

2019 ◽  
Vol 45 (2) ◽  
Author(s):  
Angela Pires Brandao ◽  
Juliana Maira Watanabe Pinhata ◽  
Rosangela Siqueira Oliveira ◽  
Vera Maria Neder Galesi ◽  
Helio Hehl Caiaffa-Filho ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Reference Laboratory ◽  
Line Probe Assay ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Commercial Line ◽  
Probe Assay

ABSTRACT Objective: To evaluate the rapid diagnosis of multidrug-resistant tuberculosis, by using a commercial line probe assay for rifampicin and isoniazid detection (LPA-plus), in the routine workflow of a tuberculosis reference laboratory. Methods: The LPA-plus was prospectively evaluated on 341 isolates concurrently submitted to the automated liquid drug susceptibility testing system. Results: Among 303 phenotypically valid results, none was genotypically rifampicin false-susceptible (13/13; 100% sensitivity). Two rifampicin-susceptible isolates harboured rpoB mutations (288/290; 99.3% specificity) which, however, were non-resistance-conferring mutations. LPA-plus missed three isoniazid-resistant isolates (23/26; 88.5% sensitivity) and detected all isoniazid-susceptible isolates (277/277; 100% specificity). Among the 38 (11%) invalid phenotypic results, LPA-plus identified 31 rifampicin- and isoniazid-susceptible isolates, one isoniazid-resistant and six as non-Mycobacterium tuberculosis complex. Conclusions: LPA-plus showed excellent agreement (≥91%) and accuracy (≥99%). Implementing LPA-plus in our setting can speed up the diagnosis of multidrug-resistant tuberculosis, yield a significantly higher number of valid results than phenotypic drug susceptibility testing and provide further information on the drug-resistance level.

scholarly journals Disparities in Capreomycin Resistance Levels Associated with therrsA1401G Mutation in Clinical Isolates of Mycobacterium tuberculosis

2014 ◽  
Vol 59 (1) ◽  
pp. 444-449 ◽  
Author(s):  
Analise Z. Reeves ◽  
Patricia J. Campbell ◽  
Melisa J. Willby ◽  
James E. Posey
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Strong Predictor ◽  
Critical Concentration ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Cross Resistance ◽  
Second Line ◽  
Content Type

ABSTRACTAs the prevalence of multidrug-resistant and extensively drug-resistant tuberculosis strains continues to rise, so does the need to develop accurate and rapid molecular tests to complement time-consuming growth-based drug susceptibility testing. Performance of molecular methods relies on the association of specific mutations with phenotypic drug resistance and while considerable progress has been made for resistance detection of first-line antituberculosis drugs, rapid detection of resistance for second-line drugs lags behind. TherrsA1401G allele is considered a strong predictor of cross-resistance between the three second-line injectable drugs, capreomycin (CAP), kanamycin, and amikacin. However, discordance is often observed between therrsA1401G mutation and CAP resistance, with up to 40% ofrrsA1401G mutants being classified as CAP susceptible. We measured the MICs to CAP in 53 clinical isolates harboring therrsA1401G mutation and found that the CAP MICs ranged from 8 μg/ml to 40 μg/ml. These results were drastically different from engineered A1401G mutants generated in isogenicMycobacterium tuberculosis, which exclusively exhibited high-level CAP MICs of 40 μg/ml. These data support the results of prior studies, which suggest that the critical concentration of CAP (10 μg/ml) used to determine resistance by indirect agar proportion may be too high to detect all CAP-resistant strains and suggest that a larger percentage of resistant isolates could be identified by lowering the critical concentration. These data also suggest that differences in resistance levels among clinical isolates are possibly due to second site or compensatory mutations located elsewhere in the genome.

scholarly journals Mycobacterium Tuberculosis Strain Lineage in Mixed Tribal Population Across India and Andaman Nicobar Island

2021 ◽  
Author(s):  
Azger Dusthackeer V. N. ◽  
Azger Dusthackeer V. N. ◽  
Ashok Kumar ◽  
Kannappan Kannappan Sucharitha ◽  
S. Shivakumar ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Small Sample ◽  
Clinical Isolates ◽  
Nicobar Island ◽  
Tribal Population ◽  
Indian States ◽  
Mdr Tb

Abstract In India, the tribal population constitutes almost 8.6% of the nation’s total population. This study attempts to provide information pertaining to the TB strain diversity, its public health implications, and distribution among the tribal population in 10 Indian states and Andaman & Nicobar (A&N) Island. Clinical isolates were received from 66 villages (10 states and island). A total of 78 M. tuberculosis clinical isolates were received from 10 different states and A&N Island. Among these, 16 different strains were observed. The major M. tuberculosis strains spoligotype belong to the Beijing, CAS1_DELHI, and EAI5 family followed by EAI1_SOM, EAI6_BGD1, LAM3, LAM6, LAM9, T1, T2, U strains. Drug-susceptibility testing (DST) results showed almost 15.4% of clinical isolates found to be resistant to isoniazid (INH) or rifampicin (RMP) + INH. Predominant multidrug-resistant tuberculosis (MDR-TB) isolates seem to be Beijing strain. Beijing, CAS1_DELHI, EAI3_IND, and EAI5 were the principal strains infecting mixed tribal populations across India. Despite the small sample size, this study has demonstrated higher diversity among the TB strains with significant MDR-TB findings. Prevalence of Beijing MDR-TB strains in Central, Southern, Eastern India and A&N Island indicates the transmission of the TB strains.

scholarly journals Comparative genomics and antimicrobial resistance profiling of Elizabethkingia isolates reveals nosocomial transmission and in vitro susceptibility to fluoroquinolones, tetracyclines and trimethoprim-sulfamethoxazole

2020 ◽  
Author(s):  
Delaney Burnard ◽  
Letitia Gore ◽  
Andrew Henderson ◽  
Ama Ranasinghe ◽  
Haakon Bergh ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
High Mortality ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Hospital Environment ◽  
Nosocomial Transmission ◽  
Intrinsic Resistance ◽  
In Vitro Susceptibility ◽  
Global Strain

AbstractThe Elizabethkingia genus has gained global attention in recent years as a nosocomial pathogen. Elizabethkingia spp. are intrinsically multidrug resistant, primarily infect immunocompromised individuals, and are associated with high mortality (∼20-40%). Although Elizabethkingia infections appear sporadically worldwide, gaps remain in our understanding of transmission, global strain relatedness and patterns of antimicrobial resistance. To address these knowledge gaps, 22 clinical isolates collected in Queensland, Australia, over a 16-year period along with six hospital environmental isolates were examined using MALDI-TOF MS (VITEK® MS) and whole-genome sequencing to compare with a global strain dataset. Phylogenomic reconstruction against all publicly available genomes (n=100) robustly identified 22 E. anophelis, three E. miricola, two E. meningoseptica and one E. bruuniana from our isolates, most with previously undescribed diversity. Global relationships show Australian E. anophelis isolates are genetically related to those from the USA, England and Asia, suggesting shared ancestry. Genomic examination of clinical and environmental strains identified evidence of nosocomial transmission in patients admitted several months apart, indicating probable infection from a hospital reservoir. Furthermore, broth microdilution of the 22 clinical Elizabethkingia spp. isolates against 39 antimicrobials revealed almost ubiquitous resistance to aminoglycosides, carbapenems, cephalosporins and penicillins, but susceptibility to minocycline, levofloxacin and trimethoprim/sulfamethoxazole. Our study demonstrates important new insights into the genetic diversity, environmental persistence and transmission of Australian Elizabethkingia species. Furthermore, we show that Australian isolates are highly likely to be susceptible to minocycline, levofloxacin and trimethoprim/sulfamethoxazole, suggesting that these antimicrobials may provide effective therapy for Elizabethkingia infections.ImportanceElizabethkingia are a genus of environmental Gram-negative, multidrug resistant, opportunistic pathogens. Although an uncommon cause of nosocomial and community-acquired infections, Elizabethkingia spp. are known to infect those with underlying co-morbidities and/or immunosuppression, with high mortality rates of ∼20-40%. Elizabethkingia have a presence in Australian hospitals and patients; however, their origin, epidemiology, and antibiotic resistance profile of these strains is poorly understood. Here, we performed phylogenomic analyses of clinical and hospital environmental Australian Elizabethkingia spp., to understand transmission and global relationships. Next, we performed extensive minimum inhibitory concentration testing to determine antimicrobial susceptibility profiles. Our findings identified a highly diverse Elizabethkingia population in Australia, with many being genetically related to international strains. A potential transmission source was identified within the hospital environment where two transplant patients were infected and three E. anophelis strains formed a clonal cluster within the phylogeny. Furthermore, near ubiquitous susceptibility to tetracyclines, fluoroquinolones and trimethoprim/sulfamethoxazole was observed in clinical isolates. We provide new insights into the origins, transmission and epidemiology of Elizabethkingia spp., in addition to understanding their intrinsic resistance profiles and potential effective treatment options, which has implications to managing infections and detecting outbreaks globally.

scholarly journals Effect of Piper nigrum (Linn.) seeds extract and second line anti-tuberculosis drugs on a few Mycobacterium tuberculosis strains

2021 ◽  
Vol 13 (1) ◽  
pp. 402-406
Author(s):  
G. V. Zodape ◽  
S. N. Dharmashale ◽  
V. S. Gaikwad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
In Vitro Study ◽  
Ethanolic Extract ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Piper Nigrum ◽  
Amino Salicylic Acid ◽  
Lowenstein Jensen ◽  
Proportion Method

Piper nigrum (Linn.) belonging to the family Piperaceae have been reported for its multitudinous medicinal values. The present study was undertaken to examine the direct effect of Ethionamide (ETH), Para amino salicylic acid (PAS), ethanolic extracts of P. nigrum on Mycobacterium tuberculosis (MTB) strain H37Rv and Multi drug-resistant (MDR)-strains-12, 19 and 21. The proportion method was used to detect the anti-mycobacterial drug susceptibility testing for mycobacteria using Lowenstein Jensen (LJ) medium. It was found that P. nigrum does not interfere with single or in the combination of both ETH and PAS showing the bioenhancer activity. In vitro study of ethanolic extract of P. nigrum observed that the extract inhibited the growth of H37Rv strains and MDR strains-12, MDR strains 19, and MDR strains 21. The present results will pave new avenues to find a new medicine that possesses P. nigrum alone or in combination with drugs to combat MDR-strains controlling tuberculosis.

scholarly journals Drug Susceptibility Testing of 31 Antimicrobial Agents on Rapidly Growing Mycobacteria Isolates from China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hui Pang ◽  
Guilian Li ◽  
Xiuqin Zhao ◽  
Haican Liu ◽  
Kanglin Wan ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
The Other ◽  
Clinical Isolates ◽  
Human Pathogens ◽  
Rapidly Growing Mycobacteria ◽  
Southern Chinese ◽  
Broth Microdilution Method

Objectives. Several species of rapidly growing mycobacteria (RGM) are now recognized as human pathogens. However, limited data on effective drug treatments against these organisms exists. Here, we describe the species distribution and drug susceptibility profiles of RGM clinical isolates collected from four southern Chinese provinces from January 2005 to December 2012.Methods. Clinical isolates (73) were subjected toin vitrotesting with 31 antimicrobial agents using the cation-adjusted Mueller-Hinton broth microdilution method. The isolates included 55M. abscessus, 11M. fortuitum, 3M. chelonae, 2M. neoaurum, and 2M. septicumisolates.Results.M. abscessus(75.34%) andM. fortuitum(15.07%), the most common species, exhibited greater antibiotic resistance than the other three species. The isolates had low resistance to amikacin, linezolid, and tigecycline, and high resistance to first-line antituberculous agents, amoxicillin-clavulanic acid, rifapentine, dapsone, thioacetazone, and pasiniazid.M. abscessusandM. fortuitumwere highly resistant to ofloxacin and rifabutin, respectively. The isolates showed moderate resistance to the other antimicrobial agents.Conclusions. Our results suggest that tigecycline, linezolid, clofazimine, and cefmetazole are appropriate choices forM. abscessusinfections. Capreomycin, sulfamethoxazole, tigecycline, clofazimine, and cefmetazole are potentially good choices forM. fortuituminfections. Our drug susceptibility data should be useful to clinicians.

scholarly journals 616. Evaluation of In Vitro Susceptibility to Ceftazidime/Avibactam of Clinical Isolates of Carbapenem Nonsusceptible Gram-Negative Bacilli from Colombia

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S287-S287
Author(s):  
Tobias M Appel ◽  
Maria F Mojica ◽  
Elsa De La Cadena ◽  
Christian Pallares ◽  
Maria Virginia Villegas
Keyword(s):  
Therapeutic Option ◽  
Generation Cephalosporin ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Clinical Isolates ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
Fixed Concentration ◽  
Class B

Abstract Background Ceftazidime/avibactam (CZA) is a combination of a third-generation cephalosporin and a diazabicyclooctane β-lactamase inhibitor, which is active against a broad range of class A, C and D β-lactamases. In Colombia, high rates of multidrug-resistant Enterobacteriaceae (Ent)and P. aeruginosa (Pae) have been reported. Of special concern are KPC enzymes endemic in Ent and found in Pae, which are associated with higher mortality and healthcare costs, as well as limited therapeutic options. Herein, we evaluate the susceptibility of clinical isolates of carbapenem nonsusceptible Ent (CNS-E) and Pae (CNS-P) to CZA with the aim of understanding its role as a therapeutic option for these bacteria. Methods Three hundred ninety-nine nonduplicate clinical isolates of carbapenem nonsusceptible Gram-negative bacilli were collected in 13 medical centers from 12 Colombian cities, from January 2016 to October 2017 (137 K. pneumoniae [Kpn], 76 E. coli, 34 Enterobacter spp., 21 S. marcescens [Sma] and 131 Pae). CNS-E was defined as minimum inhibitory concentrations (MIC) ≥1 mg/L for ertapenem and CNS-P was defined as MIC ≥4 mg/L for meropenem. MIC were determined by broth microdilution and interpreted according to current CLSI guidelines. CZA MIC were determined using double dilutions of ceftazidime and a fixed concentration of avibactam of 4 mg/L. Comparator agents were ceftazidime, cefepime, piperacillin/tazobactam, imipenem, meropenem, tigecycline (TGC), and fosfomycin (FOS). Results Antimicrobial activity of CZA and comparators is shown in Table 1. CZA susceptibility ranged from 69% in Kpn to 81% in Sma, whereas 49% of CNS-P were susceptible to CZA. In both, CNS-E and CNS-P, CZA was superior to all other tested β-lactam compounds. Notably, in CNS-E CZA susceptibility was comparable to FOS and TGC (except for TGC in Sma). Conclusion CZA is the most active β-lactam against CNS-E and CNS-P. CZA nonsusceptibility suggests the presence of other resistance mechanisms, such as class B β-lactamases that are not inhibited by avibactam, and which are more frequently reported in CNS-P. Our results highlight the key role of new agents such as CZA in KPC endemic countries and the need for surveillance studies to determine the nature of resistance mechanisms. Disclosures All authors: No reported disclosures.

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